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Biomedical subjects

M A Hernández

Publications and source records attributed to M A Hernández.

At least 19 recordsLinked to original sources
PubMed2006

Phenolic glycosides from Exostema mexicanum leaves.

Phytochemical investigation of the leaves of Exostema mexicanum led to the isolation of two novel acylated flavonol glycosides 6, 7 and three glycosides 1-4 structurally belonging to the group of 4-phenylcoumarins. One of them, 5-O-beta-D-glucopyranosyl-4'-hydroxy-7-methoxy-4-phenylcoumarin (2), turned out to be new. Furthermore, the 4-phenylcoumarin aglycone 3'-hydroxy-4',5,7-trimethoxy-4-phenylcoumarin (5) was obtained. The in vitro cytotoxicity of 3-5 against the cell line ECV-304 was evaluated; the aglycone 5 was highly cytotoxic, whereas the glycosidic compounds 3 and 4 were inactive.

Antineoplastic Agents, Phytogenic↗
PubMed2005

Pattern of neuropsychological impairment in the early phase of relapsing-remitting multiple sclerosis.

To investigate the neuropsychological profile in the first few years post-onset of relapsing-remitting multiple sclerosis (MS) we carried out a comprehensive neuropsychological evaluation of 33 patients characterized by very short evolution of this disease, minimal levels of neurological disability and preserved general cognition. Thirty-three individually pair-matched controls were also evaluated. Patients performed as well as controls on many of the cognitive exploration measures. Nevertheless, the group of patients evinced a general slowness that affected motor execution and cognitive processing. Memory functions were characterized by preservation of working memory, retrieval or storage of information and a deficit at the acquisition phase in (verbal and visual) supraspan tasks. In addition, significant correlations were observed between some measures of information processing speed and memory. These results highlight the importance of studying cognitive deficits not only in the different subtypes of MS but also in different phases of the disease.

Adult↗
PubMed2004

Drug utilisation in outpatient children. A comparison among Tenerife, Valencia, and Barcelona (Spain), Toulouse (France), Sofia (Bulgaria), Bratislava (Slovakia) and Smolensk (Russia).

INTRODUCTION: Scarce information about comparative diagnostic and therapeutic patterns in paediatric outpatients of different countries is found in the literature. OBJECTIVE: To describe the similarities and differences observed in diagnosis and therapeutic patterns of paediatric patients of seven locations in different countries. DESIGN: Cross-sectional, prospective, international comparative, descriptive study. PATIENTS AND METHODS: A randomly selected sample of 12,264 paediatric outpatients seen in consultation rooms of urban and rural areas and attended by paediatricians or general practitioners of the participating locations. Data on patient demographic information, diagnosis and pharmacological treatment were collected using pre-designed forms. Diagnoses were coded using the ICD-9 and drugs according to the ATC classification. RESULTS: Among the ten most common diagnoses, upper respiratory tract infections are in the first position in all locations; asthma prevalence is highest in Tenerife (8.4%). Tonsillitis, otitis, bronchitis and dermatological affections are the most common diagnoses in all locations. Pneumonia is only reported in Sofia (3.8%) and Smolensk (2.3%). The average number of drugs prescribed per child varied from 1.3 in Barcelona to 2.9 in Smolensk. There are no great differences in the profile of pharmacological groups prescribed, but a considerable range of variations in antibiotic therapy is observed: prescription of cephalosporins is low in Smolensk (0.7%) and higher in the other locations, from 16.5% (Bratislava) to 28% (Tenerife). Macrolides prescriptions range from 12.6% (Toulouse) to 24.7% (Smolensk), except in Sofia where they drop to 5.6%. Trimethoprim and its combinations are used in Smolensk (23.3%), Sofia (11.8%) and Bratislava (8.7%). Check-up consultations are not recorded in Smolensk and Bratislava, whereas in Toulouse these visits account for 16.2% of all consultations and in the other locations the percentage varies from 6.1% (Tenerife) to 1.9% (Sofia). Homeopathic treatments are registered only in Toulouse. CONCLUSION: Except in asthma prevalence, there are no great differences in diagnostic maps among locations. Significant variations in the number of drugs prescribed per child and antibiotic therapies are observed. Areas for improvement have been identified.

Bulgaria↗
PubMed2004

DMSA study performed during febrile urinary tract infection: a predictor of patient outcome?

Technetium-99m dimercaptosuccinic acid (DMSA) study has been advocated as a method for the assessment of renal sequelae after acute febrile urinary tract infection (UTI). However, it is not known whether DMSA scintigraphy performed during acute UTI has any prognostic value for outcome assessment. The objective of this study was to evaluate the usefulness of DMSA scintigraphy performed during UTI as a predictor of patient outcome, to identify children at risk of events [vesico-ureteral reflux (VUR) or recurrent UTI] that may lead to the development of progressive renal damage. One hundred and fifty-two children (including 78 girls) with a mean age of 20 months (range 1 month to 12 years) with first febrile UTI were evaluated by DMSA scintigraphy during acute UTI. After acute UTI, children were explored by voiding cysto-urethrography. Children who presented an abnormal DMSA study, or a normal DMSA study but VUR or recurrent UTI, underwent a DMSA control study 6 months after UTI. Children with VUR were followed up by direct radionuclide cystography. DMSA scintigraphy performed during acute UTI was normal in 112 children (74%). In 95 of these children, follow-up DMSA scintigraphy was not performed owing to a good clinical outcome. In the remaining 17 children, follow-up scintigraphy was normal. Forty children (26%) presented abnormal DMSA study during acute UTI. Twenty-five of them presented a normal follow-up DMSA, and 15 presented cortical lesions. Children with abnormal DMSA had a higher frequency of VUR than children with normal DMSA (48% vs 12%). It is concluded that children with normal DMSA during acute UTI have a low risk of renal damage. Children with normal follow-up DMSA and low-grade VUR have more frequent spontaneous resolution of VUR.

Anti-Infective Agents, Urinary↗
PubMed2004

Pharmacological treatment of acute otitis media in children. A comparison among seven locations: Tenerife, Barcelona and Valencia (Spain), Toulouse (France), Smolensk (Russia), Bratislava (Slovakia) and Sofia (Bulgaria).

OBJECTIVE: To describe patterns observed in the treatment of acute otitis media (AOM) in several locations of five countries. PATIENTS AND METHODS: Cross-sectional, descriptive study. Random sample of 12,264 paediatric outpatients seen by paediatricians or general practitioners (GPs). Data on patient demographics, diagnoses and treatment were collected. Diagnoses were coded by ICD-9 and drugs by ATC classification. Patients diagnosed with AOM (ICD-9 codes: 381 and 382) were selected for analysis. RESULTS: Cases of AOM (873) accounted for 7.1% of the sample. There is a clear variation in the percentage of children diagnosed with AOM and treated with antibiotics in the different locations, antibiotic prescriptions being higher in Barcelona (93% of children), and lowest in Smolensk (56.4 % of children were treated without antibiotics). The antibiotics used varied widely: ampicillin use is almost limited to Smolensk (26.7%) and Bratislava (13.8%), whereas amoxicillin plus clavulanic acid is the choice in Toulouse (33.8%), Valencia (30.2%) and Barcelona (28.9%), and cephalosporins are more frequently prescribed in Tenerife (51.7%). Finally, macrolides are used in Barcelona (18.3%), Valencia (17.5%) and Tenerife (13.6%), but not prescribed in Toulouse or Sofia. Prescriptions of anti-inflammatory drugs were only relevant in Valencia (31.7%), Tenerife (27.2%) and Toulouse (17.4%) and of otological preparations in Sofia, where almost each child received ear drops (91.9%). Nasal preparations are commonly used only in Sofia (41.9%), Bratislava (65.5%) and Smolensk (68.6%). CONCLUSION: Despite the general agreement of most guidelines, wide differences in the treatment of uncomplicated AOM in children are observed. Non-antibiotic therapy for AOM and the use of first-choice antibiotics should be more actively encouraged in the primary care centres. Studies to measure prevailing rates of antibiotic resistance in these populations are needed.

Acute Disease↗
PubMed2004

Effect of cervical spinal cord stimulation on regional blood flow and oxygenation in advanced head and neck tumours.

BACKGROUND: Tumour ischaemia leads to decreased delivery of oxygen, chemotherapy and radiosensitisers. Hypoxia in head and neck (H&N) tumours is an important adverse prognostic factor. Spinal cord stimulation (SCS) is a well-established neurosurgical technique in the treatment of several ischaemic syndromes. This prospective study evaluated the effect of cervical-SCS on common carotid artery (CCA) blood flow and tumour oxygenation in patients with advanced H&N cancer. PATIENTS AND METHODS: Sixteen patients with advanced H&N tumours were enrolled. Cervical-SCS devices were inserted subcutaneously prior to commencement of scheduled chemoradiotherapy. Pre- and post-SCS measurements were as follows: (i) tumour oxygenation (mmHg) using polarographic probes; (ii) blood flow quantification (ml/min) and diastolic and systolic velocimetry (cm/s) in the CCA using colour Doppler. RESULTS: After SCS, median tumour oxygenation increased in two-thirds of patients (34%; P = 0.023), all patients had improved CCA blood flow (50%; P <0.001) and almost all patients showed an increased CCA diastolic velocity (26%; P = 0.003) and systolic velocity (20%; P = 0.011). CONCLUSIONS: Cervical-SCS increased tumour oxygenation and CCA blood flow, and could enhance the loco-regional delivery of oxygen, radiosensitising and chemotherapeutic drugs. Cervical-SCS as adjuvant in chemoradiotherapy of these tumours warrants further investigation.

Adult↗
PubMed2002

Quality of life in multiple sclerosis patients in Spain.

OBJECTIVE: The cross-sectional study evaluated the psychometric properties of the Functional Assessment of Multiple Sclerosis (FAMS) Spanish version and its use in measuring quality of life (QOL) of multiple sclerosis (MS) patients in Spain. METHODS: The FAMS is a factorially derived self-report scale designed to assess six primary aspects of QOL of patients with MS: Mobility, Symptoms, Emotional Well-Being, General Contentment, Thinking and Fatigue, and Family/Social Well-Being. Its Spanish translated version was used to assess QOL of 625 MS patients recruited in an outpatient clinic setting from 58 hospitals in Spain. Internal consistency of the Spanish FAMS was evaluated Multiple regression analyses were performed to identify significant predictors from demographic, clinical and treatment characteristics, and Kurtzke Expanded Disability Status Scale (EDSS) scores in predicting FAMS scale scores. RESULTS: Most of the patients are females (66%), and 74% were of the relapsing-remitting (RR) clinical subtype. Cronbach's alpha coefficients were high (range=0.78-0.96), indicating subscale homogeneity comparable to that of the original English version. Linear multivariate regression analyses revealed that the EDSS is a dominant variable in predicting all the FAMS subscales, especially mobility (R2=0.51) and the total scores. CONCLUSIONS: The Spanish FAMS is a psychometrically valid instrument that allows clinicians and clinical researchers the ability to measure the QOL concerns of MS patients in Spain.

Adult↗
PubMed2001

In vitro antiplasmodial activity of 4-phenylcoumarins from Exostema mexicanum.

The stem bark of Exostema mexicanum (Rubiaceae) is used in Latin American folk medicine as a quinine substitute for malaria treatment. Bioassay-guided fractionation of lipophilic and hydrophilic extracts from the stem bark and branches yielded two previously undescribed 4-phenylcoumarins: 4',8-dihydroxy-5,7-dimethoxy-4-phenylcoumarin (exomexin A) and 3',4'-dihydroxy-5,7,8-trimethoxy-4-phenylcoumarin (exomexin B). Together with five known derivatives the in vitro activities against a chloroquine-sensitive strain (poW) and a chloroquine-resistant strain (Dd2) of Plasmodium falciparum have been evaluated. The most lipophilic compound, 4',5,7,8-tetramethoxy-4-phenylcoumarin (O-methylexostemin) revealed the strongest antiplasmodial activity (IC50 values: 3.6 microg/ml [poW], 1.6 microg/ml [Dd2]).

Animals↗
PubMed1999

Microbial transformations of testosterone to 5alpha-dihydrotestosterone by two species of Penicillium: P. chrysogenum and P. crustosum.

Two species of Penicillium--P. chrysogenum and P. crustosum--were cultured in presence of [3H]testosterone as a substrate. Both species were shown to reduce the 4,5-double bond in testosterone to give dihydrotestosterone (DHT). The steroids produced were 5alpha-dihydrotestosterone, DHT, 3alpha-hydroxy-5beta-androstan-17-one, 3alpha-hydroy-5alpha-androstan-17-one, 4-androstene-3,17-dione, and 5alpha-androstane-3,17-dione. These products implicate the presence of the 5alpha-reductase, with maximal activity at pH 6 and 8, in both species of Penicillium. The presence of DHT in the growth medium and not in the mycelium suggests that DHT is excreted into the medium.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1998

Epilepsy, cerebral calcifications and clinical or subclinical coeliac disease. Course and follow up with gluten-free diet.

We have studied four patients (three male, one female, age range 15-25 years) with epilepsy, bilateral occipital calcifications and latent coeliac disease (CD). The epilepsy started at mean age 7 years, in three cases there were partial seizures and in one case generalized seizure. Three cases had symptoms suggesting malabsorptive syndrome during infancy and one case was diagnosed CD before the onset of seizures. In all cases serologic markers of CD were found, especially antiendomisium antibody, and intestinal biopsy indicated several grades of atrophy. The electroencephalograph (EEG) findings pointed to focal abnormalities in three patients and generalized abnormalities in one patient. In all cases computer tomography (CT) showed bilateral, almost symmetrical occipital calcifications in the cortical subcortical layers. The enhanced CT were unremarkable and magnetic resonance images (MRI) were normal. After diagnosis of CD, all patients followed a gluten-free diet and in three patients a significant reduction in seizure frequency was observed. CD should be ruled out in all cases of epilepsy, cerebral calcifications of unexplained origin and malabsorption syndrome in infancy.

Adolescent↗
PubMed1997

[Carboxyhemoglobin levels in relation with home heating].

To study carboxyhemoglobin levels (HbCO) associated with use of different types of home heating and to evaluate the usefulness of measuring hemoglobin oxygen saturation. Nonsmoking patients with chronic respiratory insufficiency who were initially prescribed home oxygen therapy were enrolled in the study. One hundred four patients were studied in winter and summer (when heating was not used). The control group consisted of 92 hospitalized patients not exposed to carbon monoxide. Of the 104 patients 74.1% were men. Mean age was 72.33 (range 17 to 97 years) and 57.9% lived in rural areas. Mean HbCO in the control group was 1.53 +/- 0.96% (p = 0.01). Among the 39% who burned slack coal for heat, the mean HbCO was 4.63 +/- 2.87%. The 23.7% with central heating had HbCO levels of 2.15 +/- 0.87% (p < 0.0001). Pulse oximetry (SpO2) estimated higher hemoglobin oxygen than direct measurement (SaO2): 87.12 +/- 6% and 83.3 +/- 8%, respectively (p < 0.001). High HbCO concentrations are related to chronic exposure to slack coal fumes. Pulse oximetry, as opposed to SaO2, overestimates hemoglobin oxygen saturation in such cases.

Adolescent↗
PubMed1994

Characterization of the acute phase serum protein response in pigs.

Acute inflammation was induced in pigs using a single subcutaneous turpentine injection. The acute phase serum protein response was analyzed using crossed immunoelectrophoresis and immunodiffusion. The concentration of C reactive protein and haptoglobin increases 5-7 times 48 h after the injection, whereas the concentration of an alpha 2-globulin, named pig major acute phase protein (pig-MAP), increases at least 15-fold. A molecular mass of 115 kDa for pig-MAP was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This protein did not crossreact with antisera to human hemopexin, ceruloplasmin, H-kininogen and complement factor C3. Albumin and alpha-lipoprotein were negative acute phase proteins because their concentration significantly decreased during inflammation. Finally, the concentration of alpha 1-acid glycoprotein, fetuin, alpha 1-protease inhibitor, transferrin and alpha 2-macroglobulins, as well as total proteins, did not change significantly during inflammation.

Acute-Phase Proteins↗
PubMed1990

Common antigenic determinants of the tubulin binding domains of the microtubule-associated proteins MAP-2 and tau.

The structural-functional aspects of the tubulin binding domain on the microtubule-associated protein MAP-2, and its relationship with the tubulin binding domain on tau, were studied using anti-idiotypic antibodies that react specifically with the epitope(s) on MAPs involved in their interaction with tubulin in addition to other tau and MAP-2 specific antibodies. Previous studies showed that MAP-2 and tau share common binding sites on tubulin defined by the peptide sequences alpha (430-441) and beta (422-434) of tubulin subunits. Furthermore, binding experiments revealed the existence of multiple sites for the interaction of the alpha- and beta-tubulin peptides with MAP-2 and tau. Most recent studies showed that the synthetic tau peptide Val187-Gly204 (VRSKIGSTENLKHQPGGG) from the repetitive sequence on tau defines a tubulin binding site on tau. Our present immunological studies using anti-idiotypic antibodies which interact with the synthetic tau peptide and antibodies against the Val187-Gly204 tau peptide indicate that MAP-2 and tau share common antigenic determinants at the level of their respective tubulin binding domains. These antigenic determinants appear to be present in the 35 kDa tubulin binding fragment of MAP-2 and in 18-20 kDa chymotryptic fragments containing the tubulin binding site(s) on MAP-2. These findings, along with structural information on these proteins, provide strong evidence in favor of the hypothesis that tubulin binding domains on MAP-2 and tau share similar structural features.

Amino Acid Sequence↗