27 research outputs found
A case of crescentic glomerulonephritis associated with relapsing polychondritis
Relapsing polychondritis (RP) is a rare autoimmune disease, characterized by recurrent inflammatory episodes affecting various carttilageus structures. Renal involvement in RP is unusual. Our case was a 42-year old woman presented with nephretic syndrome. Diagnosis of RP was made because of recurrent chondritis of both auricles, chondritis of costovertebral joints, non-erosive inflammatory arthritis of knees, and inflammation of ocular structures. Renal biopsy findings revealed diffuse crescentic and sclerotic glomerulonephritis, pauciimmune type. The diagnosis of RP may be missed when the destructive cartilage feature is not apparent or rare presentation of disease such as ocular or renal involvement preceded other manifestations. In this case we found that the irregular prednisolone use may prevent destructive cartilage damage but not renal failure of patient. We concluded that the association of crescentic glomerulonephritis in a patient with RP was assumed to be a rare manifestation of this disease. © 2019 The Author(s)
Gaps in Information Access in Social Networks
The study of influence maximization in social networks has largely ignored
disparate effects these algorithms might have on the individuals contained in
the social network. Individuals may place a high value on receiving
information, e.g. job openings or advertisements for loans. While
well-connected individuals at the center of the network are likely to receive
the information that is being distributed through the network, poorly connected
individuals are systematically less likely to receive the information,
producing a gap in access to the information between individuals. In this work,
we study how best to spread information in a social network while minimizing
this access gap. We propose to use the maximin social welfare function as an
objective function, where we maximize the minimum probability of receiving the
information under an intervention. We prove that in this setting this welfare
function constrains the access gap whereas maximizing the expected number of
nodes reached does not. We also investigate the difficulties of using the
maximin, and present hardness results and analysis for standard greedy
strategies. Finally, we investigate practical ways of optimizing for the
maximin, and give empirical evidence that a simple greedy-based strategy works
well in practice.Comment: Accepted at The Web Conference 201
Reducing Access Disparities in Networks using Edge Augmentation
In social networks, a node's position is a form of \it{social capital}.
Better-positioned members not only benefit from (faster) access to diverse
information, but innately have more potential influence on information spread.
Structural biases often arise from network formation, and can lead to
significant disparities in information access based on position. Further,
processes such as link recommendation can exacerbate this inequality by relying
on network structure to augment connectivity.
We argue that one can understand and quantify this social capital through the
lens of information flow in the network. We consider the setting where all
nodes may be sources of distinct information, and a node's (dis)advantage deems
its ability to access all information available on the network. We introduce
three new measures of advantage (broadcast, influence, and control), which are
quantified in terms of position in the network using \it{access signatures} --
vectors that represent a node's ability to share information. We then consider
the problem of improving equity by making interventions to increase the access
of the least-advantaged nodes. We argue that edge augmentation is most
appropriate for mitigating bias in the network structure, and frame a budgeted
intervention problem for maximizing minimum pairwise access.
Finally, we propose heuristic strategies for selecting edge augmentations and
empirically evaluate their performance on a corpus of real-world social
networks. We demonstrate that a small number of interventions significantly
increase the broadcast measure of access for the least-advantaged nodes (over 5
times more than random), and also improve the minimum influence. Additional
analysis shows that these interventions can also dramatically shrink the gap in
advantage between nodes (over \%82) and reduce disparities between their access
signatures
Information access representations and social capital in networks
Social network position confers power and social capital. In the setting of
online social networks that have massive reach, creating mathematical
representations of social capital is an important step towards understanding
how network position can differentially confer advantage to different groups
and how network position can itself be a source of advantage. In this paper, we
use well established models for information flow on networks as a base to
propose a formal descriptor of the network position of a node as represented by
its information access. Combining these descriptors allows a full
representation of social capital across the network. Using real-world networks,
we demonstrate that this representation allows the identification of
differences between groups based on network specific measures of inequality of
access
The effect of low level laser on condylar growth during mandibular advancement in rabbits
<p>Abstract</p> <p>Introduction</p> <p>It has been shown that Low Level Laser (LLL) has a positive effect on bone formation. The aim of this study was to evaluate the effect of low level laser on condylar growth during mandibular advancement in rabbits.</p> <p>Materials and methods</p> <p>Continuous forward mandibular advancement was performed in fourteen male Albino rabbits with the mean age of 8 weeks and the mean weight of 1.5 ± 0.5 kg, with acrylic inclined planes. The rabbits were randomly assigned into two groups after 4 weeks. LLL (KLO3: wave length 630 nm) was irradiated at 3 points around the TMJ, through the skin in the first group. The exposure was performed for 3 minutes at each point (a total of 9 minutes) once a day for 3 weeks. The control group was not exposed to any irradiation. The rabbits in both groups were sacrificed after two months and the histological evaluation of TMJ was performed to compare fibrous tissue, cartilage, and new bone formation in condylar region in both groups. Disc displacement was also detected in both groups. Student's t-test, Exact Fisher and Chi square tests were used for the statistical analysis.</p> <p>Results</p> <p>The formation of fibrous tissue was significantly lower, while bone formation was significantly greater in lased group as compared with control group. The thickness of cartilage did not differ significantly between two groups.</p> <p>Conclusion</p> <p>Irradiation of LLL (KLO3) during mandibular advancement in rabbits, increases bone formation in condylar region, while neither increase in the cartilage thickness nor fibrous tissues was observed.</p
Effects of low power laser irradiation on bone healing in animals: a meta-analysis
<p>Abstract</p> <p>Purpose</p> <p>The meta-analysis was performed to identify animal research defining the effects of low power laser irradiation on biomechanical indicators of bone regeneration and the impact of dosage.</p> <p>Methods</p> <p>We searched five electronic databases (MEDLINE, EMBASE, PubMed, CINAHL, and Cochrane Database of Randomised Clinical Trials) for studies in the area of laser and bone healing published from 1966 to October 2008. Included studies had to investigate fracture healing in any animal model, using any type of low power laser irradiation, and use at least one quantitative biomechanical measures of bone strength. There were 880 abstracts related to the laser irradiation and bone issues (healing, surgery and assessment). Five studies met our inclusion criteria and were critically appraised by two raters independently using a structured tool designed for rating the quality of animal research studies. After full text review, two articles were deemed ineligible for meta-analysis because of the type of injury method and biomechanical variables used, leaving three studies for meta-analysis. Maximum bone tolerance force before the point of fracture during the biomechanical test, 4 weeks after bone deficiency was our main biomechanical bone properties for the Meta analysis.</p> <p>Results</p> <p>Studies indicate that low power laser irradiation can enhance biomechanical properties of bone during fracture healing in animal models. Maximum bone tolerance was statistically improved following low level laser irradiation (average random effect size 0.726, 95% CI 0.08 - 1.37, p 0.028). While conclusions are limited by the low number of studies, there is concordance across limited evidence that laser improves the strength of bone tissue during the healing process in animal models.</p
Low-intensity continuous ultrasound triggers effective bisphosphonate anticancer activity in breast cancer
Ultrasound (US) is a non-ionizing pressure wave that can produce mechanical and thermal effects. Bisphosphonates have demonstrated clinical utility in bone metastases treatment. Preclinical studies suggest that bisphosphonates have anticancer activity. However, bisphosphonates exhibit a high affinity for bone mineral, which reduces their bioavailability for tumor cells. Ultrasound has been shown to be effective for drug delivery but in interaction with gas bubbles or encapsulated drugs. We examined the effects of a clinically relevant dose of bisphosphonate zoledronate (ZOL) in combination with US. In a bone metastasis model, mice treated with ZOL+US had osteolytic lesions that were 58% smaller than those of ZOL-treated animals as well as a reduced skeletal tumor burden. In a model of primary tumors, ZOL+US treatment reduced by 42% the tumor volume, compared with ZOL-treated animals. Using a fluorescent bisphosphonate, we demonstrated that US forced the release of bisphosphonate from the bone surface, enabling a continuous impregnation of the bone marrow. Additionally, US forced the penetration of ZOL within tumors, as demonstrated by the intratumoral accumulation of unprenylated Rap1A, a surrogate marker of ZOL antitumor activity. Our findings made US a promising modality to trigger bisphosphonate anticancer activity in bone metastases and in primary tumors
Crohn’s Disease with Oral Onset - A Case Report
Background: Crohn’s disease is an inflammatory bowel disease that can affect any part of the gastrointestinal (GI) tract including the mouth. Bowel symptoms are predominant. Oral involvement may precede the GI symptoms. This case report presents a patient affected by Crohn’s disease with oral onset.
Case presentation: We present a 30-year-old pregnant woman complaining of chronic, multiple, yellow-white crusted ulcers predominantly involving the lips. In addition, there were small painless lesions on the palate, buccal and labial attached gingivae, alveolar mucosa and vestibule. The lesions were present since 3 months ago. The patient had not previously experienced any oral lesions or systemic diseases. The laboratory tests were normal. Laboratory investigation showed increase in neutrophil and eosinophil count. Incisional biopsy of the buccal mucosal lesions was performed. In histopathological examination, acanthotic and parakeratotic epithelium with intraepithelial clefts was observed. Inflammatory cells such as eosinophil and polymorphonuclear (PMN) leukocytes were profoundly present in the clefts and diffusely in the epithelium. Blood vessels, collagen fibers and in-depth muscle and fat tissues were also observed. Based on these characteristics, the diagnosis of pyostomatitis vegetans was made. Considering the biopsy results and the presence of GI symptoms such as abdominal pain and diarrhea after postpartum, Crohn’s disease was suspected and therefore, the patient was referred to a gastroenterologist for definitive diagnosis and treatment. The patient showed the diagnostic signs of Crohn’s disease.
Conclusion: This report emphasizes the important role of oral lesions as the first sign in the diagnosis of systemic diseases
Effect of low power Helium-Neon Laser radiation on healing of minor bone deformation of rabbits Tibia
History and Objectives: Due to discrepancies on the effect of low power Helium-Neon laser on healing of bone fracture, the present study intends to investigate such effect on healing of bone deformation of rabbit tibia.
Materials and Methods: An experimental study on 39 albino rabbits was carried out. They were randomly divided into control and experimental groups. Under aseptic condition and using anesthesia, an incision was made on skin with deep fascia on the internal surface of tibia bone on the left side of the animal. With an electric drill (2mm), a small deformation or hole was created on this surface. The day of surgery was considered as zero day and animals were divided into 3 groups of 14, 21 and 28 days. A low power laser, 1.2 J/cm², was applied daily once every day. Animals were killed and the left tibia bone was removed. Biomechanic studies were performed on the bones. The degree of fragility was determined by using 3 point bending of the bones. The absorbed energy at the point of fracture and the extent of bone deformation and elastic stability was measured.
Results: The extent of elastic stability and absorbed energy was significant in 21st and 28th day of experimental group respectively (P<0.05). Augmentation of biomechanic specificities was observed in the 3 experimental groups and differences were significant for day 14-28 and 21-28.
Conclusion: Laser radiation with low power Helium-Neon with energy density of 1.2 J/cm² is performed according to the procedure in the present study increases the speed of bone healing at the site of tibia bone deformation