Mycobacterium marinum infection: a case report

The infection by Mycobacterium marinum in humans is relatively uncommon. When it occurs, it mainly affects the skin, usually with a chronic, indolent and benign evolution. The diagnosis requires a high index of suspicion, and a significant delay may be observed between the first symptoms to the final diagnosis. This present case reports a M. marinum infection in an immunocompetent patient that had a chronic undiagnosed injury on the dominant hand for at least five years. The patient had several medical consultations, without proper suspicion, hampering adequate diagnostic investigation. Histopathology detected tuberculoid granulomas, but showed no acid-fast bacilli. The culture in appropriate medium and the polymerase chain reaction-restriction enzyme analysis (PRA)-hsp65 confirmed the diagnosis. Treatment with clarithromycin (1 g/day) for three months was effective. Although uncommon, this infection is a contact zoonosis. Therefore, it is important for clinicians to be aware of this diagnosis and properly guide preventable measures to professionals that are in risk group.

Expression of cellular components in granulomatous inflammatory response in piaractus mesopotamicus model

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Healing process of dogs' pulpless teeth after apicoectomy and root canal filling at different levels

Dogs' teeth with infected root canals, were submitted to apicoectomy and the root canals were filled flush or 2 mm short. In a third group the canals were left unfilled and only the access openings were closed. One hundred and eighty days after the treatment, the animals were killed and the specimens prepared for histological analysis. Repair was not observed in the teeth with unfilled root canals. The healing observed in the teeth with root canals filled flush was less complete than the healing observed when the root canals were filled 2 mm short.

Histopathology of the pulp of primary molars with active and arrested dentinal caries

The purpose of this study was to compare the histological appearance of the pulp of human primary molars with active and arrested lesions. The sample consisted of 36 primary molars (18 with active lesions and 18 with arrested lesions) extracted from 35 children between 5 to 9 years of age. The histological diagnosis was classified in normal pulp, transitional stage, partial pulpitis, total pulpitis and total necrosis, and then subdivided in three subgroups: treatable, untreatable and questionable. Results showed that normal pulp or transitional stage (treatable category) was diagnosed in 50% of teeth with arrested lesions, compared to 11.1% of teeth with active lesions. Partial pulpitis (questionable category) was present in 38.8% with arrested lesions compared to 22.2% with active lesions. Total pulpitis and total necrosis (untreatable category) was diagnosed in 11.2% with arrested lesions compared to 66.7% with active lesions. The observed frequencies of histological categories between both groups were statistically significant (P < 0.05). Histologically, pulp reaction under active and arrested lesions in primary molars revealed the formation of a basophilic calcio-traumatic line at the junction of the primary and reparative dentin, formation of reparative dentin and a regular odontoblastic layer in 60% of the cases. Results indicated that the type of lesion (active or arrested) is a good indicator of the histological status of the pulp.

Biological compatibility of some types of endodontic calcium hydroxide and glass ionomer cements

The purpose of this work was to evaluate the biological compatibility of the Sealapex, Apexit, Sealer 26 and Ketac Endo endodontic cements. Polyethylene tubes containing these cements were implanted in the subcutaneous tissue of 40 (forty) rats. The animals were sacrificed after 14 and 90 days. A descriptive analysis of the reactions found in the connective tissue by contact with the cements was performed. The magnitude of inflammatory infiltrate, the presence and predominance of cell types and their distribution as to the filling material and reparative phenomena, such as fibroblastic and angioblastic proliferation and formation of fibrous capsules, were subjectively measured. After 90 days, all cements presented statistically significant reduction of the inflammatory reaction, presence of a fibrous tissue capsule in contact with the opening of the tubes containing the filling materials, and reduction of fibroblastic proliferation. Angioblastic proliferation decreased only for the Sealer 26 and Ketac Endo groups. All cements tested were either partially or totally phagocyted, and the mildest inflammatory response was found for the Sealer 26 group at both evaluation periods.

Peripheral cemento-ossifying fibroma in child. A follow-up of 4 years. Report of a case

Peripheral cement-ossifying fibroma is a relatively common gingival growth of a reactive rather than neoplastic nature, whose pathogenesis is uncertain. It predominantly affects adolescents and young adults, with peak prevalence between 10 and 19 years. We report here the clinical case of a 5-year-old girl with disease duration of 3 years, who was followed up for 4 years, showing a gingival health and normal radiopacity of bone.

Clopidogrel enhances mesenchymal stem cell proliferation following periodontitis

Bone formation is dependent on the differentiation of osteoblasts from mesenchymal stem cells (MSCs). In addition to serving as progenitors, MSCs reduce inflammation and produce factors that stimulate tissue formation. Upon injury, MSCs migrate to the periodontium, where they contribute to regeneration. We examined the effect of clopidogrel and aspirin on MSCs following induction of periodontitis in rats by placement of ligatures. We showed that after the removal of ligatures, which induces resolution of periodontal inflammation, clopidogrel had a significant effect on reducing the inflammatory infiltrate. It also increased the number of osteoblasts and MSCs. Mechanistically, the latter was linked to increased proliferation of MSCs in vivo and in vitro. When given prior to inducing periodontitis, clopidogrel had little effect on MSC or osteoblasts numbers. Applying aspirin before or after induction of periodontitis did not have a significant effect on the parameters measured. These results suggest that clopidogrel may have a positive effect on MSCs in conditions where a reparative process has been initiated.

Odontoma em pacientes odontopediátrico: diagnóstico e tratamento. Relato de caso clínico.

Odontoma is a term that refers to a benign tumor of odontogenic and mixed nature, composed of epithelial and mesenchymal components. Histologically, they are compounds of different configurations including dental enamel, dentin, cementum and in some cases the pulp tissue. A slow growing asymptomatic tumor, odontoma is usually discovered through routine radiographic examination. A 3-year old male patient sought care at the School of Dentistry’s Baby Clinic (UNESP-Araçatuba), complaining of “small ball close to the teeth.” During the interview, the mother reported that the lesion was observed soon after a trauma, and evolved in less than one month. An ulcerated lesion with a 0.8 cm diameter was found during intraoral clinical examination. It was located in the inferior and anterior region of the mouth, between teeth 81 and 82, and there was also crown distalization. A radiographic examination showed a radiolucent area and root distance. In the absence of clinical and radiographic characteristics suggesting a case of odontoma, the differential diagnosis was peripheral giant cell lesion and pyogenic granuloma. So the area was punctured. Nonetheless, due to the absence of liquid, the surgical removal of the lesion was performed, followed by histological examination, which showed the definite diagnosis of a suggestive case of emerging odontoma.

Cisto ósseo simples: relatos de casos

Usually diagnosed in routine radiographs, the simple bone cyst occurs infrequently. Etiology is unknown and differential diagnosis has to be made with dentigerous cyst, keratocystic odontogenic tumor, adenomatoid odontogenic tumor, ameloblastoma and central giant cell granuloma. Treatment is surgical, by perforating the cortical bone. In most cases an empty cavity, without any capsule or epithelial covering, is encountered, but it may have a liquid content. Perforation of the mandibular cortical bone elicits a response that results in bone repair of the empty cavity. This article reviews the subject and presents two cases of this entity and discusses the possible factors that could interfere in healing course.

Lesion Development in White-tailed Deer (Odocoileus virginianus) Experimentally Infected with Mycobacterium bovis

The recent discovery of tuberculosis in free-living white-tailed deer in northeastern Michigan underscores the need for increased understanding of the pathogenesis of tuberculosis in wildlife species. To investigate lesion development in white-tailed deer, 32 deer were experimentally infected by intratonsilar instillation of 300 colony-forming units of Mycobacterium bovis. Three deer each were euthanatized and examined at days 15, 28, 42, and 56 after inoculation, and five deer each were euthanatized and examined at days 89, 180, 262, and 328 after inoculation. Microscopic lesions first were seen in the medial retropharyngeal lymph node and lung 28 and 42 days after inoculation, respectively. Lung lesions were present in 12 (38%) of 32 deer, involving 23 lung lobes. Left caudal and right middle and caudal lobes were involved in 17 (74%) of the 23 affected lung lobes. Lesions in the medial retropharyngeal lymph node first appeared as granulomas composed of aggregates of macrophages and Langhans-type giant cells. Some early granulomas contained centrally located neutrophils. As granulomas developed, neutrophils were replaced with a central zone of caseous necrosis that first showed signs of mineralization 42 days after inoculation. Granulomas increased in size as the zone of caseous necrosis expanded. Peripheral fibrosis, first seen at 56 days after inoculation, progressed to only a thin fibrous capsule by 328 days after inoculation. By the termination of the study, the central necrotic core of the granuloma contained abundant liquefied necrotic material and grossly resembled an abscess. Although tuberculous lesions in white-tailed deer follow a developmental pattern similar to that in cattle, fibrosis is less pronounced and the advanced lesions may liquefy, a change seldom reported in cattle. An understanding of lesion development will aid in the identification of the spectrum of disease that may be seen in this important wildlife reservoir of tuberculosis.

Pro-inflammatory effects of the aqueous extract of Echinometra lucunter sea urchin spines

The sea urchin, Echinometra lucunter, can be found along the Western Central Atlantic shores. In Brazil, it is responsible by circa 50% of the accidents caused by marine animals. The symptoms usually surpass trauma and may be pathologically varied and last differently, ranging from spontaneous healing in a few days, to painful consequences lasting for weeks. In this work, we have mimicked the sea urchin accident by administering an aqueous extract of the spine into mice and rats and evaluated the pathophysiological developments. Our data clearly indicate that the sea urchin accident is indeed a pro-inflammatory event, triggered by toxins present in the spine that can cause edema and alteration in the leukocyte-endothelial interaction. Moreover, the spine extract was shown to exhibit a hyperalgesic effect. The extract is rich in proteins, as observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, but also contains other molecules that can be analyzed by reversed phase high-performance liquid chromatography. Altogether, these effects corroborate that an E. lucunter encounter is an accident and not an incident, as frequently reported by the victims.

Histomorphometric analysis of inflammatory response and necrosis in re-implanted central incisor of rats treated with low-level laser therapy

Low-level laser therapy is a tool employed in the management of post-operative inflammation process and in the enhancement of reparative process. The aim of the study was to perform histological evaluation of dental and periodontal ligament of rats central upper-left incisor teeth re-implanted and irradiated with low-level laser (InGaAl, 685 nm, 50 J/cm(2)) 15, 30, and 60 days after re-implantation. Seventy-two male rats had the central upper left incisor removed and kept for 15 min on dry gauze before replantation. Laser was irradiated over the root surface and empty alveolus prior replantation and over surrounding mucosa after the re-implantation. After histological procedures, all slices were analyzed regarding external resorption area and histological aspects. We observed an increase of root resorption (p < 0.05) in the control group compared to the laser group at 15, 30, and 60 days. These results showed that the laser groups developed less root resorption areas than the control group in all experimental periods. Additionally, histological analysis revealed less inflammatory cells and necrotic areas in laser groups.

The contribution of a murine CNS-TB model for the understanding of the host-pathogen interactions in the formation of granulomas

Central nervous system (CNS) tuberculosis (TB) is the most severe form of TB, characterized morphologically by brain granulomas and tuberculous meningitis (TBM). Experimental strategies for the study of the host-pathogen interaction through the analysis of granulomas and its intrinsic molecular mechanisms could provide new insights into the neuropathology of TB. To verify whether cerebellar mycobacterial infection induces the main features of the disease in human CNS and better understand the physiological mechanisms underlying the disease, we injected bacillus Calmette-Guerin (BCG) into the mouse cerebellum. BCG-induced CNS-TB is characterized by the formation of granulomas and TBM, a build up of bacterial loads in these lesions, and microglial recruitment into the lesion sites. In addition, there is an enhanced expression of signaling molecules such as nuclear factor-kappa B (NF-kappa B) and there is a presence of inducible nitric oxide synthase (iNOS) in the lesions and surrounding areas. This murine model of cerebellar CNS-TB was characterized by cellular and biochemical immune responses typically found in the human disease. This model could expand our knowledge about granulomas in TB infection of the cerebellum, and help characterize the physiological mechanisms involved with the progression of this serious illness that is responsible for killing millions people every year. (C) 2012 Elsevier B.V. All rights reserved.

Treatment of central giant cell lesions using bisphosphonates with intralesional corticosteroid injections

Central giant cell lesions are benign intraosseous proliferative lesions that have considerable local aggressiveness. Nonsurgical treatment methods, such as intralesional corticosteroid injections, systemic calcitonin and interferon have been reported. Recently, bisphosphonates have been used to treat central giant cell lesions. A case of a 36-year-old male with a central giant cell lesion crossing the mandibular midline was treated with intralesional corticosteroids combined with alendronate sodium for the control of systemic bone resorption. The steroid injections and the use of bisphosphonates were stopped after seven months when further needle penetration into the lesion was not possible due to new bone formation. After two years, the bony architecture was near normal, and only minimal radiolucency was present around the root apices of the involved teeth. The patient was followed up for four years, and panoramic radiography showed areas of new bone formation. Thus far, neither recurrence nor side effects of the medication have been detected.

Treatment of severe forms of paracoccidioidomycosis: is there a role for corticosteroids?

Despite their immunosuppressive effects, corticosteroids have long been used as adjunct therapy (aCST) in the treatment of infectious diseases. The rationale is that in certain infections it is necessary to decrease the exacerbated host's inflammatory response, which can otherwise result in tissue damage and organ dysfunction. In fact, a major concern in treating paracoccidioidomycosis (PCM) is the host's intense inflammatory response to Paracoccidioides brasiliensis, which can be further intensified by antifungal therapy. Depending on its localization, this immunological phenomenon may be life threatening or result in permanent sequels, as is the case for some patients with cerebral or laryngeal involvement. However, the literature on aCST in paracoccidioidomycosis treatment is scarce and as a result we present our recent experience in the management of four patients with severe PCM manifestations, i.e., cerebral paracoccidioidal granuloma, laryngeal stenosis, compressive abdominal mass, and exacerbated inflammatory response with tissue destruction. In addition to the antifungal therapy, these patients required aCST, which probably promoted their clinical improvement and/or prevented serious complications. We suggest that aCST: (a) can potentially help in the management of selected cases of severe forms of PCM, particularly when there is a risk of acute complications, and (b) that it can be used safely provided that the risk-benefit ratio is carefully weighed. Well-controlled, prospective studies of aCST in the treatment of severe cases of paracoccidioidomycosis are needed to better define its role in the management of PCM.