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Biomedical subjects

L Cardenas

Publications and source records attributed to L Cardenas.

11 recordsLinked to original sources
PubMed2007

Transcatheter closure of secundum atrial defect in small children.

OBJECTIVE: To assess safety and efficacy of transcatheter atrial septal defect (ASD) closure in small children. BACKGROUND: Percutaneous closure of ASD is a well accepted alternative to surgery. Reported experience in small children remains, however, scarce. METHODS: Fifty-two children underwent percutaneous ASD closure at a weight < or =15 kg, in four Belgian tertiary referral paediatric cardiology centers. Indication for treatment, device implantation rate, procedural details, complication rate, residual shunt on echocardiography, and impact of procedure on symptoms were retrospectively analyzed. RESULTS: Mean age at procedure was 36 months (7-60), mean weight 13 kg (4.7-15). Associated cardiac lesions were seen in 21% of the patients and noncardiac in 32.7%. Most patients (69.2%) were symptomatic. Mean ASD size was 12 mm (range 5-20 mm). A device could be inserted in 49 patients (94%). No major complications occurred. Minor complications occurred in 8 patients (15.4%) including device embolization in 2, successfully treated with transcatheter retrieval and second device insertion. Mean follow-up reached 27 months (0.03-61.2). Residual shunt was absent, trivial, or small in 93% (n = 42) at latest follow-up. Clinical improvement was noted in 91.7% of the symptomatic patients. Minor complications were more frequent in the presence of large ASDs (>15 mm) but not in smaller babies (<10 kg). CONCLUSION: Patients < or =15 kg requiring ASD closure form a special population with high incidence of associated anomalies and medical conditions. For this particular set of patients, percutaneous closure is a valid alternative. Asymptomatic or mildly symptomatic children should be treated at a later age.

Belgium↗
PubMed2006

Targeted expression of csCSF-1 in op/op mice ameliorates tooth defects.

OBJECTIVE: The aim of this study was to characterize the tooth phenotype of CSF-1-deficient op/op mice and determine whether expression of csCSF-1 in these mice has a role in primary tooth matrix formation. DESIGN: Ameloblasts and odontoblasts, isolated from wt/wt frozen sections using laser capture microdissection, were analysed for csCSF-1, sCSF-1 and CSF-1R mRNA by RT-PCR. Mandibles, excised from 8 days op/op and wt/wt littermates, were examined for tooth morphology as well as amelogenin and DMP1 expression using in situ hybridisation. op/opCS transgenic mice, expressing csCSF-1 in teeth and bone using the osteocalcin promoter, were generated. Skeletal X-rays and histomorphometry were performed; teeth were analysed for morphology and matrix proteins. RESULTS: Normal dental cells in vivo express both CSF-1 isoforms and CSF-1R. Compared to wt/wt, op/op teeth prior to eruption showed altered dental cell morphology and dramatic reduction in DMP1 transcripts. op/opCS mice showed marked resolution of osteopetrosis, tooth eruption and teeth that resembled amelogenesis imperfecta-like phenotype. At 3 weeks, op/op teeth showed severe enamel and dentin defects and barely detectable amelogenin and DMP1. In op/opCS mice, DMP1 in odontoblasts increased to near normal and dentin morphology was restored; amelogenin also increased. Enamel integrity improved in op/opCS, although it was thinner than wt enamel. CONCLUSIONS: Results demonstrate that ameloblasts and odontoblasts are a source and potential target of CSF-1 isoforms in vivo. Expression of csCSF-1 within the tooth microenvironment is essential for normal tooth morphogenesis and may provide a mechanism for coordinating the process of tooth eruption with endogenous matrix formation.

Ameloblasts↗
PubMed2005

Upper limits on a stochastic background of gravitational waves.

The Laser Interferometer Gravitational-Wave Observatory has performed a third science run with much improved sensitivities of all three interferometers. We present an analysis of approximately 200 hours of data acquired during this run, used to search for a stochastic background of gravitational radiation. We place upper bounds on the energy density stored as gravitational radiation for three different spectral power laws. For the flat spectrum, our limit of omega0 < 8.4 x 10(-4) in the 69-156 Hz band is approximately 10(5) times lower than the previous result in this frequency range.

Journal Article↗
PubMed2005

Limits on gravitational-wave emission from selected pulsars using LIGO data.

We place direct upper limits on the amplitude of gravitational waves from 28 isolated radio pulsars by a coherent multidetector analysis of the data collected during the second science run of the LIGO interferometric detectors. These are the first direct upper limits for 26 of the 28 pulsars. We use coordinated radio observations for the first time to build radio-guided phase templates for the expected gravitational-wave signals. The unprecedented sensitivity of the detectors allows us to set strain upper limits as low as a few times 10(-24). These strain limits translate into limits on the equatorial ellipticities of the pulsars, which are smaller than 10(-5) for the four closest pulsars.

Journal Article↗
PubMed2003

Acceptability of manual versus electric aspiration for first trimester abortion: a randomized trial.

This study was conducted to compare the acceptability of manual and electric vacuum aspiration for first trimester elective abortion. Eighty-four women seeking abortions at less than 10 weeks gestation were randomized to abortion by manual or electric vacuum aspiration. Post-procedure questionnaires were administered to patients to assess pain, noise disturbance and overall satisfaction with the abortion procedure. Physicians reported procedural difficulty, their perceptions of patient discomfort and their overall acceptance of the procedure. Other outcomes included amounts of anesthesia required and complication rates. There were no significant differences in pain levels or satisfaction reported by patients; however, significantly more women in the electric group were bothered by noise (19% vs. 2%, p = 0.03). There were no differences in physician assessments of procedural difficulty; however, there were significantly more times in the electric group that physicians would have preferred manual aspiration (43% vs. 17%, p = 0.02). There were four crossovers from manual to electric, and none from electric to manual. It is concluded that physicians and patients find manual vacuum aspiration as acceptable as electric vacuum aspiration for elective abortions performed at less than 10 weeks gestation.

Abortion, Induced↗
PubMed1999

Idiopathic condylar resorption: diagnosis, treatment protocol, and outcomes.

Idiopathic condylar resorption is a poorly understood progressive disease that affects the TMJ and that can result in malocclusion, facial disfigurement, TMJ dysfunction, and pain. This article presents the diagnostic criteria for idiopathic condylar resorption and a new treatment protocol for management of this pathologic condition. Idiopathic condylar resorption most often occurs in teenage girls but can occur at any age, although rarely over the age of 40 years. These patients have a common facial morphology including: (1) high occlusal and mandibular plane angles, (2) progressively retruding mandible, and (3) Class II occlusion with or without open bite. Imaging usually demonstrates small resorbing condyles and TMJ articular disk dislocations. A specific treatment protocol has been developed to treat this condition that includes: (1) removal of hyperplastic synovial and bilaminar tissue; (2) disk repositioning and ligament repair; and (3) indicated orthognathic surgery to correct the functional and esthetic facial deformity. Patients with this condition respond well to the treatment protocol presented herein with elimination of the disease process. Two cases are presented to demonstrate this treatment protocol and outcomes that can be achieved. Idiopathic condylar resorption is a progressive disease that can be eliminated with the appropriate treatment protocol.

Adolescent↗
PubMed1999

Rhizobium nod factors induce increases in intracellular free calcium and extracellular calcium influxes in bean root hairs

Application of Nod factors to growing, responsive root hairs of the bean Phaseolus vulgaris induces marked changes in both the intracellular cytosolic free calcium (Ca2+) and in the influx of extracellular [Ca2+]. The intracellular [Ca2+], which has been measured by ratiometric imaging in cells microinjected with fura-2-dextran (70 kDa), elevates within 5 min from approximately 400 nM to 1500 nM in localised zones in the root hair apex. Of particular note is the observation that the elevated regions of [Ca2+] appear to shift position during short time intervals. Increases in and fluctuations of the intracellular [Ca2+] are also observed in the perinuclear region after 10-15 min treatment with Nod factors. The extracellular Ca2+ flux, detected with the non-invasive, calcium specific vibrating electrode, is inwardly directed and also increases quickly in response to Nod factors from 13 pmol cm-2 s-1 to 28 pmol cm-2 s-1. Chitin-oligomers, which are structurally similar but biologically inactive when compared to the active Nod factors, fail to elicit changes in either intracellular or extracellular Ca2+. The similar timing and location of the intracellular elevations and the increased extracellular influx provide support for the idea that Ca2+ participates in secretion and cell wall remodelling, which occur in anticipation of root hair deformation and curling.

Journal Article↗
PubMed1997

Evaluation of immunogenicity of an oral Salmonella vaccine expressing recombinant Plasmodium berghei merozoite surface protein-1.

A repetitive region of Plasmodium berghei merozoite surface protein-1 (PbMSP-1) was expressed as a fusion protein with either maltose binding protein or the B subunit of heat-labile enterotoxin from Escherichia coli. Vaccination of mice with the fusion proteins indicates that this region of PbMSP-1 is antigenic as evidenced by an antibody response. The fusion proteins were also expressed in Salmonella and mice were orally immunized with the recombinant Salmonella. Some of the vaccinated mice survived a challenge with P. berghei blood-stage parasites without developing parasitemia. All control mice became patent and succumbed to the challenge infection. This partial protection was also observed with purified recombinant protein and was independent of the adjuvant used. Mice immunized with recombinant Salmonella showed either extremely low or no antibody response to PbMSP-1, suggesting that cell-mediated immunity is important for the observed protection. These studies show that it is feasible to develop a cost effective oral vaccine against the blood stage of the malarial parasite.

Administration, Oral↗
PubMed1990

Phosphorylation-dephosphorylation of the CD6 glycoprotein renders two isoforms of 130 and 105 kilodaltons. Effect of serum and protein kinase C activators.

The molecular nature of the structural changes on the T cell-CD6 glycoprotein upon cell activation has been investigated. Cell surface 125I labeling and immunoprecipitation studies from PBMC revealed that after stimulation by different activators of protein kinase C, or after exposure to either human or FCS, the anti-CD6 mAb precipitated an additional protein of 130 kDa, together with the 105-kDa protein present in resting cells. Cell surface expression of this 130-kDa CD6 protein form could be detected as early as 15 min after PKC activation, without requiring de novo protein synthesis. Pulse and chase activation experiments of radioiodinated cells suggested that the 130-kDa molecule is the result of a posttranslational modification of the 105-kDa protein and that this conversion is a reversible process. Studies of 32P-cell labeling and immunoprecipitation by anti-CD6 mAb revealed that only the 130-kDa form was phosphorylated, whereas the 105-kDa protein was unphosphorylated both in resting and activated cells. Moreover, the removal of phosphate groups from the 130-kDa CD6-form by enzymatic treatment with alkaline phosphatase resulted in its conversion to the 105-kDa form. Taken together, these results demonstrate the existence of two CD6 molecular forms that are in a dynamic equilibrium and differ only at their degree of phosphorylation: a 105-kDa unphosphorylated form present in resting T cells that changes very rapidly to a 130-kDa phosphorylated form by exposure of cells either to serum or to activators of PKC.

Antibodies, Monoclonal↗