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1.
Prague Med Rep ; 112(2): 132-6, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21699762

RESUMO

Hemobilia is a rare phenomenon. In this case report we present an emergent transcatheter glue embolization (in which N-butyl cyanoacrylate is used as an embolizing agent) due to arteriobilary fistula occurred following the laparoscopic cholecystectomy in a 41-year-old woman.


Assuntos
Colecistectomia Laparoscópica/efeitos adversos , Embolização Terapêutica , Embucrilato/uso terapêutico , Procedimentos Endovasculares , Vesícula Biliar/irrigação sanguínea , Hemobilia/etiologia , Hemorragia/etiologia , Adesivos Teciduais/uso terapêutico , Adulto , Fístula Biliar/etiologia , Fístula Biliar/terapia , Feminino , Hemorragia/terapia , Humanos , Fístula Vascular/etiologia , Fístula Vascular/terapia
2.
Prague Med Rep ; 111(3): 229-34, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20946723

RESUMO

Several types of abnormalities of the ribs have been reported. Many of these anomalies usually result in the correct diagnosis thanks to the characteristic radiological appearances. But some of the anomalies are rare and it is important to recognize and get accustomed to differing appearances of these osseous abnormalities in order to differentiate the pathological processes and to diagnose the syndromes which may accompany rib anomalies. The localized costovertebral anomaly with horn-like appearance, which has not yet been described in literature, is presented in this paper.


Assuntos
Costelas/anormalidades , Vértebras Torácicas/anormalidades , Adulto , Humanos , Radiografia Torácica , Costelas/diagnóstico por imagem , Vértebras Torácicas/diagnóstico por imagem , Adulto Jovem
3.
J Hazard Mater ; 162(2-3): 1073-80, 2009 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-18620805

RESUMO

Polyethyleneglycolmethacrylate (PEGMA) and vinylimidazole (VI) were used in order to obtain microspheres of PEGMA-VI copolymers that can be used in heavy metal removal applications. The obtained copolymers were characterized and their use as sorbents in heavy metal removal was investigated. In the first part of the study, PEGMA-VI microspheres were prepared by suspension polymerization method. The obtained swellable microspheres with 10-50 microm average diameter did not have permanent porosity according to the morphological and physicochemical determinations. The sizes of microspheres became smaller with increasing VI and cross-linker ethyleneglycoldimethacrylate (EGDMA) contents and increasing agitation rate. The VI content, EGDMA ratio, pH and ionic strength were determined as the effective parameters on the swelling behavior of PEGMA-VI microspheres. In the second part of the study, Cu(II) ions were used as a model species in order to investigate the usability of the obtained PEGMA-VI microspheres in heavy metal removal. Adsorption capacities under optimum conditions were determined. The Cu(II) ion adsorption capacity increased by increasing the initial Cu(II) ion concentration, and it reached the maximum value (i.e., 30 mg Cu(II)/g PEGMA-VI microspheres) at 400 mg Cu(II)/L initial Cu(II) ion concentration under the determined optimum conditions. Microspheres were found to be reusable after desorption for several times.


Assuntos
Metais Pesados/isolamento & purificação , Polietilenoglicóis/química , Polivinil/química , Adsorção , Microesferas
4.
J Hazard Mater ; 155(1-2): 114-20, 2008 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-18164127

RESUMO

Poly(vinyl pyridine-poly ethylene glycol methacrylate-ethylene glycol dimethacrylate) [poly(VP-PEGMA-EGDMA)] beads with an average size of 30-100 microm were prepared by suspension polymerization. Poly(VP-PEGMA-EGDMA) beads were characterized by swelling studies, scanning electron microscopy (SEM), elemental analysis, Fourier Transform Infrared Spectroscopy (FTIR). The beads with a swelling ratio of 65% were used for the heavy metal removal studies. Chelation capacity of the beads for the selected metal ions, i.e., Pb(II), Cd(II), Cr(III) and Cu(II) were investigated in aqueous media containing different amounts of these ions (5-80 mg/l) and at different pH values (2.0-10.0). The maximum chelation capacities of the poly(VP-PEGMA-EGDMA) beads were 18.23 mg/g for Pb(II), 16.50 mg/g for Cd(II), 17.38 mg/g for Cr(III) and 18.25 mg/g for Cu(II). The affinity order on mass basis was observed as follows: Cu(II)>Pb(II)>Cr(III)>Cd(II). pH significantly affected the chelation capacity of VP incorporated beads. Heavy metal adsorption on the poly(PEGMA-EGDMA) control microspheres was negligible. Regeneration of the chelating beads was easily performed with 0.1 M HNO3. It was shown that these beads can be used effectively for heavy metal removal from aqueous solutions with repeatedly adsorption-desorption operations. These features show that poly(VP-PEGMA-EGDMA) beads are potential candidate sorbent for heavy metal removal.


Assuntos
Metais Pesados/química , Metacrilatos/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Adsorção , Concentração de Íons de Hidrogênio
5.
Cell Transplant ; 1(6): 391-9, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1344312

RESUMO

Polyhydroxyethylmethacrylate (PHEMA) based microcarriers with different bulk structures were prepared by a phase inversion polymerization technique. PHEMA surfaces were further modified chemically by glow-discharge treatment, and biologically by covalent attachment of fibrinogen and collagen. Hepatocytes were isolated from young male Wistar rats using an in situ portal vein collagenase perfusion technique. Freshly isolated hepatocytes were seeded at 6 x 10(5) cells/mL and microcarrier concentration was 10 g/L. Stationary microcarrier cultures were carried out in standard (nontissue culture) polystyrene petri dishes in a humidified 5% CO2 incubator at 37 +/- 0.5 degrees C. Cell attachment was followed by light microscopy by taking samples from the culture medium every 30 min. Urea and protein syntheses by microcarrier-attached hepatocytes were determined by standard techniques. Nonswellable (highly cross-linked) hydrophilic PHEMA microcarriers did not support cell attachment and viability. However, swellable (low cross-linked) PHEMA microcarriers (pretreated in FBS) allowed high attachment and cell spreading. PHEMA microcarriers treated in dimethylaminoethylmethacrylate (DMAEMA) glow-discharge plasma also improved the cell attachment characteristics of the PHEMA microcarriers. The highest attachment efficiencies (immobilization yields) were observed with the biologically modified PHEMA microcarriers, especially modified with fibronectin. Metabolic activity, as estimated by urea and protein syntheses, was also higher in these microcarriers.


Assuntos
Fígado/citologia , Poli-Hidroxietil Metacrilato , Animais , Materiais Biocompatíveis , Adesão Celular , Colágeno , Técnicas de Cultura/métodos , Fígado/metabolismo , Masculino , Microscopia Eletrônica de Varredura , Perfusão , Veia Porta , Biossíntese de Proteínas , Ratos , Ratos Wistar , Ureia/metabolismo
6.
J Control Release ; 76(3): 265-74, 2001 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-11578741

RESUMO

A random oligomer of N-isopropylacrylamide (NIPAAm) and acrylic acid (AAc) with a AAc content of 3.1+/-0.19 mmol carboxylic acid groups per gram of the oligomer and with a number average molecular weight of 1400 was synthesised by a free radical polymerisation using AIBN in DMF. Then, mono-, di-, and tri-peptide conjugates of this oligomer were prepared by using carboxyl-ends-protected (with methyl ester hydrochloride) forms of alanine, glycine and serine, with a water-soluble carbodiimide. 95, 93, and 31% of the carboxylic acids were conjugated (loaded) at the first step (mono-peptides) with glycine, alanine and serine, respectively. At the second step, percentage of the conjugation of carboxylic acid groups with glycine, alanine and serine were between 99 and 80, 68 and 100, and 21 and 58%, respectively, while the third amino acids were attached to only 21-64% of the carboxylic acids available on the conjugate chains. A decrease was observed in the lower critical solution temperatures (LCSTs) of the amino acid conjugates at pH 4.0 compared with the unconjugated oligomer, which has LCST at 37.7 degrees C at the same pH. LCSTs of di- and tri-peptide conjugates at pH 4.0 were in the range of 38.4-43.3 degrees C, and 42.6-50.8 degrees C, respectively. At pH 7.4, LCSTs of the mono- and di-peptide conjugates were observed in the range of 41.6-43.9 degrees C, and 46.2-60.2 degrees C, respectively, while the co-oligomer at pH 7.4 did not show a LCST up to 60 degrees C. Tri-peptide conjugates did not display LCST at pH 7.4, except the one with glycine-alanine-serine sequence.


Assuntos
Acrilamidas/química , Acrilatos/química , Alanina/química , Glicina/química , Oligopeptídeos/química , Algoritmos , Concentração de Íons de Hidrogênio , Hidrólise , Espectroscopia de Ressonância Magnética , Peso Molecular , Temperatura
7.
J Environ Pathol Toxicol Oncol ; 15(2-4): 115-27, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-9216794

RESUMO

Gas phase pollutants and major ions were measured in the Sarýalan region of Uludag Mountain, which is experiencing severe deforestation. Short- and long-term trends in the concentration of the gas pollutants were computed from the samples obtained in order to identify the source of these pollutants. The higher concentration of O3 during summer months was consistent with the higher photochemical production from precursor gases (NOx) with increased solar flux. The diurnal pattern of O3, NO, NO2 and TSP describes a photochemical smog scenario. A lower pH in aerosols associated with high levels of SO4(2-) and NO3- is an indication of acid deposition. Wind sector analysis revealed that the major contributing source regions are north and south of the sampling site, that is, the city of Bursa, local industries, and the Orhaneli power plant.


Assuntos
Poluentes Atmosféricos/análise , Gases/análise , Humanos , Óxido Nítrico/análise , Nitritos/análise , Dióxido de Nitrogênio , Ozônio/análise , Dióxido de Enxofre/análise , Turquia
8.
Nucl Med Commun ; 12(6): 539-44, 1991 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-1866106

RESUMO

99Tcm-latex particles (LP) is a newly developed radiopharmaceutical for the evaluation of the gastrointestinal (GI) tract. Following oral ingestion, it passes through the entire GI tract undissolved. The purpose of the present investigation was to introduce the clinical application of 99Tcm-LP. A group of 11 healthy volunteers was studied. Following a 12 h fast, the subjects were given 150 ml of water containing 37 MBq of 99Tcm-LP orally. Dynamic images up to 2 h were recorded to document temporal progression of radioactivity. Static images of the abdomen and whole body were taken at intervals. In normal subjects the tracer arrival times at the caecum and sigmoid colon were 3.2 +/- 0.9 and 11.2 +/- 3.2 h, respectively. The average t1/2 value for gastric emptying, 50% colonic filling and small bowel transit time were found to be 21.6 +/- 5.6, 233 +/- 72 and 211 +/- 66.4 min, respectively. In conclusion, 99Tcm-LP has the potential of providing functional information of the GI tract.


Assuntos
Sistema Digestório/diagnóstico por imagem , Tecnécio , Adulto , Fenômenos Fisiológicos do Sistema Digestório , Feminino , Trânsito Gastrointestinal/fisiologia , Humanos , Látex , Masculino , Microesferas , Pessoa de Meia-Idade , Cintilografia , Valores de Referência
9.
Sci Total Environ ; 281(1-3): 205-15, 2001 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-11778952

RESUMO

The concentrations of sulfur dioxide (SO2), ammonia (NH3) and particulate matter were measured for a 6-month period and the concentration of gas phase nitric acid (HNO3) was measured for a 1-month period in the North-eastern Mediterranean atmosphere (Küçük Calticak, Antalya) using a 'filter pack' system that was developed and optimised in our laboratory. Among all the gas phase pollutants, HNO3 had the lowest concentration (0.42 microg m(-3)) followed by ammonia. Most of the measured parameters showed variation in time depending on strengths of source regions and meteorological conditions. Nitric acid is found mostly in particulate form, but gas to particulate partitioning of SO2 shows seasonal variation. Wind trajectory analyses indicate that the major contribution to the observed concentrations come mostly from Eastern Europe and Blacksea regions as well as the southern sector.

10.
Sci Total Environ ; 329(1-3): 43-60, 2004 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-15262157

RESUMO

Lichen samples from different parts of the world have been known to accumulate elements to a greater degree than higher plants, if they are exposed to these elements from the atmosphere or from water and sediments. It has been hypothesized that lichens can be used to monitor air pollution around point and area emission sources. Local variation (variation in substrate, age and morphology of lichen samples) of element concentrations would not be large enough to affect the concentration patterns in large areas. We tested this hypothesis in the Aegean region of Turkey, which is very urbanized and industrialized. No such study has been conducted before in this part of the country. A total of 234 samples of the lichen Xanthoria parietina were collected from a 51,800-km2 area. Samples were washed and analyzed by INAA and ICP-AES for 35 elements. The range of the concentrations for most of the elements on a local scale was an order of magnitude lower than for the element concentrations on a regional scale. The mean local coefficient of variance (CV) was found to be 15, providing that the local variation did not affect the concentration of elements in the sampling region. According to cluster analysis, 8 (As, Hg, Pb, Sb, Fe, Mn, Na and K) elements are indicative of important local pollution locations and their zone of impact in the region. By mapping the concentrations of eight indicative elements in lichen Xanthoria parietina of the Aegean region, it was possible to relate deposition to the existence of known sources of pollution in certain areas. Location of pollution sources such as iron-steel plants, and coal burning in the cities, industrial activity and two important coal-fired power plants generally corresponded with locations of highest element accumulations in the lichens.


Assuntos
Poluentes Atmosféricos/análise , Líquens/química , Metais Pesados/análise , Carvão Mineral , Monitoramento Ambiental/métodos , Incineração , Indústrias , Centrais Elétricas , Turquia
11.
Mikrobiyol Bul ; 26(4): 359-66, 1992 Oct.
Artigo em Turco | MEDLINE | ID: mdl-1331720

RESUMO

In this study, the distributions of Anti-HSV 1 and HSV 2 IgG and IgM antibodies have been investigated in sera obtained from 296 pregnant women who were admitted to the gynecology clinics of Medical Faculty of Atatürk University, Erzurum, Turkey. While the 24 (8.11%) of 287 HSV 1 IgG antibody positive patients were IgM positive but Anti-HSV 1 IgM alone was not detected in any patients. On the other hand, in 16 (5.41%) of 125 (42.23%) patients who were Anti-HSV 2 IgG antibody positive, HSV 2 IgM antibodies were detected too. In the 4 patients (1.35%), HSV 2 IgM antibodies were detected alone.


Assuntos
Anticorpos Antivirais/sangue , Herpes Simples/imunologia , Complicações Infecciosas na Gravidez/imunologia , Simplexvirus/imunologia , Adulto , Fatores Etários , Feminino , Herpes Simples/epidemiologia , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Gravidez , Complicações Infecciosas na Gravidez/epidemiologia , Turquia/epidemiologia
12.
Indian J Pediatr ; 77(4): 407-11, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20422324

RESUMO

OBJECTIVE: The present study assessed whether there is a correlation between hepatic artery resistive index (HARI) and increase of body mass index and hepatosteatosis grading in children with non-alcoholic fatty liver disease (NAFLD) reflecting hemodynamic effects of hepatosteatosis. METHODS: Thirty three healthy children [body mass index(BMI): mean+/- standart deviation(SD), min-max: 20.1+/-1.14(18.5-23.7), 33 overweight [BMI:25.1+/-2.2 (18.5-23.7)] and 66 obese [BMI:31.1+/-2(25.6-40)] adolescents were enrolled into the study. To search the relation of HARI with fatty liver degree, study subjects subdivided into groups according to their degree of fatty liver at ultrasonography(US). RESULTS: Increase of HARI was correlated with increase in BMI (p<0.0001, r=0.533). Increase of HARI was well correlated with increase in degree of fatty liver (p<0.0001, r=0.630). CONCLUSION: The present study results suggest that there are positive correlations of HARI with BMI and hepatosteatosis grade in obese children with NAFLD. HARI may be a candidate parameter to determine early alarming hemodynamic changes in hepatic tissue of obese children with fatty liver before development of severe stages NAFLD.


Assuntos
Fígado Gorduroso/fisiopatologia , Artéria Hepática/fisiopatologia , Obesidade/fisiopatologia , Resistência Vascular , Adolescente , Índice de Massa Corporal , Criança , Fígado Gorduroso/complicações , Feminino , Humanos , Masculino , Obesidade/complicações , Ultrassonografia Doppler
13.
Anal Bioanal Chem ; 386(5): 1303-12, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17019572

RESUMO

A newly designed glass-PDMS microchip-based sensor for use in the determination of Ca(2+) ions has been developed, utilizing reflectance measurements from arsenazo III (1,8-dihydroxynaphthalene-3,6-disulfonic acid-2,7-bis[(azo-2)-phenyl arsenic acid]) immobilized on the surface of polymer beads. The beads, produced from cross-linked poly(p-chloromethylstyrene) (PCMS), were covalently modified with polyethylenimine (PEI) to which the Arsenazo III could be adsorbed. The maximum amount of Arsenazo III which could be immobilized onto the PEI-attached PCMS beads was found to be 373.71 mg g(-1) polymer at pH 1. Once fabricated, the beads were utilized at the detection point of the microfluidic sensor device with a fiber optic assembly for reflectance measurements. Samples were mobilized past the detection point in the sensor where they interact with the immobilized dye. The sensor could be regenerated and re-used by rinsing with HCl solution. The pH, voltage, linear range, and the effect of interfering ions were evaluated for Ca(2+) determination using this microchip sensor. At the optimum potential, 0.8 kV, and pH 9.0, the linear range of the microchip sensor was 3.57 x 10(-5) - 5.71 x 10(-4) M Ca(2+), with a limit of detection (LOD) of 2.68 x 10(-5) M. The microchip biosensor was then applied for clinical analysis of calcium ions in serum with good results.


Assuntos
Cálcio/análise , Dimetilpolisiloxanos/química , Dispositivos Lab-On-A-Chip , Procedimentos Analíticos em Microchip/métodos , Arsenazo III/química , Desenho de Equipamento , Análise de Falha de Equipamento , Tecnologia de Fibra Óptica , Vidro , Concentração de Íons de Hidrogênio , Fibras Ópticas , Tamanho da Partícula , Polietilenoimina/química , Poliestirenos/química , Reprodutibilidade dos Testes , Propriedades de Superfície , Fatores de Tempo
14.
J Mol Model ; 11(1): 55-60, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15592689

RESUMO

In this paper, we have investigated the lower critical solution temperature (LCST) of N-isopropylacrylamide-acrylic acid (NIPAAm-AAc) copolymer as a function of chain-transfer agent/initiator mole ratio, acrylic acid content of copolymer, concentration, pH and ionic strength of aqueous copolymer solution. Aqueous solutions with the desired properties were prepared from previously purified polymers, synthesized at 65 degrees C by solution polymerization using ethanol. The effects of each parameter on the LCST were examined experimentally. In addition, an artificial neural network model that is able to predict the lower critical solution temperature was developed. The predictions from this model compare well against both training and test data sets with an average error less than 2.53%.


Assuntos
Acrilamidas/química , Acrilatos/química , Redes Neurais de Computação , Polímeros/química , Modelos Moleculares , Transição de Fase , Solubilidade , Soluções , Temperatura
15.
J Environ Monit ; 3(6): 661-5, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11785642

RESUMO

Gas phase pollutants. nitric acid (HNO3), sulfur dioxide (SO2), ammonia (NH3) and particulate matter, were collected simultaneously for six months from the Eastern Mediterranean atmosphere (Küçük Calticak, Antalya) using a "filter pack" system developed in our laboratory. This system is a combination of chemically treated filters for the collection of gaseous ammonia and sulfur dioxide. and Teflon and nylon filters for the collection of particulate matter and gaseous nitric acid, respectively. After pre-treatment, Teflon, nylon and the treated filters were analyzed by ion chromatography (IC) for major ionic species: SO4(2-) NO3- and Cl, and by colorimetry for NH4+ ion. Comparison of the SRM (Standard Reference Material) results with measured concentrations showed a good precision for the IC analyses: 3%, 1% and 2% for Cl-, NO3 and SO4(2-) ions. respectively. Most of the measured parameters were log-normally distributed. Chloride ion had the highest (4.30 microg m(-3) and HNO3 had the lowest (0.42 microg m(-3)) concentrations. Total acidity in the Eastern Mediterranean is controlled by 47.7% HNO3 and 52.8% by H2SO4. Ammonium, nss-SO4(2-) (non-sea salt sulfate) and NO3 did not show a strong correlation, (r = 0.4), which means that ammonia is not the major neutralizing species in the Eastern Mediterranean atmosphere.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Amônia/análise , Cromatografia , Filtração , Gases/análise , Região do Mediterrâneo , Ácido Nítrico/análise , Tamanho da Partícula , Valores de Referência , Dióxido de Enxofre/análise
16.
Talanta ; 63(2): 273-7, 2004 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-18969428

RESUMO

Three digestion procedures have been tested on lichen samples for application in the determination of major, minor and trace elements (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, V and Zn) in lichen samples collected in Aegean Region of Turkey by inductively coupled plasma atomic emission spectrometer (ICP-AES). The acid mixture of concentrated HNO(3), H(2)O(2) and HF were used. The instrument was optimized using lichen matrix considering RF power, nebulizer pressure, auxiliary flow rate and pump rate. The accuracy of the overall analyses was first estimated by analysis of two certified reference materials. Good agreement between measured and reference values were found for almost all elements. As the second way of determining the accuracy, results obtained from independent analytical techniques (ICP-AES and instrumental neutron activation analysis (INAA)) were compared for all elements by analyzing real samples. Correlation coefficients of two techniques for the elements ranged between 0.70 (Mg) and 0.96 (Fe). Among the three digestion systems, namely microwave, open vessel and acid bomb, microwave digestion system gave the best recovery results. The method detection limit (MDL) was computed using reagent blanks of microwave digestion system since it provides cleaner sample preparation. Detection limit is adequate for all elements to determine the elements in lichen samples. The precision was assessed from the replicate analyses of reagent blanks of microwave digestion system and was found to be less than 1.5% relative standard deviation (R.S.D.).

17.
Environ Monit Assess ; 33(3): 215-35, 1994 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24201887

RESUMO

Data from continuous measurements of SO2 NO x , suspended particulate matter (SPM) and meteorological parameters at seven sites around a highly industrialized region in the Aegean coast of Turkey, between July 15, 1991 to July 31, 1992 were used to evaluate spatial and temporal variations of air quality parameters. Low annual averages and insignificant differences between day and night concentrations were observed at stations far from sources. At stations close to sources, annual average concentrations were high and diurnal patterns were significant. Annual average SO2 and SPM concentrations in all stations used the 'Krigging' technique to assess the impact of industries on air quality in the surrounding airshed. Results have demonstrated that Turkish air quality standards for SO2 were exceeded in a circle with a radius of 4 km and which was centered on the petrochemical complex and refinery. Similarly, standards for SPM were exceeded in a circle with a radius of 1.2 km and which was centered on the ironwork plants. Both SO2 and SPM showed well defined diurnal variations, particularly in stations close to sources. The SO2 concentrations showed a maximum during day-time, while SPM concentrations peaked after midnight. Although annual average SO2 and SPM concentrations were highly variable depending on distances between stations and sources, background concentrations of the same pollutants, calculated by stripping episodes from data, did not change significantly from one station to another. Long range transport and resuspension of local soil were suggested as sources of background SO2 and SPM, respectively. The difference between observed and background concentrations of SO2 and SPM in each station was related to the impact of industries on air quality at that particular site.

18.
J Microencapsul ; 10(1): 67-76, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8383200

RESUMO

Latex particles coated with either amino or carboxyl groups were labelled with 99mTc. Two labelling methods were used: (1) direct labelling with tin reduction and (2) ligand exchange with tin pyrophosphate. Labelling efficiency and the radiochemical impurities were determined by thin-layer chromatography. Effect of [Sn2+] and pH on labelling yield was investigated to find the optimum labelling conditions. 99mTc-labelled latexes were administered orally to six normal subjects, and scintigrams from the abdomen were obtained at 1, 3, 6, and 24 h. Whole-body scintigrams were also taken by a gamma-camera. The first method was found to be efficient for carboxyl coated latexes and the second method for both types, giving > 98 per cent labelling efficiency. Labelled latexes were stable up to 24 h of testing at RT (> 99 per cent labelled). Scintigraphic studies showed that the labelled particles remained in GIT (98.11 +/- 0.92 per cent at 6 h) without dissociation of the label. No radioactivity was observed in the thyroid, stomach (at late images) and urinary bladder. This study demonstrated that latex particles coated with either amino or carboxyl groups can be efficiently labelled with 99mTc and used in the studies of GI function.


Assuntos
Sistema Digestório/diagnóstico por imagem , Microesferas , Pertecnetato Tc 99m de Sódio , Acrilatos , Adulto , Cromatografia em Camada Fina , Fenômenos Fisiológicos do Sistema Digestório , Humanos , Concentração de Íons de Hidrogênio , Marcação por Isótopo , Látex , Metacrilatos , Tamanho da Partícula , Poliestirenos , Cintilografia , Estanho/farmacologia
19.
Int J Rad Appl Instrum B ; 18(2): 253-8, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-2026503

RESUMO

A new radiopharmaceutical for the study of colon transit time and morphology is proposed. Polymeric latexes, as monodisperse polymeric spheres (1-10 microns in diameter), were prepared by a coaxial dispersion polymerization of styrene and dimethylaminoethyl-methacrylate (DMAEA). They were labelled with 99mTc by the tin reduction method with high efficiency (greater than 99%). The label was stable up to 48 h at pH values of 1-8 at room temperature. Scintigrams obtained in rabbits after oral administration of 37 MBq of 99mTc-latex particles showed that greater than 90% of the dose remained in the gastrointestinal tract. The cumulative faecal excretion was 8.6 +/- 6.7 in 24 h and 21.3 +/- 13.8% in 48 h. In human studies the colon was well visualized at 4 h. The thyroid and the urinary bladder were not detected on scintigrams, indicating the stability of the label in vivo. Our results demonstrated that the radiopharmaceutical developed in the present study was ideal for the intended purpose.


Assuntos
Colo/diagnóstico por imagem , Trânsito Gastrointestinal/fisiologia , Compostos de Organotecnécio , Ácidos Polimetacrílicos , Poliestirenos , Adulto , Animais , Colo/fisiologia , Estabilidade de Medicamentos , Estudos de Avaliação como Assunto , Humanos , Marcação por Isótopo , Coelhos , Cintilografia
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