454 research outputs found
Autopsy of Adult Patients Deceased in an Academic Hospital: Considerations of Doctors and Next-of-Kin in the Consent Process
Detection of human endogenous retrovirus type K-specific transcripts in testicular parenchyma and testicular germ cell tumors of adolescents and adults: clinical and biological implications
Testicular germ cell tumors (TGCTs) of adolescents and adults have been
shown to contain proteins of the human endogenous retrovirus type K
family. In a recent study, expression of these retroviral sequences was
confirmed using in situ hybridization, which also showed expression in
carcinoma in situ, the precursor of all TGCTs. Because of the clinical
significance of a test for early diagnosis of TGCTs, we studied whether
expression of human endogenous retrovirus type K genes could be an
informative parameter. Therefore, we investigated TGCTs of various
histologies and testicular parenchyma with and without carcinoma in situ
using reverse transcription-polymerase chain reaction for expression of
the gag, env, and prt genes. The gag and prt genes were expressed in all
samples tested. The env transcripts were not found in TGCTs showing
somatic differentiation only but could be detected in most normal
testicular parenchyma samples. Therefore, detection of human endogenous
retrovirus type K transcripts cannot be used for early diagnosis of TGCTs.
Simultaneous expression of multiple gag sequences was found both in normal
parenchyma and TGCTs, and we demonstrated that expression of gag sequences
with an extra G, necessary to generate a functional protein, was not
limited to TGCTs
Heterogeneous X inactivation in trophoblastic cells of human full-term female placentas
In female mammalian cells, one of the two X chromosomes is inactivated to
compensate for gene-dose effects, which would be otherwise doubled
compared with that in male cells. In somatic lineages in mice, the
inactive X chromosome can be of either paternal or maternal origin,
whereas the paternal X chromosome is specifically inactivated in placental
tissue. In human somatic cells, X inactivation is mainly random, but both
random and preferential paternal X inactivation have been reported in
placental tissue. To shed more light on this issue, we used PCR to study
the methylation status of the polymorphic androgen-receptor gene in
full-term human female placentas. The sites investigated are specifically
methylated on the inactive X chromosome. No methylation was found in
microdissected stromal tissue, whether from placenta or umbilical cord. Of
nine placentas for which two closely apposed samples were studied, X
inactivation was preferentially maternal in three, was preferentially
paternal in one, and was heterogeneous in the remaining five. Detailed
investigation of two additional placentas demonstrated regions with
balanced (1:1 ratio) preferentially maternal and preferentially paternal X
inactivation. No differences in ratio were observed in samples
microdissected to separate trophoblast and stromal tissues. We conclude
that methylation of the androgen receptor in human full-term placenta is
specific for trophoblastic cells and that the X chromosome can be of
either paternal or maternal origin
Molecular determinants of treatment response in human germ cell tumors
PURPOSE: Germ cell tumors (GCTs) are highly sensitive to cisplatin-based
chemotherapy. This feature is unexplained, as is the intrinsic
chemotherapy resistance of mature teratomas and the resistant phenotype of
a minority of refractory GCTs. Various cellular pathways may influence the
efficacy of chemotherapy. Their impact has not been investigated in a
comprehensive study of tumor samples from clinically defined subgroups of
GCT patients. EXPERIMENTAL DESIGN: We investigated proteins involved in
regulation of apoptosis (p53, BAX, BCL-2, and BCL-X(L)), cell cycle
control [p21 and retinoblastoma protein (RB)], and drug export and
inactivation [P-glycoprotein, multidrug resistance-associated protein
(MRP) 1, MRP2, breast cancer resistance protein, lung resistance protein,
metallothionein, and glutathione S-transferase pi] immunohistochemically
in samples of unselected GCT patients (n = 20), patients with advanced
metastatic disease in continuous remission after first-line chemotherapy
(n = 12), and chemotherapy-refractory patients (n = 24). Mature teratoma
components (n = 10) within tumor samples from all groups were analyzed
separately. The apoptotic index was studied by terminal deoxynucleotidyl
transferase-mediated nick end labeling assay. RESULTS: Invasive GCTs of
all groups showed a correlation between wild-type p53 and apoptotic index
(r(s) = 0.66; P < 0.001). The levels of the antiapoptotic proteins BCL-2
and BCL-X(L) were generally low. p21 was hardly detectable and did not
correlate with p53 (r(s) = 0.29; P = 0.07). No significant differences
among the three patient groups were identified regarding any of the
investigated parameters (all Ps were >0.08), even though only individual
samples from chemotherapy-resistant cases showed a strong staining for
MRP2 and GSTpi. In contrast to other components, mature teratomas showed
an intense p21 and RB staining and were mostly positive for MRP2, lung
resistance protein, and GSTpi. CONCLUSIONS: Our results indicate a
multifactorial basis for the chemosensitivity of GCTs with lack of
transporters for cisplatin, of antiapoptotic BCL-2 family members, of p21
induction by p53, and of RB and an intact apoptotic cascade downstream of
p53. These findings suggest a preference for apoptosis over cell cycle
arrest after up-regulation of p53. None of the examined parameters offers
a general explanation for the chemotherapy-resistant phenotype of
refractory tumors. The up-regulation of various factors interfering with
chemotherapy efficacy and ability for a p21-induced cell cycle arrest may
explain the intrinsic chemotherapy resistance of mature teratomas
Cytogenetic evidence that carcinoma in situ is the precursor lesion for invasive testicular germ cell tumors
N- and KRAS mutations in primary testicular germ cell tumors: Incidence and possible biological implications
Recently, conflicting results have been reported on the incidence of RAS mutations in primary testicular germ cell tumors of adults (TGCTs). In four studies a low incidence of mutations (less than 15%) in a variety of TGCTs or derived cell lines was found, whereas in two other studies a high incidence of N- or KRAS mutations (over 40%) was shown. A total of 62 testicular seminomas (SE) and 34 nonseminomatous TGCTs (NS) were studied thus far. The largest series consisted of 42 TGCTs, studied on paraffin embedded tissue. We present the results of analysis for the presence of N- and KRAS mutations, in codons 12, 13, and 61, in snap frozen samples of 100 primary TGCTs, comprising 40 SE and 60 NS. Using the polymerase chain reaction (PCR) and allele specific oligonucleotide hybridization (ASO), mutations were found in five SE (three in NRAS and two in KRAS, all codon 12), and in one NS (KRAS, codon 12). To exclude underestimation of the incidence of RAS mutations in TGCTs due to the presence of an excess of wild type alleles in the analyzed sample, a PCR technique preferentially ampli
Post-mortem tissue biopsies obtained at minimally invasive autopsy: An RNA-quality analysis
Introduction: Bereaved relatives often refuse to give consent for post-mortem investigation of deceased cancer patients, mainly because of the mutilation due to conventional au
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