SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Stålberg Peter Docent) "

Sökning: WFRF:(Stålberg Peter Docent)

  • Resultat 1-5 av 5
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Norlén, Olov (författare)
  • Small Intestinal Neuroendocrine Tumor : A Rare Malignancy with Favorable Outcome
  • 2013
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • Small intestinal neuroendocrine tumor (SI-NET) is the most common small bowel tumor in Europe and USA, with an annual incidence of around 0.3-1.3/100000 persons. SI-NETs are the most common type of gastroenteropancreatic NETs (GEP-NETs), and they are known for their ability to produce hormones such as tachykinins and serotonin, as well as for their favorable long-term prognosis in comparison to gastrointestinal adenocarcinoma. The overall aim of the thesis was to investigate unknown or unclear aspects of SI-NET disease, in connection with prognosis, treatment and follow-up. Paper I confirmed several known negative prognostic factors and also showed, for the first time, that para-aortal lymph node metastases and peritoneal carcinomatosis were associated with worse survival by multivariable analyses. Locoregional surgery was associated with a low post-operative mortality, and a prolonged long-term survival by multivariable analysis. In Paper II we continued to investigate peritoneal carcinomatosis and found it be a risk factor not only for death, but also for emergency re-surgery. Furthermore, genetic analyses of samples from primary tumors in patients with and without peritoneal carcinomatosis showed a difference in the DNA between these two groups. In Paper III the outcome after liver surgery and/or radiofrequency ablation of liver metastases was investigated. To summarize, no difference in survival was seen in patients treated with surgery/radiofrequency ablation in comparison with matched controls. However, a superior radiological response of liver metasases and lower U-5-HIAA values were seen in patients subjected to liver surgery and/or radiofrequency ablation compared to matched controls. Paper IV compared ultrasonography, computed tomography and 11C-5HTP-PET in the follow-up after radiofrequency ablation of NET liver metastases. The study concluded that 11C-5HTP-PET depicted all residual tumors after RFA and that it, if used, should be combined with computed tomography for easier interpretation, as RFA areas are not clearly distinguishable with 11C-5HTP-PET alone. Paper V studied gallstone complications after somatostatin analog treatment in SI-NET patients, and concluded that there was a rather high risk to be subjected to a cholecystectomy due to biliary colic, cholecystitis, cholangitis or pancreatitis after primary surgery in somatostatin analog treated patients.
  •  
2.
  • Annerbo, Maria, 1967- (författare)
  • Calcium Homeostasis in Patients with Graves' Disease
  • 2016
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • Patients with Graves´ Disease (GD) have a higher risk of developing more severe and prolonged hypocalcaemia after total thyroidectomy (TT) than patients who undergo surgery for benign atoxic goitre. Since TT is the most effective treatment for GD, it is crucial to identify mechanisms for postoperative hypocalcaemia. The aim of this thesis was to study the mechanisms of calcium metabolism in patients with GD.It is safe to operate on GD patients with TT. Results in Paper I showed fewer recurrences and equal complication rates compared to patients who underwent subtotal thyroidectomy (ST). The transient lowering of PTH seen in the hypocalcaemic patients was fully restored one month after surgery (Papers II and V).The calcium-sensing receptor (CaSR) is crucial for maintaining plasma calcium, and single nucleotide polymorphisms (SNPs) in the gene may alter the sensing function. Thus, we analysed SNPs in CaSR in GD patients (Paper II) and showed that they had a more left-shifted calcium-PTH set-point compared to controls, implicating higher sensitivity. This is also supported by the results in the group of postoperatively hypocalcaemic patients. They already had lower plasma calcium preoperatively (Papers II, IV and V) and lacked the T/G G/A G/C, a haplotype shown in Paper III to have a close relationship to higher p-calcium levels. Moreover, a lack of the T allele in rs1801725 was seen in the group of patients needing permanent treatment with calcium and vitamin D, i.e. > 12 months, (paper V).Patients who became hypocalcaemic (p-calcium < 2.00 mmol/L) on day one postoperatively, had lower preoperative levels of thyroid stimulating hormone (TSH) and higher levels of  T3, this was also applied to the patient groups requiring temporary or permanent postoperative treatment (Papers II and V). In addition, hypocalcaemic patients treated for less than six months with anti-thyroid drugs had higher levels of bone metabolism markers CTX and P1NP than normocalcaemic patients (Paper V).In conclusion, the postoperative period of hypocalcaemia seen in patients with GD is a complex medical condition, caused by a combination of surgical trauma, different SNPs in CaSR, and high bone metabolism related to preoperative thyroid metabolism.
  •  
3.
  • Halin Lejonklou, Margareta, 1966- (författare)
  • The MEN 1 Pancreas : Tumor Development and Haploinsufficiency
  • 2012
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • Multiple Endocrine Neoplasia Type I Syndrome (MEN 1) is a monogenic autosomal dominantly inherited cancer syndrome caused by a heterozygous loss of the MEN1 gene, predisposing for endocrine cell proliferation and tumor formation. MEN 1 carriers classically develop tumors in endocrine organs; the parathyroids, the endocrine pancreas, and the pituitary. Other organs, endocrine and non-endocrine, may also be affected. The most common cause of death in MEN 1 is pancreatic endocrine tumor (PNET), which exhibit inactivation of both MEN1 alleles. The increased proliferation prior to loss of the wild-type allele indicates haploinsufficiency, and little is known concerning the mechanisms behind MEN 1 PNET development. The MEN1 protein, menin, lacking homology with other known proteins, is involved in several aspects of transcriptional regulation and chromatin organization.We report differential expression and subcellular localization of transcription factors important in pancreatic development, in human and mouse MEN 1 pancreas, compared to non-MEN 1 pancreas. A predominantly cytoplasmic localization of Neurogenin3 and NeuroD1 was observed in tumors as well as in MEN 1 non-tumorous pancreas.Notch signaling factor expression and localization were examined in the pancreas of a heterozygous Men1 mouse model, and compared with that of wild-type littermates. Nuclear Hes1 was lost in tumors, concomitant to weaker Notch1 NICD expression, and further, analyzed using qPCR, it was shown that Notch1 was less expressed in heterozygous islets compared to wild-type islets.Performing a global gene expression array, we identified differential gene expression in five-week-old heterozygous Men1 mouse islets, compared to islets from wild-type littermates. The array results for a subset of the differentially regulated genes were corroborated using qPCR, western blotting and in situ PLA. We additionally observed significantly accelerated proliferation in islets from young heterozygous animals.It is often problematic to determine prognosis for individual patients with PNET. This is especially true in the group of patients with well differentiated endocrine carcinomas. In the absence of metastases, morphological signs of malignancy are frequently lacking. We evaluated the expression of nuclear and cytoplasmic survivin in a clinically characterized patient material (n=111), and a high nuclear survivin expression proved to be a significant negative prognostic factor for survival.
  •  
4.
  • Karakatsanis, Andreas, 1980- (författare)
  • Sentinel Node Biopsy for Breast Cancer : Aspects and evolution
  • 2018
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • Sentinel Node Biopsy (SNB) in clinical practice was pivotal to the shaping of modern diagnosis, staging and treatment of patients with breast cancer. The use of radioisotope (RI) and blue dye (BD) has led to high detection rates with low false negatives, but delivery-of-care limitations connected to these tracers as well as the need for methods addressing new clinical conundrums delineates the urge for new tracers with comparable performance, easier logistics and, ideally expanded implementations. Aim of the present thesis is to examine the outcomes of Superparamagnetic Iron Oxide (SPIO) nanoparticles, a new tracer based on magnetism for the detection of the sentinel nodes.Paper I is a prospective multicentre trial comparing SPIO to RI+BD, with all tracers injected at the same patient. In 206 patients, SPIO had a similar detection rate (97.6 vs 97.1%, p=0.76) whereas concordance between methods was 98%. The study was completed by a meta-analysis of similar trials published until that point. The detection rates were comparable (fixed OR:1.10; 0.67,1.79, p=0.71), and so was concordance between tracers (fixed RD: 0.00; -0.01, 0.01, p=0.82). Discoloration was present after periareolar SPIO injection in 39% of patients, almost exclusively treated with breast conservation, which reduced to 8.6% after 15 months of follow-up.Paper II was a pilot study of twelve patients with breast cancer and SNB performed where SPIO and the combination of RI+BD were injected, but SPIO was injected up to 15 days preoperatively, with total success in detection and complete concordance.Paper III tested the performance of SPIO as a sole tracer in a pragmatic double-arm non-randomised trial comparing it to the combination of RI+BD. Detection was 95.7% for SPIO and 96.8% for RI (p = 0.59). The preoperative injection of SPIO (1-27 d) enhanced SPIO specific detection (95.7 vs 86%, p=0.002).Paper IV is an interim analysis of a multicentre cohort study including patients with high-risk DCIS planned for breast conservation or any DCIS planned for mastectomy. SPIO was injected to “mark” the sentinel node but SNB was performed in a second operation only if invasive cancer was found at the first operation. In 151 included patients, this technique led to avoidance of 81.5% SNB, with a cost reduction of 14.1% for the entire cohort and 25.8% for the patients that did not have invasive cancer. The detection rate at reoperation was superior for SPIO and comparable with SNB detection at primary operation.In conclusion, SPIO is a novel tracer for SNB in breast cancer with comparable performance, fit for performance in a global setting and with wider clinical implementations compared to RI+BD.
  •  
5.
  • Nordeman, Patrik, Docent, et al. (författare)
  • 18F-Radiolabeling and Preliminary Evaluation of a HSP90 ligand
  • 2021
  • Ingår i: European Journal of Pharmaceutical Sciences. - : Elsevier. - 0928-0987 .- 1879-0720. ; 157
  • Tidskriftsartikel (refereegranskat)abstract
    • PURPOSE: With the ambition of improving the management of pancreatic neuroendocrine tumors (P-NETs), we developed and preliminary validated a novel fluorine-18 labelled HSP90 ligand.METHODS: A precursor containing methoxymethyl ethers protecting groups and a tosyl as leaving group was synthesized. The target compound was labeled with nucleophilic 18F-fluoride and the protecting groups was subsequently removed with hydrochloric acid before purification. In vitro cell- and frozen section autoradiography and in vivo animal studies were performed.RESULTS: The precursor was successfully synthesized and utilized in the 18F-radiolabeling giving 0.5-1.0 GBq of pure product with a synthesis time of 70 min. In vitro experiments indicated a high specific binding, but in vivo studies showed no tumor uptake due to fast hepatobiliary metabolism and excretion.CONCLUSIONS: Despite the unfavorable in vivo properties of the tracer, the promising results from in vitro autoradiography experiments in frozen sections of P-NETs from surgical resection encourage us to continue the project aiming the improvement of in vivo properties of the tracer.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-5 av 5

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy