950 resultados para Group-v


Relevância:

60.00% 60.00%

Publicador:

Resumo:

The perivascular epithelioid cell has been proposed to be the unifying proliferating cell type in a number of lesions such as angiomyolipoma, lymphangiomyomatosis, clear cell sugar tumor and renal capsuloma. With the exception of rare examples of angiomyolipoma, they are non-metastasizing. We report four examples of a new member of this family of perivascular epithelioid cell neoplasms that occur in abdominopelvic location and show metastatic properties. The patients, all women, were aged 19 to 41 years (mean, 32), and presented with a tumor mass involving the serosa of the ileum, uterus or pelvic cavity. Morphologically, the tumors were composed of sheets of large polygonal cells with glycogen-rich clear or eosinophilic cytoplasm and moderately pleomorphic nuclei, traversed by a delicate vasculature, mimicking clear cell carcinoma. There were areas of coagulative necrosis and occasional mitotic figures. Intracytoplasmic brown pigment was present in two cases. Spindly cells, smooth muscle and fat were absent. Lymphovascular invasion was present in all, lymph node metastasis was documented in two and metastasis to the ovary was present in one case. Two patients developed widespread metastatic disease after 10 and 28 months from diagnosis. One patient showed the clinical signs of tuberous sclerosis. In spite of the epithelial-like appearance, the tumor cells were negative for epithelial markers but were strongly positive with the melanogenesis-related marker HMB45. Another melanogenesis marker (MART-1) was positive in two cases. Other markers including S-100 protein, vimentin, muscle-specific actin, desmin and chromogranin A were negative. Thus, these tumors are not readily classifiable in the existing schema of known entities, and show over-lapping morpho-phenotypic features of clear cell sugar tumor of the lung and epithelioid angiomyolipoma. We consider them as sarcomas composed of a pure population of uncommitted perivascular epithelioid cell, that lack modulation toward smooth muscle or adipose cells.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Aims-To evaluate the prevalence of pseudoangiomatous hyperplasia of mammary stroma in gynaecomastia and its immunohistochemical profile in this setting.Methods-Eighty eight cases of gynaecomastia recovered from the files of the department of pathology, Botucatu School of Medicine from 1976 to 1996 were studied. In the cases associated with pseudoangiomatous hyperplasia of mammary stroma, immunoreactivity for cytokeratins (CAM 5.2), vimentin, CD34, factor VIII related antigen, and the oestrogen and progesterone receptors were studied.Results-Pseudoangiomatous hyperplasia of mammary stroma was found in 21 of 88 cases of gynaecomastia (23.8%). In all cases, the cells lining the spaces were positive for vimentin, whereas CAM 5.2 and factor VIII related antigen were consistently negative. Nineteen of the 21 cases showed immunoreactivity for CD34. Ductal epithelial cells were positive for both the oestrogen receptor and the progesterone receptor, whereas stromal cells were negative.Conclusions-Pseudoangiomatous hyperplasia of mammary stroma was present in approximately one quarter of the cases of gynaecomastia. This immunohistochemical study confirms the mesenchymal origin of the stromal cells that line the pseudovascular spaces, as has been found in female cases of pseudoangiomatous hyperplasia of mammary stroma.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Objectives To report methodology and overall clinical, laboratory and radiographic characteristics for Henoch-Schonlein purpura (HSP), childhood polyarteritis nodosa (c-PAN), c-Wegener granulomatosis (c-WG) and c-Takayasu arteritis (c-TA) classification criteria.Methods The preliminary Vienna 2005 consensus conference, which proposed preliminary criteria for paediatric vasculitides, was followed by a EULAR/PRINTO/PRES-supported validation project divided into three main steps. Step 1: retrospective/prospective web-data collection for HSP, c-PAN, c-WG and c-TA, with age at diagnosis <= 18 years. Step 2: blinded classification by consensus panel of a subgroup of 280 cases (128 difficult cases, 152 randomly selected) enabling expert diagnostic verification. Step 3: Ankara 2008 Consensus Conference and statistical evaluation (sensitivity, specificity, area under the curve, kappa-agreement) using as 'gold standard' the final consensus classification or original treating physician diagnosis.Results A total of 1183/1398 (85%) samples collected were available for analysis: 827 HSP, 150 c-PAN, 60 c-WG, 87 c-TA and 59 c-other. Prevalence, signs/symptoms, laboratory, biopsy and imaging reports were consistent with the clinical picture of the four c-vasculitides. A representative subgroup of 280 patients was blinded to the treating physician diagnosis and classified by a consensus panel, with kappa-agreement of 0.96 for HSP (95% CI 0.84 to 1), 0.88 for c-WG (95% CI 0.76 to 0.99), 0.84 for c-TA (95% CI 0.73 to 0.96) and 0.73 for c-PAN (95% CI 0.62 to 0.84), with an overall. of 0.79 (95% CI 0.73 to 0.84).Conclusion EULAR/PRINTO/PRES propose validated classification criteria for HSP, c-PAN, c-WG and c-TA, with substantial/almost perfect agreement with the final consensus classification or original treating physician diagnosis.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

The genus Xanthomonas is a diverse and economically important group of bacterial phytopathogens, belonging to the gamma-subdivision of the Proteobacteria. Xanthomonas axonopodis pv. citri (Xac) causes citrus canker, which affects most commercial citrus cultivars, resulting in significant losses worldwide. Symptoms include canker lesions, leading to abscission of fruit and leaves and general tree decline(1). Xanthomonas campestris pv. campestris (Xcc) causes black rot, which affects crucifers such as Brassica and Arabidopsis. Symptoms include marginal leaf chlorosis and darkening of vascular tissue, accompanied by extensive wilting and necrosis(2). Xanthomonas campestris pv. campestris is grown commercially to produce the exopolysaccharide xanthan gum, which is used as a viscosifying and stabilizing agent in many industries(3). Here we report and compare the complete genome sequences of Xac and Xcc. Their distinct disease phenotypes and host ranges belie a high degree of similarity at the genomic level. More than 80% of genes are shared, and gene order is conserved along most of their respective chromosomes. We identified several groups of strain-specific genes, and on the basis of these groups we propose mechanisms that may explain the differing host specificities and pathogenic processes.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

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

Relevância:

60.00% 60.00%

Publicador:

Resumo:

The maintenance of the avulsed teeth in appropriate media for preserving the cellular viability has been important for repairing the periodontal ligament and preventing the root resorption after tooth reimplantation. Propolis is a substance capable of preserving cellular viability. This study aimed to analyze the propolis substance as a storage media for maintaining the avulsed teeth, besides to determine the ideal time period for keeping the tooth inside it. Thus, 60 maxillary right central incisors of rats were extracted and divided into five groups. In groups I and II, teeth were kept in propolis for 60 min and 6 h, respectively; in group III, teeth were kept in milk for 6 h; in group IV, teeth were kept dry for 60 min; and in group V, they were immediately reimplanted. All teeth had their root canals filled with calcium hydroxide paste. Following, teeth were reimplanted in their sockets. After 15 and 60 days, animals were killed and the obtained samples were processed in laboratory for microscopic and morphometric analyzing. The results showed that the occurrence of inflammatory resorption, dental ankylosis and the formation of the connective tissue parallel to the root surface were similar among groups. It could be verified a greater occurrence of replacement resorption in group IV when comparing to other groups. In groups I and IV, the presence of periodontal ligament-like connective tissue was substantially smaller than the other groups. Regarding to the cementum amount over the root, it could be observed that this was present in smaller amount in groups I and IV. Group II was similar to groups III and IV. Therefore, according to the results of this study, the use of propolis as a storage media for maintaining avulsed teeth could be highlighted, and the 6-h period was more appropriate than the 60-min period.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Background. Periodontal disease is often associated with systemic diseases and is characterized by destruction of the tissues supporting the teeth. Patients using immunosuppressive drugs such as tacrolimus are among those who suffer from tissue destruction. Objective. We sought to evaluate the effects of laser and photodynamic therapies (PDT; nonsurgical) as an adjunct to scaling and rootplaning (SRP) in the treatment of corona-induced periodontitis in rats immunosuppressed with tacrolimus (Prograf).Materials and Methods. The animals were divided into 5 groups. Each groups had 6 rats. Group I, the control group, received only saline solution throughout the study period of 42 days and did not receive periodontal treatment; group II received saline solution and SRP; group III received tacrolimus (1 mg/kg per day) and was treated with SRP; group IV animals were treated identically to group III and then administered laser treatment; and in group V, the animals were treated identically to group III and then administered PDT.Results. Statistical analysis indicated decreased bone loss with the progression of time (P = .035). There was no difference between the bone loss associated with the types of treatment administered to groups I, II, and III (P > .9) or groups IV and V (P > .6). The analysis also indicated that immunosuppression was not a bone loss-determining factor.Conclusion. Laser and PDT therapies were effective as an adjunctive treatment to SRP in reducing bone loss caused by experimental periodontitis induced in animals being treated systemically with tacrolimus.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

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

Relevância:

60.00% 60.00%

Publicador:

Resumo:

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

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Platelet-derived growth factor-BB (PDGF-BB) stimulates repair of healing-impaired chronic wounds such as diabetic ulcers and periodontal lesions. However, limitations in predictability of tissue regeneration occur due, in part, to transient growth factor bioavailability in vivo. Here, we report that gene delivery of PDGF-B stimulates repair of oral implant extraction socket defects. Alveolar ridge defects were created in rats and were treated at the time of titanium implant installation with a collagen matrix containing an adenoviral (Ad) vector encoding PDGF-B (5.5 x 10(8) or 5.5 x 10(9) pfu ml (1)), Ad encoding luciferase (Ad-Luc; 5.5 x 10(9) pfu ml (1); control) or recombinant human PDGF-BB protein (rhPDGF-BB, 0.3 mg ml (1)). Bone repair and osseointegration were measured through backscattered scanning electron microscopy, histomorphometry, microcomputed tomography and biomechanical assessments. Furthermore, a panel of local and systemic safety assessments was performed. Results indicated that bone repair was accelerated by Ad-PDGF-B and rhPDGF-BB delivery compared with Ad-Luc, with the high dose of Ad-PDGF-B more effective than the low dose. No significant dissemination of the vector construct or alteration of systemic parameters was noted. In summary, gene delivery of Ad-PDGF-B shows regenerative and safety capabilities for bone tissue engineering and osseointegration in alveolar bone defects comparable with rhPDGF-BB protein delivery in vivo. Gene Therapy (2010) 17, 95-104; doi: 10.1038/gt.2009.117; published online 10 September 2009

Relevância:

60.00% 60.00%

Publicador:

Resumo:

1 Nitric oxide (NO) and alpha(2)-adrenoceptor and imidazoline agonists such as moxonidine may act centrally to inhibit sympathetic activity and decrease arterial pressure.2 In the present study, we investigated the effects of pretreatment with L-NAME ( NO synthesis inhibitor), injected into the 4th ventricle (4th V) or intravenously (i.v.), on the hypotension, bradycardia and vasodilatation induced by moxonidine injected into the 4th V in normotensive rats.3 Male Wistar rats with a stainless steel cannula implanted into the 4th V and anaesthetized with urethane were used. Blood flows were recorded by use of miniature pulsed Doppler flow probes implanted around the renal, superior mesenteric and low abdominal aorta.4 Moxonidine (20 nmol), injected into the 4th V, reduced the mean arterial pressure (-42+/-3 mmHg), heart rate (-22+/-7 bpm) and renal (-62+/-15%), mesenteric (-41+/-8%) and hindquarter (-50+/-8%) vascular resistances.5 Pretreatment with L-NAME (10 nmol into the 4th V) almost abolished central moxonidine-induced hypotension (-10+/-3 mmHg) and renal (-10+/-4%), mesenteric (-11+/-4%) and hindquarter (-13+/-6%) vascular resistance reduction, but did not affect the bradycardia (-18+/-8 bpm).6 the results indicate that central NO mechanisms are involved in the vasodilatation and hypotension, but not in the bradycardia, induced by central moxonidine in normotensive rats. British Journal of Pharmacology (2004).

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Migraine and temporomandibular disorders (TMD) are highly prevalent conditions that frequently coexist in the same patient. The relationship between migraine and TMD is complex. Migraineurs often have pain in the TMD area; TMD sufferers, in turn, often experience headaches in addition to the pain in the jaw. Finally, migraine and TMD are comorbid, and the final phenotype of patients with the comorbidity may represent the aggregated contribution of both. Herein we briefly discuss the clinical commonalities of migraine and TMD, and the differential diagnosis of these conditions with other causes of facial pain. We close by presenting our experience in the treatment of patients with the comorbidity.

Relevância:

60.00% 60.00%

Publicador:

Resumo:

Until recently, the study of negative and antagonistic interactions (for example, competition and predation) has dominated our understanding of community structure, maintenance and assembly(1). Nevertheless, a recent theoretical model suggests that positive interactions (for example, mutualisms) may counterbalance competition, facilitating long-term coexistence even among ecologically undifferentiated species(2). Mullerian mimics are mutualists that share the costs of predator education(3) and are therefore ideally suited for the investigation of positive and negative interactions in community dynamics. The sole empirical test of this model in a Mullerian mimetic community supports the prediction that positive interactions outweigh the negative effects of spatial overlap(4) (without quantifying resource acquisition). Understanding the role of trophic niche partitioning in facilitating the evolution and stability of Mullerian mimetic communities is now of critical importance, but has yet to be formally investigated. Here we show that resource partitioning and phylogeny determine community structure and outweigh the positive effects of Mullerian mimicry in a species-rich group of neotropical catfishes. From multiple, independent reproductively isolated allopatric communities displaying convergently evolved colour patterns, 92% consist of species that do not compete for resources. Significant differences in phylogenetically conserved traits (snout morphology and body size) were consistently linked to trait-specific resource acquisition. Thus, we report the first evidence, to our knowledge, that competition for trophic resources and phylogeny are pivotal factors in the stable evolution of Mullerian mimicry rings. More generally, our work demonstrates that competition for resources is likely to have a dominant role in the structuring of communities that are simultaneously subject to the effects of both positive and negative interactions.