Temporal bone verrucous carcinoma: outcomes and treatment controversy

Verrucous carcinoma is a rare tumor that presents in the head and neck with the most common sites being the oral cavity and larynx. Fourteen cases of verrucous carcinoma of the temporal bone have been described in literature; this study aims to examine treatment outcomes and discuss the controversy surrounding postoperative radiation. The study design included a literature review along with individual case report in the setting of a tertiary care medical center. Outcome analysis of all cases of verrucous carcinoma of the temporal bone, which are documented in the English literature, and presentation of a single patient report including gross, histologic and radiologic analyses were performed. The longest recorded survival for verrucous carcinoma of the temporal bone occurs in patients treated with surgery alone. Poorer outcomes for patients treated with adjuvant (chemo)radiation may be due to more advanced stage of disease at the time of treatment. Early reports of radiation leading to tumor dedifferentiation or early recurrence are not supported by more recent studies. Whether adjuvant radiation therapy is indicated in verrucous carcinoma of the temporal bone remains controversial

Organ preservation surgery for laryngeal cancer

The principles of management of the laryngeal cancer have evolved over the recent past with emphasis on organ preservation. These developments have paralleled technological advancements as well as refinement in the surgical technique. The surgeons are able to maintain physiological functions of larynx namely speech, respiration and swallowing without compromising the loco-regional control of cancer in comparison to the more radical treatment modalities. A large number of organ preservation surgeries are available to the surgeon; however, careful assessment of the stage of the cancer and selection of the patient is paramount to a successful outcome. A comprehensive review of various organ preservation techniques in vogue for the management of laryngeal cancer is presented

ICAR: endoscopic skull‐base surgery

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Specific targeting of metzincin family members with small-molecule inhibitors: Progress toward a multifarious challenge

Zn-metalloproteinases are an important class of hydrolytic enzymes that are characterized by the presence of a catalytic zinc(II) atom in their active center which is fundamental for proteolytic activity. Metzincins, a superfamily of Zn-metalloproteinases with many structural and functional commonalities among its members, are responsible for the fine tuning of key physiological functions in mammals and the deregulation of their activity is directly connected to numerous inflammatory and degenerative diseases such as arthritis or cancer. Development of small-molecule exogenous inhibitors of metzincins able to re-establish normal proteolytic activity in pathological conditions has been a field of intense research effort for many years but applications in the clinic were not always successful. One of the main reasons for this failure is the uncontrolled action of these inhibitors on target as well as anti-target metzincin family members. Current medicinal efforts have been shifted to the discovery of target-specific inhibitors that will help to improve our understanding of metzincins biological function and provide the basis for the development of safer pharmaceutical agents. This review focuses on the cases of certain medicinally important metzincins [matrix metalloproteinases (MMPs), a disintegrin and metalloproteinases (ADAMs), ADAMs with thrombospondin motifs (ADAMTSs), and procollagen C-proteinase (PCP)] and summarizes the latest advances on the discovery of inhibitors of these enzymes that display improved selectivity profiles. © 2008 Elsevier Ltd. All rights reserved

Shortcut to Fmoc-protected phosphinic pseudodipeptidic blocks

(Chemical Equation Presented) A three-component condensation reaction of Fmoc-carbamate, aldehydes, and alkylphosphinic acids provides a new, direct, and efficient method for synthesizing Fmoc-protected phosphinic pseudodipeptidic blocks, directly usable for solid-phase peptide synthesis. © 2005 American Chemical Society

Nω -linked arginine peptides

From Nα-trityl-L-arginine benzyl ester, Nω-glycyl-, Nω-L-valyl-, and Nω-L-arginyl-L-arginine have been prepared. These non-typical arginine peptides were transformed, especially in alkaline solution, into ornithine and the corresponding 2-iminoimidazolidin-4-one (glycocyamidine) derivatives. In this way the suggestion of Zervas and Bergmann that a non-typical Nω-L-arginyl-L-arginine is formed as an intermediate in the disproportionation of arginine methyl ester was confirmed. When arginine derivatives are used in peptide synthesis, the formation of non-typical arginine peptides can occur. This could lead to the final incorporation of ornithine instead of arginine into the peptide chain. © Royal Society of Chemistry

Synthetic active site-directed inhibitors of metzincins: Achievement and perspectives

The involvement of many zinc metalloproteinases belonging to the metzincin family with a variety of pathological states raises the possibility of therapeutic intervention using synthetic inhibitors with appropriate selectivity. Knowledge of the catalytic domain 3D-structures for various members of the metzincin family has been successfully exploited by chemists to develop potent synthetic inhibitors. However, despite intense efforts, very few highly selective inhibitors of metzincins have been discovered up to now. A survey of the literature suggests that the over-exploitation of the hydroxamate function as a zinc-binding group to develop inhibitors might be responsible for this situation. The use of alternative zinc-binding groups has led to more selective inhibitors, but the most encouraging results have been obtained for MMP-13 with compounds that do not incorporate zinc-binding groups in their structure. This new family of inhibitors exploits the presence of a deep S1′ cavity in the protease active site, a specific trait shared by many members of the metzincin family. However, to be successfully transposed to the metzincin members, this strategy will not only be able to exploit the structural detail of these S1′ cavities, but probably also subtle difference in their dynamics. © 2008 Elsevier Ltd. All rights reserved

Matrix metalloproteinase 11 (MMP-11; stromelysin-3) and synthetic inhibitors

Matrix metalloproteinase (MMP)-11, or Stromelysin 3, is a particular member of MMP family, a group of zinc-dependent endopeptidases involved in matrix degradation and tissue remodeling. Despite intense efforts since its first characterization 15 years ago, its role and target substrates in different diseases remain largely unknown. While mice with MMP-11 deficiency display no particular phenotype, analysis of different tumorigenesis models with these mice lead to the conclusion that MMP-11 promotes tumor development. In contrast with other MMPs, MMP-11 is unable to degrade any major extracellular matrix component and unlike most of other MMPs that are secreted as inactive proenzymes and activated extracellularly, MMP-11 is secreted under active form. MMP-11 may thus play a unique role in tissue remodeling processes, including those associated with tumor progression. Although MMP-11 and other MMPs have been considered as promising targets to combat cancer, a first series of clinical trials using broad-spectrum MMP inhibitors have not led to significant therapeutic benefits. These disappointing results highlight the need for better understanding of the exact role played by each MMP during the different stages of tumor progression. Among the different strategies to fill this gap, highly specific MMP inhibitors would be of great value. This review provides an update on the selectivity profile of phosphinic MMP-11 synthetic inhibitors developed and discusses the opportunities and limitations to identify inhibitors able to fully discriminate MMP-11 from the other MMPs. © 2006 Wiley Periodicals, Inc

Rapid access to the tricyclic spirotetronic core of abyssomicins

(Chemical Equation Presented) Abyssomicins, a novel class of polyketide antibiotics, are characterized by an unprecedented spirotetronic tricyclic subunit in their structure. In this letter, a short synthesis of a suitably functionalized tricyclic precursor of abyssomicins is reported. Key steps of the synthesis are (i) the highly stereoselective Al(III)-tethered Diels-Alder reaction and (ii) the tandem Dieckmann cyclization/TBS trapping of the C9 hydroxyl group followed by a regioselective intramolecular epoxide opening for the assembly of the target tricyclic structure. © 2005 American Chemical Society