Unilateral triple mandibular canal with double mandibular foramen: cone-beam computed tomography findings of an unexpected anatomical variant.

The mandibular canal is a bony channel located within the spongiosa of the mandible. The main structure contained in the mandibular canal is the inferior alveolar nerve. The inferior alveolar nerve is a very important structure that requires due consideration during dental or surgical procedures involving the mandible. Therefore, a detailed morphological analysis of the mandibular canal should be carried out before any surgical procedure in the mandibular region in order to avoid complications and to reduce the risk of inadequate local nerve blocking. The human mandible typically has a single mandibular canal on each side; however, accessory mandibular canals have been described previously in the literature. The most common variant of the mandibular canal is the bifid mandibular canal, which has a prevalence ranging from 10% to 66% on cone-beam computed tomography (CBCT) examinations. A rare variant of bifid mandibular canal is the trifid canal, accounting for less than 6% of all bifid canals. In some cases, the bifid and trifid mandibular canals are associated with a double mandibular foramen, which is a rare anatomical variant with a reported incidence of 1.35% on CBCT images. Herein, we present the interesting CBCT images of an unexpected anatomical variant characterised by unilateral triple mandibular canal with double mandibular foramen in a young Caucasian woman.

Different subsets of circulating angiogenic cells do not predict bronchopulmonary dysplasia or other diseases of prematurity in preterm infants.

Bronchopulmonary dysplasia (BPD) is a chronic lung disease occurring in very and extremely preterm infants undergoing mechanical ventilation. Given the altered lung vascular growth characterizing BPD, circulating angiogenic cells could be useful biomarkers to predict the risk. The objective of the study was to determine whether the percentages of circulating angiogenic cells (CD34+VEGFR-2+, CD34+CD133+VEGFR-2+, and CD45-CD34+CD133+VEGFR-2+ cells), assessed in the peripheral blood at birth by flow cytometry, could be used as markers for the risk of BPD. In one-hundred and forty-two preterm neonates (gestational age less than 32 weeks and/or birth weight less than 1500 g) admitted to our tertiary care Neonatal Intensive Care Unit between 2006 and 2009, we evaluated the percentages of circulating angiogenic cells at birth, at 7 days, and, in a subset of infants (n=40), at 28 days of life. The main outcome was the correlation between cell counts at birth and the subsequent risk of developing BPD. In our study, all the three cell populations failed to predict the development of BPD or other diseases of prematurity. We suggest that these cells cannot be used as biomarkers in preterm infants, and that research is needed to find other early predictors of BPD.

[Neonatal sepsis: new preventive strategies]. / Sepsi neonatali: nuove strategie preventive.

More than one million neonatal deaths every year in the world are attributable to infection. In nurseries, infections occur with a reported incidence of 0.3-3%; in Neonatal Intensive Care Units (NICUs) the reported incidence is 7-24.5%, and up to 40% in newborns with birth weight less than 1000 g or gestational age at birth <28 weeks. Sepsis is the most severe and frequent infection, accounting for 45-55% of all infections. Several practices have been demonstrated to be effective in reducing the incidence of infection in NICUs, including hand hygiene practices, correct management of central venous catheters (CVC), accurate diagnostic strategies and correct use of antimicrobial drugs. Despite the reduction in the incidence of infection after implementation of these practices, nosocomial infections are still a relevant problem, with high mortality and morbidity rates in hospitalized newborns, especially preterm newborns. Searching for new strategies to further reduce the incidence of nosocomial sepsis in NICUs is a priority of clinical research. New and promising strategies for the prevention of nosocomial infection in NICU include: lactoferrin administration, early identification of infants at risk of infection by means of specific markers (e.g. mannose binding lectin), heparin use for the prevention of CVC-related infections, judicious use of antibiotics, and prevention of fungal sepsis with antifungal agents. On the contrary, recent studies demonstrated that the use of specific immunoglobulins directed against different staphylococcal antigens is not effective in preventing neonatal sepsis.

Use and misuse of antibiotics in the neonatal intensive care unit.

Severe infections represent the main cause of neonatal mortality accounting for more than one million neonatal deaths worldwide every year. Antibiotics are the most commonly prescribed medications in neonatal intensive care units (NICUs) and in industrialized countries about 1% of neonates are exposed to antibiotic therapy. Signs and symptoms of sepsis are nonspecific, and empiric antimicrobial therapy is promptly initiated after obtaining appropriate cultures in order to prevent deleterious consequences. However, many preterm infants who do not have infection receive antimicrobial agents during hospital stay and antibiotic treatment in the setting of negative cultures can have serious adverse effects like: promotion of bacterial antibiotic resistance, alteration of gut colonization, increase risk of Candida colonization and subsequent invasive candidiasis, increase risk of death, necrotizing enterocolitis and late-onset sepsis. Appropriate choice of antimicrobial agents and optimal duration of therapy in neonates with suspected or culture-proven sepsis is essential in order to prevent serious consequences. Moreover the establishment of an antibiotic stewardship programme in the NICUs is the best way of ensuring neonatal infections remain treatable while efforts are made for the developing of optimal antibiotic prescribing.

Circulating endothelial progenitor cells and diseases of the preterm infant.

During the last decade, multiple techniques have been developed to isolate and quantify human endothelial progenitor cells (EPCs). In parallel, a number of studies have applied these methodologies to investigate the number and function of circulating EPCs in adult diseases characterized by vascular dysfunction. However, very little is known about different subtypes of EPCs during gestation, during the neonatal age or in neonatal diseases. Initial evidence supports the hypothesis that circulating angiogenic cells may play an important role during development, and attention has particularly focused in clarifying the function of EPCs in lung vascular development, and the role of the impairment of EPC mobilization and homing in hyperoxia-induced lung injury characteristic of bronchopulmonary dysplasia. Among different subtypes of EPCs, both the role of angiogenic mononuclear cells (triple-positive CD34+CD133+VEGFR-2+ cells and colony forming unit-Hill cells) and endothelial colony forming cells (ECFCs) in physiological vascular development and during neonatal diseases need to be elucidated. A better understanding of EPC biology during gestation, during the neonatal age and in preterm infants will unravel the pathologic basis of bronchopulmonary dysplasia and other preterm and term neonatal diseases characterized by a prominent defect in vascular growth, including retinopathy of prematurity and persistent pulmonary hypertension of the newborn.

Preterm newborns are provided with triggering receptor expressed on myeloid cells-1.

Triggering receptor expressed on myeloid cells-1 (TREM-1) and soluble fraction (sTREM-1) are useful markers of infection in adults. Neonates, especially preterm infants, are exposed to high risk of sepsis due to the immature immune system and few data are available regarding TREM-1, mainly focused on the soluble form. We therefore decided to investigate the baseline assessment of TREM-1, membrane and soluble receptors, in preterm newborns without clinical or microbiological evidence of infection, in order to precociously measure the possible changes due to sepsis and compare them to the obtained reference values. Fifty-nine newborns were enrolled in the study. Median and Interquartile range of TREM-1 were: in monocytes 96 percent with 71 Mean Fluorescence Intensity (50-94); in PMNs: 80 percent (68-87); soluble TREM-1: 29.1 pg/ml (14.55-103.93). Monocyte expression and soluble TREM-1 concentrations appeared comparable to healthy adults, while not all PMNs expressed this receptor, possibly due to their immaturity. Birth weight negatively correlated with sTREM-1, while there were no statistical significances with gestational age, maternal age, gender, mode of delivery, patent ductus arteriosus, intrauterine growth restriction, premature rupture of membranes and TREM-1 or sTREM-1. We also reported a statistical relationship between monocyte TREM-1 and surfactant administration and between sTREM-1 and antenatal steroid prophylaxis. Even if untrained, the neonatal immune system of preterm newborns is equipped with TREM-1 system, but further studies are needed to evaluate the functionality in newborns.

Case report. MRI findings of necrotizing sialometaplasia.

Necrotizing sialometaplasia (NS) is a benign self-limiting inflammatory disease of mucus-secreting glands, mainly involving the minor salivary glands. This lesion can mimic a malignant neoplasm, as more frequently it manifests as a submucosal swelling or as an ulcer of the palate. Awareness of the disease is crucial to avoid undue surgical treatment. We herewith report MR findings in a histologically proven case of NS.

Strategies for the prevention of hospital-acquired infections in the neonatal intensive care unit.

Nosocomial infections are among the leading causes of mortality and morbidity in neonatal intensive care units. Prevention of healthcare-associated infections is based on strategies that aim to limit susceptibility to infections by enhancing host defences, interrupting transmission of organisms by healthcare workers and by promoting the judicious use of antimicrobials. Several strategies are available and include: hand hygiene practices; prevention of central venous catheter-related bloodstream infections; judicious use of antimicrobials for therapy and prophylaxis; enhancement of host defences; skin care; and early enteral feeding with human milk.

Antibiotics in neonatal intensive care units (NICUs).

Antibiotics, the most effective tools against pathogens, are overused in neonatal intensive care units (NICUs). Prolonged and unnecessary empirical use of broad-spectrum antibiotics selects resistant bacteria and increases the risk of sever fungal infections. Judicious use of antibiotics and development of appropriate intervention strategies and policies in order to reduce antibiotic use should be a primary objective in all NICUs. The choice of the best empirical antibiotic regiment should be base on the age of the infant, on the clinical signs and on the pharmacokinetics of the drug, but the narrowest spectrum antibiotics should be used.

Growth-related properties and postgrowth phenomena in organic molecular thin films.

The problem of monitoring the structural and morphological evolutions of thin films of organic molecular materials during their growth by organic molecular beam epitaxy and in the postgrowth stage is addressed here by a combination of in situ optical reflectance anisotropy measurements, ex situ optical and morphological investigations, and theoretical simulation of the material optical response. For alpha-quaterthiophene, a representative material in the class of organic molecular semiconductors, the results show that molecules crystallize in the first stage of growth in metastable structures, even when deposition is carried out at room temperature. In the postdeposition stage, the film structure evolves within a few days to the known equilibrium structure of the low temperature polymorph. When deposition is carried out at low substrate temperatures, an evolution of the film morphology is also demonstrated.

Effect of static and dynamic disorder on exciton mobility in oligothiophenes.

The polarized optical absorption spectra of different quaterthiophene single crystals in the energy region of the exciton bands originating from the first molecular transition are reported as measured in the temperatures ranging from 7 to 140 K. The intrinsic higher mobility of the b-polarized 0-0 a(u) exciton both with respect to its replicas and to the a-polarized structures is demonstrated in high quality crystals at the lowest temperatures. The influence of structural disorder on mobility is discussed considering, for the different samples, the measured lineshape and linewidth of the absorption peaks, and the relative lineshift and intensity ratio between the 0-0 a(u) line and its first replica at the lowest temperature. The influence of dynamic disorder is discussed considering the lineshape and linewidth of the measured peaks as a function of temperature for both polarizations in the framework of the exciton-phonon coupling theory.

Measured Davydov splitting in oligothiophene crystals.

The polarized absorption spectra of single crystals of oligothiophenes in a wide spectral range are reported. The experimental procedure is discussed, underlying several details which are relevant to obtain reliable spectra particularly for samples of increasing thickness. On the basis of these considerations, it has been possible to fully detect the transition to the upper Davydov exciton originating from the first molecular state. The position and shape of the main exciton peak in these materials are compared and discussed, taking into consideration the molecular arrangement and the longitudinal contribution which depends on the transition moment orientation. The Davydov splitting values as deduced from the experimental data at room temperature are also reported either for the first vibronic replica or for the electronic transition as a whole. The difference between the purely transverse and the measured Davydov splitting is discussed.

Optical transverse excitation in quaterthiophene crystals by ultraviolet-visible internal and attenuated total reflection.

We report internal and attenuated total reflection of light at the interface between glass and a quaterthiophene crystal in the spectral region of the electronic transitions. The bands corresponding to the absorption of the a(u) and b(u) Frenkel exciton states are detected for different polarization of the incident light. In particular, the wave-normal vector being almost perpendicular to the b(u) transition dipole moment allows its transverse component to be accessed, whose excitation in conventional external reflection or transmission spectroscopies is forbidden.

Directional dispersion in absorbance spectra of oligothiophene crystals.

Due to the large oscillator strength of the first molecular transition in oligothiophenes, a strong directional dispersion of the b(u) exciton transition is expected originating from the macroscopic polarization field. Examining such dispersion unambiguously usually requires different faces to be accessible for the optical measurements. Alternatively, measurements carried out at different angles of incidence are met with intrinsic limits due to the peculiarities of wave propagation in such anisotropic systems. In order to demonstrate these limits along with the experimental difficulties involved, we examine refraction and absorption of light in these crystals and discuss the effects of directional dispersion on the absorbance spectra of quaterthiophene crystals.

Magnetically driven growth of anthracene thin films by organic molecular beam deposition.

The possible use of a static magnetic field during organic molecular beam deposition of thin molecular films for inducing some preferential growth is discussed and the magnetic properties of diamagnetic molecules and molecular crystals are recalled. Considering prototypical materials, namely anthracene molecules and potassium phthalate substrates, which interact and may give rise to polycrystalline films with specific orientations, we show that in the presence of a magnetic field the films display a macroscopic preferential orientation as a result of minimization of the magnetic energy contribution. A very good agreement between the results of optical spectroscopy, atomic force microscopy, and predictions made on the basis of the anisotropic magnetic susceptibility of anthracene is found.

Polarized absorption of quaterthiophene single crystals.

Polarized optical spectra of quaterthiophene single crystals are reported over a wide spectral range for different planes and angles of incidence corresponding to either transverse or mixed longitudinal/transverse wave propagation. From the absorbance and reflectance spectra the corresponding absorption coefficients are deduced. In the region of the first molecular transition, polarized exciton states of Frenkel origin are found to be responsible for a strong optical anisotropy and for the modification of the state of polarization during light propagation in the crystal. Transmission measurements with crossed polarizer and analyzer allow to clearly identify Frenkel replica of the principal transition.

Reflectivity and anisotropic optical functions of quaterthiophene single crystals.

Polarized reflectance spectra of quaterthiophene single crystals are reported with different angles and planes of incidence. The strong dependence of the spectral features on the experimental configuration is described by an orthorhombic model and the components of the complex diagonal dielectric tensor are given.

Intrinsic excitonic luminescence in odd and even numbered oligothiophenes.

The emission properties of crystalline oligothiophenes (OTs) are investigated and related to the different selection rules arising from the number of rings. In odd OT crystals the purely electronic emission is absent since the molecular A1-1B(1) transition dipoles cancel at the bottom of the excitonic band. On the contrary, in crystals of even OTs this transition is allowed due to the constructive interference of the off-axis components of the molecular transition dipole. It possesses a polarization in the herringbone plane and exhibits superradiant behavior.