Adalimumab in patients with Crohn's disease--safety and efficacy in an open-label single centre study

AIM

To evaluate the efficacy and safety of adalimumab, a human antitumour necrosis factor-alpha antibody, in induction and maintenance of remission in patients with Crohn's disease either refractory or intolerant to infliximab in a single centre cohort.

METHODS

Sixteen Crohn's disease patients received 160 mg adalimumab subcutaneously in week 0, followed by 80 mg every other week. Clinical response was assessed based on Crohn's disease activity index and laboratory parameters (leukocyte count, C-reactive protein). In all patients genotyping for CARD15 variants and the +1059G/C polymorphism in the C-reactive protein gene was performed.

RESULTS

In 10 of 16 patients (63%) treated with adalimumab, remission (CDAI score <150) was induced for at least 8 weeks independent of CARD15 or +1059G/C CRP status. In six of these 10 patients ongoing remission is observed now for more than 24 weeks. Adalimumab significantly decreased C-reactive protein serum levels and Crohn's disease activity index. There was one serious complication (fungal pneumonia). Six patients intermittently developed minor dermatological problems resolving after topical therapy. Otherwise, treatment was generally well tolerated.

CONCLUSION

Adalimumab can induce and maintain remission in patients with moderate to severe Crohn's disease intolerant or refractory to infliximab. Further experience from larger cohorts is required to evaluate dose regimen and safety profiles in Crohn's disease therapy.

Comparing steroid estrogen, and nonylphenol content across a range of European sewage plants with different treatment and management practices

The effluent of 17 sewage treatment works (STW) across Norway, Sweden, Finland, The Netherlands, Belgium, Germany, France and Switzerland was studied for the presence of estradiol (E2), estrone (E1), ethinylestradiol (EE2) and nonylphenol (NP). Treatment processes included primary and chemical treatment only, submerged aerated filter, oxidation ditch, activated sludge (AS) and combined trickling filter with activated sludge. The effluent strength ranged between 87 and 846 L/PE (population equivalent), the total hydraulic retention time (HRT) ranged between 4 and 120 h, sludge retention time (SRT) between 3 and 30 d, and water temperature ranged from 12 to 21 degrees C. The highest estrogen values were detected in the effluent of the STW which only used primary treatment (13 ng/L E2 and 35 ng/L E1) and on one occasion in one of the STW using the AS system (6.5 ng/L E2, 50.5 ng/L E1, but on three other occasions the concentrations in this STW were at least a factor of 6 lower). For the 16 STW employing secondary treatment E2 was only detected in the effluent of six works during the study period (average 0.7-5.7 ng/L). E1 was detected in the effluent of 13 of the same STW. The median value for E1 for the 16 STW with secondary treatment was 3.0 ng/L. EE2 was only detected in two STW (1.1, <0.8-2.8 ng/L). NP could be detected in the effluent of all 14 STW where this measurement was attempted, with a median of 0.31 microg/L and values ranging from 0.05 to 1.31 microg/L. A comparison of removal performance for E1 was carried out following prediction of the probable influent concentration. A weak but significant (alpha<5%) correlation between E1 removal and HRT or SRT was observed.

Peptidomics: the comprehensive analysis of peptides in complex biological mixtures

Progress in the sequencing of genomes has resulted in an increasing demand for a functional analysis of gene products in order to understand the underlying physiology. Proteomics has established itself as a highly valuable technology for producing functionally related data in an unparalleled fashion, but is methodologically restricted to the analysis of proteins with higher molecular masses (>10 kDa). The development of a technology which covers peptides with low molecular weight and small proteins (0.5 to 15 kDa) was necessary, since peptides, amongst them families of hormones, cytokines and growth factors, play a central role in many biological processes. To summarise the technologies used for this approach the term "peptidomics" is introduced. In this article, we present the rationale and first results of a novel, universal peptide display approach for the analysis and visualisation of peptides and small proteins from biological samples. Special attention is given to samples derived from extracellular fluids such as blood plasma and cerebrospinal fluid. Additionally, a high throughput identification procedure for the analysis of peptides in their native and processed molecular form is outlined.

Screening for disulfide-rich peptides in biological sources by carboxyamidomethylation in combination with differential matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Peptides with biological functions often contain disulfide bridges connecting two cysteine residues. In an attempt to screen biological fluids for peptides containing cysteine residues, we have developed a sensitive and specific method to label cysteines selectively and detect the resulting molecular mass shift by differential mass spectrometry. First, reduction of disulfide bridges and carboxyamidomethylation of free thiols is adjusted to quantitatively achieve cysteine alkylation for complex peptide extracts. In a second step, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) before and after chemical derivatization is performed, followed by differential analysis to determine shifted peaks; shifted peaks belong to cysteine-containing peptides, other peaks remain unchanged. The number of cysteines can then be determined by the resulting molecular mass shift. Free, reduced cysteines are shifted by 57 u, two oxidized cysteines involved in disulfide bridges (cystine) result in a shift to higher mass per disulfide bridge of 116 u. Disulfide bridges connecting different amino acid chains like insulin break up during reduction. In this case, two peaks with lower molecular masses result from a single one in the unmodified sample. With this technique, we were able to identify cysteine-containing peptides and short fragments of proteins present in human blood filtrate.

[Cowpox and catpox infection. 2 Clinical case reports]

In patients with painful, possibly hemorrhagic vesicles or black crusts, especially on hands/fingers or face/neck with typical history (contact to cows or feral/cats) the possibility of a cowpox/catpox infection has to be considered. The clinical diagnosis can be confirmed with the electron microscopy; cytoplasmic inclusions may be detected histologically. Further useful diagnostic tools are the identification of the cowpox/catpox virus by PCR or in cell culture as well as serological tests to detect virus specific antibodies. We report the development of typical skin lesions of a cowpox/catpox infection in two female patients who had contact with cows or cats. Recent diagnostic and therapeutic approaches are also discussed.

The disulfide bond pattern of catrocollastatin C, a disintegrin-like/cysteine-rich protein isolated from Crotalus atrox venom

The disulfide bond pattern of catrocollastatin-C was determined by N-terminal sequencing and mass spectrometry. The N-terminal disintegrin-like domain is a compact structure including eight disulfide bonds, seven of them in the same pattern as the disintegrin bitistatin. The protein has two extra cysteine residues (XIII and XVI) that form an additional disulfide bond that is characteristically found in the disintegrin-like domains of cellular metalloproteinases (ADAMs) and PIII snake venom Zn-metalloproteinases (SVMPs). The C-terminal cysteine-rich domain of catrocollastatin-C contains five disulfide bonds between nearest-neighbor cysteines and a long range disulfide bridge between CysV and CysX. These results provide structural evidence for a redefinition of the disintegrin-like and cysteine-rich domain boundaries. An evolutionary pathway for ADAMs, PIII, and PII SVMPs based on disulfide bond engineering is also proposed.

Disulphide-bond pattern and molecular modelling of the dimeric disintegrin EMF-10, a potent and selective integrin alpha5beta1 antagonist from Eristocophis macmahoni venom

The disulphide-bond pattern of the heterodimeric disintegrin EMF-10, a potent and selective integrin alpha(5)beta(1) antagonist from Eristocophis macmahoni venom, was established by combination of amino-acid analysis, N-terminal sequencing and collision-induced dissociation by nanoelectrospray ionization quadrupole ion-trap MS of fragments isolated by reversed-phase HPLC after degradation of EMF-10 with oxalic acid. Each EMF-10 subunit contains four intrachain disulphide bonds. Two interchain cystine residues join the EMF-10 polypeptides. The intrachain linkages are conserved in monomeric disintegrins. A molecular model of EMF-10 was built using averaged NMR co-ordinates of flavoridin as a template. The active hairpin loops of the EMF-10 subunits occupy opposite locations at the ends of an elongated disulphide-bond ladder. In the EMF-10 model the N-terminal polypeptide of EMF-10B is close to the RGD-loop of the EMF-10A subunit, suggesting that the N-terminal region of the B-subunit could potentially influence the biological activity of the A-subunit.

Composition of the peptide fraction in human blood plasma: database of circulating human peptides

A database was established from human hemofiltrate (HF) that consisted of a mass database and a sequence database, with the aim of analyzing the composition of the peptide fraction in human blood. To establish a mass database, all 480 fractions of a peptide bank generated from HF were analyzed by MALDI-TOF mass spectrometry. Using this method, over 20000 molecular masses representing native, circulating peptides were detected. Estimation of repeatedly detected masses suggests that approximately 5000 different peptides were recorded. More than 95% of the detected masses are smaller than 15000, indicating that HF predominantly contains peptides. The sequence database contains over 340 entries from 75 different protein and peptide precursors. 55% of the entries are fragments from plasma proteins (fibrinogen A 13%, albumin 10%, beta2-microglobulin 8.5%, cystatin C 7%, and fibrinogen B 6%). Seven percent of the entries represent peptide hormones, growth factors and cytokines. Thirty-three percent belong to protein families such as complement factors, enzymes, enzyme inhibitors and transport proteins. Five percent represent novel peptides of which some show homology to known peptide and protein families. The coexistence of processed peptide fragments, biologically active peptides and peptide precursors suggests that HF reflects the peptide composition of plasma. Interestingly, protein modules such as EGF domains (meprin Aalpha-fragments), somatomedin-B domains (vitronectin fragments), thyroglobulin domains (insulin like growth factor-binding proteins), and Kazal-type inhibitor domains were identified. Alignment of sequenced fragments to their precursor proteins and the analysis of their cleavage sites revealed that there are different processing pathways of plasma proteins in vivo.

Human beta-defensin-1: A urinary peptide present in variant molecular forms and its putative functional implication

Human beta-defensin-1 (hBD-1) was first isolated from blood filtrate by our group. Further studies elucidate the significance of this peptide in the human urogenital tract. The hBD-1 gene is expressed in urogenital epithelial organs such as urinary bladder, ureter, vagina and particularly in distal tubular cells of the kidney. Functional characterization of hBD-1 was carried out with native hBD-1 purified from human body fluids. Several different N-terminally truncated variants derived from the 68-amino acid-containing precursor of hBD-1 occur in blood filtrate and in urine. The generation of these variants can be explained by digestion through a chymotrypsin-like protease. Unlike the alpha-defensins which are structurally related peptide antibiotics, our results indicate that native hBD-1 exhibits minor antimicrobial activity which is not related to the extension of the N-terminus. Only few microorganisms, for example bacilli, are significantly inhibited by hBD-1. Moreover, antibiotic activity is suppressed in solutions containing physiological sodium chloride concentrations. This is in contrast to previous reports assuming a pivotal role of hBD-1 in antimicrobial host defense. In contrast to its weak antimicrobial activity, it is shown that hBD-1 has a strong cytotoxic potential towards mammalian cells like NIH-3T3 fibroblasts. We assume that this property might be important during eradicative processes at epithelia in particular when the synthesis rate of this peptide is upregulated.

Isolation and characterization of the circulating form of human endostatin

Recently, fragments of extracellular proteins, including endostatin, were defined as a novel group of angiogenesis inhibitors. In this study, human plasma equivalent hemofiltrate was used as a source for the purification of high molecular weight peptides (10-20 kDa), and the isolation and identification of circulating human endostatin are described. The purification of this C-terminal fragment of collagen alpha1(XVIII) was guided by MALDI-MS and the exact molecular mass determined by ESI-MS was found to be 18 494 Da. N-terminal sequencing revealed the identity of this putative angiogenesis inhibitor and its close relation to mouse endostatin. The cysteine residues 1-3 and 2-4 in the molecule are linked by disulfide bridges. In vitro biological characterization of the native protein demonstrated no anti-proliferative activity on different endothelial cell types. These data indicate that human endostatin, which is a putative angiogenesis inhibitor, is present in the circulation.

Peptide bank generated by large-scale preparation of circulating human peptides

Human hemofiltrate (HF) is a source for the purification of circulating regulatory peptides. HF is obtained in large quantities during treatment of patients suffering from chronic renal failure. We have developed a large-scale method for separating peptides from amounts up to 10,000 1 HF into 300 fractions in a standardized two-step procedure, employing cation-exchange separation, followed by reversed-phase chromatography. These fractions represent a peptide bank containing bioactive, desalted and lyophilized peptides of blood. Screening for and isolation of regulatory human peptides is simplified by using this peptide bank.

Matrix-assisted laser desorption/ionisation mass spectrometry guided purification of human guanylin from blood ultrafiltrate

The purification of the human peptide hormone guanylin 22-115 from blood ultrafiltrate (hemofiltrate, HF) was achieved using matrix-assisted laser desorption/ionisation mass spectrometry (MALDI-MS) as the assay system. Screening a peptide bank generated from 5000 1 HF guanylin 22-115 was detected by its molecular mass when adequate conditions for MALDI-MS analysis were chosen. The sensitivity was even better than of the established biological assay system. In addition, the susceptibility towards solvents and salts is strongly reduced. 1.2 mg of the peptide hormone was purified from 10% of the starting material.

Immunohistochemical analysis of procathepsin L and cathepsin B in cutaneous Kaposi's sarcoma

BACKGROUND

The expression of the proteinases cathepsins L and B are induced in tumors by malignant transformation, growth factors, and tumor promoters suggesting they play an important role in tumor invasion and metastasis.

METHODS

By immunohistochemistry, procathepsin L and cathepsin B were studied in patients with Kaposi's sarcoma (KS). Formalin-fixed and paraffin-embedded tissues from 29 cases of KS (AIDS-associated KS, n = 24; non-AIDS-associated KS, n = 5) were immunolabeled with the polyclonal antibody directed against procathepsin L and the antisera directed against cathepsin B.

RESULTS

Normal epidermis, eccrine sweat glands, and hair follicle expressed both cathepsins. We also found a positive staining for procathepsin L in normal blood vessels. In both "angiomatous" and "fibroblastic" lesions of KS no expression of these enzymes was observed.

CONCLUSIONS

These findings support the hypothesis of a benign autochthonous origin of the lesions, such as a hyperplasia.

New insights in the structure and biology of the high affinity receptor for IgE (Fc epsilon RI) on human epidermal Langerhans cells

The recent structural and functional analysis of the high affinity receptor for IgE (Fc epsilon RI) expressed on human epidermal Langerhans cells (LC) revealed new aspects of the biology of this structure. In contrast to basophils and mast cells where this receptor seems to be expressed constitutively at a constant level, the expression of Fc epsilon RI on LC varies on the donor and the inflammatory environment of the cells and lacks the classical beta-chain. This also implies functional differences most probably related to the expression level. Although the signalling pathway seems to be similar to that of basophils or mast cells, LC from individuals with atopic dermatitis are fully activated by receptor ligation while LC from normal individuals fail to exhibit calcium mobilization under the same conditions. Finally, LC from normal and atopic individuals use Fc epsilon RI to maximize antigen uptake via specific IgE and subsequent presentation to T cells. Thus, Fc epsilon RI expressed on LC differs in terms of structure and function from that expressed on effector cells of anaphylaxis.

Activation of human epidermal Langerhans cells by engagement of the high affinity receptor for IgE, Fc epsilon RI

Human epidermal Langerhans cells (LCs) bind IgE via the high affinity receptor (Fc epsilon RI), and therefore are suspected to be involved in the genesis of atopic diseases. In this study, we report that surface expression of Fc epsilon RI is increased dramatically on LCs from patients with atopic dermatitis (AD) when compared with nonatopic individuals. Cross-linking of Fc epsilon RI on LCs from nonatopic individuals and patients with AD leads to a rapid tyrosine phosphorylation of several proteins, including p72, p77, and p95. However, upon receptor ligation, calcium mobilization is only detected in LCs freshly isolated from patients with AD (responder LCs), but not in those from normal skin of healthy individuals (nonresponder LCs). The beta-chain of Fc epsilon RI is not detected in normal LCs and only in a minority of LCs from atopic individuals, indicating that it is not related to the capacity of LCs to respond to Fc epsilon RI-mediated activation. In contrast, LCs from both nonatopic and atopic individuals internalize Fc epsilon RI by receptor-mediated endocytosis as a prerequisite for Ag focusing. Therefore, LCs from normal individuals and individuals with AD differ functionally by their Fc epsilon RI expression and by a distinct ability to respond to Fc epsilon RI-mediated activation.

Activation of human epidermal Langerhans cells by engagement of the high affinity receptor for IgE, Fc epsilon RI

Human epidermal Langerhans cells (LCs) bind IgE via the high affinity receptor (Fc epsilon RI), and therefore are suspected to be involved in the genesis of atopic diseases. In this study, we report that surface expression of Fc epsilon RI is increased dramatically on LCs from patients with atopic dermatitis (AD) when compared with nonatopic individuals. Cross-linking of Fc epsilon RI on LCs from nonatopic individuals and patients with AD leads to a rapid tyrosine phosphorylation of several proteins, including p72, p77, and p95. However, upon receptor ligation, calcium mobilization is only detected in LCs freshly isolated from patients with AD (responder LCs), but not in those from normal skin of healthy individuals (nonresponder LCs). The beta-chain of Fc epsilon RI is not detected in normal LCs and only in a minority of LCs from atopic individuals, indicating that it is not related to the capacity of LCs to respond to Fc epsilon RI-mediated activation. In contrast, LCs from both nonatopic and atopic individuals internalize Fc epsilon RI by receptor-mediated endocytosis as a prerequisite for Ag focusing. Therefore, LCs from normal individuals and individuals with AD differ functionally by their Fc epsilon RI expression and by a distinct ability to respond to Fc epsilon RI-mediated activation.

Characterization of the protein tyrosine phosphatase CD45 on human epidermal Langerhans cells

Human Langerhans cells (LC) express CD45, but clear data about the isoform(s) and their function(s) are lacking. In the present study, double labeling experiments reveal that freshly isolated LC from normal skin are CD45RO+/RA-/RB-. However, after isolation and short-time culture where LC undergo an in vitro maturation resembling that to lymphoid dendritic cells, CD45RB emerges whereas CD45RO expression decreases. This evolution results from dynamic alternative RNA splicing. Addition of granulocyte-macrophage colony-stimulating factor or tumor necrosis factor-alpha to short-time cultures has no significant effect on CD45RB, but both cytokines accelerate the loss of CD45RO. LC isolated from lesional skin of atopic eczema highly express CD45RO and CD45RB. Cross-linking of CD45 on LC isolated from atopic individuals inhibits the calcium mobilization in response to activation via Fc epsilon receptor type I (Fc epsilon RI). Hence, the protein tyrosine phosphatase CD45 from human LC is subjected to a splicing phenomenon related to the differentiation and activation stage of these cells and regulates their Fc epsilon RI-mediated activation.

[Reliability of diagnostic procedures in facial paralysis with special reference to magnetic resonance tomography]

Facial nerve palsy is commonly examined using a variety of topodiagnostic and electrophysiological tests. More recently, MRI has also been used to study lesions of the facial nerve. Due to varying time intervals between the onset of symptoms and clinical examination, however, the diagnostic value of these procedures remains limited. In the present study, 30 patients with facial nerve palsy of diverse origin were examined with MRI (1.5 Tesla magnetom) using a special surface coil and 30 degrees parasagittal slices of 3 mm thickness. These special modifications enabled us to visualize the nerve in its entire course through the temporal bone. After the application of Gd-DTPA the enhancement of the contrast medium could be verified in all cases. A moderate enhancement in the geniculate ganglion as well as in the labyrinthine segment correlated with a good prognosis in terms of complete restoration of facial nerve activity, while an increased enhancement correlated with a poor prognosis. Our results indicate that MRI is of superior diagnostic value as compared to clinical and electrodiagnostic tests, at least in the patients we examined in this study. Still, further evaluations are necessary to justify a possible routine clinical use of this procedure.

[Diagnostic value of intravascular ultrasound diagnosis in peripheral arteriosclerotic blood vessel changes]

Intravascular ultrasound is an adjunct for the diagnosis of atherosclerotic peripheral vessels. In this in-vitro study, 69 segments of human peripheral arteries were fixed in formalin, examined with intravascular ultrasound and pathomorphologically evaluated. Sensitivity, specificity, both positive and negative predictive value and accuracy of intravascular ultrasound for the detection of irregular lumen contours, intraarterial structures and intimal thickening were determined for each of four quadrants. Sonographic features (echogeneity, homogeneity, shadowing of echoes) were compared to the architecture of lesions. Intravascular ultrasound detected regular (normal) lumen contours with high specificity (96.5%), a sensitivity of 65.0%, and an accuracy of 88.4%; intraluminal structures were detected with a sensitivity of 88.6%, a specificity of 97.8%, and an accuracy of 96.4%. Most atherosclerotic lesions could be localized with a sensitivity of 86.1%, a specificity of 99.1%, and an accuracy of 86.9%. Slight intimal thickening was detectable with a sensitivity of 85.9%, a specificity of 87.8%, and an accuracy of 86.2%. Comparison of sonographic features and the pathomorphological architecture of atherosclerotic lesions revealed that fibrous, atheromatous, and complex lesions without calcification did not show shadowing of echoes. The majority of fibrous or atheromatous lesions presented with homogeneous echoes; these lesions showed hypo-, hyper- and normodense echoes. The homogeneity of echoes did not help to identify the different components of combined atherosclerotic lesions. Thus, intravascular ultrasound is able to detect irregular lumen contours, intraluminal structures, and intimal thickening, but further sonographic criteria are needed to identify the architectural structure of combined lesions.

Time-dependent differences in the development of somites of four different mouse strains

In studies on reproductive toxicity and especially teratogenicity, animals are often treated at defined stages of pregnancy. As a result the exposure to a certain teratogen can lead to striking differences in the formation of abnormalities in different strains of the same species. As a contribution to the discussion about the reasons for these differences, we examined the somite development of four different strains of mice during organogenesis. The embryos of pregnant females of the inbred strains DBA/2J, BALB/cJ, and C57BL/6J and of the outbred strain Han:NMRI were studied on days 9, 10, 11, or 12 of gestation. As a criterion for development the somite pairs were evaluated on the respective days. There were remarkable differences in the somite number, even within one litter. The largest variation (minimum vs. maximum) was 14 pairs of somites. The regression curves did not exhibit major differences in the speed of somite development from day 9 to day 12 between the four strains. We have to conclude from our results that the individual embryonic stages within one litter may vary by nearly 1 day, and that there may be a delay of half a day in the embryonic development between different strains of mice.