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Biomedical subjects

R Ortiz

Publications and source records attributed to R Ortiz.

At least 37 records · Page 2Linked to original sources
PubMed2001

A pharmacological study of Cecropia obtusifolia Bertol aqueous extract.

Cecropia obtusifolia (Cecropiaceae) is a species from tropical America and its leaves are used in traditional medicine for the treatment of diabetes and as an anti-inflammatory agent. In the present study, the analgesic, anti-inflammatory and central nervous system depressant effects of the aqueous extract from the leaves of C. obtusifolia were investigated in different experimental models, with the purpose of validating its ethnomedical uses. The results obtained with the extract from the leaves of C. obtusifolia reflect a low toxicity, a substantial central depressor effect and analgesic activity and significant motor incoordination and muscle relaxant activity. Concerning the analgesic activity, using the hot plate test, the extract did not produce any effect, however it showed a significant effect on the pain induced by chemical stimuli (acetic and formalin test); this suggests the peripheral analgesic effect of the extract. The extract also showed a topical and systemic anti-inflammatory effect. Thus this work could justify the popular use of C. obtusifolia in rheumatic and kidney inflammation pathologies and reveals that this plant is an interesting species.

Analgesics↗
PubMed2001

CD45RA and CD45RO isoforms in infected malnourished and infected well-nourished children.

The aim of this study was to determine if the distribution in vivo of CD4(+)CD45RA(+)/CD45RO(-) (naive), CD4(+)CD45RA(+)/CD45RO(+) (Ddull) and CD4(+)CD45RO(+) (memory) lymphocytes differs in malnourished infected and well-nourished infected children. The expression of CD45RA (naive) and CD45RO (memory) antigens on CD4(+) lymphocytes was analysed by flow cytometry in a prospectively followed cohort of 15 malnourished infected, 12 well-nourished infected and 10 well-nourished uninfected children. Malnourished infected children showed higher fractions of Ddull cells (11.4 +/- 0.7%) and lower fractions of memory cells (20.3 +/- 1.7%) than the well-nourished infected group (8.8 +/- 0.8 and 28.1 +/- 1.8%, respectively). Well-nourished infected children showed increased percentages of memory cells, an expected response to infection. Impairment of the transition switch to the CD45 isoforms in malnourished children may explain these findings, and may be one of the mechanisms involved in immunodeficiency in these children.

Bacterial Infections↗
PubMed2001

Ring 20 chromosome syndrome with epilepsy and dysmorphic features: a case report.

Relatively few cases of the 20 ring chromosome [r(20)] syndrome have been reported. Epileptic seizures, behavioral problems, mental retardation, and absence of definite dysmorphic features characterize this syndrome. We present a patient with the classic genetic and phenotypic findings. A 42-month-old boy with mild dysmorphic features and psychomotor retardation has had generalized tonic-clonic seizures, resistant to antiepileptic drug therapy since he was 26 months old. Electroencephalography (EEG) was performed on several occasions, as were brainstem auditory evoked potentials (BAEPs), magnetic resonance imaging (MRI), and cytogenetic studies. The EEG showed slow waves in anterior regions intermingled with spikes in temporal areas. The BAEPs were abnormal, and neuroimaging studies were normal. The chromosome r(20) appeared in 100 metaphases studied. Parental chromosomes were of normal karyotype. The genetic and EEG finding from this patient strongly suggest that epilepsy associated with 20 ring chromosome syndrome is a distinct new entity, although the clinical manifestations may be broader than previously recognized.

Abnormalities, Multiple↗
PubMed2001

Flow cytometric analysis of spontaneous and dexamethasone-induced apoptosis in thymocytes from severely malnourished rats.

Severe malnutrition is widely distributed throughout the world, showing a high prevalence in developing countries. Experimental animal models have been useful to study the effects of malnutrition at different levels and ages. Apoptosis is a well recognised process of cell death occurring under several physiological and pathological conditions. It represents the principal mechanism involved in cell selection in the thymus. Thymocyte apoptosis induction by dexamethasone is one of the best characterised experimental models of programmed cell death. The aim of the present study was to determine whether severe malnutrition increased spontaneous and/or dexamethasone-induced apoptosis in vivo in thymocytes of experimentally malnourished rats during lactation. Thymocytes were obtained from malnourished rats at weaning (21d of age). Apoptosis frequency was estimated by the terminal transferase-mediated dUTP nick end labelling assay. Spontaneous apoptosis was 1.9 (sd 1.0) % in well nourished rats in contrast to 13.3 (sd 3.8) % in malnourished animals; this is seven times greater (P<0.001). Interestingly, the frequency of dexamethasone-induced apoptosis was similar in both groups of animals (47.9 (sd 10.1) % in well nourished rats and 53.8 (sd 8.0) % in malnourished rats). The results obtained in the present study indicate that malnutrition is associated with a significant increase of spontaneously apoptotic cells. In addition, the data showed that the fraction of thymocytes susceptible to dexamethasone-induced apoptosis was similar in well nourished and malnourished animals. The greater levels of spontaneously apoptotic cells associated with malnutrition could be related to alterations of the microenvironment of the thymus and/or to an obstruction of early thymocyte maturation.

Animals↗
PubMed2001

[Multicenter study on the usefulness of the NasOral system for the denitrogenation and apneic oxygenation in anesthesia].

OBJECTIVES: To study the usefulness of the NasOral system for denitrogenation prior to anesthetic induction for improving pulmonary oxygen storage that maintains SpO2 within the normal range during induced apnea and facilitates apneic oxygenation. MATERIAL AND METHODS: To establish the study population of 125, five hospitals of the Valencian Community (Spain) enrolled patients scheduled for elective procedures under general anesthesia. The patients were preoxygenated using the NasOral system (denitrogenation). For two minutes, the patients inhaled oxygen through the nose (FiO2 1) at a flow rate of 8-10 l/min (never less than the patient's own minute volume) and exhaled orally through a unidirectional valve. We measured time of apnea with SpO2 > or = 96% to assess the usefulness of the device for denitrogenation. We also measured PetCO2 after endotracheal intubation and after maximum time of apnea (< or = 10 minutes) to assess use of the device for apneic oxygenation during laryngoscopy. RESULTS: We found no significant differences with regard to age, sex, ASA or Mallampati classification among patient groups enrolled at the participating hospitals. Cox's regression analysis was used to determine relative risk of SpO2 < 96%. At 10 minutes post-apnea, 88.8% of all patients maintained SpO2 > or = 96%. However, SpO2 > 96% was maintained by 94.1% in the Mallampati I group and by 84.1% in the Mallampati II group. SpO2 fell below the cut-off (< 96%) in 33.3% of obese patients and in 7.5% of non-obese patients. Analysis of the likelihood of SpO2 < 96% associated with the variables of obesity, sex, age, ASA and Mallampati classification was significant only for obesity, for which a risk of 1.95 was calculated relative to non-obesity (95% CI 1.14-3.35). The NasOral system allows performance of direct laryngoscopy for oral tracheal intubation, maintaining oxygen flow through the permeable airway to facilitate apneic oxygenation. CONCLUSIONS: The NasOral system facilitates denitrogenation before induction of anesthesia in all patients with permeable nasal fossae as well as apneic oxygenation during laryngoscopy.

Adolescent↗
PubMed2000

Interactions of metal ions with a 2,4-diaminopyrimidine derivative (trimethoprim). Antibacterial studies.

The interaction of copper (II), zinc(II) and cadmium(II) with Trimethoprim (2,4-diamino-5-(3',4',5'-trimethoxybenzyl) pyrimidine) has been studied. The crystal structures of [Zn(Trim)2Cl2] (2) and [Cd(Trim)Cl2(CH3OH)]n (4) are reported. Compound (2) exhibits a distorted tetrahedral environment around the metal center and crystallizes in the triclinic space group P1 with a=10.2397(6), b=10.4500(6), c=16.3336(16) A, alpha=96.141(8), beta=106.085(5), gamma=96.551(5) degrees and Z=2. In complex (4), the Cd(II) centers are bridged sequentially by two chlorine ions to form infinite chains and present a six-coordinated environment; the compound crystallizes in the monoclinic P2(1)/C space group with a=13.958(5), b=7.532(2), c=18.390(2) A, alpha=90, beta=97.32(5), gamma=90 degrees and Z=4. In both structures the Trimethoprim acts as a monodentate ligand through the pyrimidinic nitrogen N(1) atom. The characterization of the Cu(Trim)2(CH3O)(ClO4) complex through EPR and magnetic measurements suggests a binuclear or polinuclear nature, with bridging methoxo groups. The complexes were screened for their activity against several bacteria, showing activity similar to that of trimethoprim.

Anti-Bacterial Agents↗
PubMed2000

Daily social and physical activity increases slow-wave sleep and daytime neuropsychological performance in the elderly.

Decreased levels of physical and social activity associated with aging can be particularly pronounced in residents of assisted living facilities. Reduced exposure to important behavioral and time-giving cues may contribute to the age-related changes in circadian rhythmicity and sleep. The present study was conducted to test the hypothesis that an enforced schedule of structured social and physical activity (0:900 to 10:30 and 19:00 to 20:30 daily for two weeks) can have beneficial effects on circadian rhythmicity, nocturnal sleep, daytime functioning, mood, and vigor. The subjects were 14 elderly residents of continued-care retirement facilities while a similar group of 9 elderly residents served as controls. The group exposed to structured activities had increased amounts of slow-wave sleep and demonstrated improvement in memory-oriented tasks following the intervention. Conversely, no significant changes were noted in the amplitude and phase of the body temperature rhythm or in subjective measures of vigor and mood. These results indicate that short-term exposure to structured social intervention and light physical activity can significantly improve memory performance and enhance slow-wave sleep in older adults without alterations to the circadian phase or amplitude of body temperature. This is the first report to demonstrate that low intensity activity in an elderly population can increase deep sleep and improve memory functioning. The high degree of interest in these activities paired with the simple nature of the tasks makes this a potentially practical intervention which can be adapted for both community dwelling and assisted-living elders.

Adult↗
PubMed1999

[Radioimmunoscintigraphy of colorectal cancer using the anti-CEA monoclonal antibody BW 431/26. Final results].

The anti-carcinoembryonic antigen (CEA) antibody, BW 431/26 (Scintimun CEA, Behringwerke, Marburg, Germany ) labeled with technetium pertechnectate (99mTc), is an intact immunoglobulin G1, monoclonal antibody that has been used to image colorectal cancer. Planar and SPECT images of chest, abdomen and pelvis were performed at 10 minutes, 4-6 and 18-24 hours after the intravenous antibody injection. 44 patients were studied and the pathological antibody concentration localization by radioimmunoimaging (RI) were correlated with surgical, clinical and other imaging modality findings to validate the RI. The RI was positive in 29 patients and negative in the other 15 patients. The CEA and CA 19.9 were elevated in the serum of some patients with primary tumors or recurrence. The HAMA were determined in all the patients before and after the RI.

Adult↗
PubMed1998

Cinoxacin complexes with divalent metal ions. Spectroscopic characterization. Crystal structure of a new dinuclear Cd(II) complex having two chelate-bridging carboxylate groups. Antibacterial studies.

Several cinoxacin (HCx) complexes with divalent metal ions have been prepared and characterized by spectroscopic techniques. The crystal structure of [Cd2(Cx)4(H2O)2].10H2O has been determined by X-ray diffraction. The complex is triclinic, space group P1 with unit-cell dimensions: a = 10.412(2), b = 11.119(2), c = 13.143(6)A, chi== 76.78(4) degrees, beta = 74.59(3) degrees, gamma = 77.12(3) degrees, V = 1406.0(8) A3. In this complex each cadmium atom is heptacoordinated: the metal environment is formed by two Oketo and two Ocarbox atoms from two different cinoxacinate monoanions, two carboxylate oxygen atoms from a third cinoxacinate ligand and by one water oxygen atom on the seventh position. Two of the cinoxacinate ions act as tridentate chelate and bridging ligands and the other one as a bidentate chelate ligand. In the bridging monoanions the carboxylate group is behaving as a chelate ligand. All the complexes were screened for their activity against several bacteria, showing activity similar to that of cinoxacin. Additionally, the number of bacteria killed after 3 h of incubation with cinoxacin, [Cu(Cx)2].2H2O and [Co(Cx)3]Na.10H2O complexes was determined against E. coli ATCC 25922; the copper compound presents paradoxical effect which has been described and related to the mechanism of action of quinolones.

4-Quinolones↗
PubMed1998

Effect of early referral to an endocrinologist on efficiency and cost of evaluation and development of treatment plan in patients with thyroid nodules.

Radionuclide uptake and scan and sonogram, frequently ordered before referral to an endocrinologist, are expensive and poor predictors of thyroid nodule malignancy. We estimated costs of excessive imaging and other studies by reviewing the records of all patients (n = 70) referred to a single, consulting endocrinologist, for thyroid nodule evaluation in a 2-yr interval and subsequently, presenting only pertinent histories and results of physical examinations, thyroid function tests, and thyroid autoantibodies, to a second, reviewing endocrinologist (RE) who was blinded to diagnosis and management. Concordance in diagnosis and management between consulting endocrinologist and RE was 87.1% and 93.4%, respectively. Accuracy of diagnosis, loss of patient's time (8.7 h, average), and cost of unnecessary testing, defined as tests not required by the RE for diagnosis and management according to published guidelines, were determined. Unnecessary testing included 153 physician's office or diagnostic laboratory visits, 44 sets of thyroid function tests, 32 radionuclide uptake and scan, 39 thyroid sonograms, and 3 computed tomography scans. The total direct cost of unnecessary tests was estimated at $27,290 ($390/patient) in addition to costs of 30 unnecessary physician's office visits. Only 2 of 8 surgical referrals required surgery, whereas 6 other patients required surgery, including 3 with papillary carcinoma. We conclude that early referral to an endocrinologist of patients with suspected thyroid nodules results in significant savings in cost of evaluation, patient's time, and increased diagnostic precision. Six of the 8 patients referred for surgery before endocrine consultation had benign thyroid disease that did not require surgery. Six additional patients were referred to surgery, 3 of whom had papillary thyroid carcinoma. Early referral of patients with suspected thyroid nodules to an endocrinologist results in significant savings in both cost and patient's time as well as increased precision of diagnosis.

Adolescent↗
PubMed1997

Effects of hypophyseal hormones on transcription and RNA export to the cytoplasm.

The effects of hypophyseal hormones on RNA transcription and export to the cytoplasm were evaluated by means of light microscopic quantitative autoradiography. Normal or hypophysectomized rats as well as hypophysectomized animals treated with the follicle-stimulating hormone (FSH), luteinizing hormone (LH), thyroid-stimulating hormone (TSH), or adrenocorticotropic hormone (ACTH), were used and the corresponding target cells (Sertoli cells, Leydig cells, epithelial thyroid gland cells, or adrenal cortical cells, respectively) were analyzed. Moreover, the variations of the concentration of perichromatin granules were correlated with the changes of the nuclear and cytoplasmic RNA labeling. Hypophysectomy causes a decrease of nuclear and cytoplasmic labeling and a large increase of the number of perichromatin granules in the four cell types studied. The administration of any of the four hormones brings about an increase in the rate of RNA transport to the cytoplasm in the target cells, within short periods (15 to 135 min). This augmentation of the RNA export takes place before any significant increase of the transcription rate, suggesting that the exiting RNA was previously stored in the nucleus. This is in agreement with a decrease of the number of perichromatin granules detected as early as 30 min after the administration of the hormones. Previous work demonstrated that steroid hormones such as estradiol and testosterone have similar effects on their target cells. All these observations indicate that the regulation of the RNA transport to the cytoplasm is an important means of rapid posttranscriptional modulation of the expression of genetic information that can mediate the early action of various regulatory factors.

Adrenal Cortex↗
PubMed1997

Analysis of mitomycin C-induced micronuclei in lymphocytes from malnourished infected children.

The purpose of this study was to determine if peripheral blood lymphocytes from malnourished children with gastrointestinal or respiratory bacterial infection show increased frequencies of Mitomycin C (MMC)-induced micronuclei as compared to well-nourished, infected children. The results indicate that cells from malnourished, infected children had greater chromosome damage. This may indicate that such children would be more susceptible to environmental damage and malignant transformation. Micronucleus frequencies were analyzed in binucleate cells produced by the cytokinesis block method; the overall micronucleus frequency was significantly higher in binucleate cells from malnourished, infected children. The mean micronucleus frequency in MMC-free cultures was 4.3/1000 in malnourished infected children and 1.0/1000 in well-nourished infected children. In MMC-exposed cultures the mean induced micronucleus frequency was 32.6 +/- 6.1 vs. 12.9 +/- 2.3; 68.6 +/- 12.1 vs. 21.0 +/- 5.1, and 88.1 +/- 16.2 vs. 41.7 +/- 5.0 for malnourished and well-nourished children at 20, 40, and 60 ng/ml MMC, respectively. The number of binucleated cells with more than one micronucleus was also higher in malnourished, infected children at all doses tested, including cells with two micronuclei in MMC-free cultures from malnourished, infected children. This increase was not found in peripheral blood lymphocytes from well-nourished infected children.

Antibiotics, Antineoplastic↗
PubMed1997

[Validation of "myocardial infarction" as cause of death on death certificates in Barquisimeto, Lara state, Venezuela]

Death rates due to Ischemic Heart Disease (IHD) are widely used to assess regional and national cardiovascular health status. However, their validity is questionable, essentially because they are based on death certificates (DCs). The present study was conducted in the Greater Metropolitan Area of Barquisimeto (Lara State, Venezuela), from June 1991 to July 1992. The purpose was to establish the validity of the diagnosis of myocardial infarction in DCs of intrahospital deaths. Efforts were made to locate all clinical charts and any other relevant information. To validate the diagnosis of MI in the DC we used the MONICA project criteria. During the study period a total of 247 eligible DCs were recorded. Sufficient clinical information was located for 136 cases (55%). The results were as follows: definite MI - 62 cases (45.6%); probable MI - 31 cases (22.8%); and non MI - 43 cases (31.6%). These results may indicate an overestimation of MI death rates of about 32% [95% Confidence Interval = 23.8% - 39.4%]. Since these data are from a region with an organized cardiovascular health system, it is expected that the overestimation for the rest of the country may be even higher. Thus, in order to enhance quality and accuracy of DCs, it is necessary to develop a system to improve adherence to existing norms for filling out and processing such forms.

Journal Article↗
PubMed1997

Orthostatic sympathetic derangement in subjects with fibromyalgia.

OBJECTIVE: To assess the sympathetic-parasympathetic balance in individuals with fibromyalgia (FM), and its response to orthostatic stress, by power spectral analysis of heart rate variability. METHODS: We studied 19 women with FM and 19 age matched controls. A high resolution electrocardiogram was obtained in supine and standing postures after achieving a stable heart rate. Spectral analysis of R-R intervals was done by the fast Fourier transform algorithm. RESULTS: Analyses of the different frequency components revealed significant difference between the 2 groups in the low frequency (0.050-0.150 Hz) band, which reflects modulation of the sympathetic nervous system. Controls displayed an increased power spectral density upon standing (+0.081 +/- 0.217 Hz); individuals with FM had a discordant response (-0.057 +/- 0.097 Hz) (p = 0.018). CONCLUSION: In FM, there is a deranged sympathetic response to orthostatic stress. This abnormality may have implications regarding the pathogenesis of FM.

Adult↗
PubMed1996

Cell cycle phase duration in bone marrow cells from malnourished rats during suckling.

The generation time and duration of the different phases of the cell cycle were estimated in cultured bone marrow cells from malnourished and well-nourished rats during the lactation period by the percentage labeled mitosis (PLM) technique after a short pulse treatment with tritiated thymidine. The PLM were obtained in sequential analysis after every 3 h from removing labeled thymidine to 27 h of incubation. Results have shown a longer cell cycle time in cells from malnourished rats. The G1 + 1/2M phases are sensitive to experimental severe protein malnutrition (PCM), while S and G2 + 1/2 M phases did not show any differences in duration between malnourished and well-nourished rats.

Animals↗