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Biomedical subjects

C Blanco

Publications and source records attributed to C Blanco.

161 records · Page 9Linked to original sources
PubMed1982

Cloning and endonuclease restriction analysis of uidA and uidR genes in Escherichia coli K-12: determination of transcription direction for the uidA gene.

The two genes of the Escherichia coli K-12 uid region (the structural gene uidA and the regulatory gene uidR) were isolated on a ColE1-uid hybrid plasmid from the bank of Clarke and Carbon. We made a restriction map of this region and correlated it with the genetic map by subcloning the uid restriction fragments into plasmids pBR322, pBR325, and pACYC177. In these plasmids, amplification of the products of the uidA and uidR genes occurred. The enzyme coded for by uidA was identified by polyacrylamide gel electrophoresis of crude extracts from strains containing the uidA plasmid. A 1-megadalton EcoRI-BamHI segment contained the uidAo operator, and the direction of transcription of the uidA gene was determined. The restriction analysis also suggested that the order of the loci in this region is manA, uidA, uidAo, uidR.

Cloning, Molecular↗
PubMed1979

New endotracheal tube adaptor reducing cardiopulmonary effects of suctioning.

The continuous recordings of arterial oxygen saturation (SaO2) and beat-to-beat heart rate before, during, and after tracheobronchial suctioning were studied in eight preterm infants with severe RDS receiving mechanical ventilation. Two suctioning procedures were alternatively performed in each infant; In procedure A, disconnection of the ventilator and preoxygenation preceded suctioning; in procedure B, a special suction adaptor was used without ventilatory interruption or preoxygenation; 128 suctionings were performed with each procedure and the changes in heart rate (HR) and SaO2 during suctioning were compared. Although in both procedures, HR and SaO2 decreased during suctioning, the degree of bradycardia and arterial blood oxygen desaturation were significantly smaller in magnitude and shorter in duration during procedure B. These data indicate advantages of the suction adaptor in minimizing bradycardia and hypoxia from airway suction.

Bronchi↗
PubMed1979

Baroreceptor and chemoreceptor responses to umbilical cord occlusion in fetal lambs.

11 fetal lambs with gestational age of 116-135 days were studied while connected to a membrane-oxygenator replacing the ventilatory function of the placenta. Progressive increase in arterial oxygen tension from 20 to 220 mm Hg resulted in progressive decrease in baseline heart rate and baseline arterial blood pressure indicating presence of chemoreceptor activity over this wide range of arterial oxygen tension. The effect of 60 sec complete umbilical cord occlusion was studied at progressively higher arterial oxygen tension and it was concluded that the chemoreceptor activity at fetal normoxic condition is very brisk and is markedly attenuated at hyperoxic levels. Although it was not possible to completely separate baroreceptor and chemoreceptor reflexes involved in cardiovascular response to umbilical cord occlusion, it is postulated that the chemoreceptor and baroreceptor reflexes are complimentary during cardiovascular responses to umbilical cord occlusion.

Animals↗
PubMed1976

Incidence and clinical features of patent ductus arteriosus in low-birthweight infants: a prospective analysis of 150 consecutively born infants.

The incidence of persistent patency of the ductus arteriosus beyond the third day of life was prospectively determined in 100 preterm infants with birthweights of 2,000 gm or less and 50 infants with birthweights of 2,001 to 2,500 gm. The overall incidence was 21% and was inversely related to increasing gestational age and birthweight. The data suggest that immaturity is the major determinant of the persistent patency of the ductus arteriosus. Spontaneous delayed closure of the ductus occurred in 79% of patients that survived the immediate neonatal period. There was a high degree of association between the presence of a patent ductus arteriosus (PDA) and respiratory distress syndrome (RDS). Eight infants with severe RDS and PDA developed heart failure and four required surgical ligation of the ductus. None of the infants with birthweights greater than 2,000 gm who had PDA developed heart failure or required surgical ligation of the ductus arteriosus.

Birth Weight↗
PubMedDate not supplied

Prophage distribution in coryneform bacteria.

Four temperate bacteriophages of corynebacteria were isolated after UV induction. Phages phi 304L and phi 304S were both induced from Corynebacterium glutamicum ATCC 13058, ATCC 21488, ATCC 21649 and ATCC 21650 strains, and have no known sensitive host. Phages phi 15 and phi 16 were both induced from ATCC 14020 and ATCC 21792. Phage phi 15 formed turbid plaques on Corynebacterium sp. ATCC 21857 and on C. glutamicum ATCC 13058, ATCC 21488, ATCC 21649 and ATCC 21650. Phage phi 16 produced turbid plaques only on C. glutamicum ATCC 21792 cured of prophage phi 16. All these phages belong to the Siphoviridae family. Their genomes consist of a double-stranded DNA with cohesive ends and share no homology with each other. Prophages phi 16, phi 304L and phi 304S were integrated into their respective host chromosomes, whereas prophage phi 15 seemed to persist free in the cell. Cross-hybridizations between phage DNAs and total cellular DNA obtained from 20 strains belonging to the genera Corynebacterium and Brevibacterium did not show the presence of these prophages in strains other than their respective hosts.

Bacteriophages↗
PubMedDate not supplied

Chaos theories and therapeutic commonalities among depression, Parkinson's disease, and cardiac arrhythmias.

This report reviews and compares all therapies that have shown efficacy in depression and Parkinson's disease, although some are not in current use and others are at the experimental stage. They include pharmacological modification of neurotransmitter pathways, electroconvulsive therapy (ECT), sleep deprivation, psychosurgery, electrical stimulation through cerebral electrodes, and transcranial magnetic stimulation. Stemming from a pathophysiological model that stresses the brain as an open, complex, and nonlinear system, all therapies have been attributed a common mechanism of action. This report suggests that the therapeutic isomorphism is related to their ability to help the CNS deactivate cortical-subcortical circuits that are dysfunctionally coupled. These circuits are self-organized among neurons of their informational subsystem (rapid conduction) and modulating subsystem (slow conduction). Finally, this report extends the analysis and comparison of these therapies to some cardiac arrhythmias.

Arrhythmias, Cardiac↗
PubMedDate not supplied

The Maastricht Cerebral Monitor (MCM) for the neonatal intensive care unit.

Although long-term monitoring of cerebral activity can be important in neonatal intensive care, the complexity of multi-channel EEG makes it less suitable for this purpose. In the past, a cerebral function monitor (CFM) was developed that analyses EEG. The output parameter of the CFM is a semi-logarithmic amplitude distribution resulting from the amplification, bandpass filtering, compression, rectification and smoothing of the single-channel EEG. Drawbacks of the CFM include its inflexibility and limited single-channel processing capacity and its lack of functionality for data storage, review or re-analysis. Modern computers are powerful enough that a system can be built which does not have these drawbacks. We have developed such a system: the Maastricht Cerebral Monitor (MCM). The MCM is a flexible system that not only overcomes the CFM drawbacks but also provides advanced signal analysis. It was developed with a software system (Poly) for acquisition, high quality real-time display, on-line analysis and storage of physiological signals. The MCM processes three EEG signals in the amplitude and frequency domains. Other parameters provided by the MCM are asymmetry of absolute frequency powers, percentage suppression, mean and 90% spectral edge frequency. Electrode impedance is recorded as a measure of quality of the recording.

Brain↗
PubMedDate not supplied

Long-term and short-term variations in amplitude and frequency of spontaneous otoacoustic emissions in pre-term infants.

In pre-term infants, spontaneous otoacoustic emission (SOAE) frequencies show an upward shift with time. The present study aimed to monitor the SOAE amplitude variation during this frequency shift. A long-term observation of 87 SOAE frequencies from 18 pre-term infants yielded a positive frequency shift of 0.72 per cent per week, which was not accompanied by a simultaneous amplitude shift, as the mean variations in SOAE amplitude were practically zero. Furthermore, there was no relationship between the short-term SOAE amplitude variation and the infant's post-conceptional age. Only the absolute amount of SOAE amplitude variation seemed to grow with time. Comparison with induced variations in SOAE frequency argues against a middle ear influence on the SOAE frequency shift. In our view, the absence of any amplitude shift during the upward SOAE frequency shift further suggests cochlear development during the last period of gestation.

Age Factors↗
PubMedDate not supplied

[Molecular characterization of aphthous fever virus isolated during the years 1993-1994 in Argentina].

Nucleotide sequence and phylogenetic analysis of the VP1 structural protein have been used extensively as diagnostic and epidemiological tools for foot and mouth disease virus (FMDV). In this report we have applied this methodology to the analysis of the VP1 coding sequence from FMDV strains isolated in Argentina during 1993-1994. The results demonstrated that the field isolates were related to the vaccine strains used at that time. However the involvement of the vaccine virus appeared to be different for outbreaks caused by FMD viruses type O or C. These data provide a database essential for determining the origin of new epizootics.

Animals↗
PubMedDate not supplied

Shellfish hypersensitivity: clinical and immunological characteristics.

Shellfish is one of the most frequent causes of food allergy. We studied 48 patients (25 male and 23 female) with a mean age of 24.2 +/- 1.8 with shellfish hypersensitivity. A clinical questionnaire was carried out and prick tests were performed using a series of aeroallergens and a battery of extracts of squid, shrimp, lobster, crab, mussel and clam. Prick tests were also performed using raw and boiled extracts from fresh squid, octopus and limpet. Total and specific IgE to these allergens were determined. The most frequent causes of symptoms were shrimp (33 cases) and squid (24 cases). The most frequently found symptoms were Urticaria/angioedema (39 patients), asthma (18 patients) and rhinitis (14 patients). Clinical association was found between Cephalopoedae and Lamelibranquiae (p < 0.05 for clam and p < 0.01 for mussel), but not among both groups and Crustaceans. Association between history and Prick was statistically significant for Crustaceae and Cephalopoedae (p < 0.01) but not for Lamalibranquiae. Association between history and CAP was not found for shellfish. Significant differences among prick-tests with raw and boiled extracts were not found. These results suggest that prick test yields better results than CAP does it, in shellfish hypersensitivity, that clinical association among shellfish hypersensitivity can occurs within the same and different Phylum reflecting common epitopes and that squid, octopus and limpet extracts contain a large amount of heat-stable allergens.

Adolescent↗
PubMedDate not supplied

Nasal candidiasis in an immunocompetent patient.

We report a case of nasal candidiasis in an immunocompetent host who denied the use of topical or systemic corticosteroids. The patient was treated with itraconazole 100 mg. with resolution of the symptoms.

Adult↗
PubMedDate not supplied

Food hypersensitivity among adult patients: epidemiological and clinical aspects.

Food hypersensitivity (FH) is lesser frequent among adult patients than in childhood. Foods implicated in hypersensitivity reactions vary with sociocultural and diet habits from a geographic place to other. We studied 142 adult patients sensitized to foods, among 7698 patients visited at our Outpatient Clinic. Hundred and twenty patients referred clinical symptoms after consumption of one or more foods consistently. From the latest, 107 patients (89.2%) were atopics (92 of them sensitizes to dust mites) and 54 (45%) referred atopic familiar background. Most frequent recorded symptoms were: urticaria/angioedema 84 cases (70%), oral syndrome 65 (54%), asthma 48 (37%) and anaphylaxis 33 patients (27.5%). Shellfish sensitization occurred in 50 patients, fresh fruits in 33 and nuts in 29 cases. Shrimp (48 patients), squid (33), kiwi (14), papaya (14), avocado (13) and banana (12 cases) were the most frequent causes of FH. Significant statistical association between foods and inhalants was observed for fresh fruits and latex (p < 0.001), fresh fruits and pollens (p < 0.01), and shellfish and Blatta germanica (p < 0.001). Prevalence of FH among patients at our Area is around 1.6%. Tropical fruits, as other kind of fruits, seem to share common IgE-epitopes to pollens. High prevalence of shellfish and cockroach hypersensitivity could be more easily developed by previous domestic mites sensitization.

Adult↗