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Biomedical subjects

S Fernandez

Publications and source records attributed to S Fernandez.

At least 19 recordsLinked to original sources
PubMed2006

Physician handwashing: what do parents want?

Transmission of micro-organisms from the hands of healthcare workers to patients is a major cause of healthcare-acquired infections. In 2002, the US Centers for Disease Control and Prevention (CDC) published guidelines for healthcare workers that included the recommendation for alcohol-based hand rub for hand hygiene during patient visits. In this prospective study we surveyed parental and healthcare workers' preferences for the hand hygiene practices of emergency physicians. The study comprised 99 parents of ill or injured children presenting to our emergency department and 100 healthcare providers (64 nurses, 29 physicians and seven nurse practitioners) within the department. There was a clear and similar preference by parents and healthcare workers for hand hygiene using soap and water over alcohol cleansing rubs. Furthermore, both groups preferred hand hygiene before and after the examination and wanted to observe the physician perform this procedure. In conclusion, families and healthcare worker preferences for hand hygiene are not in keeping with recommendations published by the CDC. Educational interventions are needed to disseminate the CDC's guidelines and to promote compliance with evidence-based recommendations for hand hygiene.

Adult↗
PubMed2006

Middle cerebral artery pulsatility index: reliability at different sampling sites.

OBJECTIVES: To analyze the interobserver reliability of measurement of the middle cerebral artery (MCA) pulsatility index (PI) at two different sampling sites. METHODS: This study included 100 consecutive singleton pregnancies between 24 and 40 weeks with normal fetal growth. The PI was calculated by two independent operators at proximal and distal sampling sites of the near-field MCA. Reliability analyses were performed between observers at each sampling site by means of the intraclass correlation coefficient (ICC) for agreement. Differences between observers were explored and agreement limits calculated by means of the Bland-Altman test. RESULTS: Satisfactory flow velocity waveforms were obtained successfully in each fetus at both sampling sites. Peak systolic, end-diastolic and time-averaged maximum velocities were significantly higher at the proximal compared with the distal sampling site. Conversely, PI was significantly higher at the distal compared with the proximal site. ICCs for PI were 0.3 and 0.33 at the proximal and the distal sampling sites, respectively. The 95% interval of the PI differences between observers were +0.91 and -1.14 at the proximal and +1.03 and -1.08 at the distal sampling sites. In about 30% of the cases the PI difference between observers was greater than 0.5 at both sampling sites. CONCLUSIONS: Moderate interobserver reliability in the measurement of end-diastolic and time-averaged maximum MCA flow velocities results in limited agreement of the PI calculation at both proximal and distal sampling sites. These results may preclude its clinical applicability.

Adolescent↗
PubMed2003

[Can nomograms derived in the U.S. applied to German patients? A study about the validation of preoperative nomograms predicting the risk of recurrence after radical prostatectomy].

In patients suffering from prostate cancer, preoperative nomograms, which predict the risk of recurrence may provide a helpful tool in regard to the counselling and planning of an appropriate therapy. The best known nomograms were published by the Baylor College of Medicine, Houston and the Harvard Medical School, Boston. We investigated these nomograms derived in the U.S. when applied to German patients. Data from 1003 patients who underwent radical prostatectomy at the University-Hospital Hamburg were used for validation. Nomogram predictions of the probability for 2-years (Harvard nomogram) and 5-years (Kattan nomogram) freedom from PSA recurrence were compared with actual follow-up recurrence data using areas under the receiver-operating-characteristic curves (AUC). The recurrence free survival after 2 and 5 years was 78% and 58%, respectively. The AUC of the Harvard nomogram predicting 2-years probability of freedom from PSA recurrence was 0.80 vs. Kattan-Nomogram 5-years prediction of 0.83. Thereby, the Kattan nomogram showed a significant higher predictive accuracy (p=0.0274). For that reason preoperative nomograms derived in the U.S. can be applied to german patients. However, we would recommend the utilization of the Kattan nomogram due to its higher predictive accuracy.

Biomarkers, Tumor↗
PubMed2003

A multiplex PCR assay for the simultaneous detection and discrimination of the seven Eimeria species that infect domestic fowl.

This study reports the development of a novel multiplex PCR assay based on SCAR (Sequence-Characterised Amplified Region) markers for the simultaneous diagnosis of the 7 Eimeria species that infect domestic fowl. Primer pairs specific for each species were designed in order to generate a ladder of amplification products ranging from 200 to 811 bp. Sensitivity tests for each species were carried out, showing a detection threshold of 1-5 pg, which corresponds approximately to 2-8 sporulated oocysts. Distinct isolates of the 7 Eimeria species from different geographical sources were tested and successfully detected by the assay. All the species were amplified homogeneously, whether or not one of them was present in a high quantity, indicating that there was no cross-interference. The assay was also tested with different sources of Taq DNA polymerase and thermocycler models, confirming the high reproducibility of the reaction. The economy of consumables and labour represented by a single-tube reaction greatly facilitates the molecular diagnosis of a large number of samples, making it appropriate for field epizootiological surveys. We propose the use of this multiplex PCR assay as a rapid and cost-effective diagnostic method for the detection and discrimination of the 7 Eimeria species that infect domestic fowl.

Animals↗
PubMed2003

Relative quantification of HLA-DRA1 and -DQA1 expression by real-time reverse transcriptase-polymerase chain reaction (RT-PCR).

Polymorphism in the upstream regulatory region (URR) of the MHC class II DQA1 gene defines 10 different alleles named QAP (DQA1 promoter). In vitro studies have suggested that allelic polymorphism in the HLA-DQA promoter region may result in differences in HLA-DQA1 gene expression. In the present study, we used real-time reverse transcriptase-polymerase chain reaction (RT-PCR) to quantify differences in HLA-DQA1 gene expression. After the isolation of total mRNA, reverse transcription into cDNA was carried out using random hexamer priming and moloney murine leukaemia virus (MMLV) reverse transcriptase. Quantification of DQA1 mRNA species using a set of six group-specific primer pairs for the detection of HLA-DQA1*01, *02, *03, *04, *05 and *06 was carried out on an ABI PRISM GeneAmp 7700 Sequence Detection System (Perkin Elmer, Foster City, CA) with real-time detection and quantification taking advantage of the fluorescence TaqMan technology (Perkin Elmer, Foster City, CA). Normalization of cDNA templates was achieved by glyceraldehyde-3-phosphate dehydrogenase (GAPDH) quantification. In addition, the total amount of mRNA produced by HLA-DQA1 and HLA-DRA1 expression was quantified for comparison. Subsequently, this approach was validated using Raji and HUT-78 cell lines and tested with peripheral mononuclear cells (PBMC) of 45 samples taken from healthy volunteers. The sensitivity was determined with > or = 10(2) copies. Comparison of the allele-specific DQA1 expression with the total expression of DQA1 and DRA1 mRNA indicated that DQA1*04 expression was increased compared with the expression of other alleles of the DQA1 gene. Thus, allele-specific quantification of DQA1 gene products could be achieved by real-time RT-PCR suitable for the analysis of differential expression of DQA1 mRNAs in homozygote and heterozygote combinations.

HLA-DQ Antigens↗
PubMed2003

Do cognitive patterns of brain magnetic activity correlate with hippocampal atrophy in Alzheimer's disease?

BACKGROUND: Many reports support the clinical validity of volumetric MRI measurements in Alzheimer's disease. OBJECTIVE: To integrate functional brain imaging data derived from magnetoencephalography (MEG) and volumetric data in patients with Alzheimer's disease and in age matched controls. METHODS: MEG data were obtained in the context of a probe-letter memory task. Volumetric measurements were obtained for lateral and mesial temporal lobe regions. RESULTS: As expected, Alzheimer's disease patients showed greater hippocampal atrophy than controls bilaterally. MEG derived indices of the degree of activation in left parietal and temporal lobe areas, occurring after 400 ms from stimulus onset, correlated significantly with the relative volume of lateral and mesial temporal regions. In addition, the size of the right hippocampus accounted for a significant portion of the variance in cognitive scores independently of brain activity measures. CONCLUSIONS: These data support the view that there is a relation between hippocampal atrophy and the degree of neurophysiological activity in the left temporal lobe.

Aged↗
PubMed2002

A survey of the inter- and intraspecific RAPD markers of Eimeria spp. of the domestic fowl and the development of reliable diagnostic tools.

Coccidiosis of domestic fowl is a protozoan disease, caused by seven distinct species of the genus Eimeria, which is responsible for important economic losses in poultry production. In order to select RAPD primers for the discrimination of these seven Eimeria species, we carried out an initial screening using samples of E. acervulina, E. tenella and E. maxima. Out of 150 primers tested, 110 generated band profiles specific for each one of these species. A subset of 14 oligonucleotides were also tested for the simultaneous differentiation of the seven species, resulting in 11 discriminative primers. The intraspecific discrimination was assessed for five different species, using samples from different geographic regions including three continents. Numerous primers exhibited highly discriminative band profiles containing strain-specific markers, with a higher variability being observed among strains of E. acervulina than among E. tenella and E. maximastrains. However, no major differences were observed in the band patterns from strains collected in locations near to one another compared to strains originating from distantly located regions. Because RAPD is a technique performed under low stringency conditions, it suffers from poor reproducibility. Aiming at obtaining more reliable markers that might be universally used, we started an effort to convert species-specific RAPD fragments into SCAR markers. An initial conversion of 25 RAPD markers into SCARs, followed by validation of their specificity, resulted in 14 totally new Eimeria species-specific markers that can be used for the molecular diagnosis of the seven species that infect domestic fowl. This work represents a first step in the development of a set of species-specific SCARs that will be useful as tools for molecular diagnosis, genome mapping, and genetic diversity studies.

Animals↗
PubMed2001

Bone marrow-derived macrophages express functional CGRP receptors and respond to CGRP by increasing transcription of c-fos and IL-6 mRNA.

Calcitonin gene-related peptide (CGRP) is a sensory neuropeptide with inflammatory and immunoregulatory properties. CGRP inhibits IL-7 responses by B cell precursors by direct and indirect mechanisms. We recently found that CGRP induces IL-6 and TNF-alpha in long-term bone marrow cultures and that IL-6 and TNF-alpha also inhibit IL-7 responses. Because these are heterogeneous cultures, it was not clear which cells produced IL-6 and TNF-alpha. To determine whether bone marrow-derived macrophages (BMDM) were the source, we did studies to determine whether BMDMs express mRNAs for CGRP receptors and whether CGRP induces c-fos, IL-6, and TNF-alpha mRNA. We found that BMDMs express mRNAs for CRLR and RAMP1, the minimal components for CGRP receptors. CGRP also stimulated dose- and time-dependent increases in c-fos and IL-6. In contrast, CGRP did not induce TNF-alpha in BMDMs. These results suggest that BMDMs are a source of CGRP-induced IL-6 in bone marrow.

Animals↗
PubMed2001

The effect of mode of exposure to Beauveria bassiana on conidia acquisition and host mortality of Colorado potato beetle, Leptinotarsa decemlineata.

The effects of the mode of exposure of second instar Colorado potato beetles to Beauveria bassiana on conidia acquisition and resulting mortality were investigated in laboratory studies. Larvae sprayed directly with a B. bassiana condial suspension, larvae exposed to B. bassiana-treated foliage, and larvae both sprayed and exposed to treated foliage experienced 76, 34, and 77% mortality, respectively. The total number of conidia and the proportion of germinating conidia were measured over time for four sections of the insect body: the ventral surface of the head (consisting mostly of ventral mouth parts), the ventral abdominal surface, the dorsal abdominal surface, and the legs. From observations at 24 and 36 h posttreatment, mean totals of 161.1 conidia per insect were found on sprayed larvae, 256.1 conidia on larvae exposed only to treated foliage, and 408.3 conidia on larvae both sprayed and exposed to treated foliage. On sprayed larvae, the majority of conidia were found on the dorsal abdominal surface, whereas conidia were predominantly found in the ventral abdominal surface and mouth parts on larvae exposed to treated foliage. Between 24 and 36 h postinoculation the percentage of conidia germinating on sprayed larvae increased slightly from 80 to 84%). On the treated foliage, the percentage of germinated conidia on larvae increased from 35% at 24 h to 50% at 36 h posttreatment. Conidia germination on sprayed larvae on treated foliage was 65% at 24 h and 75% at 36 h posttreatment. It is likely that the gradual acquisition of conidia derived from the continuous exposure to B. bassiana inoculum on the foliar surface was responsible for the increase in germination over time on larvae exposed to treated foliage. The density and germination of conidia were observed 0, 4, 8, 12, 16, 20, and 24 h after being sprayed with or dipped in conidia suspensions or exposing insects to contaminated foliage. Conidia germinated twice as fast on sprayed insects as with any other treatment within the first 12 h. This faster germination may be due to the pressure of the sprayer enhancing conidial lodging on cuticular surfaces.

Animals↗
PubMed2001

[Nerve-sparing radical retropubic prostatectomy. Results of a patient survey].

Improved selection criteria have led to an increasing number of nerve-sparing radical retropubic prostatectomies (RRP) in patients with clinically localized prostate cancer. The results based on patient questionnaires regarding postoperative erectile function are described. Between January 1992 and March 1999, 366 patients (mean age: 62.5 years) underwent uni- or bilateral nerve-sparing RRP at our institution. For evaluation of postoperative patient-reported rates of sexual and erectile function, a questionnaire was used after a follow-up of at least 12 months. Data of five operation periods were analyzed. The results of the unilateral procedure for the five operation periods revealed consistent rates of 13-29% for erections sufficient for intercourse. Bilateral nerve-sparing procedures were almost exclusively performed in periods 3 to 5; only four patients from period 2 underwent the bilateral procedure. The rates of intercourse-sufficient erections were 25% (period 2), 61% (period 3), 50% (period 4), and 52% (period 5), respectively. The results of the unilateral procedure were disappointing. However, the bilateral nerve-sparing method achieved much better results inasmuch as about 50% of the patients reported recovery of erections sufficient for sexual intercourse.

Aged↗
PubMed2001

Comprehensive analysis of a large genomic sequence at the putative B-cell chronic lymphocytic leukaemia (B-CLL) tumour suppresser gene locus.

In many haematological diseases, and more particularly in B-cell chronic lymphocytic leukaemia (B-CLL), the existence of a tumour suppressor gene located within the frequently deleted region 13q14.3, has been put forward. A wide candidate region spanning from marker D13S273 to D13S25 has been proposed and an extensive physical map has been constructed by several teams. In this study, we sequenced a minimal core deleted region that we have previously defined and annotated it with flanking available public sequences. Our analysis shows that this region is gene-poor. Furthermore, our work allowed us to identify new alternative transcripts, spanning core regions, of the previously defined candidate genes DLEU1 and DLEU2. Since their putative involvement in B-CLL was controversial, our present study provide support for reconsidering the DLEU1 and DLEU2 genes as B-CLL candidate genes, with a new definition of their organisation and context.

Alternative Splicing↗
PubMed2001

Validation of a telephone-administered geriatric depression scale in a hispanic elderly population.

OBJECTIVE: To develop and validate a Spanish version of the Geriatric Depression Scale (GDS) for telephone administration. DESIGN, SETTING, AND PATIENTS: The original version of the GDS was translated into Spanish. A random sample of 282 ambulatory elderly individuals was contacted by phone. Those completing the phone GDS (GDS-T) were asked to schedule an appointment within two weeks in which we collected data on demographics, physical exam, functional and mental status, and a face-to-face version of the GDS (GDS-P). We estimated question-to-question kappa statistics and the Pearson correlation coefficient between the GDS-T and GDS-P scores. We evaluated reliability of the GDS-T and GDS-P using the Cronbach's alpha coefficient. We estimated the sensitivity, specificity, and criterion validity of the GDS using the DSM IV criteria for depression as our gold standard. RESULTS: Thirty patients (11%) refused to participate. Of the remaining 252 patients, 169 (67%) attended the personal interview. The Cronbach's alpha coefficient was 0.85 for GSD-P and 0.88 for GDS-T. Sensitivity and specificity were 88% and 82% for GDS-P and 84% and 79% for GDS-T. The prevalence of depression in the group completing both scales was 12.8% using the GDS-P and 14.9% using the GDS-T (P >.05). Among those who only completed the GDS-T, the prevalence was 22.7% (P <.05) suggesting that depressed patients kept their appointments less frequently. CONCLUSIONS: The telephone GDS had high internal consistency and was highly correlated with the validated personal administration of the scale, suggesting that it could be a valid instrument for screening of depression among elderly ambulatory Spanish-speaking patients. Because the depression rate was significantly higher among those not presenting to the personal evaluation, the adoption of GDS-T may help detect and plan early interventions in patients who otherwise would not be identified.

Aged↗
PubMed2001

Early postmolt performance of laying hens fed a low-protein corn molt diet supplemented with spent hen meal.

We used a total of 504 commercial Single Comb White Leghorn hens (69 and 65 wk of age) in each of two experiments, and hens were induced to molt by feed withdrawal only. Feed withdrawal lasted for 12 and 11 d, and hens lost 26 and 25%, body weight in Experiments 1 and 2, respectively. All hens were then weighed, and seven replicate groups of 12 hens each were assigned to molt diet treatments. In Experiment 1, diets consisted of a corn basal diet (7.9% CP) or corn basal diet supplemented with 7.5 or 10% spent hen meal (SHM) each from two different sources. In Experiment 2, the corn basal diet or this diet supplemented with 5 or 10% SHM alone or 5% SHM plus Met, Lys, and Trp was evaluated. A molt diet of 16% CP corn-soybean meal was used as a positive control in both experiments. Molt diets were fed for 15 d in both experiments, at which time all hens were fed a 16% CP layer diet. Performance was measured for 8 wk following the beginning of feeding the layer diet. Feeding the low-protein corn molt diet supplemented with 5 to 10% SHM improved early postmolt egg production performance and body weight gain compared with hens fed the corn basal diet alone. The 7.5 and 10% SHM diets yielded early postmolt performance that was not significantly different (P > 0.05) from that of hens fed the high-protein (16% CP) diet. Supplementing the 5% SHM diet with amino acids generally did not significantly improve performance. The present study thus indicates that improved early postmolt performance may be achieved by supplementation of a low-protein corn molt diet with 5 to 10% SHM.

Animal Feed↗
PubMed2001

A validated strategy for side specific prediction of organ confined prostate cancer: a tool to select for nerve sparing radical prostatectomy.

PURPOSE: Nerve sparing radical prostatectomy for prostate cancer should be restricted to patients who harbor tumors without capsular penetration. To our knowledge the selection criteria for nerve sparing radical prostatectomy are not clearly defined. We investigated a panel of preoperative tumor characteristics with respect to their ability to predict organ confined tumor growth for each lobe of the prostate to indicate unilateral or bilateral nerve sparing radical prostatectomy. MATERIALS AND METHODS: Nine preoperative tumor characteristics in 278 patients with clinically localized prostate cancer were included in retrospective univariate and multivariate tree structured regression analysis. The association of clinical stage, serum prostate specific antigen (PSA), PSA density, and results of transrectal ultrasound and systematic sextant biopsy, including a quantitative assessment of cancer in the biopsies with organ confined tumor growth, was statistically evaluated. Except for serum PSA and PSA density preoperative characteristics were considered separately for each prostate lobe. Multivariate analysis results were validated prospectively in 353 patients. RESULTS: On univariate analysis the number of positive biopsies was the most useful single parameter with a positive predictive value of 83% in 274 lobes and a negative predictive value of 55%, followed by mm. of tumor in the biopsy. Of all characteristics included in multivariate analysis only the number of biopsies with high grade cancer, the number of positive biopsies and serum PSA were independent for predicting organ confined cancer. When PSA was less than 10 ng./ml. and not more than 1 biopsy with high grade cancer was identified in a lobe, organ confined tumor growth was present in 86.1% of cases. On prospective validation the same criteria led to an 88.5% incidence of organ confined prostate cancer. Pooling the 2 most favorable groups led to 391 prostate lobes (70.8% of those investigated) with a positive predictive value of 82.1% (95% confidence interval 77.9% to 85.8%). Using the multivariate approach more prostate lobes were assigned to a favorable risk group than on univariate analysis. Clinical stage and simple Gleason grade did not contribute independent information for predicting organ confined disease. CONCLUSIONS: Quantifying cancer and high grade cancer by systematic biopsy and serum PSA concentration are useful preoperative characteristics for predicting organ confined prostate cancer. Side specific analysis of these parameters is a flexible and reliable tool for selecting patients for nerve sparing radical prostatectomy.

Humans↗
PubMed2000

Lack of agreement between tonometric and gastric juice partial carbon dioxide tension.

STATEMENT OF FINDINGS: Our goal was to compare measurement of tonometered saline and gastric juice partial carbon dioxide tension (PCO2). In this prospective observational study, 112 pairs of measurements were simultaneously obtained under various hemodynamic conditions, in 15 critical care patients. Linear regression analysis showed a significant correlation between the two methods of measuring PCO2 (r(2) = 0.43; P < 0.0001). However, gastric juice PCO2 was systematically higher (mean difference 51 mmHg). The 95% limits of agreement were 315 mmHg and the dispersion increased as the values of PCO2 increased. Tonometric and gastric juice PCO2 cannot be used interchangeably. Gastric juice PCO2 measurement should be interpreted with caution.

Adolescent↗
PubMed2000

The rostro-caudal position of cardiac myocytes affect their fate.

During chick embryogenesis, cells destined to form cardiac myocytes are located within the primitive streak at stage 3 in the same relative anterior-posterior distribution as in the prelooped heart. The most rostral cells contribute to the extreme anterior pole of the heart, the bulbus cordis, and the most caudal to the extreme posterior end, the sinoatrial region. After gastrulation, these cells commit to the myocyte lineage and, retaining their relative positions, migrate to the anterior lateral plate. From stages 5 to 10 they diversify into atrial and ventricular myocytes, with the former located posteriorly and the latter, anteriorly. To determine the effect of a change in the rostro-caudal position of these cells on their diversification, anterior lateral plate mesoderm and the underlying endoderm were cut and rotated 180 degrees along the longitudinal axis, at stages 4-8. The subsequent diversification of these precursor cells into atrial and ventricular myocytes was examined using lineage-specific markers. Our results showed that altering location along the longitudinal axis through stage 6 changed the normal fate of a precursor cell. The orientation of the overlying ectoderm did not alter normal morphogenesis or determination of fate.

Animals↗
PubMed2000

Calcitonin-gene related peptide (CGRP) inhibits interleukin-7-induced pre-B cell colony formation.

Calcitonin gene-related peptide (CGRP) is a sensory neuropeptide with inflammatory and immunoregulatory activities. Its role in B lymphocyte development was investigated using a pre-B cell colony-forming assay. Physiological concentrations of CGRP inhibited pre-B cell responses to interleukin-7 (IL-7). Inhibition was specific in that it was blocked by the CGRP antagonist CGRP8-37. Adrenomedulin, substance P, and calcitonin had no effect on B cell precursor responses. Similar responses were observed with B220+/IgM- B cell precursors. Inhibition of IL-7 responses in B220+/IgM- cells suggests that CGRP has a direct effect on B cell precursors. Studies with cultured bone marrow-adherent cells found that CGRP also has an indirect effect on IL-7 responses. Cultured bone marrow-adherent cells were treated with CGRP for 24 h, and anti-CGRP was added to the supernatants to neutralize CGRP. Concentrations of CGRP as low as 0.01 nM induced a factor that inhibited colony formation. In contrast, CGRP did not induce an inhibitory factor in cultured bone marrow macrophages, suggesting that CGRP induces an inhibitory factor in some adherent cell other than macrophages. The results show that CGRP has both direct and indirect effects on developing B cells and support a role for CGRP as an inhibitor of early B cell development.

Adrenomedullin↗