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1.
Zhonghua Gan Zang Bing Za Zhi ; 30(11): 1207-1210, 2022 Nov 20.
Artículo en Zh | MEDLINE | ID: mdl-36891699

RESUMEN

Objective: Hepatic amyloidosis is a metabolic disease with a low incidence rate. However, because of its insidious onset, the rate of misdiagnosis is high, and it usually progresses to a late stage when it is diagnosed. This article analyzes the clinical features of hepatic amyloidosis by combining clinical pathology in order to improve the clinical diagnosis rate. Methods: Clinical and pathological data of 11 cases of hepatic amyloidosis diagnosed at the China-Japan Friendship Hospital from 2003 to 2017 were summarized and analyzed retrospectively. Results: The clinical manifestations of 11 cases mainly included abdominal discomfort (4/11), hepatomegaly (7/11), splenomegaly (5/11), fatigue (6/11), etc. Biochemical test results showed that most patients' alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, γ-glutamyl transferase, total bilirubin, direct bilirubin, and total bile acids, accompanied by hypoalbuminemia were elevated, while some patients' 24-h urinary protein, creatinine, and blood urea nitrogen were elevated. Conclusion: All patients had slightly elevated aspartate transaminase levels (within 5 times the upper limit of normal), and 72% had slightly elevated alanine transaminase. Alkaline phosphatase and γ-glutamyl transferase levels were significantly raised in all cases, with the highest result for γ-glutamyl transferase being 51 times the upper limit of normal. Damage to the hepatocytes has an effect on the biliary system as well, leading to symptoms such as portal hypertension and hypoalbuminemia [(0.54~0.63) × upper limit of normal value, 9/11]. Amyloid deposits within the artery wall (54.5% of patients) and portal vein (36.4% of patients) were also indicative of vascular injury. A liver biopsy should be recommended for patients with unexplained elevated transaminases, bile duct enzymes, and portal hypertension in order to establish a definitive diagnosis.


Asunto(s)
Amiloidosis , Hipertensión Portal , Hipoalbuminemia , Enfermedades Metabólicas , Humanos , Fosfatasa Alcalina , Estudios Retrospectivos , Bilirrubina , Alanina Transaminasa , gamma-Glutamiltransferasa , Amiloidosis/diagnóstico
2.
Niger J Clin Pract ; 25(12): 1955-1962, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36537450

RESUMEN

Background and Aim: Four premolars extractions are routine procedures for correction of malocclusion, but will inevitably lead to a reduction of tongue space, whether this will weaken the pharyngeal airway remains a controversy. Patients and Methods: Cone-beam computed tomography (CBCT) radiographs of 80 patients who completed four premolar extraction orthodontic treatments were collected and divided into three anteroposterior skeletal groups according to the ANB (angle subspinale to nasion to supramentale) value. Linear, angular, cross-sectional area, and volumetric dimensions of the pharyngeal airway were measured using Dolphin Imaging 11.9 software. One-way analysis of variance and Pearson's correlation coefficient test were performed to assess the intergroup comparisons. Treatment changes were evaluated with two-sample t-tests. Results: In intergroup comparisons, vertical linear and cross-sectional area differences were identified in S-Go/N-Me, VD1, VD1/N-Me, VD2/N-Me, AA, OAA and OMINI (p<0.05), while other measurements showed no significant differences. Angle2, the tilting degree of the pharyngeal airway, showed a positive correlation with ANB (p<0.05). As for the treatment changes, a significant increase was found in the pharyngeal airway in the Class I group (OUA p<0.05, VD1 p<0.001, VD2 p<0.05) and Class II group (VD1 p<0.001. VD2, p<0.05), and inversely, a significant decrease was found in the pharyngeal airway in the Class III group (OAA p<0.05, OMINI p<0.05, OUA p<0.05). No volumetric difference was identified. Interestingly, regarding the preoperative pharyngeal airway size, values trended to the mean value significantly. Conclusion: Four premolar extraction orthodontic treatments did not affect the pharyngeal airway volume except for the vertical liner and cross-sectional area dimensions. The trend of the gold standard suggested a positive influence of four premolar extraction orthodontic treatments.


Asunto(s)
Maloclusión de Angle Clase III , Maloclusión , Tomografía Computarizada de Haz Cónico Espiral , Humanos , Diente Premolar/cirugía , Mandíbula , Faringe , Tomografía Computarizada de Haz Cónico/métodos , Cefalometría/métodos , Imagenología Tridimensional/métodos
3.
Ann Oncol ; 29(1): 230-236, 2018 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-29361134

RESUMEN

Background: Targeted capture sequencing can potentially facilitate precision medicine, but the feasibility of this approach in gastrointestinal (GI) malignancies is unknown. Patients and methods: The FOrMAT (Feasibility of a Molecular Characterisation Approach to Treatment) study was a feasibility study enrolling patients with advanced GI malignancies from February 2014 to November 2015. Targeted capture sequencing (mainly using archival formalin-fixed paraffin-embedded diagnostic/resection samples) was carried out to detect mutations, copy number variations and translocations in up to 46 genes which had prognostic/predictive significance or were targets in current/upcoming clinical trials. Results: Of the 222 patients recruited, 215 patients (96.8%) had available tissue samples, 125 patients (56.3%) had ≥16 genes successfully sequenced and 136 patients (61.2%) had ≥1 genes successfully sequenced. Sample characteristics influenced the proportion of successfully sequenced samples, e.g. tumour type (colorectal 70.9%, biliary 52.6%, oesophagogastric 50.7%, pancreas 27.3%, P = 0.002), tumour cellularity (high versus low: 78.3% versus 13.3%, P ≤ 0.001), tumour content (high versus low: 78.6% versus 27.3%, P = 0.001) and type of sample (resection versus biopsy: 82.4% versus 47.6%, P ≤ 0.001). Currently, actionable alterations were detected in 90 (40.5%) of the 222 patients recruited (66% of the 136 patients sequenced) and 2 patients subsequently received a targeted therapy. The most frequently detected currently actionable alterations were mutations in KRAS, BRAF, TP53 and PIK3CA. For the 205 patients with archival samples, the median time to obtain sequencing results was 18.9 weeks, including a median of 4.9 weeks for sample retrieval and 5.1 weeks for sequencing. Conclusions: Targeted sequencing detected actionable alterations in formalin-fixed paraffin-embedded samples, but tissue characteristics are of critical importance in determining sequencing success. Routine molecular profiling of GI tumours outside of clinical trials is not an effective use of healthcare resources unless more targeted drugs become available. ClinicalTrials.gov identifier: NCT02112357.


Asunto(s)
Análisis Mutacional de ADN/métodos , Neoplasias Gastrointestinales/genética , Mutación , Análisis de Secuencia de ADN/métodos , ADN de Neoplasias/química , ADN de Neoplasias/genética , Estudios de Factibilidad , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Humanos
4.
J Cell Biol ; 107(6 Pt 1): 2149-61, 1988 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-2974039

RESUMEN

We have examined the fate of newly synthesized T cell antigen receptor (TCR) subunits in a T cell hybridoma deficient in expression of the clonotypic beta chain. Synthesis and assembly of the remaining chains proceed normally but surface expression of TCR chains is undetectable in these cells. A variety of biochemical and morphological techniques has been used to show that the TCR chains in these cells fail to be transported to any of the Golgi cisternae. Instead, they are retained in a pre-Golgi compartment which is either part of or closely related to the endoplasmic reticulum. The CD3-delta chain is degraded by a non-lysosomal process that is inhibited at temperatures at or below 27 degrees C. By contrast, the remaining chains (CD3-epsilon, CD3-gamma, and zeta) are very stable over 7 h. We propose possible mechanisms that may explain the differential fate of TCR chains retained in a pre-Golgi compartment.


Asunto(s)
Retículo Endoplásmico/metabolismo , Receptores de Antígenos de Linfocitos T/metabolismo , Linfocitos T/metabolismo , Animales , Antígenos de Diferenciación de Linfocitos T/metabolismo , Transporte Biológico , Complejo CD3 , Compartimento Celular , Aparato de Golgi/metabolismo , Hibridomas , Lisosomas/efectos de los fármacos , Sustancias Macromoleculares , Ratones , Microscopía Electrónica , Receptores de Antígenos de Linfocitos T/ultraestructura , Relación Estructura-Actividad , Temperatura
5.
J Cell Biol ; 120(5): 1123-35, 1993 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8436587

RESUMEN

Protein localization to the TGN was investigated by examining the subcellular distribution of chimeric proteins in which the cytoplasmic and/or transmembrane domains of the TGN protein, TGN38, were substituted for the analogous domains of the plasma membrane protein, Tac. Using immunofluorescence and immunoelectron microscopy, the COOH-terminal cytoplasmic domain of TGN38 was found to be sufficient for localization of the chimeric proteins to the TGN. Deletion analysis identified an 11-amino acid segment containing the critical sequence, YQRL, as being sufficient for TGN localization. TGN localization was abrogated by mutation of the tyrosine or leucine residues in this sequence to alanine, or of the arginine residue to aspartate. In addition to specifying TGN localization, the 11-amino acid segment was active as an internalization signal, although the property of internalization alone was insufficient to confer TGN localization. Overexpression of chimeric proteins containing TGN localization determinants resulted in their detection at the plasma membrane and in intracellular vesicles, and abolished detection of endogenous TGN38. These results suggest that discrete cytoplasmic determinants can mediate protein localization to the TGN, and reveal a novel role for tyrosine-based motifs in this process.


Asunto(s)
Glicoproteínas , Aparato de Golgi/química , Glicoproteínas de Membrana/metabolismo , Proteínas de la Membrana , Secuencia de Aminoácidos , Animales , Compartimento Celular , Chlorocebus aethiops , Citoplasma/metabolismo , Técnica del Anticuerpo Fluorescente , Glicoproteínas de Membrana/inmunología , Datos de Secuencia Molecular , Ratas , Proteínas Recombinantes de Fusión/metabolismo , Relación Estructura-Actividad , Transfección
6.
Science ; 154(3745): 124-30, 1966 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-17740097

RESUMEN

It appears possible to extend the application of most of the existing detection techniques to the identification and separation of charged particles in the relativistic energy region.One can probably extend these applications, in certain limited cases, up to an energy region of several hundred billion electron volts. However, for general applications in the identification of particles in the ultrarelativistic region, the existing detectors are rather limited, and new methods and approaches are desirable. At present, detectors making use of the relativistic rise effect seem to show considerable promise.

7.
J Histochem Cytochem ; 23(5): 359-68, 1975 May.
Artículo en Inglés | MEDLINE | ID: mdl-805170

RESUMEN

Microperoxisomes were identified in the franulosa lutein cells from the corpora lutea of rhesus monkeys (Macaca mulatta). These organelles were histochemically visualized in aldehyde-fixed tissues icubated in alkaline 3,3'-diaminobenzidine (DAB). The DAB staining of the microperoxisomes was abolished when the tissues were preincubated in specific inhibitors for catalse or when the H2O2 was omitted from the DAB medium. Microperoxisomes were differentiated from primary lysosmes by the Gomori acid phosphatase staining. Tortuous undulating agranular endoplasmic reticulum (ER) was usually closely associated with microperoxisomes. Those regions of the granular ER which were closely associated with microperoxosomes lacked ribsomes. Micropersoxisomes were often contiguous with lipid droplets, and in some instances the limiting membrane of the moroperosisomes appeared discontinous at the point of contiguity, and the DAB staining substance diffused onto the surface of the lipid droplet. In these instances, the adjacent area of the lipid droplet showed electron-lucent staining.


Asunto(s)
Fosfatasa Ácida/metabolismo , Cuerpo Lúteo/ultraestructura , Microcuerpos/metabolismo , Organoides/metabolismo , 3,3'-Diaminobencidina , Animales , Femenino , Células de la Granulosa/ultraestructura , Haplorrinos , Histocitoquímica , Macaca mulatta , Microscopía Electrónica , Embarazo
8.
J Reprod Immunol ; 4(2): 91-106, 1982 May.
Artículo en Inglés | MEDLINE | ID: mdl-7050377

RESUMEN

Monoclonal anti-mouse sperm antibodies have been produced by fusing mouse myeloma cells with spleen cells from rats immunized with epididymal sperm of C3H mice, Immunoprecipitation and immunoperoxidase techniques showed that one such monoclonal antibody, AMS IV-33, recognized a 200 000 dalton protein localized on the acrosomal cap of the sperm cell. Two other monoclonal antibodies AMS IV-54 and -76, reacted with a 68 000 dalton component on the surface of the sperm tail. Both antigenic targets were species specific and were present in about equal amounts on sperm from several different strains of mice. The tail protein was sperm specific, whereas the antibody reacting with the acrosomal cap protein also appeared to react somewhat with antigens present in other mouse tissues.


Asunto(s)
Anticuerpos Monoclonales/inmunología , Antígenos de Superficie , Espermatozoides/inmunología , Acrosoma/inmunología , Animales , Sitios de Unión de Anticuerpos , Precipitación Química , Cricetinae , Electroforesis en Gel de Poliacrilamida , Femenino , Cobayas , Humanos , Técnicas para Inmunoenzimas , Masculino , Mesocricetus , Ratones , Ratones Endogámicos C3H , Ratones Endogámicos C57BL , Peso Molecular , Ratas , Ratas Endogámicas , Especificidad de la Especie , Cola del Espermatozoide/inmunología
9.
Fertil Steril ; 37(2): 249-57, 1982 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-7037466

RESUMEN

Surface antigens of mammalian sperm were studied by use of monoclonal antibodies (MAs). Six hybridoma cell lines were obtained by fusion of mouse myeloma cells with spleen cells from rats immunized with unwashed, epididymal sperm from C3H mice. Quantitative assessment of antibody binding, using a solid phase, antibody-protein A assay, indicated that four MAs bound to integral, sperm surface antigens; two others bound to nonintegral sperm antigens or epididymal fluid components. Immunofluorescence studies showed specific binding of individual MAs to localized regions: acrosome, midpiece, and midpiece and tail. All of these MAs inhibited sperm-egg binding, and those to the midpiece and/or tail immobilized sperm cells. The monoclonal antibodies provide probes for immunochemical characterization of sperm antigens and for elucidation of the role of the antigens in sperm.


Asunto(s)
Anticuerpos Monoclonales/biosíntesis , Antígenos de Superficie/análisis , Hibridomas/inmunología , Espermatozoides/inmunología , Animales , Sitios de Unión de Anticuerpos , Fusión Celular , Cricetinae , Femenino , Cobayas , Técnicas Inmunológicas , Masculino , Mesocricetus , Ratones , Ratones Endogámicos C3H , Ratas , Ratas Endogámicas
10.
Steroids ; 35(1): 43-51, 1980 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-6246660

RESUMEN

In an attempt to justify use of trypsin to achieve more thorough dispersion of luteal cell clumps in vitro, progesterone (P) production by collagenase dispersed monkey luteal cells from the mid-luteal phase corpus luteum (CL) was examined in vitro either after 10 min, or continuous (3h) exposure to trypsin (TR). In the first experiment, cells were pre-incubated in TR, then incubated at 37 degrees C for 3h with human chorionic gonadotropin (hCG) after the addition of soybean-trypsin inhibitor (STI). Pre-incubation of luteal cells with TR had no effect on the level of P production under basal conditions. Cells that were preincubated with TR responded to hCG stimulation with increased progesterone secretion (P less than 0.01) in a fashion similar to untreated cells. P production in response to hCG was independent of TR concentration over the range of 0.05% to 0.2% during the pre-incubation period. However, continuous exposure (3h) of cells to TR significantly depressed (P less than 0.01) basal P secretion and inhibited the response to hCG. We conclude that TR had no effect on the biopotency of hCG per se, but probably the over-exposure to TR had an adverse effect on the LH/hCG receptors. Addition of STI after a 10 min pre-incubation with TR, prevented these deliterious effects, thereby permitting the use of TR to improve the completeness of luteal cell dissociation.


Asunto(s)
Cuerpo Lúteo/metabolismo , Progesterona/biosíntesis , Tripsina/farmacología , Animales , Gonadotropina Coriónica/metabolismo , Cuerpo Lúteo/efectos de los fármacos , Femenino , Haplorrinos , Técnicas In Vitro , Cinética , Hormona Luteinizante/metabolismo , Macaca mulatta , Receptores de Superficie Celular/metabolismo
11.
Int J Pharm ; 179(2): 257-65, 1999 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-10053218

RESUMEN

Degradation kinetics of cyclic HPMPC (cHPMPC), 1-[((S)-2-hydroxy-2-oxo-1,4,2-dioxaphosphorinan-5-yl)methyl]cytosi ne, and its parent compound cidofovir (also known as HPMPC) were conducted in the pH range of 2-11 at 70 degrees C. cHPMPC manifested greater chemical stability than cidofovir, except under alkaline conditions (pH?9). Three degradation products-cidofovir, cyclic HPMPU and HPMPU-were identified for cHPMPC, and the product distribution was characterized via a stability-indicating HPLC assay. Cyclic HPMPU and HPMPU are the uracil analogs of cHPMPC and cidofovir, respectively, formed through a hydrolytic deamination pathway. The deamination and hydrolysis rate constants for cHPMPC under acidic conditions were derived from the degradation product curves. The deamination rate constants for cHPMPC were about 8-fold slower compared to that for cidofovir. The enhanced chemical stability for cHPMPC relative to cidofovir is attributed to the absence of intramolecular catalysis with cHPMPC.


Asunto(s)
Antivirales/química , Citosina/análogos & derivados , Organofosfonatos , Compuestos Organofosforados/química , Profármacos/química , Cidofovir , Citosina/química , Estabilidad de Medicamentos , Hidrólisis , Cinética , Solubilidad
12.
Am J Health Syst Pharm ; 53(16): 1939-43, 1996 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-8862207

RESUMEN

The stability of cidofovir in i.v. admixtures under refrigerator and room temperature conditions was studied. Admixtures of cidofovir 0.21 and 8.12 mg/mL in 0.9% sodium chloride injection or 5% dextrose injection and of 0.085 and 3.51 mg/mL in 5% dextrose and 0.45% sodium chloride injection were prepared in triplicate in polyvinyl chloride (PVC) or polyethylene-polypropylene containers and i.v. administration sets and stored for 24 hours at 2-8 or 30 degrees C. The lower concentration of cidofovir corresponded to an assumed dose of 0.5 mg/kg for a 40-kg patient, and the higher concentration to an assumed dose of 10 mg/kg for a 100-kg patient. Samples were removed at 0 and 24 hours and analyzed for cidofovir concentration by high-performance liquid chromatography. Physical compatibility was also studied. The stability of cidofovir in 0.9% sodium chloride injection and in 5% dextrose injection at low- and high-dose concentrations was unaffected by storage at either temperature. All admixtures were clear, colorless, and free of visible particles or precipitation. There were no substantial changes in pH or number of particles of > or = 10 microns in diameter. Cidofovir 0.21 and 0.12 mg/mL was stable in 0.9% sodium chloride injection and 5% dextrose injection in PVC and polyethylene-polypropylene containers and i.v. administration sets for up to 24 hours at 2-8 and 30 degrees C. Cidofovir was compatible with the injectable solutions studied.


Asunto(s)
Antivirales/química , Citosina/análogos & derivados , Organofosfonatos , Compuestos Organofosforados/química , Cromatografía Líquida de Alta Presión , Cidofovir , Citosina/química , Estabilidad de Medicamentos , Glucosa , Concentración de Iones de Hidrógeno , Inyecciones , Concentración Osmolar , Tamaño de la Partícula , Cloruro de Polivinilo , Cloruro de Sodio , Factores de Tiempo
13.
Artículo en Inglés | MEDLINE | ID: mdl-11563007

RESUMEN

The decomposition kinetics of bis-POC PMEA and bis-POC PMPA followed pseudo-first order kinetics with the corresponding mono-POC ester detected as the only observable degradation product for all the pH values studied. The rates of hydrolysis of bis-POC PMEA over the pH range studied was described by [formula: see text] The 18O incorporation studies revealed that hydrolysis of bis-POC PMEA at pH 7.0 primarily proceeds via P-O cleavage with an additional minor pathway involving C-O bond cleavage. Hydrolysis of bis-POC PMPA was found to be about 2 fold slower than bis-POC PMEA at pH values above 6.0.


Asunto(s)
Adenina/análogos & derivados , Adenina/química , Antivirales/química , Organofosfonatos , Compuestos Organofosforados/química , Profármacos/química , Estabilidad de Medicamentos , Concentración de Iones de Hidrógeno , Cinética , Soluciones , Tenofovir
14.
PDA J Pharm Sci Technol ; 51(1): 30-5, 1997.
Artículo en Inglés | MEDLINE | ID: mdl-9099062

RESUMEN

The antiviral drug 9-[2-(phosphonomethoxy)ethyl]adenine, PMEA, was developed as an intravenous product for the treatment of human immunodeficiency virus infection. During the course of stability monitoring, PMEA i.v. injection was found to undergo particulate matter formation under extended storage at ambient temperature. Isolation and characterization of the particulates revealed them to be metal ion-PMEA complexes. The principle metal ions associated with the particulates were iron and zinc, present as trace impurities (< or = 40 ppm) in PMEA drug substance determined by inductively coupled argon plasma spectroscopy. These visible particles are characterized by energy-dispersive x-ray spectrometry and fourier transform infrared spectroscopy. This study describes the systematic evaluation of the observed solution phenomena and details alternative formulation systems to eliminate particulate formation in the PMEA injectable product.


Asunto(s)
Adenina/análogos & derivados , Antivirales/química , Organofosfonatos , Adenina/química , Estabilidad de Medicamentos , Hierro/análisis , Soluciones , Zinc/análisis
15.
J Exp Zool ; 233(2): 269-76, 1985 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-4038732

RESUMEN

Mouse oocytes were treated with 8% ethanol for 3-6 min. The rate and pathways of parthenogenetic activation, occurrence of cortical reaction, and zona solubility changes were assessed in alcohol-treated eggs. The incidence of parthenogenetic activation was greatest (91%) after 3-4-min exposure, and it was reduced (84%) after 5-6-min exposure to alcohol. Also, the rate of haploid single pronucleate parthenogenones decreased and the rate of fragmented ova increased with increase time of exposure to ethanol. Ultrastructural observations showed occurrence of cortical reaction, disappearance and subsequent reappearance of short microvilli. A slight damage occurred to the ER in alcohol-exposed ova. The zona dissolution assay utilizing alpha-chymotrypsin demonstrated decreased solubility of the zonae pellucidae after exposure to alcohol. The zona dissolution t50 increased from 0.5-2.5 min in nontreated unfertilized oocytes to about 4 h in activated ova. The t50 of in vivo fertilized eggs was 4 1/2 h. Empty zonae exposed to alcohol lysed at the same rate as nontreated control zonae did. The results indicate that activation of mouse oocytes with alcohol initiates completion of meiosis and triggers the cortical reaction, which results in subsequent hardening of the zona pellucida.


Asunto(s)
Etanol/farmacología , Oocitos/efectos de los fármacos , Óvulo/efectos de los fármacos , Zona Pelúcida/efectos de los fármacos , Animales , Femenino , Meiosis , Ratones , Ratones Endogámicos , Oocitos/ultraestructura , Partenogénesis/efectos de los fármacos , Factores de Tiempo
16.
Anat Rec ; 201(2): 273-81, 1981 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7032363

RESUMEN

An improved method is presented for processing single cells for electron microscopy. Agarose, which has a low (30 degrees C) gelling temperature, was used as an initial embedding medium for single cells (spermatozoa and oocytes) and dissociated cell preparations (luteal cells and spleen cells). Dispersed cells of corpus luteum, spleen, and epididymal spermatozoa were placed in 1.5% agarose after aldehyde fixation. These fixed cells, embedded in agarose, were packed into a dense pellet by centrifugation, postfixed, then embedded in Epon. Mammalian eggs were not centrifuged; instead, they were embedded in agarose discs. Cells embedded in agarose were cooled below 30 degrees C to allow for gelling, then processed for electron microscopy. Because agarose has a low gelling temperature, some heat-labile substances were preserved, as demonstrated by retention of peroxidase activity using the DAB histochemical method. The agarose embedding procedure is both rapid and facile, and has proven to be of value in the handling of fragile single cells for electron microscopic studies.


Asunto(s)
Células Cultivadas/ultraestructura , Técnicas Citológicas , Polisacáridos , Sefarosa , Animales , Cuerpo Lúteo/citología , Cricetinae , Femenino , Macaca mulatta , Masculino , Ratones , Microscopía Electrónica , Oocitos/ultraestructura , Espermatozoides/ultraestructura , Bazo/citología
17.
Cell Tissue Res ; 179(3): 357-66, 1977 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-405104

RESUMEN

Aldehyde fixed tissue from monkey (Macaca mulatta) corpus luteum was incubated in alkaline 3,3inch-diaminobenzidine (DAB), and prepared for electron microscopic histochemical observations. The association of microperoxisomes with the granular (GER) or agranular (AER) endoplasmic reticulum was reconstructed from serially sectioned tissues and by tilting of specimens in the microscope. Out of 107 microperoxisomes, 106 were directly associated with the AER. Two different forms of attachment were found between microperoxisomes and the AER and that of the microperoxisome are confluent. In the second, lingulate type of connection, a blunt-end structure either is inserted into an invagination of the AER, or penetrates into the lumen of the AER. The lumen of the lingula is confluent with the microperoxisome, but not with the AER. In addition to these connections, fine thread-like structures were observed extending between AER and adjacent microperoxisomes.


Asunto(s)
Células de la Granulosa/ultraestructura , Macaca mulatta/anatomía & histología , Macaca/anatomía & histología , Microcuerpos , Organoides , Folículo Ovárico/ultraestructura , Animales , Cuerpo Lúteo/ultraestructura , Retículo Endoplásmico , Femenino , Haplorrinos , Microscopía Electrónica
18.
J Chromatogr ; 599(1-2): 141-55, 1992 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-1618987

RESUMEN

Covalent attachment of polyethylene glycol (PEG) chains to the enzyme Cu,Zn-superoxide dismutase (SOD) produces a heterogeneous mixture of modified protein species. The heterogeneity of the product (PEG-SOD) derives from a variable stoichiometric combination of PEG with individual SOD molecules in addition to the polydispersity of the PEG reagent. Characterization of PEG-SOD presents significant challenges due in part to this heterogeneity in addition to the hybrid nature of the modified enzyme. The application of classical methods of protein characterization is not always successful for these PEG-proteins requiring the development of alternative or modified procedures. A series of chromatographic techniques including reversed-phase, ion-exchange, size-exclusion, and hydrophobic interaction high-performance liquid chromatography along with electrophoretic techniques including isoelectric focusing, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and capillary zone electrophoresis have been developed for assessing the degree of heterogeneity of PEG-SOD samples which encompass a range of different stoichiometries. Examples will be given demonstrating the application of these techniques to characterize PEG-SOD samples of different composition produced during the course of the reaction between SOD and an activated PEG reagent.


Asunto(s)
Eritrocitos/enzimología , Polietilenglicoles/química , Superóxido Dismutasa/química , Animales , Bovinos , Cromatografía Líquida de Alta Presión , Electroforesis en Gel de Poliacrilamida , Focalización Isoeléctrica , Espectrofotometría Ultravioleta
19.
Pharm Res ; 17(9): 1098-103, 2000 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11087042

RESUMEN

PURPOSE: The chemical stability and product(s) distribution of adefovir dipivoxil (ADV) was examined in the presence of soluble and insoluble carbonate salts. METHODS: Chemical stability of ADV in the solid state at 60 degrees C/30% RH was examined. Stability was also examined in the presence of excess formaldehyde vapor at 23 degrees C/53% RH. ADV and its degradation product(s) were determined by reverse phase HPLC. RESULTS: Addition of aqueous soluble carbonate salts, such as sodium carbonate, compromised the stability of ADV in solid state. However, aqueous insoluble carbonates, such as calcium carbonate and magnesium carbonate, enhanced the stability of ADV as compared to the control formulation. Pivalic acid, a degradation product of ADV, was shown to accelerate the degradation rate of ADV in solid state. The de-stabilizing effect of this acid on ADV stability was diminished in the presence of magnesium carbonate. Pivalic acid also increased the rate at which ADV dimers were formed in the presence of formaldehyde vapor. Addition of insoluble carbonates reduced the rate of formaldehyde-catalyzed dimerization of ADV. CONCLUSIONS: Addition of insoluble carbonate salts decreased the rate of degradation of ADV by minimizing the extent of formaldehyde-catalyzed dimerization in solid state.


Asunto(s)
Ácidos/farmacocinética , Adenina/análogos & derivados , Antivirales/farmacocinética , Carbonatos/farmacocinética , Organofosfonatos , Adenina/química , Adenina/farmacocinética , Antivirales/química , Química Farmacéutica , Dimerización
20.
Cell ; 54(2): 209-20, 1988 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-3292055

RESUMEN

We have characterized a pre-Golgi, proteolytic pathway for rapid degradation of newly synthesized T cell receptor (TCR) subunits which is insensitive to drugs that block lysosomal proteolysis. The site of degradation in this pathway is either part of or closely related to the endoplasmic reticulum (ER). This "ER" degradative pathway very likely plays an important role in many cells in the removal of unassembled or incompletely assembled membrane protein complexes from the secretory pathway. It is the sole pathway followed by TCR alpha chains and alpha-beta complexes in transfected fibroblasts. In T cells treated with ionophores, which disrupt transport of the TCR from the ER to the Golgi, all newly synthesized alpha, beta, and delta chains are destroyed by this pathway. A variety of biochemical and morphological techniques have been used to distinguish the "ER" degradative pathway from an alternative, lysosomal pathway.


Asunto(s)
Retículo Endoplásmico/metabolismo , Receptores de Antígenos de Linfocitos T/metabolismo , Linfocitos T/metabolismo , Animales , Línea Celular , Centrifugación por Gradiente de Densidad , Densitometría , Electroforesis en Gel de Poliacrilamida , Fibroblastos/metabolismo , Técnica del Anticuerpo Fluorescente , Aparato de Golgi/metabolismo , Hibridomas , Concentración de Iones de Hidrógeno , Inmunoensayo , Inmunohistoquímica , Lisosomas/metabolismo , Ratones , Microscopía Electrónica , Receptores de Antígenos de Linfocitos T/biosíntesis , Linfocitos T/ultraestructura , Temperatura , Transfección
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