Herpes simplex virus thymidine kinase/ganciclovir-induced apoptosis involves ligand-independent death receptor aggregation and activation of caspases

Suicide gene therapy systems such as the herpes simplex thymidine kinase/ganciclovir system (TK/GCV) may kill cancer cells by apoptosis through as yet undefined mechanisms. Here we show that TK/GCV treatment induces p53 accumulation and increases cell surface expression of CD95 and tumor necrosis factor receptor, which is likely to involve p53-mediated translocation of CD95 to the cell surface. TK/GCV-induced apoptosis involves CD95-L-independent CD95 aggregation leading to the formation of a Fas-associated death domain protein (FADD) and caspase-8-containing, death-inducing signaling complex. Dominant negative FADD, the caspase-8 inhibitor zIETD-fmk [Z-Ile-Glu(OMe)-Thr-Asp(OMe)-fluoromethylketone], and zVAD-fmk (Z-Val-Ala-Asp-fluoromethylketone) partially abrogate TK/GCV-induced apoptosis. In addition to apoptosis induction, TK/GCV treatment strongly sensitizes for CD95-L-, TNF-, and TNF-related, apoptosis-inducing, ligand (TRAIL)-induced cell death in constitutively resistant cells. These findings may be used to increase the efficacy of TK/GCV and other suicide gene therapy systems for the treatment of cancer.     

Molecular genetic analyses in familial and sporadic congenital primary erythrocytosis

Dominant mutations in the erythropoietin receptor (EPOR) gene account for only about 15% of cases of primary congenital erythrocytosis. To search for molecular alterations in patients with this disorder. Sixteen patients with Epo <10 mU/mL were studied, 3 were related. Analyses included EPOR and JAK2 gene sequencing, quantitative PRV-1 RT-PCR, and erythroid colony assays. A novel sporadic EPOR 1453G->A (Trp439Stop) mutation was detected. All familial cases, varied in phenotype, presented the EPOR 1414C->G (Tyr426Stop) mutation. JAK2 mutations are not involved in the pathogenesis of primary congenital erythrocytosis.     

Early relapse in ALL is identified by time to leukemia in NOD/SCID mice and is characterized by a gene signature involving survival pathways

We investigated the engraftment properties and impact on patient outcome of 50 pediatric acute lymphoblastic leukemia (ALL) samples transplanted into NOD/SCID mice. Time to leukemia (TTL) was determined for each patient sample engrafted as weeks from transplant to overt leukemia. Short TTL was strongly associated with high risk for early relapse, identifying an independent prognostic factor. This high-risk phenotype is reflected by a gene signature that upon validation in an independent patient cohort (n?= 197) identified a high-risk cluster of patients with early relapse. Furthermore, the signature points to independent pathways, including mTOR, involved in cell growth and apoptosis. The pathways identified can directly be targeted, thereby offering additional treatment approaches for these high-risk patients.     

Immunohistochemical localization of vascular endothelial growth factor in colonic mucosa of patients with inflammatory bowel disease

BACKGROUND/AIMS: Significantly enhanced serum levels of VEGF (vascular endothelial growth factor) were found in patients with inflammatory bowel disease. Peripheral blood mononuclear cells have been identified as one of the origins of the circulating VEGF. The present investigation examines the localization of VEGF at the site of inflammation in colonic mucosa of patients with Crohn's disease and ulcerative colitis. METHODOLOGY: Immunohistochemical localization of VEGF and immunostaining for leukocytes were performed in colonic mucosal biopsies of 41 patients with Crohn's disease, 26 patients with ulcerative colitis and normal mucosal specimens of 5 patients with irritable bowel syndrome. Measurement of immunohistochemical staining for VEGF and for leukocytes within the epithelium and the lamina propria was performed separately by area morphometry using a computerized cell analysis system. RESULTS: In both patients with Crohn's disease and ulcerative colitis immunohistochemical staining for VEGF within the lamina propria of inflamed colonic mucosa was significantly higher compared with noninflamed mucosa (Crohn's disease: 4.26% vs. 0.07%, P < 0.001; ulcerative colitis: 3.68% vs. 0.32%, P = 0.001). There was a significant correlation between immunostaining for leukocytes and VEGF within the lamina propria in both patients with Crohn's disease (r = 0.73, P < 0.05)) and ulcerative colitis (r = 0.67, P < 0.05). In Crohn's disease immunostaining for VEGF within the epithelium was significantly higher in inflamed mucosa compared with noninflamed mucosa (9.85% vs. 0.63%, P < 0.001). In contrast, strong immunostaining for VEGF has been observed in the epithelium of noninflamed mucosa (7.60%, P < 0.003), as well as in inflamed mucosa of patients with active ulcerative colitis (9.68%, P < 0.002) compared with noninflamed mucosa of patients with inactive ulcerative colitis (1.39%). CONCLUSIONS: The present data indicate, that the increased VEGF expression within the epithelium and the interstitial accumulation of VEGF-producing leukocytes in inflamed mucosa may play an important role in the inflammatory mechanisms of Crohn's disease and ulcerative colitis.     

Abdominale Migräne mit periodischen Bauchschmerzen

Monatsschrift Kinderheilkunde -     

Activation interferes with the APO-1 pathway in mature human T cells

One of the mechanisms to terminate a specific immune responsemay involve elimination of antigen activated T cells by programmedcell death, apoptosis. Apoptosis in activated T cells may beinduced via the TCR-CD3 complex or/and cell surface moleculeslike the APO-1 (Fas) antigen, a new member of the nerve growthfactor/tumor necrosis factor receptor superfamily. To investigateapoptosis in activated T cells we studied expression of APO-1and sensitivity to APO-1 mediated apoptosis in human peripheralT lymphocytes. APO-1 is not expressed on cord blood and themajority of resting T cells, but on activated T cells. One dayactivated T cells in culture showed activation induced resistanceto apoptosis (ARA). However, after prolonged in vitro culture,6 day activated T cells acquired sensitivity to activation inducedsensitivity to apoptosis (ASA). Restimulation of the ASA⁺ activatedT cells by triggering TCR-CD3 or CD2 induced prollferation andapoptosis in a fraction of the cells. In the surviving fractionof ASA⁺ activated T cells, however, this treatment reinduceda transient ARA⁺ phenotype. Thus, activation of resting matureT cells or restimulation of activated T cells may induce a translentresistance to apoptotic signals. Activation signals may interferewith the APO-1 pathway and may prevent elimination of activatedT cells in the periphery (peripheral selection).     

Oral inflammatory changes as an initial manifestation of Crohn's disease antedating abdominal diagnosis

The case of a 14-year-old boy who had oral ulcers with histologic proof of granulomatous disease nine months before the diagnosis of intestinal Crohn's disease is presented. Additional extraintestinal manifestations of this case were cheilitis, anal fissures, and “metastatic” disease to the umbilicus. The diagnosis was established after the onset of abdominal symptoms. All manifestations responded rapidly to systemic prednisone, sulfasalazine, and metronidazole.     

Injection of acidic or neutral insulin and pain: a single-center, prospective, controlled, noninterventional study in pediatric patients with type 1 diabetes mellitus

BACKGROUND: Pain resulting from injections has a potential influence on the acceptance and thus on the success of insulin treatment. Systematic investigation in humans has suggested that individuals perceive more pain during SC injection of acidic solutions than neutral solutions. Insulin glargine is a long-acting (up to 24-hour duration of effect), parenteral blood glucose-lowering agent. Unlike other insulins, it is injected as an acidic solution (pH 4). OBJECTIVE: The aim of this study was to assess whether the SC injection of insulin glargine is more painful than neutral insulin in a clinical setting. METHODS: This single-center, prospective, controlled, noninterventional study was performed in consecutively enrolled male and female pediatric patients (7-21 years) with type 1 diabetes mellitus who self-injected insulin >or=3 times per day and who had diabetes duration of >or=6 months. The study was conducted from September 1, 2005, to December 30, 2005, at the Diabetes Clinic, University Children's Hospital, Ulm, Germany. No changes to the patients' current insulin regimen were made. Based on their existing insulin treatment, patients were assigned to 1 of 2 treatment groups: (1) the acidic insulin group, which injected insulin glargine, and (2) the neutral insulin group, which injected neutral protamine Hagedorn or Semilente insulin. All patients also injected shortacting regular insulin or insulin analogs. Pain during SC insulin injection and during self-monitoring of blood glucose (SMBG) (the internal control) was assessed using a standardized, noninterventional protocol and optimized combined 10-cm visual analog scale and 5-point verbal rating scale (minimum = I cannot feel it at all; maximum = it hurts me). Patients were instructed to document pain immediately after insulin injection and SMBG at home 3 times a day on 3 different days. RESULTS: A total of 112 patients (mean [SD] age, 14.6 [3.0] years; sex, 60 [53.6%] male; mean [SD] glycosylated hemoglobin [HbA(1c)], 8.0% [1.4%]; mean [SD] diabetes duration, 6.1 [3.9] years) completed the study. Pain scores reported by the acidic group (n = 76) were not significantly different when compared with those of the neutral group (n = 36) (4.0 [2.0] vs 4.2 [1.9]). Pain scores were also similar for the injection of short-acting insulin in those from the acidic group when compared with those from the neutral group (3.7 [1.7] vs 4.1 [2.1]). Insulin injections were generally perceived as more painful than SMBG (3.9 [1.7] vs 2.9 [1.8]; P < 0.001). Using the Spearman rank correlation coefficient, pain perception was determined to be independent of age, gender, HbA(1c) level, and duration of diabetes. CONCLUSION: Despite its acidic formulation (pH 4), insulin glargine was not perceived as more painful during SC injection than neutral long-acting or shortacting insulin in these pediatric patients with type 1 diabetes mellitus.