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1.
JDR Clin Trans Res ; 3(4): 366-375, 2018 Oct.
Article in English | MEDLINE | ID: mdl-30238061

ABSTRACT

INTRODUCTION: In a randomized controlled trial, the effectiveness of motivational interviewing (MI) combined with enhanced community services (MI + ECS) was compared with ECS alone for reducing dental caries in American Indian children on the Pine Ridge Reservation. The intervention was developed and delivered with extensive tribal collaboration. METHODS: A total 579 mother-newborn dyads were enrolled and randomized to the MI + ECS and ECS groups. They were followed for 36 mo. Four MI sessions were provided, the first shortly after childbirth and then 6, 12, and 18 mo later. Both groups were exposed to ECS, which included public service announcements through billboards and tribal radio, as well as broad distribution of brochures on behavioral risk factors for early childhood caries (ECC), toothbrushes, and toothpaste. MI impact was measured as decayed, missing, and filled tooth surfaces (dmfs). Secondary outcomes included decayed surfaces, caries prevalence, and maternal oral health knowledge and behaviors. Modified intention-to-treat analyses were conducted. Eighty-eight percent of mothers completed at least 3 of 4 MI sessions offered. RESULTS: After 3 y, dmfs was not significantly different for the 2 groups (MI + ECS = 10, ECS = 10.38, P = 0.68). In both groups, prevalence of caries experience was 7% to 9% after 1 y, 35% to 36% at 2 y, and 55% to 56% at 3 y. Mean knowledge scores increased by 5.0, 5.3, and 5.9 percentage points at years 1, 2, and 3 in the MI + ECS group and by 1.9, 3.3, and 5.0 percentage points in the ECS group (P = 0.03), respectively. Mean maternal oral health behavior scores were not statistically significantly different between the treatment arms. CONCLUSION: In summary, the MI intervention appeared to improve maternal knowledge but had no effect on oral health behaviors or on the progression of ECC (ClinicalTrials.gov NCT01116726). KNOWLEDGE TRANSFER STATEMENT: The findings of this study suggest that motivational interviewing focusing on parental behaviors may not be as effective as previously hoped for slowing the development of childhood caries in some high-risk groups. Furthermore, social factors may be even more salient determinants of oral health than what we previously supposed, perhaps interfering with the capacity to benefit from behavioral strategies that have been useful elsewhere. The improvement of children's oral health in high-risk populations characterized by poverty and multiple related life stresses may require more holistic approaches that address these formidable barriers.

2.
J Dent Res ; 95(11): 1237-44, 2016 Oct.
Article in English | MEDLINE | ID: mdl-27439724

ABSTRACT

The authors tested the effectiveness of a community-based, tribally delivered oral health promotion (OHP) intervention (INT) at reducing caries increment in Navajo children attending Head Start. In a 3-y cluster-randomized trial, we developed an OHP INT with Navajo input that was delivered by trained Navajo lay health workers to children attending 52 Navajo Head Start classrooms (26 INT, 26 usual care [UC]). The INT was designed as a highly personalized set of oral health-focused interactions (5 for children and 4 for parents), along with 4 fluoride varnish applications delivered in Head Start during academic years of 2011 to 2012 and 2012 to 2013. The authors evaluated INT impact on decayed, missing, and filled tooth surfaces (dmfs) increment compared with UC. Other outcomes included caries prevalence and caregiver oral health-related knowledge and behaviors. Modified intention-to-treat and per-protocol analyses were conducted. The authors enrolled 1,016 caregiver-child dyads. Baseline mean dmfs/caries prevalence equaled 19.9/86.5% for the INT group and 22.8/90.1% for the UC group, respectively. INT adherence was 53% (i.e., ≥3 child OHP events, ≥1 caregiver OHP events, and ≥3 fluoride varnish). After 3 y, dmfs increased in both groups (+12.9 INT vs. +10.8 UC; P = 0.216), as did caries prevalence (86.5% to 96.6% INT vs. 90.1% to 98.2% UC; P = 0.808) in a modified intention-to-treat analysis of 897 caregiver-child dyads receiving 1 y of INT. Caregiver oral health knowledge scores improved in both groups (75.1% to 81.2% INT vs. 73.6% to 79.5% UC; P = 0.369). Caregiver oral health behavior scores improved more rapidly in the INT group versus the UC group (P = 0.006). The dmfs increment was smaller among adherent INT children (+8.9) than among UC children (+10.8; P = 0.028) in a per-protocol analysis. In conclusion, the severity of dental disease in Navajo Head Start children is extreme and difficult to improve. The authors argue that successful approaches to prevention may require even more highly personalized approaches shaped by cultural perspectives and attentive to the social determinants of oral health (ClinicalTrials.gov NCT01116739).


Subject(s)
Health Promotion/methods , Oral Health , Child, Preschool , DMF Index , Dental Caries/epidemiology , Dental Caries/prevention & control , Female , Health Services, Indigenous , Humans , Indians, North American , Male
3.
Health Educ Res ; 31(1): 70-81, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26612050

ABSTRACT

Health literacy is 'the capacity to obtain, process and understand basic health information and services needed to make appropriate health decisions'. Although numerous studies show a link between health literacy and clinical outcomes, little research has examined the association of health literacy with oral health. No large-scale studies have assessed these relationships among American Indians, a population at risk for limited health literacy and oral health problems. This analysis was conducted as part of a clinical trial aimed at reducing dental decay among preschoolers in the Navajo Nation Head Start program. Using baseline data for 1016 parent-child dyads, we examined the association of parental health literacy with parents' oral health knowledge, attitudes, and behavior, as well as indicators of parental and pediatric oral health. More limited health literacy was associated with lower levels of oral health knowledge, more negative oral health attitudes, and lower levels of adherence to recommended oral health behavior. Parents with more limited health literacy also had significantly worse oral health status (OHS) and reported their children to have significantly worse oral health-related quality of life. These results highlight the importance of oral health promotion interventions that are sensitive to the needs of participants with limited health literacy.


Subject(s)
Child Health , Health Literacy , Indians, North American , Oral Health/education , Parents/education , Adult , Aged , Aged, 80 and over , Child, Preschool , Female , Health Knowledge, Attitudes, Practice , Humans , Male , Middle Aged , Young Adult
4.
Transplant Proc ; 42(4): 1200-3, 2010 May.
Article in English | MEDLINE | ID: mdl-20534261

ABSTRACT

Hepatitis C virus (HCV) recurrence after orthotopic liver transplantation (OLT) is almost universal; cirrhosis develops in up to 30% of cases. Currently there is interest in the midterm outcomes of HCV patients with concomitant hepatitis B virus (HBV) infection among OLT recipients. We therefore retrospectively analyzed our database of patients who underwent OLT for HCV-HBV-related cirrhosis. Between April 1992 and December 2008, 350 patients underwent OLT, including 20 (5.7%) transplanted for HBV-HCV cirrhosis. We assessed patient and graft survivals at 1 and 5 years, as well as the progression of fibrosis. Protocol liver biopsies were available yearly after OLT. The survival curves were analyzed by the Kaplan-Meier approach and chronic hepatitis evaluated according to the Ishak scoring system. At a median follow-up of 68.4 +/- 53 months, the 1- and 5-year patient and graft survival rates were 80% and 70%, respectively. The 5-year fibrosis progression rate was 0.17 +/- 0.08 units of fibrosis. The only patient who developed histologic cirrhosis within 10 years of follow-up showed a lamivudine-resistant HBV recurrence. Patients transplanted for HBV-HCV coinfection showed a lower fibrosis progression rate compared with HCV monoinfected subjects.


Subject(s)
Hepatitis B/surgery , Hepatitis C/surgery , Liver Transplantation/physiology , Azathioprine/therapeutic use , Cyclosporine/therapeutic use , Graft Survival , Hepatitis B/immunology , Hepatitis C/immunology , Humans , Immunoglobulins/therapeutic use , Immunosuppressive Agents/therapeutic use , Liver Transplantation/immunology , Liver Transplantation/mortality , Prednisone/therapeutic use , Retrospective Studies , Survival Rate , Tacrolimus/therapeutic use , Treatment Outcome
7.
Eur J Hum Genet ; 9(4): 311-5, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11313776

ABSTRACT

Mitochondrial DNA (mtDNA) mutations have been causally linked with cardiomyopathies, both dilated (DCM) and hypertrophic. We identified the T12297C mutation in the mtDNA-tRNA(Leu(CUN)) of a 36-year-old male patient diagnosed with DCM. The mutation was heteroplasmic, with high amount (88%) of mutant DNA in the myocardium, and was absent in normal (n = 120) and disease (n = 150) controls. It affects a highly conserved nucleotide (adjacent to the anticodon triplet) that allows the phospho-ribose backbone to turn and form the loop. The potential pathological role of T12297C mutation is further supported by its recent identification in another unrelated Italian family with DCM associated with endocardial fibroelastosis. In the variable loop of the same tRNA, our patient also carried the A12308G transition that is debated as pathological mutation or neutral polymorphism in progressive external ophthalmoplegia: the two defects could exert a synergistic effect on the tRNA structure and function. The endomyocardial biopsy study showed abnormal ring-like mitochondria and occasional cytochrome c oxydase negative myocytes. Overall, the heteroplasmy, the highly conserved position of the mutated nucleotide, the absence of the mutation in large series of diseased and normal controls, and the cardiac mitochondrial changes support a causative link of the mutation with the disease.


Subject(s)
Cardiomyopathy, Dilated/genetics , Conserved Sequence , DNA, Mitochondrial , Mutation , RNA, Transfer, Leu , Adult , Base Sequence , Cardiomyopathy, Dilated/pathology , Humans , Male , Molecular Sequence Data , Nucleic Acid Conformation
8.
J Nucl Cardiol ; 8(1): 89-97, 2001.
Article in English | MEDLINE | ID: mdl-11182713

ABSTRACT

Myocardial tissue is highly dependent on energy supplied by normal mitochondrial function. Therefore defects of energy production or utilization affect the heart in both syndromic and isolated disorders. Knowledge of the peculiar structural, functional, and genetic characteristics of mitochondria provides the basis for identification and classification of mitochondrial defects as well as for establishment of a diagnostic workup useful for related cardiac disorders. This review is therefore dedicated to the characteristics of normal mitochondria and the pathologic alterations of these organelles in various cardiovascular diseases.


Subject(s)
Cardiomyopathies , Mitochondria, Heart , Cardiomyopathies/genetics , Cardiomyopathies/pathology , Cardiomyopathies/physiopathology , Humans , Mitochondria, Heart/diagnostic imaging , Mitochondria, Heart/genetics , Mitochondria, Heart/physiology , Mitochondrial Myopathies/genetics , Mitochondrial Myopathies/pathology , Mitochondrial Myopathies/physiopathology , Ultrasonography
9.
Mem Cognit ; 27(5): 768-78, 1999 Sep.
Article in English | MEDLINE | ID: mdl-10540806

ABSTRACT

In two experiments on Stroop interference, we examined whether sentences can be processed without the intention of the reader. Participants named the ink colors in which words in sentences were printed, and the ink colors in which the same words, randomly arranged, were printed. In Experiment 1, sentences yielded longer response times (RTs) and more errors than did nonsentences, but only when they included words that were highly relevant to the color-naming task (i.e., color and color-related words). In Experiment 2, sentences yielded more errors than did nonsentences, and sentences in which the color words matched the set of ink colors yielded longer RTs than did nonsentences. The results indicate that sentence processing can be obligatory when the component words are highly relevant to the task.


Subject(s)
Cognition , Inhibition, Psychological , Memory, Short-Term , Adult , Analysis of Variance , Female , Humans , Male , Psycholinguistics , Psychological Tests , Reaction Time
10.
Eur J Hum Genet ; 7(5): 603-8, 1999 Jul.
Article in English | MEDLINE | ID: mdl-10439969

ABSTRACT

We examined a set of populations mainly from Europe but also from the Middle East and North Africa for the three Y-linked microsatellites YCAII, DYS19 (about 1300 individuals) and DYS392 (about 350 individuals). Three markers (YCAII a5-b1 Ht, DYS19-190 bp and DYS392-254 bp) show decreasing gradients of frequency from western Europe towards the Middle East which parallel that of the proto-European 49a,f/TaqI Ht 15. Indeed, a strong linkage disequilibrium between these markers and the 49a,f Ht15 is observed. We therefore suggest that the 49a,f/TaqI Ht15, YCAII a5-b1 Ht, DYS19-190 bp and DYS392-254 bp Y chromosome could represent a component of the proto-European gene pool. This European specific compound haplotype distinctively characterises western Europeans and its very high incidence in these populations (particularly in the Basques) is discussed.


Subject(s)
Y Chromosome , Europe , Genetic Markers , Humans , Linkage Disequilibrium
11.
J Adolesc ; 22(2): 223-42, 1999 Apr.
Article in English | MEDLINE | ID: mdl-10089121

ABSTRACT

The direct effects of religiosity and racial socialization on subjective stigmatization among 50 African-American adolescents were investigated. A stigma is a characteristic about which others hold negative attitudes and stereotypes. Subjective stigmatization measures the degree to which an individual internalizes such negative attitudes and stereotypes toward a social group of which he or she is a member. Participants who showed strong commitment to the church were more destigmatized than were participants who did not. Further, participants who received racial socialization messages stemming from a single "primary" category were more destigmatized than those who did not. Unexpectedly, the more racial socialization messages participants received, the more self-stigmatized they were. The importance of religiosity and racial socialization in the lives of African-American adolescents are discussed.


Subject(s)
Black or African American/psychology , Prejudice , Psychology, Adolescent , Religion and Psychology , Socialization , Adolescent , Female , Humans , Male , Regression Analysis , Social Identification , United States
12.
Ann Hum Genet ; 63(Pt 2): 153-66, 1999 Mar.
Article in English | MEDLINE | ID: mdl-10738527

ABSTRACT

Two hypervariable Y-specific markers, the YCAII and DYS19 STRs, and the more stable Y Alu Polymorphism (YAP) have been analysed in about 1400 individuals of 21 different populations, mainly from Europe but also from the Middle East, Africa and Asia. On the basis of the frequency distributions of these three Y-markers we compare, using different statistical analyses, their power in detecting population genetic structure and in distinguishing closely related groups. The pattern of populations' genetic affinities inferred from the three markers considered altogether suggests a strong genetic structure that, with a few exceptions, broadly corresponds to the linguistic relatedness and/or geographic location of the sampled populations.


Subject(s)
Genetic Markers/genetics , Y Chromosome/genetics , Alleles , Asian People/genetics , Black People/genetics , DNA/genetics , Data Interpretation, Statistical , Genetic Variation , Geography , Haplotypes , Humans , Male , Polymorphism, Genetic , White People/genetics
13.
Hum Biol ; 70(4): 715-28, 1998 Aug.
Article in English | MEDLINE | ID: mdl-9686482

ABSTRACT

Anatolia, because of its geographic position and its use as an area of settlement, was also a land of transit that accommodated a succession of populations. The last important invasion occurred in the Middle Ages with the arrival of the Turks, an Altaic-speaking nomadic population descended from the Oguz tribes and originating in Mongolia. Although the Turks imposed their culture, their genetic contribution seems to have been modest. To validate this hypothesis, we studied the genetic structure of the Turkish population by examining 15 genetic markers in a sample of 93 subjects. The allele frequencies observed were HP*1 = 0.240; GLO1*1 = 0.344, ESD*2 = 0.134, GC*1S = 0.613, GC*1F = 0.129, PGM1*2S = 0.322, PGM1*2F = 0.041, PGM1*1F = 0.027, F13B*1 = 0.762, F13B*2 = 0.101, ORM1*S = 0.327, AHSG*2 = 0.181, C6*B = 0.239, C7*1 = 0.983, APOC2*1 = 1.0, APOE*3 = 0.868, APOE*2 = 0.063, BF*F = 0.258, BF*S07 = 0.017, BF*SQ0 = 0.011, C4A*Q0 = 0.145, C4A*2 = 0.070, C4A*5 = 0.012, C4A*6 = 0.023, C4B*Q0 = 0.101, C4B*2 = 0.048, C4B*3 = 0.005, and C4B*11 = 0.005. The present Turkish population was compared to other European, Middle Eastern, and North African populations by means of correspondence analysis. Turks cluster with Turkomans, who share the ancient Turks' derivation from the Oguz tribe. Moreover, Turks clearly belong to European groups and resemble the populations of neighboring countries. Therefore the present data support the hypothesis that the ancient Turkish tribes, who started to enter Anatolia 1000 years ago, contributed little to the gene pool of the preexisting Anatolian populations. Alternatively, if the genetic structure of the invading Turks resembled that of the ancient Anatolians, it will be impossible to find traces of their admixture with the autochthonous inhabitants of Anatolia. However, further analysis of other samples from Turkey and from populations living in the homelands of the Turkish tribes, namely, the eastern area of the Caspian Sea and Mongolia, is needed.


Subject(s)
Blood Proteins/genetics , Emigration and Immigration , Gene Frequency/genetics , Genetic Markers/genetics , Polymorphism, Genetic/genetics , Adult , Europe/ethnology , Female , Gene Pool , Humans , Male , Residence Characteristics , Turkey
15.
Hum Biol ; 66(5): 885-903, 1994 Oct.
Article in English | MEDLINE | ID: mdl-8001915

ABSTRACT

Using isoelectric focusing and immunoblotting techniques, we tested 270 plasma samples from 3 populations of Senegal (Wolof, Peul, Tukulor) to determine genetic variation at 7 protein loci (F13A, F13B, ORM1, AHSG, C6, C7, APOC2). Four of the seven systems (F13A, ORM1, AHSG, C6) have not been studied previously in sub-Saharan Africa, and one system (C7) has never been examined in any population of African ancestry. The assumption that F13B*6, F13B*23, and APOC2*2 represent African marker alleles is supported by this study. At the AHSG locus we observed a four-allele polymorphism rather than the two-allele polymorphism commonly seen in other ethnic groups. At the C6 locus, in addition to the two common alleles C6*A and C6*B, we observed three other alleles, one of which (C6*A3), found at polymorphic frequencies, seems to be another example of a unique African allele. The C7 locus was found to be monomorphic in the Peul but polymorphic in the Wolof and the Tukulor. At the F13A and ORM1 loci, Senegalese have allele frequencies similar to those reported for American blacks. All three Senegalese samples display typical African features, such as a high frequency of the F13B*2 allele and the presence of the APOC2*2 allele at a polymorphic level. However, some differences in allele frequencies have been found between the three groups, and this could have implications for reconstructing their remote history.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Blood Proteins/genetics , Genetic Variation , Genetics, Population , Polymorphism, Genetic , Alleles , Gene Frequency , Genetic Markers , Humans , Senegal
16.
Gene Geogr ; 8(1): 45-54, 1994 Apr.
Article in English | MEDLINE | ID: mdl-7619775

ABSTRACT

Mitochondrial DNA (mtDNA) variation was investigated in a group of 185 unrelated individuals (64 Czechoslovaks, 99 Northern and 28 Central Italians) using total blood DNA and the six restriction enzymes HpaI, BamHI, HaeII, MspI, AvaII and HincII. Among the 25 patterns (morphs) found, two morphs for HaeII, one for MspI and one for AvaII were new and each was represented by a single individual from Northern Italy. They account for four of the five new types encountered in this survey, being the fifth type characterized by the presence of the very rare morph HaeII-13. The populations analysed confirm the Caucasoid characteristics of certain polymorphisms. A review of the European data available so far is reported.


Subject(s)
Polymorphism, Genetic , Czechoslovakia , DNA, Mitochondrial/blood , DNA, Mitochondrial/genetics , Electrophoresis , Gene Frequency , Humans , Italy , Point Mutation , Polymorphism, Restriction Fragment Length , Restriction Mapping , White People/genetics
17.
J Chromatogr ; 553(1-2): 249-54, 1991 Aug 16.
Article in English | MEDLINE | ID: mdl-1787157

ABSTRACT

A method for the determination of acetone in plasma or urine by high-performance liquid chromatography (HPLC) was developed. Plasma specimens are deproteinized with acetonitrile (1:1, v/v) 2,4-dinitrophenylhydrazine (DNPH) is added to the supernatant or to filtered urine samples, similarly treated with acetonitrile (2:1, v/v) to prevent crystallization of the synthesized phenylhydrazone. An aliquot (20 microliters) of the reaction mixture was subjected to HPLC at ambient temperature using a reversed-phase Pecosphere 3 x 3 C18 column with acetonitrile-water (45:55, v/v) as eluent at a flow-rate of 1 ml/min and detection at 365 nm. Hydroxyacetone and acetoacetate phenylhydrazone derivatives do not interfere. The identification of acetone by its retention time was confirmed by comparison with a laboratory-synthesized acetone DNPH derivative. The concentration of acetone, eluted within 3 min, was determined by the peak-height method. The detection limit was 0.034 mmol/l; the relative standard deviations were less than 5% within run (n = 20) and less than 10% between run (n = 20).


Subject(s)
Acetone/metabolism , Acetone/blood , Acetone/urine , Chromatography, High Pressure Liquid , Humans , Male , Phenylhydrazines/chemistry
18.
Ann Hum Genet ; 55(2): 123-36, 1991 05.
Article in English | MEDLINE | ID: mdl-1719915

ABSTRACT

The polymorphisms of mitochondrial DNA for the restriction enzymes HpaI, BamHI, HaeII, MspI, AvaII and HinecII were studied in a sample of 79 Hindus, 45 from New Delhi (India) and 34 from Terai (Nepal), both to characterize another Caucasian population and to investigate some possible Hindu component in the genetic structure of the Tharus, a Nepalese population, the anthropological position of which is still disputed. 1. A new BamHI polymorphism was detected: about 5% of the Hindu mtDNAs have lost the site at 14258 bp and lack any BamHI site. Once again a BamHI polymorphism was found in a Caucasian population. 2. New site mutations were found to yield morphs previously described (MspI-7, AvaII-18). 3. Variant morphs for two different enzymes were found due to a shared mutation (morphs BamHI-0/AvaII-30 and morphs MspI-7Hindu/AvaII-18Hindu). 4. Comparison between Hindu and Tharu data does not show any evidence of a specific Indian component in the Tharu genetic structure and allows us to conclude that Tharus are clearly differentiated from modern Hindus.


Subject(s)
DNA, Mitochondrial/chemistry , Polymorphism, Restriction Fragment Length , Adult , DNA, Mitochondrial/classification , Deoxyribonuclease BamHI , Deoxyribonuclease HpaII , Deoxyribonucleases, Type II Site-Specific , Humans , India/ethnology , Male , Nepal/ethnology , White People/genetics
19.
Am J Hum Genet ; 48(2): 390-7, 1991 Feb.
Article in English | MEDLINE | ID: mdl-1990845

ABSTRACT

We have previously reported that the Tharu people of the Terai region in southern Nepal have an incidence of malaria about sevenfold lower than that of synpatric non-Tharu people. In order to find out whether this marked resistance against malaria has a genetic basis, we have now determined in these populations the prevalence of candidate protective genes and have performed in-vitro cultures of Plasmodium falciparum in both Tharu and non-Tharu red cells. We have found significant but relatively low and variable frequencies of beta-thal, beta S, G6PD (-), and Duffy (a-b-) in different parts of the Terai region. The average in-vitro rate of invasion and of parasite multiplication did not differ significantly in red cells from Tharus versus those from non-Tharu controls. By contrast, the frequency of alpha-thalassemia is uniformly high in Tharus, with the majority of them having the homozygous alpha-/alpha-genotype and an overall alpha-thal gene (alpha-) frequency of .8. We suggest that holoendemic malaria has caused preferential survival of subjects with alpha-thal and that this genetic factor has enabled the Tharus as a population to survive for centuries in a malaria-holoendemic area. From our data we estimate that the alpha-thal homozygous state decreases morbidity from malaria by about 10-fold. This is an example of selection evolution toward fixation of an otherwise abnormal gene.


Subject(s)
Malaria/prevention & control , Thalassemia/genetics , Animals , Blotting, Southern , DNA/genetics , Electrophoresis, Cellulose Acetate , Erythrocytes/parasitology , Genetic Markers , Heterozygote , Homozygote , Malaria/genetics , Nepal , Phenotype , Plasmodium falciparum/growth & development
20.
J Chromatogr ; 535(1-2): 311-6, 1990 Dec 28.
Article in English | MEDLINE | ID: mdl-2089061

ABSTRACT

A method for the biological monitoring of human exposure to aromatic hydrocarbons, nitrocompounds, amines and phenols has been developed. Phenol, cresols, p-aminophenol, p-nitrophenol and their glucorono- or sulpho-conjugates, were quantified by HPLC; 4-chlorphenol was added as internal standard. After enzymatic hydrolysis, the free compounds were extracted with an organic solvent and analyzed by an isocratic HPLC Perkin Elmer system at ambient temperature and at a flow-rate of 1 ml/min. The column was a reversed-phase Pecosphere 3 x 3 C18 Perkin Elmer; the mobile phase was a 30:70:0.1 (v/v/v) methanol-water-orthophosphoric acid mixture and the chromatogram was monitored at 215 nm. Identification was based on retention time and quantification was performed by automatic peak height determination, corrected for the internal standard. The recovery was ca. 95% for phenol and cresols; 90% for p-nitrophenol; 85% for p-aminophenol; the coefficients of variance were less than 6% within analysis (n = 20) and less than 10% between analysis (n = 20). The detection limits, at a signal/noise ratio of 2, were 0.5 mg/l for phenol and cresols and 1 mg/l for p-aminophenol and p-nitrophenol.


Subject(s)
Aminophenols/urine , Chromatography, High Pressure Liquid/methods , Cresols/urine , Nitrophenols/urine , Phenols/urine , Humans , Male
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