Delta opioid receptor selective ligands; DPLPE-deltorphin chimeric peptide analogues†

Further efforts to correlate the topography of the bioactive structures of DPDPE and the deltorphins, two δ-opioid receptor active peptide families, are reported. A number of DPLPE-deltorphin chimeric peptides have been synthesized in which the C-terminal dipeptide δ-address of the deltorphins (-Val-GlyNH₂, -Nle-GlyNH₂) have been linked to the highly δ-opioid selective cyclic peptides DPDPE or DPLPE. These studies demonstrate that a major structural feature determining high potency of hybrid analogues is the chirality of the amino acid residue in position 5. The radioligand binding assays have revealed a decrease in potency (compared to DPDPE) at §-receptors when the C-terminal dipeptides were added to DPDPE. On the other hand, chimeric peptides of DPLPE with these same C-terminal dipeptides retained high δ-selectivity and affinity. Similar results were obtained using the mouse vas deferens (MVD) and guinea pig ileum (GPI) bioassays. The importance of the hydrophilicity of amino acids in positions 2 and 5 for δ-selectivity is consistent with the previous finding for DPLPE and DPDPE. On the other hand, the replacement of phenylalanine-4 with p-chlorophenylalanine-4 did not increase δ-selectivity as in DPDPE. These findings suggest that the δ-receptor interacts with hybridized enkephalins and deltorphins somewhat differently than with DPDPE.     

Oral florid papillomatosis in the course of lichen planus

The causal relationship between oral florid papillomatosis and lichen planus is discussed in the light of the literature and a case report.     

Lipid membrane permeability of modified c[D-Pen2, D-pen5]enkephalin peptides

Permeability coefficients of a series of analogues of a potent opioid peptide, c[D-Pen², D-Pen⁵]enkephalin, were measured in a model membrane system. The analogues included hydrophobic amino acid substitutions on position 3. Liposomes of a mixed composition consisting of zwitterionic lipids and cholesterol served as the model membranes. The obtained permeability coefficients range between 0.38 × 10^?12 and 2.9 × l0^?12 cm/s. These data were correlated with the hydrophobicity scale of Nozaki and Tanford (J. Biol. Chem. 246, 1971, 2211-2217) (correlation coefficient = 0.9933) and with determinations of lipid order perturbation by differential scanning calorimetry (correlation coefficient = -0.9779). The reasonably good correlation obtained within the family of analogues substituted on position 3 (Gly, Ala, Leu, Phe) indicates that changes in permeabilities are primarily related to increases in the partition coefficient of the peptide. However, Phe residue added on the N-terminal end of the peptide (position 0) does not appear to follow the observed trend, showing stronger lipid perturbation and lower permeability compared to the Phe³ analog. This observation demonstrates that each class of peptide modifications requires a new basis of permeability analysis and predictions. © Munksgaard 1996.     

Reduced-dose rocuronium for day-case tonsillectomy in children where volatile anaesthetics are not used: operating room time saving

Objectives: Mivacurium, rocuronium, and vecuronium are neuromuscular blocking agents (NMB) commonly used in pediatric day‐case anesthesia. Mivacurium is the most appropriate NMB for short surgical procedures where NMB drugs were required but is not available in all countries. Aim: We evaluated the operating room time minimization after reduced‐dose rocuronium (0.45 mg·kg^?1) during elective day‐case tonsillectomy in children. Methods/Materials: One hundred and five children (6–9 years, ASA I/II status) scheduled for day‐case tonsillectomy were included in prospective, double blind clinical study. Children were randomly divided in three equal groups. All children were premedicated (midazolam 0.25 mg·kg^?1 orally, EMLA). Anesthesia was induced (2.5 mg·kg^?1) and maintained (0.1 mg·kg^?1·min^?2) by propofol and alfentanil (0.0015 mg·kg^?1·min^?1) and supplemented by inhalation mixture of 50% of O2/Air. Neuromuscular block was achieved by vecuronium (0.1 mg·kg^?1) (V) or rocuronium in standard (0.6 mg·kg^?1) (R) or reduced dose (0.45 mg·kg^?1) (LD). Neuromuscular transmission was monitored by acceleromyography. Time analysis of NMB drugs action was performed. Results: Time difference from the end of tonsillectomy to T90 neuromuscular block recovery was significantly shorter in LD Group (7.3 ± 0.41 min), (V = 15.9 ± 1.06, R = 16.0 ± 1.7 min) (P = 0.0011). The onset time of neuromuscular block was prolonged in LD Group (LD=3.1 ± 0.4, R = 1.3 ± 0.4, V = 2.2 ± 0.2 min) (P = 0.0039) without changing the intubating conditions. The maximum operation room time saving per each tonsillectomy was 37% in LD Group (Group V 21%, Group R 17%) (P = 0.0001). Low incidence of postoperative nausea and vomiting (PONV) 3–6% (0.4577) and good visual analog scale (VAS) score (≤2) (0.5969) were found in all study groups 12 h after surgery. Conclusions: Reduced‐dose rocuronium in addition with propofol and alfentanil in children where volatile anesthetics are not used effectively saves the operating room time during short elective surgical procedures, avoids delays in patient recovery, allows high level of acceptable intubating conditions, and improves the optimal surgical work. Low incidences of PONV as VAS score may achieved successfully.     

Immunosuppressive analogues of hexapeptide Tyr-Val-Pro-Leu-Phe-Pro,an immune system stimulant

It was found that substitution of Val² and/or Leu⁴ residue in a hexapeptide Tyr-Val-Pro-Leu-Phe-Pro (I) transforms this peptide immunostimulant into analogues possessing the immunosuppressor activity – Tyr-Gly-Pro-Leu-Phe-Pro (II), Tyr-Val-Pro-Gly-Phe-Pro (III), and Tyr-Gly-Pro-Gly-Phe-Pro (IV). Biological effects of peptides I-IV were studied using PFC (plaque forming cell) test, GvH (graft vs host) reaction in mice, and ARFC (autologous rosette forming cell) test. The strongest immunosuppressor activity was observed for III – in this case the immunosuppressor effect was observed even in PFC test in vitro in which II and IV showed no such activity. These results suggest that simultaneous presence of both Val² and Leu⁴ residues is necessary for the generation of immunostimulation. The CD study of I-IV in methanol solution suggests that the conformational preferences of II-IV change towards stabilization of the β-turn structure, whereas in the case of I the γ-turn on Leu⁴ and cis orientation of the Pro³ carbonyl (distorted β-turn of type I) was found (1) as the preferred conformation. Competition in biological effects observed for I and III in PFC in vitro test suggests that these analogues may interact with the same cellular receptor. Drastic changes in the activity which accompany changes in the sequence are discussed in the terms of our stereochemical hypothesis (1).     

Antitumor effect of ascorbic acid, lysine, proline, arginine, and green tea extract on bladder cancer cell line T-24

AIMS: Bladder cancer, the fourth highest incident cancer in men and tenth in women, is associated with a high rate of recurrence, even when treated in situ, and prognosis is poor once the cancer metastasizes to distant sites. Based on anticancer properties, we investigated the effect of a mixture of lysine, proline, arginine, ascorbic acid, and green tea extract on human bladder cancer cells T-24 by measuring: proliferation, matrix metalloproteinase (MMP) expression, and cancer cell invasive potential. METHODS: Human bladder cancer cells T-24 (ATCC) were grown in McCoy medium supplemented with 10% fetal bovine serum, penicillin (100 U/mL) and streptomycin (100 mg/mL) in 24-well tissue culture plates. At near confluence, the cells were treated with the nutrient mixture dissolved in media and tested at 0, 10, 50, 100, 500, and 1000 microg/mL in triplicate at each dose. Cells were also treated with PMA 200 ng/mL to study enhanced MMP-9 activity. Cell proliferation was evaluated by MTT assay, MMP activity by gelatinase zymography, and invasion through Matrigel. RESULTS: Nutrient mixture inhibited the T-24 cell secretion of MMP-2 and -9, with virtual total inhibition of MMP-2 at 500 microg/mL and MMP-9 at 100 microg/mL. The nutrient mixture significantly reduced the invasion of human bladder cancer cells T-24 through Matrigel in a dose-dependent fashion, with 95% inhibition at 500 microg/mL and 100% at 1000 microg/mL nutrient mixture (P < 0.001). CONCLUSION: Our results suggest that our nutrient mixture is an excellent candidate for therapeutic use in the treatment of bladder cancer, by inhibiting critical steps in cancer development and spread, such as MMP secretion and invasion.     

Triple-Site Versus Standard Cardiac Resynchronization Therapy Study (TRUST CRT): Clinical Rationale, Design, and Implementation

Background: Cardiac resynchronization therapy (CRT) reduces morbidity and mortality in patients with heart failure (HF), lowered LV ejection fraction, and wide QRS. However, many patients (≤40%) do not respond to this form of pacing. TRUST CRT is a prospective, single-center, randomized, single-blind, parallel, and controlled study that has been designed to treat patients with moderate to severe HF (NYHA III-IV), QRS ≥120 ms, sinus rhythm, LV dysfunction (EF ≤ 35%), and signs of mechanical dyssynchrony.
Objective: The primary objective will evaluate the 6-month's combined endpoint of alive status, freedom from hospitalization for HF or heart transplantation, relative ≥10% increase in LV ejection fraction, ≥10% in peak oxygen consumption, and ≥10% in 6-minute walking distance.
Methods: Patients with HF receiving optimal pharmacotherapy, with LV dysfunction, mechanical dyssynchrony, wide QRS and sinus rhythm will be randomized in a 1: 1 fashion to standard or triple-site CRT-D. Patients will be followed for 1 week, 1, 3, and 6 months during a blind phase, then every 6 months until study completion. One hundred patients will be enrolled by the study center.
Conclusions: TRUST CRT is a randomized, clinical trial in CRT candidates to evaluate the effectiveness of triple-site pacing versus standard resynchronization in patients with HF.     

Implantation Feasibility,Procedure‐Related Adverse Events and Lead Performance During 1‐Year Follow‐Up in Patients Undergoing Triple‐Site Cardiac Resynchronization Therapy: A Substudy of TRUST CRT Randomized Trial

Feasibility and Safety of Triple‐Site CRT . Introduction: This substudy was to assess implantation feasibility and long‐term safety of triple‐site resynchronization therapy (CRT) in a series of consecutive patients included in a randomized trial. Methods and results: One hundred consecutive patients enrolled into Triple‐Site Versus Standard Cardiac Resynchronization Therapy Randomized Trial were analyzed. Eligibility criteria included NYHA class III‐IV, sinus rhythm, QRS ≥ 120 milliseconds, left ventricular ejection fraction ≤35%, and significant mechanical dyssynchrony. Patients were randomized in a 1:1 ratio to conventional or triple‐site CRT with defibrillator–cardioverter. After 12 months of resynchronization 30% of patients with conventional resynchronization and 12.5% with triple‐site CRT were in NYHA functional class III or IV (P < 0.05). Implantation of triple‐site systems was significantly longer (median 125 minutes vs 96 minutes; P < 0.001), with higher fluoroscopic exposure, especially in patients with very enlarged left ventricle or pulmonary hypertension. Implantation success‐rate was similar in the triple‐site and conventional group (94% vs 98%; P = NS); however, additional techniques had to be used in a greater proportion of the triple‐site patients (33.3% vs 16%; P < 0.05). Long‐term lead performance tests revealed significantly higher pacing threshold and lower impedance in the triple‐site group. The 1‐year incidence of serious, CRT‐related adverse events was similar in triple‐site and conventional group (20.8% vs 30%; P = NS). Conclusions: Triple‐site CRT is associated with more pronounced functional improvement than standard resynchronization. This form of pacing is equally safe and feasible as the conventional CRT. However, triple‐site procedure is more time‐consuming, associated with higher radiation exposure and the need to use additional techniques. Triple‐site resynchronization is associated with less favorable electrical lead characteristics. (J Cardiovasc Electrophysiol, Vol. 23, pp. 1228–1236, November 2012)     

Synthesis and biological properties of β-MePhe3 analogues of deltorphin I and dermenkephalin: influence of biased X1 of Phe3 residues on peptide recognition for δ-opioid receptors

Using the method of conformational constraint, we have designed and synthesized analogues of deltorphin I and dermenkephalin containing each of the four stereoisomers (2S, 3S: 2S, 3R; 2R, 3S; 2R, 3R) of the unusual amino acid ß-methylphenylalanine in position three. The potency and selectivity of these analogues were evaluated by radioreceptor binding assays in the rat brain using [³H]CTOP (δ-ligand) and [³H][p-CβPhe⁴]DPDPE (β-ligand), and by bioassay using the mouse vas deferens (β-receptor assay) and guinea pig ileum (β-receptor assay) assays. The substitution of a ß-MePhe for Phe³ in deltorphin I and dermenkephalin has a large and variable effect on the bioactivities of the synthesized analogues. The synthesized analogues are somewhat less potent than the native peptides. Both [(2S, 3R)-ß-MePhe³]deltorphin and [(2S, 3R)-ß-MePhe³]dermenkephalin are more selective, however, and interact essentially specifically with the receptor in the binding assays and bioassays. The bioassay data in vitro of the synthesized analogues of deltorphin I and dermenkephalin follow the same general trends as the receptor binding data. These results demonstrate that topographical modifications of the side-chain conformation of critical structural moieties in a ligand can significantly modulate both the potency and receptor selectivity for ligands that have multiple sites of biological activity, and they illustrate that this approach has general application to peptide and peptidomimetic ligand design.     

Oral health-related quality of life of children with oligodontia

Objectives.  To assess the functional and psychosocial impact of oligodontia in children aged 11–14 years.
Methods.  Children aged 11–14 years with oligodontia were recruited from orthodontic clinics when they presented for orthodontic evaluation. All completed a copy of the Child Perceptions Questionnaire for 11- to 14-year olds, a measure of the functional and psychosocial impact of oral disorders. Information on the number and pattern of missing teeth for each child were obtained from charts and radiographs.
Results.  Thirty-six children were included in the study. The number of missing teeth ranged from one to 14 (mean = 6.8). Just over three-quarters of the subjects reported experiencing one or more functional and psychosocial impacts 'Often' or 'Everyday/almost everyday'. Correlations between scale and sub-scale scores and the number of missing teeth were weak and nonsignificant.
Conclusions.  Children with oligodontia experience substantial functional and psychosocial impacts from the condition. When compared with other clinical groups, children with oligodontia appear to have worse oral health-related quality of life than children with dental decay and malocclusion, but better oral health-related quality of life than children with oro-facial conditions.