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Biomedical subjects

F Martinez

Publications and source records attributed to F Martinez.

At least 37 records · Page 2Linked to original sources
PubMed2003

Iatrogenic Creutzfeldt-Jakob disease subsequent to dural graft: persisting risk after 1987.

The first case of Creutzfeldt-Jakob disease (CJD) related to the use of a dura mater graft of cadaveric origin was identified in 1987 and this procedure is now considered as one of the main causes of iatrogenic CJD. Although the decontamination procedure for the preparation of graft material was modified, the product was withdrawn from the market in many countries a few years later and replaced by synthetic material. In this context, two patients treated in our institution developed CJD following a cadaveric dural graft performed after cerebral and lumbar trauma. Their clinical presentation, showing predominant cerebellar symptoms, late deterioration and myoclonic jerks, and a rapid disease course until death, was similar to that of previously reported cases involving the iatrogenic form. As the graft for one of the patients was performed in 1991 (several years after modification of the decontamination procedure), this fourth reported case suggests that the risk of iatrogenic CJD may have persisted in some patients treated after 1987, when grafts of cadaveric origin were totally abandoned.

Adult↗
PubMed2003

Bullous scleroderma-like changes in chronic graft-versus-host disease.

Cutaneous graft-versus-host disease (GVHD) is the most common clinical setting for GVHD after bone marrow transplantation. Chronic cutaneous GVHD is categorized according to the type of skin lesions into lichenoid and sclerodermoid variants, but bullous scleroderma-like changes are exceptional. Recently, we studied a patient with these alterations. This is the second case described in the literature.

Adolescent↗
PubMed2003

Relationship between meiotic spindle location with regard to the polar body position and oocyte developmental potential after ICSI.

BACKGROUND: The recent development of a computer-assisted polarization microscopy system (Polscope) with which the meiotic spindle can be visualized in living oocytes on the basis of its birefringence permits analysis of the meiotic spindles of oocytes subjected to ICSI. Previous studies have shown that the meiotic spindle is not always aligned with the first polar body (PB) in metaphase II human oocytes prepared for ICSI. In the present study, the relationship between the degree of meiotic spindle deviation from the first PB location and ICSI outcome was analysed. METHODS: Oocytes were divided into four groups according to the angle of meiotic spindle deviation from the PB position. The angle of deviation was 0-5 degrees, 6-45 degrees, 46-90 degrees and >90 degrees for groups I to IV respectively. RESULTS: The rates of normal [2 pronuclei (PN)] and abnormal (1PN or >2PN) fertilization did not differ between groups I, II and III. However, the rate of normal fertilization was lower among oocytes in which the meiotic spindle deviation angle was >90 degrees; this led to an increased proportion of tripronucleated zygotes that failed to extrude the second PB. When embryos developed from normally fertilized oocytes were evaluated on day 3 after ICSI, no relationship was found between the angle of meiotic spindle deviation and embryo quality. The meiotic spindle was not detected in only 9% of oocytes, and these showed a higher incidence of fertilization and cleavage abnormalities than did oocytes in which the spindle was detected. When oocytes at metaphase I after cumulus oophorus and corona radiata removal were matured in vitro, the meiotic spindle was detected in 53.8% of those that reached metaphase II. In these in-vitro-matured oocytes the meiotic spindle was always aligned with the first PB, suggesting that misalignment seen in those oocytes matured in vivo resulted from PB displacement during manipulations for cumulus and corona removal. CONCLUSION: High degrees of misalignment between the meiotic spindle and the first PB predict an increased risk of fertilization abnormalities. However, when normal fertilization had occurred, the cleavage potential of embryos developing from such oocytes was not impaired. These findings facilitate the selection of oocytes for ICSI in situations when the creation of supernumerary embryos is to be avoided.

Cell Nucleus↗
PubMed2002

Topical use of cidofovir induced acute renal failure.

BACKGROUND: Cidofovir has antiviral activity against a wide spectrum of DNA viruses. Several small studies have focused on the efficacy of topical cidofovir in various viral-induced diseases. We report a systemic complication of such therapy. CASE REPORT: A bone marrow transplant recipient with chronic renal failure developed genital condylomas resistant to standard therapy. After topical cidofovir application (1% once daily for 5 days, then 4% for 12 days), the lesions improved while local erosions appeared. Acute renal failure with features of tubular acidosis occurred at day 19. Spontaneous recovery was observed after cidofovir withdrawal. CONCLUSION: We describe for the first time acute renal failure after topical cidofovir in an immunosuppressed patient with prior renal insufficiency. This method of administration should be avoided on abraded skin and should be carefully monitored.

Acute Kidney Injury↗
PubMed2002

A stereo-photogrammetric method to measure the facial dysmorphology of children in the diagnosis of fetal alcohol syndrome.

In diagnosing a child with fetal alcohol syndrome (FAS), anthropometric measurements of the face are conventionally performed by highly trained dysmorphologists using a hand-held ruler. This renders the screening of large populations of children for the facial features characteristic of FAS very time-consuming and costly. This study proposes a new, cost-effective, and non-intrusive method to measure in three dimensions the facial dysmorphology of children using stereo-photogrammetry. The face of each child is photographed in a control frame simultaneously by a pair of high-resolution digital cameras mounted 1.04 m from the child and 0.26 m apart. Software has been developed to calibrate the images and to compute the three-dimensional object-space coordinates of any point on the face from a measurement of the point on each of the images. The palpebral fissure lengths, inner canthal-, and interpupillary distances of 44 subjects were measured in this manner independently by two investigators and compared with measurements obtained by clinical specialists in the conventional manner. There was found to be no statistically significant difference between palpebral fissure lengths determined using the two techniques (paired Student's t-test p-values are 0.29 and 0.18, respectively). It has also been demonstrated that facial measurements can be performed with greater consistency from a pair of stereo photographs than direct measurements from live subjects.

Anthropometry↗
PubMed2002

Somatic and embryonic cell nucleus transfer into intact and enucleated immature mouse oocytes.

BACKGROUND: The aim of our study was to evaluate the possibility of embryonic or somatic cell haploidization after fusion with intact or enucleated immature oocytes which were subsequently cultured in vitro. Embryonic or somatic cell nuclei do not undergo premature chromosome condensation when fused to intact or enucleated immature oocytes whose maturation is prevented by dibutyryl cyclic AMP (dbcAMP). The presence of dbcAMP permits, however, the completion of DNA replication in somatic cell nuclei. METHODS AND RESULTS: The chromosomes condensed when the reconstructed cells were released from the dbcAMP block. When somatic or embryonic nuclei were introduced into intact immature meiotically competent oocytes and subsequently cultured their chromosomes assembled on a common spindle with meiotic chromosomes and proceeded through the meiotic-like division, judged according to the presence of the first polar body extruded. When embryonic cell nuclei were introduced into cytoplasts obtained from immature meiotically competent oocytes, polar bodies were extruded in about 75% of reconstructed cells but the metaphase plates were abnormal in almost all cases. When somatic cell nuclei were inserted into the above cytoplasts, polar bodies were extruded only very exceptionally and in these cells chromosomes were arranged in abortive metaphase plates. CONCLUSIONS: Our results suggest that somatic cell nuclei are unable to proceed through the reduction division (haploidization) when introduced into an immature oocyte meiotic cytoplasm.

Animals↗
PubMed2001

Metamorphic core complex formation by density inversion and lower-crust extrusion.

Metamorphic core complexes are domal uplifts of metamorphic and plutonic rocks bounded by shear zones that separate them from unmetamorphosed cover rocks. Interpretations of how these features form are varied and controversial, and include models involving extension on low-angle normal faults, plutonic intrusions and flexural rotation of initially high-angle normal faults. The D'Entrecasteaux islands of Papua New Guinea are actively forming metamorphic core complexes located within a continental rift that laterally evolves to sea-floor spreading. The continental rifting is recent (since approximately 6 Myr ago), seismogenic and occurring at a rapid rate ( approximately 25 mm yr-1). Here we present evidence-based on isostatic modelling, geological data and heat-flow measurements-that the D'Entrecasteaux core complexes accommodate extension through the vertical extrusion of ductile lower-crust material, driven by a crustal density inversion. Although buoyant extrusion is accentuated in this region by the geological structure present-which consists of dense ophiolite overlaying less-dense continental crust-this mechanism may be generally applicable to regions where thermal expansion lowers crustal density with depth.

Journal Article↗
PubMed2001

Laser-assisted intracytoplasmic sperm injection.

OBJECTIVE: To improve oocyte survival and fertilization rates after intracytoplasmic sperm injection (ICSI) in patients with inherent oocyte fragility. DESIGN: Pilot feasibility study and case report. SETTING: Private hospital. PATIENT(S): Infertile couple with repeated failures of ICSI caused by oocyte degeneration. INTERVENTION(S): Laser-assisted drilling of the zona pellucida followed by ICSI. MAIN OUTCOME MEASURE(S): Oocyte survival, fertilization, and pregnancy. RESULTS: In a couple with four previous ICSI failures because of poor oocyte survival (33.3%, 0%, 20%, and 18%), a fifth attempt using laser-assisted ICSI resulted in the survival of 8 oocytes out of 13 injected. Normal fertilization occurred in 5 oocytes, and a clinical pregnancy was established. CONCLUSION(S): Performing ICSI through a laser-drilled hole in the zona pellucida reduces the risk of oocyte damage related to deformation during the initial phase of the microinjection procedure. This modification of ICSI appears to be suitable for patients whose oocyte show inherent fragility and high degeneration rates after the standard ICSI procedure.

Adult↗
PubMed2001

Usual interstitial pneumonia.

Usual interstitial pneumonia (UIP) is a distinct histological lesion observed in idiopathic pulmonary fibrosis (IPF), but can be found in other etiologies. The diagnosis of UIP can be established by surgical lung biopsy or by high resolution thin section computed tomographic scans (provided the radiographic features are classical). Historically, patients labeled as "IPF'' encompassed a group of disorders including UIP as well as other idiopathic interstitial pneumonias, which differ from UIP in prognosis and responsiveness to therapy. Current recommendations from international consensus statements restrict the term IPF to patients with idiopathic UIP. The inciting cause(s) and pathogenesis of UIP have not been elucidated, but alveolar epithelial cell injury and dysregulation or altered phenotypic expression of fibroblasts are key elements. Inflammatory cells may play minor roles in initiating or propagating the fibrotic process. The prognosis of UIP is poor. Mean survival following diagnosis approximates 3 years. Current therapies are of unproven value. Corticosteroids or immunosuppressive agents have been most often used, but data affirming benefit are lacking. Single-lung transplantation is a viable option for patients failing medical therapy. Novel therapeutic strategies based upon inhibiting fibroproliferation or enhancing alveolar reepithelialization are desperately needed. In this article, we discuss diagnostic criteria for UIP (both histopathological and radiographic), natural history and clinical course, and therapeutic approaches (both current and future).

Journal Article↗
PubMed2001

CD14: a bridge between innate immunity and adaptive IgE responses.

Total IgE levels are known to be under genetic control. Linkage studies have indicated that one or more loci on chromosome 5q may control total IgE, as well as asthma and bronchial hyperresponsiveness to non-specific stimuli. Our group has undertaken a systematic analysis of chromosome 5q, and has recently characterized five single nucleotide polymorphisms at position -1619, -1359, -1145, -809, and -159 in the promoter of the gene encoding CD14, the myeloid pattern recognition receptor that is critical for efficient innate immune responses to lipopolysaccharide and bacterial ligands. Individuals homozygous for the three major CD14 haplotypes found in the Children Respiratory Study population (n = 390) were analyzed for serum levels of total IgE and soluble CD14. A strong inverse correlation was found between these two parameters, i.e. carriers of the -1359T/-1145A/-159C haplotype had the highest levels of IgE, and the lowest levels of sCD14. Conversely, carriers of the -1359G/-1145G/-159T haplotype had the highest levels of sCD14 and the lowest IgE values. Our results suggest that genetic variation in CD14, a key gene of innate immunity, may modulate the effects that exposure to bacterial ligands has on the development of Th2 responses.

Child↗
PubMed2001

Novel heterogeneous catalysts in the wet peroxide oxidation of phenol.

Catalytic wet peroxide oxidation (CWPO) of diluted aqueous solutions of phenol has been studied over a series of heterogeneous catalysts at 100 degrees C under 1 MPa air pressure. Several catalysts were prepared and tested including zeolitic materials exchanged with metallic ions such as Fe and Cu and different mixed oxides. Likewise, a Fe-TS-1 zeolite was synthesised by isomorphous substitution of Si atoms by Fe and Ti into the MFI zeolitic framework through hydrothermal synthesis of wetness-impregnated Fe2O3-TiO2-SiO2 xerogels. This material showed a complete phenol removal and TOC reduction of up to 68% under the reaction conditions, with a low leaching of iron species as compared to Fe-exchanged zeolitic materials. Perovskite of type LaTi(0.45)Cu(0.55)O3 was also tested, showing copper leaching of 22%, with a TOC conversion of 93% and total phenol removal. The capacity of Fe and Cu containing catalysts to promote free radicals in the presence of H2O2 as well as the thermal decomposition of the oxidant under the reaction conditions have also been studied. In the absence of hydrogen peroxide, Fe and Cu catalysts were not effective in order to decrease TOC content.

Calcium Compounds↗