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Biomedical subjects

E Navarro

Publications and source records attributed to E Navarro.

At least 19 recordsLinked to original sources
PubMed2006

Elenoside increases intestinal motility.

AIM: To study the effects of elenoside, an arylnaph-thalene lignan from Justicia hyssopifolia, on gastro-intestinal motility in vivo and in vitro in rats. METHODS: Routine in vivo experimental assessments were catharsis index, water percentage of boluses, intestinal transit, and codeine antagonism. The groups included were vehicle control (propylene glycol-ethanol-plant oil-tween 80), elenoside (i.p. 25 and 50 mg/kg), cisapride (i.p. 10 mg/kg), and codeine phosphate (intragastric route, 50 mg/kg). In vitro approaches used isolated rat intestinal tissues (duodenum, jejunum, and ileum). The effects of elenoside at concentrations of 3.2 x 10(-4), 6.4 x 10(-4) and 1.2 x 10(-3) mol/L, and cisapride at 10(-6) mol/L were investigated. RESULTS: Elenoside in vivo produced an increase in the catharsis index and water percentage of boluses and in the percentage of distance traveled by a suspension of activated charcoal. Codeine phosphate antagonized the effect of 25 mg/kg of elenoside. In vitro, elenoside in duodenum, jejunum and ileum produced an initial decrease in the contraction force followed by an increase. Elenoside resulted in decreased intestinal frequency in duodenum, jejunum, and ileum. The in vitro and in vivo effects of elenoside were similar to those produced by cisapride. CONCLUSION: Elenoside is a lignan with an action similar to that of purgative and prokinetics drugs. Elenoside, could be an alternative to cisapride in treatment of gastrointestinal diseases as well as a preventive therapy for the undesirable gastrointestinal effects produced by opioids used for mild to moderate pain.

Acanthaceae↗
PubMed2005

Autonomic, endothelial function and the analysis of gait in patients with type 1 and type 2 diabetes.

Ten control subjects and 20 subjects with type 1 and type 2 diabetes were examined to compare autonomic, endothelial function and gait characteristics while walking in a linear path and during turns. To measure deviations in gait, timing was recorded from foot sensors worn in the shoes and from accelerometers (2 axis) mounted on the head, shoulder, hips, knees and ankles, bilaterally. The results of the experiments showed that subjects with diabetes took additional steps when walking in a linear path and during turns. They also took significantly more time to walk a given distance (greater than 30%) than control subjects. Accelerometry data also revealed that there was an increase in flexion/extension and lateral movement at the major joints in the body. Joint movements at the hip, knee, ankle and shoulders showed a 50 and 100% increase in movement at the joints during gait for subjects with diabetes compared to control subjects. These findings suggest that individuals with type 1 and type 2 diabetes can have significant problems in both the timing and quality of gait. These impairments are likely secondary to dysfunction of the vestibular, somatosensory and autonomic system in diabetics. Data here showed at least a 50% impairment in local tissue blood flow and autonomic function in subjects in both type 1 and type 2 diabetes compared to control subjects.

Adult↗
PubMed2005

Effectiveness assessment of otosclerosis surgery.

CONCLUSIONS: The epidemiological characteristics of otosclerosis and its treatment in Andalusia resemble those of other populations with similar socioeconomic levels. Two complementary approaches, such as questionnaires and pure-tone audiometry, are required to assess the effectiveness of otosclerosis surgery (OS) reliably and precisely. OBJECTIVES: We describe a new method to assess effectiveness in OS. It is based on the results of pure-tone audiometry and a specially designed quality of hearing questionnaire (QHQ). The objectives of the study are: (i) to report the general epidemiologic profile of otosclerosis in Andalusia; (ii) to study the effectiveness of OS in our community using conventional methods; and (iii) to study the outcomes of OS using the QHQ and to compare them to those obtained using conventional methods. MATERIAL AND METHODS: All 31 hospitals in the public healthcare system of Andalusia were studied. They were graded into four groups using a specially designed grouping system. The data were obtained from the minimum basic dataset. The prevalence of otosclerosis in Andalusia was calculated from the incidence data, the duration of the disease and life expectancy. To assess the effectiveness of OS, 475 clinical records from 15 hospitals representing all 4 groups were analysed. Effectiveness was assessed by conventional methods, using data obtained from pure-tone audiometry, and by using version 1.02 p of the QHQ. RESULTS: The incidence of clinical otosclerosis was 5.67 patients/100,000 inhabitants/year. The calculated prevalence was 0.287%. The number of cases increased progressively during the study period (p<0.001). The 15-45-year age group was the largest (62.2%) and 68.4% of patients were females. The most frequent type of otosclerosis was estapediovestibularis (fenestral), non-obliterative (91.8%). Only 48 cases (2.3%) of cochlear and 45 (2.2%) of obliterative otosclerosis were reported. The most frequently employed therapeutic procedures were stapedectomy and stapedotomy (75.70%). The average total and preoperative lengths of stay were 3.59 and 1.04 days, respectively. There were significant differences between the different types of otosclerosis. Improvement in the air-bone gap was 15.37+/-1.19 dB (n=164) and the overclosure or operative damage was 0.49+/-0.85 dB (n=164). A gap improvement of 10-40 dB was observed in 61.4% of patients. The > 65 years age group showed the best gap improvement but the largest variability. The quality of hearing measured by the QHQ showed that, in general, a better gap improvement was associated with a higher quality of hearing (Pearson correlation r=0.183; p<0.05). The 15-45-year age group had the worst gap improvement but, in contrast, the better quality of hearing.

Adolescent↗
PubMed2004

Benefits of cognitive-motor intervention in MCI and mild to moderate Alzheimer disease.

OBJECTIVE: To evaluate the efficacy of a cognitive-motor program in patients with early Alzheimer disease (AD) who are treated with a cholinesterase inhibitor (ChEI). METHODS: Patients with mild cognitive impairment (MCI) (12), mild AD (48), and moderate AD (24) (Global Deterioration Scale stages 3, 4, and 5) were randomized to receive psychosocial support plus cognitive-motor intervention (experimental group) or psychosocial support alone (control group). Cognitive-motor intervention (CMI) consisted of a 1-year structured program of 103 sessions of cognitive exercises, plus social and psychomotor activities. The primary efficacy measure was the cognitive subscale of the AD Assessment Scale (ADAS-cog). Secondary efficacy measures were the Mini-Mental State Examination, the Functional Activities Questionnaire, and the Geriatric Depression Scale. Evaluations were conducted at 1, 3, 6, and 12 months by blinded evaluators. RESULTS: Patients in the CMI group maintained cognitive status at month 6, whereas patients in the control group had significantly declined at that time. Cognitive response was higher in the patients with fewer years of formal education. In addition, more patients in the experimental group maintained or improved their affective status at month 12 (experimental group, 75%; control group, 47%; p = 0.017). CONCLUSIONS: A long-term CMI in ChEI-treated early Alzheimer disease patients produced additional mood and cognitive benefits.

Aged↗
PubMed2004

Conformational and structural analysis of the equilibrium between single- and double-strand beta-helix of a D,L-alternating oligonorleucine.

Alternating sequences of D and L residues in peptides are directly related to the formation of several kinds of regular helical conformations usually called beta-helices. The major feature of these structures is that they can be associated with the transmembrane ion-conducting channel activity in some natural antibacterial peptides. The study of alternating D,L synthetic peptides is critical to understand how factors such as surrounding media, main chain length, type of side chain and terminal groups, among others, can determine the adoption of a specific kind of beta-helix. Early studies pointed out that the peptides Boc-(D-NLeu-L-NLeu)(6)-D-MeNLe-L-Nl-D-Nl-L-Nl-OMe (Boc: tert-butyloxycarbonyl) and Boc-L-Nle-(D-Nle-L-Nle)(5)-D-MeNle-L-Nle-D-Nle-L-Nle-OMe adopt in chloroform a unique detectable conformation single beta(4.4)- and double beta(5.6) upward arrow downward arrow -helix, respectively. The influence of terminal groups on the final stable conformation of N-formylated peptides has been studied in this work. The initial basic NMR data analysis of a synthetic alternating D,L-oligopeptide with ten norleucines, N-methylated on the residue 7 and having HCO- and -OMe as terminal groups clearly indicates the coexistence of two different conformations in equilibrium. NMR data and molecular dynamics calculations point to a dimeric antiparallel beta-helix structure beta(5.6) upward arrow downward arrow for the main conformation. On the other hand, NMR data suggest a single beta-helix structure beta(4.4) for the second conformation. Finally, a thermodynamic analysis of the equilibrium between both conformations has been carried out by one-dimensional NMR measurements at ten different temperatures. The temperature at which 50% of dimer conformation is dissociated is 319 K. In addition, the dimer-monomer equilibrium curve obtained shows a DeltaG>0 for the whole range of studied temperatures, and its behavior can be considered similar to the thermodynamic denaturation protein processes.

Amino Acid Sequence↗
PubMed2004

Evaluation of Brucellacapt for the diagnosis of human brucellosis.

OBJECTIVE: To evaluate the role of Brucellacapt in the diagnosis of human brucellosis, and the correlation with the evolution of the disease. METHODS: Twenty-six patients who were admitted to the General Hospital of Albacete (Spain) over a 2-year period and diagnosed with brucellosis were included in the study. One hundred and twenty-three serum samples collected at the time of diagnosis and at intervals during and after treatment were tested by the Coombs test, the standard seroagglutination test (SAT), and Brucellacapt (a new test based on an immunocapture-agglutination technique). To study the specificity of Brucellacapt, sera from 20 patients with other infectious diseases and 20 sera from healthy donors were included in this study. RESULTS: The sensitivity of the Brucellacapt at the moment of diagnosis was similar to the Coombs test (96 and 100%, respectively), somewhat higher than that of SAT (73%). And the specificity of the Brucellacapt (97.5%) was less than SAT and the Coombs test, that was 100%. The correlation between the classical serological tests and Brucellacapt, showed that titers in Brucellacapt and Coombs test of patients were both similar in a range of 1-2 dilutions. The correlation between Brucellacapt and Coombs (r=0.14) and between Brucellacapt and SAT (r=0.0) did not reach statistical significance. However, the correlation coefficient between Coombs and SAT was r=0.8. CONCLUSIONS: Brucellacapt and Coombs tests showed a similar sensitivity and specificity in the diagnosis of human brucellosis. In addition, as Coombs test, Brucellacapt could help to diagnose patients with long evolution of brucellosis that are not detected with SAT.

Adolescent↗
PubMed2004

Central nervous activity of elenoside.

Elenoside is a cytotoxic arylnapthalene lignan (NSC 644013-W/1) derived from Justicia hyssopifolia (Family: Acanthaceae). The neuropharmacological activity of this lignan, a beta-D-glucoside was studied. The LD50 (24 h) of elenoside in mice is 305 +/- 7 mg/kg by i.p. route. In the present study elenoside was given to rats at doses of 25 and 50 mg/kg, and its effects on locomotor activity (Varimex test), muscular relaxant activity, open-field test and with chlorpromazine, 10 mg/kg was compared. On Varimex test, spontaneous activity was reduced. Elenoside produced a reduction in the permanence time on muscular relaxant activity (traction test). On open-field test, ambulation and rearing were reduced compared with the control group and an increase in boluses of dose-dependent rate was obtained. Thus it can be concluded that elenoside has central sedative effects and possible application in anxiety conditions.

Acanthaceae↗
PubMed2003

Clinical utility of a dipstick assay in patients with brucellosis: correlation with the period of evolution of the disease.

To examine the clinical utility of a dipstick assay for the detection of Brucella-specific IgM antibodies, and the correlation with the evolution of the disease. Twenty-six patients who were admitted to the General Hospital of Albacete (Spain) over a 2-year period and diagnosed with brucellosis were included in the study. One hundred and twenty-five serum samples collected at the time of diagnosis and at intervals during and after treatment were tested by the Coombs test, the standard seroagglutination test (SAT), the SAT in the presence of dithiothreitol (DTT-SAT), and a dipstick assay for the detection of Brucella-specific immunoglobulin M (IgM) antibodies. The sensitivity of the dipstick assay at the moment of the diagnosis was similar to that of the SAT (62% and 73%, respectively), somewhat higher than that of the DTT-SAT (50%), and lower than that of the Coombs test (100%). Patients with a negative dipstick test at the moment of diagnosis displayed a period of evolution of the disease longer than that of the dipstick-positive patients. After the beginning of therapy, the detection rate of the dipstick assay decreased faster than those of the SAT, the DTT-SAT, and the Coombs test. Thirty days after the start of therapy, the detection rate of the dipstick assay had decreased to 7%, whereas that of the SAT and DTT-SAT was 46%, and that of the Coombs test was still 92%. The dipstick assay could be used as a rapid diagnostic test for patients in the early stages of illness. Patients with a long period of illness will probably have a negative dipstick test, and could be diagnosed with the aid of the Coombs test and classical clinical findings.

Agglutination Tests↗
PubMed2003

Indoor radon levels in buildings in the Autonomous Community of Extremadura (Spain).

Indoor air samples taken in buildings throughout the provinces of Cáceres and Badajoz in the Autonomous Community of Extremadura, Spain, were analysed for airborne radon concentrations using charcoal canisters. Measurements were made during the years 1998-2000. The geometrical mean indoor concentration was 90 Bq m(-3). An estimated annual effective dose of 1.6 mSv y(-1) was calculated for residents, assuming an equilibrium factor of 0.4 and an occupancy factor of 0.8. The relative importance of the principal variables that condition radon concentrations inside buildings was also delimited experimentally. These were: soil type, construction materials used, the height of the room above ground level, and the degree of ventilation. The temporal evolution of the radon concentration was analysed, as this aspect could be particularly important in a Continental-Mediterranean climate such as that of the two provinces of the study.

Air Pollutants, Radioactive↗
PubMed2002

Comparison of three different PCR methods for detection of Brucella spp in human blood samples.

In the diagnosis of human brucellosis, PCR could be a more sensitive technique than blood cultures and more specific than conventional serological tests. We compared three different PCR methods for the detection of Brucella spp. and we studied whether human genomic DNA affect the sensitivity of three primer pairs for the detection of Brucella DNA in a peripheral-blood PCR assay. These three pairs of primers amplified three different fragments included in: (i). a gene encoding a 31-kDa Brucella abortus antigen (primers B4/B5), (ii). a sequence 16S rRNA of B. abortus (primers F4/R2), and (iii). a gene encoding an outer membrane protein (omp-2) (primers JPF/JPR). The three primers assayed showed a difference in sensitivity for detecting purified Brucella DNA, ranging between 8 fg and 20 pg. However, the sensitivity of the primers F4/R2 and B4/B5 was affected by the presence of human DNA while the primers JPF/JPR were not. Therefore, although the sensitivity of PCR using primers F4/R2 is affected by human DNA, they are still the most sensitive and they could provide a useful tool for the diagnosis of human brucellosis.

Brucella↗
PubMed2002

Solution structure of a D,L-alternating oligonorleucine as a model of double-stranded antiparallel beta-helix.

Conformational characteristics of alternating D,L linear peptides are of particular interest because of their capacity to form transmembrane channels with different transport properties, as some natural antibiotics do. Single- and double-stranded beta-helical structures are common for alternating D,L peptides. The stability of the beta-helix depends on several structural factors, such as the backbone peptide length, type and position of side chains, and nature of terminal groups. The NMR and molecular dynamics solution conformation of a synthetic alternating D,L-oligopeptide with 15 norleucines (XVMe) has been used as a model to get insight in to the conformational features of double-stranded beta-helix structures. The NH chemical shift values (delta(NH)) and long-range nuclear Overhauser effects (NOE) cross peaks, in particular interstrand connectivities, clearly point to an antiparallel double-stranded beta-helix for the XVMe major conformation in solution. An extensive set of distances (from NOE cross peaks) and H-bonds (from delta(NH)) has been included in the molecular dynamics calculations. The experimental NMR data and theoretical calculations clearly indicate that the most probable conformation of XVMe in solution is a double-strand antiparallel beta(5.6) increasing decreasing-helix structure.

Biopolymers↗
PubMed2002

The type, amount, frequency and timing of dietary supplement use by elite players in the First Spanish Basketball League.

The aims of this study were to determine the type, frequency and amount of dietary supplement consumption among a group of professional basketball players. The type, amount and specific timing of supplement use were recorded by 55 professional basketball players from seven different teams of the First Spanish Basketball League. Most participants (58%) consumed dietary supplements. Multivitamins and vitamins were the most frequently used supplements among the athletes (50.9%), followed by sport drinks (21.8%), miscellaneous supplements (21.8%), amino acids (14.5%), proteins (12.7%) and carbohydrates (12.7%). The average daily dietary supplement was one capsule of multivitamins, one capsule of antioxidant vitamins, 0.2-1.0 g vitamin C, 10.3 g protein, 1.9 g amino acids, 16.2 g carbohydrates and 377 ml of a commercial sport drink. Although the proportion of participants who consumed dietary supplements before, during and immediately after exercise was 25.4%, 16.3% and 7.3% respectively, only a few consumed a potentially ergogenic supplement at these times. It would appear unlikely that the type or amount of dietary supplements consumed had a beneficial effect on the physical performance of these professional basketball players, with the possible exception of antioxidant vitamins and the commercial sport drinks.

Adult↗
PubMed2002

[Dominant autosomal cerebral arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). A review].

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a familial condition caused by a mutation of the Notch3 gen in chromosome 19. Accumulation of osmiophilic granular material (GOM) on the middle layer of small and medium-sized cerebral arteries leads to progressive narrowing of the blood vessels. As a result, clinical findings include migraine, cerebrovascular ischemic events, vascular dementia and a number of neuropsychiatric disorders associated to an extensive leukoencephalopathy readily shown by MRI studies. GOM deposits, however, are systemic and maybe shown ultrastructuraly on skin vessels by means of a biopsy. Detection of mutations of the Notch3 gen by molecular genetics may also allow accurate diagnosis during life. So far, there is no effective treatment for this disorder.

Adult↗
PubMed2001

Opposite effects of low and high doses of arginine on glutamate-induced nitric oxide formation in rat substantia nigra.

L-arginine is a very versatile amino acid that is involved in many important physiological processes such as protein, nitric oxide (NO), agmatine, putrescine, urea, L-ornithine or creatine synthesis and is essential for posttranslational arginylation of protein. The present study was designed to evaluate in vivo the effect of L-arginine on NO production in substantia nigra. In vivo spectroscopic and voltammetric studies were addressed in rats to record modifications in methemoglobin and NO levels under glutamate stimulation. Results showed that, under physiological L-arginine extracellular concentration, the intranigral infusion of glutamate produced an increase in NO levels. When a low dose of L-arginine was co-infused with glutamate, a persistent and higher increase in NO levels was observed. The co-infusion of glutamate with a moderate dose of L-arginine induced drastic and persistent NO production. It was also observed that high doses of either L-arginine or D-arginine inhibit NO production. Subsequently, these data show that L-arginine and D-arginine are involved in a mechanism that inhibits NO production.

Animals↗
PubMed2001

Effects of atrazine on periphyton under grazing pressure.

An experiment was carried out using indoor experimental channels to assess the long-term effect (18 days) of herbivores (Physella acuta, Gastropoda) on periphyton communities exposed to low levels of atrazine (14 microg l(-1)). We hypothesized that herbivorism modifies the response of periphyton to atrazine. Carbon incorporation, chlorophyll-a content, biovolume and algal taxonomic composition in the channels that contained atrazine were not significantly different from the control channels (not receiving atrazine). In channels with grazers and atrazine, there was a significant reduction of carbon incorporation and algal density. In this treatment, physiognomic forms and algal composition were significantly different from the others. The biomass of grazers (measured as change in dry mass) was not significantly affected by the addition of atrazine. Grazers maintained low levels of periphyton biomass, enhancing algal cell exposition to toxicant and inhibiting any adaptation of the algae to the toxic exposure. The increase in atrazine toxicity with grazing not only affected the metabolism, but also the structure of the algal community, which suggests that effects were not transient but permanent.

Animals↗
PubMed2001

Solution NMR structure of a D,L-alternating oligonorleucine as a model of beta-helix.

beta-Helix structures are of particular interest due to their capacity to form transmembrane channels with different transport properties. However, the relatively large number of beta-helices configurations does not allow a direct conformational analysis of beta-helical oligopeptides. A synthetic alternating D,L-oligopeptide with twelve norleucines (XIIMe) has been used as a model to get insight in the conformational features of beta-helix structures. The spatial configuration of XIIMe in solution has been determined by NMR. An extensive set of distances (nuclear Overhauser effect) and dihedral (J coupling constants) constraints have been included in molecular dynamics calculations. The NMR experimental data and theoretical calculations clearly indicate that the XIIMe adopts a single beta(4.4)-helix-type conformation in nonpolar solvents.

Models, Molecular↗