Aims
Incretin‐based therapies have been associated with an increased risk of pancreatitis. Recently, various histological abnormalities have been reported in human pancreatic tissue from brain‐dead ...organ donors who had been exposed to incretin‐based drugs. In the present study we examined pancreatic tissue collected at surgery.
Methods
Human pancreatic tissue from 7 type 2‐diabetic patients treated with incretin‐based drugs (type 2‐I), 6 diabetic patients without incretin treatment (type 2‐NI), 11 patients without diabetes (no diabetes group) and 9 brain‐dead organ donors (BDOD group) was examined.
Results
Fractional beta‐cell area was reduced in the type 2‐NI group compared to the group without diabetes (P < .05), but there was no difference compared to the type 2‐I patients. Alpha‐cell area (P = .30), beta‐cell replication (P = .17) and alpha‐cell replication (P = .91) were not different. There were also no differences in acinar cell (P = .13) and duct cell replication (P = .099). Insulin‐positive duct cells were more frequent in the type 2‐I and the BDOD groups (P = .034). No co‐expression of insulin and glucagon was detected. Pancreatic intraepithelial neoplasia (PanIN) lesions were very rare, all low‐grade (PanIN 1a and 1b) and tended to occur more frequently in the type 2‐I group (P = .084).
Conclusions
The present results did not reveal marked histological abnormalities in the pancreas of incretin‐treated patients with type 2 diabetes. Low numbers of specimens available and a large inter‐individual variability of the findings warrant caution regarding the interpretation of histological data concerning drug effects on the human pancreas.
Background: Reimplantations of autologous skull flaps after decompressive hemicraniectomies (DHs) are associated with high rates of postoperative bone flap resorption (BFR). We histologically ...assessed the cell viability of explanted bone flaps in certain periods of time after DH, in order to conclude whether precursors of BRF may be developed during their storage. Methods: Skull bone flaps explanted during a DH between 2019 and 2020 were stored in a freezer at either −23 °C or −80 °C. After their thawing process, the skulls were collected. Parameters of bone metabolism, namely PTH1 and OPG, were analyzed via immunohistochemistry. H&E stain was used to assess the degree of avital bone tissue, whereas the repeated assays were performed after 6 months. Results: A total of 17 stored skull flaps (8 at −23 °C; 9 at −80 °C) were analyzed. The duration of cryopreservation varied between 2 and 17 months. A relevant degree of bone avitality was observed in all skull flaps, which significantly increased at the repeated evaluation after 6 months (p < 0.001). Preservation at −23 °C (p = 0.006) as well as longer storage times (p < 0.001) were identified as prognostic factors for higher rates of bone avitality in a linear mixed regression model. Conclusions: Our novel finding shows a clear benefit from storage at −80° C, which should be carefully considered for the future management and storage of explanted skull flaps. Our analysis also further revealed a significant degree of bone avitality, a potential precursor of BFR, in skull flaps stored for several weeks. To this end, we should reconsider whether the reimplantation of autologous skull flaps instead of synthetic skull flaps is still justified.
The detection of plasma cell-free tumor DNA (ctDNA) is prognostic in colorectal cancer (CRC) and has potential for early prediction of disease recurrence. In clinical routine, ctDNA-based diagnostics ...are limited by the low concentration of ctDNA and error rates of standard next-generation sequencing (NGS) approaches. We evaluated the potential to increase the stability and yield of plasma cell-free DNA (cfDNA) for routine diagnostic purposes using different blood collection tubes and various manual or automated cfDNA extraction protocols. Sensitivity for low-level ctDNA was measured in
-mutant cfDNA using an error-reduced NGS procedure. To test the applicability of rapid evaluation of ctDNA persistence in clinical routine, we prospectively analyzed postoperative samples of 67 CRC (stage II) patients. ctDNA detection was linear between 0.0045 and 45%, with high sensitivity (94%) and specificity (100%) for mutations at 0.1% VAF. The stability and yield of cfDNA were superior when using Streck BCT tubes and a protocol by Zymo Research. Sensitivity for ctDNA increased 1.5-fold by the integration of variant reads from triplicate PCRs and with PCR template concentration. In clinical samples, ctDNA persistence was found in ∼9% of samples, drawn 2 weeks after surgery. Moreover, in a retrospective analysis of 14 CRC patients with relapse during adjuvant therapy, we successfully detected ctDNA (median 0.38% VAF; range 0.18-5.04% VAF) in 92.85% of patients significantly prior (median 112 days) to imaging-based surveillance. Using optimized pre-analytical conditions, the detection of postoperative ctDNA is feasible with excellent sensitivity and allows the prediction of CRC recurrence in routine oncology testing.
Aberrant Wnt-signaling caused by mutants of beta-catenin, a key regulator of the canonical Wnt-signaling pathway, is frequently detected in cancer. Only recently, it was suggested that in ...hepatocellular carcinoma (HCC) the expression of the target gene glutamine synthetase (GS) is a highly reliable marker for the identification of beta-catenin mutations. In order to prove this hypothesis, 52 samples from human hepatocellular carcinomas were analysed for the activation of beta-catenin and the expression of GS. In total, 45 samples stained positive for cytoplasmic/nuclear beta-catenin. A strong correlation between expression of GS and activated beta-catenin (100% of nuclear and 84% of cytosolic) was found. However, among 35 GS positive tumors that were analysed for beta-catenin mutations no mutations were detected in 25 GS-positive carcinomas although 24 out of the 25 carcinomas exhibited at least abnormal expression of beta-catenin. Since the mutational analysis identified 9 different point mutations of the beta-catenin gene including the rare mutation H36P and the yet unknown mutation P44A it was asked whether these mutations may differently effect beta-catenin target genes. Therefore, expression plasmids for different mutations were constructed and cotransfected with the TOP-flash luciferase reporter and a reporter carrying the GS-5'-enhancer. The experiments confirmed that there are differences between different beta-catenin target sequences and different beta-catenin mutations. In addition, the failure that the endogenous expression of GS in GS-negative cells was not induced by the transient transfection experiment indicated that the effect of beta-catenin on the GS-5'-enhancer is only one aspect of gene activation induced by beta-catenin.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The suppressors of cytokine signaling (SOCS) are inhibitors of cytokine signaling that function via the Janus kinase (JAK)/signal transducers and activators of transcription (STAT) pathway. Recently, ...methylation of SOCS-1 and SOCS-3 has been implicated in the tumorigenesis of liver and lung cancer. This study was performed to elucidate the role of SOCS-1 and SOCS-3 in squamous cell carcinoma of the head and neck (HNSCC) and its precursor lesions. HNSCC of 94 patients and corresponding normal mucosa, lymph node metastases as well as 16 high- and 21 low-grade squamous cell dysplasias were studied by using methylation-specific PCR (MSP) for the SOCS-1 and SOCS-3 promoter after microdissection. The presence of SOCS-3 mRNA transcripts was confirmed by semiquantitative real-time PCR, and the SOCS-3 protein was analysed immunohistochemically. SOCS-3 hypermethylation was found in 85/94 HNSCC (90%) and in 10/16 high-grade and 9/21 low-grade dysplasias (63 and 43%, respectively). SOCS-1 promoter hypermethylation was detected in 10/94 HNSCC samples (11%) and in 2/16 high-grade and 1/21 low-grade dysplasias (13 and 5%, respectively). Lymph node metastases exhibited an identical methylation status as the primary tumors. Methylation of the SOCS-3 promoter correlated with downregulation of SOCS-3 transcripts and protein expression in these tumors and various cell lines. In the cell lines tested, SOCS-3 and SOCS-1 transcripts increased upon treatment with the demethylation compound 5-aza-2-deoxycytidine (5-AZA-DC). Overexpression of wild-type SOCS-3 in carcinoma cells with methylated SOCS-3 resulted in the induction of apoptosis and growth suppression as well as downregulation of STAT3, bcl-2 as well as bcl-xL. Our data suggest that promoter methylation and subsequent transcript downregulation of SOCS-3 transcripts and, to a much lesser extent, SOCS-1 are involved in the multistep carcinogenesis of HNSCC. During its involvement in tumor growth, restoration of SOCS-3 may hold treatment potential for HNSCC.
A malignant ureteral obstruction is most often due to primary tumors of the ureter. However, it can occur secondary due to external tumor compression or metastatic infiltration. Distant metastases to ...the ureter are extremely rare. We present a case of a rare double distant metachronic metastasis to the right ureter as well as to the right renal pelvis in a 58-year-old female with a history of anterior resection for rectal cancer 2 years earlier. She presented with recurrent urinary tract infection and right hydronephrosis caused by an ureteral mass. The patient underwent a right nephroureterectomy via laparotomy. Two metastases of the rectal cancer in the ureteral mucosa were verified at histology. On account of the infiltration of the right ureteral orifice, a completion transurethral resection of the tumor was performed. A follow-up 3 and 6 months later showed no signs of tumor relapse and the patient was doing well. The differential diagnosis of malignant ureteral obstruction in patients with history of colorectal cancer should include the rare possibility of distant metastasis from the primary tumor.
We aimed to assess for the first time the mismatch repair (MMR) protein expression in Merkel cell carcinoma (MCC). Immunohistochemistry was performed for MLH1, MSH2, MSH6, and PMS2 on patients’ tumor ...tissue (n = 56), including neighbored healthy control tissue. In cases with low-level MMR expression (<10th percentile), we performed multiplex PCR in combination with high-resolution capillary electrophoresis in order to confirm microsatellite instability (MSI). Microscopic evaluation revealed a high median expression for all MMR proteins studied (91.6–96.3%). However, six patients (56/10.7%) had low-level MLH1 expression, six (55/10.9%) had low-level MSH2 expression, five (56/8.9%) had low-level MSH6 expression, and six (54/11.1%) had low-level PMS2 expression. Together, we observed nine (56/16.1%) patients who had low-level MMR expression of at least one protein. Of the patients with low-level MMR expression, MSI evaluation was possible in five cases, revealing one case with high-level MSI. In all MMR proteins assessed, low-level expression was significantly (p = 0.0004 to p < 0.0001) associated with a negative Merkel cell polyomavirus (MCPyV) status. However, the expression profiles of the MMR proteins did not correlate with clinical outcome measures such as disease relapse or death (p > 0.05). MCC appears to be a malignancy characterized by low-level MMR rather than completely deficient MMR in a subset of cases, predominantly affecting MCPyV-negative tumors. Future studies will establish whether this subset of MCC patients respond better to immune checkpoint inhibitor therapy.
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