Biomedical subjects

C Andreu

Publications and source records attributed to C Andreu.

7 recordsLinked to original sources

PubMed2004

Epidemiological relatedness of methicillin-resistant Staphylococcus aureus from a tertiary hospital and a geriatric institution in Spain.

From January 2000 to June 2002, 24 Staphylococcus aureus isolates were recovered from decubitus ulcers of patients in a geriatric institution, of which 17 (70.8%) were methicillin-resistant S. aureus (MRSA). Antibiotic resistance and DNA macrorestriction (pulsed-field gel electrophoresis; PFGE) patterns of the MRSA isolates were compared with a collection of 161 MRSA isolates from patients admitted to the institution's reference hospital. PFGE revealed the presence of five clonal types (found also in hospitalised patients) among the 17 MRSA isolates. The findings suggest nosocomial acquisition of the MRSA strains by five patients, with subsequent dissemination of the strains within the institution. The high rate of MRSA highlights the need for epidemiological analysis to control the dissemination of MRSA in long-term care facilities.

Aged↗

PubMed2001

Influence of remote substituents on the equatorial/axial selectivity in the monooxygenation of methylene C--H bonds of substituted cyclohexanes.

The reactivity of individual C--H bonds in the methyl(trifluoromethyl)dioxirane TFDO oxygenation of stereogenic methylene groups in conformationally homogeneous monosubstituted cyclohexanes (2) has been determined. The unexpectedly high occurrence of O-atom insertion into C--H(ax) bonds suggests an in plane trajectory attack in the oxygenation while the diastereoselectivity of the reaction is qualitatively interpreted on the basis of the distinct hyperconjugative stabilization by the substituent of diastereomeric transition states due to long-range through bond interactions.

Journal Article↗

PubMed2000

Hyperconjugative Control by Remote Substituents of Diastereoselectivity in the Oxygenation of Hydrocarbons.

The oxidation of 2-substituted adamantanes (2) with TFDO (1) is reported. The data show a stereodifferentiation of the chemical environments induced by remote electron-withdrawing substituents which produces remarkable Z/E diastereoselectivity in the oxidation of the tertiary C(5)-H and C(7)-H bonds. The results show a bell-shaped correlation between the Z/E stereoselectivity and the substituent constant sigma(I), which is interpreted in terms of hyperconjugative stabilization of the diastereomeric transition states.

Journal Article↗

PubMed1998

Regulation of follicular luteinization by a gonadotropin-releasing hormone agonist: relationship between steroidogenesis and apoptosis.

The purpose of this study was to evaluate the effects of GnRH-analog (Leuprolide acetate, LA) administration on follicular luteinization in equine chorionic gonadotropin plus human chorionic gonadotropin (eCG + hCG)-superovulated prepubertal treated rats. Results indicate that LA treatment decreases circulating levels of progesterone (P) and P accumulation in collagenase-dispersed ovarian cell cultures, though estradiol (E2) production is increased. These data suggest that cells from the LA group may be less luteinized following gonadotropin treatment. Studies performed on histological ovarian sections after different times of eCG administration showed that LA injections produce lower amounts of corpora lutea and antral follicles, and a greater number of atretic and preantral follicles. The basal and LH-stimulated P and progestagen accumulations are decreased in incubations of corpora lutea isolated from the LA group. In addition, the mitochondrial cholesterol side-chain cleavage (P450SCC) levels in corpora lutea from LA-treated rats are reduced, indicating that the decrease in P production observed is due in part to an alteration in the steroidogenic luteal capability. Immunocytochemical localization of nuclei exhibiting DNA fragmentation by the technique of terminal deoxynucleotidyl transferase end-labeling showed that LA treatment causes an increase in the number of apoptotic cells in preantral and antral follicles at all times studied (1, 2, 4, or 7 days of LA administration). A similar effect, though less pronounced, was observed in corpora lutea. It is concluded that LA treatment produces a failure in the steroidogenic luteal capability and an increase of apoptotic mechanisms in the ovary, producing as a consequence an interference in the follicular recruitment, growth, and luteinization induced by gonadotropins.

Animals↗

PubMed1997

[Regulation of follicular luteinization by an agonist of gonadotropin-releasing hormone (GnRH)].

Long treatments with GnRH agonist are used in patients to suppress the endogenous secretion of gonadotropins, however; these analogs have a direct effect on the ovary. The aim of this work was to study the in vivo effect of the GnRH analogue, leuprolide acetate (LA) on ovarian steroidogenesis and apoptosis mechanisms. LA (1 microgram/rat/day) was injected to PMSG/hCG superovulated rats. Corpora lutea were isolated by microdissection and incubated (4/0.5 ml) during 3 h with LH (10 ng/ml) or dibutyryl cAMP (dcAMP 1 mM). Progesterone production was measured observing in LA treated rats a decrease in basal and LH stimulated values (Basal = Control C: 96.6 +/- 9.6; LA: 22.9 +/- 2.8; LH = C: 145.7 +/- 4.9; LA: 23.6 +/- 2.0 ng/ml, p < 0.001). In contrast, dcAMP stimulated significantly both groups (C: 153.9 +/- 11.8; LA: 83.15 +/- 8.2). cAMP production was lower in LA corpora lutea and LH was not able to stimulate them (Basal = C: 7.29 +/- 1.6; LA: 1.17 +/- 0.6; LH = C: 13.2 +/- 0.4; LA: 2.5 +/- 0.4 ng/ml, p < 0.01). Corpus luteum of both groups showed similar protein content. On the other hand, taking into account that in ovarian histological slides of LA treated rats we observed more atresic follicles and less corpora lutea, we determined the amount of apoptotic cells. The criterion used was the presence of apoptotic bodies and nuclear chromatin aggregated in dense masses beneath the nuclear envelope. An increase of apoptotic cells in the LA group ovaries was detected. This result was confirmed by immunohistochemical technics (TUNEL). It was concluded that LA treatment produces in ovarian cells a failure in the LH receptor-adenilate cyclase system and an increase in cellular apoptosis.

Animals↗

PubMed1994

Quantitative EEG in children with headache.

The object of this work is to determine if Brain Mapping can reveal significant differences between a normal control group and a group whose members suffer from one of three types of headache: tension-type, migraine with aura and migraine without aura. Both groups were formed by children aged between 6 and 14; the latter were undergoing no treatment and were in a headache-free phase. Results demonstrate that there are no significant differences between the control group and the tension-type headache group. Neither were differences found in migraine without aura group but in migraine with aura there was an increase of the theta/alpha ratio in the temporal posterior and occipital zones. This ratio could be used as a neurophysiological indicator in the evolution of the migraine with aura pathology.

Adolescent↗

PubMedDate not supplied

Tolerance of a Salsola kali extract standardized in biological units administered by subcutaneous route. Multicenter study.

BACKGROUND: Sensitivity to Salsola kali is a frequent cause of allergic respiratory disease in various regions of Spain. However, there are very few articles in which this allergen has been studied. METHODS AND RESULTS: In order to evaluate the tolerance of this extract, a prospective study has been performed. This study was observational, multi-centred and open, involving 88 patients with allergic respiratory disease due to sensitivity to Salsola, aged between 5 and 52 years. The administration of the extract was performed subcutaneously, through one of two treatment schedules: cluster (8 doses in 4 visits) or conventional (13 doses in 12 visits). A total of 42 adverse reactions were registered, in 26 patients (35 local reactions in 21 patients and 7 systemic reactions in 6 patients). Among the 7 systemic reactions, 4 were registered with the cluster protocol and 2 with the conventional protocol (p = 0.329). In no patients were serious adverse reactions registered. CONCLUSION: The subcutaneous administration of a Salsola extract is safe and well tolerated, both when administered using a conventional schedule and when using a cluster schedule.

Adolescent↗