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1.
J Synchrotron Radiat ; 25(Pt 5): 1371-1378, 2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-30179175

RESUMO

The new long duration experiment facility on beamline I11 at Diamond Light Source has been used to study the kinetics of sigma phase formation in three Cr-Co-Ni alloys. Diffraction data acquired during in situ exposure at 800°C for 50 d showed progressive increases in the sigma fraction. This was accompanied by changes in the proportions of the other phases, which differed markedly between the alloys studied. These results demonstrate the capabilities of the long duration facility for the study of metallurgical phenomena over periods of months to years, a capability not previously available at a synchrotron source.

2.
Philos Trans A Math Phys Eng Sci ; 374(2081)2016 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-29035252

RESUMO

This paper reviews atmospheric inputs of trace elements and nutrients to the oceans in the context of the GEOTRACES programme and provides new data from two Atlantic GEOTRACES cruises. We consider the deposition of nitrogen to the oceans, which is now dominated by anthropogenic emissions, the deposition of mineral dust and related trace elements, and the deposition of other trace elements which have a mixture of anthropogenic and dust sources. We then consider the solubility (as a surrogate for bioavailability) of the various elements. We consider briefly the sources, atmospheric transport and transformations of these elements and how this results in strong spatial deposition gradients. Solubility of the trace elements also varies systematically between elements, reflecting their sources and cycling, and for some trace elements there are also systematic gradients in solubility related to dust loading. Together, these effects create strong spatial gradients in the inputs of bioavailable trace elements to the oceans, and we are only just beginning to understand how these affect ocean biogeochemistry.This article is part of the themed issue 'Biological and climatic impacts of ocean trace element chemistry'.

3.
Philos Trans A Math Phys Eng Sci ; 374(2081)2016 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-29035268

RESUMO

The importance of the atmospheric deposition of biologically essential trace elements, especially iron, is widely recognized, as are the difficulties of accurately quantifying the rates of trace element wet and dry deposition and their fractional solubility. This paper summarizes some of the recent progress in this field, particularly that driven by the GEOTRACES, and other, international research programmes. The utility and limitations of models used to estimate atmospheric deposition flux, for example, from the surface ocean distribution of tracers such as dissolved aluminium, are discussed and a relatively new technique for quantifying atmospheric deposition using the short-lived radionuclide beryllium-7 is highlighted. It is proposed that this field will advance more rapidly by using a multi-tracer approach, and that aerosol deposition models should be ground-truthed against observed aerosol concentration data. It is also important to improve our understanding of the mechanisms and rates that control the fractional solubility of these tracers. Aerosol provenance and chemistry (humidity, acidity and organic ligand characteristics) play important roles in governing tracer solubility. Many of these factors are likely to be influenced by changes in atmospheric composition in the future. Intercalibration exercises for aerosol chemistry and fractional solubility are an essential component of the GEOTRACES programme.This article is part of the themed issue 'Biological and climatic impacts of ocean trace element chemistry'.

4.
Anal Bioanal Chem ; 398(1): 519-26, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20585941

RESUMO

Iodine has recently been of interest in atmospheric chemistry due to its role in tropospheric ozone depletion, modification of the HO/HO(2) ratio and aerosol nucleation. Gas-phase iodine chemistry is tightly coupled to the aerosol phase through heterogeneous reactions, which are dependent on iodine concentrations and speciation in the aerosol. To date, the only method available for total iodine determination in aerosols is collection on filters by impaction and quantification by neutron activation analysis (NAA). NAA is not widely available to all working groups and is costly to commission. Here, we present a method to determine total iodine concentrations in aerosol impact filter samples by combustion of filter sub-samples (approximately 5 cm(2)) at 1,000 degrees C, trapping in deionised water and quantification by UV/Vis spectroscopy. Both quartz and cellulose filters were analysed from four separate sampling campaigns. The method proved to be sensitive (3sigma = 6 ng absolute iodine approximately 3 pmol m(-3)) precise (RSD approximately 5%) and accurate, as determined by external and standard addition calibrations. Total iodine concentrations ranged from 10 pmol m(-3) over the Southern Ocean to 100 pmol m(-3) over the tropical Atlantic, in agreement with previous estimates. The soluble iodine concentration (extracted with water and measured by ICP-MS) was then subtracted from the total iodine to yield non-water-soluble iodine (NSI). The NSI fraction ranged from 20% to 53% of total iodine, and thus can be significant in some cases.


Assuntos
Aerossóis/análise , Atmosfera/análise , Iodo/análise , Espectrofotometria Ultravioleta , Água/análise , Aerossóis/química , Atmosfera/química , Celulose/química , Temperatura Alta , Iodo/química , Filtros Microporos , Quartzo/química , Água/química
5.
Acta Anaesthesiol Scand ; 54(7): 795-803, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20560885

RESUMO

Endoscopic sinus surgery is commonly performed and has a low risk of major complications. Intraoperative bleeding impairs surgical conditions and increases the risk of complications. Remifentanil appears to produce better surgical conditions than other opioid analgesics, and total intravenous anaesthesia with propofol may provide superior conditions to a volatile-based technique. Moderate hypotension with intraoperative beta blockade is associated with better operating conditions than when vasodilating agents are used. Tight control of CO(2) does not affect the surgical view. The use of a laryngeal mask may be associated with improved surgical conditions and a smoother emergence. It provides airway protection equivalent to that provided by an endotracheal tube in well-selected patients, but offers less protection from gastric regurgitation. Post-operatively, multimodal oral analgesia provides good pain relief, while long-acting local anaesthetics have been shown not to improve analgesia.


Assuntos
Anestesia , Cavidades Cranianas/cirurgia , Endoscopia/métodos , Seios Paranasais/cirurgia , Perda Sanguínea Cirúrgica/prevenção & controle , Humanos , Ventilação com Pressão Positiva Intermitente , Cuidados Intraoperatórios , Intubação Intratraqueal , Máscaras Laríngeas , Monitorização Intraoperatória , Relaxantes Musculares Centrais/farmacologia , Dor Pós-Operatória/tratamento farmacológico , Cuidados Pré-Operatórios
6.
J Clin Endocrinol Metab ; 94(1): 261-7, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18984670

RESUMO

CONTEXT: Visceral adipose tissue (AT) is known to confer a significantly higher risk of type 2 diabetes and cardiovascular disease. Epicardial AT has been shown to be related to cardiovascular disease and myocardial function through unidentified mechanisms. Epicardial AT expresses an inflammatory profile of proteins; however, the mechanisms responsible are yet to be elucidated. OBJECTIVES: The objectives of the study were to: 1) examine key mediators of the nuclear factor-kappaB (NFkappaB) and c-Jun N-terminal kinase (JNK) pathways in paired epicardial and gluteofemoral (thigh) AT from coronary artery disease (CAD) and control patients and 2) investigate circulating endotoxin levels in CAD and control subjects. DESIGN: Serums and AT biopsies (epicardial and thigh) were obtained from CAD (n = 16) and non-CAD (n = 18) patients. Inflammation was assessed in tissue and serum samples through Western blot, real-time PCR, ELISAs, and activity studies. RESULTS: Western blotting showed epicardial AT had significantly higher NFkappaB, inhibitory-kappaB kinase (IKK)-gamma, IKKbeta, and JNK-1 and -2 compared with thigh AT. Epicardial mRNA data showed strong correlations between CD-68 and toll-like receptor-2, toll-like receptor-4, and TNF-alpha. Circulating endotoxin was elevated in patients with CAD compared with matched controls [CAD: 6.80 +/- 0.28 endotoxin unit(EU)/ml vs. controls: 5.52 +/- 0.57 EU/ml; P<0.05]. CONCLUSION: Epicardial AT from patients with CAD shows increased NFkappaB, IKKbeta, and JNK expression compared with both CAD thigh AT and non-CAD epicardial AT, suggesting a depot-specific as well as a disease-linked response to inflammation. These studies implicate both NFkappaB and JNK pathways in the inflammatory profile of epicardial AT and highlight the role of the macrophage in the inflammation within this tissue.


Assuntos
Tecido Adiposo/fisiologia , Doença da Artéria Coronariana/complicações , Inflamação/etiologia , Proteínas Quinases JNK Ativadas por Mitógeno/fisiologia , NF-kappa B/fisiologia , Pericárdio/metabolismo , Idoso , Antígenos CD/genética , Antígenos de Diferenciação Mielomonocítica/genética , Endotoxinas/sangue , Feminino , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/análise , Masculino , Pessoa de Meia-Idade , NF-kappa B/análise , Fosforilação , RNA Mensageiro/análise , Receptor 4 Toll-Like/genética , Fator de Necrose Tumoral alfa/genética
7.
Diabetes Obes Metab ; 11(4): 285-92, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19175376

RESUMO

CONTEXT: Dipeptidyl peptidase IV (DPP-IV) inactivates the incretin hormone glucagon-like peptide. It can also affect the orexigenic hormone neuropeptide Y (NPY(1-36)) which is truncated by DPP-IV to NPY(3-36), as a consequence NPY's affinity changes from receptor Y1, which mediates the antilipolytic function of NPY, to other NPY receptors. Little is known whether DPP-IV inhibitors for the treatment of type 2 diabetic (T2DM) patients could influence these pathways. AIMS: To investigate the in vitro effects of NPY with DPP-IV inhibition in isolated abdominal subcutaneous (AbdSc) adipocytes on fat metabolism, and assessment of NPY receptor and DPP-IV expression in adipose tissue (AT). METHODS: Ex vivo human AT was taken from women undergoing elective surgery (body mass index: 27.5 (mean +/- s.d.) +/- 5 kg/m2, age: 43.7 +/- 10 years, n = 36). Isolated AbdSc adipocytes were treated with human recombinant (rh)NPY (1-100 nM) with and without DPP-IV inhibitor (1 M); glycerol release and tissue distribution of DPP-IV, Y1 and Y5 messenger RNA (mRNA) were measured and compared between lean and obese subjects. RESULTS AND CONCLUSION: rhNPY reduced glycerol release, an effect that was further enhanced by co-incubation with a DPP-IV inhibitor [control: 224 (mean +/- s.e.) +/- 37 micromol/l; NPY, 100 nM: 161 +/- 27 micromol/l**; NPY 100 nM/DPP-IV inhibitor, 1 M: 127 +/- 14 micromol/l**; **p < 0.01, n = 14]. DPP-IV was expressed in AbdSc AT and omental AT with relative DPP-IV mRNA expression lower in AbdSc AT taken from obese [77 +/- 6 signal units (SU)] vs. lean subjects (186 +/- 29 SU*, n = 10). Y1 was predominantly expressed in fat and present in all fat depots but higher in obese subjects, particularly the AbdSc AT-depot (obese: 1944 +/- 111 SU vs. lean: 711 +/- 112 SU**, n = 10). NPY appears to be regulated by AT-derived DPP-IV. DPP-IV inhibitors augment the antilipolytic effect of NPY in AT. Further studies are required to show whether this explains the lack of weight loss in T2DM patients treated with DPP-IV inhibitors.


Assuntos
Adipócitos/efeitos dos fármacos , Inibidores da Dipeptidil Peptidase IV/farmacologia , Neuropeptídeo Y/farmacologia , Gordura Subcutânea Abdominal/efeitos dos fármacos , Adipócitos/metabolismo , Adulto , Células Cultivadas , Dipeptidil Peptidase 4/metabolismo , Dipeptidil Peptidase 4/fisiologia , Feminino , Glicerol/metabolismo , Humanos , Lipólise/efeitos dos fármacos , Pessoa de Meia-Idade , Obesidade/metabolismo , Obesidade/patologia , Proteínas Recombinantes/farmacologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Gordura Subcutânea Abdominal/metabolismo , Gordura Subcutânea Abdominal/patologia
8.
Mol Cell Biol ; 12(12): 5541-7, 1992 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1448085

RESUMO

Growth hormone (GH) is an important regulator of postnatal growth, acting on a wide variety of target tissues. Here, we show that local production of GH in osteoblasts is able to stimulate bone growth directly without significant systemic effects. Mice were made transgenic by microinjection of an osteocalcin-human GH (osteocalcin-hGH) gene construct in which approximately 1,800 bp of the rat osteocalcin promoter was fused to the hGH gene. Five lines of transgenic mice, each with measurable amounts of serum hGH (ranging from 1 to 1,000 ng/ml), were analyzed. Northern (RNA) blot hybridization showed that the hGH transcript was detectable only in the bone. Further characterization of hGH mRNA distribution by in situ hybridization revealed that in neonates the most intense signal was found in periosteal osteoblasts, while in adults, trabecular and endosteal osteoblasts were favored. In one transgenic line (992-1), hGH was expressed at a much lower level and had minimal systemic effects; however, the local concentrations of hGH in bone were sufficient to stimulate bone growth in these animals.


Assuntos
Desenvolvimento Ósseo , Hormônio do Crescimento/genética , Osteoblastos/metabolismo , Osteocalcina/metabolismo , Animais , Northern Blotting , Clonagem Molecular , Hormônio do Crescimento/metabolismo , Hibridização In Situ , Camundongos , Camundongos Transgênicos , Especificidade de Órgãos/genética , Ratos
9.
J Natl Cancer Inst ; 60(2): 451-9, 1978 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-621758

RESUMO

C3H/HeJ mice bearing MC-80 fibrosarcomas were given immunotherapy consisting of multiple injections of a Vibrio cholerae neuraminidase (VCN)-treated tumor cell vaccine at a site remote from the established tumor. In five separate experiments we were unable to show either partial or complete tumor regression or prolongation of survival for vaccine-treated mice compared to appropriate controls. Further, the use of BCG in addition to VCN-treated tumor cells failed to show any therapeutic efficacy. We could not confirm the successful immunotherapy results reported by others despite multiple efforts of reproduce the immunotherapy model as carefully and precisely as possible.


Assuntos
Antígenos de Neoplasias/administração & dosagem , Metilcolantreno , Neuraminidase/farmacologia , Sarcoma Experimental/terapia , Animais , Vacina BCG/farmacologia , Contagem de Células , Feminino , Fibrossarcoma/terapia , Imunoterapia , Camundongos , Camundongos Endogâmicos C3H , Mitomicinas/farmacologia , Sarcoma Experimental/induzido quimicamente , Sarcoma Experimental/imunologia
10.
J Atmos Sci ; 73(5): 2039-2047, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-32747838

RESUMO

Reactive nitrogen emissions into the atmosphere are increasing due to human activities, affecting nitrogen deposition to the surface and impacting the productivity of terrestrial and marine ecosystems. An atmospheric chemistry-transport model (TM4-ECPL) is here used to calculate the global distribution of total nitrogen deposition, accounting for the first time for both its inorganic and organic fractions in gaseous and particulate phases, and past and projected changes due to anthropogenic activities. The anthropogenic and biomass burning ACCMIP historical and RCP6.0 and RCP8.5 emissions scenarios are used. Accounting for organic nitrogen (ON) primary emissions, the present-day global nitrogen atmospheric source is about 60% anthropogenic, while total N deposition increases by about 20% relative to simulations without ON primary emissions. About 20-25% of total deposited N is ON. About 10% of the emitted nitrogen oxides are deposited as ON instead of inorganic nitrogen (IN) as is considered in most global models. Almost a 3-fold increase over land (2-fold over the ocean) has been calculated for soluble N deposition due to human activities from 1850 to present. The investigated projections indicate significant changes in the regional distribution of N deposition and chemical composition, with reduced compounds gaining importance relative to oxidized ones, but very small changes in the global total flux. Sensitivity simulations quantify uncertainties due to the investigated model parameterizations of IN partitioning onto aerosols and of N chemically fixed on organics to be within 10% for the total soluble N deposition and between 25-35% for the dissolved ON deposition. Larger uncertainties are associated with N emissions.

11.
J Clin Oncol ; 6(9): 1491-500, 1988 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-3047339

RESUMO

We have previously reported the results of a randomized trial that demonstrated the survival benefit of adjuvant chemotherapy in the treatment of patients with high-grade extremity sarcomas compared with no chemotherapy. This regimen included doxorubicin, cyclophosphamide, and methotrexate. This report updates and extends our experience. The median follow-up of this trial is now 7.1 years and reveals a 5-year disease-free survival of 75% and 54% for chemotherapy and no chemotherapy groups, respectively (two-sided P [P2] = .037). The 5-year overall survival for patients in this trial was 83% and 60% for the chemotherapy and no chemotherapy groups, respectively, with a trend towards improved survival in the chemotherapy arm (P2 = .124). Because of doxorubicin-induced cardiomyopathy we performed a subsequent randomized trial comparing this high-dose regimen to reduced cumulative doses of doxorubicin and cyclophosphamide without methotrexate. Eighty-eight patients were entered into this trial which has a median follow-up of 4.4 years. The 5-year disease-free and overall survival for patients treated with the reduced doses of chemotherapy was 72% and 75%, respectively, and was not significantly different from the high-dose regimen. No patients developed congestive heart failure on this study. We conclude that adjuvant chemotherapy improves disease-free survival in patients with extremity soft-tissue sarcomas. The overall survival advantage in patients receiving adjuvant chemotherapy in our initial randomized high-dose chemotherapy trial has diminished though it continues to favor the chemotherapy group. A reduced-dose chemotherapy regimen was found to be comparable to the high-dose regimen.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Extremidades , Sarcoma/tratamento farmacológico , Neoplasias de Tecidos Moles/tratamento farmacológico , Ensaios Clínicos como Assunto , Terapia Combinada , Ciclofosfamida/administração & dosagem , Doxorrubicina/administração & dosagem , Esquema de Medicação , Seguimentos , Humanos , Metotrexato/administração & dosagem , Distribuição Aleatória , Sarcoma/mortalidade , Neoplasias de Tecidos Moles/mortalidade , Fatores de Tempo
12.
J Clin Oncol ; 16(1): 197-203, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9440743

RESUMO

PURPOSE: This randomized, prospective study assesses the impact of postoperative external-beam radiation therapy on local recurrence (LR), overall survival (OS), and quality of life after limb-sparing resection of extremity sarcomas. PATIENTS AND METHODS: Patients with extremity tumors and a limb-sparing surgical option were randomized to receive or not receive postoperative adjuvant external-beam radiotherapy. Patients with high-grade sarcomas received postoperative adjuvant chemotherapy whereas patients with low-grade sarcomas or locally aggressive nonmalignant tumors were randomized after surgery alone. RESULTS: Ninety-one patients with high-grade lesions were randomized; 47 to receive radiotherapy (XRT) and 44 to not receive XRT. With a median follow-up of 9.6 years, a highly significant decrease (P2 = .0028) in the probability of LR was seen with radiation, but no difference in OS was shown. Of 50 patients with low-grade lesions (24 randomized to resection alone and 26 to resection and postoperative XRT), there was also a lower probability of LR (P2 = .016) in patients receiving XRT, again, without a difference in OS. A concurrent quality-of-life study showed that extremity radiotherapy resulted in significantly worse limb strength, edema, and range of motion, but these deficits were often transient and had few measurable effects on activities of daily life or global quality of life. CONCLUSION: This study indicates that although postoperative external-beam radiotherapy is highly effective in preventing LRs, selected patients with extremity soft tissue sarcoma who have a low risk of LR may not require adjuvant XRT after limb-sparing surgery (LSS).


Assuntos
Extremidades , Recidiva Local de Neoplasia/prevenção & controle , Sarcoma/radioterapia , Sarcoma/cirurgia , Feminino , Seguimentos , Humanos , Masculino , Estudos Prospectivos , Qualidade de Vida , Radioterapia Adjuvante
13.
J Colloid Interface Sci ; 291(2): 319-25, 2005 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-16005012

RESUMO

This study investigates the reactivity and removal kinetics of Cu and Zn onto mixed mineral systems from aqueous solution related to acid mine drainage impacted areas. The sorbents used were kaolinite, Al-montmorillonite, goethite, and their mixtures. The effects of surface charge, proton coefficient, and sorption kinetics were studied at room temperature (23+/-2 degrees C). Using an empirical model, mineral mixing reduced the exchange of protons for sorbing ions and the acidity of the reactive sites, thus impeding Cu and Zn removal by proton exchange. Based on the amount of Cu and Zn sorbed on the mixed mineral suspensions at ionic strength 0.01 to 0.1 M and pH 4, it is suggested that Cu and Zn removal from aqueous solution was by both inner and outer sphere complexation. Mineral mixing reduced the transfer rate of Cu relative to the single mineral suspensions in both slow and fast reaction phases. The behavior of the mixed suspensions in Cu and Zn sorption suggest that different reactive sites were involved at the onset of sorption, becoming similar to those of the single mineral components over time.

14.
J Colloid Interface Sci ; 291(2): 326-33, 2005 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-16009366

RESUMO

This study investigates Cu and Zn removal onto binary mixed mineral sorbents from simulated wastewater, relevant to streams impacted by acid mine drainage and effluents. Mixed suspensions of kaolinite/montmorillonite and kaolinite/goethite exhibited different sorption behavior from the single mineral components, reducing Cu and Zn removal (except Cu sorbed on montmorillonite/goethite) over the range of pH investigated. Cu and Zn removal by the electrolyzed systems showed a complex response to increased ionic strength, which increased solid concentration, leading to lower Cu and Zn sorption. Enhanced Cu sorption on the montmorillonite/goethite as age increased may be attributed to increased hydroxylation of the mineral surface resulting in the formation of new reactive sites.

15.
Cardiovasc Res ; 19(9): 559-66, 1985 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-3899359

RESUMO

Aorto-iliac stenoses were characterised in terms of pressure drop and flow velocity in a canine model and in patients with occlusive arterial disease. Pressure above and below the stenosis was measured intra-arterially and flow related measurements were made at rest and during reactive hyperaemia in the dog, and following papaverine administration in patients. The addition of flow velocity information to the pressure drop across a stenosis gave an increased separation of stenoses in the experimental animal and also in man.


Assuntos
Arteriopatias Oclusivas/fisiopatologia , Velocidade do Fluxo Sanguíneo , Pressão Sanguínea , Animais , Aorta/fisiopatologia , Arteriopatias Oclusivas/diagnóstico , Modelos Animais de Doenças , Cães , Humanos , Artéria Ilíaca/fisiopatologia , Papaverina , Ultrassonografia/instrumentação
16.
Tissue Eng ; 5(3): 197-206, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10434068

RESUMO

A radioactive tracer technique was used to evaluate the in vivo mass transfer properties of a tissue engineered bioartificial organ. To obtain these measurements, bioartificial organs were first implanted in ten rats and allowed to vascularize for 4 weeks. After vascularization, radioactive inulin was placed within the cell chamber of the device. Following the addition of tracer, blood samples were taken over a 4-h time period and inulin levels were determined. The results of these experiments were interpreted using a compartmental model that describes the transport of inulin from the cell chamber, across the immunoisolation membrane, and into the neovascularized region contained within the adjacent scaffold material. Nonlinear regression analysis of the plasma inulin levels using a four-compartment pharmacokinetic model provided estimates of the membrane permeability, the product of the capillary wall surface area and capillary permeability, and the glomerular filtration rate (GFR). The permeability of the membrane was found to be 3.50 x 10(-5) +/- 1.15 x 10(-5) cm/sec (95% confidence interval, n = 10), which compares favorably to previous in vitro permeability data for this membrane. The capillary wall permeability was found to be 0. 0087 6 0.0029 cm(3)/sec/100 g of tissue. This compares well to a reported value for inulin of 0.01 cm(3)/sec/100 g of tissue. The GFR was found to be 0.44 +/- 0.07 ml/h/g BW, which compares well with a reported value of 0.40 ml/hr/g BW. The inulin tracer technique reported here is a useful tool for assessing the in vivo transport characteristics of a bioartificial organ as well as the vascularization within tissue engineered structures.


Assuntos
Órgãos Artificiais , Inulina/farmacocinética , Neovascularização Fisiológica , Animais , Radioisótopos de Carbono/farmacocinética , Taxa de Filtração Glomerular , Masculino , Modelos Biológicos , Permeabilidade , Ratos , Ratos Sprague-Dawley , Distribuição Tecidual
17.
Surgery ; 112(3): 536-43, 1992 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-1519170

RESUMO

We prospectively sampled 38 large soft tissue masses in 37 patients with both core needle biopsy (CNBX) and fine-needle aspiration (FNA) to determine the diagnostic utility of these biopsy methods. In 27 cases the histologic diagnosis made from the resected specimen was compared with the diagnosis based on the biopsy. CNBX correctly identified 16 of 16 malignant sarcomas and 10 of 11 benign masses (one was indeterminate). The grade of the sarcoma was determined correctly in every case. There were no false malignant or false benign CNBX diagnoses. FNA correctly classified 12 of 14 malignant sarcomas and four of 11 benign lesions. Diagnoses based on FNA were limited by a high proportion of samples, especially from benign lesions, that were inadequate for definitive diagnosis and by an inability to grade many malignant sarcomas. There were no significant complications resulting from the biopsies. We conclude that CNBX is a highly accurate, easily performed method for the diagnosis of large soft tissue masses that can be accomplished with minimal morbidity.


Assuntos
Biópsia por Agulha , Neoplasias de Tecidos Moles/patologia , Sucção/métodos , Adolescente , Adulto , Idoso , Biópsia por Agulha/efeitos adversos , Criança , Estudos de Avaliação como Assunto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Agulhas , Estudos Prospectivos , Sucção/instrumentação
18.
Surgery ; 97(5): 518-28, 1985 May.
Artigo em Inglês | MEDLINE | ID: mdl-2986304

RESUMO

The Tikhoff-Linberg resection is a limb-sparing surgical option to be considered for bony and soft-tissue tumors in and around the proximal humerus and shoulder girdle. Careful selection of patients whose tumor does not involve the neurovascular bundle in the axilla is required. The distal clavicle, upper humerus, and part or all of the scapula are resected. The tumor remains covered by the deltoid muscle plus portions of the muscles that arise from or insert into the resected specimen. In patients with tumors of the proximal humerus a custom prosthesis is used to maintain length and stabilize the distal humerus. Elbow flexion plus stability of the shoulder without the need of an orthosis may be achieved with muscle transfers. Function of the hand and forearm after Tikhoff-Linberg resection should be near normal. Review of results in 10 patients shows no local recurrences and excellent function. The major postoperative problem was nerve palsy. The Tikhoff-Linberg procedure should continue to be used for limb salvage in selected patients with tumors in or around the shoulder girdle.


Assuntos
Neoplasias Ósseas/cirurgia , Úmero/cirurgia , Osteossarcoma/cirurgia , Sarcoma/cirurgia , Adolescente , Adulto , Axila , Neoplasias Ósseas/reabilitação , Condrossarcoma/cirurgia , Clavícula/cirurgia , Feminino , Hemangiopericitoma/cirurgia , Histiocitoma Fibroso Benigno/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Próteses e Implantes , Escápula/cirurgia , Retalhos Cirúrgicos
19.
Surgery ; 97(3): 381-4, 1985 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-2983451

RESUMO

Intraoperative ultrasonography has not been used previously to locate an insulinoma that was not surgically palpable or that could not be seen by selective arteriography. In this report we described a patient with an insulinoma localized to the pancreatic head identified by transhepatic portal venous sampling but not by selective arteriography or palpation. At operation intraoperative ultrasonography demonstrated an 8 mm tumor in the pancreatic head and guided the successful enucleation.


Assuntos
Adenoma de Células das Ilhotas Pancreáticas/cirurgia , Insulinoma/cirurgia , Neoplasias Pancreáticas/cirurgia , Ultrassonografia/métodos , Adulto , Humanos , Hiperinsulinismo/sangue , Hiperinsulinismo/etiologia , Hipoglicemia/etiologia , Insulinoma/complicações , Insulinoma/diagnóstico , Período Intraoperatório , Neoplasias Pancreáticas/complicações , Neoplasias Pancreáticas/diagnóstico , Veia Porta
20.
Cell Transplant ; 6(6): 585-95, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9440868

RESUMO

An immunoisolation membrane formed by incorporating a high water content polyvinyl alcohol (PVA) hydrogel into a microporous polyether sulfone (PES) filter has been investigated in this study. The PVA hydrogel is formed in situ within the filter pores via glutaraldehyde (GA) crosslinking under acidic conditions. The tortuous nature of the microporous filter pores securely anchors the embedded hydrogel to provide excellent structural integrity. The high void fraction of the PES filter support (>80%) and high water content of the PVA hydrogel (>85% water by weight) allow excellent solute transport rates, while an appropriate level of glutaraldehyde crosslinking supplies the required molecular size selectivity. In vitro permeability measurements made with solutes covering a wide range of molecular sizes demonstrate high transport rates for small nutrient molecules with rapidly diminishing permeabilities above a molecular weight of approximately 1,000 Dalton. Implantation experiments show that the membrane properties are not deleteriously affected by prolonged in vivo exposure or common sterilization techniques. Thus, this hybrid hydrogel/filter membrane system offers a promising approach to the immunoisolation of implanted cells.


Assuntos
Materiais Biocompatíveis , Géis , Membranas Artificiais , Filtros Microporos , Álcool de Polivinil , Animais , Transplante de Células , Masculino , Cavidade Peritoneal , Permeabilidade , Ratos , Ratos Sprague-Dawley , Esterilização , Temperatura
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