373 research outputs found
Regulation of transferrin receptor synthesis by human cytotrophoblast cells in culture
The aim of this study was to examine the capacity of the syncytiotrophoblast to regulate transferrin receptor (TfR) synthesis in response to modulations in maternal iron supply. The model used was the primary trophoblast cell culture. Trophoblast cells isolated from term human placentas were cultured in iron-poor (Medium 199), iron-depleted (desferrioxamine (DFO)) and iron supplemented (diferric transferrin (hTf-2Fe), ferric ammonium citrate (FAG)) medium. TfR synthesis was reduced in response to hTf-2Fe supplementation. FAC did not modulate TfR synthesis. Iron deprivation by DFO resulted in clear stimulation of TfR synthesis. These results show that the differentiating trophoblast cells respond to pertubations in the (transferrin-mediated) iron supply by adjustments in the rate of TfR synthesis. Taking syncytiotrophoblast in culture as model for the maternal/fetal interface in vivo, our results would suggest that the placenta is able to make short term adjustments of the capacity for iron uptake
The effect of target speed on perception of visual motion direction in a patient with akinetopsia
Although much research has been devoted to the neural correlates of motion perception, the processing of speed of motion is still a topic of discussion. Apart from patient LM, no in-depth clinical research has been done in the past 20 years on this topic. In the present study, we investigated patient TD, who suffered from the rare disorder akinetopsia due to bilateral lesions of V5 after stroke. By means of a Random-Dot-Kinematogram (RDK) in which speed was varied systematically, it was found that TD was impaired in perceiving the direction of movement at speeds exceeding 9 deg/s. Our study suggests that V5 plays an important role in processing high-speed visual motion and further implies that V5 does not play a crucial role in processing low-speed visual motion. A remarkable finding, which has not been shown before, was that TD always reported the opposite direction of the actual movement at a speed of 24 deg/s. This suggests a form of the continuous wagon wheel illusion, which might have been caused by intact brain areas operating at different sampling rates than area V5
Explaining the polarized macrophage pool during murine allergic lung inflammation
IntroductionDifferentially polarized macrophages, especially YM1+ and MHCII+ macrophages, play an important role in asthma development. The origin of these polarized macrophages has not been elucidated yet. We therefore aimed to investigate how proliferation, monocyte recruitment, and/or switching of polarization states contribute to this specific pool of polarized interstitial and alveolar macrophages during development of house dust mite (HDM)-induced allergic lung inflammation in mice.MethodsMale and female mice were first treated intranasally with PKH26 to label lung-resident macrophages and were then exposed to either HDM or phosphate-buffered saline (PBS) for two weeks. Different myeloid immune cell types were quantified in lung tissue and blood using flow cytometry.ResultsWe found that macrophage polarization only starts up in the second week of HDM exposures. Before this happened, unpolarized alveolar and interstitial macrophages transiently increased in HDM-exposed mice. This transient increase was mostly local proliferation of alveolar macrophages, while interstitial macrophages also contained unlabeled macrophages suggesting monocyte contribution. After two weeks of exposures, the number of interstitial and alveolar macrophages was similar between HDM and PBS-exposed mice, but the distribution of polarization states was remarkably different. HDM-exposed mice selectively developed YM1+ alveolar macrophages and MHCII-hi interstitial macrophages while nonpolarized macrophages were lost compared to PBS-exposed mice. DiscussionIn this HDM model we have shown that development of a polarized macrophage pool during allergic inflammation is first dependent on proliferation of nonpolarized tissue-resident macrophages with some help of infiltrating unlabeled cells, presumably circulating monocytes. These nonpolarized macrophages then acquire their polarized phenotype by upregulating YM1 on alveolar macrophages and MHCII on interstitial macrophages. This novel information will help us to better understand the role of macrophages in asthma and designing therapeutic strategies targeting macrophage functions.</p
Weight loss in adult male Wistar rats by Roux-en-Y gastric bypass is primarily explained by caloric intake reduction and presurgery body weight
Relative to feeding an LF diet, continued feeding an HF/S diet does not negatively impact recovery from RYGB surgery in rats. Relative to feeding an LF diet, continued feeding an HF/S diet promotes RYGB-induced weight loss. The RYGB-induced weight loss is primarily explained by reduced cumulative EI and higher preoperative body weight, leading to comparably low levels of body fat content in HF/S and LF feeding rats
Can we safely reduce the radiation dose to the heart while compromising the dose to the lungs in oesophageal cancer patients?
PURPOSE: The aim of this study was to evaluate which clinical and treatment-related factors are associated with heart and lung toxicity in oesophageal cancer patients treated with chemoradiation (CRT). The secondary objective was to analyse whether these toxicities are associated with overall survival (OS) MATERIALS AND METHODS: The study population consisted of a retrospective cohort of 216 oesophageal cancer patients treated with curative CRT. Clinical and treatment related factors were analysed for OS and new pulmonary and cardiac events by multivariable regression analyses. The effect of these toxicities on OS was assessed by Kaplan Meyer analyses. RESULTS: Multivariable analysis revealed that pulmonary toxicity was best predicted by the mean lung dose. Cardiac complications were diverse; the most frequently occurring complication was pericardial effusion. Several cardiac dose parameters correlated with this endpoint. Patients developing radiation pneumonitis had significantly worse OS than patients without radiation pneumonitis, while no difference was observed in OS between patients with and without pericardial effusion. OS was best predicted by the V45 of the lung and tumour stage. None of the cardiac dose parameters predicted OS in multivariable analyses. CONCLUSION: Cardiac dose volume parameters predicted the risk of pericardial effusion and pulmonary dose volume parameters predicted the risk of radiation pneumonitis. However, in this patient cohort, pulmonary DVH parameters (V45) were more important for OS than cardiac DVH parameters. These results suggest that reducing the cardiac dose at the expense of the dose to the lungs might not always be a good strategy in oesophageal cancer patients
Toward evidence‐based severity assessment in rat models with repeated seizures: II. Chemical post–status epilepticus model
Objective
Considering the complexity of neuronal circuits and their epilepsy‐associated alterations, epilepsy models cannot be completely replaced by in vitro experimental approaches. Decisions about ethical approval of in vivo studies require a thorough weighing of the animal's burden and the benefit regarding the expected gain in knowledge.
Methods
Based on combined behavioral, biochemical, and physiological analyses, we assessed the impact on animal well‐being and condition in different phases of the pilocarpine post–status epilepticus (SE) model in rats.
Results
As a consequence of SE, increased levels of impairment were evident in the early postinsult phase and late chronic phase, whereas only mild impairment was observed in the interim phase. Parameters that stood out as sensitive indicators of animal distress include burrowing, which proved to be affected throughout all experimental phases, saccharin preference, fecal corticosterone metabolites, heart rate, and heart rate variability.
Significance
The cumulative burden with temporary but not long‐lasting phases of more pronounced impairment suggests a classification of severe as a basis for laboratory‐specific prospective and retrospective evaluation. Among the parameters analyzed, burrowing behavior and saccharin preference stand out as candidate parameters that seem to be well suited to obtain information about animal distress in epileptogenesis models
The impact of induction and/or concurrent chemoradiotherapy on acute and late patient-reported symptoms in oropharyngeal cancer:Application of a mixed-model analysis of a prospective observational cohort registry
BACKGROUND The goal of this study was to comprehensively investigate the association of chemotherapy with trajectories of acute symptom development and late symptom recovery in patients with oropharyngeal cancer (OPC) by comparing symptom burden between induction chemotherapy followed by concurrent chemoradiotherapy (ICRT), concurrent chemo-radiotherapy (CRT), or radiotherapy (RT) alone.METHODS Among a registry of 717 patients with OPC, the 28-item patient-reported MD Anderson Symptom Inventory-Head and Neck Module (MDASI-HN) symptoms were collected prospectively at baseline, weekly during RT, and 1.5, 3 to 6, 12, and 18 to 24 months after RT. The effect of the treatment regimen (ICRT, CRT, and RT alone) was examined with mixed-model analyses for the acute and late period. In the CRT cohort, the chemotherapy agent relationship with symptoms was investigated.RESULTS Chemoradiation (ICRT/CRT) compared with RT alone resulted in significantly higher acute symptom scores in the majority of MDASI-HN symptoms (ie, 21 out of 28). No late symptom differences between treatment with or without chemotherapy were observed that were not attributable to ICRT. Nausea was lower for CRT with carboplatin than for CRT with cisplatin; cetuximab was associated with particularly higher scores for acute and late skin, mucositis, and 6 other symptoms. The addition of ICRT compared with CRT or RT alone was associated with a significant increase in numbness and shortness of breath.CONCLUSION The addition of chemotherapy to definitive RT for OPC patients was associated with significantly worse acute symptom outcomes compared with RT alone, which seems to attenuate in the late posttreatment period. Moreover, induction chemotherapy was specifically associated with worse numbness and shortness of breath during and after treatment.LAY SUMMARYChemotherapy is frequently used in addition to radiotherapy cancer treatment, yet the (added) effect on treatment-induced over time is not comprehensively investigatedThis study shows that chemotherapy adds to the symptom severity reported by patients, especially during treatment</p
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