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M Blanco

Publications and source records attributed to M Blanco.

At least 37 records · Page 2Linked to original sources
PubMed2004

The clinical-DWI mismatch: a new diagnostic approach to the brain tissue at risk of infarction.

OBJECTIVE: To evaluate the usefulness of a mismatch between the severity of acute clinical manifestations and the diffusion-weighted imaging (DWI) lesion in predicting early stroke outcome and infarct volume. METHODS: One hundred sixty-six patients with a hemispheric ischemic stroke of <12 hours' duration were studied. The NIH Stroke Scale (NIHSS) score and the volume of DWI lesion were measured on admission and at 72 +/- 12 hours. Infarct volume was measured on T2-weighted or fluid-attenuated inversion recovery images at day 30. Early neurologic deterioration (END) was defined as an increase of > or =4 points between the two NIHSS evaluations. Thirty-eight patients received IV thrombolysis or abciximab. Clinical-DWI mismatch (CDM) was defined as NIHSS score of > or =8 and ischemic volume on DWI of < or =25 mL on admission. The adjusted influence of CDM on END, DWI lesion enlargement at 72 hours, and infarct growth at day 30 was evaluated by logistic regression analysis and generalized linear models. RESULTS: CDM was found in 87 patients (52.4%). Patients with CDM had a higher risk of END than patients without CDM because NIHSS < 8 (odds ratio [OR], 9.0; 95% CI,1.9 to 42) or DWI lesion > 25 mL (OR, 2.0; 95% CI, 0.8 to 4.9). CDM was associated with an increase of 46 to 68 mL in the mean volume of DWI lesion enlargement and infarct growth in comparison with non-CDM. All the effects were even greater and significant in patients not treated with reperfusion therapies. CONCLUSIONS: Acute stroke patients with an NIHSS score of > or =8 and DWI volume of < or =25 mL have a higher probability of infarct growth and early neurologic deterioration. The new concept of CDM may identify patients with tissue at risk of infarction for thrombolytic or neuroprotective drugs.

Aged↗
PubMed2004

Serotypes, virulence genes, and intimin types of Shiga toxin (verotoxin)-producing Escherichia coli isolates from human patients: prevalence in Lugo, Spain, from 1992 through 1999.

We have analyzed the prevalence of Shiga toxin-producing Escherichia coli (STEC) in stool specimens of patients with diarrhea or other gastrointestinal alterations from the Xeral-Calde Hospital of Lugo City (Spain). STEC strains were detected in 126 (2.5%) of 5,054 cases investigated, with a progressive increase in the incidence from 0% in 1992 to 4.4% in 1999. STEC O157:H7 was isolated in 24 cases (0.5%), whereas non-O157 STEC strains were isolated from 87 patients (1.7%). STEC strains were (after Salmonella and Campylobacter strains) the third most frequently recovered enteropathogenic bacteria. A total of 126 human STEC isolates were characterized in this study. PCR showed that 43 (34%) isolates carried stx(1) genes, 45 (36%) possessed stx(2) genes and 38 (30%) carried both stx(1) and stx(2). A total of 88 (70%) isolates carried an ehxA enterohemolysin gene, and 70 (56%) isolates possessed an eae intimin gene (27 isolates with type gamma1, 20 with type beta1, 8 with type zeta, 5 with type gamma2, and 3 with type epsilon). STEC isolates belonged to 41 O serogroups and 66 O:H serotypes, including 21 serotypes associated with hemolytic uremic syndrome and 30 new serotypes not previously reported among human STEC strains in other studies. Although the 126 STEC isolates belonged to 81 different seropathotypes (associations between serotypes and virulence genes), only four accounted for 31% of isolates. Seropathotype O157:H7 stx(1) stx(2) eae-gamma1 ehxA was the most common (13 isolates) followed by O157:H7 stx(2) eae-gamma1 ehxA (11 isolates), O26:H11 stx(1) eae-beta1 ehxA (11 isolates), and O111:H- stx(1) stx(2) eae-gamma2 ehxA (4 isolates). Our results suggest that STEC strains are a significant cause of human infections in Spain and confirm that in continental Europe, infections caused by STEC non-O157 strains are more common than those caused by O157:H7 isolates. The high prevalence of STEC strains (both O157:H7 and non-O157 strains) in human patients, and their association with serious complications, strongly supports the utilization of protocols for detection of all serotypes of STEC in Spanish clinical microbiology laboratories.

Adhesins, Bacterial↗
PubMed2004

Serotypes, virulence genes, and intimin types of Shiga toxin (verotoxin)-producing Escherichia coli isolates from cattle in Spain and identification of a new intimin variant gene (eae-xi).

A total of 514 Shiga toxin-producing Escherichia coli (STEC) isolates from diarrheic and healthy cattle in Spain were characterized in this study. PCR showed that 101 (20%) isolates carried stx(1) genes, 278 (54%) possessed stx(2) genes, and 135 (26%) possessed both stx(1) and stx(2). Enterohemolysin (ehxA) and intimin (eae) virulence genes were detected in 326 (63%) and in 151 (29%) of the isolates, respectively. STEC isolates belonged to 66 O serogroups and 113 O:H serotypes (including 23 new serotypes). However, 67% were of one of these 15 serogroups (O2, O4, O8, O20, O22, O26, O77, O91, O105, O113, O116, O157, O171, O174, and OX177) and 52% of the isolates belonged to only 10 serotypes (O4:H4, O20:H19, O22:H8, O26:H11, O77:H41, O105:H18, O113:H21, O157:H7, O171:H2, and ONT:H19). Although the 514 STEC isolates belonged to 164 different seropathotypes (associations between serotypes and virulence genes), only 12 accounted for 43% of isolates. Seropathotype O157:H7 stx(2) eae-gamma1 ehxA (46 isolates) was the most common, followed by O157:H7 stx(1) stx(2) eae-gamma1 ehxA (34 isolates), O113:H21 stx(2) (25 isolates), O22:H8 stx(1) stx(2) ehxA (15 isolates), O26:H11 stx(1) eae-beta1 ehxA (14 isolates), and O77:H41 stx(2) ehxA (14 isolates). Forty-one (22 of serotype O26:H11) isolates had intimin beta1, 82 O157:H7 isolates possessed intimin gamma1, three O111:H- isolates had intimin type gamma2, one O49:H- strain showed intimin type delta, 13 (six of serotype O103:H2) isolates had intimin type epsilon and eight (four of serotype O156:H-) isolates had intimin zeta. We have identified a new variant of the eae intimin gene designated xi (xi) in two isolates of serotype O80:H-. The majority (85%) of bovine STEC isolates belonged to serotypes previously found for human STEC organisms and 54% to serotypes associated with STEC organisms isolated from patients with hemolytic uremic syndrome. Thus, this study confirms that cattle are a major reservoir of STEC strains pathogenic for humans.

Adhesins, Bacterial↗
PubMed2004

Fecal shedding of Escherichia coli O157, Salmonella, and Campylobacter in Swiss cattle at slaughter.

Fecal samples from 2,930 slaughtered healthy cattle were examined with the following goals: (i) to monitor the shedding of Escherichia coli O157, Salmonella, and Campylobacter in cattle; and (ii) to further characterize the isolated strains. The percentage of the 2,930 samples that tested positive for E. coli O157 by PCR was 1.6%. Thirty-eight strains from different animals that agglutinated with Wellcolex E. coli O157 were isolated. Of the six sorbitol-negative strains, five tested positive for stx2 genes (two times for stx2c and three times for stx2), and one strain tested positive for stx1 and stx2c genes. All sorbitol-negative strains belonged to the serotypes O157:H7- and O157:H7 and harbored the eae type gamma 1 and ehxA genes. The 32 sorbitol-positive strains tested negative for stx genes and belonged to the serotypes O157:H2, O157:H7, O157:H8, O157:H12, O157:H19, O157:H25, O157:H27, O157:H38, O157:H43, O157:H45, and O157:H-. All O157:H45 strains harbored the eae subtype alpha 1 and therefore seem to be atypical enteropathogenic E. coli strains. Whereas none of 1,000 examined samples was positive for Salmonella, 95 of 935 (10.2%) samples were positive for Campylobacter, and all strains were identified as C. jejuni. Sixteen Campylobacter strains were resistant to tetracycline, five were resistant to nalidixic acid/ciprofloxacin, four were resistant to streptomycin, and one was resistant to nalidixic acid/ciprofloxacin and streptomycin. Fecal shedding of zoonotic pathogens in slaughter animals is strongly correlated with the hazard of carcass contamination. Therefore, the maintenance of slaughter hygiene is of crucial importance.

Animals↗
PubMed2003

Cellular distribution and regulation of ghrelin messenger ribonucleic acid in the rat pituitary gland.

Ghrelin, a 28-amino-acid acylated peptide, strongly stimulates GH release and food intake. In the present study, we found that ghrelin is expressed in somatotrophs, lactotrophs, and thyrotrophs but not in corticotrophs or gonadotrophs of rat pituitary. Persistent expression of the ghrelin gene is found during postnatal development in male and female rats, although the levels significantly decrease in both cases from pituitaries of 20-d-old rats onward, but at 60 d old, the levels were higher in male than female rats. This sexually dimorphic pattern appears to be mediated by estrogens because ovariectomy, but not orchidectomy, increases pituitary ghrelin mRNA levels. Taking into account that somatotroph cell function is markedly influenced by thyroid hormones, glucocorticoids, GH, and metabolic status, we also assessed such influence. We found that ghrelin mRNA levels decrease in hypothyroid- and glucocorticoid-treated rats, increase in GH-deficient rats (dwarf rats), and remain unaffected by food deprivation. In conclusion, we have defined the specific cell types that express ghrelin in the rat anterior pituitary gland. These data provide direct morphological evidence that ghrelin may well be acting in a paracrine-like fashion in the regulation of anterior pituitary cell function. In addition, we clearly demonstrate that pituitary ghrelin mRNA levels are age and gender dependent. Finally, we show that pituitary ghrelin mRNA levels are influenced by alteration on thyroid hormone, glucocorticoids, and GH levels but not by fasting, which indicates that the regulation of ghrelin gene expression is tissue specific.

Aging↗
PubMed2003

Development and validation of a method for the polymorphic analysis of pharmaceutical preparations using near infrared spectroscopy.

A new method for the characterization and determination of crystalline miokamycin in a pharmaceutical preparation using near infrared spectroscopy is proposed. The procedure involves the identification against a spectral library of samples with contents above the legal limit (viz. 5% of the crystalline form in amorphous miokamycin) using the Mahalanobis distance as the discriminating criterion, and the determination of the total and crystalline contents using partial least squares models that provide errors <1%. The proposed method was validated following the ICH guidelines. Its simplicity and expeditiousness make it highly suitable for quality control analyses of solid dosage forms.

Chemistry, Pharmaceutical↗
PubMed2003

[Lung cancer in the health care area of A Coruña (Spain): incidence, clinical approach and survival].

OBJECTIVE: To determine the incidence, clinical approach, diagnostic delay and survival for bronchogenic carcinoma (BC) in the public health area of A Coruña (Spain). PATIENTS AND METHOD: This was a retrospective study of patients with a diagnosis of BC made in 1995 and 1996 in a health care area with 509,000 inhabitants. For analysis we gathered demographic, clinical and cyto-histologic data and analyzed diagnostic delay, extension of disease and time of death. Crude, age-specific and age-standardized incidences were calculated. RESULTS: BC was diagnosed in 378 patients (95% men and 5% women). The crude incidence was 37 per 100,000 inhabitants (73.7 per 100,000 men and 3 per 100,000 women) and the age-standardized incidence was 21.7 per 100,000. Diagnosis was by cyto-histology in 87% of the cases, and the most frequent biopsy finding was epidermoid carcinoma. Diagnosis was by clinical or radiologic findings for 13.7%, and patients in that group were older and had greater comorbidity. No symptoms were present in 13% and in those patients diagnosis was earlier, with non-small BC predominating and 60% treated surgically. The diagnostic delay (time from the first symptom to histologic confirmation) was 2.5 months (median, 2.1), and length of delay did not affect survival. Surgery was performed in 23% of the patients with non-small BC. The median survival was 7.1 months (5.2 months for patients who were not treated surgically, and 37.6 for those who were). CONCLUSIONS: The incidence of BC in men in our study is consistent with that reported for other Spanish regions, although the incidence we observed for women is much lower. Diagnostic delay did not affect survival. The percentage of patients with surgical-stage disease is very low and survival is very short. These findings support the need for early diagnosis.

Aged↗
PubMed2003

Prevalence and characterization of Vero cytotoxin-producing Escherichia coli isolated from diarrhoeic and healthy sheep and goats.

Faecal samples from 146 diarrhoeic lambs and goat kids, and from 511 healthy sheep and goats were screened for the presence of Vero cytotoxin-producing Escherichia coli (VTEC). In healthy sheep and goats, VTEC were isolated in 24.4 and 16.2% of the animals, respectively. Moreover, VTEC were detected in 3.1 and 5.9% of the diarrhoeic lambs and goat kids, respectively. These data suggest that VTEC seems not to be associated with diarrhoea in lambs and goat kids. Only four VTEC strains were eae-positive. The absence of the eae gene in most of these VTEC strains could indicate that these strains are less virulent for humans that the classical eae-positive enterohaemorrhagic E. coli types. However, almost half (42.9%) and 12.2% of VTEC strains isolated from healthy sheep and goats, respectively, belonged to serotypes associated with severe diseases in humans.

Adhesins, Bacterial↗
PubMed2003

MOC-31/Ep-CAM immunoreactivity in Merkel cells and Merkel cell carcinomas.

AIMS: To evaluate the monoclonal antibody MOC-31 in Merkel cell carcinomas and normal Merkel cells. Merkel cell carcinoma is a rare and aggressive tumour that occurs mainly in elderly individuals. The histological diagnosis of Merkel cell carcinoma can be difficult because it looks similar to other small blue cell tumours, particularly skin metastases of small-cell lung carcinomas. This antibody recognizes the epithelial cell adhesion molecule (Ep-CAM), that has been assigned to the small cell lung cancer cluster 2 of antibodies. To the best of our knowledge, immunostaining for MOC-31/Ep-CAM has not been previously described in Merkel cells or Merkel cell carcinomas. METHODS AND RESULTS: Thirty-one cases of Merkel cell carcinoma and three samples of normal human fingertip were selected to analyse the expression of MOC-31/Ep-CAM by immunohistochemistry. A high number of Merkel cell carcinomas (21/31, 67.7%) showed intense and readily interpretable positivity. Immunostaining was diffuse or focal and always localized to the plasma membrane. Normal Merkel cells of human fingertip also showed plasma membrane immunoreactivity for MOC-31/Ep-CAM. CONCLUSION: The demonstration of positivity for MOC-31/Ep-CAM in Merkel cell carcinomas precludes the use of this immunohistochemical marker to distinguish between tumours and skin metastases of small-cell lung carcinoma.

Adult↗
PubMed2003

Serotypes, virulence genes, and intimin types of Shiga toxin (verotoxin)-producing Escherichia coli isolates from healthy sheep in Spain.

Fecal swabs obtained from 1,300 healthy lambs in 93 flocks in Spain in 1997 were examined for Shiga toxin-producing Escherichia coli (STEC). STEC O157:H7 strains were isolated from 5 (0.4%) animals in 4 flocks, and non-O157 STEC strains were isolated from 462 (36%) lambs in 63 flocks. A total of 384 ovine STEC strains were characterized in this study. PCR showed that 213 (55%) strains carried the stx(1) gene, 10 (3%) possessed the stx(2) gene, and 161 (42%) carried both the stx(1) and the stx(2) genes. Enterohemolysin (ehxA) and intimin (eae) virulence genes were detected in 106 (28%) and 23 (6%) of the STEC strains, respectively. The STEC strains belonged to 35 O serogroups and 64 O:H serotypes (including 18 new serotypes). However, 72% were of 1 of the following 12 serotypes: O5:H-, O6:H10, O91:H-, O117:H-, O128:H-, O128:H2, O136:H20, O146:H8, O146:H21, O156:H-, O166:H28, and ONT:H21 (where NT is nontypeable). Although the 384 STEC strains belonged to 95 different seropathotypes (associations between serotypes and virulence genes), 49% of strains belonged to only 11. O91:H- stx(1) stx(2) (54 strains) was the most common seropathotype, followed by O128:H- stx(1) stx(2) (33 strains) and O6:H10 stx(1) (25 strains). Three strains of serotypes O26:H11, O156:H11, and OX177:H11 had intimin type beta1; 5 strains of serotype O157:H7 possessed intimin type gamma1; and 15 strains of serotypes O49:H-, O52:H12, O156:H- (12 strains), and O156:H25 had the new intimin, intimin type zeta. The majority (82%) of ovine STEC strains belonged to serotypes previously found to be associated with human STEC strains, and 51% belonged to serotypes associated with STEC strains isolated from patients with hemolytic-uremic syndrome. Thus, this study confirms that healthy sheep are a major reservoir of STEC strains pathogenic for humans.

Adhesins, Bacterial↗
PubMed2002

Near infrared transflectance spectroscopy: determination of dexketoprofen in a hydrogel.

A new method for the determination of the active principle dexketoprofen (DKP) in a hydrogel using near infrared spectrometry was developed. A transflectance module allows the gel spectrum to be recorded with no sample pretreatment. Also, the PLS calibration method used allows low contents of the active principle in such a highly absorbing matrix as water/ethanol to be determined. The proposed method was validated and found to be an effective choice for the intended purpose.

Hydrogels↗
PubMed2002

Serobiotypes and virulence genes of Escherichia coli strains isolated from diarrheic and healthy rabbits in Brazil.

A total of 178 Escherichia coli isolates from diarrheic and healthy rabbits in the São Paulo State (Brazil) were serobiotyped and investigated by PCR for the presence of virulence genes. Among the 90 (50.6%) isolates which possessed the eae gene, 74 were from diarrheic animals and all but one encoded intimin beta. Sixty five (72.2%) of the eae+ isolates had insertion of the locus of enterocyte effacement locus in the pheU locus, 11 (12.2%) in the selC and 14 (15.6%) did not insert in either of these loci. All isolates were negative for genes of the E. coli enterotoxins, Stx1, Stx2, CNF1, CNF2 and EHEC hemolysin. The O132:H2 serotype was dominant, being present in 63 isolates (70%) of the 90 eae+ isolates, and 57 of the 63 isolates of this serotype belonged to biotype 30. PCR detected the gene for AF/R2 fimbriae in 75 (83.3%) of the 90 eae+ isolates. Adherence to HeLa cells was best detected following 6h incubation and a positive fluorescence actin staining (FAS) test was given by 52 isolates. These data show that isolates of E. coli associated with diarrhea in rabbits in Brazil possess the genotype and phenotype typically associated with rabbit enteropathogenic E. coli (EPEC). We conclude that EPEC that possess the eae gene are a common cause of diarrhea in Brazilian rabbit farms and that the pathogenic eae+ AF/R2+ isolates of O132:H2:B30 serobiotype are especially predominant.

Animals↗
PubMed2002

Pit-1/GHF-1 and GH expression in the MCF-7 human breast adenocarcinoma cell line.

GH expression in mammary tumors has been related to the increase and spreading of cell proliferation. Using the MCF-7 human breast adenocarcinoma cell line, it has been demonstrated that autocrine GH-stimulated mammary carcinoma cell proliferation decreased the apoptosis rate and enhanced cell spreading. Surprisingly, no data are available about the presence of Pit-1 (the main pituitary regulator of GH) or GH expression in this cell line. Using RT-PCR, Western blot and immunohistochemistry, we have demonstrated the presence of both mRNA coding Pit-1 and GH as well as Pit-1 and GH protein in the MCF-7 cell line. These data could imply that Pit-1 may be an adequate target to inhibit breast cell proliferation.

Adenocarcinoma↗
PubMed2001

Mutagenicity of nitric oxide-releasing compounds in Escherichia coli: effect of superoxide generation and evidence for two mutagenic mechanisms.

The mutagenicity of three nitric oxide (NO) donors, 3-morpholinosydnonimine (SIN-1), a compound generating the precursors of peroxynitrite NO and superoxide, diethylamine/NO (DEA/NO) and spermine/NO (SPER/NO), both releasing authentic NO was analyzed using Escherichia coli tester strains IC203, carrying a deletion of the oxyR gene, and its oxyR(+) parent IC188 (the alternative name of WP2 uvrA/pKM101). The OxyR protein is a redox-sensitive transcriptional activator of genes encoding antioxidant enzymes. Strains IC203 and IC188 contain error-prone DNA polymerases polV, encoded by the chromosomal umuDC genes, and polRI, encoded by mucAB genes carried by pKM101. SIN-1 was determined to be an oxidative mutagen giving a positive response only in IC203, whereas DEA/NO and SPER/NO induced similar positive responses in IC203 and IC188 and were considered as non-oxidative mutagens. The spectrum of ochre suppressors in Trp(+) revertants induced by SIN-1 in IC203 was characterized by a higher number of TA-->AT transversions and GC-->AT transitions, and a lower number of GC-->TA transversions, with respect to the untreated control. The mutagenicity of SIN-1 in IC203, probably induced by peroxynitrite through reactive derivatives, was enhanced in the presence of plumbagin (PLB), a superoxide generator. Superoxide generation by PLB, as well as formation of peroxynitrite in cells treated with SIN-1, evaluated by monitoring the oxidation, respectively, of dihydroethidium and dihydrorhodamine 123, were greater in IC203 than in IC188. Formation of peroxynitrite in IC203 treated with SIN-1 was stimulated by PLB. After treatment with DEA/NO and SPER/NO the number of revertants scored in IC188 was higher than in strains IC187, containing only polV, and IC204, deficient in both polV and polRI. For these compounds, induced suppressor revertants in IC187 and IC204 were almost exclusively GC-->AT transitions, whereas in IC188 significant levels of GC-->TA and TA-->AT transversions were also induced. Mutagenesis by both DEA/NO and SPER/NO was partially inhibited in the presence of PLB. The results show the usefulness of the new tester strain IC203 to differentiate NO-promoted mutagenic mechanisms that involve or do not involve oxygen radicals.

DNA Damage↗
PubMed2001

Localization of growth hormone receptors in rat and human thyroid cells.

Growth hormone (GH) exerts its multiple actions by binding to a specific receptor (GHR) widely distributed in the organism. It is well established that, in acromegaly, the thyroid gland is larger than normal and that GH increases triiodothyronin concentrations and decreases those of tetraiodothyronin (thyroxine). The aim of the present study was to analyze the presence of GHR and its mRNA in rat and human thyroid gland by Western blot, in situ hybridization techniques, and immunohistochemistry. A band of the expected size for GHR was shown in rat and human thyroid by Western blot. GHR immunoreactivity was found in virtually all follicles. The signal was mainly localized in the cytoplasm, although a nuclear positivity was also found. In situ hybridization techniques demonstrated the presence of GHR messenger RNA in the thyroid gland (cytoplasm of the follicular cells). These results provide direct morphological evidence that GHR is localized in the thyroid gland of mammals and opens up the possibility that GH regulates thyroid cell function directly or via local autocrine or paracrine production of insulin-like growth factor I.

Animals↗
PubMed2001

A phase I clinical trial of a multi-epitope polypeptide TAB9 combined with Montanide ISA 720 adjuvant in non-HIV-1 infected human volunteers.

A phase I clinical trial was performed to examine the safety and immunogenicity of a multi-epitope polypeptide comprising the central 15 amino acids of the V3 loop from six HIV-1 isolates. This protein called TAB9 was emulsified in Montanide ISA720 (Seppic, Paris) and administered intramuscularly at doses of 0, 0.2 and 1 mg to 24 healthy, HIV-1 seronegative adult males. Three immunisations were given at months 0, 1 and 6 in a randomised, double blind, placebo controlled clinical trial. The placebo was generally well tolerated. However, severe local reactions were observed in TAB9 vaccinated subjects after the second and third inoculations. Seven out of eight volunteers from the lower dose group showed moderate or severe local inflammation, while four out of eight subjects from the higher dose group developed granulomas and sterile abscesses. In general, the reactogenicity depended on the number of inoculations given and the dose of TAB9. Both doses were immunogenic, all immunised volunteers seroconverted and antibodies were broadly reactive against the V3 peptides included in the protein. All vaccine's sera reacted against gp120 in Western blot and 50% of them also neutralised at least one out of five laboratory isolates tested. No differences between doses were found. Anti TAB9 lymphoproliferative responses were observed, being more intense in the high dose group. Due to the strong local reactions that were found in this study, a change in the formulation will be required for further trials with this vaccine candidate in humans.

AIDS Vaccines↗
PubMed2001

Resolution of isomers of sorbitolparaben esters by chromatographic and electrophoretic techniques.

Pharmaceutical preparations usually contain preservatives and sweeteners. When parabens are used as preservatives and a polyol as a sweetener, a transesterification reaction may happen, yielding the transester polyol-paraben. The products formed in the transesterification reaction of methylparaben and sorbitol were analyzed by micellar electrokinetic chromatography and by HPLC. Up to six positional isomers of sorbitolparaben (SPB) can be produced. However, only three peaks were found by HPLC. The higher efficiency and resolution power of MEKC allowed one to resolve five peaks. Results were compared with those obtained by capillary zone electrophoresis in borate buffer, where the separation of isomers occurred in a different way, because of a complexation between SPB and borate.

Chromatography, High Pressure Liquid↗