Biomedical subjects

Guillermo Mendoza

Publications and source records attributed to Guillermo Mendoza.

17 recordsLinked to original sources

PubMed2006

A single amino acid substitution on the surface of a natural hevein isoform (Hev b 6.0202), confers different IgE recognition.

Decreased immune reactivity of isoforms of major allergens has been reported. However, such claims have always been based on experiments with recombinant proteins. This work describes the molecular and physicochemical characterization of a hevein (Hev b 6.0201) natural isoform (Hev b 6.0202), which is present in rubber latex from Hevea brasiliensis. The isoallergen has a single substitution Asn14Asp, which gives rise to local differences in the surface potential, as observed from the crystal structure presented here. Besides, ELISA inhibition using serum pools of adult and pediatric patients showed reduced IgE-binding capacity ( approximately 27%) with the isoallergen. Overall, these results are relevant to delineate crucial residues involved in this dominant discontinuous epitope.

Amino Acid Sequence↗

PubMed2006

Validation of a beta-agonist long-term asthma control scale derived from computerized pharmacy data.

BACKGROUND: Asthma control has been defined clinically by using validated tools, but an asthma control scale using administrative data has not been reported. OBJECTIVE: We sought to validate a beta-agonist asthma control scale derived from administrative data. METHODS: Surveys that included validated asthma symptom and control tools were completed by a random sample of 2250 health maintenance organization members aged 18 to 56 years with persistent asthma. Linked computerized pharmacy data provided beta-agonist canister and oral corticosteroid dispensings. The proposed 4-level asthma control scale was based on the number of short-acting beta-agonist canisters dispensed in 12 months. Construct validity and predictive validity were assessed. RESULTS: For construct validity, factor analysis showed significant loading of the beta-agonist scale on the symptom control factor, and the beta-agonist scale was significantly related to the validated asthma control and symptom scales (r = 0.31, P < .0001). For predictive validity, each progressive level of the proposed beta-agonist control scale was associated with an increased risk of subsequent asthma hospitalizations or emergency department visits and oral corticosteroid use, independent of prior use. CONCLUSION: A scale based on the number of beta-agonists dispensed in a 1-year period and derived from administrative data reflects asthma symptom control over that period of time. This scale can help identify patients who are at risk for future acute asthma health care use. CLINICAL IMPLICATIONS: This information can be used in population management and by clinicians to assess long-term asthma control and identify patients who need intervention to prevent future morbidity.

Adolescent↗

PubMed2006

The controller-to-total asthma medication ratio is associated with patient-centered as well as utilization outcomes.

BACKGROUND: The ratio of controller medication to total asthma medications has been related to asthma utilization outcomes, but its relationship to patient-centered outcomes has not been explored. METHODS: Surveys that included validated asthma quality-of-life, control, and symptom severity tools were completed by a random sample of 2,250 health maintenance organization members aged 18 to 56 years who had persistent asthma. Linked computerized pharmacy data provided dispensing information on beta-agonist canisters and asthma controller medication. The ratio was calculated as the number of controller medications dispensed during the year of the survey divided by the total number medications (ie, inhaled beta-agonist plus controller medications) dispensed. The relationships of the optimal ratio cutoff to patient-centered outcomes and to subsequent acute asthma exacerbations were determined. RESULTS: Mean asthma quality-of-life, asthma control, and symptom severity scale scores were significantly (p < 0.0001) more favorable in patients with ratios of > or = 0.5. After adjusting for demographic characteristics, patients with ratios of > or = 0.5 were significantly less likely to have adverse results regarding asthma quality of life (odds ratio [OR], 0.65; 95% confidence interval [CI], 0.52 to 0.80), asthma control (OR, 0.62; 95% CI, 0.50 to 0.77), and symptom severity (OR, 0.53; 95% CI, 0.43 to 0.65), and were also less likely to experience subsequent asthma hospitalizations or emergency department visits (OR, 0.44; 95% CI, 0.26 to 0.74) than patients with lower ratios. CONCLUSION: A higher controller medication/total asthma medication ratio is associated with better patient-centered asthma outcomes as well as with reduced emergency hospital utilization. This adds further support to the use of the medication ratio as an asthma quality-of-care measure.

Adrenal Cortex Hormones↗

PubMed2006

Development and validation of a medication intensity scale derived from computerized pharmacy data that predicts emergency hospital utilization for persistent asthma.

OBJECTIVE: To validate a risk stratification scheme using computerized pharmacy data to predict emergency hospital utilization for persistent asthma. STUDY DESIGN: Retrospective cohort. METHODS: The development sample consisted of 1079 HMO members aged 18 to 56 years with persistent asthma. The scale used medication cut-points as predictors for next-year emergency hospital utilization in a stepwise logistic regression model. Prediction properties were evaluated in a validation sample of 24 370 patients aged 18 to 56 years in a separate persistent-asthma database. RESULTS: Increasing use of beta-agonists (odds ratio [OR] of 2.2 for 5-13 vs 0-4 canisters; OR of 2.4 for >13 vs 5-13 canisters) and oral corticosteroids (OR of 2.6 for >2 vs 0-2 dispensing events) in the first year independently predicted emergency hospital utilization in the second year. Assigning 1 point for exceeding each of the above 3 medication thresholds led to a 4-level medication intensity scale that was significantly (P <.0001) related to validated measures of asthma symptom severity, asthma control, and asthma quality of life in the development sample. In the validation sample, this scheme identified a high-risk group that was 6 times more likely than the low-risk group to require subsequent emergency hospital care, with overall sensitivity of 65% and specificity of 54%. This scale did not perform as well as a scale based on both baseline emergency hospital care and pharmacy data. CONCLUSION: This simple risk stratification scheme can be used for populations with persistent asthma for whom computerized pharmacy data, but not computerized prior utilization data, are available.

Adolescent↗

PubMed2005

Improved asthma outcomes from allergy specialist care: a population-based cross-sectional analysis.

BACKGROUND: Prior studies suggest that allergist care improves asthma outcomes, but many of these studies have methodological shortcomings. OBJECTIVE: We sought to compare patient-based and medical utilization outcomes in randomly selected asthmatic patients cared for by allergists versus primary care providers. METHODS: A random sample of 3568 patients enrolled in a staff model health maintenance organization who were given diagnoses of persistent asthma completed surveys. Of these participants, 1679 (47.1%) identified a primary care provider as their regular source of asthma care, 884 (24.8%) identified an allergist, 693 (19.4%) reported no regular source of asthma care, and 195 (5.5%) identified a pulmonologist. Validated quality of life, control, severity, patient satisfaction, and self-management knowledge tools and linked administrative data that captured medication use were compared between groups, adjusting for demographics and baseline hospital and corticosteroid use. RESULTS: Compared with those followed by primary care providers, patients of allergists reported significantly higher (P < .001) generic physical and asthma-specific quality of life, less asthma control problems, less severe symptoms, higher satisfaction with care, and greater self-management knowledge. Patients of allergists were less likely than patients of primary care providers to require an asthma hospitalization (odds ratio, 0.45) or unscheduled visit (odds ratio, 0.71) and to overuse beta-agonists (odds ratio, 0.47) and were more likely to receive inhaled steroids (odds ratio, 1.81) during their past year. CONCLUSIONS: Allergist care is associated with a wide range of improved outcomes in asthmatic patients compared with care provided by primary care providers.

Adult↗

PubMed2005

Survival to different acid challenges and outer membrane protein profiles of pathogenic Escherichia coli strains isolated from pozol, a Mexican typical maize fermented food.

In this study, the acid resistance and the changes in outer membrane protein (Omps) profiles of Escherichia coli strains isolated from pozol, an acid-fermented maize beverage consumed in Southeastern Mexico, were determined. Results showed that adaptation to acid by these E. coli strains significantly enhances their survival in acid conditions. Changes in Omp profiles were found in non-adapted acid challenged cells compared with non-challenged cells that had not been adapted to acid. Challenged adapted cells showed no significant changes in these profiles when compared with the acid adapted non-challenged strains. N-terminal sequences of some of the Omps were determined. The intensity of the main porins OmpC and OmpA was lower in the acid challenged strains, than in the non-challenged ones. The OmpF porin was identified in non-challenged K12 strain, but did not appear in adapted or non-adapted pozol strains nor in E. coli O157:H7. A protein band with an approximate molecular mass of 22 kDa corresponds to OmpW and its expression decreased in pozol strains challenged with HCl and lactic acid. OmpX was one of the main proteins expressed when strains were acid challenged with organic acids. Seventy out of seventy-three E. coli strains isolated from pozol in a previous work [Sainz, T., Wacher, C., Espinoza, J., Centurion, D., Navarro, A., Molina, J., Cravioto, A., Eslava, C., 2001. Survival and characterization of Escherichia coli strains in a typical Mexican acid-fermented food. International Journal of Food Microbiology 71, 169-176] carry this gene and belong to a reported pathogenic class of E. coli strains, or have virulence factors or survived at pH values less than 4.8. We suggest this protein could be involved in survival to stress conditions.

Adaptation, Physiological↗

PubMed2005

Relationship of validated psychometric tools to subsequent medical utilization for asthma.

BACKGROUND: Risk stratification is used to identify patients with asthma at increased risk of experiencing morbidity and resource utilization. Validated psychometric tools are infrequently studied sources of data for this purpose. PURPOSE: To evaluate 4 types of validated psychometric tools as predictors for subsequent asthma utilization and determine their clinical usefulness. METHODS: Eleven hundred patients with active asthma from a Health Maintenance Organization completed surveys that included demographic information and validated psychometric tools measuring generic quality of life (physical and mental components), asthma-specific quality of life, asthma control, and asthma symptom severity. Survey records were linked to administrative data that captured emergency department and hospital care, short-acting beta-agonist, and oral corticosteroid utilization for the year of and the year following the survey. Relationships of survey variables with subsequent utilization were assessed, adjusting for both baseline demographic and asthma utilization factors. RESULTS: Scores of each psychometric tool were significantly related to subsequent utilization in univariate analyses and after adjusting for baseline utilization and demographic risk factors. Patients with higher scale-defined morbidity were as much as 4 times more likely to have subsequent utilization (sensitivity as high as 58%; specificity as high as 78%). Addition of an asthma-specific tool to either demographic or utilization prediction models added sensitivity (as much as 15%) but did not substantially improve the prediction properties of models containing both demographic and utilization predictors. CONCLUSION: Validated psychometric tools appear useful for asthma risk stratification in individuals and in populations in which both utilization and demographic predictors are not available.

Adolescent↗

PubMed2005

Relationships among quality of life, severity, and control measures in asthma: an evaluation using factor analysis.

BACKGROUND: Validated psychometric tools measuring quality of life, asthma control, and asthma severity have been developed, but their relationships with each other and with other important patient-centered outcomes have not been rigorously assessed. OBJECTIVE: To use factor analysis to evaluate the relationships of these validated tools with each other and with other patient-centered outcomes. METHODS: Surveys were completed by a random sample of 2854 Health Maintenance Organization members age 18 to 56 years with persistent asthma. Surveys included demographic information; validated tools measuring generic (Short Form-12; SF-12) and asthma-specific (Juniper Mini Asthma Quality of Life Questionnaire; AQLQ) quality of life, asthma control (Asthma Therapy Assessment Questionnaire), and asthma symptom severity (Asthma Outcomes Monitoring System); self-described severity, control, and course over time; and history of acute exacerbations. RESULTS: Principal component analysis suggested a 5-factor model that accounted for approximately 59% of the variability. The most prominent rotated factor reflected asthma symptom frequency (19.4% of variability), was measured by the symptom subscale of the AQLQ, and was the only factor significantly related to the Asthma Therapy Assessment Questionnaire, Asthma Outcomes Monitoring System, or the self-reported assessments of severity, control, or course. Other factors included symptom bother (12.1% of variability), reflected by the environment and emotion AQLQ subscales; activity limitation (13.9% of variability), reflected by the activity AQLQ subscale and the SF-12 physical component scale; mental health (8.3% of variability), reflected by the SF-12 mental component scale; and acute exacerbations (5.0% of variability), not measured by any of the validated scales. CONCLUSION: Distinct components of patient-reported asthma health status can be identified by factor analysis. Distinct constructs of severity versus control cannot be identified by the use of these tools alone.

Adolescent↗

PubMed2005

Intensive care unit admission for asthma: a marker for severe disease.

BACKGROUND: There appears to be an asthma epidemic in the United States and other developed countries, with increasing prevalence and severity of asthma. Despite these trends, the understanding of severe asthma remains limited. Research has been hampered by the lack of clear methodology for identifying a cohort of adults with severe asthma. We systematically evaluated a method for defining a cohort of adults with severe asthma based on recent intensive care unit admissions for asthma. METHODS: We used survey interview and computerized utilization data from a cohort of 400 adults with severe asthma who were enrolled after hospitalization at 17 Northern California Kaiser Permanente hospitals. To assess asthma severity, we used a multifaceted approach that combined structured telephone interview data with computerized utilization data. Using a referent group of adults who were hospitalized without intensive care unit (ICU) admission (n=282), we examined whether ICU admission is a valid marker for severe disease (n=118). RESULTS: Adults with asthma who had recent ICU admission had greater severity-of-asthma scores, controlling for sociodemographic factors, smoking, and atopic history (mean score increment 2.3 points; 95% CI 1.3 to 3.2). The ICU subjects also had poorer asthma-specific quality of life (mean score increment 6.6 points; 95% CI 3.5 to 9.8) and were more likely to indicate severe self-perceived asthma (49% vs. 22%, p<0.0001). Adults with recent ICU admission were more likely to have seen an asthma specialist during the past year (27% vs. 16%). They were also more likely to have had an asthma-related emergency department visit (37% vs. 26%), hospitalization (17% vs. 6%), and ICU admission during the previous year (5% vs. 0.7%) (p<0.05 in all cases). Among the 311 adults with asthma who had continuous Kaiser Permanente pharmacy benefits for the previous 12 months, a greater proportion of the ICU group received inhaled corticosteroids during the 12 months prior to hospitalization (78% vs. 65%, p=0.024). CONCLUSIONS: Admission to the ICU for asthma identifies a subgroup with severe disease, providing a valid methodology for defining a cohort of adults with severe asthma.

Adult↗

PubMed2005

The impact of allergy and pulmonary specialist care on emergency asthma utilization in a large managed care organization.

OBJECTIVE: To evaluate the longitudinal impact of asthma specialist care on the risk of emergency department (ED) visits and hospitalization for asthma. DATA SOURCES/STUDY SETTING: A prospective cohort study using both telephone survey and computerized utilization data. STUDY DESIGN: We recruited a prospective cohort of 4,742 adult members of a closed panel managed care organization who were hospitalized for asthma (the "baseline hospitalization"). DATA COLLECTION/EXTRACTION METHODS: Visits to asthma specialists were ascertained from computerized utilization databases. Specialist visits after baseline hospitalization were defined as time-dependent covariates. An alternative analysis defined specialist visits during the year preceding baseline hospitalization. A subcohort of 596 subjects completed telephone interviews. PRINCIPAL FINDINGS: Compared with subjects who received no specialist visits after baseline hospitalization, treatment by allergists (hazard ratio (HR) 1.04; 95 percent confidence interval (CI) 0.87-1.26) or pulmonologists (HR 0.92; 95 percent CI 0.71-1.19) was not associated with a reduction in the risk of future ED visits for asthma in the entire cohort, controlling for age, sex, race, recent asthma medication dispensing, and pharmacy benefits status. There was also no association between allergist visits and the risk of subsequent hospitalizations for asthma (HR 0.93; 95 percent CI 0.75-1.14). In contrast, visits to pulmonologists (HR 0.74; 95 percent CI 0.55-0.99) were related to a reduced risk of rehospitalization. CONCLUSIONS: Pulmonary specialist visits appeared to reduce the risk of hospitalization for asthma, whereas asthma specialist visits did not reduce the risk of ED visits. In the context of comprehensive prepaid health care, the benefit of specialist care was modest.

Adult↗

PubMed2005

Asthma quality-of-care markers using administrative data.

STUDY OBJECTIVE: To evaluate the relationship of potential asthma quality-of-care markers to subsequent emergency hospital care. DESIGN: Retrospective administrative database analysis. SETTING: Managed care organization. PATIENTS: Asthmatic patients aged 5 to 56 years of age. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: Candidate quality measures included one or more or four or more controller medication canisters, a controller/total asthma medication ratio of > or = 0.3 or > or = 0.5, and the dispensing of fewer than six beta-agonist canisters in 2002. Outcome was a 2003 asthma emergency department visit or hospitalization. Multivariable analyses adjusted for age, sex, and year 2002 severity (based on utilization). In the total sample (n = 109,774), one or more controllers (odds ratio, 1.35) and four or more controllers (odds ratio, 1.98) were associated with an increased risk of emergency hospital care, whereas a controller/total asthma medication ratio of > or = 0.5 (odds ratio, 0.73) and the dispensing of fewer than six beta-agonist canisters (odds ratio 0.30) were associated with a decreased risk. After adjustment for baseline severity in the total asthma sample, the controller/total asthma medication ratio (odds ratio, 0.62 to 0.78) and beta-agonist measure (odds ratio, 0.42) were associated with decreased risk, whereas the dispensing of four or more canisters of controller medication was associated with increased risk (odds ratio, 1.33). After stratification by year 2002 beta-agonist use, all of the measures were associated with decreased risk in those who received fewer than six beta-agonist canisters, whereas all of the measures except the medication ratio of > or = 0.5 were associated with increased risk in the cohort who received six or more beta-agonist canisters. CONCLUSION: Controller use and beta-agonist use may function as severity indicators in large populations rather than as asthma quality-of-care markers. A medication ratio of > or = 0.5 appeared to function as the best quality-of-care marker in this study.

Adolescent↗

PubMed2005

How well do the HEDIS asthma inclusion criteria identify persistent asthma?

OBJECTIVES: (1) To determine if the Health Plan Employer Data and Information Set (HEDIS) asthma inclusion criteria consistently identify persistent asthma on a year-to-year basis and (2) to explore whether variation in the number of years of qualification is associated with medication and resource utilization outcomes. STUDY DESIGN: Retrospective observational study. METHODS: We identified 132 414 patients in a large healthcare program who were included in 1 or more HEDIS persistent asthma cohorts between 1999 and 2002 and who had continuous insurance and pharmacy benefit coverage for the entire 4-year observation period. Medication, emergency department, and hospital use in 2002 was identified using electronic claims and pharmacy information. RESULTS: Overall, 47.9% of the patients were identified as having persistent asthma in only 1 of 4 years, 40.8% had at least 2 consecutive years, and 28.2% had at least 3 consecutive years. In bivariate and multivariate analyses, more consecutive years of HEDIS persistent asthma qualification significantly increased the likelihood of frequent short-acting b-agonist use, inhaled antiinflammatory corticosteroid use, at least 1 emergency department visit, and at least 1 hospitalization. The strongest relationship was for 3 or more consecutive years of HEDIS qualification. CONCLUSIONS: A significant portion of the HEDIS persistent asthma cohort does not qualify on a year-to-year basis, suggesting that the current 1-year qualification period or the underlying administrative case definition for persistent asthma may be suboptimal. Further clinical validation studies are needed to determine the optimal criteria for a more useful HEDIS persistent asthma case definition.

Adolescent↗

PubMed2004

Insights into a conformational epitope of Hev b 6.02 (hevein).

Hevein (Hev b 6.02) is a major IgE-binding allergen in natural rubber latex and manufactured products. Both tryptophans (Trp(21) and Trp(23)) of the hevein molecule were chemically modified with BNPS-skatole (2-nitrophenylsulfenyl-3-methyl-3(')-bromoindolenine); derivatized allergen failed to significantly inhibit binding of serum IgE in ELISA assays. Similarly, skin prick tests showed that hevein-positive patients gave no response with the modified allergen. Dot blot experiments carried out with anti-hevein mono- and polyclonal antibodies confirmed the importance of Trp(21) and Trp(23) for antibody-recognition, and demonstrated the specific cross-reactivity of other molecules containing hevein-like domains. We also report the structure of Hev b 6.02 at an extended resolution (1.5A) and compare its surface properties around Trp residues with those of similar regions in other allergens. Overall our results indicate that the central part of the protein, which comprises three aromatic and other acidic and polar residues, constitutes a conformational epitope.

Allergens↗

PubMed2003

A novel double heme substitution produces a functional bo3 variant of the quinol oxidase aa3 of Bacillus cereus. Purification and paratial characterization.

A novel bo3-type quinol oxidase was highly purified from Bacillus cereus PYM1, a spontaneous mutant unable to synthesize heme A and therefore spectroscopically detectable cytochromes aa3 and caa3. The purified enzyme contained 12.4 nmol of heme O and 11.5 nmol of heme B mg-1 protein. The enzyme was composed of two subunits with an Mr of 51,000 and 30,000, respectively. Both subunits were immunoreactive to antibodies raised against the B cereus aa3 oxidase. Moreover, amino-terminal sequence analysis of the 30-kDa subunit revealed that the first 19 residues were identical to those from the 30-kDa subunit of the B. cereus aa3 oxidase. The purified bo3 oxidase failed to oxidize ferrrocytochrome c (neither yeast nor horse) but oxidized tetrachlorohydroquinol with an apparent Km of 498 microM, a Vmax of 21 micromol of O2 min-1mg-1, and a calculated turnover of 55 s-1. The quinol oxidase activity with tetrachlorohydroquinol was inhibited by potassium cyanide and 2-n-heptyl 4-hydroxyquinoline-N-oxide with an I50 of 24 and 300 microM, respectively. Our results demonstrate that the bo3 oxidase of this mutant is not the product of a new operon but instead is a cytochrome aa3 apoprotein encoded by the qox operon of the aa3 oxidase of B. cereus wild type promiscuously assembled with hemes B and O replacing heme A, producing a novel bo3 cytochrome. This is the first reported example of an enzymatically active promiscuous oxidase resulting from the simultaneous substitution of its original hemes in the high and low spin sites.

Amino Acid Sequence↗

PubMed2002

Health-related quality of life and future health care utilization for asthma.

BACKGROUND: Although health-related quality of life (HRQL) has been increasingly used as an outcome in asthma, its utility for identifying patients at risk for adverse asthma outcomes has not been established. OBJECTIVE: In a prospective cohort study, to evaluate the longitudinal impact of HRQL on future health care utilization and cost among adults with asthma, accounting for known risk factors for utilization. METHODS: A stratified random sample of 3,482 adult Northern CA Kaiser Permanente members with asthma was selected using computerized utilization databases and a screening survey item. Subjects completed a mail survey that included measures of generic (SF-12) and asthma-specific HRQL (ITG-Asthma Short Form battery). During the 12 months after survey completion, computerized utilization and cost data were ascertained. RESULTS: Better baseline asthma-specific HRQL was associated with a decreased risk of asthma-related emergency department visit or hospitalization during longitudinal followup (odds ratio per 10-point score increment 0.84; 95% confidence interval [CI] 0.74 to 0.95), controlling for demographic and clinical factors. Better baseline generic physical HRQL was associated with a decreased risk of future all-cause hospitalization (odds ratio 0.68; 95% CI 0.60 to 0.77). More favorable asthma-specific HRQL scores were also related to decreased asthma-related health care costs during the ensuing year (-0.086 log-dollars per 10-point score increment; 95% CI -0.11 to -0.06). Better generic physical HRQL scores were associated with lower total costs (-0.24 log-dollars; 95% CI -0.32 to -0.17). CONCLUSIONS: In a large cohort of adult health maintenance organization members with asthma, asthma-specific HRQL was associated with future asthma-related utilization and cost.

Adolescent↗

PubMed2002

AniA regulates reserve polymer accumulation and global protein expression in Rhizobium etli.

Previously, it was reported that the oxidative capacity and ability to grow on carbon sources such as pyruvate and glucose were severely diminished in the Rhizobium etli phaC::OmegaSm(r)/Sp(r) mutant CAR1, which is unable to synthesize poly-beta-hydroxybutyric acid (PHB) (M. A. Cevallos, S. Encarnación, A. Leija, Y. Mora, and J. Mora, J. Bacteriol. 178:1646-1654, 1996). By random Tn5 mutagenesis of the phaC strain, we isolated the mutants VEM57 and VEM58, both of which contained single Tn5 insertions and had recovered the ability to grow on pyruvate or glucose. Nucleotide sequencing of the region surrounding the Tn5 insertions showed that they had interrupted an open reading frame designated aniA based on its high deduced amino acid sequence identity to the aniA gene product of Sinorhizobium meliloti. R. etli aniA was located adjacent to and divergently transcribed from genes encoding the PHB biosynthetic enzymes beta-ketothiolase (PhaA) and acetoacetyl coenzyme A reductase (PhaB). An aniA::Tn5 mutant (VEM5854) was constructed and found to synthesize only 40% of the wild type level of PHB. Both VEM58 and VEM5854 produced significantly more extracellular polysaccharide than the wild type. Organic acid excretion and levels of intracellular reduced nucleotides were lowered to wild-type levels in VEM58 and VEM5854, in contrast to those of strain CAR1, which were significantly elevated. Proteome analysis of VEM58 showed a drastic alteration of protein expression, including the absence of a protein identified as PhaB. We propose that the aniA gene product plays an important role in directing carbon flow in R. etli.

Acyltransferases↗

PubMed2002

Calreticulin-like molecule in trophozoites of Entamoeba histolytica HM1:IMSS (Swissprot: accession P83003).

In this work, we report the partial sequence of a 51 kDa protein of Entamoeba histolytica that is highly immunogenic in humans. Partial sequencing of the N-terminal end showed that 18 of the first 20 amino acid residues of the protein were identified uniquely, indicating that the final product was a homogeneous protein preparation. The N-terminal sequence that was found was: KVYFEETFENGWKXIWSKW. Comparing the 19-amino acid sequence of the protein in automated databases shows significant similarity with amino acid sequences of the calreticulin-like protein of spinach leaves (77%) and of the calreticulin precursor of Dictyostelium discoideum (60%).

Amino Acid Sequence↗