Spatial and temporal dynamics and potential pathogenicity of fecal coliforms in coastal shallow groundwater wells.

Access to water through shallow groundwater wells is a common practice in coastal settlements. This, coupled with a lack of planning for wastewater disposal promotes fecal contamination of groundwater and poses a threat to human health. Here, the spatial and temporal dynamics of groundwater fecal contamination was evaluated during summer and winter (2013 and 2014) in a coastal protected area having a high touristic relevance (Cabo Polonio, Uruguay). Fecal coliforms (FC) abundance in groundwater was significantly higher during summer, related to an influx of ~ 1000 tourists per day. A significant spatial autocorrelation was found in 2014, when the abundance of FC in a well was influenced by its three nearest wells (Moran and Geary tests). The applied statistical models (mixed models) indicated that total phosphorus and organic matter were the variables significantly explaining FC abundance. The risk for human health was estimated using groundwater-extracted DNA and qPCR of genes encoding for E. coli virulence factors (stx1, stx2, and eae). Potential Shiga toxin-producing enteropathogenic and enterohemorrhagic pathotypes were detected, even at FC abundances ≤ 1 CFU (100 mL-1). Moreover, we found that contaminated groundwater reached the beach, being the presence of FC in sand detected even in winter and showing its highest frequency nearby groundwater wells consistently having high FC abundance (hot spots). Altogether, the results show that fecal contamination of shallow groundwater in Cabo Polonio involves a risk for human health that intensifies during summer (associated to a significant increase of tourists). This contamination also impacts the beach, where FC can remain through the whole year.

Repair of segmental mandibular bone defects in sheep using bone marrow stromal cells and autologous serum scaffold: a pilot study.

AIM: The aim of this study was to evaluate effective bone regeneration using an autologous serum scaffold (alone or seeded with autologous bone marrow-mesenchymal stem cells, BM-MSCs), when implanted in a 30 mm length segmental mandibular defect in sheep. MATERIALS AND METHODS: The bone defect was filled either with serum scaffold alone (control group; n = 5) or combined with BM-MSCs (experimental group; n = 10). Bone regeneration was determined at 12 (T12; 2 control sheep and 4 experimental sheep) and 32 weeks (T32; 3 control and 6 experimental sheep), as measured by computed and microcomputed tomography and histological examination. RESULTS: Two sheep of the Experimental group died after surgery. While complete bone union in the control group was only observed at T32, it was observed both at T12 (1/4 sheep) and T32 (3/4 sheep) in the experimental group. When properties/characteristics of new bone where compared, a better bone quality, similar to native bone, was observed in the scaffold combined with BM-MSCs. CONCLUSIONS: Based on these results, we conclude that the serum scaffold can promote efficient repair of large bone defects, but the combination with BM-MSCs accelerates this process, increasing significantly the amount and quality of bone formed.

Sinus mucosal thickening in bisphosphonate-related osteonecrosis of the jaws: a case-control study.

Osteonecrosis of the jaws is a clinically significant complication of bisphosphonate (BP) medications. Otherwise, the effects of BPs on oral soft tissue or cells remain unknown. The main objective of the present study was to determine whether the presence of sinus mucosal thickening was significantly related to BP-related osteonecrosis of the jaw (BRONJ). A case-control study was conducted on 32 patients who underwent treatment of BRONJ with conventional radiological investigations (panoramic radiographs) and computed tomography. The results indicated that patients with BRONJ had a 5.57-fold greater probability of presenting sinus mucosal thickening than controls. Although the existence of this thickening was more common in patients with advanced-stage disease or low levels of C-telopeptide-cross-linked type I collagen, no significant difference was observed between cases and controls. While considering the limitations inherent in the design and number of cases analyzed in our study, patients with osteonecrosis of the jaw were found to have a 5.57-fold greater probability of presenting sinus mucosal thickening (>3 mm) than healthy subjects.

Bisphosphonate-related osteonecrosis associated with dental implants: a microcomputed tomography study.

PURPOSE: The aims of this study were to quantify bone mineral density (BMD) and trabecular architecture of sequestra in patients with bisphosphonate-related osteonecrosis of the jaw (BRONJ) associated with dental implants and to assess if there are differences between trabecular bone in "implant loading-triggered" and "implant surgery-triggered" BRONJ. MATERIALS AND METHODS: Bone sequestra of 2 patients diagnosed with BRONJ associated with dental implants were scanned using high-resolution microcomputed tomography (microCT). Images were obtained at a voltage of 50 kV and 800 µA, and the specimens were scanned at 180 degrees with a single rotation step of 0.3, 1-mm aluminum filter, and a pixel size of 12 µm. The morphometric parameters examined were: BMD, ratio of bone volume/tissue volume (BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), trabecular separation (Tb.Sp), connectivity density (Conn.D, mm), degree of anisotropy, and the structural model index. RESULTS: BMD and BV/TV were higher in bone sequestration than in healthy bone. Tb.Sp was lower and Tb.N and Tb.Th were higher in the BRONJ group. Conn.D and Tb.N values were significantly high in implant surgery-triggered sequestrum but substantially low in sequestra caused by loading as compared with those of the control sample. CONCLUSIONS: MicroCT is useful for assessing bone sequestration of BRONJ associated to dental implants. The necrotic bone is similar to that described in conventional BRONJ.

Alternative treatments for oral bisphosphonate-related osteonecrosis of the jaws: a pilot study comparing fibrin rich in growth factors and teriparatide.

OBJECTIVE: The aim of this study is to describe and compare the evolution of recurrent bisphosphonate-related osteonecrosis of the jaws (BRONJ) in patients treated with plasma rich in growth factors or teriparatide. MATERIAL AND METHODS: Two different types of treatments were applied in patients diagnosed of recurrent BRONJ in a referral hospital for 1.100.000 inhabitants. In the group A, plasma rich in growth factors was applied during the surgery. In the group B, the treatment consisted in the subcutaneous administration of teriparatide. All the cases of BRONJ should meet the following conditions: recurrent BRONJ, impossibility of surgery in stage 3 Ruggiero classification and absence of diagnosed neoplastic disease. Clinical and radiographic evolution of the patients from both groups was observed. RESULTS: Nine patients were included, 5 in group A and 4 in group B. All the patients were women on oral bisphosphonate therapy for primary osteoporosis (5 patients) or osteoporosis-related to the use of corticosteroids (4 patients). Alendronate was the most common oral bisphosphonate associated with BRONJ in our study (four patients in group A and two in group B). The mean age was 72,8 years in the group A and 73,5 years in the group B. All the patients from group A showed a complete resolution of their BRONJ. Only one patient in the group B showed the same evolution. CONCLUSION: In our series, the plasma rich in growth factors showed better results than the teriparatide in the treatment of recurrent BRONJ.

Design, In Vitro Evaluation and In Vivo Biocompatibility of Additive Manufacturing Three-Dimensional Printing of ß beta-Tricalcium Phosphate Scaffolds for Bone Regeneration.

The reconstruction of bone deficiencies remains a challenge due to the limitations of autologous bone grafting. The objective of this study is to evaluate the bone regeneration efficacy of additive manufacturing of tricalcium phosphate (TCP) implants using lithography-based ceramic manufacturing (LCM). LCM uses LithaBone TCP 300 slurry for 3D printing, producing cylindrical scaffolds. Four models of internal scaffold geometry were developed and compared. The in vitro studies included cell culture, differentiation, seeding, morphological studies and detection of early osteogenesis. The in vivo studies involved 42 Wistar rats divided into four groups (control, membrane, scaffold (TCP) and membrane with TCP). In each animal, unilateral right mandibular defects with a total thickness of 5 mm were surgically performed. The animals were sacrificed 3 and 6 months after surgery. Bone neoformation was evaluated by conventional histology, radiology, and micro-CT. Model A (spheres with intersecting and aligned arrays) showed higher penetration and interconnection. Histological and radiological analysis by micro-CT revealed increased bone formation in the grafted groups, especially when combined with a membrane. Our innovative 3D printing technology, combined with precise scaffold design and efficient cleaning, shows potential for bone regeneration. However, further refinement of the technique and long-term clinical studies are crucial to establish the safety and efficacy of these advanced 3D printed scaffolds in human patients.

Bilateral carcinoma in situ of Wharton's duct after chronic obstructive sialadenitis: inflammation as the cause of malignancy?

A case of bilateral carcinoma in situ of Wharton's duct after chronic sialadenitis is reported. The patient, a 54-year-old man, complained of recurrent pain and swelling in the left lower submandibular region. Computed tomography showed large stones in the hilar area of both submandibular glands. The patient underwent bilateral submandibular excision. Histologic and immunohistochemical examination revealed squamous metaplasia with areas of carcinoma in situ in both right and left ducts adjacent to the calculus. To the best of our knowledge, this is the first case report in the literature describing an association between obstructive sialadenitis and carcinoma in situ of Wharton's duct. We discuss etiologic factors and chronic inflammation as a possible cause of malignancy.

Land suitability assessment in the catchment area of four Southwestern Atlantic coastal lagoons: multicriteria and optimization modeling.

In the present study, a land suitability assessment was conducted in the basin of four Uruguayan coastal lagoons (Southwestern Atlantic) to analyze the productive development while minimizing eutrophication, biodiversity loss and conflicts among different land uses. Suitable land for agriculture, forest, livestock ranching, tourism and conservation sectors were initially established based on a multi-attribute model developed using a geographic information system. Experts were consulted to determine the requirements for each land use sector and the incompatibilities among land use types. The current and potential conflicts among incompatible land use sectors were analyzed by overlapping land suitability maps. We subsequently applied a multi-objective model where land (pixels) with similar suitability was clustered into "land suitability groups", using a two-phase cluster analysis and the Akaike Information Criterion. Finally, a linear programming optimization procedure was applied to allocate land use sectors into land suitable groups, maximizing total suitability and minimizing interference among sectors. Results indicated that current land use overlapped by 4.7 % with suitable land of other incompatible sectors. However, the suitable land of incompatible sectors overlapped in 20.3 % of the study area, indicating a high potential for the occurrence of future conflict. The highest competition was between agriculture and conservation, followed by forest and agriculture. We explored scenarios where livestock ranching and tourism intensified, and found that interference with conservation and agriculture notably increased. This methodology allowed us to analyze current and potential land use conflicts and to contribute to the strategic planning of the study area.

Merkel cell carcinoma: our experience in this rare pathology.

Merkel cell carcinoma (MCC) was first described in 1972 by Toker, who described five cases of the so-called "trabecular carcinoma of the skin ". MCC is a rare, aggressive skin cancer that affects mainly the elderly. Sun exposed areas are mainly affected, specially the head and neck. Immunohistochemical analysis is essential to reach a correct diagnosis. According to the origin of MCC, the tumor expresses both epithelial and neuroendocrine markers. MCC has a propensity for recurrence, regional and distant metastases. Several treatment options are available, such as surgical excision or Moh's surgery, accompanied by neck dissection or radio and chemotherapy in advanced cases. The present study aims to evaluate the clinical behaviour and the evolution of five cases of this disease that were treated at our institution (reference to 1100000 inhabitants) in the last five years. It is stressed on the bad prognosis of this pathology, which presents high rates of locoregional recurrence, even though the recent advances in radio and chemotherapy.

Comparative analysis of plasma-derived albumin scaffold, alveolar osteoblasts and synthetic membrane in critical mandibular bone defects: An experimental study on rats.

Repair of bone deficiencies in the craniofacial skeleton remains a challenging clinical problem. The aim of this study was to evaluate and compare the effects of a plasma-derived albumin scaffold, alveolar osteoblasts and synthetic membrane implanted into experimental mandibular defects. Bilateral mandibular defects were created in twelve immunodeficient rats. The bone defect was filled with serum scaffold alone in left sides and scaffold combined with human alveolar osteoblast in right side defects. Implanted areas were closed directly in Group 1 (n = 6) and covered by a resorbable polyglycolic-polylactic acid membrane in Group 2 (n = 6). Bone regeneration was determined at 12 weeks as measured by and exhaustive multiplanar computed tomography analysis and histological examination. No significant differences in bone density were observed between defects transplanted with scaffold alone or scaffold seeded with osteoblasts. The use of membrane did not result in a determining factor in the grade of bone regeneration between Groups 1 and 2. Based on these results, it could be concluded that the albumin scaffold alone has osteoinductive capacity but presence of seeded ostogenic cells accelerates defect repair without being significantly influenced by covering the defect with a resorbable membrane.

Trophic assessment in South American Atlantic coastal lagoons: Linking water, sediment and diatom indicators.

Within two coastal shallow lagoons, trophic state was assessed by integrating water and sediment chemical indicators such as the TRIX and the benthic biopolymeric carbon (BPC) trophic indicator, altogether with biological environmental indicators (diatom species characterization). Spatial and temporal behavior of TRIX and BPC indices suggest that water column trophic indicators reflect rather short-term variations in water quality changes, while benthic trophic indicators rather reflect consistent long-term trends which make them useful as enduring indicators of eutrophication. Canonical Correspondence Analysis (CCA) showed that both sediment and transitional water trophic state indices increased eutrophic conditions with a decreasing salinity and increasing total nutrients. Diatom species associated with elevated eutrophic condition such as Staurosirella martyi, Staurosira breviestriata, Amphora copulata, Amphora veneta, Nitzschia sp., and Bacillaria paradoxa, showed a positive correlation with both trophic indices. We highlight the need for considering sediment eutrophication indicators towards in monitoring programmes within shallow coastal lagoons.

Three-dimensional culture of mandibular human osteoblasts on a novel albumin scaffold: growth, proliferation, and differentiation potential in vitro.

PURPOSE: Bone tissue engineering is a promising approach for bone reconstruction in oral and maxillofacial surgery. The aim of this study was to investigate the microstructure and biocompatibility of a novel albumin scaffold developed from human serum on human alveolar osteoblasts. MATERIALS AND METHODS: Samples of mandibular bone were obtained during routine oral surgery. Osteoblast cells were cultured and plated in a spongy, noncalcified protein scaffold prepared with plasmatic albumin crossed with a glutaraldehyde-type agent (study group) and in a large-particle mineralized cancellous allograft (control group). Measurement of the differentiation marker alkaline phosphatase and histologic examination were performed after 30 days of incubation. The cultures were examined for cell growth patterns and morphology by scanning electron microscopy and histomorphometry. RESULTS: Cultured osteoblasts showed comparable phenotypic profiles and expressed alkaline phosphatase in albumin scaffold. Hematoxylin-eosin staining revealed a bonelike extracellular matrix in study scaffold and mineralization of osteoblasts cultured in the albumin scaffold was confirmed by von Kossa staining. CONCLUSION: Osteoblasts were able to proliferate in vitro and synthesize a bonelike extracellular matrix and mineralized tissue. The results indicate that this novel albumin scaffold is a favorable substrate for the growth and differentiation of osteoblasts and a promising material for bone tissue engineering and repair of bone defects.

Computed tomography and computer-aided design for locating available palatal bone for grafting: two case reports.

Autologous bone graft is considered the gold standard for oral and maxillofacial rehabilitation. The purpose of these case reports is to present the palate as a donor site in the oral and maxillofacial region. A surgical technique of palatal bone grafting with computer-aided design is proposed. Computed tomography and three-dimensional study with a software program (Simplant) were used to evaluate bone quality and quantity at the palatal donor site and also provide a preoperative planning tool for placement of implants. This software was also used to determine the amount of bone needed for the implant site. A palatal marginal incision was made and a full-thickness flap was elevated from the central incisor region to the premolar region. A bone trephine was used to harvest corticocancellous palatal blocks. No swelling or hematomas were found at any donor sites. Simplant software can map the bone within a defined palatal area and provide important information about the quality and quantity of bone in the donor area.

Pathological mandibular fracture after simple molar extraction in a patient with osteogenesis imperfecta treated with alendronate.

Osteogenesis imperfecta (OI), is a heterogeneous group of inherited disorders of connective tissue characterized by bone fragility. Patients with this disease frequently suffer fractures, over 80% of the extremities due to the more intensive mechanical load. Fractures of the facial bones occur very infrequently. Several studies have proved that bisphosphonate therapy may be effective in reducing fracture risk in OI patients. We report here an unusual case of pathological mandibular fracture following simple molar extraction in an adult patient with OI type I and oral alendronic acid treatment. Extraction was atraumatical and without bone removal. Fracture was treated by internal fixation by plate osteosynthesis and additional mandibulomaxillary fixation (MMF). Bone healing after fracture treatment was completely normal and no clinical signs of osteoneocrosis were observed. To the best of our knowledge, this is an unusual complication even in this type of patients. Particular care is necessary is these patients during oral surgery, even when they have been treated and controlled.

Oroantral communications. A retrospective analysis.

OBJECTIVE: To analyze characteristics, clinical evolution and surgical techniques of oroantral communication (OAC). STUDY DESIGN: We included all patients operated at the University Central Hospital (Oviedo, Spain) between 1996 and 2007. The variables assessed were age, sex, medical history, OAC size, sinus disease, surgical technique, duration of hospitalization and post-surgical evolution. RESULTS: We analyzed 12 patients (7 men and 5 women) with an average age of 47.5 years. The most frequent cause of oroantral communication was the extraction of the first upper molar. The average size of fistula was 0.9 cm. Buccal flap repair was used in 7 patients, palatal rotation-advancement flap in 4 patients and buccal fat pad in only one patient. Suture dehiscence was observed in one patient treated with a palatal flap, but no additional surgery was required. Three OAC recurred; all of them following a buccal flap procedure. All recurrences spontaneously closed between one and four months following the procedure. CONCLUSIONS: OACs are rare complications and treatment should be individualized to avoid further complications.

Unilateral absence of submandibular gland secondary to stones. Aplasia versus early atrophy.

Major salivary gland absence is a rare disorder. The cause of congenital absence of the salivary glands has not been determined, but it may be associated with ectodermal defects of the first and second branchial arches. Isolated absence of a unilateral submandibular gland is an unusual entity with less than ten cases reported in the literature. The etiopathogenesis of isolated absence of a major salivary gland without other developmental anomalies is still unclear. The formation of a sialolith within the remaining Wharton's duct, associated with isolated aplasia (versus atrophy) of a unilateral submandibular gland has been recently reported. We describe in this work two cases of sialolithiasis within the ipsilateral remaining Wharton's duct in patients with isolated absence of a unilateral submandibular gland. In the cases reported, absence of the submandibular gland may have been the result of the complete acinar atrophy secondary to an early obstruction of Wharton's duct.

Use of cultured human epithelium for coverage: a defect of radial forearm free flap donor site.

The radial forearm free flap has been popular in many areas of reconstructive surgery. Despite the many attributes of this flap in maxillofacial reconstruction, one of the disadvantages has been the morbidity of the donor site. Allogeneic cultured epidermis has been successfully applied on large second degree burns and on chronic leg ulcers. Autologous human keratinocytes and fibroblast equivalents can be cultured in-vitro from a small skin sample in order to produce a sufficient amount of epithelial autografts to cover the large defects of third-degree burn wounds. Interestingly, transplanted cultured epidermis retains characteristics of the original donor site. We report a case of a patient who underwent skin replacement by cultured epithelial autograft after wound breakdown occurred in the forearm donor site during the early postoperative period. This method could represent an auspicious alternative to conventional grafting methods for forearm free flap reconstruction. To the best of our knowledge, skin replacement by cultured epithelial autografts in this region has not been extensively described in the literature.

Primary de novo intraosseous carcinoma: report of a new case.

Primary de novo intraosseous carcinoma of the jaws has been rarely reported. We present a new case of this unusual tumour and discuss its histopathological and clinical aspects. The subject was a 76-year-old man who was seen due to complaints of pain and the presence of gingival changes in the left mandible. A panoramic radiograph and computed tomography revealed a large mandibular radiolucency. A segmentary mandibulectomy was performed and histopathologic examination proved that the tumour was an intraosseous squamous cell carcinoma. Surgeons should appreciate the aggressiveness of this tumour, despite adequate surgical treatment.

Regeneration of mandibular osteoradionecrosis with autologous cross-linked serum albumin scaffold.

Osteoradionecrosis is one of the most severe complications of radiotherapy administered for head and neck tumors. We present the first two cases of advanced and refractory mandibular osteoradionecrosis treated by application of a novel autologous cross-linked 3D serum matrix. Patients were followed clinically and radiographically up to 24 months. Complete wound healing and intact mucosal cover were achieved in both cases. At 12 months, the radiographic values showed an almost complete regeneration of the bone defect, which continued a favourable progression increased to the maximum by 24 months after surgery. The use of an autologous serum-derived scaffold proved to be a quick, predictable, cost-effective and safe adjunct to the conservative surgical treatment of this pathology.