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Biomedical subjects

R Cano

Publications and source records attributed to R Cano.

At least 19 recordsLinked to original sources

Application of genotypic and phenotypic analyses to commercial probiotic strain identity and relatedness.

AIMS: The objective of this study was to generate strain-specific genomic patterns of a bank of 67 commercial and reference probiotic strains, with a focus on probiotic lactobacilli. METHODS AND RESULTS: Pulsed-field gel electrophoresis (PFGE) was used as the primary method for strain differentiation. This method was compared with carbohydrate fermentation analysis. To supplement visual comparison, PFGE patterns were analysed quantitatively by cluster analysis using unweighted pair group method with arithmetic averages. SmaI, NotI and XbaI were found to effectively generate clear and easy-to-interpret PFGE patterns of a range of probiotic strains. Some probiotic strains from different sources shared highly similar PFGE patterns. CONCLUSIONS: Results document the value of genotypic strain identification methods, combined with phenotypic methods, for determining probiotic strain identity and relatedness. No correlation was found between relatedness determined by carbohydrate fermentation profiles alone compared with PFGE analysis alone. Some commercial strains are probably derived from similar sources. SIGNIFICANCE AND IMPACT OF THE STUDY: This approach is valuable to the probiotic industry to develop commercial strain identification patterns, to provide quality control of strain manufacturing production runs, to track use of protected strains and to determine the relatedness among different research and commercial probiotic strains.

Bacterial Typing Techniques↗

Legionnaires' disease clusters associated with travel to Spain during the period January 2001 to July 2003.

Epidemiological surveillance and control of travel associated cases of legionnaires' disease are necessary tasks for public health and collaboration between countries is necessary to do this. Within the framework of the European Surveillance Scheme for Travel Associated Legionnaires' Disease (EWGLINET), European Guidelines for Control and Prevention of Travel Associated Legionnaires' Disease have been produced . This has established the reporting and response criteria when cases or clusters appear. In this paper the analysis of the information corresponding to the 46 reported clusters related to Spain is presented. Data corresponds to the period January 2001 to July 2003.

Adult↗

Impact of the meningococcal C conjugate vaccine in Spain: an epidemiological and microbiological decision.

The new meningococcal C conjugate vaccine became available in Spain and was included in the infant vaccination schedule in 2000. A catch-up campaign was carried out in children under six years of age. As a consequence, the incidence of meningococcal disease caused by serogroup C has fallen sharply during the last three epidemiological years in Spain. The risk of contracting serogroup C disease in 2002/2003 fell by 58% when compared with the season before the conjugate vaccine was introduced. There was also an important decrease in mortality. Three deaths due to serogroup C occurred in the age groups targeted for vaccination in 2002/2003, compared with 30 deaths in the same age groups in the season before the launch of the vaccine campaign. In the catch-up campaign the vaccine coverage reached values above 92%. For the 2001, 2002 and 2003 routine childhood immunisation programme coverage values ranged from 90% to 95%. During the past three years a total of 111 cases of serogroup C disease have been reported in patients in the vaccine target group. Most of the vaccination failures occurred during the epidemiological year 2002/2003. Eight (53%) vaccine failures occurred in children who had been routinely immunised in infancy, and could be related to a lost of protection with time since vaccination. The isolation of several B:2a:P1.5 strains (ST-11 lineage) is noteworthy. These may have their origin in C:2a:P1.5 strains which, after undergoing genetic recombination at the capsular operon level, express serogroup B. These strains could have relevant epidemic potential.

Adolescent↗

Characterization of GIST/GIPACT tumors by inmunohistochemistry and exon 11 analysis of c-kit by PCR.

Gastrointestinal stromal tumors (GIST/GIPACT) are the most common mesenchymal tumors of the human gastrointestinal (GI) tract and are characterized by the constant immunohistochemical expression of CD117. In recent years, sporadic and germ line mutations in the c-kit gene have been described in GIST/GIPACT tumors, resulting in a constitutive activation of the gene. The most prevalent mutation is located in exon 11 of the c-kit gene, involved in the transcription of the juxta-membrane domain of the c-kit protein. There are conflicting reports with respect to the association between exon 11 mutations and the biological behavior of GIST/GIPACT tumors. This work studies eight patients with tumors diagnosed as GIST/GIPACT, both morphologically and immunohistochemically for CD117, CD34, a-smooth muscle actin, desmin and S-100 protein primary antibodies. The DNA of the eight cases was also studied by PCR for mutation of exon 11 of the c-kit gene. All cases were CD117 positive, but only two showed mutation of exon 11. These last two cases did not show morphological characteristics of malignancy. The most aggressive case, with early death of the patient, did not show the mutation. In conclusion, there was no correlation between the mutation of exon 11 of the c-kit gene and the malignant behavior of GIST/GIPACT tumors in our series.

Aged↗

Species-specific identification of commercial probiotic strains.

Products containing probiotic bacteria are gaining popularity, increasing the importance of their accurate speciation. Unfortunately, studies have suggested that improper labeling of probiotic species is common in commercial products. Species identification of a bank of commercial probiotic strains was attempted using partial 16S rDNA sequencing, carbohydrate fermentation analysis, and cellular fatty acid methyl ester analysis. Results from partial 16S rDNA sequencing indicated discrepancies between species designations for 26 out of 58 strains tested, including two ATCC Lactobacillus strains. When considering only the commercial strains obtained directly from the manufacturers, 14 of 29 strains carried species designations different from those obtained by partial 16S rDNA sequencing. Strains from six commercial products were species not listed on the label. The discrepancies mainly occurred in Lactobacillus acidophilus and Lactobacillus casei groups. Carbohydrate fermentation analysis was not sensitive enough to identify species within the L. acidophilus group. Fatty acid methyl ester analysis was found to be variable and inaccurate and is not recommended to identify probiotic lactobacilli.

Carbohydrate Metabolism↗

Biochemical characterization of a virus isolate, recovered from a patient with herpes keratitis, that was clinically resistant to acyclovir.

In vitro susceptibility assays of herpes simplex virus (HSV) do not necessarily correlate with treatment outcome. An HSV type 1 (HSV-1) isolate, N4, recovered from a patient who presented with herpes keratitis with localized immunosuppression, was characterized for susceptibility. Although the 50% inhibitory concentration (IC(50)) for this isolate was less than the accepted breakpoint for defining resistance to acyclovir (>2.0 microg/mL), the following lines of evidence suggest that the isolate was acyclovir resistant: (1) the clinical history confirmed that the infection was nonresponsive to acyclovir; (2) the in vitro susceptibility was similar to that of a thymidine kinase (TK)-negative, acyclovir-resistant virus SLU360; (3) the IC(50) of acyclovir was more than 10 times the IC(50) for an acyclovir-susceptible control strain; (4) plaque-purified clonal isolates were resistant to acyclovir (IC(50)s, >2.0 microg/mL); and (5) biochemical studies indicated that the HSV-1 N4 TK was partially impaired for acyclovir phosphorylation. Although residue changes were found in both the viral tk and pol coding regions of HSV-1 N4, characterization of a recombinant virus expressing the HSV-1 N4 polymerase suggested that the TK and Pol together conferred the acyclovir-resistance phenotype.

Acyclovir↗

Gemcitabine and vinorelbine in advanced nonsmall cell lung carcinoma: a phase II study.

BACKGROUND: The authors conducted a Phase II study to evaluate the activity of the combination of gemcitabine and vinorelbine in patients with advanced nonsmall cell lung carcinoma (NSCLC). METHODS: Patients were eligible if they had Stage IIIB (malignant pleural effusion) or Stage IV NSCLC, no prior chemotherapy, and Cancer and Leukemia Group B performance status (PS) 0-2. Patients with brain metastases were eligible if they were neurologically stable after brain irradiation. Thirty-three patients from participating institutions were enrolled. One patient was ineligible due to untreated brain metastases. Patients were treated with gemcitabine 1250 mg/m(2) over 30 minutes (1000 mg/m(2) for the first 6 patients) and vinorelbine 25 mg/m(2) over 6 minutes, both administered intravenously on Days 1 and 8 every 21 days. Treatment was planned for a total of six cycles or more if the patient had persistent benefit. Growth factors were not allowed. RESULTS: Among all 32 eligible patients, there were 8 partial responses, for an overall response rate of 25% (95% confidence interval [CI], 11.5-43. 4%). The median survival time was 8.3 months and the 1-year survival rate was 38% (95% CI, 24-59%). Patients with PS 0-1 had a median survival of 11.7 months and a 1-year survival rate of 48%. Grade 3 and 4 neutropenia was observed in 13% and 25% of the 148 treatment cycles, respectively. One patient died of neutropenic sepsis. Only 2 episodes of Grade 3 and 4 thrombocytopenia were observed. Nonhematologic toxicity was minimal. CONCLUSIONS: Gemcitabine and vinorelbine is an active and well-tolerated regimen in patients with advanced NSCLC, with response and survival rates at least comparable to those achieved with standard platinum-based regimens. This combination may be particularly suitable for the elderly or for patients who cannot tolerate more toxic platinum-based regimens.

Aged↗

Cruzipain induces autoimmune response against skeletal muscle and tissue damage in mice.

The goal of the current study was to investigate whether cruzipain, a major Trypanosoma cruzi antigen, is able to induce in mice an autoimmune response and skeletal muscle damage. We demonstrate that immunization with cruzipain triggers immunoglobulin G antibody binding to a 210-kDa antigen from a syngeneic skeletal muscle extract. The absorption of immune sera with purified myosin completely eliminated this reactivity, confirming that the protein identified is really myosin. We also found that spleen cells from immunized mice proliferated in response to a skeletal muscle extract rich in myosin and to purified myosin. Cells from control mice did not proliferate against any of the antigens tested. In addition, we observed an increase in plasma creatine kinase activity, a biochemical marker of muscle damage. Histological studies showed inflammatory infiltrates and myopathic changes in skeletal muscle of immunized animals. Electromyographic studies of these mice revealed changes such as are found in inflammatory or necrotic myopathy. Altogether, our results suggest that this experimental model provides strong evidence for a pathogenic role of anticruzipain immune response in the development of muscle tissue damage.

Animals↗

The ompB operon partially determines differential expression of OmpC in Salmonella typhi and Escherichia coli.

Expression of the Escherichia coli OmpC and OmpF outer membrane proteins is regulated by the osmolarity of the culture media. In contrast, expression of OmpC in Salmonella typhi is not influenced by osmolarity, while OmpF is regulated as in E. coli. To better understand the lack of osmoregulation of OmpC expression in S. typhi, we compared the expression of the ompC gene in S. typhi and E. coli, using ompC-lacZ fusions and outer membrane protein (OMP) electrophoretic profiles. S. typhi ompC expression levels in S. typhi were similar at low and high osmolarity along the growth curve, whereas osmoregulation of E. coli ompC in E. coli was observed during the exponential phase. Both genes were highly expressed at high and low osmolarity when present in S. typhi, while expression of both was regulated by osmolarity in E. coli. Complementation experiments with either the S. typhi or E. coli ompB operon in an S. typhi DeltaompB strain carrying the ompC-lacZ fusions showed that both S. typhi and E. coli ompC were not regulated by osmolarity when they were under the control of S. typhi ompB. Interestingly, in the same strain, both genes were osmoregulated under E. coli ompB. Surprisingly, in E. coli DeltaompB, they were both osmoregulated under S. typhi or E. coli ompB. Thus, the lack of osmoregulation of OmpC expression in S. typhi is determined in part by the ompB operon, as well as by other unknown trans-acting elements present in S. typhi.

Amino Acid Sequence↗

Multiple analysis of a foodborne outbreak caused by infant formula contaminated by an atypical Salmonella virchow strain.

An outbreak of food poisoning involving most autonomous Spanish communities was detected in the first half of 1994. The causative food was infant formula milk contaminated by lactose-fermenting Salmonella virchow. It was not possible to isolate the causative strain from the manufacturer's facilities. During the same period of time, there was a significant increase in lactose-non-fermenting Salmonella virchow strains compared with the same period in previous years. Simultaneously, lactose-non-fermenting strains were recovered from clinical samples from children and from some milk samples that were involved in the outbreak. Therefore, it was speculated that the outbreak might be more extensive than initially thought. The following epidemiological markers were used for typing the Salmonella virchow strains involved in the outbreak: (i) phage typing: (ii) ribotyping, using a set of 20 different endonucleases: and (iii) pulsed-field gel electrophoresis, using three different endonucleases. The most useful markers for this serotype were phage typing and pulsed-field gel electrophoresis, since ribotyping was not able to distinguish all strains tested. The results obtained revealed that the outbreak was caused by at least two strains: one presenting phage type 4-4a and pulsed-field patterns A1 or A2 and L+ or L-, and another presenting phage type 2 and pulsed-field patterns A1 or A2 and L+ or L-. The results indicate that the outbreak was more extensive than initially thought and that the Virchow serotype is very clonal in Spain.

Animals↗

The structure of streptonigrin semiquinone in solution.

Streptonigrin semiquinone (SQ.), a free radical intermediate implicated in the biological functioning of the antitumor antibiotic streptonigrin has been prepared and its structural properties in solution have been characterized. Through the use of electron paramagnetic resonance spectroscopy, the spin densities of the unpaired electron have been determined, indicating that the unpaired electron is largely confined to the quinolinesemiquinone moiety of the antibiotic. Unambiguous assignment of the hyperfine coupling constants was achieved employing isotopically labeled semiquinone radical, INDO molecular orbital calculations, and the study of unsubstituted 5,8-quinolinesemiquinone as a reference system. The assignments point to a negative spin density at the carbon para to the pyridine nitrogen in the radicals derived from both streptonigrin and the unsubstituted 5,8-quinolinequinone. Characterization of the properties of the streptonigrin semiquinone in solution indicate that the radical is stable in solution: it can be conveniently studied in 0.1 M methanolic lithium hydroxide or in aqueous organic solvent mixtures buffered with 0.06 M K3PO4 at pH 12.0. Under these conditions, the semiquinone shows completely reversible spectral changes between -10 to 60 degrees C. Lowering the pH from 12.0 to 7.0 in aqueous DMSO decreases the lifetime of the radical from two weeks to a few minutes. Changes in structural properties of streptonigrin semiquinone in solution have been found to occur mainly due to variation in solvation and freedom of rotation of the amino group. Decreasing the temperature of SQ. solution in methanol from 60 to -10 degrees C leads to an increase in the hyperfine coupling constant to the amino nitrogen from 1.28 to 1.40 G, and those of the two amino protons from 0.73 and 0.73 to 1.02 and 1.11 G respectively, while the other coupling constants change less than 3%. Greater electron spin delocalization onto the -NH2 group has been found throughout the solvent systems examined, yet the temperature at which

Antibiotics, Antineoplastic↗

Interregional foodborne salmonellosis outbreak due to powdered infant formula contaminated with lactose-fermenting Salmonella virchow.

Spain's Salmonella surveillance system backed by regionally-based epidemiologists around the country made it possible to detect and halt the spread of a foodborne salmonellosis outbreak due to powdered infant formula contaminated with a lactose-fermenting strain of Salmonella virchow. Forty-eight cases involving children, mostly under 7 months old, were detected in 14 out of Spain's 17 Regions. The outbreak started in January and ended in June 1994. All cases were microbiologically confirmed. The implicated strain had a 3.6 kb plasmid, was susceptible to all antimicrobials tested except nitrofurantoin and was phagetype 4a. Isolates from 8 of 24 Brand "A" milk samples tested had the same characteristics as case isolates. All affected/suspect batches of Brand "A" milk were destroyed and the product withdrawn from sale, which led to the end of the outbreak. This incident underscores the importance of maintaining surveillance systems able to detect and prevent foodborne outbreaks and alert to the possibility of isolating unusual lactose-fermenting Salmonella serotypes in especially sensitive food products.

Animals↗

[Analysis of Salmonella sp. serotypes isolated in Spain en 1988-1992].

BACKGROUND: Salmonella sp. is the main cause of bacterial diarrhoea in Spain. Serotyping, is the most widely applied epidemiological marker. The epidemiological distribution of Salmonella serotypes isolated in Spain is analyzed by statistical methods. METHODS: Salmonella isolates were serotyped according to standard methods and the results were analyzed by the Mantel-Haenszel chi 2 test. RESULTS AND CONCLUSIONS: The number of isolates (20,595) was 17% higher than those analyzed in the previous five year period (1983-1987), mainly due to an increase in the number of isolates from non human origin. The three most commonly isolated serotypes were Enteritidis, Typhimurium and Virchow. Serotype Enteritidis decreased along the analyzed period, probably because of the effectiveness of the socio-sanitary measures taken by the national and regional administrations such as legal issues (use of commercial mayonnaise in restaurants) and sanitary education.

Animals↗

Evaluation of a DNA probe of plasmid origin for the detection of Neisseria gonorrhoeae in cultures and clinical specimens.

This study evaluates a cryptic plasmid-derived DNA probe in a dot-blot hybridization assay of 4-h duration, using both known bacterial isolates and clinical specimens. The probe, consisting of a 237 bp segment of the plasmid-encoded gene cppB, sequences of which are also found in the chromosome, was labelled with digoxigenin-11-dUTP. The sensitivity of the probe was approximately 25 pg of DNA or 500 cfu of Neisseria gonorrhoeae. A total of 170 reference strains of Neisseria gonorrhoeae and other related bacteria were tested for reactivity with the probe. All N. gonorrhoeae strains, including three plasmid-free strains, hybridized with the probe. Among the heterologous bacterial cultures, only one strain of N. cinerea reacted with the probe when the cell concentration was 5 x 10(6) cfu. The probe was also evaluated in a clinical study. A total of 201 patients visiting the STD clinic at the University Hospital, University of Seville, participated in the study. The sensitivity of the assay was 95% while the specificity was 98%. Positive and negative predictive values were 97% and 98%, respectively. It appears that the plasmid-derived probe used in this study could serve as a useful tool in the rapid and specific detection of Neisseria gonorrhoeae in clinical specimens.

Cloning, Molecular↗