Biomedical subjects

D Ortega

Publications and source records attributed to D Ortega.

At least 19 recordsLinked to original sources

PubMed2006

Kilohertz-resolution spectroscopy of cold atoms with an optical frequency comb.

We have performed sub-Doppler spectroscopy on the narrow intercombination line of cold calcium atoms using the amplified output of a femtosecond laser frequency comb. Injection locking of a 657-nm diode laser with a femtosecond comb allows for two regimes of amplification, one in which many lines of the comb are amplified, and one where a single line is predominantly amplified. The output of the laser in both regimes was used to perform kilohertz-level spectroscopy. This experiment demonstrates the potential for high-resolution absolute-frequency spectroscopy over the entire spectrum of the frequency comb output using a single high-finesse optical reference cavity.

Journal Article↗

PubMed2004

[Rectal misoprostol for postpartum hemorrhage].

OBJECTIVE: To evaluate a post-partum hemorrhage treatment guideline, using rectally administered misoprostol. PATIENTS AND METHODS: A descriptive study was carried out in a tertiary referral center from January 2002 to March 2003. During this period, 2670 patients delivered and 41 (1.5%) with severe post-partum hemorrhage unresponsive to oxytocin received 1000 microg of misoprostol (five tablets) rectally while awaiting sulprostone. Twenty-eight had delivered by the vaginal route and 13 by cesarean section. RESULTS: Hemorrhage was controlled among 63% (26/41) of the patients within 10 min of the administration of rectal misoprostol. Fifteen (37%) patients received both misoprostol and sulprostone and no major adverse effects were noted when combining these two prostaglandins. Overall, hemorrhage was controlled among 87% (36/41) of the patients when oxytocics were combined with misoprostol and sulprostone. Five patients (12%) did not respond to the combination of uterotonics and required a conservative surgical treatment. DISCUSSION AND CONCLUSION: Rectal misoprostol may be an effective second line treatment for the management of post-partum hemorrhage unresponsive to oxytocin. We did not observe major side effects when combining misoprostol with sulprostone. Our findings encourage further research on rectal misoprostol in the treatment of postpartum hemorrhage.

Administration, Rectal↗

PubMed2004

Flow cytometry complement-mediated cytotoxicity assay detects baboon xenoantibodies directed to porcine epitopes undetected by hemolytic assay.

The pig-to-primate model is increasingly being utilized as the final preclinical means of assessing therapeutic strategies aimed at allowing discordant xenotransplantation. To obtain information about the nature of cytotoxic response in pig-to-baboon xenotransplants, we sought to determine if serum cytotoxicity in this model was assay dependent. Sera from nine kidney or heart xenotransplanted baboons were obtained before transplantation and at the time of acute humoral xenograft rejection (AHXR). Cytotoxicity was measured by an anti-pig haemolytic assay (APHA) and by a flow cytometry complement-dependent assay (FCCA), using pig blood lymphocytes (PBLs). Serum samples showing inter-assay differences were absorbed with pig erythrocytes and assayed by APHA and FCCA, as well as by measuring anti-alphaGal and total anti-pig xenoantibodies. The results showed that in four AHXR samples, FCCA cytotoxicity was higher than APHA cytotoxicity. Absorption with pig erythrocytes diminished FCCA and removed APHA cytotoxicity. Residual FCCA activity was due to total anti-pig and IgM anti-alphaGal and non-Gal antibodies. Our results indicate that some cytotoxic antibodies present in the sera of xenotransplanted baboons at time of AHXR are IgM antibodies directed against pig PBL antigens not detected by APHA.

Animals↗

PubMed2003

Highly efficient production and characterization of T-DNA plants for rice ( Oryza sativa L.) functional genomics.

We investigated the potential of an improved Agrobacterium tumefaciens-mediated transformation procedure of japonica rice ( Oryza sativa L.) for generating large numbers of T-DNA plants that are required for functional analysis of this model genome. Using a T-DNA construct bearing the hygromycin resistance ( hpt), green fluorescent protein ( gfp) and beta-glucuronidase ( gusA) genes, each individually driven by a CaMV 35S promoter, we established a highly efficient seed-embryo callus transformation procedure that results both in a high frequency (75-95%) of co-cultured calli yielding resistant cell lines and the generation of multiple (10 to more than 20) resistant cell lines per co-cultured callus. Efficiencies ranged from four to ten independent transformants per co-cultivated callus in various japonica cultivars. We further analysed the T-DNA integration patterns within a population of more than 200 transgenic plants. In the three cultivars studied, 30-40% of the T(0) plants were found to have integrated a single T-DNA copy. Analyses of segregation for hygromycin resistance in T(1) progenies showed that 30-50% of the lines harbouring multiple T-DNA insertions exhibited hpt gene silencing, whereas only 10% of lines harbouring a single T-DNA insertion was prone to silencing. Most of the lines silenced for hpt also exhibited apparent silencing of the gus and gfp genes borne by the T-DNA. The genomic regions flanking the left border of T-DNA insertion points were recovered in 477 plants and sequenced. Adapter-ligation Polymerase chain reaction analysis proved to be an efficient and reliable method to identify these sequences. By homology search, 77 T-DNA insertion sites were localized on BAC/PAC rice Nipponbare sequences. The influence of the organization of T-DNA integration on subsequent identification of T-DNA insertion sites and gene expression detection systems is discussed.

Agrobacterium tumefaciens↗

PubMed2003

Monitoring cytotoxicity against pig cells after transplantation using two-color fluorescence viability assay.

Acute humoral xenograft rejection (AHXR) is now the major hurdle for the long-term survival of pig organs transplanted into nonhuman primates. Mechanisms involved in this rejection are not well understood, albeit that it has been proposed to require the participation of antibodies with specificities other than alphaGal. In this study, we evaluated a two-color fluorescence method, fluorescein dicetate (FAD)/propodium iodide (PI), to stain live versus dead cells, respectively, to monitor complement-mediated antibody cytotoxicity in hDAF pig-to-baboon xenotrasplants. FDA/PI flow cytometry assays showed a high correlation (rho Spearman=.736; P=.003) with the cytotoxic activities of baboon serum antibodies against PK15 cells, using either endogenous or exogenous complement. Average serum cytotoxicity against AOC40 was higher (59.82+/-17.90) compared with PK15 (33.69+/-13.05) and L35 (37.64+/-12.77) cells, albeit the difference did not reach statistical significance. Incubation of serum samples with low-molecular weight heparin reduced serum cytotoxicity against PK15 cells in dose-dependent fashion. Therefore, FDA-PI two-color fluorescence is a suitable method to study antibody-mediated cytotoxicity by endogenous or exogenous complement for various pig cells.

Animals↗

PubMed2003

[Conservative surgery of ovarian torsion in pediatrics].

The authors describe the case of two girls diagnosed of ovarian torsion secondary to a cyst. They were operated on by conservative ovarian therapy regardless the time of evolution and ovary macroscopical aspect. These 2 patients were 9 and 13 years old, with abdominal colic pain of 48 and 36 hours of evolution. The diagnosis by doppler sonography was ovarian torsion, with a 4 cms cyst in the right ovary in the first case and a 5 cms cyst in the left ovary in the second patient. Both patients were operated on. After untwisting the ovary, we instille warm saline solution to this ovary and, after waiting for 10 minutes, we resect the ovarian cyst and it recuperates partial and heterogeneous its pink colour. We advise to the family about the possibility of surgical reintervention if the ovary is not viable. After 10 and 12 days of surgical intervention, the Doppler sonography has confirmed the existence of ovary flow and the symmetry of affected ovary in comparation to the opposite on. At the present, both patients are asymptomatic, with exhaustive ultrasound controls. Ovarian torsion is the most frequent complication of ovarian tumours of pediatrics (3-16%) and this is a real emergency in gynecology. Traditionally, it has been recommended the exeresis of ovarian torsion. Regardless the blue aspect of isquemic ovary affected by torsion and the time of evolution, in our experience when there is a minimal possibility of ovarian viability, it is possible to follow a conservative therapy because the macroscopical aspect of the ovary is not necessarily related with the following evolution of the case.

Adolescent↗

PubMed2002

2-Methoxyestradiol induces p53-associated apoptosis of colorectal cancer cells.

Menopausal estrogen replacement therapy is thought to be responsible for the recent decline in colorectal cancer (CRC) incidence among women. In the C57BL/6J-Min/+ mouse, an animal model of CRC, 17beta-estradiol (E(2)) prevents tumor formation in ovariectomized females. We examined human CRC intestinal cell lines to determine whether particular E(2) metabolites produced anti-tumor effects. Treatment of CRC cells with 2-methoxyestradiol (2-MeOE(2)) increased expression of p53 and p21(WAF1/CIP1) proteins and induced apoptosis, but did not produce changes in expression of estrogen receptor (ER)alpha or ERbeta. The finding that 2-MeOE(2) induces p53-mediated colon cell apoptosis in vitro supports a role for 2-MeOE(2) as an endogenous mediator of intestinal tumor suppression.

2-Methoxyestradiol↗

PubMed2001

Tissue harmonic imaging: is it a benefit for bile duct sonography?

OBJECTIVE: Our purpose was to compare tissue harmonic imaging with conventional sonography of the biliary tract. SUBJECTS AND METHODS: Eighty patients with suspect biliary disease had conventional sonography and tissue harmonic imaging with an ATL 3000 or 5000 scanner in a 6-month interval. Final diagnoses included malignant biliary obstruction (n = 30), choledocholithiasis (n = 16), sclerosing cholangitis (n = 4), normal or nonobstructed ducts (n = 16), and miscellaneous conditions (n = 14). Similar images were taken with each technique in terms of projection, field of view, focal zone selection, and evidence of disease. Two separate observers blinded to patient data and technique reviewed and graded images individually for the appearance of the lumen of the bile ducts, the length of the visible duct, the appearance of the duct wall, the presence of any intraluminal masses, and the appearance of associated acoustic shadows. Images were graded from zero to 3, with 3 being the best. RESULTS: The median of the 546 tissue harmonic images was one grade higher than the median for the corresponding conventional images (p < 0.0001). Improvements with tissue harmonic imaging included better sharpness of the duct walls (p < 0.01), a clearer lumen (p < 0.0001), identification of a longer length of the common bile duct (p < 0.0001), and improved detection of intraluminal masses (p < 0.006). Acoustic shadows were better defined and blacker with tissue harmonic imaging (p < 0.007). CONCLUSION: Improvement in contrast and reduction of side lobe artifacts with tissue harmonic imaging enhance visualization of the biliary ducts. Tissue harmonic imaging is now our routine technique for bile duct examination.

Artifacts↗

PubMed2000

Cellubrevin is present in the basolateral endocytic compartment of hepatocytes and follows the transcytotic pathway after IgA internalization.

The endocytic compartment of polarized cells is organized in basolateral and apical endosomes plus those endocytic structures specialized in recycling and transcytosis, which are still poorly characterized. The complexity of the various populations of endosomes has been demonstrated by the exquisite repertoire of endogenous proteins. In this study we examined the distribution of cellubrevin in the endocytic compartment of hepatocytes, since its intracellular location and function in polarized cells are largely unknown. Highly purified rat liver endosomes were isolated from estradiol-treated rats, and the early/sorting endosomal fraction was further subfractionated in a multistep sucrose density gradient, and studied. Analysis of dissected endosomal fractions showed that cellubrevin was located in early/sorting endosomes, with Rab4, annexins II and VI, and transferrin receptor, but in a specific subpopulation of these early endosomes with the same density range as pIgA and Raf-1. Interestingly, only in those isolated endosomal fractions, endosomes enriched in transcytotic structures (of livers loaded with IgA), the polymeric immunoglobulin receptor specifically co-immunoprecipitated with cellubrevin. In addition, confocal and immuno-electron microscopy identification of cellubrevin in tubular structures underneath the sinusoidal plasma membrane together with the re-organization of cellubrevin, in the endocytic compartment, after the IgA loading, strongly suggest the involvement of cellubrevin in the transcytosis of pIgA.

Animals↗

PubMed2000

Migraine without aura and migrainous disorder in children; International Headache Society (IHS) and revised IHS criteria.

The widely used criteria of the IHS to define migraine without aura in children are highly specific but show poor sensitivity, with a large percentage of headaches being classified as migrainous disorder (MD). The objective of this study was to assess how many headache patients in a series of children met the diagnostic criteria of the IHS for migraine without aura or MD and to determine the changes required to convert the greatest number of MD into migraine without aura, without affecting classification of the remaining headache types. A prospective study was undertaken of 131 patients under 15 years old referred to our centre for headache. Patients were classified according to the IHS criteria and according to a modification of these criteria consisting of: (1) reduction of minimum time required for classification into migraine without aura from 2 h to 1 h; (2) acceptance of bifrontal location in addition to hemicranial; (3) acceptance of either phonophobia or photophobia as valid criteria instead of requiring presence of both. Using the IHS criteria, 51 (39%) children were diagnosed as having migraine without aura and 26 (20%) as having MD. According to our revised IHS criteria, 68 (52%) were diagnosed as migraine without aura and nine (7%) as MD. When the three modified criteria were applied, three tension headaches and one unclassifiable headache changed category. When only reduced duration and bifrontal location were applied, none of the headaches other than MD changed category. Application of two modifications to the IHS criteria--reduction in duration of headache to 1 h and acceptance of bifrontal location--increased sensitivity without reducing specificity in classifying migraine without aura in children.

Adolescent↗

PubMed1999

Excretion of lidocaine and bupivacaine in breast milk following epidural anesthesia for cesarean delivery.

BACKGROUND: There is a lack of information and knowledge about the practical importance of even low concentrations of the excretion of local anesthetics into breast milk, particularly concerning bupivacaine. The present work aims to confirm, under practical clinical conditions of admission of parturients, the passage of local anesthetics (lidocaine and bupivacaine) into breast milk after an epidural anesthesia. METHODS: Twenty-seven pregnant women admitted for cesarean delivery received epidural anesthesia with 0.5% bupivacaine and 2% lidocaine. Blood and milk samples were simultaneously collected at 2, 6 and 12 h after the beginning of the epidural infusion. Lidocaine, bupivacaine and its main metabolite, pipecolylxylidide (PPX), were determined in serum and milk by a gas-liquid chromatographic technique. APGAR scores were systematically performed at delivery and a clinical examination was done 24 h after delivery. RESULTS: Our data indicate that lidocaine and bupivacaine as well as PPX are excreted into breast milk. The milk/serum ratio based upon area under the curve values were 1.07 +/- 0.82, 0.34 +/- 0.24 and 1.37 +/- 0.61 mean +/- SD for lidocaine, bupivacaine and PPX, respectively. Most of the newborns had a maximal APGAR score. Our study does not reveal any adverse reactions related to the excretion of local anesthetics into breast milk. CONCLUSION: This study documents the magnitude of excreted lidocaine, bupivacaine and PPX in breast milk, and indicates that the use of both lidocaine and bupivacaine for epidural anaesthesia is safe with regard to breast-feeding.

Adult↗

PubMed1999

[Significance of segmentary reversal defects in the myocardial SPECT with 99mTC-tetrofosmin myocardial SPECT].

OBJECTIVES: To evaluate segmentary reverse defects (RD) (uptake higher in exercise than in rest) in 99mTc-tetrofosmin SPECT. METHODS AND RESULTS: 1,124 consecutive SPECT studies were reviewed and 80 (7%) segmentary RD were identified. Thirty-eight patients with RD attributed to artifact (extra cardiac uptake) were excluded. Thus, 42 patients (3.6%), 21 with and 21 without previous infarct, were studied. Thirteen out of 21 RD in patients without previous infarct corresponded to inferior region and 8 to the anterior region. In three out of 8 patients in whom the coronary angiography was performed, the coronary arteries were angiographically normal and 5 had stenosis of between 50% to 70% of coronary arteries corresponding to RD. Of the 21 RD in patients with previous infarct, the RD site corresponded to the same region of the necrosis (15 inferior and 6 anterior). All had viability criteria (uptake higher than 40% in more than 50% of the region) in rest uptake SPECT quantification. In nine out of 11 patients in whom a coronary angiography was carried out, patency of the artery responsible for the infarct was verified. CONCLUSIONS: 3.6% of segmentary RD, which were not attributed to the artifact, were observed in myocardial perfusion 99mTc-tetrofosmin SPECT studies. Half of these cases corresponded to regions without previous infarct and with normal coronary arteries or non-severe coronary stenosis. The remaining corresponded to regions with previous infarct and with viability criteria.

Convalescence↗

PubMed1998

Stress and rest myocardial SPET quantification with 201Tl and 99Tcm-tetrofosmin: a comparison.

99Tcm-tetrofosmin is a new myocardial perfusion agent that has excellent physical and pharmacokinetic characteristics for performing tomographic myocardial perfusion studies. The aim of this study was to compare the behaviour of 99Tcm-tetrofosmin and 201Tl in the assessment of ischaemia and viability in patients with previous myocardial infarction. Twenty consecutive patients who had suffered infarction and been referred for assessment of ischaemia and myocardial viability were enrolled into the study. Each patient underwent two stress tests performed no more than 10 days apart, one with a 201Tl exercise-reinjection-redistribution method and one with a 99Tcm-tetrofosmin short protocol (exercise-rest). The results were quantified using polar maps to represent images for stress, rest and reversibility. The post-stress images showed there was a slight tendency to overestimate defect size with 99Tcm-tetrofosmin in the lateral region (P < 0.006). We found no significant differences between the two tracers when comparing reversibility. The same defect size at rest were obtained when the maps for 201Tl with uptake of 50% were compared with those for 99Tcm-tetrofosmin with uptake of 45%. Agreement between the two agents for assessment of viability was 93%. We conclude that the quantitative assessment of myocardial ischaemia and uptake of 99Tcm-tetrofosmin at rest are comparable to those obtained with 201Tl in patients who have suffered myocardial infarction.

Adult↗

PubMed1998

Annexin VI defines an apical endocytic compartment in rat liver hepatocytes.

Annexin VI has been demonstrated previously to be a marker for hepatic endosomes. By western blotting with an affinity purified anti-annexin VI antibody it was shown that annexin VI was present in the three morphologically and functionally different endosomal fractions from rat liver. We have quantified the gold-labeled endosomes by immunoelectron microscopy in ultrathin Lowicryl sections of rat liver and now demonstrate that 80% of the total labeling with anti-annexin VI was associated with endocytic structures surrounding the bile canaliculus, the apical domain of hepatocytes, whereas only 20% was found in the subsinusoidal endosomes. In double immuno-gold labeling experiments 80% of the Rab5 positive apical endosomes were also labeled with anti-annexin VI antibodies. However, there was no significant colocalization with antibodies to the polymeric immunoglobulin receptor. Finally, we demonstrate that 50% of endosomes containing internalized gold-labeled transferrin were double labeled with anti-annexin VI antibodies. Thus, annexin VI becomes the first known structural protein at the apical 'early' endocytic compartment of the hepatocyte that may be involved in the receptor recycling and transport to late endocytic/lysosomal compartment pathways.

Animals↗

PubMed1998

Diagnostic accuracy of technetium-99m-MIBI myocardial SPECT in women and men.

UNLABELLED: Noninvasive diagnosis of coronary artery disease in women has some limitations due to a higher percentage of false-positive results. In addition, a lower prevalence of disease can be observed in this population. In this study, we evaluated the diagnostic accuracy of 99mTc-methoxy-isobutyl-isonitrile (MIBI) SPECT in women and men, in a group of patients with proven coronary artery disease by coronary angiography (select minority) and in all patients where a noninvasive test (silent majority) was performed. METHODS: Seven hundred and two consecutive patients without previous myocardial infarction were studied with 99mTc-MIBI myocardial SPECT. One hundred sixty-three patients had coronary angiography (select minority) and 539 did not (silent majority). All patients underwent exercise stress testing, and simultaneous dipyridamole was administered in 32% of patients who did not achieve maximum predicted heart rates. Diagnostic accuracy of the test was calculated for the select minority. Then, sensitivity and specificity of the silent majority were recalculated according to the Diamond criteria. RESULTS: Prevalence of coronary artery disease (32% versus 80%, p = 0.0001) and peak O2 consumption achieved in exercise tests (watts, exercise duration) were lower in women. The probability of positive results of 99mTc-MIBI SPECT also was lower in women (34% versus 65%). The sensitivity of 99mTc-MIBI SPECT in women of the select minority was lower (85% versus 93%, p = 0.01), whereas there was no significant difference for specificity (91% versus 89%). After correcting the results for the silent majority, there were no significant differences in sensitivity (87% versus 88%) and specificity (91% versus 96%) between women and men. These results were not different for patients who achieved maximum predicted heart rates during stress testing (without dipyridamole administration). CONCLUSION: The sensitivity of 99mTc-MIBI myocardial SPECT in women was lower than in men when only the select minority was considered. When the silent majority was considered (correction of selection bias) sensitivity and specificity results did not differ significantly between the sexes.

Cardiac Catheterization↗

PubMed1998

Technetium-99m-HMPAO brain SPECT in Behçet's disease.

UNLABELLED: Behçet's disease (BD) is an idiopathic multisystem disorder. Involvement of the central nervous system (CNS) occurs in 4%-48% of cases. The aim of this study was to evaluate 99mTc-hexamethyl propyleneamine oxime (HMPAO) SPECT findings in BD patients and eventually to detect CNS involvement by depicting cerebral blood flow disturbances. METHODS: Technetium-99m-HMPAO brain SPECT was performed on 33 consecutive BD patients. Qualitative and quantitative evaluation of the cortical uptake was done using an automatic program that generated 32 regions of interest (ROIs). An uptake index for each ROI was obtained. Reference values were obtained from a healthy control group (n = 20). Twenty-five patients also had an MRI study. RESULTS: Twelve of 32 patients (36%) presented with a clinical neurological disorder. SPECT and visual evaluation revealed that 17 patients (51.5%) had abnormalities; 9 of 25 MRI studies (36%) were abnormal. Using the quantitative approach for SPECT, 23 patients (69.7%) had abnormally low values. Six of 12 patients with neurological symptoms had a visually abnormal SPECT scan, whereas quantitative analysis showed abnormalities in 11 patients. Of the 21 patients with no neurological findings, 9 had abnormal SPECT results, and 12 had low uptake indexes. CONCLUSION: HMPAO brain SPECT shows high rates of cerebral blood flow abnormalities in BD patients presenting with neuropsychiatric symptoms, and it also is frequently abnormal in asymptomatic BD patients who have no abnormalities on MR scans. Compared with visual analysis, quantitative analysis detects an even higher rate of SPECT changes in BD patients.

Adolescent↗

PubMed1997

Identification of cytoskeleton-associated proteins in isolated rat liver endosomes.

The polypeptides of three highly purified endosomal fractions isolated from the livers of oestradiol-treated rats were analysed by Western blotting, and the amount and distribution of intrinsic and cytoskeletal-associated proteins were quantified and studied. The 'late' endosomes [multivesicular bodies (MVBs)] had the lowest content of cytoskeletal-associated proteins, the most significant being the presence of 25% of the total dynein found in endosomes. The 'early' endosome [compartment of uncoupling receptors and ligands (CURL)] fraction contained kinesin (40% of the total in endosomes), dynein (23%), actin (15%) and tubulin (10%). The receptor-recycling compartment (RRC), also demonstrated to be involved in transcytosis, contained the largest number and enrichment of cytoskeletal proteins: actin (84% of the total in endosomes), alpha-actinin (90%), dynein (52%), tubulin (91%) and kinesin (45%). We also analysed and compared the presence of different endosomal markers such as Rab4, Rab5 and cellubrevin (vesicle soluble NSF attachment protein receptor) in CURL (41%, 15% and 60%) and in RRC (44%, 75% and 30% respectively). Finally, the expression of annexins I, II, IV and VI was studied: annexin I was equally distributed between MVBs and CURL; annexin II was highly enriched in RRC (95%), annexin IV was equally distributed between CURL and RRC, and annexin VI was enriched in CURL (57%). The results indicate that isolated rat liver endosomes contain all the required molecular machinery for the achievement of their role in intracellular trafficking.

Animals↗

PubMed1997

Identification and distribution of proteins in isolated endosomal fractions of rat liver: involvement in endocytosis, recycling and transcytosis.

1. The polypeptides of the three endosomal fractions isolated from livers of oestradiol-treated rats were analysed by two-dimensional gel electrophoresis. Silver-stained gels revealed that although the three endosomal fractions shared a generally similar pattern of approx. 120 components, qualitative and quantitative differences between the three endocytic fractions could be demonstrated. 2. The 'early' endosomes [compartment of uncoupling of receptors and ligands (CURL)] comprised the most complex fraction and contained most of the polypeptides found in the 'late' endosomes [multivesicular bodies (MVBs)] and the receptor recycling compartment (RRC). When CURL was analysed by two-dimensional gel electrophoresis after partition with Triton X-114, it showed the largest number of integral membrane polypeptides. 3. Some of the major receptors (polymeric immunoglobulin receptor, transferrin receptor, low-density lipoprotein receptor, asialoglycoprotein receptor, beta1-integrin, mannose 6-phosphate receptor, epidermal growth factor receptor and AGp110) and internalized ligands (IgA, IgG, albumin, haptoglobin, transferrin and alpha2-macroglobulin) were further studied by Western blotting. 4. The distribution of the identified receptors and ligands among the three endosomal fractions was in agreement with their expected functionalities. 5. The polypeptide composition of the bile was also examined and compared with ligands and proteins identified in the different endocytic fractions. 6. Finally, an electron microscopy study confirms the distinctive physical and ultrastructural features of the three isolated endosomal fractions.

Animals↗