Biomedical subjects

M Quesada

Publications and source records attributed to M Quesada.

At least 19 recordsLinked to original sources

PubMed2006

Inhaled steroids do not decrease bone mineral density but increase risk of fractures: data from the GIUMO Study Group.

Although the negative effect of systemic steroids on bone is well documented, there is not clear evidence about possible adverse effects of inhaled steroids on bone metabolism and fractures. A cross-sectional study was performed on 105 women suffering from bronchial asthma treated with inhaled steroids and 133 controls. Bone mineral density (BMD) was measured by quantitative ultrasonography (QUS) at the calcaneus and by dual X-ray absorptiometry (DXA), at both the lumbar spine and proximal femur. Patients suffering from bronchial asthma showed no statistically significant changes in BMD as measured by DXA or QUS, compared with controls. A higher prevalence of fractures was found in the group of women with bronchial asthma, with an age-adjusted odds ratio of 2.79 (95% CI: 1.19-6.54). Inhaled steroids do not appear to decrease BMD, but are associated with an increased risk of fracture in women.

Absorptiometry, Photon↗

PubMed2006

Prevalence of Rickettsia slovaca in Dermacentor marginatus ticks removed from wild boar (Sus scrofa) in northeastern Spain.

Rickettsia slovaca, the causative agent of TIBOLA, is transmitted by Dermacentor ticks. Dermacentor marginatus is the most widely species distributed in northeastern Spain, and the wild boar constitutes the main host. D. marginatus ticks were collected from hunter-killed wild boar and were tested by PCR/RFLP. Rickettsial DNA-positive ticks were sequenced using the ompA PCR primers. The prevalence of R. slovaca in D. marginatus ticks was 17.7%. Other spotted fever group rickettsiae were detected in ticks, but these were not definitely identified.

Animals↗

PubMed2006

[Helicobacter pylori does not contribute to iron deficiency in hemodialysis patients].

BACKGROUND: Many studies in the general population have shown a link between Helicobacter pylori infection and iron-deficiency, often resulting in iron-deficient anaemia. Despite the high prevalence of iron deficiency in hemodialysis patients, no studies have been performed in this population. OBJECTIVE: To evaluate the role of Helicobacter pylori infection in the appearance of anemia and the iron requirements in our hemodialysis population. MATERIAL AND METHODS: After excluding patients with severe pathology and short life expectancy and those with blood losses secondary to other causes, 79 patients were included.Iron requirements and anaemia were determined by iron serum, ferritin, and hematocrit values; and by transfusion, eritropoietin and iron requirements. The diagnosis of Helicobacter pylori status was established by the concordance of at least two of the three non invasive diagnostic methods performed (breath test, serology and fecal antigen of Helicobacter pylori). RESULTS: Prevalence of Helicobacter pylori infection was 43%. No significant differences between patients infected or not by Helicobacter pylori were found in any of the variables analysed: hematocrit (33.5% versus 34.1%), serum iron (58.9 versus 63.7 pg/dl), ferritin(340.3 versus 264.2 ng/ml), transferrin saturation index (22.5% versus 25.2%), dose of eritropoietin administered (96.6 versus 93.5 U/kg/weekly), and parenteral iron (1,389 versus 1,538 mg/year). A noteworthy finding was that patients with Helicobacter pylori infection had been on hemodialysis for a shorter period than those without (37.4 versus 63.7 months,p = 0.04). CONCLUSION: Helicobacter pylori infection has no effect on anaemia (hematocrit, Eritropoietin dose or iron needs) in our hemodialysis patients. Prevalence of Helicobacter pylori is lower in patients with longer time on dialysis. We consider that the diagnosis of Helicobacter pylori infection must be reserved for clinical peptic ulcer suspicion or patients on transplant waiting list.

Aged↗

PubMed2004

Pneumococcal bacteremia in children: an 8-year review in two hospitals in Barcelona.

In this study, 90 episodes of pneumococcal bacteremia that occurred over an 8-year period in two hospitals in Barcelona were analyzed retrospectively to determine the clinical and bacteriological characteristics of pneumococcal bacteremia, the risk factors for antibiotic resistance, the outcome, and the vaccine coverage. The mean age of the patients was 3.1 years and the male/female ratio was 1.7. The overall rates of penicillin-non-susceptible, cefotaxime-non-susceptible, and erythromycin-resistant isolates were 48.8, 24.4, and 25.5%, respectively. Antibiotic resistance was associated with children under the age of 2 years and with previous antibiotic treatment. The percentage of antibiotic resistance was higher in the nine episodes that occurred in patients with an underlying illness. The most prevalent serotypes identified were 1, 14, 6B, 18C, 5, and 19A. Serotypes 6A/B, 14, and 19A/F were isolated primarily from children under 2, whereas serotypes 1 and 5 were recovered more frequently from older children. Apparent relationships between serotypes 6A/B, 14, and 19A/F and occult bacteremia and between serotypes 1 and 5 and bacteremic pneumonia were confounded by the age variable. The proportion of bacteremic episodes preventable by all (7-valent, 9-valent, and 11-valent) of the conjugate pneumococcal vaccines was 60% in children under 2. In older children, the serotype coverage rate for the three formulations was 48, 87, and 87%, respectively. In summary, these data expand upon previous Spanish studies in which serotypes 1 and 5 were reported to be among the leading causes of severe systemic pneumococcal infections in children over 2, findings that should be taken into consideration when planning vaccine programmes.

Adolescent↗

PubMed2004

Evaluation of three different tests for the detection of stool antigens to diagnose Helicobacter pylori infection in patients with upper gastrointestinal bleeding.

AIM: To evaluate the accuracy of several methods aimed to detect Helicobacter pylori stool antigens in patients with upper gastrointestinal bleeding. METHODS: Thirty-four patients with upper gastrointestinal bleeding because of peptic ulcer were included. The first stool sample during hospitalization was collected, and stool antigens were determined with: polyclonal enzyme-linked immunosorbent assay (Premier-Platinum-HpSA); monoclonal enzyme-linked immunosorbent assay (Amplified-IDEIA-HpStAR); and rapid monoclonal immunochromatographic test (ImmunoCard-STAT HpSA). A patient was considered infected when H. pylori was diagnosed with invasive tests (rapid urease test or histology) or with (13)C-urea breath test. When all tests were negative, a new breath test was repeated after stopping proton pump inhibitors. RESULTS: All patients were infected and, therefore, only sensitivity of the tests could be calculated: polyclonal enzyme-linked immunosorbent assay (74%), monoclonal enzyme-linked immunosorbent assay (94%), and rapid monoclonal immunochromatographic test (60%; concordance between the two observers was high, kappa = 0.9). Neither the presence of maelena nor the delay in obtaining stool samples explained false negatives. CONCLUSIONS: Neither the polyclonal enzyme-linked immunosorbent assay stool antigen test nor the rapid immunochromatographic stool antigen test can be recommended to diagnose H. pylori infection in patients with upper gastrointestinal bleeding. However, the monoclonal enzyme-linked immunosorbent assay stool antigen test is highly sensitive for detecting the infection in patients with this complication, although more studies are necessary to evaluate the specificity of the method.

Antigens, Bacterial↗

PubMed2004

Diagnosis of Helicobacter pylori infection in dyspeptic patients by stool antigen detection usefulness of a new monoclonal enzyme immunoassay test.

BACKGROUND: Helicobacter pylori antigens can be measured in human stools with an enzyme immunoassay, which may prove to be a valuable non-invasive diagnostic tool. Aim. To evaluate the usefulness of a new monoclonal enzyme immunoassay for detecting H. pylori antigens in dyspeptic patients' faeces (FemtoLab H. pylori, Connex, Martinsried, Germany). PATIENTS: H. pylori infection was determined in 75 patients (49 men, 26 women, mean age 52 + 16.5) for histology and rapid urease test. METHODS: H. pylori status was established by concordance of the reference tests. FemtoLab H. pylori was measured in triplicate. In addition, two determinations of a polyclonal faecal antigen test (HpSA, Platinum Premier HpSA, Meridian Diagnostic Inc., Cincinnati, USA) were also performed. Sensitivity, specificity, positive and negative predictive values were calculated. Concordance between different measurements was estimated by Kappa statistics. RESULTS: The sensitivity of the FemtoLab H. pylori immunoassay ranged from 98 to 100% and its specificity was 76%. Positive and negative predictive values were 91 and 94-100%, respectively. Concordance coefficients ranged from 0.81 to 0.92. Corresponding HpSA values were 69, 86, 92 and 53%, respectively. Concordance coefficient was 0.61. CONCLUSIONS: FemtoLab H. pylori is a very sensitive, specific, highly reproducible and easy-to-perform tool for diagnosis of H. pylori infection.

Adolescent↗

PubMed2003

Stool antigen for the diagnosis of Helicobacter pylori infection in cirrhosis: comparative usefulness of three different methods.

BACKGROUND: Helicobacter pylori infection may lead to peptic ulcer disease, and causes significant morbidity in patients with cirrhosis. The measurement of H. pylori antigens in human stools has been proposed as a valuable, non-invasive, diagnostic tool. A number of tests have recently been commercialized. However, very few data are available on their reliability in patients with cirrhosis. AIM: To evaluate the usefulness of three new tests--HpSA (Meridian Diagnostics Inc., Cincinnati, OH, USA), Simple H. pyl (OPERON S.A., Zaragoza, Spain) and FemtoLab H. pylori (Connex, Martinsried, Germany)--in the diagnosis of H. pylori infection in cirrhotic patients. METHODS: H. pylori infection was determined in 79 cirrhotic patients (48 men, 31 women; age range, 29-82 years; mean, 62 +/- 11 years) by concordance of histology and urea breath test. The sensitivity, specificity and positive and negative predictive values of each stool test were calculated. RESULTS: According to the reference method, the sensitivities of HpSA, Simple H. pyl and FemtoLab H. pylori immunoassays were 76%, 87% and 78%, respectively, and their specificities were 93%, 62% and 79%, respectively. CONCLUSIONS: Faecal tests are non-invasive and easy-to-perform tools for the diagnosis of H. pylori infection. However, their sensitivity and specificity seem to be non-optimal in patients with cirrhosis.

Adult↗

PubMed2003

[Evaluation of a rapid test (ImmunoCard STAT! HpSA) for Helicobacter pylori detection in stools].

INTRODUCTION: The use of a rapid diagnostic technique may be extremely useful for the management of Helicobacter pylori infection. A new immunochromatographic in-office test (ImmunoCard STAT! HpSA, Meridian Diagnosis Inc, Cincinnati, Ohio, USA) for the detection of H. pylori in feces has recently become available. The aim of the present study was to evaluate the diagnostic reliability and reproducibility of the ImmunoCard STAT! HpSA test in patients with dyspepsia. PATIENTS AND METHODS: Sixty-three dyspeptic patients were enrolled. H. pylori status was determined by CLO-test and Giemsa staining of antral biopsy. Patients with a positive result for both tests were considered infected and those with a negative result for both tests were considered not infected. Fecal H. pylori antigen was tested twice by ImmunoCard STAT! HpSA. The sensitivity, specificity, positive predictive value and negative predictive value of each determination were calculated. The concordance between the two determinations was evaluated using Kappa statistics. RESULTS: Of the 63 patients, 46 were infected by H. pylori. Sensitivity, specificity and positive and negative predictive values were 89-91%, 86-93%, 96-98% and 72-75%, respectively. The correlation coefficient between determinations was 0.845. CONCLUSION: The new ImmunoCard STAT! HpSA test shows good sensitivity and reproducibility. Therefore, it could be highly useful in the management of H. pylori infection.

Adolescent↗

PubMed2002

Quantitative ultrasound calcaneus measurements: normative data and precision in the spanish population.

Quantitative ultrasound (QUS) assessment at the calcaneus has been found to be a safe and reliable method for evaluating skeletal status. In this study we have determined the normative QUS data in the Spanish population for the Sahara Clinical Sonometer (Hologic). Broadband ultrasound attenuation (BUA), speed of sound (SOS), quantitative ultrasound index (QUI) and estimated bone mineral density (BMD) were determined. We also studied the precision in vivo and in vitro. The short-term in vivo precision (CV) was 4.88% for BUA, 0.36% for SOS, 3.45% for QUI and 4.15% for BMD, while in vitro precision was 0.40% for SOS and 2.67% for BUA. Our results are comparable to reference population data previously published in other countries and may serve as reference normative data for both genders in Spain.

Adolescent↗

PubMed2002

[Smoking cessation and bupropion: anxiety and depression as predictors of therapeutic efficacy].

UNLABELLED: Smoking and depression are related. Bupropion, the first non-nicotinic drug that is an effective treatment in smoking cessation, is a tricyclic antidepressant that inhibits neuronal uptake of serotonin, dopamine and norepinephrine in the thalamic nuclei. OBJECTIVE: To assess if certain personality factors (anxiety or depression) might predict the efficacy of bupropion for smoking cessation. METHOD: The study was carried out in two smoking cessation clinics in Madrid and Barcelona. Fifty patients (21 men) declaring the desire to quit smoking were enrolled. Their mean age was 43.6 years (SD 8.75). The patients were treated with 300 mg of bupropion per day for one month and expired CO was monitored for 6 months. Personality factors were assessed on a hospital anxiety and depression scale (HADS). We evaluated whether there was a significant difference in HADS scores for patients who were still not smoking after 6 months and those who had not managed to quit. RESULTS: The 50 patients were smokers of a mean 39 packs per year (SD 17.82) and had mean scores of 7.4 (SD 4.15) for anxiety and 5.8 (SD 3.93) for depression. Four patients (8%) were unable to complete the study. After one month, 28% of the patients smoked, after 3 months 56% smoked and after 6 months 58% still smoked. The patients who smoked during the first month had higher depression scores than did the non-smokers (p = 0.03). After 3 and 6 months the patients who had managed to continue not smoking were those who had higher anxiety scores than did those who still smoked (p = 0.0052 at 3 months and p = 0.017 at 6 months). CONCLUSION: Patients who responded better to treatment with bupropion after 6 months of follow-up were those with higher anxiety scores on the HADS. Depression levels influenced outcome only during the first month.

Adolescent↗

PubMed1998

Translocation t(1;10) (q21;q26) in a case of acute nonlymphocytic leukemia.

Chromosome banding studies carried out on bone marrow cells from a 16 year-old boy with an M1 acute nonlymphocytic leukemia (ANLL) revealed an unbalanced translocation involving chromosomes 1 and 10: der(10) t(1;10) (q21;q26) that results in a partial trisomy 1q between bands 1q21-1qter. Marker del(6)(q21) and trisomies of chromosomes 18, 21 and 22 were also observed. To our knowledge, this der(10) is the first to be reported in a patient with ANLL.

Adolescent↗

PubMed1998

Modelling the kinetics of antigen-antibody reactions at particle enhanced optical immunoassays.

Functionalized latexes coated by antibodies are used in diagnostic tests for the detection of antigens in biological fluids. A simple kinetic model is presented which is related to the optical monitoring of the formation of specific complexes between antigen and antibody amplified by latex beads. The antibodies are chemically coupled onto chloromethylstyrene (CMST) particles. The kinetic model is able to describe the immunoprecipitin curves of immunolatex beads. The number of fitting parameters is relatively reduced (only three), and the meaning of these parameters can be interpreted in terms of the chemical equilibrium constant, the percentage of active IgG on the latex beads, and optical response. The model explains very well the optical response of immunolatex prepared by covalent coupling of antibodies on polymer carriers.

Animals↗

PubMed1997

Antiresorptive therapy in hyperthyroid patients: longitudinal changes in bone and mineral metabolism.

The effect of antiresorptive therapy with nasal calcitonin (CT) in recently diagnosed hyperthyroid patients on conventional medical therapy as well as the evolution of bone metabolism were assessed. Forty-five patients with recent-onset hyperthyroidism (<12 weeks) were sex and menopause stratified and randomly allocated to treatment with carbimazole (Neotomizol), carbimazole plus low dose CT (Calsynar; 100 IU/day, 2 days/week), or carbimazole plus high dose CT (Calsynar; 100 IU/day, 14 days/month). Bone mineral density was measured by dual x-ray absorptiometry in lumbar spine, femoral neck, and Ward's triangle at 0, 9, and 18 months of treatment. We also determined free T4, free T3, TSH, osteocalcin, total and bone alkaline phosphatases, tartrate-resistant acid phosphatase, type I collagen C telopeptide, and urinary hydroxyproline every 3 months of follow-up. No significant difference was observed among treatments. A euthyroid state was attained at 3 months. Bone mass increased significantly at the 9 month evaluation (P < 0.05), with a 5-10% net gain during follow-up. Nevertheless, final bone mass was 4-8% smaller than expected. Bone formation markers were increased at 0 and 3 months, with reductions at 6-9 months; resorption bone markers showed a significant reduction at the 3 month evaluation. These results indicate that the euthyroid state partially reduces hyperthyroidism-associated osteopenia, with a bone mass recovery period during the 6-9 early months of effective treatment. This recovery phase is characterized by raised bone formation markers and reduced bone resorption markers. The treatment with nasal CT at the doses assayed has no additional effect over that of attainment of the euthyroid state.

Absorptiometry, Photon↗

PubMed1995

Bone mass in androgen-insensitivity syndrome: response to hormonal replacement therapy.

The response of bone mass to long-term treatment with estrogen and progesterone in patients with complete androgen-insensitivity syndrome (AIS) is unknown. We report a 17-year-old female patient (karyotype 46 X, Y) with AIS studied during a 4-year period. Bone mineral density (BMD) measured by dual X-ray absorptiometry in lumbar spine and proximal femur was sharply reduced at the initial visit; and remained unchanged during long-term follow-up on hormone replacement therapy with estrogens and progestin. Bone metabolism markers were all in the normal range. The lack of significant increase in BMD highlights the importance of androgens on bone physiology that cannot be balanced in spite of an appropriate estrogenic milieu.

Absorptiometry, Photon↗

PubMed1994

Changes in serum triiodothyronine kinetics and hepatic type I 5'-deiodinase activity of cold-exposed swine.

Swine exposed to cold air have elevated serum values of total triiodothyronine (TT3) and free T3 (FT3). To characterize the mechanism of these increases, we measured in vivo kinetic parameters after a bolus intravenous injection of 125I-labeled T3 by use of both multicompartmental (MC) and noncompartmental (NC) methods and in vitro hepatic type I iodothyronine 5'-deiodinase (5'D-I) activity. Ten ad libitum-fed 5-mo-old boars were divided into two groups, living for 25 days in either control (22 degrees C) or cold (4 degrees C) conditions. Cold-exposed animals consumed 50% more calories than control animals but showed no difference in total body weight, percent body fat, or plasma volume. Thyroid gland weight was increased 86% (P < 0.004), as was serum total thyroxine (TT4) (48%), free T4 (FT4) (61%), TT3 (103%), and FT3 (107%), whereas serum thyrotropin (TSH) was not different in cold-exposed compared with control animals. The T3 plasma clearance rate was similar between groups when both MC and NC techniques were used. However, T3 plasma appearance rate (PAR) was elevated in cold-treated animals 110% over controls by MC (P < 0.001) and 83% by NC methods (P < 0.001). The animal total hormone pool of T3 was increased 76% (MC) and 53% (NC) compared with control (P < 0.01). The Michaelis constant of hepatic 5'D-I was not different between groups, but the maximum enzyme velocity increased (106%; P < 0.02). Therefore cold exposure for 25 days is associated with increased energy intake, thyroid size, T3 PAR, and hepatic 5'D-I activity with little change in serum TSH.

Acclimatization↗

PubMed1991

[Dermotoglyphics in the Bribri and Cabear Amerindians from Costa Rica].

Digital and palmar dermatoglyphic patterns were analysed for 286 male and female Bribri and Cabecar Amerindians of Chibcha ascendancy from four populations located in southeastern Costa Rica. There was no significant difference among Pacific and Atlantic Cabecar samples, with the exception of the bc and cd ridge count. However, the Bribri groups present differences for 22 features, though the largest differences are between Bribri and Cabecar Pacific populations. A comparison with other Latin-American indians evidence that dermatoglyphic patterns of Bribri and Cabecar tribes are within the expected range, but it is important to notice the high frequency of digital arcs and the low frequency of worls. The results are similar to those observed using other genetic markers in the same populations, and demonstrate the discriminable capacity of the dermatoglyphics to tribal level for taxonomic and evolutionary studies.

Costa Rica↗

PubMed1989

Comparative analysis of photosynthetic light environments within the crowns of juvenile rain forest trees.

Irradiances within the crowns of saplings of two tropical tree species were simultaneously compared in primary rain forest in Costa Rica. The species examined, Minquartia guianensis Aubl., a relatively slow-growing, canopy species, and Pithecellobium pedicellare (DC) Benth., a less-tolerant, emergent species, have different crown and leaf display patterns. Crown light environments were assessed by placing arrays of quantum sensors among leaves and recording at 5-s intervals for seven days with microloggers. Median total daily quantum flux densities for saplings of both species were less than 2% of full sun and did not differ significantly. More than 90% of the measurements within the crowns of these saplings were less than 25 micromol m(-2) s(-1). Spatial variability of photon flux densities within sapling crowns was similar for the two species despite differences in leaf display patterns. In saplings of both species, photon flux densities varied significantly over the relatively short distances within crowns and from day to day. Height growth of both species was significantly correlated with total daily photon flux densities and with percentage of full sun. However, only the tolerant species, Minquartia, showed a significant correlation between diameter growth and crown light environment.

Journal Article↗

PubMed1987

Structure-activity relationships in the 2-arylcarbapenem series: synthesis of 1-methyl-2-arylcarbapenems.

The labile tert-butyldimethylsilyl esters of the azetidinones 6-8b served as the crucial synthons in the preparation of the potentially useful ylide pyridyl thio esters 18-20. These intermediates were utilized to synthesize a host of title carbapenems 25-30d, 32, and 49-53. The antimicrobial properties and DHP-I susceptibility of these carbapenems were studied with reference to thienamycin.

Anti-Bacterial Agents↗