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Liraglutide is a new generation lipopeptide drug used for the treatment of type II diabetes. In this work, we describe new approaches for its preparation fully by chemical methods. The key step of these strategies is the synthesis in solution of the Lys/γ-Glu building block, Fmoc-Lys-(Pal-γ-Glu-OtBu)-OH, in which Lys and Glu residues are linked through their side chains and γ-Glu is Nα-palmitoylated. This dipeptide derivative is then inserted into the peptide sequence on solid phase. As liraglutide is obtained with great purity and high yield, our approach can be particularly attractive for an industrial production. We also report here the results of a circular dichroism conformational analysis in a membrane mimetic environment that offers new insights into the mechanism of action of liraglutide. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd

Background: Current surgical standard of care in sporadic medullary thyroid carcinoma (sMTC) consists of a minimum of total thyroidectomy with central neck dissection. Some have suggested thyroid lobectomy with isthmusectomy and central neck dissection for patients with sMTC, given their lower frequency of bilateral disease, although this topic has not been thoroughly studied. This study assessed the prevalence of multifocality in sMTC via a large international multi-institutional retrospective review to quantify this prevalence, including the impact of geography, to assess more accurately the risks associated with alternative surgical approaches. Methods: A retrospective chart review of sMTC patients from 11 institutions over 29 years (1983-2011) was undertaken. Data regarding focality, extent of disease, RET germline analysis plus family and clinical history for multiple endocrine neoplasia type 2 (MEN2), and demographic data were collected and analyzed. Results: Patients from four continents and seven countries were included in the sample. Data for 313 patients with documented sMTC were collected. Of these, 81.2% were confirmed with negative RET germline testing, while the remaining 18.8%demonstrated a negative family history and nomanifestations ofMEN2 syndromes other thanMTC. Bilateral disease was identified in 17/306 (5.6%) patients, while multifocal disease was noted in 50/312 (16.0%) sMTC patients. When only accounting for germline negative patients, these rates were not significantly different (5.6% and 17%, respectively). Among them, when disease was unifocal in the ipsilateral lobe and isthmus, bilateral disease was present in 6/212 (2.8%) cases. When disease was multifocal in the ipsilateral lobe or isthmus, then bilateral disease was present in 8/37 (21.6%) cases ( p < 0.001). No geographic differences in focality were identified. Conclusions: The 5.6% prevalence of bilateral foci in sMTC suggests that total thyroidectomy should remain the standard of care for initial surgery, as less complete thyroid surgery may fail to address fully the primary site of disease. Whether ipsilateral tumor focality should be an independent factor determining the need for completion thyroidectomy when sMTC is diagnosed after hemithyroidectomy remains to be determined.

Objectives: The purpose of this study was to examine the effect of cyclization on the biological profiles of [99mTcN(PNP3)]-labeled α-MSH analogs. Methods: The linear peptide H-Cys-Ahx-bAla-Nle-Asp-His-D-Phe-Arg-Trp-Gly-NH2 (NAP-NS1) (1) and a corresponding lactam bridge-cyclized peptide, H-Cys-Ahx-bAla3-c[Lys4-Glu-His-D-Phe-Arg-Trp-Glu10]-Arg11-Pro-Val-NH2 (NAP-NS2) (2), were synthesized, characterized by ESI-MS, and their melanocortin-1 receptor (MC1R) binding affinity was determined in B16F10 melanoma cells. In vitro stability and pharmacological parameters of [99mTc(N)(NAP-NS1)(PNP3)]+ (1a) and [99mTc(N)(NAP-NS2)(PNP3)]+ (2a) were assessed. Challenges with an excess of glutathione and cysteine and LogD values were also investigated. Furthermore, 1a and 2a were applied to study in vivo stability and the pharmacokinetic profiles on healthy rats. Results: 1a and 2a were obtained in high yield (RCY > 90%). LogD values demonstrated the hydrophilic nature of the radiolabeled peptides: -1.43 for 1a; - 2.09 for 2a. No significant variations in RCPs of both the complexes were observed. Both complexes showed high stability after incubation in human and rat sera as well as in rat liver homogenate. A fast degradation of 2a was detected in kidneys homogenate. 1a retained a high receptor affinity (Kd: 7.1±0.5 nM). Biodistribution of 1a displayed a favorable pharmacokinetic profile with fast blood clearance and elimination from normal tissues. Rapid renal excretion of 1a was observed due to the high hydrophilic character. The pharmacokinetic profile of 2a was reflected in reduction of the blood clearance and the elimination from the other organs; especially the kidneys showed restraint elimination. Conclusions: Compared with the linear peptide 1, cyclization affected the pharmacological properties of 2 negatively by reducing its stability, its binding affinity to MC1Rs (Ki: 0.9±0.3 nM for 1; 7.1±2.4 nM for 2) and decreasing the overall excretion rate of the corresponding [99mTcN(PNP3)]-labeled peptide from the body. Thus, only the linear labeled peptide 1a will be considered for further investigations in tumor bearing mice.

L’articolo fa un confronto tra le differenti forme urbane delle città del Nord Africa, in particolare quelle della Tunisia (Tunisi, Kairouan, Tozeur, Nefta). Tali città, distribuite tra il Nord ed il Sud del paese, esprimono, nelle loro medine, l’identità della forma urbana e ne dichiarano la modernità lungo i loro bordi. Tunisi, posta tra due laghi, costruisce la sua modernità con la città coloniale che, anche se con linguaggi diversi, evidenzia i temi del Mediterraneo. La città di Kairouan mantiene la sua identità nella grande moschea, luogo centrale di organizzazione urbana. Le città d’oasi, come Tozeur e Nefta, esprimono il loro rapporto col paesaggio ed evidenziano con le loro architetture i materiali usati.

Objectives: To evaluate the diagnostic accuracy of fine-needle aspiration biopsy (FNAB) to preoperatively diagnose medullary thyroid cancer (MTC) among multiple international centers and evaluate how the cytological diagnosis alone could impact patient management.Methods: We performed a retrospective chart review of sporadic MTC (sMTC) patients from 12 institutions over the last 29 years. FNAB cytology results were compared to final pathologic diagnoses to calculate FNAB sensitivity. To evaluate the impact of cytology sensitivity for MTC according to current practice and to avoid confounding results by local treatment protocols, changes in treatment patterns over time, and the influence of ancillary findings (e.g., serum calcitonin), therapeutic interventions based on FNAB cytology alone were projected into 1 of 4 treatment categories: total thyroidectomy (TT) and central neck dissection (CND), TT without CND, diagnostic hemithyroidectomy, or observation.Results: A total of 313 patients from 4 continents and 7 countries were included, 245 of whom underwent FNAB. FNAB cytology revealed MTC in 43.7% and possible MTC in an additional 2.4%. A total of 113 (46.1%) patients with surgical pathology revealing sMTC had FNAB findings that supported TT with CND, while 37 (15.1%) supported TT alone. In the remaining cases, diagnostic hemithyroidectomy and observation were projected in 32.7% and 6.1%, respectively.Conclusion: FNAB is an important diagnostic tool in the evaluation of thyroid nodules, but the low sensitivity of cytological evaluation alone in sMTC limits its ability to command an optimal preoperative evaluation and initial surgery in over half of affected patients. © 2013 AACE.

Background: There is increasing evidence that changes in thyroid function are associated with obesity, a condition associated with a chronic low-grade state of inflammation. Meanwhile, recent data have disclosed a relation between obesity and thyroid autoimmunity, with the adipocyte hormone leptin appearing to be the key factor linking these two conditions. Summary: Leptin has variably been implicated in thyroid function, while recent findings suggest that leptin resistance may mitigate leptin deficiency and enhance autoimmunity in obese subjects via mechanisms operating independently of thyroid function. The development of resistance to the weight-lowering effects of leptin in obesity might well be initiated by activation of inflammatory signaling, which substantially contributes to the derangement of immune response and propagation of autoimmunity in susceptible individuals. Conclusions: Regulation of inflammasome-derived cytokines in obesity is an important step in controlling the trigger of thyroid autoimmunity. The clarification of the pathways may offer innovative therapeutic targets in obesity and thyroid autoimmunity. © Copyright 2013, Mary Ann Liebert, Inc. 2013.

Esculentins-1 are a family of frog skin antimicrobial peptides (AMPs), characterized by a 46 amino acids primary structure and a broad range of antimicrobial activity. Studies on the mode of action of amphibian AMPs evidenced that bacterial membranes are their major target. Esculentins possess the basic features common to most linear AMPs, that is an overall positive charge at neutral pH and a considerable proportion of hydrophobic residues. These properties allow the peptides to bind to the negatively-charged microbial membranes by folding into an amphiphilic structure, thus perturbing membrane permeability. Esculentin 1-21 [Esc(1-21)], consists of the first 20 aminoacids of the naturally occurring Esculentin 1a, with a glycinamide residue at the C-terminus: H-Gly-Ile-Phe-Ser-Lys-Leu-Ala-Gly-Lys-Gly-Leu-Lys-Asn-Leu-Leu-Ile-Ser-Gly-Leu-Lys-Gly-NH2. It was previously demonstrated that Esc(1-21) is highly potent against the most common mastitis-causing microbes in dairy cattle (e.g. Streptococcus agalactiae) both in vitro and in vivo. Furthermore, recent studies have indicated that this peptide can rapidly kill both planktonic and biofilm forms of the opportunist pathogen Pseudomonas aeruginosa and improve survival in a murine model of Pseudomonas lung infection upon its topical administration. These properties make Esc(1-21) an attractive starting point for the development of novel antimicrobial agents able to cure mastitis in dairy cows and to treat Pseudomonas-related infections. Current therapies in clinical and veterinary medicine suffer from drawbacks that include the increased emergence of multidrug-resistant pathogens, and the production of milk contaminated with antibiotics has become a serious threat in the livestock. In this connection, we thought significant to explore the effects of the incorporation of ?-aminoisobutyric acid (Aib) residues into the sequence of Esc(1-21). When inserted into peptides, this strongly helicogenic, non-coded, C?-tetrasubstituted ?-amino acid might increase the population and stability of helical structures and also potentially confer resistance against enzymatic degradation. In this work we report on the synthesis, the characterization, a preliminary conformational study in different environments by CD and 2D-NMR techniques, and the biological activity of an analog of Esc(1-21) bearing three residues of ?-aminoisobutyric acid (Aib) at sequence position 1, 10 and 18.

Synthetic peptides represent first choice biomelecules, with respect to proteins and mAb, for the monitoring of population variability and receptor functionality associated to a tumor pathology due to their favorable pharmacokinetic profile. It has been demonstrated that the surface molecule integrin alfa-V beta-3 could be an ideal target for the interaction with melanoma directed radiolabeled peptides.....

The medium-length peptaibiotics are characterized by a primary structure of 14-16 amino acid residues. Despite the interesting antibiotic and antifungal properties exhibited by these membrane-active peptides, their exact mechanism of action is still unknown. Here, we present our results on heptaibin, a 14-amino acid peptaibiotic found to exhibit antimicrobial activity against Staphylococcus aureus. We carried out the very challenging synthesis of heptaibin on solid phase and a detailed conformational analysis in solution. The peptaibiotic is folded in a mixed 3(10)-/alpha-helix conformation which exhibits a remarkable amphiphilic character. We also find that it is highly stable toward degradation by proteolytic enzymes and nonhemolytic. Finally, fluorescence leakage experiments using small unilamellar vesicles of three different compositions revealed that heptaibin, although uncharged, is a selective compound for permeabilization of model membranes mimicking the overall negatively charged surface of Gram-positive bacteria. This latter finding is in agreement with the originally published antimicrobial activity data.