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Biomedical subjects

A Arias

Publications and source records attributed to A Arias.

At least 19 recordsLinked to original sources
PubMed2002

Antimicrobial studies on three species of Hypericum from the Canary Islands.

The antimicrobial activity of several extracts and fractions of the aerial parts of Hypericum canariense, Hypericum glandulosum and Hypericum grandifolium was investigated using the disc diffusion and broth microdilution methods against twelve reference microorganisms (eight bacterial and four fungal strains). The methanol extract and chloroform fraction of H. canariense, as well as the methanol extracts, butanol and chloroform fractions of both H. glandulosum and H. grandifolium exhibited a good antibacterial activity against four Gram-positive bacteria (Bacillus cereus var. mycoides, Micrococcus luteus, Staphylococcus aureus and Staphylococcus epidermidis) and the Gram-negative bacterium Bordetella bronchiseptica with the diameters of growth inhibition area in the range 10-25 mm and MICs values between 0.03 and 0.29 mg/ml. Neither the infusions and aqueous fractions of the species studied nor the butanol fraction of H. canariense showed any antibacterial activity against the tested microorganisms. Amongst the active extracts, the minimum inhibitory concentration (MIC) determination showed that the H. canariense chloroform fraction was the most active against M. luteus, S. aureus and S. epidermidis. No antifungal activity was seen with any of the extracts or fractions tested. The results of this study support the use of these species in Canarian traditional medicine to treat skin infections.

Anti-Bacterial Agents↗
PubMed2002

Comparison of Albicans ID2 agar plate with the germ tube for presumptive identification of Candida albicans.

Albicans ID2 (bioMérieux, France) is a commercially available chromogenic medium that allows rapid and specific macroscopic identification of Candida albicans and facilitates the differentiation of species in mixed cultures. We compared it with the standard method for the identification of yeast species, the germ tube test (GT). This study involved 423 clinical isolates, including 163 C. albicans and 260 non-albicans yeasts. Sensitivity of Albicans ID2 agar plates regarding the identification of C. albicans were 98.2% after 48 h of incubation and specificity of 96.6%. This method using rapid enzymatic method shows the same similar sensitivity than the GT test The false negative rate (1.8%) for the GT test is consistent with that previously reported. None tests discriminated between C. albicans and C. dubliniensis isolates.

Agar↗
PubMed2001

[Concentration of thyrotropic hormone and free thyroxin in children with Down's syndrome].

The incidence of hypothyroidism is higher among children with Down syndrome than among children in the general population. The frequency of hypothyroidism is higher in the areas of endemic goiter than in other areas. The aim of this paper was to study the concentrations of TSH and FT4 in children with Down syndrome residents of Mérida, a region of Venezuelan Andes. At the Centro de Estudio y Prevención del Retardo Mental y Alteraciones en el Desarrollo (CEPREMAD), the thyroid function was studied in 48 children (1 month to 6 years old), who had Down syndrome, and in 123 healthy children of similar ages. All the children were referred to the Center for thyroid function evaluation. Two (4.2%) of the 48 children with Down syndrome had congenital hypothyroidism and 22 (45.8%) had subclinical hypothyroidism (high concentration of thyrotropin-TSH). Among the control children, only 14% had elevated levels of TSH. There were no differences in relation to the gender. In conclusion in children with Down syndrome, the frequency of high concentrations of TSH was three times higher than the frequency among the healthy children. The frequency of hypothyroidism was similar to that found in areas without endemic goiter.

Biomarkers↗
PubMed2000

Memory in viral quasispecies.

Biological adaptive systems share some common features: variation among their constituent elements and continuity of core information. Some of them, such as the immune system, are endowed with memory of past events. In this study we provide direct evidence that evolving viral quasispecies possess a molecular memory in the form of minority components that populate their mutant spectra. The experiments have involved foot-and-mouth disease virus populations with known evolutionary histories. The composition and behavior of the viral population in response to a selective constraint were influenced by past evolutionary history in a way that could not be predicted from examination of consensus nucleotide sequences of the viral populations. The molecular memory of the viral quasispecies influenced both the nature and the intensity of the response of the virus to a selective constraint.

Animals↗
PubMed2000

Influence of human wet cerumen on the growth of common and pathogenic bacteria of the ear.

The available data on the effect of human wet cerumen on bacterial growth are not conclusive. Nevertheless it is widely accepted that cerumen has a bactericidal effect. In this study the activity of human wet cerumen on bacterial growth was assessed by applying cerumen suspensions to bacterial cultures. Bacterial counts were performed before and after application of cerumen suspensions. A total of 383 assays was carried out with 73 pools of cerumen that were tested against cultures of Staphylococcus aureus, Staphylococcus epidermidis, Corynebacterium spp., Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa and Serratia marcescens. An increase in growth occurred much more frequently than a decrease in growth in almost every microrganism tested, with the mean increase percentage being much higher than the mean decrease percentage, except in the case of S. aureus. The largest average growth increase was obtained with E. coli. The largest average decrease in bacterial growth was recorded with S. marcescens. Our study does not support the conception of a decrease in bacterial growth produced by humen wet cerumen. In vitro, the most observable effect was in fact an increase in microbial growth.

Adolescent↗
PubMed1999

Glycogen depletion rather than glucose 6-P increments controls early glycogen recovery in human cultured muscle.

In glycogen-containing muscle, glycogenesis appears to be controlled by glucose 6-phosphate (6-P) provision, but after glycogen depletion, an autoinhibitory control of glycogen could be a determinant. We analyzed in cultured human muscle the contribution of glycogen depletion versus glucose 6-P in the control of glycogen recovery. Acute deglycogenation was achieved by engineering cells to overexpress glycogen phosphorylase (GP). Cells treated with AdCMV-MGP adenovirus to express 10 times higher active GP showed unaltered glycogen relative to controls at 25 mM glucose, but responded to 6-h glucose deprivation with more extensive glycogen depletion. Glycogen synthase (GS) activity ratio was double in glucose-deprived AdCMV-MGP cells compared with controls, despite identical glucose 6-P. The GS activation peak (30 min) induced by glucose reincubation dose dependently correlated with glucose 6-P concentration, which reached similar steady-state levels in both cell types. GS activation was significantly blunted in AdCMV-MGP cells, whereas it strongly correlated, with an inverse relationship, with glycogen content. An initial (0-1 h) rapid insulin-independent glycogen resynthesis was observed only in AdCMV-MGP cells, which progressed up to glycogen levels approximately 150 micrograms glucose/mg protein; control cells, which did not deplete glycogen below this concentration, showed a 1-h lag time for recovery. In summary, acute deglycogenation, as achieved by GP overexpression, caused the activation of GS, which inversely correlated with glycogen replenishment independent of glucose 6-P. During glycogen recovery, the activation promoted by acute deglycogenation rendered GS effective for controlling glycogenesis, whereas the transient activation of GS induced by the glucose 6-P rise had no impact on the resynthesis rate. We conclude that the early insulin-independent glycogen resynthesis is dependent on the activation of GS due to GP-mediated exhaustion of glycogen rather than glucose 6-P provision.

Adenoviridae↗
PubMed1998

5-hydroxytryptamine1A receptor-mediated effects on adenylate cyclase and nitric oxide synthase activities in rat ventral prostate.

The rat ventral prostate possesses specific 5-hydroxytryptamine (5-HT1A) receptors coupled to adenylate cyclase. In vivo treatment of rats or in vitro preincubation of minced prostatic tissue with the 5-HT1A receptor agonist 8-hydroxy-2-(di-N-propylamino)-tetralin (8-OH-DPAT) in different experimental conditions shows the possibility of desensitisation mechanisms with switching from inhibitory to stimulatory pattern on adenylate cyclase activity. As in the majority of systems, we observed the inhibition of forskolin-stimulated adenylate cyclase activity as a functional correlate of 5-HT1A receptor activation. A similar feature occurred when the direct stimulation of the enzyme by the diterpene was replaced by a receptor-mediated activation with the neuropeptide vasoactive intestinal peptide. Furthermore, 8-OH-DPAT stimulated nitric oxide synthase (NOS) activity in a dose-dependent manner. Thus, serotonin appears to be able to act in the rat prostate gland through specific 5-HT1A receptors coupled to a complex system of signal transduction involving an inhibitory response of adenylate cyclase that can become stimulatory, as well as an enhancement of NOS activity.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1998

Study of common aerobic flora of human cerumen.

Cerumen is the product of the secretion of the sebaceous, ceruminous or apocrine glands together with cells exfoliated from the cornified stratum of the epithelium of the external auditory canal (EAC). In the present study we identified and quantified common flora of human cerumen. The mean count obtained was 10(6) microorganisms per ml of cerumen suspension. In 24 pools of cerumen (33.3 per cent) the isolates were monomicrobial, Staphylococcus epidermidis (12), Corynebacterium spp (10), Staphylococcus aureus (1) and Streptococcus saprophyticum (1). In 48 pools (66.6 per cent) we found polymicrobial isolates. The most commonly isolated bacteria in these polymicrobial isolates were S. epidermidis (35) and Corynebacterium spp. (43). It is noteworthy that there were isolates of Candida albicans in three cases; in one case of Pseudomonas stutzeri, in one case of Pseudomonas aeruginosa, and, on seven occasions, of S. aureus. The organisms isolated as common bacterial components of human cerumen in our experience were similar to those found by other authors. However, the mean count was much higher. This could be related to climatic conditions and to the length of time the cerumen had remained in the external auditory canal.

Adolescent↗
PubMed1997

Heme compounds as iron sources for nonpathogenic Rhizobium bacteria.

Many animal-pathogenic bacteria can use heme compounds as iron sources. Like these microorganisms, rhizobium strains interact with host organisms where heme compounds are available. Results presented in this paper indicate that the use of hemoglobin as an iron source is not restricted to animal-pathogenic microorganisms. We also demonstrate that heme, hemoglobin, and leghemoglobin can act as iron sources under iron-depleted conditions for Rhizobium meliloti 242. Analysis of iron acquisition mutant strains indicates that siderophore-, heme-, hemoglobin-, and leghemoglobin-mediated iron transport systems expressed by R. meliloti 242 share at least one component.

Animals↗
PubMed1997

Human mucopolysaccharidosis IIID: clinical, biochemical, morphological and immunohistochemical characteristics.

Mucopolysaccharidosis IIID (MPS IIID) is one of the rarest of the MPS-III syndromes. To date, the clinical manifestations of 10 patients have been reported, the deficient N-acetylglucosamine 6-sulfatase (G6S) enzyme has been purified, and the G6S gene has been cloned, sequenced and localized. However, morphological manifestations of this condition have not been reported and the pathogenesis of the severe neurological deficits remains an enigma. In this paper we describe and correlate the clinical, biochemical and pathological observations for 2 cases of MPS IIID. We used monoclonal antibodies against heparan sulfate (HS) and GM2-ganglioside, thin layer chromatography, mass spectrometry, and morphological techniques to demonstrate the nature and the distribution of the uncatabolized substrates. The majority of the cells in various tissues showed morphological changes expected with lysosomal storage of HS. The central nervous system (CNS) was most severely affected because of the secondary storage of GM2 and GM3 gangliosides in addition to the primary accumulation of HS. The extent as well as the distribution of the diverse storage materials varied within and among different neurons as observed in MPS-III A, B, and C syndromes. This study supports the hypothesis that the neurological dysfunction and neurodegeneration common to the Sanfilippo syndromes is, in part, due to the secondary metabolic perturbations induced by HS accumulation.

Adolescent↗
PubMed1996

[Evaluation of the system of direct purchase and distribution of urinary incontinence pads in primary care centers].

OBJECTIVE: To evaluate the impact of the pilot experience of direct purchase and distribution of incontinence diapers in primary health care centres of the Balearic Islands after 10 months of implementation. DESIGN: Comparison of diapers's public expenditures and use during 10 months of pilot experience (9/1/1994-6/30/1995: POSTC) to a same length period prior to pilot experience implementation (11/1/1993-8/31/1994: PREC). SETTING: Primary health care centres of the Balearic Islands (Spain). MEASUREMENTS AND RESULTS: Monthly mean of packages used in the PREC period was 3,246 packages/month, whereas monthly mean of packages used in POSTC period was 4,541 packages/month. It means an increase of 1,295 packages/month. The mean price per package got by public tender was 4,426 ptas., nearly half of mean unit price per package paid through the usual dispensing system of medical prescription (8,583 ptas.), thus producing a saving of 4,157 ptas. per package. A decreasing trend to the monthly mean of diapers use of the PREC period was observed in the last months of the experience. The monthly expenditures in diapers was 27,790 milions ptas. in the PREC period and 21,024 milions ptas. during the POSTC period. CONCLUSIONS: The expected increase in diapers use during the first year of implementation of this measure was 34.86%. Of this increase, 70.5% is attributed to development of stock in centres and the undergoing trend of diapers demand increase observed throughout the country.

Costs and Cost Analysis↗
PubMed1995

Socioeconomic factors and mortality in urban settings: the case of Barcelona, Spain.

STUDY OBJECTIVE: This study aimed to describe the relationship between health and socioeconomic indicators in the 38 neighbourhoods of the city of Barcelona, Spain. DESIGN: Mortality data for 1983-89 and socioeconomic data for each of the 38 neighbourhoods of Barcelona were used. Mortality indicators used were the comparative mortality figure, the ratio of potential years of life lost, and life expectancy at birth. Socioeconomic indicators were the percentage of unemployed, the percentage of illiteracy, monthly telephone usage, the average power and age of cars, and the average rateable value of buildings and of land. The statistical correlation between socioeconomic indicators and mortality indicators was studied by Spearman's rank correlation coefficient. SETTING: The 38 neighbourhoods of Barcelona, Spain. MEASUREMENTS AND MAIN RESULTS: The comparative mortality figure ranged from 87.41-152.43 and the ratio of potential years of life lost from 74.94-237.31 in both sexes. Both the absolute difference and the ratio of the value for the neighbourhood with lowest mortality and that with highest mortality were larger when premature mortality was examined. Life expectancy at birth ranged from 64.77-75.32 years in men and 75.04-81.51 in women. All correlations between mortality and socioeconomic indicators were high and statistically significant: the higher the unemployment and illiteracy levels and the older the cars, the greater the comparative mortality figure and ratio of potential years of life lost, and the lower the life expectancy (negative correlations). Conversely, the higher the telephone use, the more powerful the cars, and the greater the rateable value, the lower the mortality (negative correlations) and the greater the life expectancy. These correlations were greater in males than in females. The highest correlations were with illiteracy. CONCLUSIONS: This study has detected significant differences in mortality in a large town in the Mediterranean region of Europe.

Adolescent↗
PubMed1995

Determination of the susceptibility in vitro of 54 isolates of Mycobacterium fortuitum against three fluoroquinolones using two methods.

The in vitro susceptibility to ofloxacin, norfloxacin and ciprofloxacin or 54 Mycobacterium fortuitum isolates originating from clinical samples (7) of patients attending the Hospital Universitario de Canarias and Hospital del Tórax, and from environmental (47) sources, were determined. For this, two methods were used: dilution in agar with Middlebrook 7H10 Agar as a base medium culture, and broth microdilution, with Mueller-Hinton Broth without supplement. The different isolates under study revealed a uniform susceptibility by both methods against ciprofloxacin. 100% inhibition was obtained from a Minimum Inhibitory Concentration (MIC) of 0.25 microgram/ml, and 2 micrograms/ml of ciprofloxacin, for broth microdilution and dilution in agar, respectively. For ofloxacin and norfloxacin, all the isolates were inhibited at an MIC of 0.5 microgram/ml, by the broth microdilution method, which contrasted sharply with an MIC of 32 micrograms/ml, in the case of dilution in agar. In this study, we have observed the existence of differences in the in vitro susceptibility of the isolates of M. fortuitum against the three fluoroquinolones assayed, mainly for ofloxacin and norfloxacin, by both methods. We, therefore, consider it necessary to establish a standardized, reproducible assay method, for the study of sensitivity to atypical mycobacteria.

Anti-Infective Agents↗
PubMed1995

Etiology and therapy of chronic suppurative otitis.

Infectious diseases of the ear are important in adults due to their incidence and relapses. We carried out a study of aerobic microorganisms on 251 otic exudates from patients diagnosed as having chronic suppurative otitis media without cholesteatoma (119), chronic suppurative otitis media with cholesteatoma (85) and chronic external otitis (47). The microorganisms predominantly isolated were, Pseudomonas aeruginosa, Staphylococcus aureus and other Enterobacteriaceae. 86% of isolates were monomicrobial and 14% of isolates were polymicrobial. In these latter the predominantly isolated microorganisms were also P. aeruginosa, S. aureus, Corynebacterium spp. and Proteus mirabilis. P. aeruginosa was the most commonly isolated and showed the highest percentages of resistance against antimicrobial agents tested. P. aeruginosa was most susceptible to ciprofloxacin and imipenem, but much less susceptible to cefotaxime, moxalactam and trimethoprim-sulfamethoxazole. S. aureus was highly sensitive to amoxicillin/clavulanate, trimethoprim-sulfamethoxazole, rifampin and teichoplanin. 100% of the isolates were resistant to penicillin G and ampicillin.

Adolescent↗
PubMed1995

Determination of the in vitro susceptibility of 220 Mycobacterium fortuitum isolates to ten antimicrobial agents.

The authors investigated the in vitro susceptibility to antimicrobial agents of 220 Mycobacterium fortuitum isolates originating from clinical samples (14) of patients attending the Hospital Universitario de Canarias and Hospital del Tórax, and from environmental sources (206): 3 from sea water, 10 from the water supply and 193 from sewage. The Minimum Inhibitory Concentration (MIC) was calculated using the broth microdilution method with Mueller-Hinton Broth without supplement. Amikacin was the most efficacious antimicrobial agent against all the isolates of M. fortuitum with an MIC which was considerably lower than its critical concentration. The good results achieved with amikacin in vitro are confirmed by those obtained in vivo, with patients infected with M. fortuitum. No significant difference was found in the efficacy of amikacin and ofloxacin against all the isolates assayed.

Anti-Bacterial Agents↗
PubMed1995

[In vitro sensitivity of Mycobacterium chelonae strains to various antimicrobial agents].

The in vitro susceptibility of 32 Mycobacterium chelonae strains to 10 antimicrobial agents was determined. The sources of the different strains were: clinical samples from patients treated at the Hospital Universitario de Canarias and Hospital del Tórax (General and Chest facilities) and from environmental sources (water supply, sewage, swimming pools and the sea). The susceptibility tests were performed by a broth microdilution method (Mueller-Hinton Broth). The results showed amikacin as the most effective antimicrobial agent against M. chelonae isolates, then ofloxacin and cefoxitin. However no statistical difference was detected among them. The least effective was imipenem, followed by ciprofloxacin and norfloxacin.

Amikacin↗
PubMed1994

A health-sanitary evaluation of lacteal desserts for consumption in Santa Cruz de Tenerife.

The consumption of lacteal desserts in the province of Santa Cruz de Tenerife is notably high. However, there are no legal standards in Spain regarding microbiological quality. For this reason, we have decided that it would be of interest to carry out a health-sanitary study of these products, with the aim of discovering their microbial content. 330 samples of lacteal desserts on sale in the province of Santa Cruz de Tenerife have undergone analysis. They have been divided into three groups: cream caramel (egg and vanilla) (80), mousse (60) and the third group, known as "other desserts", which includes custard and the rest of lacteal desserts not included in the previous groupings (190). Neither E. coli, Salmonella spp., Shigella spp., nor Staphylococcus aureus have been detected in any of the samples analysed. In spite of the fact that the results obtained do not reflect high microbiological contamination, we consider it necessary to lay down legal standards, with reference values, for these lacteal products, which will guarantee good microbiological quality.

Bacteria, Aerobic↗