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21.

Purpose

Despite great advances in medical image segmentation, the accurate and automatic segmentation of endoscopic scenes remains a challenging problem. Two important aspects have to be considered in segmenting an endoscopic scene: (1) noise and clutter due to light reflection and smoke from cutting tissue, and (2) structure occlusion (e.g. vessels occluded by fat, or endophytic tumours occluded by healthy kidney tissue).

Methods

In this paper, we propose a variational technique to augment a surgeon’s endoscopic view by segmenting visible as well as occluded structures in the intraoperative endoscopic view. Our method estimates the 3D pose and deformation of anatomical structures segmented from 3D preoperative data in order to align to and segment corresponding structures in 2D intraoperative endoscopic views. Our preoperative to intraoperative alignment is driven by, first, spatio-temporal, signal processing based vessel pulsation cues and, second, machine learning based analysis of colour and textural visual cues. To our knowledge, this is the first work that utilizes vascular pulsation cues for guiding preoperative to intraoperative registration. In addition, we incorporate a tissue-specific (i.e. heterogeneous) physically based deformation model into our framework to cope with the non-rigid deformation of structures that occurs during the intervention.

Results

We validated the utility of our technique on fifteen challenging clinical cases with 45 % improvements in accuracy compared to the state-of-the-art method.

Conclusions

A new technique for localizing both visible and occluded structures in an endoscopic view was proposed and tested. This method leverages both preoperative data, as a source of patient-specific prior knowledge, as well as vasculature pulsation and endoscopic visual cues in order to accurately segment the highly noisy and cluttered environment of an endoscopic video. Our results on in vivo clinical cases of partial nephrectomy illustrate the potential of the proposed framework for augmented reality applications in minimally invasive surgeries.
  相似文献   
22.
Muslims abstain from eating, drinking and smoking from dawn to sunset during the holy month of Ramadan. Prolonged fasting is thought to be among risk factors for many diseases, e.g., cardiovascular, gastrointestinal and various infectious diseases. It could also play a part in several eye diseases, including dry eye syndrome, glaucoma, and cataract. Toxic and oxidative effects due to increased concentrations of some biochemicals as a result of reduction in tear volume thought to play an important role in damaging ocular tissue. Human tear is an important biological fluid similar to blood in many aspects. Tear film is composed of three basic layers i.e. lipid, aqueous and mucin. The tear film covering the ocular surface presents a mechanical and antimicrobial barrier, and endures an optical refractive surface. The aim of this study was to analyze and compare tear protein of volunteers during fasting. Using two reliable analytical methods, i.e. electrophoresis and high performance liquid chromatography (HPLC), we compared tear protein content of sixty volunteers (35 males and 25 females, 23-27 years old) during fasting in holly month of Ramadan (FAST: n = 62) and one month before Ramadan (CTRL: n = 60). The results showed that some identified tear proteins decreased during fasting. On the other hand, the activity of some enzymes such as lysozyme, lactoferrin and alpha amylase also decreased in fasting samples. Electrophoresis results showed that tear protein patterns in FAST (P < 0.05) were different from those of CTRL. There were a few more protein peaks in the FAST group (P < 0.005) than in CTRL.  相似文献   
23.

Ethnopharmacological relevance

According to the Chinese, European, Iranian and Indian traditional medicines, oleo gum resin of Ferula assa-foetida (asafoetida) has therapeutic effects on different kinds of diseases. Some of these effects are related to the diseases of nervous system such as hysteresis and convulsion. In recent studies, some anti-epileptic and neuroprotective roles were also considered for it and we examined its possible role on treatment of peripheral neuropathy.

Material and methods

in vitro studies were carried out to identify the response of isolated sciatic nerves to different concentrations of oleo gum resin of asafoetida solved in Lock?s solution. Then, in vivo studies were conducted to evaluate its effect on amelioration of peripheral neuropathy in mice. Peripheral neuropathy was induced by intraperiotoneal injection of high doses of pyridoxine in adult Balb/c male mice. Tail flick tests were performed to identify the incidence of neuropathy in animals. After 10 days treatment with asafoetida, the efficiency of treatment was assessed by behavioral, electrophysiological and histological studies.

Results

in vitro experiments confirmed that incubating the nerves in aqueous extract of oleo gum rein of asafoetida increased the amplitude and decreased the latent period of nerve compound action potential (CAP). Nerve conduction velocity (NCV) and amplitude of CAP also improved in asafoetida treated animals. Histological and behavioral studies showed that asafoetida was able to facilitate the healing process in peripheral nerves.

Conclusions

in vitro experiments showed that asafoetida is a nerve stimulant and its administration in neuropathic mice exerted neuroprotecting effects through stimulating axonal regeneration and remyelination and decrement of lymphocyte infiltration.  相似文献   
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Background: Prevention, early diagnosis and reduction of mortality caused by breast cancer are the priorities ofthe world health systems. The aim of this study was to identify the social factors that affect the women’s breast healthbehavior based on the social determinants model of the World Health Organization (WHO). Materials and Method:This qualitative study was conducted and analyzed using content analysis approach. The data were collected from32 participants by semi-structured interviews and focused group discussion. The participants comprised of breastsurgeons, radiologists, health care providers and women over 35 years of age in Tehran who were selected throughpurposeful sampling. The interviews continued until data saturation was reached. Results: Based on the experiences ofthe participants, three themes were obtained from the data that shaped the women’s breast health behavior, including1) the context of health policy, 2) socioeconomic status, and 3) cultural, psychological, and behavioral factors.Conclusion: A better understanding of social determinants related to breast health behavior can be effective in designingand applying of appropriate theories and models of education and intervention, so that, by early diagnosis of breastcancer and timely treatment of patients, the disease complications and mortality would be reduced.  相似文献   
27.
MicroRNAs (miRNAs) play a key role in cancer progression by coordinately repressing target genes involved in cell proliferation, migration, and invasion. miRNAs regulate gene expression by repressing translation or directing sequence-specific degradation of complementary mRNA. Here, we report that expression of miR-1280 is significantly suppressed in human melanoma specimens when compared with nevi, and in human melanoma cell lines when compared with cultured normal human melanocytes. The proto-oncogene Src was identified as a target of miR-1280 action. Levels of Src expression were significantly higher in melanoma samples and cell lines than in nevi and normal melanocytes. miR-1280 overexpression significantly suppressed the luciferase activity of reporter plasmids containing the full-length 3′ untranslated region of Src. miR-1280-mediated suppression of Src led to substantial decreases in melanoma cell proliferation, cell cycle progression, invasion, as well as induced melanoma cell apoptosis. The effects of miR-1280 overexpression on melanoma cell proliferation and growth were reversed by Src overexpression. Intratumoral delivery of miR-1280 significantly suppressed melanoma cell growth in vivo. Our results demonstrate a novel role for miR-1280 as a tumor suppressor in melanoma, identify the Src signaling pathway as a target of miR-1280 action, and suggest a potential therapeutic role for miR-1280 in melanoma.  相似文献   
28.
Background: In this study, we tried to evaluate whether the ethyl acetate (EtOAc) extract of Teucrium polium, with a high antioxidant activity, is able to prevent the incidence of nonalcoholic steatohepatitis. Methods: Nonalcoholic steatohepatitis was induced in male N‐Mary rats using a methionine/choline‐deficient (MCD) diet. Rats were given normal diet (A), normal diet+EtOAc extract (B), MCD diet (C) and MCD diet+EtOAc (D). Results: The MCD diet led to grade 1 liver steatosis, inflammation and ballooning degeneration. In group D, these factors abated to grade 0 in 80% of the rats. In groups receiving the EtOAc extract, lipoprotein profiles had significantly improved relative to those not receiving the extract. Also, a dramatic reduction was observed in the sera alkaline phosphatase, aspartate aminotransferase and alanine aminoteransferase activities. The activities of the liver superoxide dismutase, glutathione peroxidase and glutathione reductase enzymes were also enhanced. Conclusion: The EtOAc extract could reverse the adverse effects of the MCD diet.  相似文献   
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Background/aim Frailty is associated with an increased risk of negative short-term and long-term hospital outcomes. This study aimed to evaluate the role of frailty in predicting readmission, length of stay, and quality of life in the hospitalized older adults.Materials and methods This observational study was conducted at Ziaiyan Hospital, Tehran, Iran. In total, 304 participants (65–85 years), were enrolled through the inclusion criteria from August to December 2019. The frailty index (FI) was assessed by the minimum data set-home care. Readmission was obtained through telephone interviews. The length of stay was gathered by the patient’s hospital records, and the EuroQol questionnaire was used for assessing the quality of life. Data were collected by a researcher nurse at the admission time, 30, 60, and 90 days after discharge. The logistic regression model and repeated measures ANOVA were employed to analyze the association between frailty and outcomes.ResultsAccording to FI, 102 (33.55%) participants were pre-frail, whereas 35 (11.51%) were frail. In the fully-adjusted model for readmission, the pre-frail participants had a higher risk of readmission at the hospital in comparison with the nonfrail and frail groups (OR = 1.88, 95% CI = 1.90–3.26), and also for GP visits, frail patients showed nearly significant differences (OR = 2.45, 95% CI = 0.99–6.06) but there were no differences between frail and pre-frail patients in readmissions in the emergency ward. In a fully-adjusted prolonged stay model, pre-frail patients had a higher probability to stay longer in hospital (OR = 2.28, 95% CI: 1.24–4.18). The fully-adjusted model for QoL showed, frail patients were more prone to the declined levels of QoL in comparison with pre-frail patients (OR = 10.77, 95% CI: 3.97–29.18).ConclusionsThe findings indicated that frailty worsened negative outcomes and declined QoL. Early diagnosis in hospital settings could be beneficial for designing optimal care plans for the frail and pre-frail patients.  相似文献   
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