Southern blot screening for lignin peroxidase and aryl-alcohol oxidase genes in 30 fungal species

Screening to detect genes encoding lignin peroxidase (LiP) and aryl-alcohol oxidase (AAO) has been carried out with 30 fungal strain using DNA probes from genes lpo of Phanerochaete chrysosporium (encoding LiP isoenzyme H8) and aao of Pleurotus eryngii. Evidence for the presence of genes closely related to lpo was found in Bjerkandera adusta, Fomes fomentarius, Ganoderma applanatum, Ganoderma australe, Lentinula degener, Peniophora gigantea, P. chrysosporium, Phanerochaete flavido-alba and Trametes tersicolor, whereas the gene aao was detected in Pleurotus species and B. adusta. The presence of both genes was only detected in B. adusta. These results suggest that different enzymatic system, formed by enzymes encoded by different genes, are responsible for lignin degradation by white-rot fungi.

The cloning of a new peroxidase found in lignocellulose cultures of Pleurotus eryngii and sequence comparison with other fungal peroxidases

We report cloning and sequencing of gene ps1 encoding a versatile peroxidase combining catalytic properties of lignin peroxidase (LiP) and manganese peroxidase (MnP) isolated from lignocellulose cultures of the white-rot fungus Pleurotus eryngii. The gene contains 15 putative introns, and the deduced amino acid sequence consists of a 339-residue mature protein with a 31-residue signal peptide. Several putative response elements were identified in the promoter region. Amino acid residues involved in oxidation of Mn(2+) and aromatic substrates by direct electron transfer to heme and long-range electron transfer from superficial residues as predicted by analogy with Phanerochaete chrysosporium MnP and LiP, respectively. A dendrogram is presented illustrating sequence relationships between 29 fungal peroxidases.

Prevalence of CagA and VacA antibodies in children with Helicobacter pylori-associated peptic ulcer compared to prevalence in pediatric patients with active or nonactive chronic gastritis

VacA and CagA serological responses were detected in pediatric patients: 44 and 56%, respectively, in peptic ulcer (PU) patients, 33.3 and 44.4% in active chronic gastritis (ACG) patients, and 23.2 and 39.2% in non-ACG patients. Higher seroprevalence to CagA+VacA and to CagA+VacA+35-kDa antigen was found among PU patients. However, a low level of sensitivity and specificity was found for indirect detection of PU patients.

Susceptibility of Helicobacter pylori to mupirocin, oxazolidinones, quinupristin/dalfopristin and new quinolones

The in vitro activities of mupirocin, quinupristin/dalfopristin, linezolid, eperezolid, sitafloxacin, clinafloxacin, moxifloxacin, amoxycillin, metronidazole and clarithromycin were tested at pH 7.4 against 57 strains of Helicobacter pylori. The most active agents (mupirocin, sitafloxacin and clinafloxacin) were also tested for activity at pH 5.4 against the same strains. Mupirocin was very active at pH 7.4 and 5.4 (MIC90 0.25 and 0.12 mg/L, respectively). Quinupristin/dalfopristin, linezolid and eperezolid had low activity (MIC90 4, 8 and 4 mg/L, respectively). Sitafloxacin (MIC90 </= 0.008 mg/L) was the most active fluoroquinolone, while clinafloxacin (MIC90 0.12 mg/L) and moxifloxacin (MIC90 2 mg/L) were least active.

[Risperidone in the treatment of psychotic disorders associated with mental retardation]

INTRODUCTION

The safety and effectiveness of risperidone in patients with a diagnostic of mental retardation and/or psychotic and disturbance disorder was assessed in an open and observational study.

MATERIAL AND METHODS

A total of 127 patients with DSM-III-R diagnoses of mental retardation together with psychotic disturbance (psychotic and/or behaviour disturbance) was included in an open label surveillance study. The study objectives were to evaluate safety and efficiency of risperidone in these patients during a six-month period. Risperidone was assessed by the Clinical Global Impression (CGI), schizophrenia subscales of Scale for Evaluating Emotional Disorders in Severely and Profoundly Mentally Retarded Persons (DASH) and Assessment and Information Rating Profile (AIRP), UKU subscale for neurological side effects and spontaneous reports.

RESULTS

Ten patients (7.9%) were excluded from the statistical analysis due to protocol violation. Seventeen patients (14.5%) dropped out. Risperidone was used at a mean dosage of 2.98 (2.37 mg daily. Risperidone produced a significant reduction, vs baseline, in the mean total scores of CGI and DASH-AIRP scales from day 15 onwards. There was a significant reduction in the total UKU subscale for neurological, autonomic side effects scores and psychotic symptoms. Risperidone was generally well tolerated. During the 6 months of study period, 93.2% of the patients did not suffer any adverse event; the resting 7.7% suffered one or more side effects.

DISCUSSION

In this study, risperidone was a safety and effectiveness treatment in patients with a diagnostic of mental retardation and psychotic and/or disturbance disorder associated.

Isolated demyelinating syndromes: comparison of different MR imaging criteria to predict conversion to clinically definite multiple sclerosis

BACKGROUND AND PURPOSE

Various authors have developed criteria to classify MR imaging findings that suggest the possibility of multiple sclerosis. The purpose of this study was to evaluate and compare the capacity of three sets of MR imaging criteria for predicting the conversion of isolated demyelinating syndromes to clinically definite multiple sclerosis.

METHODS

Seventy patients with clinically isolated neurologic symptoms suggestive of multiple sclerosis were prospectively studied with MR imaging. The MR imaging findings were evaluated by two independent neuroradiologists who were blinded to clinical follow-up data. Based on the clinical outcome at follow-up (presence of a second attack that established clinically definite multiple sclerosis), the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the criteria proposed by Paty et al, Fazekas et al, and Barkhof et al were calculated.

RESULTS

Clinically definite multiple sclerosis developed in 22 (31%) patients after a mean follow-up time of 28.3 months. The criteria proposed by Paty et al and those proposed by Fazekas et al showed identical results: sensitivity, 86%; specificity, 54%; accuracy, 64%; positive predictive value, 46%; and negative predictive value, 89%. The criteria proposed by Barkhof et al showed the following: sensitivity, 73%; specificity, 73%; accuracy, 73%; positive predictive value, 55%; and negative predictive value, 85%.

CONCLUSION

The four dichotomized MR imaging parameters proposed by Barkhof et al are more specific and accurate than the criteria proposed by Paty et al or Fazekas et al for predicting conversion to clinically definite multiple sclerosis.

Clinical and economic impact of a pharmacist-intervention to promote sequential intravenous to oral clindamycin conversion

A multicentre, prospective, controlled study compared the clinical efficacy, safety and economic impact of a pharmacist intervention to promote sequential intravenous to oral clindamycin conversion. A total of 473 patients receiving intravenous clindamycin for at least 72 hours were included in the study. Two groups were established: an intervention group (204 patients) in which an informative sheet recommending the sequential treatment was provided, and a control group (269 patients). Clindamycin was prescribed for respiratory infections in 38.9% and for prophylaxis in surgery in 25.4% of the patients (71% were contaminated surgery). No difference between groups regarding sex, infection severity, health status or clinical progress was observed. Both the step-down treatments after 72 hours of intravenous clindamycin and the change to the oral route later on, were significantly increased with the intervention (p < 0.001, p < 0.001 respectively). No significant differences between both groups were found in the number of patients with adverse effects associated with the i.v. therapy, although the incidence tended to be lower in the intervention group (49/204 intervention versus 85/269 control, p = 0.07). Compliance with the recommended clindamycin dosing regimen was significantly higher in the intervention group, in which 1.3 days reduction of intravenous therapy provided an average cost savings of PTA5246 (95% CI 2556-7935) per treatment. A higher reduction of 1.7 days was achieved in those patients candidates for switch therapy on the third day of intravenous clindamycin. A sequential program with clindamycin may provide a cost-effective alternative to conventional therapy and the introduction of an information sheet is a cost-effective strategy to promote it.

Different fungal manganese-oxidizing peroxidases: a comparison between Bjerkandera sp. and Phanerochaete chrysosporium

Two manganese-oxidizing peroxidases differing in glycosylation degree were purified from fermenter cultures of Bjerkandera sp. They were characterized and compared with the three manganese-oxidizing peroxidase isoenzymes obtained from the well-known ligninolytic fungus Phanerochaete chrysosporium. All the enzymes showed similar molecular masses but those from P. chrysosporium had less acidic isoelectric point. Moreover, the latter strictly required Mn2+ to oxidize phenolic substrates whereas the Bjerkandera peroxidases had both Mn-mediated and Mn-independent activity on phenolic and non-phenolic aromatic substrates. Taking into account these results, and those reported for Bjerkandera adusta and different Pleurotus species, we concluded that two different types of Mn(2+)-oxidizing peroxidases are secreted by ligninolytic fungi.

Biochemical characterization, cDNA cloning and protein crystallization of aryl-alcohol oxidase from Pleurotus pulmonarius

Aryl-alcohol oxidase (AAO) involved in lignin degradation by Pleurotus pulmonarius has been purified and characterized. The enzyme was produced in glucose-peptone medium and isolated in a sole chromatographic step using Sephacryl S-200. The purified enzyme is an extracellular glycoprotein with 14% N-carbohydrate content and an estimated molecular mass of 70.5 kDa and pI of 3.95. The kinetic studies showed the highest enzyme affinity against p-anisyl alcohol, with constants similar to those of Pleurotus eryngii and Bjerkandera adusta AAO but different from the intracellular AAO described in Phanerochaete chrysosporium, which present the highest activity on m-anisyl alcohol. Simultaneously, the cDNA of P. pulmonarius AAO has been cloned and sequenced. The translation of this sequence consisted of 593 amino acids including a signal peptide of 27 amino acids. The comparison with other alcohol oxidases, 35% amino acid identity with glucose oxidase, showed highly conserved amino acid sequences in N-terminal and C-terminal regions, in spite of differences in substrate specificity. Crystallization of AAO, carried out for the first time using the P. pulmonarius enzyme, will permit to obtain a molecular model for this oxidase and establish some characteristic of its catalytic site and general structure.

[Study of the accumulation of lead in the primary teeth]

The purpose of the study was to determine the accumulation of lead in deciduous teeth in children living in the area of Pamplona (Spain). In this manner, we tried to make a relationship between the quantity of lead accumulated in the tooth against certain factors of exposure that were documented on a questionnaire carried out at the time that the tooth was presented. We analysed 457 deciduous teeth using a technique of microwave digestion follow by Atomic Absorption Spectrometry (AAS), to determine the concentration of lead in the sample. The mean lead concentration was 2.60+/-1.36 microg/g (range 0.25-10.71 microg/g). The lead concentration in our study is inferior to those observed in other European studies.

Regulation of peroxidase transcript levels in liquid cultures of the ligninolytic fungus Pleurotus eryngii

A versatile peroxidase able to oxidize Mn(2+) as well as phenolic and nonphenolic aromatic compounds is produced in peptone-containing liquid cultures of Pleurotus eryngii encoded by the gene mnpl. The regulation of its transcript levels was investigated by Northern blotting of total RNA. High-peroxidase transcripts and activity were found in cultures grown in glucose-peptone medium, whereas only basal levels were detected in glucose-ammonium medium. The addition of more than 25 microM Mn(2+) to the former medium did not result in detectable peroxidase transcripts or activity. Potential regulators were also added to isolated mycelium. In this way, it was shown that high transcript levels (in peroxidase-expressing mycelium) were maintained on peptone, whereas expression was not induced in short-term incubation experiments. Similar results were obtained with Mn(2+) ions. Strong induction of mnpl expression was caused by exogenous H(2)O(2) or by continuous H(2)O(2) generation during redox cycling of menadione. By the use of the latter system in the presence of Fe(3+), which catalyzes the reduction of H(2)O(2) to hydroxyl radical, it was shown for the first time that the presence of this strong oxidant causes a rapid increase of the transcripts of a ligninolytic peroxidase. In conclusion, peptone and Mn(2+) affect the levels of transcripts of this versatile peroxidase in culture, and reduced oxygen species induce short-term expression in isolated mycelium, probably via a stress response mechanism.

Heterologous expression of Pleurotus eryngii peroxidase confirms its ability to oxidize Mn(2+) and different aromatic substrates

A versatile ligninolytic peroxidase has been cloned from Pleurotus eryngii and its allelic variant MnPL2 expressed in Aspergillus nidulans, with properties similar to those of the mature enzyme from P. eryngii. These include the ability to oxidize Mn(2+) and aromatic substrates, confirming that this is a new peroxidase type sharing catalytic properties of lignin peroxidase and manganese peroxidase.

[The long-term behavior of the valve bladder as a function of the initial treatment and its effect on early kidney failure]

In approximately 25-40% of infants presenting with posterior urethral valves (PUV) renal insufficiency will develop before adolescence. In some these patients, renal dysplasia, bladder dysfunction and mismanagement may precipitate renal failure at even earlier age. The goals of this study were to determine whether long-term bladder dysfunction was more frequent in children who underwent early temporary pyelostomy than in those who underwent valve ablation, and to know if bladder dysfunction and mismanagement, in some patients, could be responsible of early renal failure. Urodynamic studies were performed in 59 boys with severe PUV divided into two groups based on initial treatment. A) Valve ablation (30 p.); B) Cutaneous pyeloureterostomy (29 p.). At the end of the study 22 boys had chronic renal failure. Of the 59 boys, 42% (25 p.) had bladders with overdistended or normal behaviour, 58% (34 p.) had bladder dysfunction (instability 37%, low compliance 15%, myogenic failure 5%). The 89% of low compliance bladders, 66% of myogenic failure and 23% of those with instability were in CRF. No difference at all was found in bladder function between boys treated as neonates by high diversion or valve ablation. Of the group in chronic renal failure (22 p.), only 7 patients (32%) had bladders with normal behaviour and in five of these patients a mismanagement was directly related with a quicker renal deterioration. The 58% of our boys with severe PUV have some type of bladder dysfunction. Neonatal pyelo-ureterostomy does not increase long-term bladder dysfunction. Surgical mismanagement should be added to bladder dysfunction as contributors to earlier renal failure.

Molecular cloning of aryl-alcohol oxidase from the fungus Pleurotus eryngii, an enzyme involved in lignin degradation

Aryl-alcohol oxidase (AAO), an extracellular enzyme characteristic of fungi from the genus Pleurotus, constitutes a source for H2O2 required in lignin biodegradation. The gene aao has been cloned, sequenced and characterized for the first time in Pleurotus eryngii. Both cDNA and genomic libraries were screened with probes obtained by PCR using as primers oligonucleotides corresponding to the N-terminus and internal sequences of AAO. DNA sequences from positive clones showed a unique open reading frame of 1779 nucleotides interrupted by 12 introns. The conceptual translation of the protein agrees with the partial amino acid sequences obtained from protein sequencing. A search for proteins with related amino-acid sequences revealed that glucose oxidase from Aspergillus niger has 33% identity and 51% similarity. A comparison with other oxidoreductases showed common motifs in both N- and C-terminal regions corresponding, respectively, to the FAD-binding region and the enzyme active site. However, AAO probably has structural differences with other oxidases, as deduced from its unique ability to generate H2O2 from the oxidation of aromatic alcohols.

Metronidazole resistance and virulence factors in Helicobacter pylori as markers for treatment failure in a paediatric population

The eradication rate obtained using the classical triple therapy containing metronidazole, amoxicillin and bismuth citrate, was determined in 57 paediatric patients with digestive disorders, according to the susceptibility to metronidazole of the Helicobacter pylori strains (determined by agar dilution) and the cagA and vacA status (determined by PCR). Eradication was obtained in 38 out of 43 patients (88.3%) infected by H. pylori with metronidazole MIC < or = 2 mg l(-1), in 3 out of 6 patients (50%) when MIC was 4-8 mg l(-1) and in 4 out of 8 patients (50%) when MIC was > 8 mg l(-1). Among patients infected with cagA+ and cagA- strains an eradication rate of 75% (6/8) and 75% (18/24) was found, and 50% (3/6) and 80% (21/26) among vacA s1- and vacA s2-infected subjects (P > 0.05). H. pylori eradication depends on the susceptibility of the strain to metronidazole, being higher in patients infected with susceptible H. pylori. However, according to our data the cagA or vacA status was not an important factor in treatment failure in the eradication of H. pylori.

Description of a versatile peroxidase involved in the natural degradation of lignin that has both manganese peroxidase and lignin peroxidase substrate interaction sites

Two major peroxidases are secreted by the fungus Pleurotus eryngii in lignocellulose cultures. One is similar to Phanerochaete chrysosporium manganese-dependent peroxidase. The second protein (PS1), although catalyzing the oxidation of Mn2+ to Mn3+ by H2O2, differs from the above enzymes by its manganese-independent activity enabling it to oxidize substituted phenols and synthetic dyes, as well as the lignin peroxidase (LiP) substrate veratryl alcohol. This is by a mechanism similar to that reported for LiP, as evidenced by p-dimethoxybenzene oxidation yielding benzoquinone. The apparent kinetic constants showed high activity on Mn2+, but methoxyhydroquinone was the natural substrate with the highest enzyme affinity (this and other phenolic substrates are not efficiently oxidized by the P. chrysosporium peroxidases). A three-dimensional model was built using crystal models from four fungal peroxidase as templates. The model suggests high structural affinity of this versatile peroxidase with LiP but shows a putative Mn2+ binding site near the internal heme propionate, involving Glu36, Glu40, and Asp181. A specific substrate interaction site for Mn2+ is supported by kinetic data showing noncompetitive inhibition with other peroxidase substrates. Moreover, residues reported as involved in LiP interaction with veratryl alcohol and other aromatic substrates are present in peroxidase PS1 such as His82 at the heme-channel opening, which is remarkably similar to that of P. chrysosporium LiP, and Trp170 at the protein surface. These residues could be involved in two different hypothetical long range electron transfer pathways from substrate (His82-Ala83-Asn84-His47-heme and Trp170-Leu171-heme) similar to those postulated for LiP.

Molecular characterization of a novel peroxidase isolated from the ligninolytic fungus Pleurotus eryngii

A haem peroxidase different from other microbial, plant and animal peroxidases is described. The enzyme is secreted as two isoforms by dikaryotic Pleurotus eryngii in peptone-containing liquid medium. The corresponding gene, which presents 15 introns and encodes a 361-amino-acid protein with a 30-amino-acid signal peptide, was isolated as two alleles corresponding to the two isoforms. The alleles differ in three amino acid residues and in a seven nucleotide deletion affecting a single metal response element in the promoter. When compared with Phanerochaete chrysosporium peroxidases, the new enzyme appears closer to lignin peroxidase (LiP) than to Mn-dependent peroxidase (MnP) isoenzymes (58-60% and 55% identity respectively). The molecular model built using crystal structures of three fungal peroxidases as templates, also showed high structural affinity with LiP (C alpha-distance 1.2 A). However, this peroxidase includes a Mn2+ binding site formed by three acidic residues (E36, E40 and D175) near the haem internal propionate, which accounts for the ability to oxidize Mn2+. Its capability to oxidize aromatic substrates could involve interactions with aromatic residues at the edge of the haem channel. Another possibility is long-range electron transfer, e.g. from W164, which occupies the same position of LiP W171 recently reported as involved in the catalytic cycle of LiP.

[Use of the polymerase chain reaction (PCR) for the diagnosis of Helicobacter pylori infection in pediatric patients]

BACKGROUND

Several direct or non direct methods may be used to detect H. pylori infection. A molecular method, PCR with ureA primers, was used in this study in 43 gastric biopsies obtained from paediatric patients with digestive symptomatology and the results were compared with those obtained by histology and culture.

METHODS

Culture and histological stain were performed from gastric biopsies taken at routine endoscopy following standard methodology. A PCR with specific primers for the ureA gene was applied and the 411 pb fragment detected by agarose gel electrophoresis.

RESULTS

From the 43 gastric biopsies, 21 were positive by culture (48.8%), 25 by histology (58.1%) and 29 by PCR (67.4%). In 30 biopsies (69.7%) PCR results were in good agreement with the reference method (histology and/or culture). In 7 biopsies the PCR was positive (16.3%), although the reference method was negative and in 6 (13.9%) the PCR was negative being positive the histology (5 samples) or histology and culture (1 sample).

CONCLUSIONS

PCR shows the highest positive percentage among the methods used. The use of as many methods as possible in the H. pylori infection, increases the diagnosis of the infection.

[Quality in compliance and prescription of nursing treatment orders for injectable drugs]

OBJECTIVES

To analyse the quality of prescription and compliance with nursing treatment orders (NTOs) in primary care teams (PCTs), in order to identify potential problems and establish interventions.

DESIGN

Observational, crossover study.

SETTING

Three health districts in Santa Coloma de Gramenet.

PATIENTS AND OTHER PARTICIPANTS

NTO forms for injectable medication referred to nursing from PCTs between March 1 and November 30, 1996.

MEASUREMENTS AND MAIN RESULTS

1,088 NTO sheets containing 1,119 prescriptions were evaluated. 64.61% of the NTOs came from PCTs. Compliance with the NTO on the length of treatment (63.33%), on length and guidelines taken together (58.00%) and on allergies to medicine (28.31%) was deficient. The most prescribed therapeutic groups were medicines for the locomotive apparatus (36.10%) and drugs for infections (24.66%). 56.03% of prescriptions had high intrinsic value. It was difficult to justify 72.48% of prescriptions.

CONCLUSIONS

Deficiencies were detected in compliance with NTOs, due to the absence of information which was vital for correct administration. There was low-quality prescription and over-use of parenteral administration.

Purification and characterization of peroxidases from the dye-decolorizing fungus Bjerkandera adusta

A peroxidase oxidizing Mn2+ (MnP) is described for the first time in Bjerkandera adusta, a fungus efficiently degrading xenobiotic compounds. The MnP appeared as two isoenzymes, which were purified to homogeneity together with two lignin peroxidases (LiP). Their N-terminal sequences were identical, but the MnP isoenzymes showed more basic isoelectric points and differences in amino acid composition and catalytic properties. The B. adusta LiP is similar to LiP from Phanerochaete chrysoporium. However, the interest of the MnP described here is related to its ability to catalyze Mn(2+)-mediated as well as Mn(2+)-independent reactions on aromatic compounds, which may be of use for applications in biotechnology and environmental technology.

Transformation of industrial dyes by manganese peroxidases from Bjerkandera adusta and Pleurotus eryngii in a manganese-independent reaction

We investigated the transformation of six industrial azo and phthalocyanine dyes by ligninolytic peroxidases from Bjerkandera adusta and other white rot fungi. The dyes were not oxidized or were oxidized very little by Phanerochaete chrysosporium manganese peroxidase (MnP) or by a chemically generated Mn3+-lactate complex. Lignin peroxidase (LiP) from B. adusta also showed low activity with most of the dyes, but the specific activities increased 8- to 100-fold when veratryl alcohol was included in the reaction mixture, reaching levels of 3.9 to 9.6 U/mg. The B. adusta and Pleurotus eryngii MnP isoenzymes are unusual because of their ability to oxidize aromatic compounds like 2,6-dimethoxyphenol and veratryl alcohol in the absence of Mn2+. These MnP isoenzymes also decolorized the azo dyes and the phthalocyanine complexes in an Mn2+-independent manner. The reactions with the dyes were characterized by apparent Km values ranging from 4 to 16 microM and specific activities ranging from 3.2 to 10.9 U/mg. Dye oxidation by these peroxidases was not increased by adding veratryl alcohol as it was in LiP reactions. Moreover, the reaction was inhibited by the presence of Mn2+, which in the case of Reactive Black 5, an azo dye which is not oxidized by the Mn3+-lactate complex, was found to act as a noncompetitive inhibitor of dye oxidation by B. adusta MnP1.