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Biomedical subjects

A Rios

Publications and source records attributed to A Rios.

At least 19 recordsLinked to original sources
PubMed2006

Subcellular distribution of the Entamoeba histolytica 140 kDa FN-binding molecule during host-parasite interaction.

Entamoeba histolytica trophozoites recovered from the host-parasite interface during abscess development obtain different stimuli compared with long-term cultured cells. In order to have a better understanding about the mechanisms in which the 140 kDa fibronectin (FN)-binding molecule (EhFNR) is involved during the invasive process, we decided to compare the regulation process of this molecule among long-term cultured trophozoites, FN-stimulated trophozoites, and trophozoites recently recovered from a liver abscess. A cDNA clone (5A) containing a fragment of the EhFNR that shows identity to the C-terminal region of the intermediate galactose lectin subunit Igl, was selected with a mAb (3C10). Identity of EhFNR with Igl was confirmed by immunoprecipitation with 3C10 and EH3015 (against the Gal/GalNAc intermediate subunit) mAbs. The 3C10 mAb was used as a tool to explore the modulation of the amoebic receptor (EhFNR). Our results showed specific regulation of the EhFNR in FN-interacted amoebas, as well as in trophozoites recovered at different stages of abscess development. This regulation involved mobilization of the receptor molecule from internal vesicles to the plasma membrane. Therefore, we suggest that in the host-parasite interface, the EhFNR (Igl) plays an important role in the adhesion process during abscess development.

Amino Acid Sequence↗
PubMed2006

Frequency analysis of air and skin temperature in neonates in servo-controlled incubators.

OBJECTIVE: To test a new system designed for digital recording of skin and air temperature, thereby allowing analysis of cyclic changes in temperature in neonates in servo-controlled incubators. METHODS: Analysis of cyclic changes of serial skin and air temperature in asymptomatic infants in servo-controlled incubators adjusting heat output to the patient's temperature. RESULTS: In nine asymptomatic neonates ranging from 25 to 40 weeks of gestational age, analysis showed peaks of coherence (squared correlation) between skin and air temperature measurements at periods ranging between 1.5 and 3 h. CONCLUSION: We have established a new system to study cyclic changes in skin and air temperature in neonates in servo-controlled incubators. The analysis of this pilot study suggests that the most important changes in skin and air temperature in asymptomatic neonates occur at a periodicity of 1.5 to 3 h, which is similar to that previously described for neonatal temperature. Additional data are required to determine whether this new system may be useful in neonatal care.

Air Conditioning↗
PubMed2005

Definitive treatment for persistent hypoparathyroidism in a kidney transplant patient: parathyroid allotransplantation.

Post-surgical hypocalcemia is usually a transitory complication in thyroid and parathyroid surgery that can be resolved quickly, although it becomes a delicate matter when the problem persists. Parathyroid transplantation is the choice of treatment; however, the associated immunosuppression can cause side effects. The following case study shows the transplantation of parathyroid tissue from a patient with secondary hyperparathyroidism to another kidney transplant patient with severe hypocalcemia that was medically intractable. The graft is functioning after 2 years.

Adult↗
PubMed2004

Primitive leiomyosarcoma of the breast: case report and review of the literature.

Sarcomas of the breast account for under 1% of breast tumours. Leiomyosarcomas are less common, being a subgroup of sarcomas of the breast. Only 23 cases with immunohistochemical or electron microscopy confirmation are reported in the literature. The case of a 58-year-old woman with a leiomyosarcoma 4 cm in diameter in the upper external quadrant of the right breast is presented. Mammography and sonography were compatible with a fibroadenoma or phylloides tumour, and fine-needle aspiration (FNA) suggested medullary carcinoma. The patient underwent a Madden-type modified radical mastectomy and axillary lymphadenectomy. Adjuvant chemotherapy was implemented with Adriamycin (four cycles of 21 days). One year after surgery the patient is tumour free.

Breast Neoplasms↗
PubMed2003

Does the standard vs piggyback surgical technique affect the development of early acute renal failure after orthotopic liver transplantation?

The objective of this study was to evaluate the effect of the surgical technique on postoperative renal function during the first week after liver transplantation (OLT). We performed a retrospective study of 184 consecutive OLT. Criteria for acute renal failure were: serum creatinine >1.5 mg/dL, an increase by 50% in the baseline serum creatinine, or oliguria requiring renal replacement therapy. The distribution of patients according to the surgical technique was: standard (n=84), venovenous bypass (n=20), and piggyback (n=80). Other variables analyzed were: intraoperative requirement for blood products, treatment with adrenergic agonists, intraoperative complications, and postreperfusion syndrome. Univariate analysis showed the following parameters to be significantly related to postoperative renal failure: intraoperative fresh frozen plasma and cryoprecipitate requirements, intraoperative complications, postreperfusion syndrome, need for noradrenaline or dobutamine, standard surgical technique versus piggyback (39% vs 18%, P<.01) and venovenous vs piggyback (50% vs 18%, P<.01). Logistic regression analysis identified the following variables as having independent prognostic value: (1) Standard surgical technique vs piggyback (OR=3.3, P=.01); (2) venovenous vs piggyback (OR=4.7, P=.02); and (3) >20 U cryoprecipitate requirement (OR=1.04, P=.01). In conclusion, compared with the piggyback technique, the standard surgical technique appears to be an independent risk factor for postoperative acute renal failure. When venovenous bypass is used in patients who do not tolerate trial clamping of inferior vena cava, it does not reduce the incidence of postoperative renal failure. Finally, the piggyback technique significantly reduces the probability of acute renal failure after liver transplantation.

Acute Kidney Injury↗
PubMed2001

Presenilin-1-associated abnormalities in regional cerebral perfusion.

OBJECTIVE: To investigate the influence of the presenilin-1 gene (PS-1) mutation on regional cerebral perfusion, SPECT was evaluated in 57 individuals. The subjects were members of a large pedigree from Colombia, South America, many of whom carry a PS-1 mutation for early-onset AD. METHODS: Members of this large kindred who were cognitively normal and did not carry the PS-1 mutation (n = 23) were compared with subjects who were carriers of the mutation but were asymptomatic (n = 18) and with individuals with the mutation and a clinical diagnosis of AD (n = 16). Cerebral perfusion was measured in each subject using hexamethylpropyleneamine oxime SPECT. The data were analyzed in two ways: 1) Mean cerebral perfusion in each of 4320 voxels in the brain was compared among the groups using t-tests (t-maps); and 2) each individual received a weighted score on 20 vectors (factors), based on a large normative sample (n = 200), using a method known as singular value decomposition (SVD). RESULTS: Based on t-maps, subjects with the PS-1 mutation who were asymptomatic demonstrated reduced perfusion in comparison with the normal control subjects in the hippocampal complex, anterior and posterior cingulate, posterior parietal lobe, and anterior frontal lobe. The AD patients demonstrated decreased perfusion in the posterior parietal and superior frontal cortex in comparison with the normal control subjects. Discriminant function analysis of the vector scores derived from SVD (adjusted for age and gender) accurately discriminated 86% of the subjects in the three groups (p < 0.0005). CONCLUSION: Regional cerebral perfusion abnormalities based on SPECT are detectable before development of the clinical symptoms of AD in carriers of the PS-1 mutation.

Adult↗
PubMed2001

Respiratory mechanics in very low birth weight infants during continuous versus intermittent gavage feeds.

This study was designed to determine whether respiratory mechanics in stable, very low birth weight infants changed after replacing intermittent feeds with continuous feeding. We measured static respiratory system compliance, respiratory system resistance, functional residual capacity (FRC), and tidal volume immediately before feeds and at 20, 60, and 120 min after feeds, and again the next day on continuous feeds. Patients selected for enrollment into the study needed to fulfill the following criteria: 1) birth weight and postnatal weight < 1,500 g, 2) no need for mechanical ventilation, positive airway pressure, or supplemental oxygen, 3) receiving and tolerating at least 100 mL/kg/day of intermittent gavage feeds, and 4) no change in methylxanthine or diuretic dosage for 3 days before the study. Respiratory mechanics were measured using the SensorMedics 2600 Pediatric Pulmonary Cart (Yorba Linda, CA). We studied 16 infants (gestational age 28.3 +/- 3.7 weeks, mean +/- SD) at a postnatal age of 10-82 days. The average interindividual coefficient of variance was 20 +/- 2% for static compliance, 35 +/- 6% for resistance, 18 +/- 3% for FRC, and 19 +/- 3% for tidal volume. Repeated-measures analysis of variance did not reveal any significant difference in respiratory mechanics with intermittent vs. continuous feeding. The data suggest that static respiratory mechanics in stable, very low birth weight infants are not affected by changing enteral feeds from intermittent gavage to a continuous schedule.

Enteral Nutrition↗
PubMed2001

Entamoeba histolytica: monoclonal antibody against the beta1 integrin-like molecule (140 kDa) inhibits cell adhesion to extracellular matrix components.

We describe a monoclonal antibody (3C10) against the beta1 integrin-like molecule which immunoprecipitates two polypeptides of 140 and 155 kDa from detergent-soluble extract of Entamoeba histolytica. The 140-kDa polypeptide has been described as a beta subunit of the amoebic fibronectin receptor as it is recognized by an anti-integrin beta1 (human) monoclonal antibody in immunoblot assay. The receptor molecules were localized with the 3C10 monoclonal antibody in intracellular and surface membranes of E. histolytica trophozoites by immunofluorescence and immunogold labeling methods. Significant inhibitions of cell adhesion on extracellular matrix proteins such as fibronectin (56%) (P < 0.001) and collagen (50%) (P < 0.001) and partial inhibition on laminin (23%) (P > 0.1) were achieved by the monoclonal antibody.

Animals↗
PubMed2001

Factors that affect recurrence after incisional herniorrhaphy with prosthetic material.

OBJECTIVE: To evaluate the risk factors for recurrence after prosthetic incisional herniorrhaphy. DESIGN: Retrospective study. SETTING: Tertiary referral centre, Spain. PATIENTS: 246 patients who had incisional herniorrhaphy with a prosthetic material (polypropylene) between 1990 and 1997 INTERVENTIONS: A reinforcement mesh was inserted when the hernia was more than 5 cm. In incisional hernias less than 5 cm the reinforcement mesh was inserted when the repair was under tension or when tissues were noted to be weak during the operation. MAIN OUTCOME MEASURES: Age, sex, obesity, the presence of bronchial disease, previous repair of the incisional hernia, type of surgery, size and site of hernia and presence of local complications during the immediate postoperative period. RESULTS: Mean (SD) follow-up was 77 (6) months (minimum follow up two years). The hernia recurred in 43 cases (17%) (mean time of recurrence 10 (8) months). Age over 60 years, previous herniorrhaphy, size of hernia, and postoperative local complications were significant risk factors (p < 0.01) in both the univariate and multivariate analyses. CONCLUSIONS: Patients at the greater risk of recurrence are those aged over 60 years, with large, recurrent hernias and who develop local complications during the postoperative period.

Age Factors↗
PubMed2001

Recurrent papillary thyroid cancer: analysis of prognostic factors including the histological variant.

OBJECTIVE: To analyse the factors that influence the development of recurrent papillary thyroid carcinoma, including the histological variant. DESIGN: Retrospective study. SETTING: Teaching hospital, Spain. SUBJECTS: 200 patients who had papillary thyroid cancers resected between 1970 and 1995. MAIN OUTCOME MEASURES: Prognostic factors and disease-free interval assessed by univariate and multivariate analysis. RESULTS: All patients were followed up for a mean of 9 years (range 4-29). 54 patients presented with recurrent disease (27%) of whom 19 (35%) died of their disease. 5-year, 10-year, and 15-year survival for those with recurrent disease were 75%, 68%, and 60%, respectively. The corresponding figures for the whole series were 93%, 90%, and 84%. The significant variables on multivariate analysis were completeness of resection (p = 0.002), extrathyroid involvement (p < 0.002), presence of lymph node metastases (p = 0.002), and histological variant of the carcinoma (P < 0.001). CONCLUSION: Using these risk factors it is possible to draw up a prognostic index and classify patients as being at low, medium, or high risk of recurrence.

Adolescent↗
PubMed2001

Intestinal metaplasia in patients with columnar lined esophagus is associated with high levels of duodenogastroesophageal reflux.

OBJECTIVE: To evaluate the rate of duodenogastroesophageal reflux in patients with columnar lined esophagus compared with patients with gastroesophageal reflux disease without columnar lined esophagus, and to analyze whether it is related to the presence of specialized columnar epithelium in the metaplastic segment. SUMMARY BACKGROUND DATA: The carcinomatous degeneration of columnar lined esophagus originates from a specialized columnar epithelium. The appearance of this metaplastic phenomenon is clearly related to severe prolonged gastroesophageal reflux, but only some of these patients finally develop columnar lined esophagus. For this reason other factors have been suggested, particularly the role played by the reflux of duodenal contents into the esophagus. METHODS: The authors studied 15 healthy volunteers (control group), 10 patients with reflux symptoms but without endoscopic lesions, 20 patients with reflux esophagitis without columnar lined esophagus, and 35 patients with columnar lined esophagus (complicated with ulcers or stenosis in 8 cases), of whom 22 had intestinal metaplasia. To assess the reflux of duodenal contents into the esophagus, all the patients underwent Bilitec 2000 and 24-hour esophageal pH monitoring. RESULTS: The presence of bilirubin in the material refluxed into the esophagus was greater in the patients with columnar lined esophagus than in the rest of the groups. Likewise, duodenogastroesophageal reflux was greater in the columnar lined esophagus patients who had intestinal metaplasia. CONCLUSIONS: Duodenogastroesophageal reflux may play a major role in the development of columnar lined esophagus, especially in patients with intestinal metaplasia.

Adult↗
PubMed2000

Angiotensin II modulates ion transport in rat proximal tubules through CYP metabolites.

To assess the effect of angiotensin II on ion transport in rat isolated proximal tubules and establish the arachidonic acid cytochrome P450 metabolites' role mediating angiotensin II effect and to analyze whether corticosteroids play a role modulating this effect, we studied the effect of low (10 and 100 pM) and high (0.1-1 microM) angiotensin II concentrations on proximal tubule ion transport, measured as (86)Rb uptake. Low angiotensin II produced a stimulation on the (86)Rb uptake (195.79 +/- 35, 377.9 +/- 81, and 300 +/- 49 pg (86)Rb/microg protein/2 min, for control and 10 and 100 pM angiotensin II, respectively). High angiotensin II concentration inhibited ion transport (0.1 microM, 57.9 +/- 5 and 1 microM, 47.3 +/- 4 pg (86)Rb/microg protein/2 min), this effect was prevented by 17-ODYA and by losartan, while indomethacin had no effect. Dexamethasone treatment increased angiotensin II-induced (86)Rb uptake inhibition and arachidonic acid metabolism (19-, 20-HETE and 12-HETE), while adrenalectomy partly prevented angiotensin II-induced inhibition and decreased cytochrome P450-dependent arachidonic acid metabolism. In conclusion, high doses of angiotensin II produce inhibition of ion transport in rat isolated proximal tubules; this effect is mediated by AT(1) receptors, involves cytochrome P450-dependent arachidonic acid metabolites, and is upregulated by corticosteroids.

Adrenalectomy↗
PubMed2000

Entamoeba histolytica: tyrosine kinase activity induced by fibronectin through the beta1-integrin-like molecule.

Previously, we characterized a 140-kDa protein from Entamoeba histolytica as a beta1-integrin-like molecule that binds fibronectin. In this work we present data showing that the amoebic receptor is associated with another surface molecule, the 220-kDa lectin, and with protein tyrosine kinase activity. By immunoprecipitation with the alphabeta1Eh antibody, we demonstrated by immune complex assays for tyrosine protein kinases that the amoebic fibronectin receptor was associated with two phosphorylated proteins of 50 and 70 kDa when internal membranes were used as the source of antigen. When cells were stimulated with fibronectin, two proteins of 55 and 90 kDa were tyrosine phosphorylated, as shown by Western blot with alphaPY20, its phosphorylation being time dependent after fibronectin stimulation. However, when the actin cytoskeleton of fibronectin-stimulated trophozoites was stabilized with phalloidin, the level and the pattern of phosphorylated proteins were different. In this case, a high-molecular-weight component, heavily phosphorylated, was present, which may include the 220-kDa lectin. We also present data confirming that the signaling pathway that is activated by fibronectin is specific. This was demonstrated by comparing the pattern of phosphoproteins obtained in immune complexes prepared with alphabeta1Eh, alphaL220, and alphaPY20 from total extracts obtained in the presence of phalloidin, from cells that had been exposed to fibronectin, soluble concanavalin A, or concanavalin-A-coated substrate. The presence of tyrosine kinases associated with the beta1-integrin-like amoebic molecule was confirmed by immunoprecipitation assays along with the combined use of a tyrosine kinase-specific substrate, the peptide RR-SRC, and a tyrosine kinase inhibitor, genistein.

Animals↗
PubMed2000

Clinical and cerebral blood flow changes in catatonic patients treated with ECT.

OBJECTIVE: To determine changes in clinical manifestations and cerebral blood flow (CBF) before and after administration of ECT to patients with catatonia due to schizophrenia or mood disorders. METHODS: A sample of nine patients who met DSM-IV criteria for catatonia was studied. Patients received between 5 and 15 sessions (thrice per week) of ECT. Severity of catatonia was measured with the Modified Rogers Scale (MRS). Changes in CBF were measured with a brain single positron emission computer tomography (SPECT) that was performed 1 week before the first ECT and 1 week after the last ECT. RESULTS: Catatonia was due to schizophrenia in five patients and mood disorders in four patients. There were no significant clinical and brain SPECT differences between these two groups before treatment. Pre- vs. post-ECT comparisons showed significant reduction of catatonic symptoms in both groups. However, patients with mood disorders needed less ECT sessions and showed greater clinical improvement. Brain SPECT showed significant increase in CBF in parietal, temporal, and occipital regions in patients with mood disorder and no significant changes in patients with schizophrenia. CONCLUSIONS: These results support the efficacy of ECT for treatment of catatonic patients, especially secondary to mood disorders, which seem to be correlated with improvements in CBF.

Adolescent↗