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Biomedical subjects

A Valero

Publications and source records attributed to A Valero.

At least 19 recordsLinked to original sources
PubMed2003

Malaria in Mauritania: the first cases of malaria endemic to Nouakchott.

The current situation of endemic malaria in Mauritania is not clear since, in most health centres, suspected malaria cases are not confirmed by parasitological analysis and diagnosis is based on clinical symptoms alone. To obtain reliable data about malaria in this country, thin and thick blood smears were taken from patients with symptoms compatible with the illness, who attended two hospitals: Polyclinic of Nouakchott, which serves one-third of the country's population, where a malaria infection rate of 18.5% (77 of 446) was recorded; Plasmodium falciparum caused 61.85% of these, P. vivax 35.5% (28/77). In Kaedi Regional Hospital, provincial capital of the endemic Gorgol region, a prevalence of 25.49% (106 of 416) was recorded, with P. falciparum as the sole pathogenic species. Of the 77 cases of malaria diagnosed in Nouakchott, nine (seven of P. falciparum and two of P. vivax) were considered as endemic to the city. These cases were all children under 8 years of age except for one adult who had never left the capital, and this is the first time that cases endemic to this city have been detected.

Adolescent↗
PubMed2003

Determination of IgE in the serum of patients with allergic reactions to four species of fish-parasite anisakids.

This study investigates cross-reactions between somatic and metabolic antigens of various anisakids in the serum of patients with allergic processes. Twenty patients with allergic reactions after eating fish were studied using the skin-prick test for sensitivity to four species of anisakids. IgE was also determined, by blotting, in the serum of these patients when confronted with somatic and metabolic antigens of Anisakis simplex s.l. and Hysterothylacium aduncum, and somatic antigens of A. physeteris and H. fabri. The results obtained with both techniques basically agree, the following facts being of particular note: four patients presented specific IgE for A. simplex s.l. and 1 for Hysterothylacium sp. only, eight patients presented cosensitivity for A. simplex s.l. and A. physeteris, two for A. simplex s.l. and Hysterothylacium sp., one for A. physeteris and Hysterothylacium sp., and two for A. simplex s.l., A. physeteris and Hysterothylacium sp. Given the results obtained, it should be considered that other species of fish-parasite anisakids, apart from A. simplex s.l., may be involved in the allergic reactions presented by a large number of patients.

Animals↗
PubMed2002

In vitro cultivation of Hysterothylacium aduncum (Nematoda: Anisakidae) from 3rd-stage larvae to egg-laying adults.

This is the first demonstration of the in vitro development of the 3rd-stage larvae (L3) of Hysterothylacium aduncum to the adult. This was achieved in a semi-defined medium that is easy to prepare and to reproduce. The L3, collected from the peritoneal cavity of horse mackerel (Trachurus trachurus), were individually inoculated into RPMI-1640 medium +20% heat-inactivated fetal bovine serum (IFBS). It has been demonstrated that the optimum temperature for development is around 13 degrees C and is stimulated by the presence of 5% CO2 in the growth atmosphere, increasing the percentage moulting to the 4th larval stage (L4) by 1.9-fold (from 44 to 82%) and the average survival of the nematodes by 1.6 times (from 60 to 96 days). When the larvae were grown at different pHs, optimum development occurred at pH 4.0. Under these conditions, all the larvae moulted to the L4 and more than two-thirds transformed to the adult stage--in which 25-30% of the females laid eggs--and reached an average survival of over 4 months. When this medium was supplemented with 1% (w/v) of commercial pepsin, all the larvae reached the adult stage, at least 45% of the females oviposited, laying around 12-fold more eggs per female than in the medium without pepsin. The mean size of the eggs (non-fertilized) obtained was 56.8 x 47.6 microm. The mean length of the adult males obtained was between 3.2 and 5.2 cm and the females were between 3.0 and 6.5 cm. The adult specimens were morphologically identified as Hysterothylacium aducum aduncum. This culture medium (RPMI-1640+20% (v/v) IFBS+1 commercial pepsin, at pH 4.0, 13 degrees C and 5% CO2 in air) could facilitate the identification of at least some of the larvae of the genus Hysterothylacium--and perhaps other anisakids--for which the specific identification and the biological study of these parasites is often difficult.

Aging↗
PubMed2001

In vitro cultivation of anisakis simplex: pepsin increases survival and moulting from fourth larval to adult stage.

This paper describes the in vitro cultivation of the 3rd-larval stage (L3) of Anisakis simplex to adulthood in a much simpler and easier to prepare medium than those described to date. The adult males obtained are between 3.8 and 6.5 cm long and the females between 4.5 and 8.0 cm. Some individually cultivated females laid eggs which had an average size of 44.4 x 50.5 microm. The culture conditions were as follows: medium RPMI-1640 supplemented with 20% heat-inactivated fetal bovine serum and 1% commercial pepsin, at pH 4.0 and a temperature of 37 degrees C, and in air atmosphere with 5% CO2. The pepsin was found to be the key to the success of the culture. The average survival of the worms in the culture increased from 50 to 88 days, due to the fact that the survival of the adults practically doubled (increasing by 1.9 times). Furthermore, the number of worms that completed the 4th moulting (M4) increased by 4.2 times, from 22.9 to 95.6%. This culture medium may facilitate, due to its simplicity, the study of anisakids, or at least of A. simplex, constituting another step towards achieving a complete in vitro life-cycle for these parasites.

Animals↗
PubMed2001

Cardiac involvement in autosomal-dominant polycystic kidney disease: a hypertensive heart disease.

BACKGROUND: There is little information regarding the occurrence and distribution of cardiovascular abnormalities during the course of autosomal-dominant polycystic kidney disease (ADPKD). We conducted a cross-sectional study in three different groups of ADPKD patients to determine the profile and prevalence of cardiac involvement in this population. METHODS: Doppler color echocardiography was performed in 130 ADPKD patients. Patients were divided into normotensive (Group I, n=60), hypertensive (Group II, n=32) and those undergoing hemodialysis (Group III, n=38). RESULTS: There was a progressive increase in left ventricular mass (LVM) index (88.6+/-19.7, 127.6+/-40.4 and 150.5+/-56.5 g/m2, p < 0.0001) and in the prevalence of left ventricular hypertrophy (LVH) (3%, 43%, 62%, p < 0.0001) in Groups I, II and III, respectively. E/A ratio < 1 was found in 2% of normotensives, 46% of hypertensives and 62% of hemodialysis patients (p < 0.0001). Prevalence ofmitral valve prolapse and aortic and/or mitral regurgitation was 4.3% and 8.6%, respectively, in non-dialysis patients. The majority of valvular abnormalities occurred in dialysis patients, and were generally related to annular mitral calcification (28%) or aortic valve calcification (38%). Age, sex, systolic blood pressure (BP) and hemoglobin were independent predictors of LVM index in the entire population, systolic BP and creatinine in non-dialysis patients and systolic BP in dialysis patients. Age, heart rate and diastolic BP in the entire group, and age, heart rate and LVM index in non-dialysis patients remained as independent predictors of abnormal diastolic function. CONCLUSIONS: Cardiac involvement in ADPKD patients is a continuous process that evolves during the course of this disease. It is characterized by a low prevalence of specific valvular abnormalities, a progressive increase in LVM, LVH, and diastolic dysfunction, which are greatest in the latter stages of the disease. This study confirms the major influence of BP on cardiovascular abnormalities of ADPKD patients.

Adult↗
PubMed2000

Polyimide cuff electrodes for peripheral nerve stimulation.

This paper describes a new tripolar spiral cuff electrode, composed of a thin (10 microm) and flexible polyimide insulating carrier and three circumneural platinum electrodes, suitable for stimulation of peripheral nerves. The cuffs were implanted around the sciatic nerve of two groups of ten rats each, one in which the polyimide ribbon was attached to a plastic connector to characterize the in vivo stimulating properties of the electrode, and one without a connector for testing possible mechanical nerve damage by means of functional and histological methods. The polyimide cuff electrodes induced only a very mild foreign body reaction and did not change the nerve shape over a 2-6 month implantation period. There were no changes in the motor and sensory nerve conduction tests, nociceptive responses and walking track pattern over follow-up, and no morphological evidence of axonal loss or demyelination, except in one case with partial demyelination of some large fibers after 6 months. By delivering single electrical pulses through the cuff electrodes graded recruitment curves of alpha-motor nerve fibers were obtained. Recruitment of all motor units was achieved with a mean charge density lower than 4 microC/cm(2) for a pulse width of 50 micros at the time of implantation as well as 45 days thereafter. These data indicate that the polyimide cuff electrode is a stable stimulating device, with physical properties and dimensions that avoid nerve compression or activity-induced axonal damage.

Animals↗
PubMed2000

Larval anisakids parasitizing the blue whiting, Micromesistius poutassou, from Motril Bay in the Mediterranean region of southern Spain.

A total of 301 blue whiting, Micromesistius poutassou Risso, 1826, ranging in length from 17 to 28 cm, from Motril Bay (Mediterranean coast, south Spain) were examined for anisakid nematodes, as these fish are common items in the Spanish Mediterranean diet. Three anisakid species were morphologically identified with a total prevalence of 10.63%. Anisakis simplex s.l. Rudolphi, 1809 had a prevalence value of 6.65%, compared with 2.66% for A. physeteris Baylis, 1923 and 2.33% for Hysterothylacium aduncum Rudolphi, 1802. Variations in prevalence values with season and host size are discussed. Allozyme markers (leucine aminopeptidase-1) were used to identify anisakid nematodes assigned to the A. simplex complex and all examined larvae were found to correspond genetically to A. pegreffii Nascetti et al., 1986.

Animals↗
PubMed2000

The occurrence of two opecoeliid digeneans in Mullus barbatus and M. surmuletus from the Spanish south-eastern Mediterranean.

The infection by Opecoeloides furcatus and Poracanthium furcatum (Opecoeliidae) was studied in 121 Mullus barbatus and 113 M. surmuletus collected from the Spanish south-eastern Mediterranean. The prevalence of infection was most frequent in M. surmuletus with values of 81.42% for O. furcatus and 38.05% for P. furcatum. In M. barbatus the prevalences of O. furcatus and P. furcatum were 54.54% and 14.88% respectively. Statistically significant differences were found between the infection of the two hosts with P. furcatum. No significant differences in worm burdens could be attributable to host size or to seasonal changes, although a lower infection of M. barbatus by O. furcatus occurred in the autumn. Furthermore, the electrophoretic mobility of the enzyme malic dehydrogenase (MDH) was also studied and both digeneans presented different patterns, corresponding in both cases to homozygotic genotypes.

Animals↗
PubMed1999

Early social isolation decreases the expression of calbindin D-28k in rat cerebellar Purkinje cells.

The main objective of this study was to analyze the effects of early social isolation on the expression of calbindin D-28k (CAD-28k) in cerebellar Purkinje cells. Sprague-Dawley rats were reared either in isolation (IC) or socially housed conditions (SC) from postnatal days 18-32. Half of the rats of each group were sacrificed at 32 days of age and the cerebella processed for immunocytochemical labeling against CAD-28k. The remaining IC animals were housed under standard conditions for re-socialization between postnatal days 32 and 62. The results indicate that Purkinje cells of rats reared under early isolation show a marked loss of CAD-28k immunoreactivity, and that this deficiency is recovered by later social interaction, although the thickness of the molecular layer remains reduced.

Animals↗
PubMed1999

Olfactory bulb ensheathing cells enhance peripheral nerve regeneration.

Sciatic nerve resection leaving a 15 mm gap could not be repaired by bridging the stumps with a silicone tube prefilled with a laminin gel. However, when purified olfactory ensheathing cells (EC) were added to the gel filling the tube, successful axonal regeneration was observed in 50% of rats. With 12 mm gaps, regeneration occurred in 79% of rats with transplanted EC compared with 60% of those receiving collagen gel alone. Therefore, ECs help repair severe peripheral nerve injuries, in addition to their ability to promote axonal regeneration within the central nervous system.

Action Potentials↗
PubMed1999

Physiological and immunohistochemical characterization of cisplatin-induced neuropathy in mice.

We investigated the neuropathic effects of cisplatin in two groups of mice treated with 5 or 10 mg/kg/week of cisplatin for 7 or 8 weeks. Peripheral nerve functions were evaluated by sweat imprints, and electrophysiological, rotarod, and nociceptive tests. Protein gene product 9.5 (PGP), calcitonin gene-related peptide (CGRP), and vasoactive intestinal peptide (VIP) were immunohistochemically localized in footpads. Tibial nerves were analyzed morphometrically. Functional deficits developed progressively with higher cumulative doses, more markedly in mice treated with high than in those with low doses. From cumulative doses of 10 mg/kg, significant declines in sensory nerve conduction velocity and sudomotor responses were found, whereas motor and nociceptive functions were involved later. There were no morphometrical changes in tibial nerves. A marked decrease of CGRP- and VIP-immunoreactive nerves occurred in samples from treated mice, whereas PGP-labeled profiles decreased mildly at late stages. Impairment of the content of neuropeptides with neurosecretor role was detectable earlier than functional abnormalities. Immunohistochemical analysis of skin biopsies offers a useful diagnostic tool for peripheral neuropathies.

Animals↗
PubMed1999

Ensheathing glia transplants promote dorsal root regeneration and spinal reflex restitution after multiple lumbar rhizotomy.

Previously, we have shown that transplants of olfactory bulb ensheathing cells promoted regeneration of transected dorsal roots into the spinal cord. In this study, we assessed the ability of regenerating axons to make functional connections in the cord. Dorsal roots L3 to L6 were sectioned close to their entrance into the spinal cord and reapposed after injecting a suspension of ensheathing cells into each dorsal root entry zone (Group G). Afferent regeneration into the cord and recovery of spinal reflexes were compared with animals that received no injection (Group S) or culture medium without cells (Group C). Electrophysiological tests, to measure nerve conduction and spinal reflexes (H response and withdrawal reflex) evoked by stimulation of afferents of the sciatic nerve, were performed. At 14 days after surgery, H response was found in only 1 of 7 rats of Group G, and withdrawal reflexes were absent from all animals. At 60 days, the H response reappeared in 7 of 10 rats of Group G, and 1 of 5 of each of Groups C and S. The withdrawal reflex recovered in 4 of 10 rats of Group G, but in none of Groups C and S. Immunohistochemical labeling for calcitonin gene-related peptide (CGRP) in rats of Group G showed immunoreactive fibers entering the dorsal horn from sectioned roots, although at lower density than in the contralateral side. In conclusion, transplanted ensheathing cells promoted central regeneration and functional reconnection of regenerating sensory afferents.

Animals↗
PubMed1999

[Comparative study of three systems for in vitro activity investigation of fluconazole against yeast isolates of clinical interest].

BACKGROUND: Study of antifungal sensitivity can help in treatment screening and evaluation of patients suffering from some fungal infections. The purpose of this study is to compare fluconazole MICs obtained by E-test and agar dilution with the NCCLS method. MATERIAL AND METHODS: The in vitro activity of fluconazole against 158 yeast strains by three systems: E-test, agar dilution and the microbroth NCCLS M27P method. RESULTS AND CONCLUSION: A correlation between 84 to 100% was observed the degree varying in the result among different species. The E-test was found to be comparable to the NCCLS M27P microbroth method, was easier to perform and provides MIC result for Candida species within 24 h.

Antifungal Agents↗
PubMed1998

Changes in cholinergic responses of sweat glands during denervation and reinnervation.

Functional sudomotor responses have been studied in sweat glands reinnervated after sciatic nerve crush and partially denervated by cisplatin intoxication in the mouse. The sudomotor function mediated by the sciatic nerve was evaluated by silicone imprints on the plantar surface of the hindpaws. Five days after nerve crush, completely denervated sweat glands became unresponsive to cholinergic stimulation with pilocarpine. During the following weeks, the number of reinnervated, reactive sweat glands increased progressively to reach a maximum of 89% of preoperative control counts by 40 days after nerve crush. At this time, the mean volume of sweat secreted per gland was normal, but reinnervated glands showed a secretory activity abnormally sustained over time after pilocarpine stimulation and, on the other hand, had an increased resistance to the inhibition of secretion induced by atropine. The effects of cisplatin administration on sudomotor function were investigated in two groups of mice, one treated with high doses of cisplatin (10 mg/kg/week for 4 weeks) and another treated with low doses of cisplatin (5 mg/kg/week for 8 weeks). Cisplatin intoxication produced abnormal sudomotor responses indicative of denervation from cumulative doses of 10 mg/kg. The first abnormality found was a partial resistance of sweat glands to atropine, followed by a decrease in the sweat output per gland and finally a decline in the number of sweat glands activated by pilocarpine. These abnormalities in the sudomotor responses were more pronounced in mice treated with a high dose than in those with a lower dose regime.

Animals↗