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Biomedical subjects

N Pérez

Publications and source records attributed to N Pérez.

At least 19 recordsLinked to original sources
PubMed2006

Two-factor design for coagulant/flocculant doses effect for solid-liquid separation of dairy manure.

Screened dairy manure, with a total solids content equal to 34.7 g TS l(-1), was subjected to a coagulation-flocculation treatment using FeCl, as coagulant and a medium cationic polyacrylamide (MCP1). The effect of changing doses of the additives (FeCl3 and MCP1) on the properties of supernatant fractions was studied by means of design of response surface using "Statgraphics Plus 3.0" program. The results showed that the values of concentrations found in supernatants obtained after settling of the flocs for two of the dependent variables studied, filtrate chemical oxygen demand (CODf) and total organic carbon (TOC), were significantly influenced by both the FeCl3 and MCP1 doses at an error lower than 5%. The values of concentrations of the remaining variables studied (TS, VS, CODt, CODvfa) were significantly influenced only by the MCP1 dose at an error lower than 5%. The predictive model obtained the best satisfactory parameters for TOC supernatant's concentration (R2=0.980, F-ratio = 438.89 (p-value < 0.05)) and the worse for VS (R2 = 0.783, F-ratio = 33.43 (p-value < 0.05)).

Acrylic Resins↗
PubMed2006

Fibrous Histiocytoma-like Spindle-Cell Proliferation in the Nipple After Body-Piercing.

We report the case of a 19-year-old pregnant woman who presented with a nipple tumor. The lesion consisted in a spindle-cell proliferation with histologic features similar to those of fibrous histiocytoma, with a highly vascularized stroma. Although it showed low mitotic activity, scattered marked atypical cells with prominent nucleoli were identified, thus raising concern about the benign nature of the tumor. Immunohistochemical evaluation revealed that the spindle cells were diffusely positive for vimentin, focally positive for CD68, and negative for all the other tested antibodies. The patient had a total excision of the lesion and she is free of disease after 30 months. To our knowledge this is the first reported case of a lesion of this type in the nipple after body-piercing.

Adult↗
PubMed2005

[Postural analysis of the test "timed-up-and-go" in patients with vertigo].

INTRODUCTION AND OBJECTIVES: To characterize and analyze the "Timed-up-and-go" test in non-fallers patients with peripheral vertigo. To assess if turning to the side of the lesion induces a more intense instability. MATERIAL AND METHODS: The test was performed after carefully explanation to the patient who was allowed to do some attempts. Postural measurements were the angle and angular speed of trunk sway in roll and pitch. It was done with a special device adapted to the trunk with two sensors specially built for that purpose. CONCLUSIONS: Dizzy, non-fallers patients perform this test in a period of time considered as normal. Canal paresis influences in roll trunk sway when the patient performs the TUG only when turning to the normal side.

Adult↗
PubMed2004

Native valve endocarditis due to Candida glabrata treated without valvular replacement: a potential role for caspofungin in the induction and maintenance treatment.

Conventional antifungal therapy for fungal endocarditis has been associated with a poor cure rate. Therefore, combined medical and surgical therapy has been recommended. However, new potent antifungal agents, such as echinocandins, could increase the medical options and, in some cases, avoid the need for surgery. We report a case of Candida endocarditis treated successfully without valve replacement with intravenous liposomal amphotericin B (total dose, 4 g) and intravenous caspofungin (a 100-mg loading dose followed by 50 mg per day for 8 weeks) as induction therapy and intravenous caspofungin (100 mg 3 times per week for 12 weeks) as maintenance therapy.

Aged, 80 and over↗
PubMed2004

Activity of aphids associated with lettuce and broccoli in Spain and their efficiency as vectors of Lettuce mosaic virus.

This research sought to identify the aphid virus vector species associated with lettuce and broccoli crops in Spain, and to determine their population dynamics and ability to transmit Lettuce mosaic virus (LMV). Green tile traps and Moericke yellow water-pan traps were used to monitor aphid flights during the spring and autumn growing seasons of 2001. Aphid species feeding on lettuce were counted weekly. The transmission efficiencies of LMV were determined for the aphid species caught most frequently. The Moericke traps generally caught more aphid species than the tile trap, but the latter was the most suitable to estimate flight activity of species involved in virus spread. Spring aphid catches indicated that the main aphid species landing on lettuce in the regions of Madrid and Murcia was Hyperomyzus lactucae, but Brachycaudus helichrysi was also abundant in both regions. In broccoli in the Navarra region, the most abundant species in spring were Aphis fabae, B. helichrysi and H. lactucae. In autumn-sown crops, the main species landing on lettuce in the Madrid region were Hyadaphis coriandri and Aphis spiraecola. In Murcia, A. spiraecola and Myzus persicae were the most abundant, while in Navarra, Therioaphis trifolii, and various Aphis spp. were the most numerous landing on broccoli. The main aphid species colonising lettuce was Nasonovia ribisnigri, but other less abundant colonising species were Aulacorthum solani and Macrosiphum euphorbiae. The most efficient vectors of LMV were M. persicae, Aphis gossypii and M. euphorbiae, while A. fabae and H. lactucae transmitted with low efficiency, and Rhopalosiphum padi and N. ribisnigri did not transmit. Occurrence of LMV epidemics in central Spain in relation to aphid flights and the role of weeds as virus reservoirs is discussed.

Animals↗
PubMed2003

The births of five Spanish babies from cryopreserved donated oocytes.

BACKGROUND: The technique of freezing oocytes is still not widely used. Reasons cited for this include the technique's low efficacy and the risk of aneuploidy. However, the introduction of technical changes (the type and concentration of cryoprotective substances; slow freezing and rapid thawing; and fertilization by ICSI) has led to improved results. We present four pregnancies obtained using mature oocytes (in metaphase II) that had been frozen and thawed. The oocytes were donated by young women who were not patients. METHODS: The frozen oocytes (n = 88) came from seven donors aged 18-25 years. The metaphase II oocytes, morphologically normal in appearance, were denuded of their cumulus-corona complex. The cryoprotective freezing solution contained 1,2-propanediol (1.5 mol/l) and sucrose (0.3 mol/l). Freezing was slow and thawing rapid. The oocytes were fertilized by ICSI. RESULTS: Seventy-nine of the 88 thawed oocytes survived (89.8%); 58 were fertilized (73.4% of all those microinjected); and 26 were transferred (44.8% of all those fertilized). Four pregnancies were produced after seven transfers (57.1%). Five children were born from four pregnancies. CONCLUSIONS: With the freezing/thawing technique used, oocyte survival was high ( approximately 90%). The pregnancy rate with frozen oocytes was similar to that obtained using fresh oocytes from donors ( approximately 50%).

Adult↗
PubMed2003

Primary meningococcal conjunctivitis.

Neisseria meningitidis is an uncommon cause of acute bacterial conjunctivitis. One case of primary meningococcal conjunctivitis in a healthy 6-year-old boy is reported. The patient was initially treated with a topical instillation of polymyxin B, neomycin and gramicidin in ophthalmic solution, and this was followed by systemic rifampin once the diagnosis had been established. No ocular or systemic complications developed.

Administration, Oral↗
PubMed2001

Duodenal switch: an effective therapy for morbid obesity--intermediate results.

BACKGROUND: The duodenal switch (DS) is a variant of the biliopancreatic diversion (BPD), with a vertical subtotal gastrectomy and pylorus preservation. METHODS: DS was used to treat morbid obesity in 125 patients, with mean BMI 50, with 65% of the patients super obese (SO). Patients have been followed for an intermediate period. RESULTS: The percentage of excess weight loss (%EWL) was > 70% at 1 year, and reached 81.4% at 5 years when 97% of the patients had a %EWL > 50%. Comorbidities were cured or improved in all patients. CONCLUSION: DS was very effective for the treatment of the morbid obesity in the SO patients.

Adolescent↗
PubMed2000

Preimplantation genetic diagnosis.

Preimplantation genetic diagnosis (PGD) includes a variety of techniques that have been developed to detect the transmission to the offspring of genetic diseases or of chromosome abnormalities by couples at risk before a pregnancy is established, to avoid these couples the risk of recurrent abortions and/or of repeated terminations of pregnancy. Candidate couples are carriers of gene mutations or of structural chromosome rearrangements, or with recurrent spontaneous abortions of unknown origin. Diagnostic procedures include different modalities of gene amplification using the polymerase chain reaction (PCR) or of fluorescent in situ hybridization (FISH). Embryo biopsies are carried out at the 6-8 cell stage. Healthy embryos are transferred on day 4 or at the blastocyst stage. By now, several hundred healthy children have been born using PGD, and only one diagnostic error has been reported.

Abortion, Habitual↗
PubMed2000

Auditory brainstem implantation in primates: lessons for human surgery and application.

We report on the surgical technique for surface electro-auditory prosthesis (EAP) implantation, pathological changes occurring at the cochlear nucleus complex (CNC), and its relation with electrical stimulation. Fourteen Macaca fascicularis were operated upon for a translabyrinthine bilateral auditory neurectomy, and simultaneous unilateral EAP implantation. Six animals were not stimulated, and the remaining eight were connected to an external active device. Stimulation was planned for 1000 hours. Biotolerance to the materials was adequate without significant reactions in the CNC surface, but an ependymal reaction. Lesions attributed to surgical trauma were also found. Two animals being stimulated could not complete the planned course due to cable break or EAP extrusion. One stimulated animal developed an asymptomatic brainstem abscess. A good knowledge of CNC topography is required to avoid surgical trauma. Externally connected devices may facilitate extrusion of the EAP or ascending infections.

Animals↗
PubMed2000

Circulating and mitogen-induced tumor necrosis factor (TNF) in malnourished children.

Malnutrition in children is associated with an increased risk of infection and death. Multiple abnormalities in the inflammatory-immune response, including cytokine production, have been described in protein energy malnourished (PEM) children and could account for increased severity and frequency of infection. The aim of the present study was to determine whether there are abnormal basal tumor necrosis factor (TNF) serum concentrations in PEM children, to relate it with serum cortisol and plasma corticotrophin levels and to explore simultaneously the in vitro production of TNF by peripheral blood leukocytes (PBL). No differences were found in basal plasma corticotrophin and serum cortisol concentrations in malnourished as compared with normal, well-nourished control children. Basal TNF serum concentrations were significantly higher in malnourished children than in controls. Conversely, mitogen induced TNF production by PBL in vitro was significantly reduced in PEM children compared with controls. Abnormalities in circulating and mitogen-induced TNF production are present in malnourished children even in absence of elevated serum cortisol concentrations. These abnormalities potentially could modify inflammatory-immune responses to infectious stimuli in malnourished children.

Adrenocorticotropic Hormone↗
PubMed2000

[Cultural adaptation of 2 questionnaires for health measurement in patients with vertigo].

OBJECTIVE: To perform a transcultural adaptation form English to Spanish of two common questionnaires of handicap assessment in vestibular disorders. STUDY DESIGN: Prospective study. PATIENTS: 337 patients seen for non-acute dizziness from peripheral or central origin in a tertiary referral setting. MAIN OUTCOME MEASURES: Dizziness Handicap Inventory test and UCLA-Dizziness Questionnaire after transcultural adaptation following the method of translation-backtranslation, expert assessment and statistical validation. RESULTS: The results after cultural adaptation and reliability assessment provide a firm basis to demonstrate the close relation of the Spanish and English version in all the items and their meaning. CONCLUSION: This adapted questionnaires can be used to assess vestibular disability with no loss of metric values of the original version.

Adolescent↗
PubMed1999

Andersen syndrome autosomal dominant in three generations.

Andersen syndrome is a rare entity and comprises potassium sensitive periodic paralysis, ventricular arrhythmia, and an unusual facial appearance; syncope and sudden death have also been reported. The recognition of the characteristic face permits an early diagnosis in order to detect the severe systemic manifestations that are associated with this syndrome. The genetic defect is not linked to any other form of potassium sensitive periodic paralysis nor is it related to that of the long QT syndrome; nevertheless, a prolonged QT interval can be detected in a significant proportion of the cases. Sixteen cases of this syndrome have been described. We report on a three-generation family with 10 affected members. To our knowledge, this is the largest number of cases reported in one family. We noted some additional minor anomalies such as broad forehead and malar hypoplasia. Our patients had variable expression in the classical triad and of the severity of the systemic manifestations. Five of 8 affected studied members did not have a long QTc, which has been suggested as a constant finding in this syndrome.

Adolescent↗
PubMed1998

Technetium-99m-labeled anti-EGF-receptor antibody in patients with tumor of epithelial origin: I. Biodistribution and dosimetry for radioimmunotherapy.

UNLABELLED: Accurate estimation of biodistribution and absorbed dose to normal organs and tumors is important for immunoscintigraphic studies and radioimmunotherapy treatment planning. METHODS: Four patients (3 men, 1 woman; mean age 54.8 +/- 9.2 yr; range 42-64 yr) were administered 3 mg of anti-human epidermal growth factor receptor (anti-hEGF-r) antibody (ior egf/r3), radiolabeled with 99mTc activity of 39.5 +/- 1.1 mCi (range 38.5 mCi-40.7 mCi) by intravenous bolus infusion. After administration, blood and urine samples were collected from three patients up to 24 hr after injection. Whole-body anterior and posterior scans were obtained at 5 min and 1, 3, 5 and 24 hr after injection. Using a computer program, regions of interest were drawn over the heart, liver, spleen, bladder and tumor to measure the activity in the source organs at each scanning time. Time-activity curves for each source organ were then fitted to monoexponential or biexponential functions by nonlinear least squares regression using the flexible polyhedrals method, which adequately fit our data with the correlation coefficient of 0.985 +/- 0.013, and were integrated to determine organ residence times. The mean absorbed doses to the whole body and various normal organs were then estimated from residence times and from blood and urine samples using the methods developed by the Medical Internal Radiation Dose Committee. The effective dose equivalent and effective dose were calculated as prescribed in ICRP Publication Nos. 30 and 60. RESULTS: Plasma disappearance curves of 99mTc-labeled anti-hEGF-r antibody were best-fit by a two-compartment model in all patients with a distribution half-life (t(1/2alpha)) of 0.207 hr +/- 0.059 hr (mean +/- s.d., n = 3) and an elimination half-life (t(1/2beta)) of 13.9 hr +/- 2.2 hr. Among the various organs, significant accumulation of the radiolabeled antibody was found in the liver (48.5% +/- 4.4%, mean +/- s.d.), heart (3.50% +/- 0.17%) and spleen (3.1% +/- 1.8%) at 5 min postadministration. These values were reduced to 3.2% +/- 0.4%, 0.1% +/- 0.01% and 0.1% +/- 0.1%, respectively, at 24 hr. Mean cumulative urinary excretion of 99mTc-labeled anti-hEGF-r antibody was 4.6% +/- 0.6% at 24 hr postinjection. Estimates of radiation absorbed dose to normal organs in rad/mCi administered (mean +/- s.d., n = 4) were: whole body 0.017 +/- 0.002; gallbladder wall 0.074 +/- 0.007; spleen 0.136 +/- 0.076; and liver 0.267 +/- 0.036. The effective dose equivalent and effective dose estimates for adults were 0.041 +/- 0.008 rem/mCi and 0.027 +/- 0.004 rem/mCi administered. CONCLUSION: This feasibility study indicates that 99mTc-labeled anti-hEGF-r antibody (ior egf/r3) can be used safely; this analysis provides a dosimetric framework for future studies. This monoclonal antibody, labeled with 188Re, could possibly permit a successful regional radioimmunotherapy of tumors of epithelial origin.

Adult↗
PubMed1998

Single dose study of the bioequivalence of two sustained-release theophylline formulations.

The relative bioavailability of theophylline (CAS 58-55-9) was evaluated after a single dose administration of two sustained-release theophylline tablet formulations: Controfilina-200 as test preparation (test) and a commonly used reference preparation (reference). The design of the study was crossover in twelve healthy volunteers, with a series of two experimental sessions. The two sessions were carried out at weekly intervals. Theophylline concentrations were measured by HPLC (high performance liquid chromatography). The bioavailability was compared using the parameters: AUC0-infinity (area under the concentration-time curve), Cmax (maximal theophylline concentration), tmax (time after drug intake at which the maximal concentration is reached) and Cmax/AUC0-infinity. The results of this study indicated that the new generic sustained-release tablet and the reference are bioequivalent when the same dosage is administered.

Adult↗
PubMed1997

Use of distortion-product otoacoustic emissions for auditory evaluation in Menière's disease.

Otoacoustic emissions are a relatively new tool for assessment of inner ear function. We studied 65 patients diagnosed as having Menière's disease. In order to obtain and characterize responses at different frequencies we used distortion-product otoacoustic emissions (DPOAE). In unilateral cases, the difference in response between ears on the diseased and healthy sides was evident at all frequencies. In the former the result was lower than expected for a group of normally hearing subjects, while in the latter it was better than expected according to pure tone averages. Reduction in amplitude and increment in threshold of the DPOAE in the diseased ear was a significant finding and could be correlated to the stage of the disease. In those subjects treated with Betahistine after 1 year's follow-up, DPOAE testing showed the recovery of response at low frequencies and a reduction of its threshold at all frequencies studied.

Acoustic Stimulation↗