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Biomedical subjects

M Blanco

Publications and source records attributed to M Blanco.

At least 91 records · Page 5Linked to original sources
PubMed1999

Development and validation of a method for the analysis of a pharmaceutical preparation by near-infrared diffuse reflectance spectroscopy.

A near-infrared (NIR) spectroscopic method based on the use of a fiber optical probe for the analysis of a commercially available pharmaceutical preparation is proposed. The analyte is identified by comparison with a second-derivative spectral library, using the correlation coefficient as the discriminating parameter. Once a sample has been positively identified, the active principle is quantified with partial least-squares (PLS) calibration. The proposed method was validated for use as a control method; to this end, the selectivity of the identification process, and the repeatability, intermediate precision, accuracy, linearity, and robustness of the active principle quantitation, were assessed.

Sensitivity and Specificity↗
PubMed1999

H. pylori-negative duodenal ulcer prevalence and causes in 774 patients.

The prevalence of H. pylori infection has been reported to be very high in duodenal ulcer (DU) disease, but the precise frequency and causes of H. pylori-negative DU are not well known. In some geographical regions, however, a relatively low prevalence of the infection has been described. Our aim was to study the frequency and causes of H. pylori-negative DU and to evaluate whether empirical H. pylori eradication therapy without confirmation of the infection is justified. In all 774 consecutive patients with an endoscopic diagnosis of DU were studied prospectively. Exclusion criteria were associated diseases and previous gastric surgery. The use of NSAIDs, antibiotics (during the last month), and proton pump inhibitors (during the last month) was evaluated by means of a specific questionnaire. At endoscopy, two biopsies from both antrum and corpus were obtained in all 774 patients for histologic study (H&E stain). One sample from the antrum for rapid urease test, one sample each from the antrum and corpus for culture, and two duodenal biopsies for histologic study were also obtained in the first 307 patients. A [13C] urea breath test was carried out in the remaining 467 patients. Patients were considered infected if any of the diagnostic tests were positive and noninfected when all tests performed were negative. Age (mean +/- SD) was 46+/-12 years, 70% were males. NSAID, antibiotic, and proton pump inhibitor use was described, respectively, in 8.9%, 5.8%, and 6.3% of the cases. H. pylori infection was demonstrated, overall, in 95.3% (95% CI: 93.6-96.6%) of the patients. H. pylori prevalence increased up to 99.1% (98.1-99.6%) if patients taking NSAIDs and/or antibiotics were excluded. Among the 36 H. pylori-negative patients, 20 (55%) were taking NSAIDs, 9 (25%) were taking antibiotics, and 1 (3%) both of them. Therefore, in only 6/774 patients (0.8%) could DU disease be considered truly "idiopathic." Differences were demonstrated between H. pylori-positive and -negative patients (univariate study; chi2) with regard to NSAID intake (7% vs 58%; P < 0.0001) and previous antibiotic use (5% vs 28%; P < 0.0001). In the multivariate analysis (logistic regression), NSAID use (OR: 0.06; CI: 0.03-0.13; P < 0.001) and antibiotic use (OR: 0.23; CI: 0.09-0.59; P < 0.01) were the only variables that correlated with H. pylori infection. The most important factors associated with H. pylori-negative DU are NSAIDs and prior antibiotic use, and if these agents are excluded, the prevalence of infection in our area is as high as 99%. Therefore, in DU patients not taking NSAIDs and living in areas where previous studies have shown the prevalence of the infection in DU disease to be very close to 100%, empirical H. pylori eradication therapy without confirmation of the infection may be justified.

Anti-Bacterial Agents↗
PubMed1999

Kinetic spectrophotometric determination of hydrocortisone acetate in a pharmaceutical preparation by use of partial least-squares regression.

A kinetic spectrophotometric method for the determination of hydrocortisone acetate based on its condensation with isonicotinic acid hydrazide is proposed. The method is applied to the determination of hydrocortisone acetate in a commercially available pharmaceutical preparation, presented as a pomade, that also contains another corticosteroid and additional active compounds. The operating procedure involves dissolving the pomade in chloroform and the addition of the reagent solution directly to the cuvette, in this way avoiding the previous extraction of analytes from the insoluble pomade matrix required by the alternative HPLC procedure. Calibration is performed by partial least-squares regression, using absorbance or first derivative spectra values recorded each minute during the first 30 min of reaction. Use of first derivative spectra overcomes possible scattered light problems produced by excipients precipitating, and produced slightly better results than absorbance data. The relative standard deviation obtained for 11 replicates analysed on different days was approx. 1.5%. The proposed method improves both accuracy and precision of the classical initial rate method and the precision of the HPLC procedure.

Hydrocortisone↗
PubMed1999

Development and validation of methods for the determination of miokamycin in various pharmaceutical preparations by use of near infrared reflectance spectroscopy.

New methods for the determination of the nominal content of miokamycin in three commercial pharmaceutical preparations available in many different forms are proposed. Solid samples, grinding of which is the sole pretreatment required, are analysed by near infrared (NIR) spectroscopy, using a fibre-optic probe. The active principle is quantified by partial least-squares regression (PLSR). The three proposed methods were validated with a view to their use as control methods; the selectivity of the method, and the repeatability, intermediate precision, accuracy, linearity and robustness of each PLSR calibration model used were determined. The relative standard error of prediction (RSEP) was < 1.5% and the validation results testify to the suitability of the proposed methods.

Anti-Bacterial Agents↗
PubMed1999

Joint replacement for a spontaneously ankylosed hip in a haemophilic patient.

A cemented Charnley total hip prosthesis was implanted in a 48-year-old man with mild haemophilia (factor VIII 4 IU dL-1) in his right spontaneously ankylosed hip. At the time of surgery he was anti-HCV positive, anti-HIV negative, and no circulating inhibitors were encountered. The indication for surgery was long-lasting intractable low back and ipsilateral knee pain. At 4-month follow-up, relief of pain was achieved as well as correction of limb-length discrepancy, with a good result according to the Mayo Clinic hip score. Doses of 50 IU kg-1 body weight of recombinant factor VIII (Recombinate; Baxter, Glendale, California, USA) was used during the 2 weeks of admittance to the hospital. The dosage was adjusted according to the recoveries of factor VIII, with an overall factor consumption of 68 000 IU. As far as we know this is the first case reported in the literature of a person with haemophilia in whom a spontaneous hip ankylosis has been satisfactorily converted in a total hip arthroplasty with a short-term follow-up. However, a much longer follow-up is still needed to ascertain the efficacy of this surgical procedure in haemophilia.

Adult↗
PubMed1999

Neurologic complications of type I aortic dissection.

BACKGROUND: Aortic dissection (AoD) is characterized by a transverse intimal tear that in most cases occurs in the right lateral wall of the ascending aorta. Neurological deficit is seen as an initial manifestation in about 20% of patients (8%-33%). OBJECTIVES: To analyze the frequency of these complications and the underlying pathogenic mechanisms. METHODS: Retrospective review of the neurologic complications of patients with type I AoD who underwent surgical treatment between January 1988/April 1996. RESULTS: We report 24 patients. Nine (37.7%) developed neurologic symptoms which we have classified as follows: Hypoxic encephalopathy, 5 (55.5%); ischemic stroke, 2 (22.2%); ischemic neuropathy, 2 (22.2%) and spinal cord ischemia, 1 (11.1%). One is included in both first and third group. CONCLUSIONS: Neurologic complications are frequent in type I AoD, mainly focal or global cerebral ischemia. The former could be due to advancement of the false channel towards the aortic arch vessels and the latter to global central nervous system hypoperfusion.

Adult↗
PubMed1999

vig-1, a new fish gene induced by the rhabdovirus glycoprotein, has a virus-induced homologue in humans and shares conserved motifs with the MoaA family.

We used mRNA differential display methodology to analyze the shift of transcription profile induced by the fish rhabdovirus, viral hemorrhagic septicemia virus (VHSV), in rainbow trout leukocytes. We identified and characterized a new gene which is directly induced by VHSV. This VHSV-induced gene (vig-1) encodes a 348-amino-acid protein. vig-1 is highly expressed during the experimental disease in lymphoid organs of the infected fish. Intramuscular injection of a plasmid vector expressing the viral glycoprotein results in vig-1 expression, showing that the external virus protein is sufficient for the induction. vig-1 expression is also obtained by a rainbow trout interferon-like factor, indicating that vig-1 can be induced through different pathways. Moreover, vig-1 is homologous to a recently described human cytomegalovirus-induced gene. Accordingly, vig-1 activation may represent a new virus-induced activation pathway highly conserved in vertebrates. The deduced amino acid sequence of vig-1 is significantly related to sequences required for the biosynthesis of metal cofactors. This suggests that the function of vig-1 may be involved in the nonspecific virus-induced synthesis of enzymatic cofactors of the nitric oxide pathway.

Amino Acid Sequence↗
PubMed1999

Pancreas ultrastructural alterations in mice inoculated with Tityus discrepans (Buthidae) venom.

The symptoms of scorpionic envenomation in mice appear almost immediately after intraperitoneal injection and are manifested by great agitation, hair bristling, accelerated respiration, salivation and lacrimation, vomits and diarrhoea. In this work we intend to correlate those clinical manifestations appearing in response to the toxic aggression by Tityus discrepans venom, to the cellular or subcellular alterations produced in the mouse pancreas, probably similar to those damages found in envenomed humans. To evaluate pancreas subcellular response to Tityus discrepans venom, male C57/Bl adult mice were randomised into two groups: envenomed were intraperitoneally injected (hypochondrial left region) at a dose of 5 mg/Kg weight and controls received saline solution. Samples after preparation were studied in a Hitachi-300 transmission electron microscope. The most relevant ultrastructural changes in pancreatic tissues were an increase in the nuclear heterochromatin, with a corresponding decrease of euchromatin. In the cytoplasm, rough endoplasmic reticulum exhibited zones of oedema, losing its organised aspect. The secretion granules presented smaller electron density and variability in dimensions. At higher magnification a nucleus with picnotic appearance, with indentation of its perinuclear cistern was observed. There was a mitochondrial degeneration, with destruction of the mitochondrial matrix and autophagic vacuoles in its interior. At 48 h the lesions became intensified, with an evident increase in the intercellular spaces.

Animals↗
PubMed1998

Mutation analysis of Gaucher disease patients from Argentina: high prevalence of the RecNciI mutation.

Gaucher disease (GD) is caused by a deficiency of beta-glucocerebrosidase activity mainly due to mutations in the gene coding for the enzyme. More than 100 mutations have been identified to date and their frequencies have been established in several populations, including Ashkenazi Jews, among whom the disease is particularly prevalent. In order to study the molecular pathology of the disease in patients from Argentina, we conducted a systematic search for mutations in the glucocerebrosidase gene. Genomic DNA from 31 unrelated GD patients was screened for seven previously described mutations: N370S (1226A-->G), L444P (1448T-->C), D409H (1342G-->C), R463C (1504C-->T), 1263de155, RecNciI, and RecTL. This allowed the identification of 77.4% of the GD alleles: N370S and RecNciI were the most prevalent mutations found (46.8% and 21% respectively). Southern analysis demonstrated three distinct patterns for the RecNciI alleles. In order to identify the remaining alleles, the full coding region of the gene, all the splice sites, and part of the promoter region were analyzed by single-strand conformational polymorphism analysis (SSCP) after polymerase chain reaction amplification. This extensive screening allowed the identification of 13 different mutations, accounting for 93% of the total number of GD alleles. Three novel missense mutations, I161S (599T-->G), G265D (911G-->A), and F411I (1348T-->A), were detected. Twelve polymorphic sites within the glucocerebrosidase gene are in complete linkage disequilibrium and define two major haplotypes, "-" and "+". Mutation N370S was always associated with the "-" haplotype, as described in other populations. Interestingly, the RecNciI alleles with the same Southern-blot pattern were always associated with the same haplotype.

Alleles↗
PubMed1998

Combined DNA immunization with the glycoprotein gene of viral hemorrhagic septicemia virus and infectious hematopoietic necrosis virus induces double-specific protective immunity and nonspecific response in rainbow trout.

Glycoprotein (G) of viral hemorrhagic septicemia virus (VHSV) and infectious hematopoietic necrosis virus (IHNV) contains several neutralizing epitopes. However, recombinant G protein never matches intact viral particles for immunogenicity. DNA immunization offers the possibility to deliver the antigen through the cellular machinery, thus mimicking natural infection. We constructed pCDNA gVHS and pCDNA gIHN plasmids with the G gene of VHSV and IHNV under the control of the CMV promoter, and we tested the plasmids for the accurate G protein expression prior to their use in fish immunization. Following intramuscular injection to adult rainbow trout, plasmid DNA was found inside the muscle cells shortly after injection and was still present 45 days later. mRNA of the G protein was detected in muscle tissue extracts, and the G protein was found within muscle cells at the site of injection. This resulted in the synthesis of high levels of specific neutralizing and protective antibodies. Fish injected with pCDNA gVHS and pCDNA gIHN in combination responded similarly to fish receiving one recombinant plasmid. In addition to the elicitation of a strong humoral response, DNA immunization was able to activate specialized cells of the immune system as well as nonspecific defense mechanisms, since mRNAs of MHC class II and Mx were strongly activated at the site of injection.

Animals↗
PubMed1998

Detection of oxidative mutagenesis by isoniazid and other hydrazine derivatives in Escherichia coli WP2 tester strain IC203, deficient in OxyR: strong protective effects of rat liver S9.

Strain IC203, deficient in the OxyR function, was sensitive to both cytotoxic and mutagenic effects of isoniazid (INH) whereas its parent, WP2 uvrA/pKM101, was resistant to these effects. Four other hydrazine compounds, hydrazine hydrate (HZH), phenylhydrazine (PHZ), hydralazine (HLZ) and nialamide (NLD), were mutagenic in WP2 uvrA/pKM101. Increases in mutagenicity were observed in IC203 for HZH and PHZ but not for HLZ and NLD. Growth inhibition zones by HZH, PHZ and NLD were larger in IC203 than in WP2 uvrA/pKM101. The enhancements in the effects of INH, HZH and PHZ in IC203 with respect to its oxyR+ parent are considered to be caused by the production of reactive oxygen species. This is consistent with its inhibition in IC203 by S9 from liver of uninduced rats, probably through the action of catalase. Mutagenicities of INH, PHZ and HLZ were low in strains IC204, a derivative of WP2 uvrA carrying a deletion of the umuDC genes, and IC206, a derivative of IC204 deficient in the MutY glycosylase. In these strains, HZH and NLD induced a high level of revertants which carry suppressor mutations resulting exclusively from G:C-A:T transitions, thus suggesting a direct reaction of the two hydrazines with cytosine.

Animals↗
PubMed1998

Molybdophosphoric Acid Adsorption on Titania from Ethanol-Water Solutions.

The equilibrium adsorption at 20 degreesC of molybdophosphoric acid solutions, using ethanol-water as solvent, on titania was studied. The molybdenum adsorption isotherm showed a sigmoidal shape; low values of molybdenum adsorbed were observed for final equilibrium concentrations lower than 50 mg Mo/ml, and for higher concentrations, the adsorbed molybdenum amount almost reached a plateau. From this isotherm it could be concluded that the solute-support interaction was not strong. UV-visible and NMR spectra of the solutions before and after the adsorption on titania showed that the species PMo12O3- 40 was present. This species also was observed by DRS in the wet samples and by NMR, FT-IR, and DRS, in the solid samples dried at room temperature and calcined at 255, 310, 365, and 425 degreesC, showing that the thermal stability of molybdophosphoric acid adsorbed on titania is similar to that of the bulk acid. The impregnating solutions and the impregnated solid changed with the time to a bluish color as a consequence of the formation of heteropoly blues which presented Mo6+ partially reduced to Mo5+. The XRD patterns indicated that the species adsorbed onto the support surface are highly dispersed like a noncrystalline form. Copyright 1998 Academic Press.

Journal Article↗
PubMed1998

Serotypes of Escherichia coli isolated from septicaemic chickens in Galicia (northwest Spain).

The purpose of this study was to establish the serogroups of Escherichia coli that cause avian colibacillosis in Spain. The serogroups of 625 avian E. coli isolated between 1992 and 1993 were determined. The 458 E. coli from chickens with septicaemia belonged to 62 different O serogroups; however, 59% were of one of 18 serogroups (O1, O2, O5, O8, O12, O14, O15, O18, O20, O53, O78, O81, O83, O102, O103, O115, O116 and O132). These 18 serogroups were also determined as an important percentage (29%) of control isolates from faeces of healthy birds. Nevertheless, a significant difference (59% versus 29%; P < 0.001) was observed. Furthermore, the serogroups O12, O14, O18, O53, O78, O81, O102, O115, O116 and O132 were almost exclusively identified among septicaemic E. coli (31% versus 3%; P < 0.001). The high prevalence of O18, O81, O115, O116 and O132 isolates was not expected and may indicate the emergence of five new serogroups associated with avian colibacillosis not yet reported.

Animals↗
PubMed1998

New Escherichia coli WP2 tester strains highly sensitive to reversion by oxidative mutagens.

New Escherichia coli strains have been added to the WP2 mutagenicity test for the specific detection of oxidative mutagens. Strain IC203 derives from WP2 uvrA/pKM101 and is highly sensitive to oxidative stress due to a deficiency in the OxyR function. Following exposure to t-butyl hydroperoxide (BuOOH) or menadione (MD), but not to 4-nitroquinoline 1-oxide (4NQO), strain IC203 (oxyR) shows increased mutability with respect to the oxyR+ parent. The advantage that the OxyR deficiency confers on IC203 strain in detecting oxidative mutagens is not obtained with strains deficient in either katG or ahpCF, two OxyR-regulated genes. Strain IC206, a derivative of WP2 uvrA carrying a deletion of the umuDC genes and deficient in the MutY glycosylase, has also been added to the WP2 test for the detection of SOS-independent mutations promoted by 8-oxoguanine lesions. Induction of these mutations was observed after treatment with BuOOH, but not after MD or 4NQO exposure. The two new strains, IC203 and IC206, can be useful for the screening of mutations resulting from oxidative stress as well as in studies on antioxidants preventing mutagenesis.

DNA-Binding Proteins↗
PubMed1998

Chiral and nonchiral determination of ketoprofen in pharmaceuticals by capillary zone electrophoresis.

The new method for the enantiomeric resolution of various 2-arylpropionic acids by capillary zone electrophoresis (CZE) using heptakis-tri-O-methyl-beta-cyclodextrin as chiral selector was applied to the determination of ketoprofen in different commercially-available pharmaceutical preparations. The analyte was determined under chiral and nonchiral conditions (viz. in the presence and absence of 50 mM heptakis-tri-O-methyl-beta-cyclodextrin in the background electrolyte), with significantly similar results and relative standard deviations from 1.2 to 6.5% in both cases. The limits of detection and determination for the inactive enantiomer, R-(-)-ketoprofen, were calculated to be 7.0 x 10(-7) and 1.6 x 10(-6) M, respectively. The proposed method was successfully used to determine enantiomeric purity in the drugs studied, with results comparable to those provided by the chiral HPLC method.

Anti-Inflammatory Agents, Non-Steroidal↗