Citations
All
Search in:AllTitleAbstractAuthor name
Publications
(2K+)
Patents
Grants
Pathways
Clinical trials
The language you are using is not recognised as English. To correctly search in your language please select Search and translation language
Publication
Journal: Journal of Allergy and Clinical Immunology: In Practice
July/13/2017
Abstract
BACKGROUND
Asthma and chronic obstructive pulmonary disease (COPD) result in more than 1 million hospitalizations annually. Most hospitalized patients misuse respiratory inhalers. This misuse can be corrected with in-person education; however, this strategy is resource intensive and skills wane quickly after discharge.
OBJECTIVE
The objective of this study was to develop and pilot a virtual teach-to-goal™ (V-TTG™) inhaler skill training module, using innovative adaptive learning technology.
METHODS
Eligible adults with asthma or COPD completed a V-TTG™ metered-dose inhaler session with tailored rounds of narrated demonstration and self-assessments. The primary outcome was the proportion of participants with inhaler misuse post- versus pre-V-TTG™; secondary analyses tested mastery, self-efficacy, and perceived versus actual inhaler skills. Analyses were tested with McNemar's χ2 test (P < .05).
RESULTS
Among 90 enrolled participants, the majority were African American (94%), female (62%), and had asthma (68%), with a mean age of 48 years. Among those completing both pre- and post-V-TTG™ (n = 83), misuse was significantly lower post- versus pre-V-TTG™ (24% vs 83%, P < .001). Mastery and confidence both improved significantly (46% vs 7%, P < 0.001; 83% vs 67%, P < .001) post- versus pre-V-TTG™. After V-TTG™, there was greater congruence between perceived versus actual inhaler skills (P < .01). No differences were seen in subgroup analyses for age, health literacy level, or diagnosis.
CONCLUSIONS
This study is the first to demonstrate the efficacy of adaptive V-TTG™ learning to teach the inhaler technique. V-TTG™ improved most participants' technique to an acceptable level, reached mastery for half, and also increased self-efficacy and actualized skill. V-TTG™ has potential to improve health care across care transitions.
Publication
Journal: Arquivos de Gastroenterologia
October/4/2011
Abstract
BACKGROUND
Patients with autoimmune rheumatologic conditions and celiac disease tend to have a variety of autoantibodies, many of which have no clear pathogenic role. The literature contains frequent reports of celiac disease being more prevalent in patients with rheumatologic diseases, although this remains controversial.
OBJECTIVE
To investigate the prevalence of positive serum tests for celiac disease, particularly IgA and IgG antigliadin (AGA) antibodies and IgA antiendomysium antibodies (EmA) in patients with autoimmune rheumatologic diseases. A second aim was to correlate positive serum tests with prednisone and immunosuppressant medication.
METHODS
A total of 190 adults and pediatric patients with a variety of autoimmune rheumatologic diseases (systemic lupus erythematosus, rheumatoid arthritis, juvenile rheumatoid arthritis and spondyloarthrophathies) were evaluated and tested for IgA and IgG antigliadin-antibodies and IgA antiendomysium antibodies. Patients with positive serum tests underwent endoscopic duodenal biopsies for pathology studies.
RESULTS
There were four positive sera (2.1%) for AGA IgA, all of which tested negative for AGA IgG and EmA. Three sera (1.6%) tested positive for AGA IgG; all were negative for AGA IgA and EmA. The EmA test at a 1:2.5 serum dilution tested positive in 94 patients (49.5%); at a 1:5 serum dilution it was positive in 41 patients (21.6%). Eleven subjects tested positive for EmA at 1:40 dilution; and all of these tested negative for IgA tissue antitransglutaminase (tTG) antibodies. Nine of the 11 EmA-positive patients and all 7 patients with positive antigliadin antibodies tests underwent duodenal endoscopic biopsies, and no significant changes were demonstrated in their duodenal mucosa. A positive EmA was associated with elevated optical density AGA IgA readings; however, there was no relationship between positive EmA and AGA IgG optical density readings. Prednisone and immunosuppressant use were unrelated to AGA IgA optical density readings or AGA IgG readings. These drugs were associated with fewer positive EmA tests.
CONCLUSIONS
Positive AGAA, AGAG or EmA results are probably nonspecific for the presence of celiac disease among autoimmune rheumatologic disease patients. The intake of prednisone and immunosuprressant drugs seems to reduce the prevalence of IgA EmA, but it does not interfere with antigliadin antibodies tests.Further studies are required to estimate more accurately the prevalence of this disease in rheumatologic patients.
Publication
Journal: Journal of Industrial Microbiology and Biotechnology
November/12/2018
Abstract
Putrescine is widely used in the industrial production of bioplastics, pharmaceuticals, agrochemicals, and surfactants. Because the highest titer of putrescine is much lower than that of its precursor L-ornithine reported in microorganisms to date, further work is needed to increase putrescine production in Corynebacterium glutamicum. We first compared 7 ornithine decarboxylase genes and found that the Enterobacter cloacae ornithine decarboxylase gene speC1 was most suitable for putrescine production in C. glutamicum. Increasing NADPH availability and blocking putrescine oxidation and acetylation were chosen as targets for metabolic engineering. The putrescine producer C. glutamicum PUT4 was first constructed by deleting puo, butA and snaA genes, and replacing the fabG gene with E. cloacae speC1. After adaptive evolution with C. glutamicum PUT4, the evolved strain C. glutamicum PUT-ALE, which produced an 96% higher amount of putrescine compared to the parent strain, was obtained. The whole genome resequencing indicates that the SNPs located in the odhA coding region may be associated with putrescine production. The comparative proteomic analysis reveals that the pentose phosphate and anaplerotic pathway, the glyoxylate cycle, and the ornithine biosynthetic pathway were upregulated in the evolved strain C. glutamicum PUT-ALE. The aspartate family, aromatic, and branched chain amino acid and fatty acid biosynthetic pathways were also observed to be downregulated in C. glutamicum PUT-ALE. Reducing OdhA activity by replacing the odhA native start codon GTG with TTG and overexpression of cgmA or pyc458 further improved putrescine production. Repressing the carB, ilvH, ilvB and aroE expression via CRISPRi also increased putrescine production by 5, 9, 16 and 19%, respectively.
Publication
Journal: Cancer Chemotherapy and Pharmacology
December/16/2015
Abstract
OBJECTIVE
To assess the link between tumor growth inhibition (TGI) and overall survival (OS) based on historical renal cell carcinoma (RCC) data. To illustrate how simulations can help to identify TGI thresholds based on target OS benefit [i.e., hazard ratio (HR) compared with standard of care] to support new drug development in RCC.
METHODS
Tumor size (TS) data were modeled from 2552 patients with first-line or refractory RCC who received temsirolimus, interferon, sunitinib, sorafenib or axitinib in 10 Phase II or Phase III studies. Three model-based TGI metrics estimates [early tumor shrinkage (ETS) at week 8, 10 or 12, time to tumor growth (TTG) and growth rate] as well as baseline prognostic factors were tested in multivariate lognormal models of OS. Model performance was evaluated by posterior predictive check of the OS distributions and hazard ratio across treatments.
RESULTS
TTG was the best TGI metric to predict OS. However, week 8 ETS had a satisfactory performance and was employed in order to maximize clinical utilization. The week 8 ETS to OS model was then used to simulate clinically relevant ETS thresholds for future Phase II studies with investigational treatments.
CONCLUSIONS
The published OS model and resultant simulations can be leveraged to support Phase II design and predict expected OS and HR (based on early observed TGI data obtained in Phase II or Phase III studies), thereby informing important mRCC development decisions, e.g., Go/No Go and dose regimen selection.
Publication
Journal: Jornal de Pediatria
May/6/2013
Abstract
OBJECTIVE
To determine the prevalence of celiac disease in patients with myocarditis and dilated cardiomyopathy.
METHODS
Fifty-six patients between 1 and 18 years old with dilated cardiomyopathy or myocarditis were evaluated and followed up at Instituto de Medicina Integral Professor Fernando Figueira. Patients with previous diagnosis of celiac disease were excluded. The functional classification was determined according to the American Heart Association criteria (classes I, II, III and IV). Diagnosis of myocarditis was reported in the patients' medical records. Dilated cardiomyopathy was diagnosed by echocardiogram with systolic dysfunction of one or both ventricles, ejection fraction lower than 55%, ventricular dilatation, and left ventricular diastolic diameter bigger than 112%. Patients answered a questionnaire about gastrointestinal and cardiac symptoms; next, anti-tissue transglutaminase (tTG) and anti-endomysial (EMA) antibodies were dosed. Those with positive antibody results were referred to intestinal biopsy and histological evaluation to detect celiac disease according to Marsh classification.
RESULTS
One of the 56 children (1.8%) had positive tTG antibody level, but negative EMA. Intestinal histological evaluation showed total villous atrophy. Approximately, 30% of patients had heart failure. Gastrointestinal symptoms and signs were frequent, especially abdominal pain (70%, 39/56).
CONCLUSIONS
Celiac disease prevalence in pediatric patients with dilated cardiomyopathy or myocarditis was 1.8%. It is important to investigate celiac disease in patients with these conditions to avoid the progression of such diseases and patients' clinical deterioration.
Publication
Journal: Nutrients
May/2/2016
Abstract
HLA-linked genes are relevant to celiac disease (CD); the potential genetic differences present worldwide are not fully understood. Previous results suggest that the distribution of HLA-DQ2/DQ7/DQ8 in Chile may differ from that in Europe and North America. In celiac patients and their first-degree relatives (FDRS), we assessed their clinical, serological and histological characteristics, determined HLA-DQ2, HLA-DQ7 and HLA-DQ8 alleles and genotypes, and evaluated the relations between them. A total of 222 individuals were assessed (56 cases, 166 FDRs). 16.9% of FDRs were tTG positive; 53.6% of them showed overweight/obesity and 3% undernourishment; they spontaneously declared being asymptomatic, but detailed questioning revealed that 60.7% experienced symptoms, which had not been investigated. DQ2 was present in 53.9% and 43.9.0% of cases and FDRs (p < 0.05). The most frequent genotype distribution was DQ2/DQ7 (fr 0.392 (cases) and 0.248 (FDRs), respectively, p < 0.02). The next most common genotypes were HLA-DQ2/DQ8 (fr 0.236 in FDRs and 0.176 in cases, p < 0.05). 3.92% cases were not HLA-DQ2/DQ8 carriers. Among tTG positive FDRs, 57.4%, 22.3% and 20.2% carried DQ2, DQ7 and DQ8, respectively. In cases, 72.7% of the biopsies classified Marsh ≥ 3 carried at least one DQ2; 91.7% of DQ2/DQ2 and 88.3% of DQ2/DQ7 were Marsh ≥ 3. Thus, DQ2 frequency is lower than reported; the higher frequency found for DQ8 and DQ7 concur with recent publications from Argentine and Brazil. These results suggest that although CD may manifest clinically in ways similar to those described in other populations, some genetic peculiarities in this region deserve further study.
Publication
Journal: Middle East Journal of Digestive Diseases
August/4/2014
Abstract
BACKGROUND Recent guidelines have proposed that there is a correlation between tissue transglutaminase (tTG) antibody titers and degrees of duodenal biopsy, and that duodenal biopsy can be omitted in some patients with high levels of tTG antibody. Using data of registered patients in a gastrointestinal clinic we aimed to assess the correlation between tissue transglutaminase antibody with duodenal histologic Marsh grading in Iranian patients with celiac disease. METHODS We retrospectively reviewed hospital files of registered patients in the gastrointestinal clinic of Firoozgar Hospital, Tehran, Iran. Demographic, laboratory, and histology data of those who had tTG titer and pathology reports of duodenal biopsy based on the modified Marsh classification were extracted and used for the study. RESULTS 159 patients with available tTG titer and pathology reports were enrolled in our study. Mean ±SD of the patients was 35.6±15.2 and 100 (62.9%) of them were women. 133 out of 153 patients had villous atrophy (Marsh IIIa-IIIc). Anemia was the most common sign and bloating, abdominal pain, and diarrhea were the first three common symptoms in these patients. Mean tTG titers was significantly higher in patients graded as Marsh III (p for trend=0.003). Our results showed that tTG titer more than 9 folds higher than the kit's cut-off value was about 97.2% sensitive for Marsh II and more duodenal damage. CONCLUSION There was a correlation between tTG titers and degrees of duodenal damage in patients with celiac disease. Duodenal biopsy is not always necessary for diagnosing celiac disease and when tTG level is more than 9 folds higher than the manufacture's recommended cut-off value it can be avoided. Meanwhile small intestinal biopsy should always be considered in case of high clinical suspicion, regardless of the results of serologic testing.
Publication
Journal: World Journal of Gastroenterology
September/2/2015
Abstract
OBJECTIVE
To investigate the densities of dendritic cells (DCs) and FOXP3(+) regulatory T cells (Tregs) and their interrelations in the small bowel mucosa in untreated celiac disease (CD) patients with and without type 1 diabetes (T1D).
METHODS
Seventy-four patients (45 female, 29 male, mean age 11.1 ± 6.8 years) who underwent small bowel biopsy were studied. CD without T1D was diagnosed in 18 patients, and CD with T1D was diagnosed in 15 patients. Normal small bowel mucosa was found in two T1D patients. Thirty-nine patients (mean age 12.8 ± 4.9 years) with other diagnoses (functional dyspepsia, duodenal ulcer, erosive gastritis, etc.) formed the control group. All CD patients had partial or subtotal villous atrophy according to the Marsh classification: Marsh grade IIIa in 9, grade IIIb in 21 and grade IIIc in 3 cases. Thirty-nine patients without CD and 2 with T1D had normal small bowel mucosa (Marsh grade 0). The densities of CD11c(+), IDO(+), CD103(+), Langerin (CD207(+)) DCs and FOXP3(+) Tregs were investigated by immunohistochemistry (on paraffin-embedded specimens) and immunofluorescence (on cryostat sections) methods using a combination of mono- and double-staining. Sixty-six serum samples were tested for IgA-tissue transglutaminase (tTG) using a fully automated EliA™ Celikey(®) IgA assay (Pharmacia Diagnostics, Freiburg, Germany).
RESULTS
The density of CD11c(+) DCs was significantly increased in CD patients compared with patients with normal mucosa (21.67 ± 2.49 vs 13.58 ± 1.51, P = 0.007). The numbers of FOXP3(+) cells were significantly higher in CD patients (10.66 ± 1.50 vs 1.92 ± 0.37, P = 0.0002) and in patients with CD and coexisting T1D (8.11 ± 1.64 vs 1.92 ± 0.37, P = 0.002) compared with patients with normal mucosa. The density of FOXP3(+) cells significantly correlated with the histological grade of atrophic changes in the small bowel mucosa according to the March classification (r = 0.62; P < 0.0001) and with levels of IgA antibody (r = 0.55; P < 0.0001). The densities of IDO(+) DCs were significantly higher in CD patients (21.6 ± 2.67 vs 6.26 ± 0.84, P = 0.00003) and in patients with CD and coexisting T1D (19.08 ± 3.61 vs 6.26 ± 0.84, P = 0.004) compared with patients with normal mucosa. A significant correlation was identified between the densities of IDO(+) DCs and FOXP3(+) T cells (r = 0.76; P = 0.0001). The mean values of CD103(+) DCs were significantly higher in CD patients (10.66 ± 1.53 vs 6.34 ± 0.61, P = 0.01) and in patients with CD and associated T1D (11.13 ± 0.72 vs 6.34 ± 0.61, P = 0.00002) compared with subjects with normal small bowel mucosa. The mean value of Langerin(+) DCs was higher in CD patients compared with persons with normal mucosa (7.4 ± 0.92 vs 5.64 ± 0.46, P = 0.04).
CONCLUSIONS
The participation of diverse DC subsets in the pathological processes of CD and the possible involvement of tolerogenic DCs in Tregs development to maintain intestinal immunological tolerance in CD patients are revealed.
Publication
Journal: Arab Journal of Gastroenterology
December/4/2011
Abstract
OBJECTIVE
High prevalence rates of coeliac disease (CD) in patients with type 1 diabetes mellitus (T1DM) have been reported. The aim of this study was to evaluate the frequency of silent CD in a sample of Iraqi patients with T1DM.
METHODS
This is a cross-sectional study done in Baghdad Teaching Hospital, Baghdad Medical City, Baghdad, Iraq, on 62 patients with T1DM. For all patients, immunoglobulin A (IgA) anti-tissue transglutaminase antibodies (IgA tTG), IgG anti-tissue transglutaminase antibodies (IgG tTG), IgA endomysial antibody (IgA EMA), IgA antigliadin antibodies (IgA AGA) and IgG antigliadin antibodies (IgG AGA) tests were done, with duodenoscopy, and at least four biopsies were taken from the second part of the duodenum.
RESULTS
A total of 27 patients (43.5%) had normal small-intestinal histopathology (Marsh 0), one of them had a positive result for all serological markers used in the study, and another patient was positive for IgA tTG only. Ten patients (16.1%) had Marsh grade I, one of them was positive for IgA tTG, IgG tTG and IgA EMA, another patient was IgA deficient and had positive IgG tTG only and another patient with Marsh I had positive IgA tTG and IgG tTG only. Two patients (3.2%) had Marsh IIIA; three patients (4.8%) had Marsh IIIB histopathology, two of them were positive for all tests and one had positive IgA tTG and IgA EMA only. Two patients (3.2%) had Marsh IIIC histopathological features; they were positive for all serological tests, hence, the frequency of CD was 11.2%.
CONCLUSIONS
The frequency of silent CD in Iraqi patients with T1DM is not rare, reaching up to 11.2%. Both EMA and tTG antibodies are useful as screening tests.
Publication
Journal: Mitochondrial DNA Part A: DNA Mapping, Sequencing, and Analysis
September/17/2016
Abstract
The complete mitochondrial genome (mitogenome) of Poratrioza sinica (Hemiptera: Psyllidae) has been sequenced and annotated in this study. This mitogenome is 14,863 bp in length with an A + T content of 72.0%, and contains 37 typical animal mitochondrial genes that are arranged in the same order as that of the putative ancestral insect mitogenome. All protein-coding genes start with ATN codons except for nad5, which uses TTG as the initial codon. All the transfer RNA genes have the typical cloverleaf structure, except for trnS1 (AGN) which lacks the dihydrouridine (DHU) arm. The control region is 700 bp in length with 82.4% A + T content. This is the second completely sequenced mitogenome from the family Psyllidae of Hemiptera.
Publication
Journal: Applied Microbiology and Biotechnology
February/10/2002
Abstract
Glutamate dehydrogenase (GDH) was purified and characterized from an aerobic hyperthermophilic archaeon Aeropyrum pernix (A. pernix) K1. The enzyme has a hexameric structure with a native molecular mass of about 285 +/- 15 kDa. It was specific for NADP and thermostable (74% activity was remained after 5 h incubation at 100 degrees C). The activity of the enzyme increased in the presence of polar water-miscible organic solvents such as acetonitrile, methanol, and ethanol. The N-terminal sequence of GDH is Met-Gln-Pro-Thr-Asp-Pro-Leu-Glu-Glu-Ala. This sequence, except for the methionine, corresponds to amino acids 7-15 of the open reading frame (ORF) encoding the predicted GDH (ORF APE 1386). In the ORF nucleotide sequence, the codon TTG appears at the position of the methionine, suggesting that the leucine codon might be recognized as an initiation codon and translated to methionine in A. pernix GDH.
Publication
Journal: Clinica Chimica Acta
May/30/2013
Abstract
BACKGROUND
The deamidated gliadin peptides (DGP) cross linked to human tissue transglutaminase (tTg) comprises a novel neo-epitope structure (Neo-tTg) for serological screening of celiac disease (CD). Our aim is to verify anti-Neo-tTg IgA and IgG in adults with dermatitis herpetiformis (DH).
METHODS
Multi-centric retrospective evaluation of the IgA/G autoantibodies in sera of DH patients on a regular diet (n=40) and a gluten restricted diet (GRD, n=53) and control adults with autoimmune skin diseases (n=107) by ELISA.
RESULTS
The sensitivities of Celicheck Neo IgA/G (76%, 95% CI 67-84%) and the Neo tTg-A (85%, 95% CI 70-97%) ELISA were significantly greater than that of tTg-A (56%, 95% CI 46-67%), eTg-A (62%, 95% CI 52-72%), DGP-A (55%, 95% CI 55-65%), DGP-G (61%, 95% CI 51-71%), Glia-A (55%, 95% CI 45-65%) and Glia-G (56%, 95% CI 46-66%) ELISA. The specificities of all 8 ELISA were in the range of 90-100%. The area under the curve (AUC) of receiver operator characteristic curve (ROC) for the two Neo-tTg ELISA (0.863 and 0.949) were higher than the AUCs for ROCs of tTg, DGP and eTG ELISA (range between 0.657 and 0.783). The autoantibody levels of DH patients on a normal diet were significantly higher than those on GRD in the Celicheck Neo IgA/IgG, NeotTg-A; tTg-A and the eTg-A; ELISA (p<0.01) and of no significance in the DGP and Gliadin ELISA.
CONCLUSIONS
Neo-epitope IgA autoantibodies represent a new and sensitive serological marker of DH.
Publication
Journal: Journal of Medical Microbiology
March/2/1989
Abstract
A coagglutination test was developed for identifying suspected colonies of Vibrio cholerae serotype O1 directly from primary isolation plates. Visible agglutination occurs when V. cholerae O1 antibody attached to cell-wall protein A of Staphylococcus aureus reacts with its homologous antigen. From 314 faecal samples from clinically suspected cases of cholera, 210 colonies from thiosulphate citrate bile salts sucrose (TCBS) agar and 222 colonies from taurocholate tellurite gelatin (TTG) agar were tested as suspect V. cholerae. In each case 204 isolates were identified as V. cholerae O1 by conventional methods and also gave positive results for V. cholerae O1 in the coagglutination test; with one partial exception, no other colonies tested gave positive results. The coagglutination test is simple and inexpensive and provides a result 24 h earlier than conventional methods.
Publication
Journal: Journal of Pediatric Gastroenterology and Nutrition
December/8/2011
Abstract
OBJECTIVE
The aim of this study was to evaluate the value of HLA-DQ2/DQ8 allelic genotyping combined with serologic testing for the diagnosis of celiac disease (CD).
METHODS
One hundred seventy children, who underwent jejunal biopsy for digestive symptoms or malnutrition, were tested for HLA-DQ2/DQ8 and serologic markers (tTG and/or anti-endomysial antibodies). Children were classified in 2 groups, according to jejunal histology: group 1, when partial or total villous atrophy was associated with an increased intraepithelial lymphocytosis suggesting CD, and group 2, when these histological criteria were absent.
RESULTS
Eight children were excluded from the study because their intestinal histology was not informative; 82 children were classified in group 1 and 80 in group 2. Eighty-one of 82 children in group 1 were positive for HLA and serologic testing. The other child had negative HLA and serologic testing but marked villous atrophy, and further investigation showed an allergic disease. Among the 80 children in group 2, 53 were negative for both HLA and serologic testing, 22 were positive for HLA but negative for serologic testing, 2 were negative for HLA and positive for serologic testing, and 3 patients were positive for both HLA and serologic testing. The last 3 children were shown to have an autoimmune background and had probably a latent form of CD. The association of HLA-DQ2/DQ8 and serologic markers had a sensitivity of 98.8%, a specificity of 96.2%, a positive likelihood ratio of 26.3, and a negative likelihood ratio of 0.013.
CONCLUSIONS
The association of positive HLA-DQ2/DQ8 and serologic testing has a high predictive value for CD. We suggest that symptomatic children with high titers of immunoglobulin (Ig)A tTG could be diagnosed as patients with CD without performing jejunal biopsy. In other children, HLA-DQ2/DQ8 could be useful to exclude the diagnosis of CD if negative. In cases of low IgA tTG titers or in patients with IgA deficiency, intestinal biopsy remains mandatory.
Publication
Journal: Annals of Neurology
June/2/1997
Abstract
Progressive proximal muscle weakness is present both in spinal muscular atrophy (SMA) type III (Kugelberg-Welander disease) and in GM2 gangliosidosis, diseases that segregate in an autosomal recessive fashion. The SMN gene for SMA and the HEXA gene for GM2 gangliosidosis were investigated in a woman with progressive proximal muscle weakness, long believed to be SMA type III (Kugelberg-Welander type). She and her family underwent biochemical studies for GM2 gangliosidosis. Analysis of SMN excluded SMA. Biochemical studies on GM2 gangliosidosis showed deficiency in hexosaminidase A activity and increased GM2 ganglioside accumulation in the patient's fibroblasts. The HEXA gene was first analyzed for the Gly269->>Ser mutation characteristic for adult GM2 gangliosidosis. Since the patient was carrying the adult mutation heterozygously, all 14 exons and adjacent intron sequences were analyzed. A novel mutation in exon 1 resulting in an A-to-T change in the initiation codon (ATG to TTG) was identified. The adult patient is a compound heterozygote, with each allele containing a different mutation. Although mRNA was transcribed from the novel mutant allele, expression experiments showed no enzyme activity, suggesting that neither the TTG nor an alternative codon serve as an initiation codon in the HEXA gene.
Publication
Journal: Clinical Nephrology
September/23/2008
Abstract
OBJECTIVE
Better understanding of early onset of interstitial fibrosis and tubular atrophy (IF/TA), as the morphological surrogate of renal allograft deterioration might improve outcome after renal transplantation.
METHODS
We quantified mRNA expression of 3 profibrotic (transforming growth factor-beta (TGF-beta), tissue transglutaminase (tTG), tissue inhibitor of matrix metalloproteases (TIMP-1)) and 1 antifibrotic (matrix metalloprotease-2 (MMP-2)) molecule in protocol biopsies from renal allografts. From 107 transplants, two sequential protocol biopsies (6 weeks and 6 months) were analyzed. We evaluated a control group showing no IF/TA in both biopsies (n = 65) and a IF/TA group developing IF/TA at 6 months (n = 42). Expression data were correlated with clinical and histological risk factors for IF/TA and allograft function.
RESULTS
The expression of the genes correlated strongly with each other, particularly the profibrotic genes and in patients who developed IF/TA. Analyzing protocol biopsies from stable grafts, not all patients in both groups showed increased gene expression. In patients with increased gene expression a significantly higher tTG expression (matrix stabilization) at 6 weeks and a significantly lower MMP-2 expression (failure in matrix degradation) at 6 months were observed in the IFTA group compared to controls. Multivariate logistic regression revealed donor age positively and TIMP-1 expression at 6 weeks inversely correlated with IF/TA at 6 months.
CONCLUSIONS
We conclude that a disturbance in the equilibrium of pro- and antifibrotic pathways is decisive for early onset of IF/TA in renal allografts: insufficient degradation of exaggerated matrix production apparently changes the balance in the direction of IF/TA.
Publication
Journal: Journal of Pediatric Gastroenterology and Nutrition
July/22/2009
Abstract
OBJECTIVE
False-positive results of anti-tissue-transglutaminase (tTG) IgA autoantibodies have been reported in subjects with a genetic risk for celiac disease (CD). The aims of this retrospective study were to assess the prevalence of false-positive tTG titers in patients at risk of CD compared with symptomatic children and to evaluate the influence of age and indication for testing on tTG titers.
METHODS
All tTG results measured in our institution during a 33-month period were evaluated. Patients with known CD were excluded. Indications for testing were either symptoms suggestive of CD (group 1) or history of being at risk for CD (group 2). Duodenal biopsies were recommended if titers were positive >> or =10 U/mL) and offered if borderline >> or =4 to <10 U/mL).
RESULTS
The final analysis included 2056 patients, 1707 belonged to group 1, and 349 to group 2. All 65 patients with positive tTG results underwent biopsy (group 1: 57, group 2: 8). Celiac disease was confirmed in 61 subjects (median titer: 107.8 U/mL, range 12.0-1748 mL, NS between group 1 and 2), whereas 4 had normal histology (10.2-25.2 U/mL). Three out of 16 patients with borderline results underwent biopsy and had normal histology. Borderline titers were more common in group 2 patients (2.6% vs 0.4%, P<0.001). Multiple regression analysis in patients with negative tTG results (n=1975) revealed that titers were independently related to age (P<0.05) and indication for testing (P<0.001).
CONCLUSIONS
The influence of age and genetic predisposition/risk has to be taken into account when interpreting tTG results.
Publication
Journal: World Journal of Microbiology and Biotechnology
September/12/2013
Abstract
Lactic acid bacteria (LAB) are responsible for olfactory changes in wine during malolactic fermentation (MLF). A side characteristic of MLF is the release of grape derived aroma compounds from their glycosylated precursors by β-glycosidase activities of these bacteria. Apart from Oenococcus oeni, which is regarded as the most promising species for MLF, glycosidic activities have also been observed in wine related members of the genera Lactobacillus and Pediococcus. Nevertheless, information on the involved enzymes including their potential use in winemaking is limited. In this study we report that β-glucosidases with similar protein sequences can be identified in the genomes of Lactobacillus brevis, O. oeni and Leuconostoc mesenteroides. TTG serves as start codon for the glucosidase gene of O. oeni. The β-glucosidase of O. oeni ATCC BAA-1163 was expressed in E. coli and partially characterized. The enzyme displayed characteristics similar to β-glucosidases isolated from L. brevis and L. mesenteroides. A pH optimum between 5.0 and 5.5, and a K(m) of 0.17 mmol L(-1 )pNP-β-D-glucopyranoside were determined. A glycosyltransferase activity was observed in the presence of ethanol. The enzyme from O. oeni was capable to hydrolyze glycosides extracted from Muskat wine. This study also contains a report on glycosidase activities of several LAB species including Oenococcus kitaharae.
Publication
Journal: Progress in Clinical and Biological Research
March/29/1994
Abstract
The evidence presented here strengthens the argument that RA-induced truncation defects of the embryonic limb, and probably other teratogenic effects, are mediated by the nuclear retinoid receptors, particularly the RAR-beta 2 isoform. Although apoptotic cell death and an increased transglutaminase (tTG) activity accompany teratogenesis, it should be emphasized that the increased levels of RAR-beta 2 may influence additional events in limb development, e.g., modulation of connective tissue differentiation and an inhibition of chondrogenesis. Further work entails screening the effects of RA on genes targeted by the receptors.
Publication
Journal: FEBS Letters
September/10/1997
Abstract
Aging is accompanied by troubles resulting from changes in hormonal and nutritional status. Therefore, the abundance of mRNA coding for triiodothyronine (TR) and retinoic acid (RA) nuclear receptors was studied in the brain of young, adult and aged (2.5, 6 and 24 months, respectively) rats. In the brain of aged rats, there was a lower abundance of TR and RAR mRNA and a lower activity of tissue transglutaminase (tTG), an enzyme the gene of which is a target for retinoids. Administration of RA in these rats restored TR and RAR mRNA and the activity of tTG in the brain. The importance of these observations to the function of the aged brain is discussed.
Publication
Journal: Italian Journal of Pediatrics
October/27/2010
Abstract
BACKGROUND
Celiac disease (CD) emerged as a public health problem, and the disease prevalence varies among different races. The present study was designed to investigate the prevalence of CD using serological markers in apparently healthy schoolchildren in Irbid City, Jordan. Additionally, the effect of positive serology on height, weight and body mass index (BMI) was evaluated.
METHODS
The study population consisted of 1985 children (1117 girls and 868 boys), age range was 5.5 to 9.5 years. Height and weight were measured and blood samples were collected from each individual. Serum samples were analyzed for IgA anti-tissue transglutaminase antibodies (tTG) using a commercial enzyme-linked immunosorbent assay (ELISA). tTG positive samples were further analyzed for IgA anti-endomysium antibodies (EmA) with a commercial ELISA. Samples confirmed positive with EmA were considered seropositive.
RESULTS
Sixteen children were CD positive. The serological prevalence was estimated to be 1:124 (0.8%; 95% CI, 0.5% to 1.3%). Significant impact on growth (height) was found in seropositive children. When both sexes were individually analyzed, only boys showed height reduction. Furthermore, seropositive boys also had a significant weight reduction.
CONCLUSIONS
This study demonstrated that CD is prevalent among schoolchildren in Jordan. The seropositive children tend to have lower height, weight, and BMI than the seronegative group. These differences were significant only for boys. None of the participants is known to have CD prior to the study.
Publication
Journal: Journal of Bacteriology
February/27/1997
Abstract
Colicin V (ColV), an antibacterial peptide toxin, uses a dedicated signal sequence-independent export system for its extracellular secretion in Escherichia coli. The products of at least three genes (a chromosomal tolC gene and two plasmid-born cvaA and cvaB genes) are involved in this process. To characterize the gene products, the cvaA gene was subcloned and expressed under the control of T7 RNA polymerase promoter. Two in-frame proteins, CvaA and CvaA*, were expressed and identified. DNA sequences predicted that both proteins have two potential translational initiation sites. N-terminal peptide sequencing showed that the translation of CvaA starts from a TTG, 11 amino acids upstream of the previously proposed ATG initiation site. CvaA* is translated from an upstream ATG. Expression of both CvaA and CvaA* was induced by the iron chelator 2,2'-dipyridyl, indicating that cvaA is negatively regulated at least partially by Fur. CvaA*-depleted cells were found to secrete less ColV, based on reduced activity in the supernatant, than did wild type, which was recovered by the addition of a plasmid producing CvaA*. Interestingly, CvaA*-depleted and wild-type cells had similar levels of intracellular ColV activity. Translational fusions showed that the syntheses of ColV and CvaA are not affected by CvaA* depletion. However, CvaA in CvaA*-depleted cells was less stable than that in wild-type cells, indicating that CvaA* may directly or indirectly affect the stability of CvaA. We conclude that CvaA* is not essential for ColV secretion but that it enhances the ColV secretion by stabilizing the CvaA protein.
Publication
Journal: Journal of Molecular Modeling
August/6/2007
Abstract
The dynamic structure of 11-mer DNA duplexes of different sequences with or without homopyrimidine (T.T, or BrdU.T) mismatches was studied by molecular dynamics (MD) simulations on a time scale from 200 ps to 1 ns. The conformational analysis suggests that in mismatched duplexes the formation of classical T.T wobble H-bonding pairing is nearest-neighbor sequence-dependent and, in most cases, three-centered H-bonds and numerous alternative close cross-strand interatomic contacts exist. Thus, in duplex W1, where the central triplet is 5'd(CTA).d(TTG), two wobble conformations W upward arrow (alphabeta) and W downward arrow (betaalpha) are formed and exchange rapidly at 300 K. In contrast, when the central triplet is 5'd(TTT).d(ATA) (W2 duplex) wobble conformations are rarely observed at 300 K, and the T.T mispair most often adopts a "twisted" conformation with one largely persistent normal H-bond, plus a stable cross-strand contact involving a T flanking base. However, at elevated temperature (400 K) the same W2 duplex shows frequent exchange between the two classical wobble conformations (alphabeta<->>betaalpha), as is in the case when the central triplet is 5'd(TBrdUT).d(ATA) (W3 duplex at 300 K). It is suggested that in the W2 sequence, restrictions due to thymine-methyl/pi interactions prevent the formation of wobble pairing and thermal activation energy, and/or the chemical replacement of T by BrdU are required in order for the T(BrdU).T mismatch to adopt and exchange between wobble conformations. The specific short and/or long-lived (double/triple) cross-strand dynamic interactions in W1, W2 and W3 duplexes are throughout characterized. These frequent atomic encounters exemplify possible inter-strand charge transfer pathways in the studied DNA molecules.
Publication
Journal: Human Antibodies
September/12/2001
Abstract
Celiac disease (CD) is an autoimmune enteropathy characterized by intestinal malabsorption and immunological responses to dietary gliadins and an auto antigen located in the endomysium. The latter has recently been identified as the enzyme tissue transglutaminase (tTG). The linkage between gliadins, tTG and the autoimmune response has still to be clarified. In this work we report the production and analysis of a phage antibody library from the peripheral blood lymphocytes (PLB) of a CD patient. The library contained polyreactive and monoreactive antibodies to alpha-gliadin, to the dietary antigen beta-lactoglobulin, but not to tTG. The majority of the VH regions of the anti-alpha-gliadin antibodies belonged to the VH 4 family. The possibility of exploiting phage display antibodies as tools to study the molecular events associated with CD is discussed.
load more...