Biomaterial-dependent MMP-2 expression in fibroblasts from patients with recurrent incisional hernias

With regard to the pathogenesis of recurrent incisional hernia, an impaired connective tissue quality leading to an aberrant scarring process has been proposed. For the matrix metalloproteinase (MMP-2) a pathogenetic involvement in direct inguinal hernia development is reported. With mesh implantation as the gold standard treatment for incisional hernias, the aim of the present study was to investigate the MMP-2 expression in patients with recurrent incisional hernias with and without mesh-materials. In primary fibroblast cultures obtained from skin scars in patients with and without recurrent incisional hernias, MMP-2 synthesis and gene expression were investigated. Furthermore, MMP-2 synthesis and gene expression of fibroblasts were compared after incubation with two different mesh materials: polypropylene and absorbable polyglactin filaments. MMP-2 enzyme activity was determined by semiquantitative zymography and mRNA synthesis by quantitative RT-PCR. Both MMP-2 enzyme activity and mRNA expression were similar in hernia and control fibroblasts in vitro. In control fibroblasts mesh incubation did not significantly affect MMP-2 expression, whereas polypropylene mesh contact of fibroblasts from patients with recurrent incisional hernias led to a major decrease of MMP-2 activity and of mRNA expression. In the absence of biomaterials fibroblasts from recurrent incisional hernia, patients have no alterations of their MMP-2 synthesis compared to control fibroblasts, whereas a specific response was found after biomaterial contact hereby indicating differences in fibroblast phenotype. This work was supported by IZKF-BIOMAT, RWTH-Aachen, project no. TV B66 and by the Deutsche Forschungsgemeinschaft grant KL 1320/2-1     

Are hypodense eosinophils in children activated or immature?

In patients with allergic asthma and rhinitis high numbers of hypodense eosinophils (HE) have been demonstrated. In a previous study we reported that asthmatic and healthy children had more HE than their adult counterparts. We assumed that this might, in part, he due to the presence of immature eosinophils in children. To distinguish between immature and activated eosinophils, determination of eosinophil cationic protein (ECP) might be interesting as it is known that high serum levels of ECP are associated with increased activation of eosinophiis. In this study we determined (he levels of ECP in scrum in asthmatic and healthy children and adults trying to distinguish activated from immature eosinophils. We found that ECP levels were not increased in children (healthy and asthmatic) compared to adults (healthy and asthmatic). This supports the hypothesis that increased numbers of HE in childhood are, at least in part, immature eosinophils. Nevertheless, we could confirm that inflammation was present in children because soluble interleukin-2-receptor (slL-2R), a marker of lymphocyte activation, was higher in asthmatic children as compared to healthy children. IL-6, a marker of macrophage/monocyte activation, was not different in the different patient groups. We conclude that although signs of inflammation are present in childhood asthma, the increased numbers of HE in children are in part due to the presence of immature eosinophils.     

Water-stress-induced changes in the abscisic acid content of guard cells and other cells of Vicia faba L. leaves as determined by enzyme-amplified immunoassay

A highly sensitive, solid-phase, enzyme-amplified immunoassay for the plant growth regulator (+)-abscisic acid (ABA) was developed. The assay sensitivity (0.2-10 fmol) was sufficient for analyzing free ABA in homogeneous tissue samples dissected from Vicia faba L. leaves. Eight hours after detached leaves had been desiccated to 10% loss of fresh weight, the bulk leaf ABA content increased from ≤0.2 to 6.2 ng·(mg dry weight)^-1. Epidermal tissue, spongy parenchyma cells, and palisade parenchyma cells from this water-stressed leaf had the following ABA contents, respectively: 4.8, 9.4, and 9.0 ng·(mg dry weight)^-1. Guard cells, which respond to exogenous ABA by losing solutes and volume, were also assayed. When they were dissected from control (fully hydrated) leaves, their ABA content was ≈0.7 fg·(cell pair)^-1 [[unk]0.2 ng·(mg dry weight)^-1]. In contrast, the ABA content of guard cells of water-stressed leaves was ≈17.7 fg·(cell pair)^-1. These results indicate that ABA accumulation in a highly stressed V. faba leaflet is generalized; guard cells contain only 0.15% of bulk leaf ABA. The time course for loss of ABA from guard cells of a floating epidermal peel was studied. There was little loss within 30 min, but after 4 hr, the ABA content was only 17% of the original value. These results indicate that the bulk of guard cell ABA is not readily diffusible (i.e., probably not apoplastic). The results also indicate that common laboratory procedures results in lowered guard cell ABA content.     

Treatment of motoneuron degeneration by intracerebroventricular delivery of VEGF in a rat model of ALS

Neurotrophin treatment has so far failed to prolong the survival of individuals affected with amyotrophic lateral sclerosis (ALS), an incurable motoneuron degenerative disorder. Here we show that intracerebroventricular (i.c.v.) delivery of recombinant vascular endothelial growth factor (Vegf) in a SOD1(G93A) rat model of ALS delays onset of paralysis by 17 d, improves motor performance and prolongs survival by 22 d, representing the largest effects in animal models of ALS achieved by protein delivery. By protecting cervical motoneurons, i.c.v. delivery of Vegf is particularly effective in rats with the most severe form of ALS with forelimb onset. Vegf has direct neuroprotective effects on motoneurons in vivo, because neuronal expression of a transgene expressing the Vegf receptor prolongs the survival of SOD1(G93A) mice. On i.c.v. delivery, Vegf is anterogradely transported and preserves neuromuscular junctions in SOD1(G93A) rats. Our findings in preclinical rodent models of ALS may have implications for treatment of neurodegenerative disease in general.     

Clonal structural chromosome aberrations in fibrous dysplasia

Cytogenetic analysis of short-term cultures from a case of monostotic fibrous dysplasia in a 14-year-old girl revealed multiple clonal structural rearrangements with evidence of clonal evolution. The karyotype was 46,XX,del(3)(q27),add(10)(q22), add(12)(p13)/46,idem,t(3;8)(p21;q13),add(10)(q26),der(15)del(15)(q15q22)ins(15;?)(q15;?)/46,idem,-X, + 2,t(3;8),add(10),der(15). The finding of clonal structural aberrations suggests that fibrous dysplasia is a neoplastic lesion which develops as the result of somatic mutations.     

Clonal expansion of myelin basic protein-reactive T cells in patients with multiple sclerosis: Restricted T cell receptor V gene rearrangements and CDR3 sequence

Myelin basic protein (MBP)-reactive T cells are thought to play an important role in the pathogenesis of multiple sclerosis (MS). In some patients with MS, these autoreactive T cells display a limited heterogeneity in their epitope recognition and T cell receptor (TCR) variable (V) gene usage. These individual-dependent properties of MBP-reactive T cells have led to the speculation that they may represent clonal expansion in vivo in some MS patients. In the present study, 51 MBP-reactive T cell clones derived from patients with MS and healthy individuals were examined for their epitope recognition and the TCR Vα and Vβ gene rearrangements. The V gene junctional region sequences of identified α and β genes were further analyzed to probe their clonal origins, as the sequences are unique for individual clones. Our data showed that 26 clones derived from nine patients with MS shared a predominant reactivity to the immunodominant regions of MBP, 84–102, 110–129 and 143–168, and used various TCR Vα and Vβ rearrangements. The V gene usage of the clones was restricted to certain Vα Vβ combination(s) in a given MS patient, but varied among different patients. The sequence analysis revealed that the clones generated from a given patient shared a limited or a single junctional region sequence pattern(s), indicating their oligoclonal or monoclonal origin(s). In contrast, 25 MBP-reactive T cell clones derived from normal individuals exhibited unfocused epitope recognition and V gene usage. Thus, the limited heterogeneity of MBP-reactive T cells in their structural and functional charactertistics reflects their clonal expansion in vivo in some patients with MS.     

Normal frequency of chromosome breakage in lymphocytes from patients with musculoskeletal sarcoma

Spontaneous chromosome aberrations were studied in lymphocytes from 23 untreated patients with musculoskeletal sarcoma and 27 controls. Among the sarcoma patients, the mean gap, break, and gap + break events per 100 metaphases were 0.9, 2.2, and 3.0, respectively. The corresponding values for the control group were 1.3, 1.6, and 2.8. The mean number of aberrant mitoses was 2.4% in the sarcoma group and 2.5% in the controls. None of the differences between patients and controls were statistically significant. Thus, we found no evidence of inherent chromosome instability in patients with malignant mesenchymal tumors.