Injectable, self-healing mesoporous silica nanocomposite hydrogels with improved mechanical properties.

Self-healing hydrogels have emerged as promising biomaterials in regenerative medicine applications. However, an ongoing challenge is to create hydrogels that combine rapid self-healing with high mechanical strength to make them applicable to a wider range of organs/tissues. Incorporating nanoparticles within hydrogels is a popular strategy to improve the mechanical properties as well as to provide additional functionalities such as stimuli responsiveness or controlled drug delivery, further optimizing their use. In this context, mesoporous silica nanoparticles (MSNs) are promising candidates as they are bioactive, improve mechanical properties, and can controllably release various types of cargo. While commonly nanoparticles are added to hydrogels as filler component, in the current study we developed thiol surface-functionalized MSNs capable of acting as chemical crosslinkers with a known hydrophilic polymer, polyethylene glycol (PEG), through dynamic thiol-disulfide covalent interactions. Due to these dynamic exchange reactions, mechanically strong nanocomposites with a storage modulus of up to 32 ± 5 kPa compared to 1.3 ± 0.3 kPa for PEG hydrogels alone, with rapid self-healing capabilities, could be formed. When non-surface modified MSNs were used, the increase in storage modulus of the hydrogels was significantly lower (3.4 ± 0.7 kPa). In addition, the nanocomposites were shown to degrade slowly over 6 weeks upon exposure to glutathione while remaining intact at physiological conditions. Together, the data argue that creating nanocomposites using MSNs as dynamic crosslinkers is a promising strategy to confer mechanical strength and rapid self-healing capabilities to hydrogels. This approach offers new possibilities for creating multifunctional self-healing biomaterials for a wider range of applications in regenerative medicine.

A rare tumor of the gallbladder: Small cell neuroendocrine carcinoma.

Small cell neuroendocrine carcinoma of the gallbladder is a rare, aggressive malignancy that does not yet have a standard treatment protocol. In this case report, we aimed to share our experience about a 74-year-old male patient presented to our clinic with the complaint of episodic abdominal pain and underwent cholecystectomy under elective conditions due to a polyp with a diameter of 4 cm visualized in the gallbladder on ultrasound and diagnosed with neuroendocrine carcinoma as a result of histopathological examination.

Examination of foramen tympanicum: an anatomical study using cone-beam computed tomography.

BACKGROUND: The foramen tympanicum (FT) is an osseous dehiscence of the temporal bone and usually closes by the age of 5 years. The foramen is located posteromedial to the temporomandibular joint and anteroinferior of the external auditory canal. The aim of this study is to define the prevalence, location and size of the foramen. MATERIALS AND METHODS: We retrospectively examined 200 cone-beam computed tomography (CBCT) images (400 ears). We used a CBCT dental imaging system (GALILEOS, Sirona Dental Systems, Bensheim, Germany) working at 15-30 mA and 98 kV. We noted size and location (unilateral and bilateral) of the present FT. RESULTS: Foramen tympanicum was determined in 11.5% of 200 patients (they had FT at least on one side of the head). This was bilateral in 5 (2.5%) patients. Prevalence of the FT was significintly higher in females (8%) than in males (3.5%). FT was found more frequently on the left side (7.5%) than on the right side (4%). Mean axial diameter was 1.13 mm (range 0.23-4.43 mm), and mean sagittal diameter was 1.44 mm (range 0.22-3.99 mm). CONCLUSIONS: Considering that FT was present in 11.75% of patients, radiologists and clinicians should be aware of the possible presence of this defect. It is known that this developmental dehiscence may cause herniation of temporomandibular joint, formation of salivary otorrhea, and spread of tumour or infection to the infratemporal fossa from external auditory canal. This study showed that CBCT may be preferred for imaging these conditions. (Folia Morphol 2018; 77, 2: 335-339).

Ethnic differences in bone geometry between White, Black and South Asian men in the UK.

Relatively little is known about the bone health of ethnic groups within the UK and data are largely restricted to women. The aim of this study was to investigate ethnic differences in areal bone mineral density (aBMD), volumetric bone mineral density (vBMD), bone geometry and strength in UK men. White European, Black Afro-Caribbean and South Asian men aged over 40years were recruited from Greater Manchester, UK. aBMD at the spine, hip, femoral neck and whole body were measured by DXA. Bone geometry, strength and vBMD were measured at the radius and tibia using pQCT at the metaphysis (4%) and diaphysis (50% radius; 38% tibia) sites. Adjustments were made for age, weight and height. Black men had higher aBMD at the whole body, total hip and femoral neck compared to White and South Asian men independent of body size adjustments, with no differences between the latter two groups. White men had longer hip axis lengths than both Black and South Asian men. There were fewer differences in vBMD but White men had significantly lower cortical vBMD at the tibial diaphysis than Black and South Asian men (p<0.001). At the tibia and radius diaphysis, Black men had larger bones with thicker cortices and greater bending strength than the other groups. There were fewer differences between White and South Asian men. At the metaphysis, South Asian men had smaller bones (p=0.02) and lower trabecular vBMD at the tibia (p=0.003). At the diaphysis, after size-correction, South Asian men had similar sized bones but thinner cortices than White men; measures of strength were not broadly reduced in the South Asian men. Combining pQCT and DXA measurements has given insight into differences in bone phenotype in men from different ethnic backgrounds. Understanding such differences is important in understanding the aetiology of male osteoporosis.

An unusual foreign body in the maxillary sinus: Dental impression material.

Foreign bodies in paranasal sinuses are very rare and most of them are encountered in the maxillary sinus. These foreign bodies may be organic or inorganic and can enter the maxillary sinus through an oro-antral fistula. The oro-antral fistula is formed by a break in the bony segment of the maxillary sinus floor and usually arises subsequent to maxillary premolar and molar extractions. A 63-year-old female patient evaluated for a nonhealing, left, toothless palate lesion and chronic headache occurring over 4 years. Radiography and computed tomography revealed bone discontinuity in the left floor of the maxillary sinus and calcifications within the antrum. A blue foreign body, later identified as dental impression material, was removed by intranasal endoscopy. A careful oral examination is recommended prior to prosthetic restorations. In addition, paranasal sinus foreign bodies should be surgically removed to prevent secondary soft tissue reactions.

Diagnostic value of terminal ileum biopsies in patients with abnormal terminal ileum mucosal appearance.

OBJECTIVE: To investigate the necessity of obtaining routine ileal biopsy during colonoscopy in the patients with abnormal terminal ileum mucosal appearance if the inflammatory bowel disease is not considered. MATERIAL AND METHODS: A retrospective analysis was performed for 57 patients who were referred to a private hospital for colonoscopy between January 2008 and February 2009, in whom terminal ileum intubation was achieved and an abnormal appearance was observed. RESULTS: There were 33 men and 24 women; the mean age was 44.12±11.42 years. In 22 patients, the abnormality was ulcers and/or erosions. In 10 patients, there were mucosal nodularity and in 24, the finding was erythema. The time to reach to ileum from cecum was 28.78±24.30 s. The mean length of the examined ileum was 12.93±6.05 cm. There was no difference between groups according to distance covered in the ileum for diagnostic yield, but going further than 2 cm was important. CONCLUSION: There should be no need to obtain routine biopsy in patients with abnormal terminal ileum mucosa appearance, when inflammatory bowel disease is not considered. In these patients, histopathology also reveals non-specific ileitis. Furthermore, in these patients, the macroscopic pathological diagnosis overlaps the histopathology, and it has a low diagnostic yield and lower clinical significance.

Oral hygiene and oral flora evaluation in psychiatric patients in nursing homes in Turkey.

CONTEXT: The World Health Organization has stated that psychiatric patients are a group of people who have oral and dental illnesses. AIMS: The aims of this study were to document the oral hygiene of individuals with chronic psychiatric illness, to determine the extraoral and intraoral findings, to detect the dominant microorganisms in oral flora, and to inform clinicians of these findings. SETTINGS AND DESIGN: The study included 100 patients (69 men and 31 women) with different psychiatric illnesses living in a nursing home. They were 19-96 years old (median, 48 years). SUBJECTS AND METHODS: The participants completed a questionnaire about patients' oral health. They underwent extraoral and intraoral examinations. Two swab samples were obtained from the oral mucosa of these patients. Gram preparations were analyzed for leukocytes, bacteria, and yeast. STATISTICAL ANALYSIS USED: Chi-square test and z-test were used. RESULTS: All patients (100%) had the necessary equipment for oral hygiene; however, many (43%) patients had poor oral hygiene. There was a high prevalence of xerostomia (56%) and fissured tongue (61.4%) (among other tongue anomalies). The most commonly isolated microorganisms were coagulase-negative Staphylococcus0 (35.9%), Streptococcus spp. (30.3%), nondiphtheroid Bacilli (16.9%), Staphylococcus aureus (2.3%), Candida spp. (11.8%), and Gram-negative Bacilli (2.8%). CONCLUSIONS: The oral hygiene of most patients was insufficient. The presence of Gram-negative Bacilli growth in the oral flora can be explained by poor hand hygiene. These findings suggest that it is useful to educate individuals about oral hygiene and hand hygiene and to inform the staff and families about this issue.

A case report on a nasolabial cyst presenting with a nasolacrimal sac cyst.

Nasolabial cysts are rare, nonodontogenic soft tissue developmental cysts that occur in the maxillary lip and nasal alar regions. Patients with this type of cyst generally presents with an asymptomatic soft swelling that may obliterate the nasolabial fold, elevate the nasal ala or the floor of the nose and fill the labial vestibule intraorally. The exact origin of nasolabial cysts is uncertain. The seed theory suggests that these cysts develop from a misplaced epithelium of the nasolacrimal duct because of their similar location and histologic appearance. This report aimed to present a case of nasolabial cyst presenting with a nasolacrimal sac cyst.

Echo-guided pericardiocentesis in patients with clinically significant pericardial effusion. Outcomes over a 10-year period.

BACKGROUND: The purpose of the present study is to evaluate current echocardiographically (echo)-guided pericardiocentesis practice with regard to procedural success, complication rate, etiological causes, and outcomes of patients with clinically significant pericardial effusion. PATIENTS AND METHODS: Patients who underwent echo-guided pericardiocentesis between January 2004 and February 2014 were identified using an institutional code for the procedure. Other complementary data were obtained by interviewing patients or their relatives (directly or by telephone) and by searching the social security death index. RESULTS: A total of 301 patients were identified. The pericardium was approached via the subcostal (85 %) or apical (15 %) route under echo guidance in all procedures. The success rate was 97 %, with an intervention-requiring complication rate of 1.3 %. No patient died from complications. The most common etiology was malignancy (n = 84, 28 %). Patients were followed-up for a median of 35 months. Median survival for patients with malignant effusion was 5.9 months compared with 54 months for those with nonmalignant effusion. CONCLUSIONS: Echo-guided pericardiocentesis has a high success and low complication rate in current practice. Among etiologies, malignancy remains the most common cause of clinically significant pericardial effusion and is associated with a poor prognosis.

Evaluation of traumatic dental injuries in a group of Turkish population.

BACKGROUND: Traumatic dental injuries (TDIs) are significant clinical problems that may have complex etiologies and may cause physical and physiological impairment. AIM: The aim of this study was to determine the demographic and clinical characteristics of TDIs in a group of Turkish subjects. MATERIALS AND METHODS: The prevalence of TDIs and the pattern of traumatized teeth were studied in relation to age, gender, cause, location, and type of injury. This study was carried out to include all age groups and teeth. TDIs were recorded using the World Health Organization classification modified by Andreasen et al. RESULTS: The prevalence of TDIs was found to be 4.4% (255 injured patients/5800 presented patients), and the injuries were most commonly observed in the age group of 11-20 years. Males were more affected than females (males, 153; females, 102). The most common cause of traumatic injury was falling (68.2%), and the most common place of trauma was outdoors (56.1%). 4, 7% of patients injured because of their systemic diseases. The most frequently injured teeth were the upper central incisors (primary teeth, 64.5%; permanent teeth, 72.5%), and the most common type of dental injury was uncomplicated crown fracture in both primary (63%) and permanent dentition (47%). CONCLUSION: In the surveyed population, the prevalence of TDIs was found to be low. However, the teacher and family of adolescents and the caregivers of patients with some systemic diseases like epilepsy should be warned about TDIs.

Primary double teeth and their effect on permanent successors.

AIM: Understanding the effects of primary double tooth (PDT) on permanent successors is important to ensure healthy permanent occlusion and aesthetics. The aim of this study is to determine the prevalence and type of PDT, their effect on permanent successors, and the accompanying dental anomalies/pathologies in a Turkish population. MATERIALS AND METHODS: Study design: The records of 63 PDTs in 54 healthy Caucasian children among 10,000 patients were investigated. PDTs were classified according to Aguilo's classification. RESULTS: The prevalence of PDT was 0.6%. Of the 63 PDTs, 14.3% were type I, 11.1% were type II, 31.7% were type III, and 41.3% were type IV; one (1.6%) was a triple tooth. Aplasia of the permanent lateral incisor was observed most frequently in association with type I (56%) PDT. All PDTs associated with a supernumerary permanent tooth were type IV. Dental anomalies/pathologies such as odontoma, talon cusp were observed. Caries involvement was observed most frequently in type IV (58.3%) PDT. STATISTICS: The chi-squared test was used to determine whether successor aplasia depended on PDT type, and contingency coefficients (%) were calculated to determine the degree of association between aplasia and PDT type. CONCLUSION: Clinicians should assess PDT clinically and radiographically to determine whether they are associated with aplasia of permanent lateral incisors (type I) or supernumerary permanent teeth (type IV). Type IV of PDT should be sealed with sealant or resin.

Neuropeptide y attenuates stress-induced bone loss through suppression of noradrenaline circuits.

Chronic stress and depression have adverse consequences on many organ systems, including the skeleton, but the mechanisms underlying stress-induced bone loss remain unclear. Here we demonstrate that neuropeptide Y (NPY), centrally and peripherally, plays a critical role in protecting against stress-induced bone loss. Mice lacking the anxiolytic factor NPY exhibit more anxious behavior and elevated corticosterone levels. Additionally, following a 6-week restraint, or cold-stress protocol, Npy-null mice exhibit three-fold greater bone loss compared to wild-type mice, owing to suppression of osteoblast activity. This stress-protective NPY pathway acts specifically through Y2 receptors. Centrally, Y2 receptors suppress corticotropin-releasing factor expression and inhibit activation of noradrenergic neurons in the paraventricular nucleus. In the periphery, they act to control noradrenaline release from sympathetic neurons. Specific deletion of arcuate Y2 receptors recapitulates the Npy-null stress response, coincident with elevated serum noradrenaline. Importantly, specific reintroduction of NPY solely in noradrenergic neurons of otherwise Npy-null mice blocks the increase in circulating noradrenaline and the stress-induced bone loss. Thus, NPY protects against excessive stress-induced bone loss, through Y2 receptor-mediated modulation of central and peripheral noradrenergic neurons.

Neuropeptide Y mediates the short-term hypometabolic effect of estrogen deficiency in mice.

BACKGROUND: Estrogen deficiency increases body weight or total and central adiposity and decreases energy expenditure. Hypothalamic neuropeptide Y (NPY) expression is altered by estrogen deficiency in rodents, but the long-term consequences on energy homeostasis are unknown. OBJECTIVE: To investigate the role of NPY in the changes in energy expenditure and physical activity, as well as the associated changes in body weight and composition in response to short-term and long-term estrogen deficiency. DESIGN: Sham and ovariectomy (OVX) operations were performed at 8 weeks of age in wild-type (WT) and NPY(-/-) mice. Energy expenditure, physical activity, body composition and weight, as well as food intake were measured at 10-18 days (short-term) and 46-54 days (long-term) after OVX. RESULTS: OVX influences energy homeostasis differently at early compared with later time-points. At the early but not the late time point, OVX in WT mice reduced oxygen consumption and energy expenditure and tended to reduce resting metabolic rate. Interestingly, these effects of short-term estrogen deficiency were ablated by NPY deletion, with NPY(-/-) mice exhibiting significant increases in energy expenditure and resting metabolic rate. In addition to these hypermetabolic effects, OVX NPY(-/-) mice exhibited significantly lower body weight and whole-body fat mass relative to OVX WT controls at the short-term but not the long-term time point. Food intake and physical activity were unaltered by OVX, but NPY(-/-) mice exhibited significant reductions in these parameters relative to WT. CONCLUSION: The effects of estrogen deficiency to reduce energy metabolism are transient, and NPY is critical to this effect as well as the early OVX-induced obesity.

Intramuscular hemangioma presenting with multiple phleboliths: a case report.

A rare case of intramuscular hemangioma of the masseter muscle with multiple phleboliths is described, highlighting features evident in plain radiography, ultrasound, and magnetic resonance imaging (MRI). A 21-year-old woman presented with a complaint of swelling of the right masseter muscle. A plain radiograph from the soft tissue of the right cheek showed a large number of round, target-like radiopacities that varied in size. Ultrasound revealed a lobulated cystic lesion in the right masseter muscle with increased echogenicity. MRI showed a space-occupying lesion in the right masseter muscle, which was isointense on T1-weighted image close to the muscle tissue and hyperintense on T2-weighted image, containing fields with no signal septations. A plain soft tissue radiograph can demonstrate phleboliths and aid in the diagnosis of an intramuscular hemangioma. In addition, nonionized techniques such as ultrasound and MRI can provide useful information to clinicians regarding the location of calcifications and the structure of masses.

Multiple pulp stones: a case report.

Pulp stones are usually found in the pulp chamber. Radiographically, they appear as radiopaque structures in the pulp chambers or root canals of individual teeth. Generalized pulp stones throughout the dentition are usually associated with systemic or genetic disorders of the dentine. This report presents an unusual case of a 13-year-old girl with generalized pulp stones with clinically normal crowns. The patient's main complaint was a crossbite affecting all permanent canines. Radiographic examination revealed multiple pulp stones and several teeth with atypically shaped roots. Orthodontic treatment, gingivoplasty, and esthetic restorations were performed, thus using a multidisciplinary approach to establish functionally and esthetically sound dentition.

Myocardial perfusion alterations observed months after radiotherapy are related to the cellular damage.

AIM: Myocardial perfusion scintigraphy (MPS) is one of the widely used tools to follow developing radiation-induced heart disease (RIHD). But the clinical significance of MPS defects has not been fully understood. We have investigated the biodistribution alterations related to perfusion defects following radiotherapy (RT) and showed coexisting morphologic changes. ANIMALS, METHODS: A total of 18 Wistar rats were divided into three groups (1 control and 2 irradiated groups). A single cardiac 20 Gy radiation dose was used to induce long term cardiac defects. Biodistribution studies with technetium (99mTc) sestamibi and histological evaluations were performed 4 and 6 months after irradiation. The percent radioactivity (%ID/g) was calculated for each heart. For determination of the myocardial damage, positive apoptotic cardiomyocytes, myocardial cell degeneration, myocardial fibrosis, vascular damage and ultrastructural structures were evaluated. RESULTS: Six months after treatment, a significant drop of myocardial uptake was observed (p < 0.05). Irradiation-induced apoptosis rose within the first 4 months after radiation treatment and were stayed elevated until the end of the observation period (p < 0.05). Also, the irradiation has induced myocardial degeneration, perivascular and interstitial fibrosis in the heart at the end of six and four months (p < 0.01). The severity and extent of myocardial injury has became more evident at the end of six month (p < 0.05). At ultrastructural level, prominent changes have been observed in the capillary endothelial and myocardial cells. CONCLUSION: Our findings suggest that the reduced rest myocardial perfusion, occurring months after the radiation, indicates a serious myocard tissue damage which is characterized by myocardial degeneration and fibrosis.

Double dens invaginatus: report of three cases.

Dens invaginatus results from an infolding of the outer surface of a tooth. The clinical importance of dens invaginatus results from the risk of pulpal disease. So, all clinicians should be aware of this anomaly. The presence of double dens invaginatus is extremely rare. This article presents three cases of double dens invaginatus in permanent maxillary lateral incisors, one with preventive restoration on its palatal surface. They were classified as double dens invaginatus because of two enamel lined invaginations presented in the crowns of these teeth.

Extrafollicular adenomatoid odontogenic tumor of the mandible: report of a case.

The purpose of this study was to report an extrafollicular adenomatoid odontogenic tumor in the mandibular anterior region in a patient. A 15 year-old female with a painless swelling in the mandibular anterior region was referred to our clinic. Fine needle aspiration yielded no fluid. Periapical, panoramic and computer tomography scans showed circumscribed radiolucent area with fine calcifications. The lesion was totally enucleated and the teeth 31, 32 were removed. The rarity of adenomatoid odontogenic tumor may be associated with its slowly growing pattern and symptomless behavior. Therefore, it should be distinguished from more common lesions of odontogenic origin in routine dental examinations.