13 resultados para primordial germ cell

em BORIS: Bern Open Repository and Information System - Berna - Suiça


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PURPOSE: We evaluated the long-term outcome after 1 cycle of adjuvant modified bleomycin, etoposide and cisplatin chemotherapy in patients who underwent orchiectomy for high risk clinical stage I nonseminomatous germ cell tumor of the testis. MATERIALS AND METHODS: Between 1995 and 1999 a consecutive series of 44 patients underwent orchiectomy for clinical stage I nonseminomatous germ cell tumor of the testis, followed by a single postoperative cycle of adjuvant modified bleomycin, etoposide and cisplatin for vascular or lymphatic tumor invasion, and/or a predominance (50% or greater) of embryonal carcinoma. RESULTS: Four of the 44 patients were excluded from analysis. Of the patients 35 had no evidence of disease at a median followup of 99 months (range 60 to 134). One patient with progression after 13 months showed complete remission after 3 cycles of salvage bleomycin, etoposide and cisplatin chemotherapy but he died of pneumonia 4 weeks after the third course. Two patients underwent orchiectomy for contralateral testis cancer at 18 and 42 months, respectively, followed by an additional 3 cycles of adjuvant chemotherapy. They remained relapse-free for 4 and 92 months, respectively. The former patient was lost to followup after 4 months. Two other patients were disease-free at 10 and 31 months, respectively, and were lost to followup thereafter. Late side effects were tinnitus in 3 patients and involuntary childlessness in 3, of whom 2 had cryptorchidism of the contralateral testis. Nine patients fathered children. CONCLUSIONS: One cycle of bleomycin, etoposide and cisplatin effectively decreases the risk of relapse in patients with high risk stage I nonseminomatous germ cell tumor of the testis. It has minimal side effects and can be a valuable alternative to retroperitoneal lymph node dissection.

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Testis cancer is the most frequent solid malignancy in young men. The majority of patients present with clinical stage I disease and about 50% of them are nonseminomatous germ cell tumors. In this initial stage of disease there is a subgroup of patients at high risk with a likelihood of more than 50% for relapse. Treatment options for these patients include: retroperitoneal lymph node dissection (RPLND), albeit 6-10% of patients will relapse outside the field of RPLND, active surveillance with even higher relapse rates and adjuvant chemotherapy. As most of these patients have the chance to become long-term survivors, avoidance of long-term side effects is of utmost importance. This review provides information on the potential of chemotherapy to achieve a higher chance of cure for patients with high-risk clinical stage I disease than its therapeutic alternatives and addresses toxicity and dose dependency.

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BACKGROUND To report the long-term results of adjuvant treatment with one cycle of modified bleomycin, etoposide, and cisplatin (BEP) in patients with clinical stage I (CS I) nonseminomatous germ-cell tumors (NSGCT) at high risk of relapse. PATIENTS AND METHODS In a single-arm, phase II clinical trial, 40 patients with CS I NSGCT with vascular invasion and/or >50% embryonal cell carcinoma in the orchiectomy specimen received one cycle of adjuvant BEP (20 mg/m(2) bleomycin as a continuous infusion over 24 h, 120 mg/m(2) etoposide and 40 mg/m(2) cisplatin each on days 1-3). Primary end point was the relapse rate. RESULTS Median follow-up was 186 months. One patient (2.5%) had a pulmonary relapse 13 months after one BEP and died after three additional cycles of BEP chemotherapy. Three patients (7.5%) presented with a contralateral metachronous testicular tumor, and three (7.5%) developed a secondary malignancy. Three patients (7.5%) reported intermittent tinnitus and one had grade 2 peripheral polyneuropathy (2.5%). CONCLUSIONS Adjuvant chemotherapy with one cycle of modified-BEP is a feasible and safe treatment of patients with CS I NSGCT at high risk of relapse. In these patients, it appears to be an alternative to two cycles of BEP and to have a lower relapse rate than retroperitoneal lymph node dissection. If confirmed by other centers, 1 cycle of adjuvant BEP chemotherapy should become a first-line treatment option for this group of patients.

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The Chromatin Accessibility Complex (CHRAC) consists of the ATPase ISWI, the large ACF1 subunit and a pair of small histone-like proteins, CHRAC-14/16. CHRAC is a prototypical nucleosome sliding factor that mobilizes nucleosomes to improve the regularity and integrity of the chromatin fiber. This may facilitate the formation of repressive chromatin. Expression of the signature subunit ACF1 is restricted during embryonic development, but remains high in primordial germ cells. Therefore, we explored roles for ACF1 during Drosophila oogenesis. ACF1 is expressed in somatic and germline cells, with notable enrichment in germline stem cells and oocytes. The asymmetrical localization of ACF1 to these cells depends on the transport of the Acf1 mRNA by the Bicaudal-D/Egalitarian complex. Loss of ACF1 function in the novel Acf1(7) allele leads to defective egg chambers and their elimination through apoptosis. In addition, we find a variety of unusual 16-cell cyst packaging phenotypes in the previously known Acf1(1) allele, with a striking prevalence of egg chambers with two functional oocytes at opposite poles. Surprisingly, we found that the Acf1(1) deletion - despite disruption of the Acf1 reading frame - expresses low levels of a PHD-bromodomain module from the C-terminus of ACF1 that becomes enriched in oocytes. Expression of this module from the Acf1 genomic locus leads to packaging defects in the absence of functional ACF1, suggesting competitive interactions with unknown target molecules. Remarkably, a two-fold overexpression of CHRAC (ACF1 and CHRAC-16) leads to increased apoptosis and packaging defects. Evidently, finely tuned CHRAC levels are required for proper oogenesis.

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The uncommon simultaneous occurrence of an exuberant, angioma-like proliferation of superficial cerebral microvessels along with absence of the kidneys has been proposed to constitute a syndromic complex for which the term "meningocerebral angiodysplasia (or angiomatosis) with renal agenesis" (MCA-RA) is being descriptively used. We observed this constellation in one of a pair of dichorionic male twins following postpartal death in the 38th week of pregnancy. General autopsy revealed rudimentary metanephric anlagen made up of few residual glomeruli, cysts lined by flattened tubular epithelium, and islands of cartilage - corresponding to renal aplastic dysplasia. Largely inconspicuous with respect to its gyral pattern, as well as the configuration of the ventricular system, the brain microscopically showed extensive replacement of the cortex by a lattice of proliferating capillaries with necrosis of the intervening parenchyma. Minute foci of calcified necrosis were scattered in the deep subcortical white matter as well, while the ventricular ependyma and the subventricular germ cell layer remained remarkably intact. The cerebellum and brain stem appeared unaffected as well. Karyotyping of skin fibroblasts indicated a normal chromosome set of 46XY without gross structural anomalies. We interpret these findings as ones apt to being reasonably accommodated within the spectrum of MCA-RA. Although exceedingly rare, accurate identification of individual cases of MCA-RA is relevant both to differential diagnosis from its prognostically different look-alike "proliferative vasculopathy and hydranencephaly-hydrocephaly" (PVHH), and to refine the nosology of unconventional pediatric vascular malformations, for which the rather nonspecific label "angiodysgenetic necrotizing encephalopathy" is still commonly used.

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NPY receptors represent novel molecular therapeutic targets in cancer and obesity. However, the extent of NPY receptor expression in normal human tissues is poorly investigated. Based on the role of NPY in reproductive functions, the NPY receptor expression was studied in 25 normal human testes and, additionally, 24 testicular tumors using NPY receptor autoradiography. In the normal testis, Leydig cells strongly expressed NPY receptor subtype Y2, and small arterial blood vessels Y1. Y2 receptors were found to be functional with agonist-stimulated [(35)S]GTPγS binding autoradiography. Full functional integrity of the NPY system was further suggested by the immunohistochemical detection of NPY peptide in nerve fibers directly adjacent to Leydig cells and arteries. Germ cell tumors expressed Y1 and Y2 on tumor cells in 33% and Y1 on intratumoral blood vessels in 50%. Based on its strong NPY receptor expression in Leydig cells and blood vessels, the normal human testis represents a potentially important physiological and pharmalogical NPY target.

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Background Heterochromatin protein 1 (HP1) family proteins have a well-characterized role in heterochromatin packaging and gene regulation. Their function in organismal development, however, is less well understood. Here we used genome-wide expression profiling to assess novel functions of the Caenorhabditis elegans HP1 homolog HPL-2 at specific developmental stages. Results We show that HPL-2 regulates the expression of germline genes, extracellular matrix components and genes involved in lipid metabolism. Comparison of our expression data with HPL-2 ChIP-on-chip profiles reveals that a significant number of genes up- and down-regulated in the absence of HPL-2 are bound by HPL-2. Germline genes are specifically up-regulated in hpl-2 mutants, consistent with the function of HPL-2 as a repressor of ectopic germ cell fate. In addition, microarray results and phenotypic analysis suggest that HPL-2 regulates the dauer developmental decision, a striking example of phenotypic plasticity in which environmental conditions determine developmental fate. HPL-2 acts in dauer at least partly through modulation of daf-2/IIS and TGF-β signaling pathways, major determinants of the dauer program. hpl-2 mutants also show increased longevity and altered lipid metabolism, hallmarks of the long-lived, stress resistant dauers. Conclusions Our results suggest that the worm HP1 homologue HPL-2 may coordinately regulate dauer diapause, longevity and lipid metabolism, three processes dependent on developmental input and environmental conditions. Our findings are of general interest as a paradigm of how chromatin factors can both stabilize development by buffering environmental variation, and guide the organism through remodeling events that require plasticity of cell fate regulation.

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Insulin-like growth factor I (IGF-I) plays a key role in the complex system that regulates bony fish growth, differentiation, and reproduction. The major source of circulating IGF-I is liver, but IGF-I-producing cells also occur in other organs, including the gonads. Because no data are available on the potential production sites of IGF-I in gonad development, developmental stages of monosex breedings of male and female tilapia from 0 day postfertilization (DPF) to 90 DPF were investigated for the production sites of IGF-I at the peptide (immunohistochemistry) and mRNA (in situ hybridization) level. IGF-I mRNA first appeared in somatic cells of the male and female gonad anlage at 7 DPF followed by IGF-I peptide around 9-10 DPF. Gonad anlagen were detected from 7 DPF. Starting at 7 DPF, IGF-I peptide but no IGF-I mRNA was observed in male and female primordial germ cells (PGCs) provided that IGF-I mRNA was not under the detection level, this observation may suggest that IGF-I originates from the somatic cells and is transferred to the PGCs or is of maternal origin. While in female germ cells IGF-I mRNA and peptide appeared at 29 DPF, in male germ cells both were detected as late as at 51-53 DPF. It is assumed that the production of IGF-I in the germ cells is linked to the onset of meiosis that in tilapia ovary starts at around 28 DPF and in testes at around 52-53 DPF. In adult testis, IGF-I mRNA and peptide occurred in the majority of spermatogonia and spermatocytes as well as in Leydig cells, the latter indicating a role of IGF-I in the synthesis of male sex steroids. In adult ovary, IGF-I mRNA and IGF-I peptide were always present in small and previtellogenic oocytes but only IGF-I peptide infrequently occurred in oocytes at the later stages. IGF-I expression appeared in numerous granulosa and some theca cells of follicles at the lipid stage and persisted in follicles with mature oocytes. The results suggest a crucial role of local IGF-I in the formation, differentiation and function of tilapia gonads.

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BACKGROUND: To overcome the ototoxicity of cisplatin, single bolus infusions were replaced by repeated prolonged infusions of lower doses or by continuous infusions at still lower infusion rates. However, considering ototoxicity little is, in fact, known about the tolerance of repeated prolonged or continuous infusion in children. PROCEDURE: Auditory function was monitored along with plasma concentrations of free and total platinum (Pt), and with standard serum parameters (sodium, potassium, calcium, magnesium, phosphate, chloride, and creatinine) in 24 children receiving cisplatin by continuous infusion for the treatment of neuroblastoma and osteosarcoma or by repeated 1 or 6 hr infusions for the treatment of germ cell tumors. RESULTS: Hearing deteriorated in 10/15 osteosarcoma patients, 2/3 neuroblastoma patients, and 1/6 patients with germ cell tumors. Ototoxicity occurred after cumulative doses between 120 and 360 mg/m(2) cisplatin. In osteosarcoma patients, ototoxicity was associated with a comparatively higher mean plasma concentration of free Pt. However, Pt plasma concentrations did not discriminate between patients with or without ototoxicity. In patients experiencing ototoxicity serum creatinine increased by 45% compared to pre-treatment levels (mean). Serum creatinine increased by 26% in patients without ototoxicity (P < 0.05, Mann-Whitney Rank sum test). Despite standardized hydration, discrete but significant changes of potassium, sodium, magnesium, and phosphate were observed during and/or after cisplatin infusion, which, however, did not discriminate between patients with and without ototoxicity. CONCLUSIONS: While continuous cisplatin infusions are less nephrotoxic than repeated prolonged infusions, we observed considerable ototoxicity in patients treated with continuous cisplatin infusions, which necessitates further evaluations on the tolerance of continuous cisplatin infusions in children.

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To study the hypothesis that a delay in the diagnosis of paediatric brain tumours results in decreased survival outcome probability, we compared the prediagnostic period of 315 brain tumour patients (median age 6.7 years, range, 0 to 16 years) with progression-free and overall survival. The median prediagnostic symptomatic interval was 60 days (range, 0 to 3,480 days), with a median parental delay of 14 days (range, 0 to 1,835 days) and a median doctor's delay of 14 days (range, 0 to 3,480 days). The prediagnostic symptomatic interval correlated significantly with the patient age, tumour histology, tumour location and year of diagnosis, but not with gender. We then grouped the patients according to histology (low-grade glioma [n=77], medulloblastoma [n=57], high-grade glioma [n=40], craniopharyngioma [n=27], ependymoma [n=20] and germ cell tumours [n=18]). Contrary to common belief, long prediagnostic symptomatic interval or long doctor's delay did not result in decreased survival outcome probability in any of these groups. The effect of tumour biology on survival seems to be dominant and overwhelms any possible opposing effect on survival of a delay in diagnosis.

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Cisplatin, a major antineoplastic drug used in the treatment of solid tumors, is a known nephrotoxin. This retrospective cohort study evaluated the prevalence and severity of cisplatin nephrotoxicity in 54 children and its impact on height and weight.We recorded the weight, height, serum creatinine, and electrolytes in each cisplatin cycle and after 12 months of treatment. Nephrotoxicity was graded as follows: normal renal function (Grade 0); asymptomatic electrolyte disorders, including an increase in serum creatinine, up to 1.5 times baseline value (Grade 1); need for electrolyte supplementation <3 months and/or increase in serum creatinine 1.5 to 1.9 times from baseline (Grade 2); increase in serum creatinine 2 to 2.9 times from baseline or need for electrolyte supplementation for more than 3 months after treatment completion (Grade 3); and increase in serum creatinine ≥3 times from baseline or renal replacement therapy (Grade 4).Nephrotoxicity was observed in 41 subjects (75.9%). Grade 1 nephrotoxicity was observed in 18 patients (33.3%), Grade 2 in 5 patients (9.2%), and Grade 3 in 18 patients (33.3%). None had Grade 4 nephrotoxicity. Nephrotoxicity patients were younger and received higher cisplatin dose, they also had impairment in longitudinal growth manifested as statistically significant worsening on the height Z Score at 12 months after treatment. We used a multiple logistic regression model using the delta of height Z Score (baseline-12 months) as dependent variable in order to adjust for the main confounder variables such as: germ cell tumor, cisplatin total dose, serum magnesium levels at 12 months, gender, and nephrotoxicity grade. Patients with nephrotoxicity Grade 1 where at higher risk of not growing (OR 5.1, 95% CI 1.07-24.3, P=0.04). The cisplatin total dose had a significant negative relationship with magnesium levels at 12 months (Spearman r=-0.527, P=<0.001).

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Thymic stromal lymphopoietin (TSLP) is constitutively expressed in the intestine and is known to regulate inflammation in models of colitis. We show that steady-state TSLP expression requires intestinal bacteria and has an important role in limiting the expansion of colonic T helper type 17 (Th17) cells. Inappropriate expansion of the colonic Th17 cells occurred in response to an entirely benign intestinal microbiota, as determined following the colonization of germ-free C57BL/6 or TSLPR(-/-) mice with the altered Schaedler flora (ASF). TSLP-TSLPR (TSLP receptor) interactions also promoted the expansion of colonic Helios(-)Foxp3(+) regulatory T cells, necessary for the control of inappropriate Th17 responses following ASF bacterial colonization. In summary, these data reveal an important role for TSLP-TSLPR signaling in promoting steady-state mutualistic T-cell responses following intestinal bacterial colonization.