2494 research outputs found
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Extinction for a discrete competition system with feedback controls
No full textAbstract
We consider a nonautonomous discrete competition system with nonlinear interinhibition terms and feedback controls. By constructing a suitable Lyapunov function, we obtain some criteria about the extinction of one of the two species and the corresponding feedback controls varieties. Our conclusions not only supplement but also improve some existing ones. Numerical simulations are used to illustrate our analytic analysis. We show that feedback control variables play an important role in the extinction property of the system
Loss of quiescence and self-renewal capacity of hematopoietic stem cell in an in vitro leukemic niche
No full textAbstract
Background
Leukemic and mesenchymal stem cells interact in the leukemic microenvironment and affect each other differently. This interplay has also important implications for the hematopoietic stem cell (HSC) biology and function. This study evaluated human HSC self-renewal potential and quiescence in an in vitro leukemic niche without leukemic cells.
Methods
A leukemic niche was established by co-culturing mesenchymal stem cells with a fresh conditioned medium obtained from a leukemic (REH) cell line. After 3\ua0days, the REH-conditioned medium was removed and freshly isolated CD34+ at a density of up to 100,000 cells/ml were added to the leukemic niche. CD34+ cell evaluations (cell cycle, self-renewal gene expression and migration capacity) were performed after 3 further days of co-culture. Additionally, we preliminary investigated the soluble factors present in the leukemic niche and their effect on the mesenchymal stem cells. Statistical significance was assessed by Student\u2019s t test or the nonparametric test Kolmogorov\u2013Smirnov.
Results
By co-culturing normal mesenchymal stem cells with the REH-conditioned medium we showed that hematopoietic stem cells, normally in a quiescent state, enter cell cycle and proliferate. This loss of quiescence was accompanied by an increased expression of Ki-67 and c-Myc, two well-known cell proliferation-associated markers. Two central regulators of quiescence GATA2 and p53 were also down regulated. Importantly, two genes involved in HSC self-renewal, Klf4 and the histone\u2013lysine N -methyltransferase enzyme Ezh2, were severely affected. On the contrary, c-Kit expression, the stem cell factor receptor, was upregulated in hematopoietic stem cells when compared to the normal niche. Interestingly, mesenchymal stem cells incubated with the REH-conditioned medium stopped growing, showed a flattened morphology with the appearance of small vacuoles, and importantly, became positive for the senescence-associated beta-galactosidase activity. Evaluation of the leukemic-conditioned medium showed increased IL-6 and IL-8, suggesting that these cytokines could be responsible for the observed changes.
Conclusions
Our results showed that quiescence and self-renewal are severely affected in this leukemic niche. This in vitro leukemic niche, established without leukemic cells, will facilitate HSC gene expression evaluation and the development of therapeutic agents aimed to neutralize soluble factors and the cell signaling pathways involved in HSC alterations
Appraising the situation: a framework for understanding compassionate care
No full textAbstract
Background
Compassion in healthcare represents an ideal way of interacting with patients. It entails an active response to suffering, distress or discomfort that can be associated with people seeking health related support or treatment. However, reports from within healthcare highlight that compassionate care (CC) is not always achieved. It may be especially problematic when trying to work with a patient who seems unwilling or unable to engage with advice provided by a healthcare professional (HCP).
Methods
We conducted a grounded theory study to understand the meaning of CC for HCPs working with patients with type 2 diabetes. Data were collected between May-October 2015 using focus groups and individual interviews; 36 HCPs took part in total. For the current paper, we used constant comparison to analyse data from transcripts where participants talked about working with a \u2018non-adherent\u2019 patient.
Results
Analysis highlighted how appraisal of their encounter with a non-adherent patient could affect whether CC was seen as possible by participants. Therefore, we used a transactional model of emotions as a framework for understanding HCPs\u2019 narratives. This involved a consideration of their primary appraisal of such encounters, which participants said often resulted in a sense of threat, failure and rejection. Their secondary appraisals, which centred on coping resources, included problem-focused approaches (e.g. supporting the patient to plan how to move forwards in managing their health) and emotion-focused approaches (e.g. recognising change was hard, appreciating it may not be the right time for the patient to change). These appraisals could be modified by: a) gaining experience as a HCP; b) altering what was seen as professional success; c) their connection with the patient; d) how much autonomy they had in their job.
Conclusions
Our findings provide new insights and emphasise that CC in response to non-adherent patients is not determined solely by a HCP\u2019s innate nature, but can be affected by an individual\u2019s appraisal of this interaction and the resources he/she has available to cope. This has implications for the environment within which staff work
Automated closed-loop resuscitation of multiple hemorrhages: a comparison between fuzzy logic and decision table controllers in a sheep model
No full textAbstract
Background
Hemorrhagic shock is the leading cause of trauma-related death in the military setting. Definitive surgical treatment of a combat casualty can be delayed and life-saving fluid resuscitation might be necessary in the field. Therefore, improved resuscitation strategies are critically needed for prolonged field and en route care. We developed an automated closed-loop control system capable of titrating fluid infusion to a target endpoint. We used the system to compare the performance of a decision table algorithm (DT) and a fuzzy logic controller (FL) to rescue and maintain the mean arterial pressure (MAP) at a target level during hemorrhages. Fuzzy logic empowered the control algorithm to emulate human expertise. We hypothesized that the FL controller would be more effective and more efficient than the DT algorithm by responding in a more rigid, structured way.
Methods
Ten conscious sheep were submitted to a hemorrhagic protocol of 25\ua0ml/kg over three separate bleeds. Automated resuscitation with lactated Ringer\u2019s was initiated 30\ua0min after the first hemorrhage started. The endpoint target was MAP. Group differences were assessed by two-tailed t test and alpha of 0.05.
Results
Both groups maintained MAP at similar levels throughout the study. However, the DT group required significantly more fluid than the FL group, 1745\ua0\ub1\ua0552\ua0ml (42\ua0\ub1\ua011\ua0ml/kg) versus 978\ua0\ub1\ua0397\ua0ml (26\ua0\ub1\ua011\ua0ml/kg), respectively ( p \ua0=\ua00.03).
Conclusion
The FL controller was more efficient than the DT algorithm and may provide a means to reduce fluid loading. Effectiveness was not different between the two strategies. Automated closed-loop resuscitation can restore and maintain blood pressure in a multi-hemorrhage model of shock
Pleurodesis with pseudomonas aeruginosa-mannose\u2013sensitive hemagglutinin for pneumothorax secondary to COPD: a retrospective study
No full textAbstract
Background
Pneumothorax is a potentially life-threatening complication of chronic obstructive pulmonary disease (COPD) that leads to cardiopulmonary compromise. According to the British Thoracic Society (BTS) guidelines, medical pleurodesis is recommended for inoperable patients suffering from COPD-related pneumothorax. Several sclerosing agents are currently in use, but none have been proven to be the best choice, as each one has effectiveness and safety issues. Recent research has shown that Pseudomonas aeruginosa-mannose\u2013sensitive hemagglutinin (PAMSHA) is a safe bioagent with low toxicity and good immune-boosting effects that can induce the aseptic inflammation necessary to cause pleural adhesion.
The aim of this study is to report our experience using PAMSHA in medical pleurodesis to treat inoperable cases of persistent pneumothorax secondary to COPD.
Methods
Records of 78 inoperable patients with persistent pneumothorax secondary to COPD treated with PAMSHA pleurodesis were retrospectively reviewed. Pleurodesis was performed by administering 1\ua0ml of PAMSHA (mixed with lidocaine and 30-40\ua0ml of normal saline) intrapleurally.
Results
The resolution of pneumothorax was observed in all of the patients treated with PAMSHA pleurodesis (success rate\u2009=\u2009100%). Some of them experienced mild chest pain and fever, but no long-term side effects were reported.
Conclusion
Our data suggest that PAMSHA pleurodesis is a safe and effective option for the treatment of persistent pneumothorax secondary to COPD
Development and evaluation of a formula for predicting introduction of medication self-management in stroke patients in the Kaifukuki rehabilitation ward
No full textAbstract
Background
Medication self-management in stroke patients is important to prevent further progression of disease and incidence of side effects. The purpose of this study was to create a formula for predicting medication self-management introduction in stroke patients using functional independence measure items and patient data, including medication-related information.
Methods
This was a retrospective analysis of 104 patients (cerebral infarction, cerebral hemorrhage, subarachnoid hemorrhage) discharged from the Kaifukuki rehabilitation ward at Showa University Fujigaoka Rehabilitation Hospital from January to December 2012. Multivariate analysis was performed to develop a formula for predicting achievement of medication self-management.
Results
Of the 104 patients, 39 (37.5%) achieved medication self-management. In the logistic regression analysis, number of drugs, age, walk/wheelchair mobility FIM, and memory FIM were extracted as significant factors independently contributing to achievement of medication self-management ( p \u2009<\u20090.05). The prediction formula was [4.404\u2009\u2212\u20090.229\u2009\ud7\u2009number of drugs at admission\u2009+\u20090.470\u2009\ud7\u2009walk/wheelchair mobility FIM at admission\u2009+\u20090.416\u2009\ud7\u2009memory FIM at admission\u2009\u2212\u20090.112\u2009\ud7\u2009age].
Conclusions
In the future, this formula may be used as an index to predict success of medication self-management in stroke patients
Higher bioavailability of magnesium citrate as compared to magnesium oxide shown by evaluation of urinary excretion and serum levels after single-dose administration in a randomized cross-over study
No full textAbstract
Background
The development of several disorders, such as cardiovascular diseases, diabetes and osteoporosis, has been linked to suboptimal dietary magnesium (Mg) intake. In this context, a number of studies have tried to investigate which Mg compounds are best suited for Mg supplementation. Results suggest that organic Mg compounds are superior to the inorganic Mg oxide in terms of bioavailability, but a reliable statement cannot yet be made due to systematic differences in the applied study designs.
Methods
This single-center, randomized, open, 2-period, 2-supplementation, 2-sequence, single-dose, cross-over study was conducted in 20 healthy male subjects of Caucasian origin to investigate and compare the bioavailability of Mg citrate, an organic Mg compound, and Mg oxide, an inorganic Mg compound. In order to reliably assess the bioavailability of both Mg compounds, subjects were supplemented with magnesium to saturate their Mg-pools before administration of each study product. The bioavailability of both Mg compounds was then assessed by measurement of the renally eliminated Mg quantity during an interval of 24\ua0h after single-dose Mg administration (A
e 0-24h
) as primary endpoint. Additionally, the Mg concentrations in a subset of leukocytes, in erythrocytes and in serum were measured on an exploratory basis.
Results
After administration, A
e 0-24h
of magnesium was higher for Mg citrate than for Mg oxide. A
e 0-24h
for both study products was compared by analysis of variance (ANOVA), revealing an adjusted mean difference of 0.565\ua0mmol, which was statistically significant at the 5% level (95% confidence interval of 0.212 to 0.918\ua0mmol, p \u2009=\u20090.0034). Besides, serum Mg concentrations were statistically significantly higher for Mg citrate than for Mg oxide at several time points after administration. No statistically significant difference was shown in intracellular Mg contents.
Conclusions
This study confirms former study results showing a higher bioavailability of the organic Mg compound Mg citrate compared to Mg oxide. It can be concluded that Mg citrate, similar to other organic Mg compounds, may be more suitable than Mg oxide to optimize the dietary magnesium intake.
Trial ..
Concurrent chemoradiotherapy combined with enteral nutrition support: a radical treatment strategy for esophageal squamous cell carcinoma patients with malignant fistulae
No full textAbstract
Background
Concurrent chemoradiotherapy (CCRT) significantly increases the survival rate of esophageal squamous cell carcinoma (ESCC) patients with malignant fistulae. Recent clinical evidence has shown the benefits of enteral nutrition for malnourished cancer patients. In this study, we aimed to validate that, with the support of enteral nutrition, ESCC patients who develop malignant fistulae might be able to complete CCRT and achieve long-term survival.
Methods
We reviewed the medical records of 652 patients with ESCC who received definitive CCRT at Sun Yat-sen University Cancer Center between January 2010 and December 2012. Treatment outcome and toxicity were retrospectively evaluated in 40 ESCC patients with malignant fistulae. All the 40 patients were treated with CCRT and evaluated by clinical nutritionists using nutrition risk screening (NRS) before, during, and after treatment. Twenty-two patients received a nasogastric tube, and 18 underwent percutaneous endoscopic gastrostomy feeding. The median energy intake was 2166 kcal/day. Treatment response was evaluated at 3\ua0months after the completion of CCRT.
Results
With a median follow-up of 18\ua0months (range, 3\u201339\ua0months), patients\u2019 1-year overall survival (OS) rate was 62.5%, and the estimated OS time was 25.5\ua0months. Univariate analysis showed that the NRS score ( P \ua0=\ua00.003), increase in NRS score ( P \ua0=\ua00.024), fistula closure ( P \ua0=\ua00.011), and response to treatment ( P \ua0<\ua00.001) were significantly associated with OS. Multivariate analysis showed that tumor response ( P \ua0=\ua00.044) and increase in NRS score ( P \ua0=\ua00.044) were independent predictors of OS. Grade 3 vomiting was observed in 8 patients (20.0%), grade 3 neutropenia was observed in 11 patients (27.5%), and grade 3 cough was observed in 13 patients (32.5%); 2 patients (5.0%) died of massive bleeding during treatment.
Conclusions
CCRT combined with enteral nutrition support is effective for ESCC patients with malignant fistulae. Patients have an increased potential to be cured, especially those who experience complete response and have an ..
Novel germline mutations in FLCN gene identified in two Chinese patients with Birt\u2013Hogg\u2013Dub\ue9 syndrome
No full textAbstract
Birt\u2013Hogg\u2013Dub\ue9 (BHD) syndrome, a hereditary renal cancer syndrome caused by mutations in the folliculin ( FLCN ) gene, is characterized by the presence of fibrofolliculomas, pulmonary cysts, spontaneous pneumothorax, and renal cell carcinoma (RCC). Few BHD syndrome cases have been reported in Asian countries, and cutaneous presentations are relatively rare in Asian patients. Asian BHD patients may be misdiagnosed due to their atypical manifestations. Here, we report two Chinese BHD patients with novel FLCN mutations (c.946-947delAG in exon 9 and c.770-772delCCT in exon 7). Both of them had RCC and spontaneous pneumothorax without fibrofolliculomas. In patients with RCC and pulmonary cysts but without cutaneous lesions, screening for mutations in the FLCN gene should be performed, especially for those with a family history of RCC or pulmonary cysts (pneumothorax)
Patient advocate perspectives on involvement in HTA: an international snapshot
No full textPlain English summary
A number of health technology assessment (HTA) organisations have developed processes to engage patients in the assessment of new health technologies such as pharmaceuticals, diagnostic tests, devices or medical procedures. Typically, this involves the HTA agency providing an opportunity for patient advocates and their patient organisations (support groups for patients with a specific disease or condition) to provide submissions detailing experiences with the disease and the health technology that is being assessed. While some literature exists about how HTA agencies view the engagement of patients in the HTA process, it is not yet clear how the patient advocates and patient organisations themselves view this engagement. To answer this question, we surveyed the views of patient advocates who were members of patient organisations known to be engaged in the process of HTA or evidence-based practice. Snowballing \u2013 that is, passing on the survey invitation from individuals invited to take part in the survey to other individuals \u2013 occurred in one of the countries. The responses in this country provided a very useful comparison between the views of people who were appointed as the \u2018patient representatives\u2019 on an HTA committee with those who contributed input as part of the general patient organisation engagement process. Our findings identify gaps in understanding of the purpose of patient involvement and whether patient organisations felt their input made a difference, the information and support provided, and if and how feedback is given to the patient organisations. Our work can help inform further research as well as continuing improvements in HTA patient engagement processes.
Abstract
Background
Patient involvement in health technology assessment (HTA) processes is becoming more frequent. However, it is not clear how patient advocates and their disease-based patient organisations that are involved in HTA view their involvement. We report on the results of an international survey of patient advocates and members of patient organisations about their experiences and perceptions of that involvement.
Methods
A 16-question survey was sent out to patient advocates and members of patient groups known to be involved in HTA processes or evidence-based practice. The survey consisted of open-ended questions focusing on respondent characteristics, stage and nature of involvement, support from HTA agencies for involvement, purpose of involvement, feedback on involvement, and whether the respondents felt that their input made a difference.
Results ..