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1.
Clin Pharmacol Drug Dev ; 13(6): 655-664, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38651245

ABSTRACT

Zinpentraxin alfa is a recombinant form of the human pentraxin-2 that was studied in idiopathic pulmonary fibrosis (IPF). To improve the purity and yield of the drug material, a 2nd-generation drug product was developed. To characterize and compare the pharmacokinetic (PK) properties of the 1st- and 2nd-generation zinpentraxin alfa, PK studies were conducted in healthy volunteers (HVs). In a phase 1 randomized, double-blind, 2-sequence crossover, sequential 2-stage study (ISRCTN59409907), single intravenous (IV) doses of 1st- and 2nd-generation zinpentraxin alfa at 10 mg/kg were studied with a blinded interim analysis (IA) at the end of stage 1. Bioequivalence (BE) was achieved for the maximum observed plasma concentration (Cmax), but the overall exposure was higher for the 2nd- compared to the 1st-generation zinpentraxin alfa. The study was stopped after stage 1 as the gating criteria were met based on the result of the blinded IA. Safety profiles were similar for the 1st- and 2nd-generation drug products, and antidrug antibody (ADA) was not observed in this study.


Subject(s)
Cross-Over Studies , Healthy Volunteers , Serum Amyloid P-Component , Therapeutic Equivalency , Humans , Male , Double-Blind Method , Adult , Serum Amyloid P-Component/metabolism , Female , Middle Aged , Young Adult , Recombinant Proteins/pharmacokinetics , Recombinant Proteins/administration & dosage , Recombinant Proteins/adverse effects , Area Under Curve , C-Reactive Protein/metabolism , C-Reactive Protein/analysis , Administration, Intravenous
2.
Anal Chem ; 95(4): 2203-2212, 2023 01 31.
Article in English | MEDLINE | ID: mdl-36669833

ABSTRACT

Antibody combination therapies have become viable therapeutic treatment options for certain severe diseases such as cancer. The co-formulation production approach is intrinsically associated with more complex drug product variant profiles and creates more challenges for analytical control of drug product quality. In addition to various individual quality attributes, those arising from the interactions between the antibodies also potentially emerge through co-formulation. In this study, we describe the development of a widely applicable multi-dimensional liquid chromatography coupled to tandem mass spectrometry method for antibody homo- versus hetero-aggregate characterization. The co-formulation of trastuzumab and pertuzumab was used, a challenging model system, comprising two monoclonal antibodies with very similar physicochemical properties. The data presented demonstrate the high stability of the co-formulation, where only minor aggregate formation is observed upon product storage and accelerated temperature or light-stress conditions. The results also show that the homo- and hetero-aggregates, formed in low and comparable proportions, are only marginally impacted by the formulation and product storage conditions. No preferential formation of hetero-aggregates, in comparison to the already existing pertuzumab and trastuzumab homo-aggregates, was observed.


Subject(s)
Antibodies, Monoclonal , Tandem Mass Spectrometry , Chromatography, Liquid , Antibodies, Monoclonal/chemistry , Trastuzumab/chemistry
3.
Talanta ; 234: 122628, 2021 Nov 01.
Article in English | MEDLINE | ID: mdl-34364437

ABSTRACT

An international study was conducted to evaluate the performance and reliability of an online multi-dimensional (mD)-LC-MS/MS approach for the characterization of antibody charge variants. The characterization of antibody charge variants is traditionally performed by time-consuming, offline isolation of charge variant fractions by ion exchange chromatography (IEC) that are subsequently subjected individually to LC-MS/MS peptide mapping. This newly developed mD-LC-MS/MS approach enables automated and rapid characterization of charge variants using much lower sample requirements. This online workflow includes sample reduction, digestion, peptide mapping, and subsequent mass spectrometric analysis within a single, fully-automated procedure. The benefits of using online mD-LC-MS/MS for variant characterization include fewer handling steps, a more than 10-fold reduction in required sample amount, reduced sample hold time as well as a shortening of the overall turnaround time from weeks to few days compared to standard offline procedures. In this site-to-site comparison study, we evaluated the online peptide mapping data collected from charge variants of trastuzumab (Herceptin®) across three international laboratories. The purpose of this study was to compare the overall performance of the online mD-LC-MS/MS approach for antibody charge variant characterization, with all participating sites employing different mD-LC-MS/MS setups (e.g., instrument vendors, modules, columns, CDS software). The high sequence coverage (95%-97%) obtained in each laboratory, enabled a reproducible generation of tryptic peptides and the comparison of values of the charge variants. Results obtained at all three participating sites were in good agreement, highlighting the reliability and performance of this approach, and correspond with data gained by the standard offline procedure. Overall, our results underscore of the benefit mD-LC-MS/MS technology for therapeutic antibody characterization, confirming its potential to become an important tool in the toolbox of protein characterization scientists.


Subject(s)
Laboratories , Tandem Mass Spectrometry , Antibodies, Monoclonal , Chromatography, Liquid , Humans , Reproducibility of Results
5.
Int J Pediatr Endocrinol ; 2013(1): 21, 2013 Dec 17.
Article in English | MEDLINE | ID: mdl-24344648

ABSTRACT

BACKGROUND: Morbidity and mortality in T1DM depend on metabolic control, which is assessed by HbA1c measurements every 3-4 months. Patients' self-perception of glycemic control depends on daily blood glucose monitoring. Little is known about the congruence of patients' and professionals' perception of metabolic control in T1DM. OBJECTIVE: To assess the actual patients' self-perception and objective assessment (HbA1c) of metabolic control in T1DM children and adolescents and to investigate the possible factors involved in any difference. METHODS: Patients with T1DM aged 8 - 18 years were recruited in a cross-sectional, retrospective and prospective cohort study. Data collection consisted of clinical details, measured HbA1c, self-monitored blood glucose values and questionnaires assessing self and professionals' judgment of metabolic control. RESULTS: 91 patients participated. Mean HbA1c was 8.03%. HbA1c was higher in patients with a diabetes duration > 2 years (p = 0.025) and in patients of lower socioeconomic level (p = 0.032). No significant correlation was found for self-perception of metabolic control in well and poorly controlled patients. We found a trend towards false-positive memory of the last HbA1c in patients with a HbA1c > 8.5% (p = 0.069) but no difference in patients' knowledge on target HbA1c between well and poorly controlled patients. CONCLUSIONS: T1DM patients are aware of a target HbA1c representing good metabolic control. Ill controlled patients appear to have a poorer recollection of their HbA1c. Self-perception of actual metabolic control is similar in well and poorly controlled T1DM children and adolescents. Therefore, professionals should pay special attention that ill controlled T1DM patients perceive their HbA1c correctly.

6.
J Am Chem Soc ; 135(31): 11670-7, 2013 Aug 07.
Article in English | MEDLINE | ID: mdl-23837603

ABSTRACT

Rapid evolution of enzymes provides unique molecular insights into the remarkable adaptability of proteins and helps to elucidate the relationship between amino acid sequence, structure, and function. We interrogated the evolution of the phosphotriesterase from Pseudomonas diminuta (PdPTE), which hydrolyzes synthetic organophosphates with remarkable catalytic efficiency. PTE is thought to be an evolutionarily "young" enzyme, and it has been postulated that it has evolved from members of the phosphotriesterase-like lactonase (PLL) family that show promiscuous organophosphate-degrading activity. Starting from a weakly promiscuous PLL scaffold (Dr0930 from Deinococcus radiodurans ), we designed an extremely efficient organophosphate hydrolase (OPH) with broad substrate specificity using rational and random mutagenesis in combination with in vitro activity screening. The OPH activity for seven organophosphate substrates was simultaneously enhanced by up to 5 orders of magnitude, achieving absolute values of catalytic efficiencies up to 10(6) M(-1) s(-1). Structural and computational analyses identified the molecular basis for the enhanced OPH activity of the engineered PLL variants and demonstrated that OPH catalysis in PdPTE and the engineered PLL differ significantly in the mode of substrate binding.


Subject(s)
Organophosphates/metabolism , Phosphoric Triester Hydrolases/genetics , Phosphoric Triester Hydrolases/metabolism , Pseudomonas/enzymology , Pseudomonas/metabolism , Carboxylic Ester Hydrolases/chemistry , Carboxylic Ester Hydrolases/genetics , Carboxylic Ester Hydrolases/metabolism , Crystallography, X-Ray , Hydrolysis , Models, Molecular , Mutagenesis , Phosphoric Triester Hydrolases/chemistry , Protein Conformation , Pseudomonas/chemistry , Pseudomonas/genetics , Stereoisomerism , Substrate Specificity
7.
Clin Endocrinol (Oxf) ; 76(5): 683-90, 2012 May.
Article in English | MEDLINE | ID: mdl-22026507

ABSTRACT

OBJECTIVE: A number of mathematical models for predicting growth and final height outcome have been proposed to enable the clinician to 'individualize' growth-promoting treatment. However, despite optimizing these models, many patients with isolated growth hormone deficiency (IGHD) do not reach their target height. The aim of this study was to analyse the impact of polymorphic genotypes [CA repeat promoter polymorphism of insulin-like growth factor-I (IGF-I) and the -202 A/C promoter polymorphism of IGF-Binding Protein-3 (IGFBP-3)] on variable growth factors as well as final height in severe IGHD following GH treatment. DESIGN, PATIENTS AND CONTROLS: One hundred seventy eight (IGF-I) and 167 (IGFBP-3) subjects with severe growth retardation because of IGHD were studied. In addition, the various genotypes were also studied in a healthy control group of 211 subjects. RESULTS: The frequency of the individual IGF-I (CA)(n) repeats ranging from 10 to 24, with the most frequent allele containing CA(19), was similar in controls and in IGHD subjects. However, in controls, the pooled CA(19) and CA(20) as well as -202 A IGFBP-3 alleles were significantly (P < 0·01 and P < 0·001) more common in the taller [≥2 to 0 standard deviation score (SDS)] when compared with the shorter subgroup (<0 to ≤-2 SDS). Overall, the effect of recombinant human growth hormone (rhGH) replacement did not reveal any difference between the various genotypes in terms of final height. Independent of their genotype, all subjects showed a slightly lower adult height SDS compared with midparental height SDS. CONCLUSION: Our results indicate that in patients with severe IGHD, although the various IGF-I and IGFBP-3 genotypes may play a role in GH responsiveness, there was no effect on final height.


Subject(s)
Dinucleotide Repeats/genetics , Human Growth Hormone/deficiency , Insulin-Like Growth Factor Binding Protein 3/genetics , Insulin-Like Growth Factor I/genetics , Polymorphism, Genetic , Promoter Regions, Genetic/genetics , Adult , Aged , Body Height/drug effects , Body Height/genetics , Child , Child, Preschool , Female , Gene Frequency , Genotype , Growth Disorders/blood , Growth Disorders/genetics , Growth Disorders/metabolism , Hormone Replacement Therapy , Human Growth Hormone/therapeutic use , Humans , Insulin-Like Growth Factor Binding Protein 3/blood , Insulin-Like Growth Factor I/metabolism , Linear Models , Male , Middle Aged , Multivariate Analysis , Phenotype , Treatment Outcome , Young Adult
8.
Biochemistry ; 48(10): 2237-47, 2009 Mar 17.
Article in English | MEDLINE | ID: mdl-19159332

ABSTRACT

Dr0930, a member of the amidohydrolase superfamily in Deinococcus radiodurans, was cloned, expressed, and purified to homogeneity. The enzyme crystallized in the space group P3121, and the structure was determined to a resolution of 2.1 A. The protein folds as a (beta/alpha)7beta-barrel, and a binuclear metal center is found at the C-terminal end of the beta-barrel. The purified protein contains a mixture of zinc and iron and is intensely purple at high concentrations. The purple color was determined to be due to a charge transfer complex between iron in the beta-metal position and Tyr-97. Mutation of Tyr-97 to phenylalanine or complexation of the metal center with manganese abolished the absorbance in the visible region of the spectrum. Computational docking was used to predict potential substrates for this previously unannotated protein. The enzyme was found to catalyze the hydrolysis of delta- and gamma-lactones with an alkyl substitution at the carbon adjacent to the ring oxygen. The best substrate was delta-nonanoic lactone with a kcat/Km of 1.6 x 10(6) M-1 s-1. Dr0930 was also found to catalyze the very slow hydrolysis of paraoxon with values of kcat and kcat/Km of 0.07 min-1 and 0.8 M-1 s-1, respectively. The amino acid sequence identity to the phosphotriesterase (PTE) from Pseudomonas diminuta is 30%. The eight substrate specificity loops were transplanted from PTE to Dr0930, but no phosphotriesterase activity could be detected in the chimeric PTE-Dr0930 hybrid. Mutation of Phe-26 and Cys-72 in Dr0930 to residues found in the active site of PTE enhanced the kinetic constants for the hydrolysis of paraoxon. The F26G/C72I mutant catalyzed the hydrolysis of paraoxon with a kcat of 1.14 min-1, an increase of 16-fold over the wild-type enzyme. These results support previous proposals that phosphotriesterase activity evolved from an ancestral parent enzyme possessing lactonase activity.


Subject(s)
Amidohydrolases/chemistry , Amidohydrolases/metabolism , Deinococcus/enzymology , Phosphoric Triester Hydrolases/chemistry , Phosphoric Triester Hydrolases/metabolism , Amidohydrolases/genetics , Amino Acid Sequence , Amino Acid Substitution/physiology , Biocatalysis , Catalytic Domain , Crystallography, X-Ray , Deinococcus/genetics , Hydrogen Bonding , Hydrophobic and Hydrophilic Interactions , Kinetics , Lactones/chemistry , Metals, Heavy/chemistry , Models, Molecular , Molecular Sequence Data , Phosphoric Triester Hydrolases/genetics , Protein Conformation , Protein Multimerization , Pseudomonas/enzymology , Pseudomonas/genetics , Recombinant Fusion Proteins/chemistry , Recombinant Fusion Proteins/genetics , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Spectrophotometry , Static Electricity , Structural Homology, Protein , Substrate Specificity
9.
Med Ges Gesch Beih ; 29: 167-83, 263, 2007.
Article in German | MEDLINE | ID: mdl-18354991

ABSTRACT

The German writerJean Paul (Johann Paul Friedrich Richter, 1763-1825) and his friendJohann Bernhard Hermann (1761-1790) became acquainted with the thoughts of late Enlightenment at the University of Leipzig. They particularly appreciated the anthropology of Ernst Platner, who taught philosophy and aesthetics as well as medicine. Their confidential correspondence contains reflections on their respective situation and well being. Both write about feeling ill and label their illness "hypochondria". In the course of the correspondence Jean Paul's understanding of hypochondria evolves from an illness of the entrails as he follows Hermann, who supports the modern concept of hypochondria as an illness of the nerves. Two important themes from this correspondence recur in Jean Paul's novels and tales: firstly, his way of expressing comfort is related to his aesthetics, and secondly, the satirical way of portraying at least certain aspects of illness as imaginary reappears in his first successful novel "The Invisible Lodge" (1793).


Subject(s)
Correspondence as Topic/history , Famous Persons , Hypochondriasis/history , Literature, Modern/history , Medicine in Literature , Germany , History, 18th Century , Humans , Male , Tuberculosis, Pulmonary/history
11.
Swiss Med Wkly ; 134(9-10): 132-5, 2004 Mar 06.
Article in English | MEDLINE | ID: mdl-15106023

ABSTRACT

Critics maintain that family physicians produce radiographic images of poorer technical quality than radiologists but the impact of lower quality images on patient care is unknown. Two radiologists assessed occipitomental radiographs made in either a general practice or a certified laboratory for 247 patients with clinically diagnosed acute bacterial rhinosinusitis. With an occipitomental radiograph correct positioning is more difficult than with the usual radiographs of chest or extremities commonly made in general practice. Good positioning was less common in radiographs from general practices, with the pyramid projected below the maxillary sinuses in 63% of radiographs from general practice and 79% of radiographs from a certified laboratory. However, a radiographic diagnosis of possible acute maxillary sinusitis was as common in radiographs from general practice (38%) as in radiographs from a certified laboratory (41%). Although routine use is not recommended, family physicians with suitable technical and interpretative skills can use an occipitomental radiograph to rule out acute maxillary sinusitis in difficult cases. With a radiograph that is hard to read the physician should act as if the disease is present or refer the radiograph to a consulting radiologist.


Subject(s)
Bacterial Infections/diagnostic imaging , Family Practice , Occipital Bone/diagnostic imaging , Quality of Health Care , Rhinitis/diagnostic imaging , Sinusitis/diagnostic imaging , Acute Disease , Humans , Predictive Value of Tests , Radiography , Reproducibility of Results
12.
Rheumatol Int ; 22(1): 38-40, 2002 May.
Article in English | MEDLINE | ID: mdl-12120910

ABSTRACT

We present the case of a patient with long-standing rheumatoid arthritis and an acute onset of total dysfunction of the posterior tibial tendon. On MRI, a rupture of the tendon was apparent. Intraoperatively, however, massive tenosynovitis with stricture of the tendon was identified as the cause of posterior tibial tendon dysfunction. This case illustrates a pitfall in MRI imaging with potential diagnostic and therapeutic consequences.


Subject(s)
Arthritis, Rheumatoid/complications , Arthritis, Rheumatoid/pathology , Leg/pathology , Muscle, Skeletal/pathology , Posterior Tibial Tendon Dysfunction/etiology , Posterior Tibial Tendon Dysfunction/pathology , Tendons/pathology , Arthralgia/etiology , Arthralgia/pathology , Arthralgia/physiopathology , Arthritis, Rheumatoid/physiopathology , Female , Humans , Leg/physiopathology , Magnetic Resonance Imaging , Middle Aged , Muscle, Skeletal/physiopathology , Orthopedic Procedures , Posterior Tibial Tendon Dysfunction/physiopathology , Tendons/physiopathology , Tenosynovitis/etiology , Tenosynovitis/pathology , Tenosynovitis/physiopathology , Treatment Outcome
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