Biomedical subjects

M Nagy

Publications and source records attributed to M Nagy.

At least 37 records · Page 2Linked to original sources

PubMed2001

Phenolic acids reduce the genotoxicity of acridine orange and ofloxacin in Salmonella typhimurium.

Naturally occurring plant phenolics, p-coumaric acid (PA), caffeic acid (CA), ferulic acid (FA) and gentisic acid (GA) (25-100 nmol/L) had protective effects on acridine orange (AO; 216 mumol/L)- and ofloxacin (3 mumol/L)-induced genotoxicity in Salmonella typhimurium. FA, GA and CA exhibited a significant concentration-dependent protective effect against the genotoxicity of AO and ofloxacin, with the exception of PA, which at all concentrations tested abolished the AO and ofloxacin genotoxicity. UV spectrophotometric measurements showed the interaction of PA, FA, GA and CA with AO but not with ofloxacin; this interaction is obviously responsible for the reduction of AO-induced S. typhimurium mutagenicity. In the case of ofloxacin the antimutagenic effect of PA, FA, GA and CA is assumed to be a result of their ability to scavenge reactive oxygen species (ROS) produced by ofloxacin.

Acridine Orange↗

PubMed2001

Refinement of the chromosome 5p locus for craniometaphyseal dysplasia.

Craniometaphyseal dysplasia--Jackson type (CMDJ) is an autosomal dominant bone dysplasia with hyperostosis and sclerosis of the skull and abnormal modelling of the metaphyses. In a large German pedigree, a locus for CMDJ has been mapped previously to the short arm of chromosome 5 (5p15.2-p14.1), defining a 19-cM disease interval between markers D5S2004 and D5S502. Analysis of a large Australian pedigree together with a second German family confirms linkage to the same region. Obligate recombinations in the new families and confirmation of a supposed recombination in the previously reported German kindred have enabled us to narrow the critical region down to approximately 4 cM between markers D5S1987 and D5S1991.

Australia↗

PubMed2001

Alterations on the 5' noncoding region of the BCL-6 gene are not correlated with BCL-6 protein expression in T cell non-Hodgkin lymphomas.

The BCL-6 proto-oncogene is expressed in germinal center B lymphocytes, in their neoplastic counterparts, and in a subpopulation of germinal center and perifollicular T lymphocytes. Rearrangements and/or mutations of the 5' noncoding region of the bcl-6 gene have been demonstrated in a large majority of diffuse large B cell lymphomas. Some, but not all, of these genetic alterations lead to dysregulation of the protein. Recently, anaplastic large cell lymphomas with T and null cell phenotypes, as well as T lymphoblastic lymphomas, have also been reported to exhibit immunoreactivity to the anti-BCL-6 antibody. We collected 33 T cell non-Hodgkin lymphomas (T-NHLs) and analyzed their expression of the BCL-6 protein by immunohistochemistry and investigated the organization of the bcl-6 gene by Southern blot and single strand conformation polymorphism (SSCP). The expression of BCL-6 was demonstrated in 37.5% of lymphoblastic (LBL), 40% of anaplastic large cell (ALCL), and 33% of peripheral T cell lymphomas (PTCL). BCL-6-positive malignant cells exhibited the CD4+ or CD4+/CD8+ phenotype. The bcl-6 gene was in a germline configuration in all T-NHLs examined, and a mutation at the first exon-intron boundary region structure of the wild-type bcl-6 gene was detected in 3 of 12 PTCL. One case of PTCL with mutations of the 5' noncoding region expressed BCL-6. In conclusion, expression of the BCL-6 protein is demonstrable independently of bcl-6 alterations in T-NHLs. This further suggests that molecular mechanisms other than rearrangements and/or mutations of the 5' noncoding region of the bcl-6 gene can result in expression of the protein. Whether these lymphomas arose from T cells expressing BCL-6 or expressed BCL-6 as part of the malignant transformation process needs to be determined. Finally, structural alterations of bcl-6 are rare in T-NHLs, but mutations do occur in the 5' noncoding region. We suggest that expression of BCL-6 in T cells may facilitate lymphomagenesis by repressing critical cytokines and cell cycle regulators.

Blotting, Southern↗

PubMed2001

Gluteal necrotizing myofascitis: an unusual delayed complication of abdominal sacrocolpopexy.

Persistent low back pain developed in a 51-year-old woman after she had undergone abdominal sacrocolpopexy. Four months postoperatively, necrotizing myofascitis developed in her gluteal muscles. The infected mesh, which had eroded into the vagina, was removed. Cultures of the infected mesh and abscesses grew common vaginal flora, including Gardnerella vaginalis and Actinomyces.

Back Pain↗

PubMed2001

Effectiveness of adenoidectomy and laser tympanic membrane fenestration.

OBJECTIVE: Adenoidectomy alone or with tonsillectomy (A+/-T) is an effective surgical intervention in the management of otitis media in children, especially when it is performed in conjunction with insertion of pressure equalization tubes (PETs). Otorrhea and persistent tympanic membrane (TM) perforation are frequent complications. This study evaluates the effectiveness of intermediate duration middle ear ventilation using laser tympanic membrane fenestration (LTMF) without tube insertion and as an adjunct to adenoidectomy in resolving middle ear disease within the first 90 days after surgery. STUDY DESIGN: This pilot study was a multicenter, prospective clinical cohort trial. Institutional review board approval and informed consent were obtained. The study involved four tertiary care pediatric otolaryngology departments. Fifty children (96 ears) were treated with LTMF in conjunction with A+/-T from June 1, 1998, through March 30, 1999. Ages ranged from 9 months to 12 years. Patients undergoing A+/-T who would have been recommended for PET insertion instead underwent middle ear ventilation with LTMF using the Oto-LAM device (ESC/Sharplan, Yokneam, Israel). Patients were seen at 30, 60, and 90 days postoperatively. Resolution of otitis media with effusion was determined by clinical examination, which included pneumatic otoscopy, audiometry, and tympanometry. RESULTS: Of the treated ears, 88%, 86%, and 83% had clinical resolution of middle ear disease at 30, 60, and 90 days, respectively. Preoperatively, 45% (n = 85) of ears had normal hearing; 92% (n = 49) had normal hearing at 90 days. Eighty-nine percent (n = 92) had type C2 or B tympanograms preoperatively, and 12% (n = 60) had type C2 or B at 90 days. CONCLUSION: Laser tympanic membrane fenestration in conjunction with adenoidectomy was effective in restoring normal middle ear function at 90 days post-treatment in greater than 80% of children who otherwise may have had placement of PETs.

Adenoids↗

PubMed2001

[Nonpolar components of the leaves of Philadelphus coronarius L].

The paper deals with the isolation of constituents from light petrol and chloroform extracts of the leaves of Philadelphus coronarius L., Saxifragaceae. From the light petrol extract uvaol and 3 beta,28-dihydroxyoleanane-11(12),13(18)-diene were isolated, while coumarins (umbelliferone, scopolin), stigmasteryl-3 beta-D-glucoside and the alcane type carbohydrate-C29H60 were isolated from the chloroform extract. The isolated compounds were identified by spectroscopic means and by comparison with standards and the literature data.

Coumarins↗

PubMed2001

[Monodesmosidic saponins in Cynara cardunculus L].

From an ethanolic extract of the flower buds of Cynara cardunculus L. (Asteraceae), two monodesmosidic saponins, cynarasaponin B and a new cynarasaponin K, were isolated. The isolated compounds were identified by spectroscopic means and by comparison with standards and the literature data.

Asteraceae↗

PubMed2001

[Constituents of the leaves of Ligustrum delavayanum Hariot].

From the chloroform part of Ligustrum delavayanum Hariot, leaves five constituents were isolated: tyrosol, esculetine, kempferol-7-O-rhamnoside, quercetine-3-O-glucoside, and quercetine. Further six constituents (probably malvidine, two secoiridoid glycosides, caffeic acid monosaccharide ester, quercetine monoglycoside (no hyperoside), and quercetine diglycoside (no rutinoside)) were isolated from the methanolic part of above mentioned drug.

Flavonoids↗

PubMed2000

A new method for the evaluation of matches in non-recombining genomes: application to Y-chromosomal short tandem repeat (STR) haplotypes in European males.

A 9-locus microsatellite framework (minimal haplotype), previously developed for forensic purposes so as to facilitate stain analysis, personal identification and kinship testing, has been adopted for the establishment of a large reference database of male European Y-chromosomal haplotypes. The extent of population stratification pertaining to this database, an issue crucial for its practical forensic application, was assessed through analysis of molecular variance (AMOVA) of the 20 regional samples included. Despite the notion of some significant haplotype frequency differences, which were found to correlate with known demographic and historic features of Europeans, AMOVA generally revealed a high level of genetic homogeneity among the populations analyzed. Owing to their high diversity, however, accurate frequency estimation is difficult for Y-STR haplotypes when realistic (i.e. moderately sized) datasets are being used. As expected, strong pair-wise and higher order allelic associations were found to exist between all markers studied, implying that haplotype frequencies cannot be estimated as products of allele frequencies. A new extrapolation method was therefore developed which treats haplotype frequencies as random variables and generates estimates of the underlying distribution functions on the basis of closely related haplotypes. This approach, termed frequency 'surveying', is based upon standard population genetics theory and can in principle be applied to any combination of markers located on the Y-chromosome or in the mitochondrial genome. Application of the method to the quality assured reference Y-STR haplotype database described herein will prove very useful for the evaluation of positive trace-donor matches in forensic casework.

Alleles↗

PubMed2000

Characterization of reversed-phase columns using the linear free energy relationship. III. Effect of the organic modifier and the mobile phase composition.

Retention factors determined for 31 solutes of widely different types on five columns of different chromatographic characteristics have been used to calculate the regression coefficients of the linear free energy relationship (LFER) equations. The mobile phases investigated consisted of acetonitrile-water and methanol-water, respectively, in a composition range of 20-70% (v/v) of organic modifiers. The regression coefficients of the LFER equations are characteristic of the given phase system (stationary phase, organic modifier and mobile phase composition) and represent the extent of the various molecular interactions contributing to the retention process. The effect of the characteristic of the stationary phase, the type of the organic modifier and the mobile phase composition is demonstrated and discussed. Alpha selectivity factors have been determined for various pairs of compounds. Hydrophobic or methylene selectivity can be described by the variation of the upsilon coefficient in Eq. (3) representing the difference in hydrophobicity between the stationary phase and the mobile phase. The polar or chemical selectivity of a phase system varies with the b coefficient in Eq. (3) representing the difference in acidity between the stationary phase and the mobile phase. Polar selectivity, i.e. the relative retention of polar solutes to that of a non-polar solute, e.g. toluene decreases with increasing polarity of the mobile phase. It depends also significantly on the polar characteristics of the columns. Specific selectivity, i.e. the relative retention of various polar solutes depends on the acidic or basic properties of the solutes to be separated and the chemical properties of the columns. The b regression coefficients can be used to describe the effect of mobile phase composition on the variation of specific selectivities. We have demonstrated that the LFER method provides a useful estimate of selectivity under different operating conditions by using the solvation parameters describing the different molecular interactions and the regression coefficients of the LFER equation characterizing the phase system.

Chromatography, Liquid↗

PubMed2000

Phenolic acids inhibit chloroplast mutagenesis in Euglena gracilis.

The mutagenicity (bleaching activity) of ofloxacin (43 microM) and acridine orange (AO) (13.5 microM) in Euglena gracilis is inhibited by plant phenolics. Caffeic acid (CA), p-coumaric acid (PCA), ferulic acid (FA) and gentisic acid (GA) (25, 50, 100 and 250 microM) exhibited a significant concentration-dependent inhibitory effect against ofloxacin-induced mutagenicity, which was very effectively eliminated by the highest concentration of all four of those phenolic acids. The mutagenicity of AO was also significantly reduced in the presence of CA, PCA and FA (25, 50, 100 and 250 microM). However, GA exhibited no significant activity, even at the concentration of 250 microM. Based on the UV spectrophotometric measurements, we suggest that the antimutagenic effect of CA, PCA, FA and GA resulted from the scavenging of reactive oxygen species (ROS) produced by ofloxacin. On the other hand, the reduction of AO-induced mutagenicity correlates with the binding capabilities of CA, PCA and FA, with the exception of GA.

Acridine Orange↗

PubMed2000

Clinical presentation as a guide to the identification of GERD in children.

OBJECTIVE: to determine if there is a correlation between common otolaryngologic symptoms and presence of gastroesophageal reflux disease (GERD) in children. METHODS: charts of 295 children presenting with suspicion of GERD were reviewed for presenting symptoms including: (1) airway symptoms: stertor, stridor, frequent cough, recurrent croup, wheezing, nasal congestion, obstructive apnea, blue spells, hoarseness, throat clearing; (2) feeding symptoms: wet burps, globus sensation, frequent emesis, dysphagia, choking/gagging, sore throat, halitosis, food refusal, stomach aches, arching, drooling, chest pain, irritability, and failure to thrive. At least one positive test of barium esophagram, gastric scintiscan, pH probe or esophageal biopsy resulted in inclusion in the GERD positive group. RESULTS: 214 children had GERD diagnosed while 81 had no positive tests for GERD. Between the GERD positive and GERD negative groups, the significantly different symptoms were stertor (P=0.040), cyanotic spells (P=0.043), frequent emesis (P=0.007), failure to thrive (P=0.006), and choking/gagging (P=0.044). Three pooled variables were created: airway flow (stertor, stridor, cyanotic spells), airway irritation (frequent cough, recurrent croup, throat clearing), and feeding (dysphagia, failure to thrive, frequent emesis). GERD patients who were 2 years or less were compared to those older than 2 years and all three of these pooled variables were significantly different between these groups (P<0. 001). CONCLUSION: children who present with a certain constellation of airway or feeding symptoms are more likely to have a positive GERD test. Children 2 years old or less are more likely to present with airway symptoms or feeding difficulties while children older than 2 years are more likely to present with airway irritation.

Airway Obstruction↗

PubMed2000

[Detection of minimal residual diseases in B-cell tumors using PCR specific for the immunoglobulin heavy chain gene].

In B-cell non-Hodgkin's lymphomas (NHL), clonal rearrangement of the immunoglobulin heavy chain (IgH) gene provides a useful marker for the detection of minimal residual disease (MRD) after treatment. To explore clinical usefulness of polymerase chain reaction (PCR) analysis of clonal IgH gene rearrangement in the detection of MRD a follow up study of 10 patients with B-cell NHL have been performed. At the time of diagnosis, tumor DNAs were PCR-amplified using sense primer specific for the heavy chain variable region (VH) and antisense primer specific for the heavy chain joining region (JH) of the IgH gene. The clonal rearrangement of IgH gene detected by PCR was used as clonal marker to determine MRD after treatment. In three cases, where clinical remission was not achieved, clonal IgH gene rearrangement was detected after the treatment. In seven cases, clinical remission was achieved after induction therapy but the PCR analysis revealed clonal IgH gene rearrangement in three of the cases. In all of the three cases, where MRD was detected by PCR, clinical relapse developed after 7-28 months of the therapy. In all cases that have relapsed, the IgH gene rearrangement was identical at the time of initial diagnosis and at the relapse. This study demonstrates that PCR analysis of clonal IgH gene rearrangement is a useful method to monitor and detect MRD before clinical relapse.

Biomarkers, Tumor↗

PubMed2000

Characteristics and frequency of germline mutations at microsatellite loci from the human Y chromosome, as revealed by direct observation in father/son pairs.

A number of applications of analysis of human Y-chromosome microsatellite loci to human evolution and forensic science require reliable estimates of the mutation rate and knowledge of the mutational mechanism. We therefore screened a total of 4,999 meioses from father/son pairs with confirmed paternity (probability >/=99. 9%) at 15 Y-chromosomal microsatellite loci and identified 14 mutations. The locus-specific mutation-rate estimates were 0-8. 58x10-3, and the average mutation rate estimates were 3.17x10-3 (95% confidence interval [CI] 1.89-4.94x10-3) across 8 tetranucleotide microsatellites and 2.80x10-3 (95% CI 1.72-4.27x10-3) across all 15 Y-chromosomal microsatellites studied. Our data show a mutational bias toward length increase, on the basis of observation of more repeat gains than losses (10:4). The data are in almost complete agreement with the stepwise-mutation model, with 13 single-repeat changes and 1 double-repeat change. Sequence analysis revealed that all mutations occurred in uninterrupted homogenous arrays of >/=11 repeats. We conclude that mutation rates and characteristics of human Y-chromosomal microsatellites are consistent with those of autosomal microsatellites. This indicates that the general mutational mechanism of microsatellites is independent of recombination.

Adolescent↗

PubMed2000

Antibacterial activity of plant extracts from the families Fabaceae, Oleaceae, Philadelphaceae, Rosaceae and Staphyleaceae.

The selected plant extracts exhibited antibacterial activity. The strongest effect was manifested by extracts prepared from Gymnocladus dioicus, Amelanchier ovalis, Exochorda racemosa, Holodiscus discolor, Philadelphus microphyllus, Philadelphus coronarius and Pelargonium tabulare. The percentage inhibition of bacterial growth was 0-41.8%. In addition it was found that extracts isolated from Amelanchier ovalis, Exochorda racemosa and Pelargonium tabulare were specifically effective only against the bacterial strains tested.

Anti-Bacterial Agents↗

PubMed2000

Somatic mutation of the 5' noncoding region of the BCL-6 gene is associated with intraclonal diversity and clonal selection in histological transformation of follicular lymphoma.

Follicular lymphoma (FL) is a B cell non-Hodgkin's lymphoma (NHL) that frequently displays a t(14;18) translocation. Clonal evolution and histological transformation of FL is frequently associated with the accumulation of secondary genetic alterations. It has been demonstrated that the BCL-6 gene can be altered by chromosomal rearrangements and by mutations clustering in its 5' noncoding region in a significant fraction of FL and diffuse large cell lymphoma (DLCL). To elucidate the role of the BCL-6 gene alterations in the histological transformation and clonal progression of FL, we analyzed serial biopsy specimens from 12 patients with FL. Two cases of FL showed no histological alteration in the second biopsy, and 10 cases of FL showed morphological transformation to DLCL in the second biopsy. Southern blot analysis was used to detect rearrangement of the BCL-6 gene, polymerase chain reaction-single strand conformation polymorphism and sequence analysis were performed for identification of mutations in the 5' noncoding region of the BCL-6 gene, and immunohistochemical analysis was applied to reveal the BCL-6 protein expression. No BCL-6 gene rearrangement was detected in any of the samples, but a total of 58 mutations were found in the 5' noncoding region of the BCL-6 gene in seven cases. In five cases, both the FL and the clonally related FL or DLCL, and in two cases only the DLCL samples were mutated. The mutations were identical in multiple biopsy specimens of FL that did not show morphological transformation. In six patients where FL cells underwent morphological transformation, considerable intraclonal sequence heterogeneity was observed, indicating an ongoing type of somatic mutation. Based on the pattern of shared and nonshared mutations, the genealogical relationship of neoplastic clones could be established. In all of these cases, the histological transformation of FL was associated with the emergence of a subpopulation marked by new sites of mutations in the BCL-6 5' noncoding sequences. In three of these six cases, the histological transformation is also associated with the reduced expression of the BCL-6 protein. These findings demonstrate that mutation of the 5' noncoding region of the BCL-6 gene developed in the clonal evolution of FL, and at different time points in the lymphoma evolution different clonotypes dominate.

5' Untranslated Regions↗

PubMed2000

Immunoglobulin V(H) gene mutational analysis suggests that blastic variant of mantle cell lymphoma derives from different stages of B-cell maturation.

To characterise the nature of the cellular origin of the blastic variant of mantle cell lymphoma (MCL-BV), we analysed the immunoglobulin (Ig) heavy chain variable region (V(H)) genes in four cases of MCL-BV. The rearranged V(H)-D J(H) genes were PCR-amplified, cloned and sequenced. In one case, the comparison of the rearranged V(H) gene sequence to known germline V(H) gene templates showed no somatic mutations suggesting a pre-germinal centre B-cell origin for tumour cells. In the other three cases, the V(H) gene sequences showed varied number of point mutations relative to the putative germline V(H) gene sequences but the point mutations were not associated with intraclonal diversification. In one of the mutated cases, the distribution and type of the mutations indicated that tumour cells had been selected by an antigen. Since somatically mutated Ig genes are expressed by B-cells that have reached a germinal centre/post-germinal centre stage of development, these findings suggest that the MCL-BV cell of origin may also be a germinal centre or a post-germinal centre B-cell. Taken together, our findings suggest that the development of MCL-BC may not be restricted to one stage of B-cell differentiation and that they may represent transformants of B-cells at different stages of ontogeny.

Amino Acid Sequence↗

PubMed2000

Pattern of noncompliance with dialysis exchanges in peritoneal dialysis patients.

The purpose of the study is to evaluate the pattern of noncompliance in peritoneal dialysis (PD) patients using home visit supply inventories. Ninety-two patients were enrolled at the start of dialysis. Noncompliance, defined as performance of less than 90% of prescribed exchanges, was found in 30% of patients during the first 6 months of PD. Patients who were noncompliant with prescribed exchanges at the start of PD had greater rates of death (P = 0.03), transfer to hemodialysis secondary to uremia (P < 0.05), hospitalization (P < 0.001), and days hospitalized (P < 0.001) compared with compliant patients. Delivered Kt/V was 18% less in noncompliant compared with compliant patients (2.1 versus 2.57; P = 0.007). Serial evaluations of compliance in 53 patients showed that 72% were consistently compliant, 2% were consistently noncompliant, 15% were noncompliant at the beginning of PD but became compliant at follow-up, and 11% were intermittently noncompliant. The likelihood of future compliance in a patient compliant at the first home visit was 88%. Patients who were independent with their dialysis exchanges were more likely to be noncompliant (27%) than patients dependent on someone else to perform their dialysis (8%; P = 0.05). Serial 24 hour creatinine excretion was not a useful method to determine compliance. We recommend a home visit during the first 6 months of PD to determine compliance. Those found compliant probably do not need repeated evaluations, whereas noncompliant patients should be reevaluated in a few months. Involving another person in the dialysis might relieve some of the burden on patients who may be initially unable to cope with home dialysis. Identification of noncompliant patients and awareness of risk factors should reduce noncompliance and improve patient outcomes.

Creatinine↗