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Biomedical subjects

I Rodríguez

Publications and source records attributed to I Rodríguez.

At least 19 recordsLinked to original sources
PubMed1999

Microchannel electrophoretic separation of biogenic amines by micellar electrokinetic chromatography.

Fast, efficient separation of most common biogenic amines was successfully performed on a glass microchip capillary electrophoresis device. The amines putrescine, histamine, tyramine, cadaverine, phenethylamine, tryptamine, spermidine and spermine were derivatized prior to fluorescence detection with fluorescein isothiocyanate. Separation was carried out using a channel length of 28 mm, a cross section of 50 x 8 microm, and a field strength of 600 V/cm. After optimization of buffer electrolyte conditions (120 mM boric acid, pH 9.4, modified with 40 mM SDS), fluorescein thiocarbamyl amine derivatives were successfully resolved. Analysis time was as short as 75 s. Determination of the biogenic amines was achieved in soy sauce samples.

Biogenic Amines↗
PubMed1999

Coexistence of primary hyperparathyroidism and thyroid disease.

Primary hyperparathyroidism (HPT) and thyroid disease are both relatively common diseases, which can coexist in the same patient. However, mere coincidence does not seem to be a satisfactory explanation for this association. Some factors like prior exposure to radiation may play a role in the association. The aim of this study was to determine the frequency of thyroid disease associated with HPT in 54 consecutive patients who underwent parathyroidectomy in our center from January 1990 to December 1997. Twenty-eight (52%) patients had thyroid disease associated to HPT. The patients had a mean age of 61+/-13 yr; they were predominantly postmenopausal women. Thyroid disease was detected preoperatively in 20 (71%) patients and during the surgical procedure in 8 (29%). Two patients had previous radiation exposure; one of them with papillary carcinoma of the thyroid. Two patients had hypothyroidism. UItrasonography was performed in the majority of patients in their preoperative evaluation. A multinodular goiter was seen to be the most frequent finding (76%). In addition to parathyroidectomy, 23 (82%) patients were also thyroidectomized. In conclusion, patients with HPT showed a high prevalence of thyroid disease, especially in postmenopausal women. Unsuspected thyroid lesions were found with sufficient frequency to warrant careful preoperative and intraoperative evaluation of both glands, in order to obviate reoperation. In experienced hands, combined surgery can be safely performed. Cervical ultrasonography is useful in the preoperative detection of nodular thyroid disease in these patients.

Adolescent↗
PubMed1998

Use of the C3H/He Lyme disease mouse model for the recovery of a Spanish isolate of Borrelia garinii from erythema migrans lesions.

A skin biopsy from a patient with erythema migrans was inoculated into C3H/He mice and into culture medium. A Borrelia garinii strain named Rio1 was isolated from both a direct BSK medium culture and a mouse ear-punch biopsy culture. Inoculating human tissue into mice produced a disease resulting in severe inflammation of the left tibio-tarsal joint, development of perivascular infiltrates as seen in ear-punch biopsies and the spread of spirochaetes along the skin, far from the inoculation site. The isolation of this strain confirms the circulation of this Borrelia species in Spain as a human pathogen, as well as its arthrogenicity in an animal model. The method used to recover strain Rio1 from human tissue is described as rapid and sensitive compared to direct inoculation of tissue into BSK medium.

Animals↗
PubMed1998

Valproic acid clearance in children with epilepsy.

OBJECTIVE: To evaluate population pharmacokinetics and the relationship between plasma concentration and daily dose of valproic acid (VPA) in a homogeneous group of children with epilepsy. METHODS: One hundred and fifty-one steady-state VPA plasma level measurements were made in 62 children aged 8 months to 6 years who were receiving VPA monotherapy. RESULTS: The level:dose ratio increased with age, its mean value was 1.7 in children aged under 2 years, 2.1 in children aged 2.4 years and 3.3 in children aged 4.6 years. Weight-adjusted values of VPA clearance (Cl) decreased with increasing age. The Cl values in these three age groups were 24.5+/-12.4 ml/kg/h, 19.9+/-6.1 ml/kg/h and 12.7+/-3.0 ml/kg/h, respectively. The relationship between VPA clearance and age was: Cl (ml/kg/h)=47.6 x age (months)(-0.29), (r=-0.87). This equation allows the estimation of VPA plasma clearance on the basis of the child's age, within the range 8-72 months. Therefore, it can be used to establish the initial maintenance paediatric dose of VPA in monotherapy. CONCLUSION: The relationship between clearance and age should be useful when establishing a pharmacokinetic programme for VPA monotherapy in children.

Age Factors↗
PubMed1998

[Survey of sexually transmitted diseases in the region of Rio Cuarto].

Sexually transmitted diseases (STD) are acquired mainly through sexual intercourse, being one of the most frequent groups of infectious diseases worldwide and consequently an important public health problem. The aim of this paper was to determine the current state of STD and to compare different diagnostic methods in the population studied. A total of 1060 samples from vaginal flows, endocervical material and urethral discharge were studied during 3 years. Of the total samples, 583 were positive, 493 in women and 90 in men. Microorganisms found in women were: Gardnerella vaginalis (39.3%), Candida albicans (21.1%), Trichomonas vaginalis (17.3%), Candida trachomatis (11.3%), Neisseria gonorrhoeae (3.2%): Mycoplasma hominis and Ureaplasma urelyticum (6.5%) and Treponema pallidum (1.4%), the associations found were, Gardnerella vaginalis with Trichomonas vaginalis 5.5%; Gardnerella vaginalis with Candida albicans 4.9%; Trichomonas vaginalis with Neisseria gonorrhoeae (2.2%) and Gardnerella vaginalis with Chlamydia trachomatis (1.9%). In men, gonococcal urethritis (UG) represented 37.7% non UG 55.6% and Treponema pallidum 6.7%. These results indicate a decrease in sifilis and in UG when compared to previous studies showing that gonococcal cervicitis had also decreased. We found an important increase in the prevalence of urethritis and non gonococcal cervicitis in agreement with world statistics which consider these diseases as the most common venereal ones. It is necessary to increase the search for Chlamydia trachomatis in pregnant women due to vertical transmission. It should be noted that, in spite of certain fluctuations, the incidence of the STD in our area is still unacceptably high.

Adolescent↗
PubMed1997

Evaluation of two solid-phase extraction procedures for the preconcentration of chlorophenols in drinking water.

Two off-line concentration procedures for the determination of sixteen chlorophenols in drinking water were developed. One involves acetylation of the samples and their subsequent preconcentration over graphitized carbon black cartridges. In the other, chlorophenols are derivatized following preconcentration over cross-linked styrene-divinylbenzene. The two proposed procedures are compared in terms of chlorophenol recoveries, throughput and breakthrough volume of the cartridges. The acetylated derivatives of chlorophenols are determined highly selectively at the concentration levels established by international legislation using gas chromatography in combination with microwave induced plasma atomic emission spectroscopy.

Chlorophenols↗
PubMed1997

Determination of phenolic pollutants in drinking water by capillary electrophoresis in the sample stacking mode.

A method for the determination of phenol, chlorophenols and nitrophenols at levels below those allowed by international legislation in water from the public supply is proposed. Ten of the compounds studied are included on the USA Environmental Protection Agency priority list of aquatic pollutants. Samples are concentrated off-line on cross-linked polystyrene and subsequently subjected to capillary electrophoresis using the sample stacking procedure to remove the matrix. The recoveries afforded by the off-line concentration process and the behaviour of the phenols in relation to sample stacking injection were examined.

Chlorophenols↗
PubMed1997

Speciation of organotin compounds in marine biomaterials after basic leaching in a non-focused microwave extractor equipped with pressurized vessels.

A rapid method for the speciation of butyl- and triphenyltin compounds in marine biotissues is described. A non-focused microwave extractor, operating at a power of 950 W and equipped with 12 pressurized vessels, was used to achieve fast sample leaching with tetramethylammonium hydroxide. The pH of the liquid extract was adjusted to 5. Organotins were ethylated with sodium tetraethylborate, extracted in isooctane and determined by means of a microwave-induced plasma atomic emission detector coupled to a gas chromatograph. The stability of butyl and phenyl compounds, exposed to the microwave energy, was studied as a function of the vessel temperature. The possibility of simultaneous carried-out extractions and the use of microwave to perform the ethylation and extraction of organotin compounds was also studied. The full procedure was validated with certified material NIES-11 and with real samples, by comparison with a classic leaching method using tetramethylammonium hydroxide without microwave.

Animals↗
PubMed1997

CYP2D6, NAT2 and CYP2E1 genetic polymorphisms in nonagenarians.

BACKGROUND: enzymatic polymorphisms affecting the metabolic disposition of xenobiotics may modulate the rate of activation or deactivation of carcinogens and other toxic environmental chemicals. Hence, these polymorphisms may influence the risk of suffering some types of cancer and other degenerative diseases that are incompatible with extreme longevity. AIMS: to establish the distribution of three well known enzymatic polymorphisms that affect the CYP2D6, NAT-2 and CYP2E1 genes and the activity of their enzymatic gene products, involved in the disposition of many xenobiotics, in a group of nonagenarians and in much younger controls. PATIENTS: the three genotypes were determined in 41 nonagenarians (10 males, mean age 92.2 years, range 90-98) free of known malignancies or neurodegenerative diseases. The control groups comprised 217 healthy volunteers (128 males, mean age 36.3 years; SD, 12.7) for the CYP2D6 and NAT2 genotypes and 137 (116 males, mean age 32 years; SD, 18.8) for the CYP2E1 genotype. METHODS: after extraction of DNA from white blood cells, polymerase chain reaction and restriction fragment polymorphism methods were used to identify the allelic variants of the three genotypes. RESULTS: we found no qualitative or quantitative difference in the mutations underlying the three genetic polymorphisms studied, nor in the expected enzymatic phenotypes. Instead, a close parallelism exists between advanced age and younger groups. CONCLUSION: longevity does not seem to be related to any special configuration of these three polymorphic traits. Comparisons with younger controls may be adequate when studying the distribution of these polymorphisms in diseases affecting old people. No genetically determined differences in the activation of drugs metabolized by these enzymes are to be expected in very old people.

Aged↗
PubMed1997

[Clinical and epidemiologic study of meningococcal meningitis in the health region of Santiago de Compostela (1990-1997)].

BACKGROUND: The aim of this study was to determine the clinico-epidemiologic characteristics of meningitis caused by Neisseria meningitidis. METHODS: A retrospective study was performed of the bacterial meningitis with LCR positive cultures for Neisseria meningitidis from January 1990 to 31 March, 1997. To calculate the rate of incidence data from the 1990 population census were used corresponding to a population of 465,786 inhabitants per year attended in our hospital. RESULTS: A growth was observed in the strains of N. meningitidis in 61 LCR, representing 30% of all positive LCRs. Thirty-three strains belonged to serogroup B (54%) and 28 of serogroup C (46%). Ninety-one point nine percent of the cases were found in patients under the age of 20. The annual rates of incidence ranged from 2.3 cases/100,000 inhabitants in 1990 to 3.4 cases/100,000 inhabitants in 1996 with a slight decrease between these two dates. In patients under the age of 15 years, the rates of incidence ranged from 12.3/100,000 in 1990 to 13.4 per 100,000 inhabitants in 1996. In the remaining years the rates decreased with a minimum of 2.2 cases/100,000 inhabitants. The incidence for N. meningitis serogroup C ranged from 0 to 0.9 cases/100,000 inhabitants between 1990 and 1995. In 1996 the rate increased up to 2.6 cases/100,000 inhabitants. The rate of mortality was 6.6% and sequelae 8.7%. Since 1995 strains with decreased sensitivity to penicillin have been isolated, with percentages ranging from 20% to 56.25%. All strains remained sensitive to third generation cephalosporins and rifampicin. CONCLUSIONS: Neisseria meningitidis remains the most frequent etiologic agent of acute bacterial meningitis. The increase in serogroup C strains and the ever more frequent appearance of strains with decreased resistance to penicillin are confirmed, as is the persistence of high levels of endemia in our medium.

Adolescent↗
PubMed1997

[Determination of insecticide resistance and its biochemical mechanisms in 2 strains of Culex quinquefasciatus from Santiago de Cuba].

It was analyzed the behavior of the resistance of 3 organophosphated insecticides (malathion, clorpirifos and methyl-pyrimifos), 3 pyrethroids (deltamethrin, lambda-cyhalothrin and cypermethrin), and 1 carbamate (propuxur) in populations of Culex quinquefasciatus from 2 municipalities of the province of Santiago de Cuba. The values of the resistance factor proved that there is resistance to malathion and clorpirifos. However, in spite of the existence of a high frequency of the mechanisms of elevated esterases and altered acetylcholinesterase no resistance to methylpymirifos, was observed which demonstrated that this insecticide is not affected by these mechanisms selected in our populations of Culex quinquefasciatus. There was resistence to deltamethrin, and lambda-cyhalothrin in Santiago de Cuba, whereas it was moderate to cypermethrin in Santiago and San Luis. Resistance to deltamethrin was also found in San Luis, but it was mild to lambda-cyhalothrin. The results obtained from the use of the synergists S,S,S tributyl phosphotritiade (DBF) and piperonyl butoxide (PB) indicated that the mechanisms of resistance of unspecific esterases and oxidases of multiple function are involved in the resistance to pyrethroids in both strains from Santiago de Cuba and San Luis. It was determined by the biochemical tests that there existed a high frequency of the mechanisms of esterases and altered acetylcholinesterase. The results of the polyacrylamide gel electrophoresis (PAGE) showed that esterase B1 appears more frequently associated with esterases A6 and B6. It was inferred that this association could be connected with the resistance to pyrethroids.

Acetylcholinesterase↗
PubMed1996

Determination of chlorophenols in drinking water with high resolution gas chromatography-tandem mass spectrometry.

A new method for the determination of sub-ppb levels of chlorophenols in drinking water by use of GC-MS-MS is proposed. Monitoring of these analytes for assurance of compliance with legally allowed limits can readily be accomplished by extraction as acetylated chlorophenols from low sample volumes (10 ml). Much lower detection limits can be achieved by preconcentrating 11 of sample using graphitized carbon cartridges for solid extraction. Appropriate selection of parent ions and fragmentation conditions ensures not only a high sensitivity, but also clean product ion spectra that allow positive identification of every species considered (polychlorophenol isomers included).

Calibration↗
PubMed1996

A new Borrelia species isolated from patients with relapsing fever in Spain.

BACKGROUND: Lyme disease and tick-borne relapsing fever are worldwide systemic borrelioses caused by several Borrelia species transmitted by hard ticks (family Ixodidae) and soft ticks (family Argasidae), respectively. A previous seroepidemiological study of Lyme borreliosis showed several serologically reactive patients with clinically atypical presentations, and this discovery led to the hypothesis that some of the cases of Lyme borreliosis had been caused by another borrelia organism. METHODS: Blood from patients in southern Spain who had suspected Lyme disease or relapsing-fever borreliosis was cultured before treatment began. Isolates of Borrelia spp were inoculated into several strains of mice of different ages. The 16S rRNA and flagellin in genes of Borrelia spp were sequenced by PCR and assessed by phylogenetic analyses. FINDINGS: We isolated a species of Borrelia from three patients with relapsing fever and from Ornithodorus spp ticks in southern Spain. This organism (refractory to in-vitro cultivation) caused a relapsing spirochaetaemia with multiple organ involvement in laboratory mice that recreated the human disease. Phylogenetic analysis showed that this organism is a previously unrecognised species. INTERPRETATION: We have discovered a new borrelia pathogen that is closely related to the other tick-borne agents of relapsing fever in Europe and Africa, and which causes a relapsing systemic disease with serological similarities to Lyme borreliosis.

Animals↗
PubMed1996

Identification of fatty acids in edible wild plants by gas chromatography.

The total lipidic content and the distribution of fatty acids in twenty edible wild plants in S.E. Spain was determined by GC. The lipidic content was higher than usual in the common vegetables. The high ratio of the omega 3 series of unsaturated fatty acids relative to the omega 6 series demonstrates the good nutritional qualities of these plants.

Arachidonic Acid↗
PubMed1996

Disposition of fluvoxamine in humans is determined by the polymorphic CYP2D6 and also by the CYP1A2 activity.

BACKGROUND: Fluvoxamine is a selective serotonin reuptake inhibitor used widely in the treatment of depression and other psychiatric diseases, but little is known about the specific isozymes involved in its metabolism. This study investigated the relationship between fluvoxamine disposition and the polymorphic CYP2D6 and the polycyclic aromatic hydrocarbon (as contained in cigarette smoke) inducible CYP1A2. METHODS: Fluvoxamine (50 mg orally) was given to 10 extensive metabolizers and four poor metabolizers of debrisoquin, and concentrations were assessed in plasma by high performance liquid chromatography. Five of the extensive metabolizers and one of the poor metabolizers were smokers of more than 10 cigarettes per day. The CYP1A2 activity was determined by means of a urinary caffeine test. RESULTS: Compared with nonsmoking extensive metabolizers, nonsmoking poor metabolizers had a statistically significant (p = 0.02, Mann-Whitney U test) about twofold higher maximum plasma concentration, longer half-life, and fivefold lower oral clearance of fluvoxamine. The oral clearance of fluvoxamine correlated to the CYP1A2 index in the 14 subjects (rs = 0.58; p < 0.05; Spearman rank correlation). CONCLUSION: The disposition of fluvoxamine in humans is associated with the polymorphic CYP2D6 activity, but CYP1A2 also seems to be involved.

Adrenergic Agents↗
PubMed1996

Effects of physical exercise on some parameters of bone metabolism in postmenopausal women.

This study was performed on 19 postmenopausal female volunteers in a period of five months of moderate physical exercise in order to examine beneficial changes in muscle strength and flexibility as well as changes in sex hormone binding globulin (SHBG) and other parameters related to bone metabolism. While SHBG decreased significantly (from 56.0 +/- 20.0 to 43.9 +/- 16.1 nM, P = 0.009) phosphorus and urea increased (from 2.8 +/- 0.4 to 4.0 +/- 0.5 mg/dl, P = 0.00006 and from 32.1 +/- 9.4 to 42.3 +/- 11.0 mg/dl, P = 0.03, respectively). These changes were accompanied by significant increases in muscle strength and flexibility. Other parameters such as alkaline phosphatase and calcium did not change significantly during the study. Plasma levels of SHBG were negatively correlated with phosphorus. As higher SHBG has been related to increased bone loss in older women, we conclude that moderate physical activity is an effective means to preserve bone loss in postmenopausal women.

Alkaline Phosphatase↗
PubMed1995

Cis-regulation of achaete and scute: shared enhancer-like elements drive their coexpression in proneural clusters of the imaginal discs.

The pattern of bristles and other sensory organs on the adult cuticle of Drosophila is prefigured in the imaginal discs by the pattern of expression of the proneural achaete (ac) and scute (sc) genes, two members of the ac-sc complex (AS-C). These genes are simultaneously expressed by groups of cells (the proneural clusters) located at constant positions in discs. Their products (transcription factors of the basic-helix-loop-helix family) allow cells to become sensory organ mother cells (SMCs), a fate normally realized by only one or a few cells per cluster. Here we show that the highly complex pattern of proneural clusters is constructed piecemeal, by the action on ac and sc of site-specific, enhancer-like elements distributed along most of the AS-C (approximately 90 kb). Fragments of AS-C DNA containing these enhancers drive reporter lacZ genes in only one or a few proneural clusters. This expression is independent of the ac and sc endogenous genes, indicating that the enhancers respond to local combinations of factors (prepattern). We show further that the cross-activation between ac and sc, discovered by means of transgenes containing either ac or sc promoter fragments linked to lacZ and thought to explain the almost identical patterns of ac and sc expression, does not occur detectably between the endogenous ac and sc genes in most proneural clusters. Our data indicate that coexpression is accomplished by activation of both ac and sc by the same set of position-specific enhancers.

Animals↗