Discovery of ONO-8590580: A novel, potent and selective GABAA α5 negative allosteric modulator for the treatment of cognitive disorders.

The identification and SAR development of a series of negative allosteric modulators of the GABAA α5 receptor is described. This novel series of compounds was optimised to provide analogues with high GABAA α5 binding affinity, high α5 negative allosteric modulatory activity, good functional subtype selectivity and low microsomal turnover, culminating in identification of ONO-8590580.

Spiropiperidines as high-affinity, selective sigma ligands.

A variety of achiral conformationally restricted spirocyclic piperidines have been prepared in an attempt to investigate the functional role of the central sigma recognition site. All the compounds possessed a lipophilic N-substituent incorporating either a tetralin, indan, or benzocycloheptane skeleton. Their in vitro affinity at the sigma site was assessed in radioligand displacement experiments with guinea pig cerebellum homogenates using the sigma-specific radioligand [3H]-N,N'-di-o-tolylguanidine ([3H]-DTG, [3H]-6). A study of the structure-activity relationships identified the N-butyl and N-dimethylallyl substituents as the optimum groups for high affinity and selectivity at the sigma site (e.g., 3,4-dihydro-1'-(3-methylbut-2-enyl)spiro[1H-indene-1,4'-piperidine ] (48), pIC50 = 8.9 vs [3H]-6 and greater than 10,000-fold selective over the dopamine D2 receptor). Such compounds are amongst the highest affinity sigma ligands reported to date, with excellent selectivity over the dopamine D2 receptor, and may serve as a useful tool for exploring the physiological role of the sigma site.

Synthesis and serotonergic activity of 5-(oxadiazolyl)tryptamines: potent agonists for 5-HT1D receptors.

The synthesis and 5-HT1D receptor activity of a novel series of 5-(oxadiazolyl)tryptamines is described. Modifications of the oxadiazole 3-substituent, length of the linking chain (n), and the amine substituents are explored and reveal a large binding pocket in the 5-HT1D receptor domain. Oxadiazole substituents such as benzyl are accommodated without loss of agonist potency or efficacy. The incorporation of polar functionality on a phenyl or benzyl spacer group results in a 10-fold increase in affinity and functional potency. Optimal 5-HT1D activity is observed when the heterocycle is conjugated with the indole and the benzyl sulfonamides 20t and 20u represent some of the most potent 5-HT1D agonists known. Replacement of O for S in the heterocycle leads to a further increase in potency. Deletion of oxadiazole N-2 does not reduce activity, suggesting the requirement for only one H-bond acceptor in this location. The selectivity of these compounds for 5-HT1D receptors over other serotonergic receptors is discussed. Sulfonamide 20t shows > or = 1000-fold selectivity for 5-HT1D over 5-HT2, 5-HT1C, and 5-HT3 receptors and 10-fold selectivity with respect to 5-HT1A receptors. The functional activity of this series of compounds is studied and demonstrates high 5-HT1D receptor potency and efficacy comparable to that of 5-HT.

3-(Piperazinylpropyl)indoles: selective, orally bioavailable h5-HT1D receptor agonists as potential antimigraine agents.

Clinically effective antimigraine drugs such as Sumatriptan have similar affinity at h5-HT1D and h5-HT1B receptors. In the search for a h5-HT1D-selective agonist as an antimigraine agent, a novel series of 3-(propylpiperazinyl)indoles have been synthesized and evaluated at h5-HT1D and h5-HT1B receptors. This class of compounds has provided subnanomolar, fully efficacious h5-HT1D agonists with up to 200-fold selectivity for the h5-HT1D receptor over the h5-HT1B receptor. Unlike other h5-HT1D-selective series, several propylpiperazines demonstrate good oral bioavailability. The optimum compound was 1-(3-[5-(1,2, 4-triazol-4-yl)-1H-indol-3-yl]propyl)-4-(2-(3-fluorophenyl)ethyl)p ipe razine (7f) which has excellent selectivity for h5-HT1D receptors over other 5-HT receptor subtypes and good oral bioavailability in three species. Compound 7f has been selected for further investigation as a potential development candidate in the treatment of migraine.

N-heteroaryl-2-phenyl-3-(benzyloxy)piperidines: a novel class of potent orally active human NK1 antagonists.

The preparation of a series of N-heteroarylpiperidine ether-based human NK1 antagonists is described. Two of the compounds 3-[-(2S,3S)-3-(((3,5-bis(trifluoromethyl)phenyl)methyl)oxy)- 2-phenylpiperidino}methyl]-1,2,4-triazole (11) and 5-[¿(2S,3S)-3-(((3,5-bis(trifluoromethyl)-phenyl)methyl)oxy)-2- phenylpiperidino}methyl]-3-oxo-1,2,4-triazolone (12)), in particular, are orally bioavailable and exhibited significant improvements in potency, both in vitro and in vivo, over the lead (carboxamidomethyl)piperidine ether 1. Rat liver microsome studies on a selected number of compounds from this series show the triazolone heterocycle to be considerably more stable than the others. Furthermore, both 11 and 12 have been profiled in a number of assays that may be predictive of the clinical utility of substance P antagonists.

Minimizing oral complications of cancer treatment.

Aggressive cancer therapy places patients at greater risk for oral complications and treatment-related consequences. Unfortunately, prevention and/or treatment of such oral sequelae have become often overlooked priorities of the treatment team. We describe a philosophy of management of the cancer patient that specifically emphasizes the prevention and treatment of oral complications associated with cancer therapy. These concepts and principles are based on treatment protocols and ongoing clinical practices at The University of Texas M. D. Anderson Cancer Center in Houston, Texas.

Prosthetic rehabilitation of patients with advanced nonmelanoma skin cancer.

Attention to detail at all stages of treatment can ensure a successful prosthetic rehabilitation. This detail must be considered a priority at presurgery, surgery, and at every stage in fabricating the prosthesis. Teamwork between the surgeon and maxillofacial prosthodontist will ensure an optimal surgical preparation and definitive prosthesis. Evidence of interaction among team members most certainly can be encouraging to the patient. It is important that during the prosthetic phase of treatment, attention be made in terms of tissue assessment, impression making, sculpting, mold fabrication, familiarity with materials, appreciation of color, delivery of instructions, and patient education, which will ensure a satisfactory outcome. With the desire, determination, and encouragement from the restorative team to make the most of this artificial replacement, a patient can have a higher quality of life and a more normalized lifestyle.

Rehabilitation of a midface defect with reconstructive surgery and facial prosthetics: a case report.

This paper reports a case in which reconstruction of a midface defect was accomplished by using microvascular surgery with free tissue transfer of the fibula for a 55-year-old man with squamous cell carcinoma in the nasal vestibule and nasal wall. This technique was developed and first used to reconstruct mandibular defects. Using a surgical template during the midface reconstruction can help the surgeon place the graft in a position that will complement the definitive facial prosthesis, as illustrated in this report.

Oral complications associated with aspergillosis in patients with a hematologic malignancy. Presentation and treatment.

Opportunistic mycotic infections, such as aspergillosis, can produce morbid consequences with or without aggressive therapy in an immunocompromised patient. Treatment including amphotericin B and resection of the infected tissue must be considered early in the overall management of the patient. We describe two patients with acute myelogenous leukemia who underwent intense cytoreductive therapy with bone marrow transplantation and an associated fungal infection treated with an investigational form of amphotericin B.

Prosthodontic and surgical considerations for pediatric patients requiring maxillectomy.

The quality of treatment and rehabilitation for the head and neck cancer patient, especially the pediatric patient, has progressed markedly over the years due to the cooperation of specialists involved in the total care of the patient. Defects of the oral cavity caused by trauma or removal of malignant or benign tissue require special treatment considerations with the pediatric patient. Aside from radiation and chemotherapy, other forms of adjuvant therapy, such as physical therapy, and patient and family counseling, are needed for proper rehabilitation. In addition, oral hygiene is essential in the overall rehabilitative process. Pediatric dental, orthodontic, prosthodontic, and oral and maxillofacial surgery specialties become integrated in treating the pediatric patient. The concentrated multidisciplinary treatment reduces post-treatment morbidity by shortening recovery and immediate rehabilitation time and by providing long-term care during the critical growth period.

Postoperative care of the maxillectomy patient.

Guidelines for preoperative patient information and immediate postoperative care of the maxillectomy patient are discussed. Physical therapy, oral hygiene procedures, and current materials for surgical obturation and their uses are reviewed. Effective treatments for infections that arise in the surgical defect are highlighted.

Aldehyde oxidase and its contribution to the metabolism of a structurally novel, functionally selective GABAA alpha5-subtype inverse agonist.

(3-Tert-butyl-7-(5-methylisoxazol-3-yl)-2-(1-methyl-1H-1,2,4-triazol-5-ylmethoxy)pyrazolo[1,5-d] [1,2,4]triazine was recently identified as a functionally selective, inverse agonist at the benzodiazepine site of GABA(A) alpha5-containing receptors, which enhances performance in animal models of cognition. The routes of metabolism of this compound in rat, dog, rhesus monkey and human in vitro systems, and in vivo in rat, dog and rhesus monkey have been characterized. The current study demonstrates that both a cytosolic oxidative reaction and cytochrome P450 play important roles in the metabolism of the compound. Chemical inhibition studies showed the oxidation in human cytosol to be catalysed predominantly by aldehyde oxidase rather than the related enzyme, xanthine oxidase. The aldehyde oxidase-mediated metabolites were present in vitro and in vivo in both rat and rhesus monkey, and also in vitro in man. They were absent both in vitro and in vivo in dog.

Patient appointments during interim obturation: is it cost-effective?

PURPOSE: The purpose of this study was to quantify the number of patient appointments needed during the interim obturator service period in the Department of Dental Oncology at MD Anderson Cancer Center (Houston, TX). MATERIALS AND METHODS: A retrospective study evaluating 100 patient records of patients who underwent maxillectomies between 1989 and 1993. RESULTS: Of the 100 patients analyzed, 42 patients had a definitive prosthesis fabricated within 90 days after surgery. On average, 12 appointments (range, 6-24 appointments) were recorded for each patient during this 90-day global interim obturator period. CONCLUSIONS: The 12 appointments reflect a considerable amount of clinical and laboratory effort and reinforces the national concern of proper reimbursement.

Technique for magnet replacement in silicone facial prostheses.

Magnets are often used in silicone facial prostheses for retention. However, these magnets may need to be replaced or repositioned as a result of loss, wear, or poor initial placement. Replacement can be easily accomplished by use of a nylon mesh material and a simple laboratory technique.

Color stability of facial prostheses.

The limited service of facial prostheses is the result of degradation of the elastomer and color instability. Deterioration may be caused by many factors, which include environmental exposure and changes in humidity. This investigation assessed the efficacy of an additive, intrinsic, broad-spectrum ultraviolet light absorber on the color stability of a pigmented facial elastomer. Samples were weathered artificially and outdoors at exposure levels of radiant energy of 150 to 450 kJ/m2. The samples changed color slightly but perceptibly. Artificial aging caused a greater change than outdoor aging. The ultraviolet light absorber UV-5411 did not protect the samples from color changes.

A hybrid-mold technique for fabricating facial prostheses.

A hybrid-mold technique is described for fabricating facial prostheses with delicate contours and/or undercuts that require additional support. This quick and simple technique combines several common laboratory materials and protects select areas of the stone mold during prosthesis fabrication. This technique also extends the mold's years of service and the number of prostheses that can be fabricated from the mold.