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Biomedical subjects

C Fernandez

Publications and source records attributed to C Fernandez.

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

[Review of quality of life instruments used in end-stage renal disease].

Health related quality of life (HRQOL) indicators take into account the personal perception of health, and are proposed as an alternative for efficacy indicators in medical and therapeutic decision making. They provide, due to elaboration and validation of a questionnaire, a standardised assessment of the health status perception. This paper provides a review of a variety of HRQOL instruments developed for patients suffering end-stage renal disease (ESRD). Generic instruments are designed to be applicable in general population and disease-targeted instrument are potentially more sensitive to the characteristics of a specific population. Among HRQOL instruments, we found 4 generic questionnaires (the Sickness Impact Profile, the SF 36, the Nottingham Health Profile and the EQ-5D), 3 disease-targeted questionnaires developed for ESRD patient undergoing dialysis (the Kidney Disease Quality of Life instrument, the Kidney Disease Questionnaire and the Choice Health Experience Questionnaire), 1 questionnaire specific for ESRD patients (the HRQOL questionnaire), and 2 specific disease-targeted instruments for renal transplant (the Kidney Transplant Questionnaire and the ESRD Symptom Checklist-Transplantation Module). In France, very few studies on the quality of life of ESRD patients were published; no specific questionnaire validated in French is yet published.

Humans↗
PubMed2002

Pituicytomas, a mis-diagnosed benign tumor of the neurohypophysis: report of three cases.

Pituicytoma is a rare benign primary tumor of the neurohypophysis, occurring in the sellar and suprasellar spaces. We report here three new cases with immunohistochemical and electron microscopic study. Particular attention was paid to the expression of some cell adhesion molecules. These tumors were characterized by bundles of elongated cells strongly immunoreactive to anti-vimentin, S-100 protein, neural cell adhesion molecule and neuron-specific enolase antibodies. Glial fibrillary acidic protein (GFAP) was not recorded. It expressed the very late antigen alpha2 (VLAalpha2), but not VLAalpha5, and lacked epithelial markers expression (epithelial membrane antigen, E-cadherin), and specific neuronal markers (synaptophysin, chromogranin, neurofilament). Staining for pituitary hormones was negative. At the ultrastructural level, tumor/blood vessel basal lamina and cytoplasmic intermediate filaments were observed but desmosome or pericellular basal lamina were lacking. In one case few secretory granules were recorded. Differential diagnoses include granular cell tumors, pilocytic astrocytomas and spindle cell tumors such as solitary fibrous tumors, fibroblastic meningiomas and schwannomas. However, the unique pattern of antigenic expression and ultrastructural features of pituicytomas distinguish this rare tumor. As a subpopulation of pituicytes (which are distinctive glial cells of the neurophypophysis), some pituicytomas do not expressed GFAP. This suggests that pituicytomas presumably arise from pituicytes at various stages of their differentiation.

Astrocytoma↗
PubMed2002

Benzophenone-3: rapid prediction and evaluation using non-invasive methods of in vivo human penetration.

The study described in this paper constitutes a practical assay system to evaluate in vivo drug penetration using two complementary non-invasive methods. An electrical capacitance test was first applied to the skin on the forearm to evaluate the hydration of the skin, and check the integrity of the stratum corneum. In the first step, the percentage absorption was measured using an occlusive and difference method; following benzophenone-3 application any residual formulation was washed off and the amount removed analyzed. In the second step, the tape stripping method-a useful procedure for selectively removing the skin's outermost layer, the stratum corneum, and measuring the stratum corneum adsorption-was performed. Under these conditions the human skin permeation of this UV-filter over four hours was near to 35% of the applied dose with the occlusive method. The amount of topically applied benzophenone-3 found in the stratum corneum after 30 min exposure using the stripping procedure was evaluated at 4% to the applied dose.

Adult↗
PubMed2002

A protein from the cabbage looper, Trichoplusia ni, regulated by a bacterial infection is homologous to 3-dehydroecdysone 3beta-reductase.

During the screening of immune-regulated genes from the cabbage looper, Trichoplusia ni, a 3-dehydroecdysone 3beta-reductase homologue (DERH) was cloned. In the course of development, 3-dehydroecdysone 3beta-reductase mediates the conversion of 3-dehydroecdysone (3dE) secreted from the prothoracic glands to ecdysone (E), which is subsequently converted to 20-hydroxyecdysone (20E), the major insect molting hormone. The cloned gene is upregulated in fat body during development and is strongly induced after the larva is challenged with bacteria. The gene codes for a 308 amino acid residue protein which shows 42.5% identity to Spodoptera littoralis 3-dehydroecdysone 3beta-reductase. Using the baculovirus expression system, the recombinant DERH was expressed. The purified protein mediates the reduction of 3-dehydromakisterone A to makisterone A, and requires NADPH as a cofactor. Western blots using an antiserum to T. ni DERH revealed the presence of the protein in larval hemolymph and integument. The data indicate that the protein is regulated developmentally and is induced after a challenge with bacteria. Immunohistochemical studies localized the enzyme exclusively in the epidermis and the cuticle.

3-Hydroxysteroid Dehydrogenases↗
PubMed2002

Fatal amniotic fluid embolism diagnosed histologically.

Although the mortality of amniotic fluid embolism remains very high, there are more and more reports of patients surviving after prompt and aggressive therapy. However its pathogenesis is controversial, and, in some cases, an anaphylactic reaction to the amniotic fluid rather than the hemodynamic changes following mechanical obstruction by an embolus has been proposed as the underlying pathophysiological mechanism. In this paper we describe a case of amniotic fluid embolism with florid clinical features and a difficult and delayed diagnosis. On autopsy, clear-cut histological changes of amniotic fluid embolism were found.

Adult↗
PubMed2002

Congenital disseminated malignant rhabdoid tumor and cerebellar tumor mimicking medulloblastoma in monozygotic twins: pathologic and molecular diagnosis.

Malignant rhabdoid tumors are highly aggressive childhood tumors. Recently, all of the malignant rhabdoid tumors, whatever their location, have been related to the inactivation of the hSNF5/INI1 gene. A subset of cerebral tumors, associated with malignant rhabdoid tumors or isolated ones arising in siblings, showed similar molecular alterations. We report for the first time in monozygotic twins a congenital disseminated malignant rhabdoid tumor in one twin and a cerebellar tumor mimicking a medulloblastoma in the other. Molecular analysis revealed similar alterations for both tumors: a deletion of exon 7 of the hSNF5/INI1 gene in one allele, and a point mutation in the same exon in the other, suggesting a common genetic pathway. Analysis of constitutional DNA revealed a germline mutation. These findings are in favor of a common etiology for rhabdoid tumor and a subset of brain tumors developing in infancy.

Biomarkers, Tumor↗
PubMed2002

Combined orthogeriatric care in the management of hip fractures: a prospective study.

AIMS: To evaluate the efficacy of combined care between orthopaedic surgeons and geriatricians in the management of patients with fractured necks of femur. PATIENTS AND METHODS: A prospective study of the admissions to a district general hospital with hip fractures was carried out over a 5-year period. In the years 1992-1994, medical problems in this patient group were managed by a consultation-only service. At the end of 1994, a consultant geriatrician was appointed to manage these patients jointly with the orthopaedic surgeons, and the study was then carried through until the end of 1996. Information about the patients from admission to discharge or death was gathered prospectively using a proforma for the 3 years prior to orthogeriatric care, and the 2 years after. Main outcome measures were mortality, length of stay and discharge destination. These were compared for the two periods--pre- and post-orthogeriatric care. RESULTS: No significant differences were noted in mortality, length of stay or discharge destination. CONCLUSIONS: Combined orthogeriatric care according to our model did not have an impact on our chosen outcome measures.

Aged↗
PubMed2002

[Dermatomyositis and polymyositis].

Dermatomyositis (DM) and polymyositis (PM) are the two main forms of idiopathic inflammatory myopathies. They have in common a proximal muscle weakness, but skin manifestations, juvenile forms and increased incidence of malignancies are clinical characteristics of DM. The follow up of creatine-kinases is the best biological test in spite of their possible normality. The significance of antibodies titers is uncertain, except the association Jo-1 interstitial and lung disease indicating a poor prognosis. The association with HLA haplotypes expresses a genetic predisposition of a dysimmunity to develop DM or PM. Pathological changes are well known with a humoral immune effector mechanism in DM, and a muscle fibre aggression by CD8 + T cells in PM. Non inflammatory forms of DM and PM and rhabdomyolytic forms of PM are not very rare, they are recognized by the HLA class 1 immunoreactivity. Pathophysiological processes involve muscle fibers, inflammatory cells and endothelial cells of capillaries, with a complex intervention of cytokines, adhesion molecules, MHC classe 1, membrane attack complex, anti endothelial cells antibodies, perforin secretion and sometimes apoptotic Fas-mediated mechanisms. Despite these recent advances, causal antigens and activator processes of endothelial cell lysis and autoinvasive cytotoxicity of muscle fibers remain to be identified.

Biomarkers↗
PubMed2001

Colchicine myopathy: a vacuolar myopathy with selective type I muscle fiber involvement. An immunohistochemical and electron microscopic study of two cases.

Colchicine, a microtubule polymerization inhibitor, can very occasionally induce myopathy. We report two cases of colchicine myopathy. Both patients presented with myalgia and proximal muscle weakness. The first patient, an 80-year-old woman, had chronic renal failure related to renal amyloidosis. She had been treated by colchicine for 4 months. The second, a 75-year-old man with normal renal function, suffering from gout, was treated by colchicine for 3 weeks. Muscle biopsies displayed the same alterations, but the degree of severity was different. Conventional histology revealed vacuolar changes characterized by acid phosphatase-positive vacuoles and myofibrillar disarray foci. The lesions were selective for type I fibers. Ultrastructural study demonstrated autophagic vacuoles. Most of the vacuoles expressed dystrophin but not merosin. Several fibers reacted with anti-MHC class I antibody and granular deposits of membrane attack complex were observed on the surface of numerous myofibers. Anti-alphaB-crystallin antibody strongly reacted with vacuolar content. Physiopathologically, microtubules are primordial for vesicle movements and colchicine induces autophagic vacuole accumulation by preventing their fusion with lysosomes. The selective type I involvement is probably due to the higher tubulin amount in type I fibers. AlphaB-crystallin overexpression is related to its microtubule protection properties. Moreover, we suggest that vacuoles randomly floating in sarcoplasm might occasionally meet the plasma membrane and open in the extracellular space, leading to complement activation. Accurate diagnosis of colchicine myopathy is relevant because the treatment is based on colchicine interruption.

Aged↗
PubMed2001

Mobilization and collection of peripheral blood CD34+ cells from patients with Fanconi anemia.

A potential therapeutic option for patients with Fanconi anemia is collection of peripheral blood stem cells prior to the development of severe pancytopenia. These hematopoietic cells potentially could be infused when symptomatic bone marrow failure develops, as autologous rescue after chemotherapy in the event of leukemic transformation, or as targets for gene therapy. Eight patients with Fanconi anemia were mobilized with 10 microg/kg per day of granulocyte colony-stimulating factor (median, 10 +/- 4 days) to determine the feasibility of collecting peripheral blood stem cells for future use. Six patients achieved a peripheral blood CD34+ count of > or = 6/microL and underwent apheresis. The collection goal was 2 x 10(6) CD34+ cells/kg based on a predicted weight 5 years from the date of collection. A mean of 2.6 +/- 0.9 x 10(6) CD34+ cells/kg of the weight at the time of collection were collected, which corresponded to 1.9 +/- 0.4 x 10(6) CD34+ cells/kg of the target weight. The collections required a mean of 4 +/- 3 days (range, 2-8 days) of apheresis. Six of the 8 subjects had > or = 1 x 10(6) CD34+ cells/kg cryopreserved based on both actual and target weights, and 4 subjects had > or = 2 x 10(6) CD34+ cells/kg cryopreserved based on the target weight. These results suggest that some patients with Fanconi anemia can have adequate numbers of CD34+ cells mobilized and collected from the peripheral blood prior to the onset of severe bone marrow failure, but they may require an extended mobilization and multiple days of collection.

Adolescent↗
PubMed2001

Mechanisms of pulmonary gas exchange improvement during a protective ventilatory strategy in acute respiratory distress syndrome.

To investigate the mechanisms underlying improvement of arterial oxygenation during a protective ventilatory strategy (PVS) in early acute respiratory distress syndrome (ARDS), we studied eight patients during volume-controlled mechanical ventilation, keeping respiratory rate and fraction of inspired oxygen (FI(O(2))) (0.82 +/- 0.20) unchanged: (1) at baseline (tidal volume [VT] 10 to 12 ml x kg(-1); positive end-expiratory pressure [PEEP] 8 to 10 cm H(2)O); (2) during PVS (PEEP 2 cm H(2)O above the low inflexion point (P(FLEX)) and VT of 5 to 7 ml x kg(-1)); and (3) post-PVS, back to baseline conditions. Inert gas measurements were done after 30 min in each ventilatory modality. During PVS, Pa(O(2)) increased significantly from 93 +/- 27 to 166 +/- 77 mm Hg (p < 0.008) and Pa(CO(2)) rose from 39 +/- 7 to 57 +/- 11 mm Hg (p < 0.0002) because of the decrease in minute ventilation (V E) (-3.6 L x min(-1)) (p < 0.005). Both heart rate (HR, +13 min(-1)) (p < 0.002) and cardiac output (Q, +1.2 L x min(-1)) (p < 0.05) increased. Static respiratory system linear compliance increased from 36 +/- 14 to 44 +/- 16 ml. cm H(2)O(-1) (p < 0.0002). PVS provoked recruitment of previously collapsed alveoli and redistribution of pulmonary blood flow from nonventilated alveoli to normal lung. Despite the increase in Q, intrapulmonary shunt fell from 39 +/- 15% to 31 +/- 11% (p < 0.04). We conclude that the decrease in intrapulmonary shunt owing to alveolar recruitment remains the pivotal mechanism to explain improvement of arterial oxygenation during this PVS.

Adult↗
PubMed2001

Absence of Mn-centered oxidation in the S(2) --> S(3) transition: implications for the mechanism of photosynthetic water oxidation.

A key question for the understanding of photosynthetic water oxidation is whether the four oxidizing equivalents necessary to oxidize water to dioxygen are accumulated on the four Mn ions of the oxygen-evolving complex (OEC), or whether some ligand-centered oxidations take place before the formation and release of dioxygen during the S(3) --> [S(4)] --> S(0) transition. Progress in instrumentation and flash sample preparation allowed us to apply Mn Kbeta X-ray emission spectroscopy (Kbeta XES) to this problem for the first time. The Kbeta XES results, in combination with Mn X-ray absorption near-edge structure (XANES) and electron paramagnetic resonance (EPR) data obtained from the same set of samples, show that the S(2) --> S(3) transition, in contrast to the S(0) --> S(1) and S(1) --> S(2) transitions, does not involve a Mn-centered oxidation. On the basis of new structural data from the S(3)-state, manganese mu-oxo bridge radical formation is proposed for the S(2) --> S(3) transition, and three possible mechanisms for the O-O bond formation are presented.

Electron Spin Resonance Spectroscopy↗
PubMed2001

Ab initio structure determination of a small-pore framework sodium stannosilicate.

The structure of a small-pore framework sodium stannosilicate Na(2)SnSi(3)O(9).2H(2)O (AV-10) has been determined ab initio from powder X-ray diffraction data (XRD). The unit cell is orthorhombic (space group C222(1), Z = 4) with cell dimensions a = 7.9453(5), b = 10.3439(7), c = 11.6252(7) A, V = 955 A(3). The structure of AV-10 is composed of corner sharing SnO(6) octahedra and SiO(4) tetrahedra, forming a three-dimensional framework structure. The SiO(4) tetrahedra form helix chains along [001] interconnected by SnO(6) octahedra. The SnO(6) octahedra are isolated by SiO(4) tetrahedra and, thus, there are no Sn-O-Sn linkages. AV-10 has been characterized by chemical analysis, powder XRD, scanning electron microscopy, (29)Si, (119)Sn, single- and (FAM) triple-quantum (23)Na MAS NMR spectroscopy, thermogravimetry (TGA), and nitrogen adsorption isotherms. The zeolitic water of AV-10 is reversibly lost. The dehydrated material has been studied in situ by powder XRD, TGA, and, in particular, triple-quantum (23)Na MAS NMR.

Journal Article↗
PubMed2001

Intestinal absorption and metabolism of chlorpheniramine enantiomers in rat.

Chlorpheniramine (CPAM) is a chiral antihistaminic drug commercialized as a racemic mixture. The intestinal absorption and metabolism of CPAM have been investigated in rat using in vivo (oral and IV administration), in situ (intestinal loop model), and in vitro (everted sac model) experiments. Oral and IV administrations of 20 mg/kg of the racemic mixture show that the pharmacokinetics of CPAM are stereoselective, with higher AUCs for the (+)-S-enantiomer compared to its antipode. The monodesmethyl metabolite (DCPM) was quantifiable in blood and its pharmacokinetics are stereoselective after oral but not after IV administration. Experiments using intestinal loops and everted sacs showed that the absorption is not stereoselective and that in vivo stereoselective formation of DCPM is presumably due to stereoselective hepatic metabolism. Moreover, the in vitro and in situ absorption of CPAM are not modified by modulators of P-glycoprotein and cytochromes P450 (cyclosporin A, ketoconazole).

Animals↗
PubMed2001

Characterization of the methylation-sensitive promoter of the imprinted ZAC gene supports its role in transient neonatal diabetes mellitus.

ZAC is a recently isolated zinc finger protein that induces apoptosis and cell cycle arrest. The corresponding gene is imprinted maternally through an unknown mechanism and maps to 6q24-q25, within the minimal interval harboring the gene responsible for transient neonatal diabetes mellitus (TNDM) and a tumor suppressor gene involved in breast cancer. Because of its functional properties, imprinting status, and expression pattern in mammary cell lines and tumors, ZAC is the best candidate so far for both disease conditions. In the present work, we delineated ZAC genomic organization and mapped its transcriptional start site. It is noteworthy that the ZAC promoter localized to the CpG island harboring the methylation imprint associated with TNDM and methylation of this promoter silenced its activity. These data indicate that the methylation mark may have a direct effect on the silencing of the ZAC imprinted allele. Our findings further strengthen the hypothesis that ZAC is the gene responsible for TNDM and suggest a novel mechanism for ZAC inactivation in breast tumors.

Alleles↗
PubMed2001

Comparison of elderly people's technique in using two dry powder inhalers to deliver zanamivir: randomised controlled trial.

OBJECTIVE: To determine whether elderly people can learn to use the inhaler used to deliver zanamivir (Relenza Diskhaler) as effectively as the Turbohaler and to identify which aspects of inhaler technique are most problematic. DESIGN: Randomised, controlled, intervention study. SETTING: Wards for acute elderly care in a large district general hospital. PARTICIPANTS: 73 patients who were unfamiliar with the use of an inhaler, aged 71 to 99 (mean 83) years. MAIN OUTCOME MEASURES: Initial scores and changes in scores 24 hours later using a 10 point scoring system of five aspects of inhaler technique. RESULTS: 38 patients were allocated the Relenza Diskhaler and 35 the Turbohaler. The mean total score was significantly greater in the Turbohaler than Diskhaler groups both initially (8.74 v 7.05) and after 24 hours (8.28 v 5.43). The major difference between inhalers was in loading and priming. After tuition 50% (19 of 38) of patients allocated the Diskhaler were unable to load and prime the device and 65% (24 of 37) were unable to do so 24 hours later. Of those allocated the Turbohaler, two patients were unable to load and prime the device after initial review and one after 24 hours. CONCLUSION: Most elderly people cannot use the inhaler device used to deliver the anti-influenza drug zanamivir. Treatment with this drug is unlikely to be effective in elderly people unless the delivery system is improved.

Administration, Inhalation↗