Processing of the papain precursor. The ionization state of a conserved amino acid motif within the Pro region participates in the regulation of intramolecular processing

The cysteine protease papain is synthesized as a 40-kDa inactive precursor with a 107-amino-acid N-terminal pro region. Although sequence conservation in the pro region is lower than in the mature proteases, a conserved motif (Gly-Xaa-Asn-Xaa-Phe-Xaa-Asp-36, papain precursor numbering) was found within the pro region of cysteine proteases of the papain superfamily. To determinate the function to this conserved motif, we have mutagenized at random each of the 4 residues individually within the pro region of the papain precursor. Precursor mutants were expressed in yeast, screened according to their ability to be processed through either a cis or trans reaction, into mature active papain. Three classes of mutants were found. Non-functional propapain mutants of the first class are completely degraded by subtilisin indicating that they are not folded into a native state. Mutants of the second class were neutral with respect to cis and trans processing. The third class included mutants that mostly accumulated as mature papain in the yeast vacuole. They had mutations that had lost the negatively charged Asp-36 residues and a mutation that probably introduces a positive charge, Phe-38His. The precursor of the Phe-38His mutant could be recovered by expression in a vph1 mutant yeast strain which has a vacuolar pH of about 7. The Phe-38His propapain mutant has an optimum pH of autoactivation about one pH unit higher than the wild type molecule. These results indicate that the electrostatic status of the conserved motif participates in the control of intramolecular processing of the papain precursor.

Elevated macrophage migration inhibitory factor and decreased transforming growth factor-beta levels in major depression--no influence of celecoxib treatment

OBJECTIVES

The involvement of an immune process in the pathophysiology of major depression disorder (MDD) was substantiated by studies demonstrating elevated levels of proinflammatory cytokines and prostaglandin E(2) (PGE(2)). Cyclooxygenase-2 (COX-2) inhibitors lead to a reduced production of PGE(2) and have been shown to improve depressive symptoms. We investigated the three immune parameters macrophage migration inhibitory factor (MIF), transforming growth factor-β (TGF-β) and soluble CD14 (sCD14) in a randomized, placebo-controlled trial of the COX-2 inhibitor celecoxib as add-on therapy in patients with MDD treated with reboxetine.

METHODS

Thirty-two patients with depression and 20 healthy controls participated in the study. The patients were treated with reboxetine and celecoxib or placebo. Immune parameters were measured from serum at baseline, after three and five weeks using ELISA.

RESULTS

Celecoxib as add-on strategy resulted in a significant reduction of Hamilton Depression Scale scores compared to placebo. Depressed patients showed significantly elevated MIF (p < 0.001) and reduced TGF-β (p = 0.006) concentrations at baseline. There was no difference in sCD14-concentrations. There was no difference between the placebo and the celecoxib group and no change over time.

LIMITATIONS

Limitations of the study are the relatively small sample size and lack of functional assessment of HPA axis in parallel.

CONCLUSIONS

MIF is a promising new candidate in the neuro-immune interplay that may link depressive symptoms, altered immune state and HPA-axis dysregulation. Reduced levels of TGF-β replicate previous findings and support the importance of this regulatory cytokine in major depressive disorder.

Neurocognition and its influencing factors in the treatment of schizophrenia-effects of aripiprazole, olanzapine, quetiapine and risperidone

BACKGROUND

To examine influencing variables of neurocognition in patients with schizophrenia and to predict cognition during antipsychotic treatment.

METHODS

Data were obtained from patients with an acute episode of schizophrenia participating in two double-blind and one open label trial comparing the effects of different atypical antipsychotics on cognition. In total, 129 patients were enrolled in this analysis. Cognitive function was assessed at admission, week 4 and 8. Efficacy and tolerability were assessed weekly using the Positive and Negative Syndrome Scale (PANSS) and the Simpson Angus Sale (SAS). Patients were treated with aripirazole, olanzapine, quetiapine and risperidone. Regression analysis including mixed effect models was performed.

RESULTS

A significant improvement in all cognitive domains was observed from baseline to week 8. Regarding the antipsychotic treatment applied quetiapine seemed to achieve the most favourable cognitive improvement. Negative and depressive symptoms, the patient's age and the concomitant and antipsychotic treatment applied were observed to significantly influence and predict neurocognition.

CONCLUSION

The results may indicate that schizophrenia is a static disorder with trait and state dependent cognitive components especially in the memory domains. The influence of negative and depressive symptoms should be considered in daily clinical routine.

Characterization of highly purified, inactivated HIV-1 particles isolated by anion exchange chromatography

This report characterizes inactivated, gp120 depleted, HIV-1 particles purified by an anion exchange chromatography production process. This antigen formulated with incomplete Freund's adjuvant constitutes Remune, which is being evaluated in a phase III clinical endpoint trial to determine the effect of this immune-based therapy on clinical progression of HIV-1 seropositive patients. Multiple production lots of the inactivated HIV-1 antigen strain HZ321, isolated by anion exchange chromatography, exhibit purity of > 95% by gel filtration. These findings are corroborated by thin section electron microscopy showing a homogenous field of intact particles. Analyses of the purified virus particles for protein, lipid, carbohydrate and RNA show structural retention of the envelope proteins, lipid bilayer and core components after large scale processing. The qualitative identification of at least 85% of total HIV-1 protein is determined by ELISA, Western blot, HPLC and amino acid sequencing analyses. Quantitative values are assigned to 50% of these proteins. The data confirm the presence of virally encoded proteins p6, p7, pI15, p17, p24, p32, pI39Gag, gp41, pp55Gag, p66/51, Vpr, Vif and Nef. Excellent consistency between production lots and equivalency to HIV-1 preparations purified by sucrose density gradient sedimentation has been established for protein and lipid composition, and overall purity. These findings further establish that non-viral encoded proteins and lipids are integral structural components of the intact virion and are not contaminants unique to a particular isolation method. The data confirm the presence of multicomponent antigens in the viral particles for stimulating a broad HIV-1 specific immune response. Finally, the work demonstrates that the two inactivation procedures (beta-propiolactone and gamma irradiation), which achieve efficient viral inactivation meeting US FDA guidelines, do not damage the protein antigens of the viral particles.

Effect of aripiprazole on cognition in the treatment of patients with schizophrenia

BACKGROUND

The aim of this study was to assess the cognitive effects of aripiprazole in inpatients with schizophrenia.

METHODS

This was an investigator-initiated, open label eight-week trial evaluating 56 inpatients with the DSM-IV diagnosis of schizophrenia. Efficacy was assessed weekly using the Positive and Negative Syndrome Scale (PANSS) and tolerability was assessed each week using the Udvalg for Klinske Undersogelser side effect rating scale (UKU). Cognitive function was assessed at baseline, week 4 and week 8.

RESULTS

Aripiprazole showed significant improvement in PANSS total score and all subscores between baseline and endpoint visit. The substance was very well tolerated. Patients improved significantly in verbal memory, reaction time and reaction quality/attention from baseline to week eight. Furthermore, mean z-values of individual cognitive domains summarized in a global cognitive index improved significantly from baseline to week eight.

DISCUSSION

Our results suggest that aripiprazole provides a valuable treatment option for patients with schizophrenia.

Phenotypic analysis of human immunodeficiency virus (HIV) type 1 cell-mediated immune responses after treatment with an HIV-1 immunogen

It was hypothesized that immune recognition could be stimulated with combined immune-based and potent antiviral drug therapies. This study examined human immunodeficiency virus type 1 (HIV-1)-specific lymphocyte proliferation before and after treatment with an inactivated HIV-1 immunogen in 15 chronically infected HIV-1 seropositive subjects. Lymphocyte proliferation to the immunizing antigen (gp120-depleted HIV-1; P<.001), purified native p24 (P<.001), and recombinant p24 (P<.05) increased after treatment with the HIV-specific immune-based therapy. By HIV-1 antigen-specific flow cytometry, T helper CD4 lymphocytes, CD8 lymphocytes, and NK cells (all P<.001) were the predominant cell types proliferating in vitro after treatment. Additional phenotyping of proliferating cells revealed predominantly CD4 and CD8 memory (both P<.001) phenotypes. This study supports the concept that in vitro lymphocyte proliferation to HIV-1 antigens, augmented after treatment with an inactivated HIV-1 immunogen, involves primarily CD4 and CD8 cell memory immune responses.

Nucleoli visualized by silver staining combined with a new RNA-specific fluorochrome

A technique for distinguishing nucleolar components by light microscopy is described. Silver staining is used for localizing nuceolar-organizing regions. A new RNA-specific fluorochrome, 4''-6-bis(2'-imidazolinyl-4'-5'H)-2-phenyl-4'-phenoxyindole, visualizes the RNA-containing "partes fibrillares et granulares" of the nucleolus. Both staining procedures can be combined to analyze nucleolar structure and function by light microscopy.

The inhibition of yeast enolase by Li+ and Na+1

The activity of yeast enolase is inhibited by Li+ and Na+. At pH 7.1, inhibition by Li+ is "mixed" with respect to Mg2+; both Vmax and Km (Mg2+) are increased by Li+. The inhibition by Li+ appears to be partial, indicating that enzyme with Li+ bound is active. The step inhibited by Li+ cannot be proton abstraction since Li+ decreases the kinetic isotope effect on Vmax. At pH 9.2, where proton abstraction is no longer partially rate-limiting, inhibiton by Li+ is competitive with respect to Mg2+. The rate of enzyme-catalyzed exchange of the C-2 hydrogen with solvent is not affected by Li+. We interpret these results as follows: Li+ (and Na+) binds to enolase and decreases the rate of at least one step in the mechanism. At pH 7.1, this step is partially rate-limiting; at pH 9.2, this step is a fast step in the reaction. The step inhibited by Li+ cannot be proton abstraction but may be release of product (phosphoenol pyruvate) or Mg2+.

The RSM-scale: a pilot study on a new specific scale for self- and observer-rated quality of life in patients with schizophrenia

PURPOSE

To develop and evaluate a self- and observer-rating scale on quality of life in patients suffering from schizophrenia with regard to the efficacy of atypical antipsychotics based on different dimensions and to apply within a pilot study.

METHODS

Following review of existing scales and a prevalidation phase, the Riedel-Spellmann-Musil (RSM) scale was developed comprising 36 items assigned to different subscales. As reference scales, the Quality of Life Scale (QLS) and the Subjective Well-being Under Neuroleptic Treatment Scale-short version (SWN-K) were performed, psychopathology and adverse events were measured at all visits. Reliability was assessed using Cronbach's alpha, Pearson's correlation coefficients were used to assess construct validity, and Intraclass Correlation Coefficients (ICCs) were used for test-retest reliability. T tests were performed in normal distributed samples; otherwise Wilcoxon tests were used.

RESULTS

One hundred and thirty-six patients were included in the study. Cronbach`s α was 0.917 for the self-rating and 0.915 for the interviewer-rating part. ICCs were >0.70 for all subscales. The self-rating part correlated strongly with the SWN-K and the observer part with the QLS. Changes in psychopathology over the study period and different levels of functioning were detected.

CONCLUSION

The RSM-scale is a new scale to assess the quality of life in different dimensions of patients with schizophrenia treated with antipsychotics and shows good internal consistency, test-retest reliability, construct and discriminant validity.

On the structure and polymorphism of the human chromosome no. 15

Chromosome preparations from 67 randomly selected healthy individuals were consecutively stained with silver, mithramycin, pentamidine-DAPI, and quinacrine mustard. In the short arm of the chromosome 15 up to six regions, which were highly polymorphic, apparently independently of each other, could be detected by the given methods. The frequency of occurrence of each individual polymorphic feature in the population investigated ranges from 70% to 87%. They appear randomly and independently of each other.

[Rational methods of crown preparation]

Today, a rational technique of crown preparation seems to be defined by the following features: 1. Speed-conscious operation 2. Sectionalization into a phase of coarse preparation and a phase of fine preparation 3. Phase-synchronous and segment-oriented coarse preparation in the maximum speed range 4. Fine preparation by means of abrasive tools to achieve a defined preparation limit in the high-speed range 5. Finishing with the aid of properly formed diamond stones or tungsten-carbide finishers in the normal speed range 6. Speed-dependent supply of cooling water according to the principle of double safety (spray and additional cooling).