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Biomedical subjects

S Blanco

Publications and source records attributed to S Blanco.

At least 19 recordsLinked to original sources
PubMed2003

Maternal and congenital syphilis in Bolivia, 1996: prevalence and risk factors.

OBJECTIVES: The present study was carried out in seven maternity hospitals to determine the prevalence of maternal syphilis at the time of delivery and the associated risk factors, to conduct a pilot project of rapid syphilis testing in hospital laboratories, to assure the quality of syphilis testing, and to determine the rate of congenital syphilis in infants born to women with syphilis at the time of delivery--all of which would provide baseline data for a national prevention programme in Bolivia. METHODS: All women delivering either live-born or stillborn infants in the seven participating hospitals in and around La Paz, El Alto, and Cochabamba between June and November 1996 were eligible for enrolment in the study. FINDINGS: A total of 61 out of 1428 mothers (4.3%) of live-born infants and 11 out of 43 mothers (26%) of stillborn infants were found to have syphilis at delivery. Multivariate analysis showed that women with live-born infants who had less than secondary-level education, who did not watch television during the week before delivery (this was used as an indicator of socioeconomic status), who had a previous history of syphilis, or who had more than one partner during the pregnancy were at increased risk of syphilis. While 76% of the study population had received prenatal care, only 17% had syphilis testing carried out during the pregnancy; 91% of serum samples that were reactive to rapid plasma reagin (RPR) tests were also reactive to fluorescent treponemal antibody-absorption (FTA-ABS) testing. There was 96% agreement between the results from local hospital laboratories and national reference laboratories in their testing of RPR reactivity of serum samples. Congenital syphilis infection was confirmed by laboratory tests in 15% of 66 infants born to women with positive RPR and FTA-ABS testing. CONCLUSION: These results indicate that a congenital syphilis prevention programme in Bolivia could substantially reduce adverse infant outcomes due to this disease.

Analysis of Variance↗
PubMed2001

Wavelet entropy: a new tool for analysis of short duration brain electrical signals.

Since traditional electrical brain signal analysis is mostly qualitative, the development of new quantitative methods is crucial for restricting the subjectivity in the study of brain signals. These methods are particularly fruitful when they are strongly correlated with intuitive physical concepts that allow a better understanding of brain dynamics. Here, new method based on orthogonal discrete wavelet transform (ODWT) is applied. It takes as a basic element the ODWT of the EEG signal, and defines the relative wavelet energy, the wavelet entropy (WE) and the relative wavelet entropy (RWE). The relative wavelet energy provides information about the relative energy associated with different frequency bands present in the EEG and their corresponding degree of importance. The WE carries information about the degree of order/disorder associated with a multi-frequency signal response, and the RWE measures the degree of similarity between different segments of the signal. In addition, the time evolution of the WE is calculated to give information about the dynamics in the EEG records. Within this framework, the major objective of the present work was to characterize in a quantitative way functional dynamics of order/disorder microstates in short duration EEG signals. For that aim, spontaneous EEG signals under different physiological conditions were analyzed. Further, specific quantifiers were derived to characterize how stimulus affects electrical events in terms of frequency synchronization (tuning) in the event related potentials.

Adult↗
PubMed2001

Detection of Streptococcus pneumoniae antigen by a rapid immunochromatographic assay in urine samples.

STUDY OBJECTIVES: Evaluation of a newly available rapid (15 min) immunochromatographic membrane test (ICT) to detect Streptococcus pneumoniae in urine samples, in order to assess its utility in the diagnosis of bacteremic and nonbacteremic pneumococcal pneumonia. DESIGN: Retrospective study. SETTING: We studied urine samples from 51 patients with bacteremic and nonbacteremic pneumonia due to S pneumoniae diagnosed by blood culture and pneumococcal polysaccharide capsular antigen detection by counterimmunoelectrophoresis in urine samples, 16 patients with probable pneumococcal pneumonia, 71 patients with nonpneumococcal pneumonia, and 16 patients with pneumonia but no pathogen identified. Urine samples were collected and frozen at - 20 degrees C until used. The ICT test was performed following the instructions of the manufacturer. MEASUREMENTS AND RESULTS: S. pneumoniae antigen was detected in 41 of 51 patients with pneumococcal pneumonia (80.4%); results were positive in 23 of 28 bacteremic cases (82.1%) and in 18 of 23 nonbacteremic cases (78.3%). From patients with a diagnosis of presumptive pneumococcal pneumonia, antigen was detected in seven urine samples (43.7%) and also in one case of the 16 patients with pneumonia but no pathogen identified. The specificity of the ICT test was 97.2%. CONCLUSION: The ICT assay is a valuable tool for the diagnosis of pneumococcal pneumonia, especially for the nonbacteremic cases.

Adolescent↗
PubMed2000

Postsurgical pleurodesis with autologous blood in patients with persistent air leak.

BACKGROUND: Persistent air leak after operation on the lung is one of the most common problems encountered by thoracic surgeons. We present 6 patients who underwent pleurodesis with autologous blood for persistent air leak after operation. METHODS: Between June 1993 and January 1998, pleurodesis with autologous blood was performed in 6 patients who had air leak of more than 10 days' duration after operation for non-small cell lung cancer. A sample of peripheral blood was taken from the patient's arm and immediately introduced into the chest tube with no additives. The chest tube was left unclamped and off suction, connected to the waterseal drainage, and kept 60 cm above the patient's chest. The next day, the waterseal and chest roentgenogram were reviewed before the chest tube was removed. RESULTS: A persistent air leak with a mean duration of 16.7 days was observed after the initial operation. Fifty to 250 mL of blood was introduced one time into the chest tube. No patient experienced pain, respiratory difficulty, fever, or episodes of coughing during the procedure. After 24 hours, no air leak was detected in the waterseal drainage in any patient. CONCLUSIONS: On the basis of these preliminary findings, we believe pleurodesis with autologous blood is a safe and effective method for treating persistent air leak after a thoracic surgical procedure.

Adult↗
PubMed1999

The Ground and First Torsional States of CD(3)CHO.

The rotational spectra for the ground and first excited torsional states v(t) = 0 and 1 in the frequency region of 8-254 GHz and the v(t) = 1 <-- 0 band high-resolution far-infrared spectrum of 2,2,2-d(3)-acetaldehyde (CD(3)CHO) were measured. We fitted a data set consisting of 1016 v(t) = 1 <-- 0 far-infrared lines together with 195 microwave lines in v(t) = 0 and 79 microwave lines in v(t) = 1 to near-experimental accuracy, using a global model from the earlier literature. The final fit includes lines with J </= 20 and requires 25 parameters to achieve root-mean-square deviations of 87 and 88 kHz for the microwave v(t) = 0 and 1 lines, respectively, and of 0.00048 cm(-1) for the far-infrared v(t) = 1-0 lines. This can be considered a good starting point for future analysis of CD(3)CHO. Copyright 1999 Academic Press.

Journal Article↗
PubMed1998

Sensitivity models in simulation of capillary zone electrophoresis: the effect of buffer power and initial buffer concentration.

Separation of proteins by capillary zone electrophoresis in an amphoteric medium is investigated by numerical simulation. We explain how sensitivity models can be used to gain further information about this process. The sensitivity models that are derived are used to study the sensitivity of the separation to the specific buffer capacity of the amphoteric molecule that serves as a buffer. The effect of changing the overall concentration of this ampholyte is also examined and it is shown that a change in its concentration is equivalent to a change in its buffer capacity.

Buffers↗
PubMed1997

Searching for hidden information with Gabor Transform in generalized tonic-clonic seizures.

The analysis of generalized tonic clonic seizures is usually difficult with scalp EEG due to muscle artifact. We applied Gabor Transform to evaluate 20 seizures from 8 consecutive patients admitted for video-EEG monitoring. We studied the relative intensity ratios of alpha, theta and delta bands over time. In 14/20 events we found a significant decremental activity in the delta band at the onset of the seizure indicating that this is dominated by theta and alpha bands. We conclude that GT is a useful auxiliary tool in the analysis of ictal activity that sheds light on the underlying pathophysiological mechanisms.

Adult↗
PubMed1996

Protein separation by electrophoresis in a nonsieving amphoteric medium.

A numerical model has been used to study the separation of protein mixtures by zone electrophoresis in a nonsieving amphoteric medium. An amphoteric buffer fixes the pH of the solution close to its isoelectric point, where the buffer molecules are unchanged: they thus contribute very little to the conductivity of the solution. This means that high field strengths can be used for rapid separation without sacrificing resolution. The numerical study shows that in this process the band spreading that can reduce resolution is essentially due to differences in migration rate between protein-rich and low-protein zones: both differences in solution conductivity and in protein mobility are involved. Rules for judging the buffer capacity of amphoteric molecules are presented and it is shown how, for a given protein, the effectiveness of this technique varies with the range of pH in which it is applied.

Animals↗
PubMed1994

[An adenocarcinoid tumor of the vermiform appendix].

Goblet cell carcinoids of the vermiform appendix are uncommon. A comprehensive review of the literature revealed about 100 reported cases. Clinical presentation included: asymptomatic patients, acute appendicitis, and/or chronic intermittent lower abdominal pain with or without a palpable mass. We report the case of a 57 year-old woman with lower abdominal pain, nausea and vomiting. Normal blood tests. X-ray of the abdomen showed dilated small bowel loops with fluid levels. Initially, conservative treatment was started. After three days with no clinical improvement, the patient was operated on. An appendicocecal inflammation was found and a terminal ileum plus cecal resection with an end-to-side anastomosis was performed. The pathological diagnosis was goblet cell carcinoid. The patient shows no evidence of recurrence after 1 year follow-up.

Appendiceal Neoplasms↗