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Biomedical subjects

B Orden

Publications and source records attributed to B Orden.

At least 19 recordsLinked to original sources
PubMed2002

Sexual responses to intrauterine stress: body and brain growth.

The aims of this work were to analyse body and brain growth as produced by deficiencies in the uteroplacental blood supply, and to evaluate sexual responses to intrauterine stress. Intrauterine growth retardation (IUGR) was experimentally induced in pregnant rats by partial obstruction in both uterine vessels at 1,7 and 14 gestational days. The dysfunctions in the placental circulation retarded both somatic and cerebral growth, depending on the period of gestational stress and the sex. Brain weight had a relatively greater resistance than body weight, which is called a "brain sparing" mechanism. The body and brain sexual dimorphism in control pups was inhibited in IUGR pups. This study shows that prenatal stress exposition might modify growth and sexual dimorphism at birth.

Adaptation, Physiological↗
PubMed2002

Effects of bilateral uterine vessel ligation on skeletal growth in rats.

The aim of the present study was to assess the catch-up growth in the postcranial skeleton of intrauterine growth retarded (IUGR) rats. Male and female Wistar rats were assigned to one of the following groups: controls, sham-operated, IUGR. The IUGR was produced by uterine vessels bending (day 14th of pregnancy). Trunk, pelvis, femur and humerus were measured on Rx of each animal, from I to 84 days of age. Data were processed by repeated analysis of variance and LSD post hoc test. The reduced placental blood flow disturbed the skeletal growth in pups, with the axial skeleton relatively more affected than the bones of the extremities. The catch up only took place in femur length of both sexes. The widths of long bones remained significantly retarded. We concluded that nutritional rehabilitation during the postnatal period might not be enough to allow a complete growth recovery.

Animals↗
PubMed1998

Erythromycin resistance of Streptococcus pyogenes in Madrid.

BACKGROUND: Erythromycin is considered to be an adequate alternative to penicillin for patients who are allergic to penicillin. Erythromycin-resistant Streptococcus pyogenes strains have been reported in some parts of the world. METHOD: The in vitro activity of erythromycin and other antimicrobial agents was determined in a total of 1310 clinical Streptococcus pyogenes isolates collected in the city of Madrid from January, 1993, through December, 1996. RESULTS: All strains showed susceptibility to penicillin, rifampin, vancomycin and chloramphenicol. Tetracycline resistance was 8.5%. In 36 of the strains (2.7%) MIC was 4 microg/ml for ofloxacin. Clindamycin resistance was observed in only 18 strains (1.4%); this resistance was constitutive in 15 and inducible in 3 strains. Resistance to erythromycin was observed in 14.3% of the strains, showing an increase during the study period (2.0% in 1993 vs. 22.4% in 1996; chi square for linear trend 68.8, P < 0,0001); >90% of them showed the novel resistance phenotype described by Seppälä et al. and 32 of 32 of these strains showed by PCR the 1.4-kb fragment of the mefA gene recently described as the novel macrolide efflux resistance determinant. The erythromycin-resistant strains were isolated more often in pediatric patients (144 of 872) than in adults (44 of 438) (chi square 9.9, P = 0.0016). CONCLUSION: The study emphasizes the need to screen for resistance to macrolides in S. pyogenes and indicates that resistance to erythromycin in S. pyogenes has increased significantly in Madrid.

Adolescent↗
PubMed1996

[Antibiotic resistance to erythromycin, clindamycin and tetracycline of 573 strains of Streptococcus pyogenes (1992-1994)].

BACKGROUND: The aim of this study was to know the antibiotic resistence of Streptococcus pyogenes to erythromycine, clindamycine and/or tetracycline in community samples. The second aim was to determine the existence of multiresistant strains and to know the relationship between resistant strains, clinical samples and age of the patient. METHOD: A retrospective analysis was performed in all the strains of S. pyogenes isolated from January 1992 to December 1994. Antibiotic sensitivity was studied by MIC by the microdilution method using the Pasco semiautomatic system. RESULTS: During the study period 573 beta hemolytic streptococci were identified as S. pyogenes. The global resistance to erythromycine (2.8%), clindamycine (1.4%) and tetracycline (7.3%) remains at low levels but has significantly increased in the case of erythromycine (p < 0.05) and tetracycline (p < 0.05) over these 3 years. The incidence of strains resistant to clindamycine has also increased slowly although this rise is not significant. Five strains (0.9%) were not sensitive to the three antibiotics studied, 4 being isolated in the last trimester of 1994 in pharyngeal exudates. S. pyogenes resistant to erythromycine was most frequently isolated from cutaneous lesions and in pediatric patients (under the age of 14 years). CONCLUSIONS: These results confirm the trend towards an increase in the number of strains of S. pyogenes resistant to erythromycine, clindamycine and/or tetracycline, being most often found in cutaneous lesions and pediatric patients.

Anti-Bacterial Agents↗
PubMed1993

Evaluation of a colour test for rapid detection of Salmonella.

The performance of a colour test (Wellcolex) for rapid detection of the most frequently isolated O serogroups of salmonella (A, B, C, D, E/G) and the Vi antigen was evaluated using colonies grown on enteric differential agar media and in selenite broth. The test had excellent sensitivity (100%) and specificity (100%) with colonies taken directly from primary culture plates. Initial tests in selenite broth showed limited sensitivity (62.1%) but by using high quality media and modifying the inoculation procedure, sensitivity was greatly improved (99%).

Bacteriological Techniques↗