CB.Hep-1 hybridoma growth and antibody production using protein-free medium in a hollow fiber bioreactor

The protein-free medium TurboDoma HP.1 (THP.1) was used to produce the CB.Hep-1 monoclonal antibody (mAb) in a CP-1000 hollow fiber bioreactor (HFB). This mAb is used for the immunopurification of recombinant hepatitis B surface antigen (rHBsAg), which is included in a vaccine preparation against the Hepatitis B Virus. By using the experimental conditions tested in this work we were able to generate more than 433 mg of IgG in 43 days. The maximum antibody concentration obtained was about 2.4 mg ml(-1)and the IgG production per day was approximately 11 mg of monoclonal antibody, which constitutes a good concentration value in comparison to the results obtained in ascitic fluid, where concentration for this hybridoma was around 3 mg ml(-1). We used different analytical methods to control the quality of mAbs, obtained from the in vitro system. They included affinity constant determination, analysis of N-glycan structures, immunoaffinity chromatography and antigen binding properties. The results obtained suggest that no significant changes occurred in the mean characteristics of the mAb harvested from the bioreactor during the 43 days of cultivation.

Validity and reliability of the Spanish versions of the Bech-Rafaelsen's mania and melancholia scales for bipolar disorders

OBJECTIVE

To assess classical psychometric properties of the Spanish versions of the Bech-Rafaelsen's mania (MAS) and melancholia (MES) scales.

METHOD

Observational, prospective, and multicentric study in bipolar out-patients. Convergent validity was assessed against the Young Mania Rating Scale and the Montgomery-Asberg Depression Rating Scale. Discriminant validity, reliability, and sensitivity to change, were also assessed.

RESULTS

One hundred and thirteen bipolar patients with a manic episode and 102 bipolar patients with a depressive episode were included. Both the MAS and the MES showed appropriate convergent validity (r > 0.90), discriminant validity (P < 0.0001), internal consistency (Cronbach's alpha >0.80), test-retest reliability [intraclass correlation coefficient (ICC) = 0.69 for the MAS and 0.94 for the MES], inter-rater reliability (ICC > 0.80), and sensitivity to change at 4 weeks since inception (P < 0.0001; within-group effect size >or=1.8).

CONCLUSION

The Spanish versions of both scales present appropriate psychometric estimates in bipolar patients treated in ambulatory care.

The sufficiency of the HAM-D6 as an outcome instrument in the acute therapy of antidepressants in the outpatient setting

Objective. To re-analyse the Spanish outpatient study on the various versions of the Hamilton Depression Scale (HAM-D) by using item-response theory models for measuring unidimensionality. Methods. The Mokken analysis, based on the coefficient of homogeneity, was used. A coefficient of 0.40 or higher was accepted for unidimensionality. The three HAM-D versions were compared: HAM-D6 (core items of depression), HAM-D17 and HAM-D21. Results. In total, 113 of the 116 patients included in the study completed the planned treatment period of 6 weeks. As the Mokken analysis depends as much on the sample of patients under examination (dispersion of scores on the item) as on the scale itself, the endpoint was used. For HAM-D6, but not for HAM-D17 or HAM-D21, the coefficient of homogeneity was acceptable (0.44). Conclusion. The HAM-D6 is a valid version of the Hamilton Scale to be recommended for monitoring depressed patients in antidepressant therapy in the outpatient setting.

[Effectiveness of typical and atypical neuroleptics in the control of behavioral and psychopathological symptoms of dementia. Results of a retrospective study]

INTRODUCTION

Presence of disruptive behavioural and psychological symptoms in dementia (BPSD) is highly prevalent and, as a consequence, neuroleptics are frequently used in these patients to control BPSD. Several reviews have shown the clinical equivalence of different classes of neuroleptics in BPSD control, although that equivalence has been only indirectly assessed by comparing the combined results of different types of active drugs versus placebo. Thus, little is known on the comparative effectiveness, head to head, of different neuroleptics on BPSD. The aim of this study was to gather preliminary information on the effectiveness of typical (haloperidol, thioridazine) and atypical (olanzapine, risperidone) neuroleptics on BPSD.

METHODS

Multicenter, observational and retrospective study using chart reviews of patients with dementia to assess neuroleptic prescriptions and clinical outcomes at 12 weeks on treatment.

RESULTS

No significant differences on BPSD improvement were found by type of neuroleptic (n=78; Kruskal- Wallis exact test; p=0.47). There also were no differences by neuroleptics when the analysis was stratified by levels of cognitive decline (Kruskal-Wallis exact test; p=0.86 and 0.87 for moderate and severe levels of deterioration, respectively). Recorded side effects were worse in the haloperidol group (n=19) regarding rigidity (Fisher's exact; p=0.01), tremor (Fisher's exact p=0.03) and akathisia (Fisher's exact; p=0.03).

CONCLUSIONS

Our findings support the equivalence in effectiveness of several classes of neuroleptics commonly used to treat BPSD. Nevertheless these results need to be confirmed by adequately powered randomized trials and further pharmacoepidemiological studies to assess their safety.

Regulation of actin assembly by SCAR/WAVE proteins

Actin reorganization is a tightly regulated process that co-ordinates complex cellular events, such as cell migration, chemotaxis, phagocytosis and adhesion, but the molecular mechanisms that underlie these processes are not well understood. SCAR (suppressor of cAMP receptor)/WAVE [WASP (Wiskott-Aldrich syndrome protein)-family verprolin homology protein] proteins are members of the conserved WASP family of cytoskeletal regulators, which play a critical role in actin dynamics by triggering Arp2/3 (actin-related protein 2/3)-dependent actin nucleation. SCAR/WAVEs are thought to be regulated by a pentameric complex which also contains Abi (Abl-interactor), Nap (Nck-associated protein), PIR121 (p53-inducible mRNA 121) and HSPC300 (haematopoietic stem progenitor cell 300), but the structural organization of the complex and the contribution of its individual components to the regulation of SCAR/WAVE function remain unclear. Additional features of SCAR/WAVE regulation are highlighted by the discovery of other interactors and distinct complexes. It is likely that the combinatorial assembly of different components of SCAR/WAVE complexes will prove to be vital for their roles at the centre of dynamic actin reorganization.

Expanded bed adsorption processing of mammalian cell culture fluid: comparison with packed bed affinity chromatography

A comparison between expanded bed adsorption and conventional packed bed Protein A Fast Flow to purify the anti-rHBsAg mAbs from feedstock is presented in this work. Direct capture by STREAMLINE expanded bed adsorption chromatography resulted in 92% product recovery and sevenfold more concentrated product with similar purity levels compared to that obtained by the standard packed method. The process time and buffer consumption were reduced in the expanded bed adsorption method not only with the binding-elution conditions but also with the use of NaOH during the cleaning-in-place step. The latter is the most widely accepted agent in downstream processing, being a cost effective technique that provides not only efficient cleaning but also sanitizes complete column systems and destroys pirogens.

Comparison of different ligand densities for the manufacture of CB Hep-1 immunosorbents

Different ligand densities of monoclonal antibody (Mab) CB.Hep-1 were studied during covalent coupling on Sepharose CL-4B for recombinant hepatitis B surface antigen (rHBsAg) immunoaffinity purification. Ligand densities of 2.2, 3.2, 4.2 and 5.2 mg Mab/ml immunosorbents, respectively, were assayed during five cycles of immunoaffinity chromatography (IAC). Adsorption capacities averaged either 3.2 mg/ml (0.57 mg rHBsAg/ml immunosorbent/5.42 mg of total purified protein) or 5.2 mg/ml (0.56 mg rHBsAg/ml immunosorbent/5.05 mg total purified protein). Immunosorbents showed ligand leakage levels below 3 ng Mab/microg rHBsAg. Antigen purity was higher than 95% in all cases. The results suggest that a ligand density (LD) of 3.2 mg Mab/ml immunosorbent should be used for immunoaffinity chromatography because no significant differences were found in the ligand densities studied (P-value=0.012), which saves 40% of CB.Hep-1 immunosorbent manufacturing cost in comparison with 5 mg Mab/ml immunosorbent, which is currently used in large-scale production.

Use of cholinesterase activity in monitoring organophosphate pesticide exposure of cattle produced in tropical areas

The use of cholinesterase activity as a biochemical method for monitoring organophosphate pesticide exposure in cattle is described herein. Determination of cholinesterase activity of whole blood, erythrocyte, and plasma was carried out according to the Ellman modified kinetic method. The mean baseline acetylcholinesterase activities of 9.549 +/- 3.619 IU/mL in whole blood, 9.444 +/- 3.006 IU/mL in erythrocytes, and 0.149 +/- 0.063 IU/mL in plasma were estimated for steers from the control group. Results of multivariate analysis showed that the general responses between the control and experimental groups (in vivo, monitoring and case studies) treated with Coumaphos and Fenthion were statistically different, and the general responses of these experimental groups were statistically different over time as well. Among the fractions that were analyzed, the erythrocyte acetylcholinesterase activity could be adequate for the diagnosis of exposure or acute poisoning in cattle as it showed a good within-run and between-run precision with CVs <10% better than those in plasma.

Monoclonal antibodies against the major coat protein of filamentous phage as a useful analytical tool for bacteriophage peptide/protein display

Four mouse monoclonal antibodies (MAbs) that react with filamentous M13KO7 and R408 phage were obtained. Three of these MAbs (two IgG2a and one IgG3) recognize linear sequences of the p8 main structural coat protein, and one (IgG2a) identifies a putatively conformational epitope, as suggested by Western blot. These MAbs also react with recombinant phage expressing peptide antigens fused to p8, and are though useful reagents for peptide/protein phage display screening based methods. The latter was shown in an enzyme-linked immunoadsorbent assay (ELISA) and a visual immunoassay where one of the anti-p8 MAbs was used to capture recombinant phages displaying a peptide characteristic of the Hepatitis B virus surface antigen or a Dengue virus-related peptide antigen.

Comparison of different elution conditions for the immunopurification of recombinant hepatitis B surface antigen

An immunoaffinity chromatographic method was developed using a mAb immunosorbent to purify recombinant hepatitis B surface antigen (r-HBsAg) from yeast. Elution conditions using a mAb-coated ELISA were improved to select the best conditions to purify r-HBsAg. The optimum results in terms of total quantitative recovery were obtained using 20 mM Tris pH 11.6. An increase in the CB.Hep-1 mAb (anti-HBsAg) useful immunosorbents half-life and in its yield per cycle was obtained when alkaline elution conditions were used. Moreover, the basic conditions do not affect either the antigenic characteristics or the purity or the molecular integrity of r-HBsAg.

Clinical pharmacokinetics of furosemide in children with nephrotic syndrome

The pharmacokinetic disposition of furosemide has been investigated in seven children with nephrotic syndrome and in eight control children. Furosemide in plasma was analyzed by spectrofluorometry. After a single intravenous dose of furosemide (1 mg/kg body wt.) the nephrotic children showed lower initial plasma concentrations because of the larger volume of distribution. The mean half-life of furosemide in nephrotic children (38.5 +/- 7.8 min) was significantly longer than in the control group (28.0 +/- 7.7 min). The two groups did not differ in the body clearance of total furosemide. The average serum clearance was 4.95 +/- 1.7 ml/min/kg body wt. in the control group and 5.10 +/- 1.4 ml/min/kg body wt. in the nephrotic children. There was a significant reduction in urine sodium and distribution volume, whereas potassium excretion remained unchanged.