Search PubMed⌕ Search

Biomedical subjects

F Moya

Publications and source records attributed to F Moya.

At least 19 recordsLinked to original sources
PubMed2005

Is magnetic resonance imaging safe in cardiac pacemaker recipients?

Magnetic resonance imaging (MRI) is currently contraindicated in cardiac pacemaker (PM) recipients. The objectives of this prospective study were to (1) reassess the risks of performing an MRI scan in patients with PM, (2) compared the pacing functions before and after the exposure to MRI, and (3) monitor the development of possible adverse effects. Thirteen patients implanted with an Affinity DR model 5330 PMs (St. Jude Medical) connected to a Tendril model 1388 leads (St. Jude Medical) underwent 2.0 T-MRI for a variety of indications. All patients displayed a stable spontaneous rhythm at the time of the MRI scan and were not considered to be PM-dependent. The sensing and pacing functions were analyzed and the impedance of both leads was measured before and after the scan. The MRI scan was performed with all PM programmed in DDD mode. The sensing configuration was bipolar. All patients were monitored utilizing a standard electrocardiographic monitor and direct verbal communication. PM Inhibition, asynchronous pacing, or inappropriately rapid pacing was not observed. No patient reported discomfort, heat, or motion sensation at the PM implant site. There were no significant differences in the sensing, stimulation, AutoCapture threshold, and lead impedance measurements before and after MRI. The results of this study suggest that performing 2.0 T-MRI scans in patients with Affinity DR model 5330 PM connected to a Tendril model 1388 lead is safe.

Aged↗
PubMed2000

Late versus early surgical correction for congenital diaphragmatic hernia in newborn infants.

BACKGROUND: Congenital diaphragmatic hernia, although rare (1 per 2-4,000 births), is associated with high mortality and cost. Opinion regarding the timing of surgical repair has gradually shifted from emergent repair to a policy of stabilization using a variety of ventilatory strategies prior to operation. Whether delayed surgery is beneficial remains controversial. OBJECTIVES: To summarize the available data regarding whether surgical repair in the first 24 hours after birth rather than later than 24 hours of age improves survival to hospital discharge in infants with congenital diaphragmatic hernia who are symptomatic at or immediately after birth. SEARCH STRATEGY: Search of Medline (1966-1999), Embase (1978-1999) and the Cochrane databases using the terms "congenital diaphragmatic hernia" and "surg*"; citations search, and contact with experts in the field to locate other published and unpublished studies. SELECTION CRITERIA: Studies were eligible for inclusion if they were randomized or quasi-randomized trials that addressed infants with CDH who were symptomatic at or shortly after birth, comparing early (<24 hours) vs late (>24 hours) surgical intervention, and evaluated mortality as the primary outcome. DATA COLLECTION AND ANALYSIS: Data were collected regarding study methods and outcomes including mortality, need for ECMO and duration of ventilation, both from the study reports and from personal communication with investigators. Analysis was performed in accordance with the standards of the Cochrane Neonatal Review Group. MAIN RESULTS: Two trials met the pre-specified inclusion criteria for this review. Both were small trials (total n<90) and neither showed any significant difference between groups in mortality. Meta-analysis was not performed because of significant clinical heterogeneity between the trials. REVIEWER'S CONCLUSIONS: There is no clear support for either immediate (within 24 hours of birth) or delayed (until stabilized) repair of congenital diaphragmatic hernia, but a substantial advantage to either one cannot be ruled out. A large, multicenter randomized trial would be needed to answer this question.

Age Factors↗
PubMed2000

16. FDG-PET in the Detection of Recurrence in Colorectal Cancer Based on Rising CEA Level. Experience in 72 Patients.

Purpose: A rising CEA level after the resection of colorectal cancer is an early indicator of tumour recurrence. However, conventional imaging techniques have limited sensitivity for detecting recurrent disease in such patients. Our group has evaluated the role of Positron Emission Tomography with 18F-Fluorodeoxiglucose (FDG-PET) in this clinical situation.Material and Methods: Seventy-two patients with abnormal CEA levels and normal results of conventional methods of tumour detection were studied with FDG-PET. The PET results were compared with pathologic findings (n = 25) long-term radiological (n = 9) and clinical follow-up (n = 38). Influence of PET findings in therapeutic management was also considered in this study.Results: PET detected lesions in 63/72 patients (87.1%). Metabolic imaging showed metastases in the liver (44.1%), ganglionar nodes (27.5%), local recurrence (20.4%) and lung metastases (8%). Overall, the sensitivity of PET was 94.4%, specificity was 83.3%, the positive-predictive value was 97.1%, the negative-predictive value was 71.4% and the diagnostic accuracy was 92.8%. FDG-PET findings change therapeutic decision in 68/72 patients (94.1%)Conclusion: When conventional examinations are normal, FDG-PET is a valuable imaging tool in patients who have rising CEA level after colorectal surgery. Metabolic imaging represents a very cost-effectiveness diagnostic procedure in this clinical situation, avoiding unnecessary invasive techniques.

Journal Article↗
PubMed2000

17. Utility of Metabolic Imaging in Oral Squamous Cell Carcinoma (SCC) Staging. Experience in 30 Patients.

Purpose: SCC represents nearly 90% of all oral malignancies, with an increasing incidence. Accurate Tumour-Node-Metastasis staging (TNM) is mandatory for planning surgical options and chemotherapy-radiotherapy management. Positron Emission Tomography (PET) using 18F-Fluorodeoxyglucose (FDG) provides functional information about tumoral tissues that may improve preoperative staging obtained by conventional morphologic procedures (CT-MRI). The purpose of this study is to evaluate the accuracy of FDG-PET in oral SCC staging and to compare those data from conventional and PET studies according to the pathologic results obtained from surgical specimen.Methods: A prospective study of 30 patients was carried out, through a 26 months period. Inclusion criteria include positive biopsy for Oral SCC, no other malignancies during the past 5 year and surgery as preferred therapeutic option. All patients underwent CT, MRI, and FDG-PET studies consecutively. Results obtained from conventional and PET preoperative staging were compared with those from postoperative histopathological studiesResults: FDG-PET modified preoperative staging obtained by conventional morphologic studies in 21% cases, which was confirmed postoperatively by histological findings. Kappa test showed higher values for PET studies (0.89) than conventional studies (0.41), when compared with postoperative controlConclusion: FDG-PET may be helpful to improve the accuracy of conventional studies in oral SCC preoperative TNM staging, although no definitive conclusions can be withdrawn due to the limited size of the sample. Modifications of preoperative staging showed by PET are a matter of controversy and must be kept in mind for further studies.

Journal Article↗
PubMed2000

Clinical Impact of 18F-FDG-PET in the Suspicion of Recurrent Ovarian Carcinoma Based on Elevated Tumor Marker Serum Levels.

Purpose: To retrospectively evaluate the contribution of 18F-fluorodeoxy-glucose-positron emission tomography (FDG-PET) to the diagnosis and clinical management of patients who were suspected of recurrent ovarian carcinoma, based on elevated tumor markers levels with normal or equivocal computed tomography (CT) or nuclear magnetic resonance (NMR).Procedures: 20 patients with these characteristics underwent FDG-PET. PET findings were confirmed in 14, in 7 by surgery, and in the other 7 by clinical course.Results: Recurrence was confirmed in 12 patients, all with FDG-PET positive. In other 2, recurrence was rule out and in 1, FDG-PET was negative. FDG-PET accuracy was 93% with 4 surgeries avoided and guided other 6.Conclusions: FDG-PET is an useful technique for detecting recurrent ovarian carcinoma suspected by elevated tumor markers levels and normal or equivocal results in the morphologic imaging techniques and has an important clinical impact on the management of these patients.

Journal Article↗
PubMed1999

Comparative study of the physical properties of a polyacid-modified composite resin and a resin-modified glass ionomer cement.

OBJECTIVES: The physical properties of the resin-modified composite resin Dyract (Detrey Dentsply) and the resin-modified glass ionomer cement Fuji II LC (GC) were compared, and the effect of water sorption on these properties was studied. METHODS: Compressive, diametral compressive and flexural strengths were measured using specimens aged up to three months. The Vickers hardness and the water erosion were also determined. The specimens were stored at 37 degrees C under five different conditions, chosen to vary the water sorption of the samples. The results were analyzed using a multi-factor analysis of variance. RESULTS: Dry specimens of Dyract and Fuji II LC showed similar properties. However, the two materials behaved differently when stored in presence of water. In contrast to Fuji II LC, Dyract showed very little expansion for the first 24 h (1.5 +/- 0.3 and 0.03 +/- 0.01%, respectively), leached small quantities of ions and retained its mechanical strength. Those differences are related to their chemical composition. Fuji II LC is hydrophilic, as it contains polyHEMA. In the presence of water, Fuji II LC behaves like a hydrogel, but the network resulting from the copolymerization of acidic and UDMA monomers is less hydrophilic, and the effect of water on Dyract is retarded. SIGNIFICANCE: The significant properties of Dyract are determined by its composite character. This certainly represents some advantages, for instance, a higher mechanical strength, a better protection against initial dehydration and subsequent water effects. However, Dyract shows some disadvantages over Fuji II LC, like a lower amount of fluoride release or the interference of oxygen during polymerization.

Absorption↗
PubMed1999

Effect of water on the physical properties of resin-modified glass ionomer cements.

OBJECTIVES: Resin-modified glass ionomer cements (GIC) are available for clinical use as restorative materials or as liners and bases. This work was conducted to study the effect of water sorption on the physical properties of several resin-modified GIC, by changing the samples' storage conditions. METHODS: The water sorption, the flexural strength, the flexural elastic modulus, the Vickers hardness and the dimensional changes of five resin-modified GICs were measured using specimens aged for 24 h to 3 mon. The specimens were stored at 37 degrees C, either in a dry environment (A), immersed in water (B), stored in a humid environment (C), stored in a humid environment for 1 h and then immersed in water (D), or immersed in water and subsequently dried (B + A). An analysis of variance was used to compare the results. RESULTS: The resin-modified GIC absorb during the first 24 h large amounts of water (114-172 mg/cm3) compared to the conventional GIC (30-63 mg/cm3). Water alters the physical properties of resin-modified GICs: With regard to dry specimens, a decrease in the flexural strength of 20 to 80% was observed for samples immersed in water. Decreases in their flexural elastic modulus (50 to 80%) and in their hardness (approximately 50%) were also observed. Water sorption also provoked an expansion in volume of the immersed specimens, ranging from 3.4 to 11.3% after 24 h. SIGNIFICANCE: The flexural strength and Vickers hardness of the resin-modified GICs are sensitive to the water contained in the tested specimens. A correlation was established between the decrease in their physical properties and the water uptake. However, it should not be concluded that these materials are not adequate for use in applications in direct contact with oral fluids. Probably, resin-modified GIC placed in oral cavities would not be affected to the same extent as in in vitro tests. In an oral environment, the constituents of saliva will certainly decrease the rate of water sorption and will hence delay its effects.

Absorption↗
PubMed1998

[Transient radicular nerve conduction block in patients with intermittent neurogenic claudication].

Patients with neurogenic claudication do not usually exhibit symptoms at rest. The diagnosis is uncertain when there are no signs of lumbar radiculopathy. However, the functional deficiary could show up during a brief time at presentation of the symptoms if appropriate electrophysiological techniques are used to measure nerve conduction at the radicular segment. In 8 patients with neurogenic claudication, we examined the curve of recruitment of the soleus H reflex and in four of them the chronodispersion of the F wave of the posterior tibial nerve, before and after walking was also examined. Both studies showed normal results before walking in all patients. The H wave showed a transient diminution of excitability in 6 patients after walking, which lasted for a mean period of 7 min. Only one of these patients also showed an increase in the chronodispersion of the F wave. Our data suggest that conduction is transiently blocked in large myelinated fibers at a radicular level in patients with neurogenic claudication after walking. This could partially explain the symptoms of neurogenic claudication.

Adult↗
PubMed1998

Spinal anesthesia for cesarean section. 1963.

Safety in spinal anesthesia for cesarean section is achieved by strict adherence to the cardinal principles of proper evaluation and selection of patients, the use of prophylactic vasopressors, preanesthetic establishment of a reliable intravenous channel, small doses of the local anesthetic, close monitoring and maintenance of systolic blood pressure above 100 mm. Hg, and avoidance of ergot compounds in the presence of vasopressors.

Anesthesia, Obstetrical↗
PubMed1996

Insulin-like growth factors (IGFs) and IGF binding proteins-1, -2, and -3 in newborn serum: relationships to fetoplacental growth at term.

Cord sera were obtained from term, Chilean newborns exhibiting various patterns of intrauterine growth and assayed for IGF-1, IGF-2, IGFBP-1, IGFBP-2, and IGFBP-3 by specific radioimmunoassays (RIA). Serum levels of each peptide were correlated with birth weight (BW), ponderal index (PI), and placental weight (PW). Total IGF-1 levels correlated with BW (r = 0.665, P = 0.0001). PI (r = 0.527, P = 0.004), and PW (r = 0.596, P = 0.0017). In contrast, IGF-2 failed to correlate with any growth parameter. Of the three binding proteins, IGFBP-3 exhibited the strongest relationship to each growth parameter. IGFBP-3 correlated significantly with BW (r = 0.71, P < 0.0001), PI (r = 0.782, P < 0.0001), and PW (r = 0.57, P = 0.0029). In addition IGFBP-3 levels positively correlated to IGF-1 levels (r = 0.614, P = 0.0005). By contrast, circulating IGFBP-1 and IGFBP-2 were inversely related to IGF-1 levels. All five peptides were subjected to multiple regression analysis and related to BW. Significant relationships between the predicted BW and the actual BW were observed in these infants (r = 0.802, P = 0.0006). The BWs of a cohort of unrelated North American infants were also predicted using the Chilean-derived equation and found to be significantly related to their actual BWs (r = 0.453, P = 0.0033). These relationships were strengthened by the inclusion of estimated gestational age (EGA) as an independent variable. These data point to particularly important roles for IGF-1 and IGFBP-3 in regulating fetal growth at term, and suggest that they are regulated in a coordinated manner during the latter stage of gestation. Furthermore, they suggest that IGFBPs play multiple, and potentially opposing, regulatory roles in modulating IGF action. Lastly, an integrated expression of IGF activity derived from one population significantly correlated with newborn BW in a geographically and culturally distinct population.

Body Mass Index↗
PubMed1996

Depth microhardness of glass ionomer cements.

The purpose of this study was to observe the effect of different conditions of storage on the surface and in the depth of luting glass ionomer cement by measuring microhardness. The hardness of a glass ionomer cement was measured after storage in wet and dry conditions and in an atmosphere of 80% relative humidity, for times up to 1000 h. Storage in distilled water produced a softening effect, but the depth hardness increased progressively. The penetration of the water is a surface phenomenon and does not affect the depth of the cement. However, the cement is vulnerable to moisture to a depth of 600 microns and marginal gaps evolve in the range of 40 to 80 microns when the luting cement at the tooth crown margin is always destroyed.

Biomechanical Phenomena↗
PubMed1996

An analysis of an axonal gradient of phosphorylated MAP 1B in cultured rat sensory neurons.

The present study investigated the cellular distribution of a developmentally regulated phosphorylated form of MAP 1B recognized by monoclonal antibody (mAb) 150 in cultures of dorsal root ganglia. The cell soma and the whole axon, when it first appears, are labelled, but longer axons label with a proximodistal gradient, such that the cell soma and proximal axon become unlabelled, whilst the distal axon and growth cone label strongly. Double-labelling experiments with mAb 150 and a polyclonal antibody (N1-15) that recognizes all forms of MAP 1B demonstrated that MAP 1B is distributed along the entire length of axons with gradients, so the gradient of phosphorylated MAP 1B is not due to a loss or absence of MAP 1B from the proximal axon. The proportion of axons from 20 h cultures that were labelled with a mAb 150 gradient was at least 80% and this proportion was independent of the nerve growth factor concentration of the culture medium. Analysis of axons ranging in length from 100 to 700 microm and labelled with a gradient showed that the unlabelled proximal portions of axons increased in length more slowly than the labelled distal axon. Axons labelled along their entire length accounted for no more than 19% of th axonal population and analysis of these showed them to be frequently < 400 microm long. After simultaneously fixing and detergent-extracting cultures this proportion rose significantly to 93%, suggesting that in the proximal axon the mAb 150 epitope is masked by some factor(s) that is removed by detergent extraction. The possibility that mAb 150 could not access the epitope in the proximal axon was discounted because another IgM, mAb 125, which recognizes a different phosphorylation epitope on MAP 1B, labelled the proximal axon of conventionally fixed cultures. In growth cones of fixed and extracted neurons examined by immunofluorescence, the mAb 150 labelling strongly colocalized to bundled microtubules in the distal axon shaft and the C-domain. In the P-domain, mAb 150 staining was weaker and more widely distributed than the microtubules. Immunogold electron microscopy confirmed that antibody N1-15 and mAb 150 strongly labelled the bundled microtubules in the C-domain and also showed that individual microtubules in the P-domain, some of which lie alongside actin filament bundles of filopodia, were labelled lightly and discontinuously with both antibodies. This suggests that the phosphorylated isoform of MAP 1B recognized by mAb 150 may be microtubules and actin filaments in the P-domain.

Animals↗
PubMed1995

Anti-syntaxin antibodies inhibit calcium-dependent catecholamine secretion from permeabilized chromaffin cells.

Adrenomedullary chromaffin cells release catecholamines in response to the intracellular calcium rise upon stimulation by different secretagogues. The presence of syntaxin 1, a protein presumably involved in docking of synaptic vesicles to presynaptic membranes, has been investigated in chromaffin cells. The study using two different monoclonal antibodies shows that syntaxin 1 is present in the chromaffin cell membrane fraction. Functional experiments demonstrate that anti-syntaxin antibodies inhibit calcium-dependent secretion in permeabilized cells. These results suggest that syntaxin 1 is an important component of the secretory machinery in chromaffin cells.

Adrenal Medulla↗
PubMed1995

Role of syntaxin in mouse pancreatic beta cells.

The role of syntaxin 1, a protein involved in the docking of synaptic vesicles at presynaptic active zones, has been investigated in pancreatic islet cells. Using two different monoclonal antibodies we have shown that syntaxin 1 is present in the pancreatic islet cell microsomal fraction. Furthermore, functional experiments demonstrate that anti-syntaxin antibodies inhibit CA(2+)-dependent insulin secretion in permeabilized islet cells. These data indicate that syntaxin 1 is present in the pancreatic beta cell and it is likely to play a functional role in the exocytosis of secretory granules.

Animals↗