960 resultados para giant snail
Resumo:
To evaluate the incidence and characteristics of musculoskeletal manifestations in polymyalgia rheumatica (PMR) and temporal arteritis (TA). METHODS The records of 163 cases of PMR or TA diagnosed over a 15 year period in one area of Spain were reviewed for the presence and type of musculoskeletal manifestations. RESULTS Of 163 patients, 90 had isolated PMR and 73 had TA. Eighteen of the 90 patients (20%) with isolated PMR developed distal peripheral arthritis either at diagnosis or during the course of the disease. When it occurred, synovitis was mild, monoarticular or pauci-articular, asymmetrical, transient, and not destructive. Other distal manifestations observed in these patients were carpal tunnel syndrome and distal extremity swelling with pitting oedema. In all cases these manifestations occurred in conjunction with active PMR. As expected, PMR was the most frequent musculoskeletal manifestation in patients with TA, occurring in 56% of cases. On the contrary, only 11% of patients with TA developed peripheral arthritis. An important finding was that peripheral arthritis in these patients appears to be linked only temporally to the presence of simultaneous PMR and is not observed in its absence. Distal extremity swelling or defined polyarthritis were not observed. CONCLUSION The spectrum of distal musculoskeletal manifestations of PMR in our series is similar to that reported in other populations. By contrast, distal musculoskeletal symptoms are uncommon in TA. The almost complete absence of distal musculoskeletal manifestations in patients with pure TA suggests different mechanisms of disease in PMR and TA, supporting the view of two separate conditions or one common disease in which host susceptibility influences the clinical expression.
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Introduction: Pigmented villonodular synovitis (PVNS) is a rare benign tumour of the synovium, most commonly arising around the knee. Resection remains the treatment of choice. The diffuse variant of the disease is prone to local recurrence (30-50%). However distant dissemination is extremely rare. We report the case of a patient with massive loco-regional and late distant spread to the lungs of PVNS originating in the knee. Case report: A 69 yo women presented to our service 27 years ago with PVNS in her knee. Despite multible surgical resections, synoviorthesis and external beam radiotherapy, no local control was achieved. The disease spread in all thigh compartments. Due to the resistance to all convetional treatment modalities, isolated limb perfusion with TNFα and Melphalan was performed, without any effect on local control. After the disease was diagnosed in iliac lymph nodes, the patient was subjected to a systemic chemotherapy protocol with imitamib, which had to be abandoned, due to intolerance. Due to a giant lymphoedema of the entire limb, making up for a considerable part of the patient's body weight and in view of significant skin invasion, a hip disarticulation was performed. Finally, rapidly growing lung metastases appeared on CT scan, confirmed by core-needle biopsy. Palliative chemotherapy was initiated. Interestingly, histological analysis of the disease throughout the years remained consistent with classic benign PVNS. No sarcomatous dedifferentiation was observed, not even in the pulmonary lesions. Conclusion: PVNS is a benign tumour, with a high risk of local recurrence. Malignant behaviour, with loco-regional and distant metastases remains extremely rare. A histologically benign appearance does not exclude a clinically malignant behaviour with systemic spread.
Resumo:
BACKGROUND: Management of ischemic stroke in the presence of aneurysmal brain disease is controversial. Recent retrospective evidence suggests that in selected patients, intravenous thrombolysis (IVT) remains a safe approach for reperfusion. METHODS: We document a case of post-thrombolysis aneurysmal rupture. Supported by additional scientific literature we postulate that acute aneurysmal thrombosis leading to stroke in the culprit artery may be an ominous sign of rupture and should be considered separately from fortuitously discovered distant aneurysmal disease. RESULTS: A 71-year-old female presented with an acute right middle cerebral artery stroke syndrome. IVT allowed vessel reperfusion and revealed a previously concealed, juxtaposed non-giant M1 segment saccular aneurysm. Secondary aneurysmal rupture ensued. The aneurysm was secured by surgical clipping. Postoperative course was uneventful. CONCLUSIONS: This case shows that despite reports of thrombolysis safety in the presence of brain aneurysms, thrombolysis remains potentially hazardous and hints toward an increased risk when the stroke arises on the parent vessel itself.
Resumo:
We explore the ability of the recently established quasilocal density functional theory for describing the isoscalar giant monopole resonance. Within this theory we use the scaling approach and perform constrained calculations for obtaining the cubic and inverse energy weighted moments (sum rules) of the RPA strength. The meaning of the sum rule approach in this case is discussed. Numerical calculations are carried out using Gogny forces and an excellent agreement is found with HF+RPA results previously reported in literature. The nuclear matter compression modulus predicted in our model lies in the range 210230 MeV which agrees with earlier findings. The information provided by the sum rule approach in the case of nuclei near the neutron drip line is also discussed.
Resumo:
A 3-year-old girl had a tumor growing for a month on the superior right eyelid, attached on the free margin of the eyelid and partially necrotic. A surgical excision was performed under general anesthesia. The histopathological study found an inflammatory lesion with epithelioid and giant cells, evidence of a granuloma, suggesting the diagnosis of chalazion. This case shows the various clinical presentations of this common and benign disease of the eyelid.
Resumo:
We have developed a differential scanning calorimeter capable of working under applied magnetic fields of up to 5 T. The calorimeter is highly sensitive and operates over the temperature range 10¿300 K. It is shown that, after a proper calibration, the system enables determination of the latent heat and entropy changes in first-order solid¿solid phase transitions. The system is particularly useful for investigating materials that exhibit the giant magnetocaloric effect arising from a magnetostructural phase transition. Data for Gd5(Si0.1Ge0.9)4 are presented.
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Peptide toxins synthesized by venomous animals have been extensively studied in the last decades. To be useful to the scientific community, this knowledge has been stored, annotated and made easy to retrieve by several databases. The aim of this article is to present what type of information users can access from each database. ArachnoServer and ConoServer focus on spider toxins and cone snail toxins, respectively. UniProtKB, a generalist protein knowledgebase, has an animal toxin-dedicated annotation program that includes toxins from all venomous animals. Finally, the ATDB metadatabase compiles data and annotations from other databases and provides toxin ontology.
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Nonalcoholic fatty liver disease (NAFLD) clusters in families, but the only known common genetic variants influencing risk are near PNPLA3. We sought to identify additional genetic variants influencing NAFLD using genome-wide association (GWA) analysis of computed tomography (CT) measured hepatic steatosis, a non-invasive measure of NAFLD, in large population based samples. Using variance components methods, we show that CT hepatic steatosis is heritable (∼26%-27%) in family-based Amish, Family Heart, and Framingham Heart Studies (n = 880 to 3,070). By carrying out a fixed-effects meta-analysis of genome-wide association (GWA) results between CT hepatic steatosis and ∼2.4 million imputed or genotyped SNPs in 7,176 individuals from the Old Order Amish, Age, Gene/Environment Susceptibility-Reykjavik study (AGES), Family Heart, and Framingham Heart Studies, we identify variants associated at genome-wide significant levels (p<5×10(-8)) in or near PNPLA3, NCAN, and PPP1R3B. We genotype these and 42 other top CT hepatic steatosis-associated SNPs in 592 subjects with biopsy-proven NAFLD from the NASH Clinical Research Network (NASH CRN). In comparisons with 1,405 healthy controls from the Myocardial Genetics Consortium (MIGen), we observe significant associations with histologic NAFLD at variants in or near NCAN, GCKR, LYPLAL1, and PNPLA3, but not PPP1R3B. Variants at these five loci exhibit distinct patterns of association with serum lipids, as well as glycemic and anthropometric traits. We identify common genetic variants influencing CT-assessed steatosis and risk of NAFLD. Hepatic steatosis associated variants are not uniformly associated with NASH/fibrosis or result in abnormalities in serum lipids or glycemic and anthropometric traits, suggesting genetic heterogeneity in the pathways influencing these traits.
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We develop a theoretical approach to percolation in random clustered networks. We find that, although clustering in scale-free networks can strongly affect some percolation properties, such as the size and the resilience of the giant connected component, it cannot restore a finite percolation threshold. In turn, this implies the absence of an epidemic threshold in this class of networks, thus extending this result to a wide variety of real scale-free networks which shows a high level of transitivity. Our findings are in good agreement with numerical simulations.
Resumo:
We develop a general theory for percolation in directed random networks with arbitrary two-point correlations and bidirectional edgesthat is, edges pointing in both directions simultaneously. These two ingredients alter the previously known scenario and open new views and perspectives on percolation phenomena. Equations for the percolation threshold and the sizes of the giant components are derived in the most general case. We also present simulation results for a particular example of uncorrelated network with bidirectional edges confirming the theoretical predictions.
Resumo:
The percolation properties of clustered networks are analyzed in detail. In the case of weak clustering, we present an analytical approach that allows us to find the critical threshold and the size of the giant component. Numerical simulations confirm the accuracy of our results. In more general terms, we show that weak clustering hinders the onset of the giant component whereas strong clustering favors its appearance. This is a direct consequence of the differences in the k-core structure of the networks, which are found to be totally different depending on the level of clustering. An empirical analysis of a real social network confirms our predictions.
Resumo:
We have developed a differential scanning calorimeter capable of working under applied magnetic fields of up to 5 T. The calorimeter is highly sensitive and operates over the temperature range 10¿300 K. It is shown that, after a proper calibration, the system enables determination of the latent heat and entropy changes in first-order solid¿solid phase transitions. The system is particularly useful for investigating materials that exhibit the giant magnetocaloric effect arising from a magnetostructural phase transition. Data for Gd5(Si0.1Ge0.9)4 are presented.
Resumo:
Background: The degree of metal binding specificity in metalloproteins such as metallothioneins (MTs) can be crucial for their functional accuracy. Unlike most other animal species, pulmonate molluscs possess homometallic MT isoforms loaded with Cu+ or Cd2+. They have, so far, been obtained as native metal-MT complexes from snail tissues, where they are involved in the metabolism of the metal ion species bound to the respective isoform. However, it has not as yet been discerned if their specific metal occupation is the result of a rigid control of metal availability, or isoform expression programming in the hosting tissues or of structural differences of the respective peptides determining the coordinative options for the different metal ions. In this study, the Roman snail (Helix pomatia) Cu-loaded and Cd-loaded isoforms (HpCuMT and HpCdMT) were used as model molecules in order t o elucidate the biochemical and evolutionary mechanisms permitting pulmonate MTs to achieve specificity for their cognate metal ion. Results: HpCuMT and HpCdMT were recombinantly synthesized in the presence of Cd2+, Zn2+ or Cu2+ and corresponding metal complexes analysed by electrospray mass spectrometry and circular dichroism (CD) and ultra violet-visible (UV-Vis) spectrophotometry. Both MT isoforms were only able to form unique, homometallic and stable complexes (Cd6-HpCdMT and Cu12-HpCuMT) with their cognate metal ions. Yeast complementation assays demonstrated that the two isoforms assumed metal-specific functions, in agreement with their binding preferences, in heterologous eukaryotic environments. In the snail organism, the functional metal specificity of HpCdMT and HpCuMT was contributed by metal-specific transcription programming and cell-specific expression. Sequence elucidation and phylogenetic analysis of MT isoforms from a number of snail species revealed that they possess an unspecific and two metal-specific MT isoforms, whose metal specificity was achieved exclusively by evolutionary modulation of non-cysteine amino acid positions. Conclusion: The Roman snail HpCdMT and HpCuMT isoforms can thus be regarded as prototypes of isoform families that evolved genuine metal-specificity within pulmonate molluscs. Diversification into these isoforms may have been initiated by gene duplication, followed by speciation and selection towards opposite needs for protecting copper-dominated metabolic pathways from nonessential cadmium. The mechanisms enabling these proteins to be metal-specific could also be relevant for other metalloproteins.