Autonomic and peptidergic innervation of the human larynx

Asymmetry in the face and dentition is a naturally occurring phenomenon. In most cases facial asymmetry can only be detected by comparing homologous parts of the face. The etiology of asymmetry includes: a) Genetic or congenital malformations e.g. hemifacial microsomia and unilateral clefts of the lip and palate; b) Environmental factors, e.g. habits and trauma; c) Functional deviations, e.g. mandibular shifts as a result of tooth interferences. Dental asymmetries and a variety of functional deviations can be treated orthodontically. On the other hand, significant structural facial asymmetries are not easily amenable to orthodontic treatment. These problems may require orthopedic correction during the growth period and/or surgical management at a later point. Patient complaints and desires need to be addressed since they may vary from unrealistic expectations to a lack of concern even in the presence of large deviations. With mild dental, skeletal and soft tissue deviations the advisability of treatment should be carefully considered.     

The role of threonine in the P2 position of Bowman-Birk proteinase inhibitors: studies on P2 variation in cyclic peptides encompassing the reactive site loop

Previously, we have described a template-assisted combinatorial peptide library based on the anti-tryptic reactive site loop of a Bowman-Birk inhibitor (BBI). Sequences that displayed inhibitory activity re-directed towards chymotrypsin were found to have a consensus binding motif, with their most striking feature being that exclusively threonine was found at the P2 position. The present study investigates the reason for this surprising specificity by maintaining the binding motif but systematically varying the P2 residue. From analysis of 26 variants, it is found that the requirements for inhibitory activity at P2 are finely tuned, and in agreement with the library work, threonine at P2 provides optimal inhibition. In addition, peptides with threonine at P2 are significantly less susceptible to hydrolysis. Examination of all available BBI sequences shows that threonine is very highly conserved at P2, which implies that the functional requirement extends to the full-length BBI protein. Our results are consistent with a dual requirement for hydrophobic recognition within the S2 pocket and maintenance of an inhibitory conformation via hydrogen bonding within the reactive-site loop. As the isolated peptide loop reproduces the active region of full-length BBI, these results explain why threonine is well conserved at P2 in this class of inhibitor. Furthermore, they illustrate that proteinase inhibitor specificity can have characteristics that are not easily predicted from information on the substrate preferences of a proteinase.     

Idiopathic thrombocytopenic purpura in a liver transplant recipient with previous primary biliary cirrhosis

The loss of immunotolerance has been implicated in the pathogenesis of both primary biliary cirrhosis (PBC) and idiopathic, immune-mediated thrombocytopenic purpura (ITP). An association between these two autoimmune diseases has been well described. We describe a 41-year-old woman in whom ITP developed 457 days after liver transplantation for PBC while receiving immunosuppressive medications sufficient to maintain allograft function. Our case report, the first to describe post-transplant ITP in association with PBC, demonstrates the persistence of the underlying immune dysregulation of PBC after transplantation. The practice of decreasing the dosage of immunosuppressive medication to maintenance levels after transplantation may unmask the effects of this defect in immunotolerance.     

Effect of mechanical treatment on healing after third molar extraction

The aim of this study was to determine the effect of subgingival scaling and root planing on healing of the distal surface of second molars following extraction of third molars. Twenty-eight patients with contralateral erupted third molars and pocket depths greater than or equal to 3 mm on the distal surface of the second molars participated in this study. Measurements of supragingival bacterial plaque, bleeding on probing, pocket depth, and relative attachment level were performed at baseline and 2 months after treatment. Extraction of contralateral third molars was carried out simultaneously. The experimental site received thorough scaling and root planing of the distal surface of the second molar, while the control site received extraction alone. Experimental sites showed significant improvement in all clinical parameters assessed compared to the control sites. In conclusion, periodontal lesions on the distal of second molars can be significantly improved following scaling and root planing after extraction of third molars.     

Reactive and stimuli-responsive maleic anhydride containing macromers – multi-functional cross-linkers and building blocks for hydrogel fabrication

Macromers with functional groups that allow for chemical derivatization, polymerization reactions or impart specific physico-chemical properties are functional building blocks for polymeric systems used in different biomedical applications. With this motivation, a series of oligomeric macromers was synthesized by free radical polymerization of maleic anhydride (MA) with N-isopropylacrylamide (NiPAAm) and pentaerythritol diacrylate monostearate (PEDAS). This chemical design provides anhydride groups for effective reactivity of the macromers with amines and other nucleophiles, copolymerized NiPAAm for temperature responsiveness and lipophilic stearate domains for increased hydrogel stability. Macromers were synthesized with different MA co-monomer feeds and oligomeric molecules (Mn below 5000 Da) were obtained with MA contents between 7% and 27% as determined by titration. The fraction of chemically intact anhydrides was calculated to range from 75% to 80%. The ability of the macromers to cross-link di- or oligovalent amines as a function of MA content was investigated rheologically. It was also demonstrated that monovalent amines, e.g. aminofluorescein, could be grafted to the macromer chain utilizing only a fraction of the anhydride functionalities. The derivatized macromers could still participate in cross-linking reactions due to the remaining anhydrides. Temperature sensitivity was shown for aqueous solutions of macromers with fully dissociated anhydride groups. The solutions were additionally responsive to changes in calcium ion concentration and pH. Extracts from macromer cross-linked polyether hydrogels showed no toxicity on L929 fibroblasts.The macromers have perspective as biocompatible cross-linkers for hydrogel fabrication from various biomacromolecules with the opportunity to decorate the gels with monoamine molecules that alter the biological or physico-chemical properties.     

Different Enzymatic Processing of γ‐Phosphoramidate and γ‐Phosphoester‐Modified ATP Analogues

Monitoring the activity of ATP‐consuming enzymes provides the basis for elucidating their modes of action and regulation. Although a number of ATP analogues have been developed for this, their scope is restricted because of the limited acceptance by respective enzymes. In order to clarify which kind of phosphate‐modified ATP analogues are accepted by the α‐β‐phosphoanhydride‐cleaving ubiquitin‐activating enzyme 1 (UBA1) and the β‐γ‐phosphoanhydride‐cleaving focal adhesion kinase (FAK), we tested phosphoramidate‐ and phosphoester‐modified ATP analogues. UBA1 and FAK were able to convert phosphoramidate‐modified ATP analogues, even with a bulky modification like biotin. In contrast, a phosphoester‐modified analogue was poorly accepted. These results demonstrate that minor variations in the design of ATP analogues for monitoring ATP utilization have a significant impact on enzymatic acceptance.     

Small‐Molecule Inhibitors of the Tumor Suppressor Fhit

The tumor suppressor Fhit and its substrate diadenosine triphosphate (Ap₃A) are important factors in cancer development and progression. Fhit has Ap₃A hydrolase activity and cleaves Ap₃A into adenosine monophosphate (AMP) and adenosine diphosphate (ADP); this is believed to terminate Fhit‐mediated signaling. How the catalytic activity of Fhit is regulated and how the Fhit ? Ap₃A complex might exert its growth‐suppressive function remain to be discovered. Small‐molecule inhibitors of the enzymatic activity of Fhit would provide valuable tools for the elucidation of its tumor‐suppressive functions. Here we describe the development of a high‐throughput screen for the identification of such small‐molecule inhibitors of Fhit. Two clusters of inhibitors that decreased the activity of Fhit by at least 90 % were identified. Several derivatives were synthesized and exhibited in vitro IC₅₀ values in the nanomolar range.