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Biomedical subjects

A Schuler

Publications and source records attributed to A Schuler.

At least 19 recordsLinked to original sources
PubMed2002

Determination of molecules regulating gene delivery using adenoviral vectors in ovarian carcinomas.

Gene therapeutic approaches currently favor adenoviral vectors over alternatively available vector systems. Ovarian cancer represents an attractive model for an intraperitoneal adenovirus-based gene therapy, which is now under intensive clinical investigation. Adenovirus-mediated gene transfer depends on adequate virus uptake and thus on the presence of sufficient amounts of high-affinity coxsackie-adenovirus receptor (CAR) and alphavbeta3- and alphavbeta5 integrins on target cells. This fact has been ignored in most ongoing clinical trials. This investigation, therefore, determined expression of CAR by immunohistochemistry in 37 ovarian carcinomas and compared it with that of alphavbeta3 and alphavbeta5 integrins. In all samples, except one undifferentiated carcinoma, CAR was immunohistochemically demonstrable. Grade 1 tumors exhibited stronger CAR immunostaining as compared with higher-grade cancers (P < 0.03). Integrins alphavbeta3 and alphavbeta5 were detectable in 62% and 65% of carcinomas, respectively, and staining for both classes correlated positively (P < 0.005). Cancers classified as undifferentiated completely lacked alphavbeta3 expression. Furthermore, in undifferentiated and grade 3 carcinomas the three molecules studied exhibited marked distributional heterogeneity with regard to focal positivity and negativity within the same tumor. Either the absence of CAR, alphavbeta3 and alphavbeta5 or the pronounced heterogeneity in their expression might seriously compromise the efficiency of adenovirus-based gene therapy in ovarian cancer.

Adenoviridae↗
PubMed2001

Variance of ACE and AT1 receptor gene does not influence the risk of neonatal acute renal failure.

High neonatal activity of the renin-angiotensin system (RAS) is crucial for the maintenance of glomerular filtration of the newborn. The aim of the present study was to investigate whether genetic polymorphisms leading to lower angiotensin converting enzyme activity (ACE) or impaired functionality of angiotensin II (AII) type 1 receptor (AT1R) might predispose very low birth weight newborns (VLBWs) to the development of acute renal failure (ARF). The medical records of 110 VLBW infants were analyzed. ARF developed in 42 of them during the first postnatal week, while 68 neonates exhibited normal renal function. The ACE I/D polymorphism and the A1166C variants of AT1R were determined from dried blood samples. The frequency of the ACE I allele did not differ in ARF and non-ARF groups (0.307 and 0.284); the frequency of the AT1R C1166 variant was also the same in ARF and non-ARF groups (0.250 and 0.227). Although low activity of RAS has been implicated in the development of neonatal ARF and data indicated that the functionality of RAS is influenced by the I/D variants of the ACE gene and the A1166C variant of the AT1R gene, we could not demonstrate any effect of these polymorphisms on the development of ARF in VLBW infants.

Acute Kidney Injury↗
PubMed2001

Genetic variants of the tumour necrosis factor-alpha promoter gene do not influence the development of necrotizing enterocolitis.

UNLABELLED: Previous studies indicated that elevated tumour necrosis factor-alpha (TNF-alpha) levels may play a role in the development of necrotizing enterocolitis (NEC). The A(-308) and A(-238) variants of the promoter region of the TNF-alpha gene are reportedly associated with altered TNF-alpha production. The aim of our study was to determine the impact of these gene polymorphisms on the development and course of NEC in very-low-birthweight (VLBW) infants. Dried blood samples from 46 VLBW neonates with NEC were analysed using the method of restriction fragment length polymorphism. Samples from 90 VLBW neonates without NEC were used as controls. The prevalence of alleles with guanine-adenine transition in the -308 and -238 positions was the same in NEC and control subjects (12% vs 10% and 3% vs 4%, respectively). CONCLUSION: The investigated genetic variants of the TNF-alpha gene promoter region have no influence on the risk and course of NEC in VLBW infants.

Adenine↗
PubMed2001

Increasing joint attention, play and language through peer supported play.

The purpose of the present study was to examine the effects of participation in an integrated play group on the joint attention, symbolic play and language behavior of two young boys with autism. Two 6-year-old twin brothers participated in this study, along with three typically developing girls, ages 5, 9 and 11. A multiple baseline design was used with three phases: no intervention, intervention with adult coaching, and intervention without adult coaching. After being trained, the three typically developing children implemented the integrated play group techniques in 30 minute weekly play group sessions for over 16 weeks. Results indicate that participation in the integrated play group produced dramatic increases in shared attention to objects, symbolic play acts, and verbal utterances on the part of the participants with autism. These increases were maintained when adult support was withdrawn. Implications of these findings for inclusion of children with autism are discussed.

Attention↗
PubMed2001

Advocacy groups dismayed by lack of funding in president's budget.

HIV/AIDS advocates have expressed dismay, if not surprise, over the proposed funding for domestic HIV programs outlined in the budget submitted in the spring by President George W. Bush. Despite the reality of rising drug costs and increasing numbers of newly infected Americans, the Ryan White CARE Program was flat-funded in the proposal. Other programs fared no better, except for research and international HIV funding.

Budgets↗
PubMed2000

Distribution of Q188R and N314D mutations in the Hungarian galactosemic population.

The most common causes of galactosemia are mutations of the gene coding galactose-1-phosphate uridyltransferase. Since genotype may correlate with the outcome of the disease, and probably not all of the naturally occurring disease associated mutations are described, characterization of the genotypes in different galactosemic populations are in progress. So far the most extensively examined mutations are the Q188R and the N314D. The first one is associated with the classical galactosemia producing a severe clinical picture with an early onset in homozygous patients. The N314D mutation is associated with the Duarte phenotype, which means a milder form of the disease with a later onset of the symptoms. We studied these mutations in the whole Hungarian galactosemic population by PCR and restriction analysis. We have found the frequency of the Q188R mutation at 33.3%, and the N314D mutation at 11.1%. These results differ from other published data in any other populations. Since the incidence of the disease is the same in Hungary as in other European countries, our study suggests that it is worth to investigate for other mutations in the Hungarian population, of which frequency should be consequently higher.

Amino Acid Substitution↗
PubMed2000

Identification of polyphosphate-accumulating organisms and design of 16S rRNA-directed probes for their detection and quantitation.

Laboratory-scale sequencing batch reactors (SBRs) as models for activated sludge processes were used to study enhanced biological phosphorus removal (EBPR) from wastewater. Enrichment for polyphosphate-accumulating organisms (PAOs) was achieved essentially by increasing the phosphorus concentration in the influent to the SBRs. Fluorescence in situ hybridization (FISH) using domain-, division-, and subdivision-level probes was used to assess the proportions of microorganisms in the sludges. The A sludge, a high-performance P-removing sludge containing 15.1% P in the biomass, was comprised of large clusters of polyphosphate-containing coccobacilli. By FISH, >80% of the A sludge bacteria were beta-2 Proteobacteria arranged in clusters of coccobacilli, strongly suggesting that this group contains a PAO responsible for EBPR. The second dominant group in the A sludge was the Actinobacteria. Clone libraries of PCR-amplified bacterial 16S rRNA genes from three high-performance P-removing sludges were prepared, and clones belonging to the beta-2 Proteobacteria were fully sequenced. A distinctive group of clones (sharing >/=98% sequence identity) related to Rhodocyclus spp. (94 to 97% identity) and Propionibacter pelophilus (95 to 96% identity) was identified as the most likely candidate PAOs. Three probes specific for the highly related candidate PAO group were designed from the sequence data. All three probes specifically bound to the morphologically distinctive clusters of PAOs in the A sludge, exactly coinciding with the beta-2 Proteobacteria probe. Sequential FISH and polyphosphate staining of EBPR sludges clearly demonstrated that PAO probe-binding cells contained polyphosphate. Subsequent PAO probe analyses of a number of sludges with various P removal capacities indicated a strong positive correlation between P removal from the wastewater as determined by sludge P content and number of PAO probe-binding cells. We conclude therefore that an important group of PAOs in EBPR sludges are bacteria closely related to Rhodocyclus and Propionibacter.

Actinobacteria↗
PubMed1999

cDNA cloning of a novel secreted isoform of the human receptor for advanced glycation end products and characterization of cells co-expressing cell-surface scavenger receptors and Swedish mutant amyloid precursor protein.

The receptor for advanced glycation end products (RAGE) has been proposed as a cell surface receptor that binds amyloid-beta protein (Abeta), thereby triggering its cytotoxic effects [S.D. Yan, X. Chen, J. Fu, M. Chen, H. Zhu, A. Roher, T. Slattery, L. Zhao, M. Nagashima, J. Morser, A. Migheli, P. Nawroth, D. Stern, A.M. Schmidt, RAGE and amyloid-beta peptide neurotoxicity in Alzheimer's disease, Nature 382 (1996) 685-691.]. A cDNA library of human lung was screened for RAGE with an appropriate hybridization probe. In addition to cell surface RAGE, one clone was found which encodes a new version of RAGE, termed hRAGEsec, which lacks the 19 amino acids of the membrane-spanning region and is therefore secreted. Comparison with the genomic sequence revealed that the synthesis of the secreted isoform requires alternative splicing. The deduced protein sequence of the mature hRAGEsec consists of 321 amino acids with a predicted molecular mass of 35.66 kDa. The pattern of expression of hRAGEsec in human brain was analyzed by in situ hybridization histochemistry. The most intense expression of the gene in contrast to cell surface RAGE was detected in hippocampal CA3 pyramidal cells, dentate gyrus granule cells, cortical neurons as well as glial cells in white matter. To investigate the interaction between Abeta and RAGE and another scavenger receptor, SRA, under physiological conditions, they were co-expressed with human betaAPP(695)-SFAD in a human cell and the level of Abeta in the condition medium was assessed by immunoprecipitation and enzyme-linked immunosorbent assay (ELISA) analysis. A nearly 100% reduction of Abeta from the conditioned medium of hRAGE cells and approximately 40% reduction from the SRA-cells implied that hRAGE could be a prominent cell surface receptor interacting with Abeta.

Amino Acid Sequence↗
PubMed1999

Reactivity of lysine moieties toward an epoxyhydroxylinoleic acid derivative: aminolysis versus hydrolysis.

Epoxyols are generally accepted as crucial intermediates in lipid oxidation. The reactivity of tert-butyl (9R,10S,11E,13S)-9, 10-epoxy-13-hydroxy-11-octadecenoate (11a,b) toward lysine moieties is investigated, employing N(2)-acetyllysine 4-methylcoumar-7-ylamide (12) as a model for protein-bound lysine. The prefixes R and S denote the relative configuration at the respective stereogenic centers. Independent synthesis and unequivocal structural characterization are reported for 11a,b, its precursors, and tert-butyl (9R,10R,11E, 13S)-10-(¿5-(acetylamino)-6-[(4-methyl-2-oxo-2H-chromen-7-yl)amino ]-6 -oxohexyl¿amino)-9,13-dihydroxy-11-octadecenoate (13a-d). Reactions of 11a,b and 12 in 1-methyl-2-pyrrolidone (MP) and MP/water mixtures at pH 7.4 and 37 degrees C for 56 days show formation of the aminols 13a-d to be favored by an increased water content. The same trend is observed for hydrolytic cleavage of 11a,b to tert-butyl (E)-9,10, 13-trihydroxy-11-octadecenoate (14) and tert-butyl (E)-9,12, 13-trihydroxy-10-octadecenoate (15). Under the given conditions, aminolysis proceeds via an S(N)2 substitution, in contrast with the S(N)1 process for hydrolysis. In the MP/water (8:2) incubation, 15. 8% of 12 has been transformed to 13a-d and 10.5% of 11a,b hydrolyzed to the regioisomers 14 and 15 after 8 weeks, respectively. Aminolysis of alpha,beta-unsaturated epoxides by lysine moieties therefore is expected to be an important mode of interaction between proteins and lipid oxidation products.

Hydrolysis↗
PubMed1999

[An unusual cause of gastrointestinal hemorrhage: pseudoaneurysm of the gastroduodenal artery in chronic pancreatitis].

Pseudoaneurysm of the peripancreatic arteries is a typical cause of gastrointestinal bleeding (GIB) in patients with chronic pancreatitis. 1-10% of chronic pancreatitis are associated with an a pseudoaneurysm, especially of the splenic or gastroduodenal artery. Endoscopy often is not successful in finding the cause of bleeding. Sonography, especially color Doppler ultrasound, is the best diagnostic tool, indicating the need for celiac angiography. We report on a 59-year-old woman with recurrent severe GIB since 1995. In 1998 another bleeding occurred and sonography showed a pseudoaneurysm of the gastroduodenal artery. Typical criteria are an echo-free, pulsatile lesion with an ring-like border. Color Doppler proves a turbulent perfusion inside and shows the feeding vessel. A transcatheter embolization with stainless steel coils was successful, six months later the pseudoaneurysm was mainly obliterated.

Aneurysm↗
PubMed1998

[Incidence of factor V G1681A (Leiden) mutation in samplings from the Hungarian population].

Thromboembolic disorders affect 0.1% of the adult population. Two main groups of the underlying predisposition factors can be identified: environmental factors (e.g. dietary habits, physical activity, surgical interventions, pregnancy etc.) and several genetic predispositions (e.g. inherited anticoagulant defects). After the discovery of the genetic mutation of factor V, called Leiden mutation, it turned out, that this mutation is responsible for the development of resistance to activated protein C in majority of the cases. The importance of the Leiden mutation is further emphasised by population based investigations, which makes it the most frequent thrombosis risk factor known today. In our study we have identified 43 heterozygotes and 3 homozygotes with Leiden mutation in total of 665 samples. The 6.47% heterozigocy is in the range of earlier reports from Europe. The homozygote/heterozygote distribution deviated from the value predicted by the Hardy-Weinberg law.

Adult↗
PubMed1998

[Ligamentum arcuatum syndrome: color doppler ultrasound diagnosis in abdominal pain of unknown origin in young patients].

PURPOSE: To assess the diagnostic potential and accuracy of CDS in the diagnosis and management of visceral artery stenosis in young patients with abdominal pain. METHOD: 126 patients < 45 y with abdominal pain were examined by CDS. Other diseases were excluded before. Systolic (Vmax.sys.) and end diastolic (Vmax.diast.) peak velocities in exspiration and inspiration were measured in the celiac (CA) and superior mesenteric artery (SMA). Vmax.syst. > 1.8 m/s in exspiration and inspiration was regarded as a respiratory fixed stenosis. This was followed by intraarterial digital subtraction angiography (i.a. DSA) including visualization of the pancreaticoduodenal artery (PDA), and, if fixed stenosis was confirmed, by operation. CDS was again performed in the follow-up. RESULTS: CA stenosis were found in 19 patients (mean age 28.9 y). 4 were respiratory fixed, 2 combined with SMA stenoses or occlusion, all proved by i.a. DSA. The others had no evidence of fixed CA stenoses. The 4 operated patients were postoperatively immediately well. One with intermediate pain again had a stenosis in the SMA-bypass which was successfully treated by PTA. The others were treated with dietary procedures and regularly controlled by CDS. CONCLUSION: Ligamentary CA stenosis in young patients is rare, but may lead to considerable abdominal pain and weight loss. Hemodynamicly significant stenoses are proved by CDS with respiratory fixed Vmax.syst. > 1.8 m/s and Vmax.diast. > or = 1 m/s; i.a. DSA often shows a retrograde perfusion of the PDA. Such patients should be treated surgically. CDS should be performed in the follow-up.

Abdominal Pain↗
PubMed1996

Comparative analysis of six European influenza vaccines.

Three split-virion vaccines (Vaxigrip, Begrivac, and Influsplit/Fluarix) and three subunit vaccines containing only viral surface glycoproteins (Influvac, Agrippal, and Fluvirin) available for the 1994-95 season were analysed by biological, molecular, and biochemical methods. Although all vaccines are required by health authorities to contain 15 micrograms haemagglutinin per dose of each virus strain, there were significant differences in haemagglutination titres among the examined vaccines of both types. The enzymatic activity of neuraminidase was present in all vaccines except Fluvirin. Total protein content was lower for subunit vaccines. Viral nucleoprotein was detected in all split vaccines but to varying levels according to SDS-PAGE and Western blot analyses. The ovalbumin content was low in general but was about tenfold higher for Influvac than for the other vaccines analysed. This protein may induce hypersensitive reactions among persons with severe egg allergy. All three split-virion vaccines were found to contain the matrix protein; however, it was not detected in the subunit vaccines. Differences in influenza antigen variety in currently available vaccines may affect efficacy, whereas differences in concentrations of nonviral compounds such as ovalbumin and endotoxin may lead to different postvaccination reactogenicity profiles.

Antigens, Viral↗
PubMed1996

A longitudinal study of phenylketonuria based on the data of the Budapest Screening Center.

Between 1975 and 1994 about 1.5 million neonates were screened by Guthrie tests at the phenylketonuria (PKU) Centre in Budapest. In this period 160 children with PKU were found. The corresponding incidence rate is about 1:9000. In a cumulative longitudinal design we investigated 56 patients with classical PKU between the ages of 3 months and 20.5 years. Treatment started at a mean age of 16.9 days (SD = 8.8). On average, pretreatment phenylalanine (Phe) levels were 1956 mumol/l (SD = 864), measured with the fluorometric method. Their Phe levels, physical growth, intellectual development, and performances in achievement tests were analysed. For the entire sample 45% of half year median Phe levels were in the recommended range, 33% represented poor dietary control, 22% were classified as intermediate. Physical growth was not significantly different from the Hungarian average. Mean verbal as well as nonverbal IQs were in the middle of the normal range. For an extended sample of 131 patients not followed longitudinally, mean recent IQ was 99.6 (SD = 16.3). Data concerning educational career were available for 107 patients. Normal schools were attended by 88 patients, 19 were in need of special elementary education. From 40 patients who had already finished elementary school, 17 underwent secondary school education, 1 is a university student, 15 are skilled workers, 4 were semi-skilled, and 4 are unemployed for reasons unrelated to their intellectual status.

Female↗
PubMed1996

Influenza C virus RNA is uniquely stabilized in a steady state during primary and secondary persistent infections.

The ability to establish persistent infections in vitro and in vivo has been illustrated for different human RNA viruses. However, little insight has been gained regarding the intracellular state of viral RNA species and the regulatory processes governing their long-term continuance. In this report, primary persistence of a variant of influenza C/Ann Arbor/1/50 virus in infected MDCK cells and secondary infections in human cell lines were investigated. Different PCR and staining techniques were applied for the description of low viral loads. The RNA pattern in primary persistence indicates that viral RNA synthesis is quantitatively linked to productive and non-productive phases, with negative-strand RNA being present continuously. In single cells cultures, derived from the primary line, all clones tested were positive by nested PCR and Southern blot screening. This suggests that a true steady-state persistence of influenza C virus is established in each individual cell of the infected population. Secondary infection experiments, in terms of transfer of the persistent virus variant to different cell types, showed that a re-establishment of persistence can be accomplished in vitro. The stable persistent status remained reserved for distinct host cell lines. Hereby, vRNA is stably maintained in cell-type specific manner, whereas gene expression (e.g. HEF glycoprotein production) occurs in a variable fashion. These data point out novel characteristics in the understanding of influenza virus persistence.

Animals↗