Gorlin-Goltz Syndrome - A Rare Case Entity in Young Child.

Gorlin-Goltz syndrome (GGS) is an infrequent multisystemic disease with an autosomal dominant trait, which depicted presence of numerous basal cell carcinoma in conjunction with multiorgan abnormalities. This syndrome may be diagnosed early by a dentist by routine radiographic exams in the first decade of life, since the keratocystic odontogenic tumour are usually one of the first manifestations of the syndrome. This article includes a case report of the GGS with regard to its history, incidence, etiology, features, investigations, diagnostic criteria, keratocystic odontogenic tumour and treatment modalities.

Catalyzing Bond-Dissociation in Graphene via Alkali-Iodide Molecules.

Atomic design of a 2D-material such as graphene can be substantially influenced by etching, deliberately induced in a transmission electron microscope. It is achieved primarily by overcoming the threshold energy for defect formation by controlling the kinetic energy and current density of the fast electrons. Recent studies have demonstrated that the presence of certain species of atoms can catalyze atomic bond dissociation processes under the electron beam by reducing their threshold energy. Most of the reported catalytic atom species are single atoms, which have strong interaction with single-layer graphene (SLG). Yet, no such behavior has been reported for molecular species. This work shows by experimentally comparing the interaction of alkali and halide species separately and conjointly with SLG, that in the presence of electron irradiation, etching of SLG is drastically enhanced by the simultaneous presence of alkali and iodine atoms. Density functional theory and first principles molecular dynamics calculations reveal that due to charge-transfer phenomena the CC bonds weaken close to the alkali-iodide species, which increases the carbon displacement cross-section. This study ascribes pronounced etching activity observed in SLG to the catalytic behavior of the alkali-iodide species in the presence of electron irradiation.

Oral Malignant Melanoma: A Case Report.

Melanoma is a malignant neoplasm of the epidermal melanocytes. Awareness and early recognition of pigmented lesion inside oral cavity helps in initial diagnosis and further investigation and treatment. Oral malignant melanoma is a rare aggressive neoplasm commonly seen among middle age. The diagnosis of melanoma initiates from the pre-existing pigmented lesions. The poor prognosis of oral melanomas requires that pigmented lesions of undetermined origin be routinely biopsied. A case of malignant melanoma of hard palate with its clinical, radiological and histopathological presentation along with brief review is presented. Prognosis of these lesion is poor with survival rate of 5 years.

Oral manifestation and its management in postmenopausal women: an integrated review.

Postmenopause is a phase of life which leads physical and emotional instability from multiple health related issues. Oral health in this stage of life is also compromised. Oral health has an impact on general wellbeing of the individual as oral cavity is commonly act as a mirror to general health. Menopause is phase in a woman's life when menstrual cycles cease by reduced secretion of the ovarian hormones, such as estrogen and progesterone. This review article has emphasized on the diverse oral presentations of peri- and postmenopausal phase of women's life. Practicing dental surgeons and general physician should be aware of the possible association of postmenopause and its various oral signs and symptoms in this midlife phase of women. It also focuses on its symptomatic management of various oral health issues. This article explains diverse oral conditions in detailed and their management. Stress causing anxiety and depression among this midlife phase of women can lead to alteration in immunity which can again lead to various oral conditions, like lichen planus, apthous ulcer that can cause burning sensation in oral mucosa and alter the food habit. By dealing with all this diverse condition, practicing oral physician can help to reduce and manage oral manifestation of postmenopausal phase of life.

Mechanism of Olefin Metathesis with Neutral and Cationic Molybdenum Imido Alkylidene N-Heterocyclic Carbene Complexes.

A series of neutral molybdenum imido alkylidene N-heterocyclic carbene (NHC) bistriflate and monotriflate monoalkoxide complexes as well as cationic molybdenum imido alkylidene triflate complexes have been subjected to NMR spectroscopic, X-ray crystallographic, and reaction kinetic measurements in order to gain a comprehensive understanding about the underlying mechanism in olefin metathesis of this new type of catalysts. On the basis of experimental evidence and on DFT calculations (BP86/def2-TZVP/D3/cosmo) for the entire mechanism, olefinic substrates coordinate trans to the NHC of neutral 16-electron complexes via an associative mechanism, followed by dissociation of an anionic ligand (e.g., triflate) and formation of an intermediary molybdacyclobutane trans to the NHC. Formation of a cationic complex is crucial in order to become olefin metathesis active. Variations in the NHC, the imido, the alkoxide, and the noncoordinating anion revealed their influence on reactivity. The reaction of neutral 16-electron complexes with 2-methoxystyrene is faster for catalysts bearing one triflate and one fluorinated alkoxide than for catalysts bearing two triflate ligands. This is also reflected by the Gibbs free energy values for the transition states, Δ G‡303, which are significantly lower for catalysts bearing only one triflate than for the corresponding bistriflate complexes. Reaction of a solvent-stabilized cationic molybdenum imido alkylidene N-heterocyclic carbene (NHC) monotriflate complex with 2-methoxystyrene proceeded via an associative mechanism too. Reaction rates of both solvent-free and solvent-stabilized cationic Mo imido alkylidene NHC catalysts with 2-methoxystyrene are controlled by the cross-metathesis step but not by adduct formation.

Promoting Terminal Olefin Metathesis with a Supported Cationic Molybdenum Imido Alkylidene N-Heterocyclic Carbene Catalyst.

Silica-supported cationic Mo-imido alkylidene N-heterocyclic carbene catalysts, prepared by surface organometallic chemistry, display contrasting olefin metathesis activity for terminal and internal olefins. The high metathesis activity towards terminal alkenes is attributed to the strong σ-donating property of the NHC ancillary ligand, which disfavors the formation of the parent square-planar metallacyclobutane, an off-cycle reaction intermediate resulting from the reaction with ethylene, one of the metathesis products. This tailored ligand environment also allowed the first trigonal bipyramidal (TBP) metallacyclobutane reaction intermediate for supported Mo metathesis catalysts to be identified.

Neutral and Cationic Molybdenum Imido Alkylidene N-Heterocyclic Carbene Complexes: Reactivity in Selected Olefin Metathesis Reactions and Immobilization on Silica.

The synthesis and single-crystal X-ray structures of the novel molybdenum imido alkylidene N-heterocyclic carbene complexes [Mo(N-2,6-Me2C6H3)(IMesH2)(CHCMe2Ph)(OTf)2] (3), [Mo(N-2,6-Me2C6H3)(IMes)(CHCMe2Ph)(OTf)2] (4), [Mo(N-2,6-Me2C6H3)(IMesH2)(CHCMe2Ph)(OTf){OCH(CF3)2}] (5), [Mo(N-2,6-Me2C6H3)(CH3CN)(IMesH2)(CHCMe2Ph)(OTf)](+)BArF(-) (6), [Mo(N-2,6-Cl2C6H3)(IMesH2)(CHCMe3)(OTf)2] (7) and [Mo(N-2,6-Cl2C6H3)(IMes)(CHCMe3)(OTf)2] (8) are reported (IMesH2=1,3-dimesitylimidazolidin-2-ylidene, IMes=1,3-dimesitylimidazolin-2-ylidene, BArF(-)=tetrakis-[3,5-bis(trifluoromethyl)phenyl] borate, OTf=CF3SO3(-)). Also, silica-immobilized versions I1 and I2 were prepared. Catalysts 3-8, I1 and I2 were used in homo-, cross-, and ring-closing metathesis (RCM) reactions and in the cyclopolymerization of α,ω-diynes. In the RCM of α,ω-dienes, in the homometathesis of 1-alkenes, and in the ethenolysis of cyclooctene, turnover numbers (TONs) up to 100,000, 210,000 and 30,000, respectively, were achieved. With I1 and I2, virtually Mo-free products were obtained (<3 ppm Mo). With 1,6-hepta- and 1,7-octadiynes, catalysts 3, 4, and 5 allowed for the regioselective cyclopolymerization of 4,4-bis(ethoxycarbonyl)-1,6-heptadiyne, 4,4-bis(hydroxymethyl)-1,6-heptadiyne, 4,4-bis[(3,5-diethoxybenzoyloxy)methyl]-1,6-heptadiyne, 4,4,5,5-tetrakis(ethoxycarbonyl)-1,7-octadiyne, and 1,6-heptadiyne-4-carboxylic acid, underlining the high functional-group tolerance of these novel Group 6 metal alkylidenes.

A Phase IB multicentre dose-determination study of BHQ880 in combination with anti-myeloma therapy and zoledronic acid in patients with relapsed or refractory multiple myeloma and prior skeletal-related events.

Dickkopf-1 (DKK1), expressed by myeloma cells, suppresses osteoblast function and plays a key role in bone disease in multiple myeloma. BHQ880, a human neutralizing IgG1 anti-DKK1 monoclonal antibody, is being investigated for its impact on multiple myeloma-related bone disease and as an agent with potential anti-myeloma activity. The primary objectives of this Phase IB study were to determine the maximum tolerated dose (MTD) of BHQ880 and to characterize the dose-limiting toxicity (DLT) of escalating doses in combination with anti-myeloma therapy and zoledronic acid. Twenty-eight patients were enrolled and received BHQ880 at doses of 3-40 mg/kg. No DLTs were reported, therefore, the MTD was not determined. The recommended Phase II dose was declared as 10 mg/kg, based mainly on saturation data. There was a general trend towards increased bone mineral density (BMD) observed over time; specific increases in spine BMD from Cycle 12 onwards irrespective of new skeletal-related events on study were observed, and increases in bone strength at the spine and hip were also demonstrated in some patients. BHQ880 in combination with zoledronic acid and anti-myeloma therapy was well tolerated and demonstrated potential clinical activity in patients with relapsed or refractory multiple myeloma.

N-heterocyclic carbene, high oxidation state molybdenum alkylidene complexes: functional-group-tolerant cationic metathesis catalysts.

We synthesized the first N-heterocyclic carbene (NHC) complexes of Schrock's molybdenum imido alkylidene bis(triflate) complexes. Unlike existing bis(triflate) complexes, the novel 16-electron complexes represent metathesis active, functional-group-tolerant catalysts. Single-crystal X-ray structures of two representatives of this novel class of Schrock catalysts are presented and reactivity is discussed in view of their structural peculiarities. In the presence of monomer (substrate), these catalysts form cationic species and can be employed in ring-closing metathesis (RCM), ring-opening metathesis polymerization (ROMP), as well as in the cyclopolymerization of α,ω-diynes. Monomers containing functional groups, which are not tolerated by the existing variations of Schrock's catalyst, e.g., sec-amine, hydroxy, and carboxylic acid moieties, can be used. These catalysts therefore hold great promise in both organic and polymer chemistry, where they allow for the use of protic monomers.

Molecular sensitised probe for amino acid recognition within peptide sequences.

The combination of low-temperature scanning tunnelling microscopy with a mass-selective electro-spray ion-beam deposition established the investigation of large biomolecules at nanometer and sub-nanometer scale. Due to complex architecture and conformational freedom, however, the chemical identification of building blocks of these biopolymers often relies on the presence of markers, extensive simulations, or is not possible at all. Here, we present a molecular probe-sensitisation approach addressing the identification of a specific amino acid within different peptides. A selective intermolecular interaction between the sensitiser attached at the tip-apex and the target amino acid on the surface induces an enhanced tunnelling conductance of one specific spectral feature, which can be mapped in spectroscopic imaging. Density functional theory calculations suggest a mechanism that relies on conformational changes of the sensitiser that are accompanied by local charge redistributions in the tunnelling junction, which, in turn, lower the tunnelling barrier at that specific part of the peptide.

Imaging nigral pathology and clinical progression in Parkinson's disease.

The pattern of dopamine cell loss in Parkinson's disease (PD) is known to be prominent in the ventrolateral and caudal substantia nigra (SN), but less severe in the dorsal and rostral region. Both diffusion tensor imaging (DTI) and R2* relaxometry of the SN have been reported as potential markers for PD, but their relative ability to mark disease progression and differences in pathophysiological bases remains unclear. High-resolution T2-weighted, R2*, and DTI were obtained from 28 controls and 40 PD subjects [15 early stage [disease duration ≤1 year], 14 mid stage [duration 2-5 years], and 11 late stage [duration >5 years]). Fractional anisotropy and R2* values in both rostral and caudal SN were obtained for all subjects, and clinical measures (e.g., disease duration, levodopa-equivalent daily dosage, and "off"-drug UPDRS motor score) were obtained for Parkinson's subjects. There was no correlation between fractional anisotropy and clinical measures, whereas R2* was strongly associated with disease progression. Compared to controls, fractional anisotropy in caudal SN was significantly decreased in PD patients of all stages, whereas in rostral SN, it was decreased significantly only in the late-stage group. R2* in both SN regions was significantly increased in the mid- and late-stage, but not early-stage, of PD subjects. These findings suggest that fractional anisotropy changes may mark early pathological changes in caudal SN, whereas the changes in R2* may more closely track PD's clinical progression after symptom onset.

Palladium electrodes for molecular tunnel junctions.

Gold has been the metal of choice for research on molecular tunneling junctions, but it is incompatible with complementary metal-oxide-semiconductor fabrication because it forms deep level traps in silicon. Palladium electrodes do not contaminate silicon, and also give higher tunnel current signals in the molecular tunnel junctions that we have studied. The result is cleaner signals in a recognition-tunneling junction that recognizes the four natural DNA bases as well as 5-methyl cytosine, with no spurious background signals. More than 75% of all the recorded signal peaks indicate the base correctly.

Mucormycosis of Maxilla: An Enigma to the Clinician.

Mucormycosis is an acute opportunistic infection caused by a saprophytic fungus found in the soil, decaying fruits, and vegetables. It is a rapidly progressing fungal infection mainly seen in nose and its surrounding sinuses due to inhalation of the spores of fungus from the contaminated areas. If not diagnosed and treated early, it can be life-threatening. A case of a 60-year male farmer is reported with an extensive spread of the fungal infection involving alveolar bone of maxilla, zygomatic process, and the right orbit. The radiographs demonstrated alveolar, palatal, and zygomatic bone destruction. The diagnosis of mucormycosis was made through clinical, radiographic, and histopathologic findings. An early diagnosis and treatment with antifungal drugs like amphotericin B and surgical resection can improve the prognosis. Key Words: Mucormycosis, Maxilla, Zygomatic bone, Antifungal.

Intraoral osseous choriostoma---Case report and review on its biological occurrence.

The terminology choriostoma describes a tumor-like lesion belonging to hamartomatous group of pathology, that is, normal tissue found in abnormal location. Osseous choriostomas in oral cavity are rare and mostly the cases have been reported in tongue but rarely arising from the interdental gingiva. There are various pathological entities arising from gingiva that give a thought of wider differential diagnosis starting from inflammatory to traumatic origin. Hamartomas in oral cavity are very rare which can definitely be attributed to the sparse literature which leads to misdiagnosis as well failure to understand its biology. In this report, we present a case of osseous choriostoma arising from interdental gingiva in a young female patient in the lower arch.

Proliferative verrucus leukoplakia: A case series.

Oral proliferative verrucous leukoplakia (OPVL) is a rare form of oral leukoplakia first reported in 1985. It is a longterm progressive condition, which develops initially as a white plaque of hyperkeratosis that eventually becomes a multifocal disease with confluent, exophytic, and proliferative features. It has no racial preference with female predilection, associated with various factors including human papillomavirus (HPV) association, genetic susceptibility, and long-standing low-grade traumatic factors. The malignancy transformation rate varies from 0.13 to 17.5% with frequent recurrences. Here, we have reported two cases of PVL seen over the tongue and palate. It is confirmed by clinical and histopathological features and treated with Vitamin A and its supplements and a long-term follow-up showed no recurrence, and hence, Vitamin A has proven as a potent treatment option of PVL by its antioxidant and epithelialization property.

Accuracy and Safety of Novel Designs for Phase I Drug-Combination Oncology Trials.

Despite numerous innovative designs having been published for phase I drug-combination dose finding trials, their use in real applications is rather limited. As a working group under the American Statistical Association Biopharmaceutical Section, our goal is to identify the unique challenges associated with drug combination, share industry's experiences with combination trials, and investigate the pros and cons of the existing designs. Toward this goal, we review seven existing designs and distinguish them based on the criterion of whether their primary objectives are to find a single maximum tolerated dose (MTD) or the MTD contour (i.e., multiple MTDs). Numerical studies, based on either industry-specified fixed scenarios or randomly generated scenarios, are performed to assess their relative accuracy, safety, and ease of implementation. We show that the algorithm-based 3+3 design has poor performance and often fails to find the MTD. The performance of model-based combination trial designs is mixed: some demonstrate high accuracy of finding the MTD but poor safety, while others are safe but with compromised identification accuracy. In comparison, the model-assisted designs, such as BOIN and waterfall designs, have competitive and balanced performance in the accuracy of MTD identification and patient safety, and are also simple to implement, thus offering an attractive approach to designing phase I drug-combination trials. By taking into consideration the design's operating characteristics, ease of implementation and regulation, the need for advanced infrastructures, as well as the risk of regulatory acceptance, our paper offers practical guidance on the selection of a suitable dose-finding approach for designing future combination trials.

Combined R2* and diffusion tensor imaging changes in the substantia nigra in Parkinson's disease.

Recent magnetic resonance imaging studies suggest an increased transverse relaxation rate and reduced diffusion tensor imaging fractional anisotropy values in the substantia nigra in Parkinson's disease. The transverse relaxation rate and fractional anisotropy changes may reflect different aspects of Parkinson's disease-related pathological processes (ie, tissue iron deposition and microstructure disorganization). This study investigated the combined changes of transverse relaxation rate and fractional anisotropy in the substantia nigra in Parkinson's disease. High-resolution magnetic resonance imaging (T2-weighted, T2*, and diffusion tensor imaging) were obtained from 16 Parkinson's disease patients and 16 controls. Bilateral substantia nigras were delineated manually on T2-weighted images and coregistered to transverse relaxation rate and fractional anisotropy maps. The mean transverse relaxation rate and fractional anisotropy values in each substantia nigra were then calculated and compared between Parkinson's disease subjects and controls. Logistic regression, followed by receiver operating characteristic curve analysis, was employed to investigate the sensitivity and specificity of the combined measures for differentiating Parkinson's disease subjects from controls. Compared with controls, Parkinson's disease subjects demonstrated increased transverse relaxation rate (P<.0001) and reduced fractional anisotropy (P=.0365) in the substantia nigra. There was no significant correlation between transverse relaxation rate and fractional anisotropy values. Logistic regression analyses indicated that the combined use of transverse relaxation rate and fractional anisotropy values provides excellent discrimination between Parkinson's disease subjects and controls (c-statistic=0.996) compared with transverse relaxation rate (c-statistic=0.930) or fractional anisotropy (c-statistic=0.742) alone. This study shows that the combined use of transverse relaxation rate and fractional anisotropy measures in the substantia nigra of Parkinson's disease enhances sensitivity and specificity in differentiating Parkinson's disease from controls. Further studies are warranted to evaluate the pathophysiological correlations of these magnetic resonance imaging measurements and their effectiveness in assisting in diagnosing Parkinson's disease and following its progression.

Therapeutic effects of hyperbaric oxygen: integrated review.

Hyperbaric oxygen therapy refers to inhalation of pure oxygen in a closed chamber. Hyperbaric oxygen has a therapeutic effect in numerous pathological conditions, such as decompression sickness, arterial gas embolism, carbon monoxide poisoning and smoke inhalation, osteomylitis, osteoradionecrosis and wound healing. Hyperbaric oxygen therapy is used for treating underlying hypoxia. This review indicates the action of hyperbaric oxygen on biochemical and various physiological changes in cellular level. Narrative review covers the current indications and contraindications of hyperbaric oxygen therapy. The review also focuses on the therapeutic effects of hyperbaric oxygen pretreatment and precondition in different pathological conditions. The complications and side effects of hyperbaric oxygen therapy are discussed.

On the Origin of E-Selectivity in the Ring-Opening Metathesis Polymerization with Molybdenum Imido Alkylidene N-Heterocyclic Carbene Complexes.

The understanding and control of stereoselectivity is a central aspect in ring-opening metathesis polymerization (ROMP). Herein, we report detailed quantum chemical studies on the reaction mechanism of E-selective ROMP of norborn-2-ene (NBE) with Mo(N-2,6-Me2-C6H3)(CHCMe3)(IMes)(OTf)2 (1, IMes = 1,3-dimesitylimidazol-2-ylidene) as a first step to stereoselective polymerization. Four different reaction pathways based on an ene syn or ene anti approach of NBE to either the syn- or anti-isomer of the neutral precatalyst have been studied. In contrast to the recently established associative mechanism with a terminal alkene, where a neutral olefin adduct is formed, NBE reacts directly with the catalyst via [2 + 2] cycloaddition to form molybdacyclobutane with a reaction barrier about 30 kJ mol-1 lower in free energy than via the formation of a catalyst-monomer adduct. However, the direct cycloaddition of NBE was only found for one out of four stereoisomers. Our findings strongly suggest that this stereoselective approach is responsible for E-selectivity and point toward a substrate-specific reaction mechanism in olefin metathesis with neutral Mo imido alkylidene N-heterocyclic carbene bistriflate complexes.