[The revised version of the Y-BOCS: responsivity and other psychometric properties]. / De herziene versie van de Y-BOCS: responsiviteit en andere psychometrische eigenschappen.

BACKGROUND: The Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) is a widely used semi structured clinician-rated interview to assess the presence and severity of obsessive-compulsive disorder (OCD). The scale is revised (Y-BOCS-II) to overcome several psychometric limitations, for example by extending the scoring for better discrimination within higher severity levels. AIM: To examine the responsiveness and other psychometric properties of the Y-BOCS-II in a Dutch clinical sample. METHOD: The Y-BOCS-II was translated into Dutch (Y-BOCS-II) and administered to 110 patients seeking therapy for OCD. This was done twice, before and after treatment. The original Y-BOCS was simultaneously rated. Self-report measures regarding depression, symptom severity and OCD symptoms were assessed. RESULTS: The Y-BOCS-II had a good internal consistency (Cronbach’s α = 0.84), test-retest (ICC = 0.81) and inter-rater reliability (ICC = 0.94). The construct validity proved to be modest to good. The responsiveness over time was in favour of the Y-BOCS-II, compared with the YBOCS-I, particularly in the severely affected OCD patients. CONCLUSION: The Y-BOCS-II severity scale is a reliable and valid instrument for accurately assessing the severity of OCD symptoms and for measuring treatment-induced change. This second version also has clinical and psychometric advantages over the YBOCS-I. When these findings are sufficiently replicated, use of the YBOCS-II as the new common standard seems recommendable.

Reverse transcription-PCR analysis of the regulation of the manganese peroxidase gene family.

Manganese peroxidase (MnP) gene expression in the lignin-degrading fungus Phanerochaete chrysosporium is regulated by nutrient nitrogen levels and by Mn(II), the substrate for the enzyme, as well as by heat shock and other factors. Reverse transcription-PCR (RT-PCR) of total RNA can distinguish the mRNAs of each of the three sequenced P. chrysosporium mnp genes, i.e., mnp1, mnp2, and mnp3. Quantitative RT-PCR demonstrates that each of the three transcripts is present at a similar low basal level in nitrogen-sufficient cultures, with or without Mn, and in nitrogen-limited cultures lacking Mn. However, in 5-day-old, nitrogen-limited, stationary cultures supplemented with 180 microM Mn, the levels of the mnp1 and mnp2 transcripts increased approximately 100- and 1,700-fold, respectively, over basal levels. In contrast, under these conditions, the level of the mnp3 transcript did not increase significantly over the basal level. Quantitative RT-PCR of total RNA extracted from nitrogen-deficient, Mn-supplemented cultures on days 2 through 7 demonstrates that whereas the mnp1 transcript was present at relatively low levels on days 3 through 7, the mnp2 transcript level peaked on day 5 and the mnp3 transcript level peaked on day 3. Comparison of total RNA extracted on day 5 from nitrogen-deficient, Mn-supplemented stationary and agitated cultures indicates that in stationary cultures, mnp2 was the major expressed mnp gene, whereas in large agitated cultures, mnp1 was the major expressed mnp gene.

Truncated-gene reporter system for studying the regulation of manganese peroxidase expression.

The expression of manganese peroxidase (MnP) in nitrogen-limited cultures of Phanerochaete chrysosporium is regulated by Mn, heat shock (HS), and H2O2 at the level of gene transcription. We have constructed a homologous gene reporter system to further examine the regulation of two mnp genes, mnp1 and mnp2, encoding individual MnP isozymes. Internal deletions of 234 and 359 bp were made within the coding regions of the mnp1 and mnp2 genes, respectively. The truncated mnp genes were subcloned into the shuttle vector pOGI18, which includes the Schizophylum commune ade5 gene as a selectable marker, and transformed into a P. chrysosporium Ade1 auxotrophic mutant. Northern-blot analysis of purified Ade+ transformants demonstrated that both of the truncated mnp genes were regulated in a manner similar to the endogenous mnp genes with respect to nitrogen limitation and induction by Mn, HS, and H2O2.

Characterization of the gene encoding manganese peroxidase isozyme 3 from Phanerochaete chrysosporium.

The gene encoding manganese peroxidase isozyme 3 (MnP3) from the white-rot basidiomycete Phanerochaete chrysosporium was cloned and sequenced. The mnp3 gene encodes a mature protein of 357 amino acids with a 25 amino-acid signal peptide. The amino acids involved in peroxidase function, as well as those forming the MnII binding site and those involved in disulfide bond formation, are conserved in the MnP3 sequence. The mnp3 gene has six introns, indicating that the sequenced P. chrysosporium mnp genes can be divided into three subfamilies on the basis of intron-exon structure. The mnp3 gene promoter contains putative metal response elements and heat shock elements which may be involved in the regulation of mnp gene transcription by Mn, the substrate for the enzyme, and by heat shock.

Regulation of manganese peroxidase gene transcription by hydrogen peroxide, chemical stress, and molecular oxygen.

The expression of manganese peroxidase (MnP) in nitrogen-limited cultures of the lignin-degrading fungus Phanerochaete chrysosporium is regulated at the level of gene transcription by H2O2 and various chemicals, including ethanol, sodium arsenite, and 2,4-dichlorophenol, as well as by Mn(II) and heat shock. Northern (RNA) blot analysis demonstrates that the addition of 1.0 mM H2O2 to 5-day-old cultures grown in the absence of Mn results in the appearance of mnp mRNA within 15 min. Higher levels of mnp mRNA are obtained with simultaneous induction by Mn and H2O2 than with H2O2 alone. Although neither MnP activity nor associated protein is detectable in H2O2-induced cultures grown in the absence of Mn, simultaneous induction with Mn and H2O2 results in a 1.6-fold increase in MnP activity compared with the MnP activity resulting from Mn induction alone. In the presence of Mn, purging of low-nitrogen cultures with 100% O2, in contrast to incubation under air, results in an increase in the accumulation of mnp mRNA and a 13-fold increase in MnP activity on day 5. However, in contrast to the effects of H2O2 and heat shock, O2 purging of Mn-deficient cultures results in negligible accumulation of mnp mRNA.

Homologous expression of recombinant manganese peroxidase in Phanerochaete chrysosporium.

The promoter region of the glyceraldehyde-3-phosphate dehydrogenase gene (gpd) was used to drive expression of mnp1, the gene encoding Mn peroxidase isozyme 1, in primary metabolic cultures of Phanerochaete chrysosporium. A 1,100-bp fragment of the P. chrysosporium gpd promoter region was fused upstream of the mnp1 gene to construct plasmid pAGM1, which contained the Schizophyllum commune ade5 gene as a selectable marker. pAGM1 was used to transform a P. chrysosporium ade1 auxotroph to prototrophy. Ade+ transformants were screened for peroxidase activity on a solid medium containing high carbon and high nitrogen (2% glucose and 24 mM NH4 tartrate) and o-anisidine as the peroxidase substrate. Several transformants that expressed high peroxidase activities were purified and analyzed further in liquid cultures. Recombinant Mn peroxidase (rMnP) was expressed and secreted by transformant cultures on day 2 under primary metabolic growth conditions (high carbon and high nitrogen), whereas endogenous wild-type mnp genes were not expressed under these conditions. Expression of rMnP was not influenced by the level of Mn in the culture medium, as previously observed for the wild-type Mn peroxidase (wtMnP). The amount of active rMnP expressed and secreted in this system was comparable to the amount of enzyme expressed by the wild-type strain under ligninolytic conditions. rMnP was purified to homogeneity by using DEAE-Sepharose chromatography, Blue Agarose chromatography, and Mono Q column chromatography. The M(r) and absorption spectrum of rMnP were essentially identical to the M(r) and absorption spectrum of wtMnP, indicating that heme insertion, folding, and secretion were normal.(ABSTRACT TRUNCATED AT 250 WORDS)