Progress toward an ambulatory pump-lung

ObjectivesCurrently available therapies for acute and chronic lung diseases have not been effective and have various problems associated with the technologies used. We present a novel active mixing pump-lung with the goal of providing total respiratory support to ambulatory patients.MethodsThe pump-lung is based on the concept of active mixing oxygenation within a constrained vortex. The rotation of hollow-fiber membranes disrupts the concentration boundary layer, increasing gas exchange efficiency, and simultaneously pumps the blood. Consequently, the amount of membranes required to achieve gas transfer sufficient for total respiratory support is considerably small. A series of studies, including computational design, experimental bench testing, and in vivo animal experiments, have been performed to implement this concept into a viable artificial pump-lung device.ResultsA series of pump-lung prototypes with a membrane surface area of 0.17 to 0.5 m2 were designed and characterized in vitro with bovine blood, demonstrating extremely high gas exchange efficiency. The prototype with a gas exchange surface area of 0.5 m2 was evaluated in calves. The device provided oxygen transfer of approximately 115 mL/min for respiratory support of an animal for up to 5 days.ConclusionsProgress to date suggests a high likelihood of success for an extracorporeal shorter-term lung that can be switched in and out like dialysis devices. Our device is unique in that it incorporates an integrated pumping and active mixing principle for excellent gas transfer and eliminates the need of the native right ventricle’s ability to power blood through the artificial and natural lungs

Community participation in bureaucratic organizations: Principles and strategies

The present paper points out that there are tasks that primary groups perform better than bureaucracies and those that bureaucracies perform better than primary groups. Both types of tasks are very interdependent so that sometimes primary group tasks must be performed within the boundaries of the bureaucratic organization. The argument is made that when primary groups intervene in bureaucracies, they can do so directly in non-expert tasks without lowering the effectiveness of the bureaucratic organization. When they intervene in expert aspects, they should do so indirectly through an expert advocate. However, in all intervention the primary group must take into account that its structure is contradictory to that of the bureaucracy and, therefore, it must keep as much distance as possible—consistent with its ability to intervene. From this analysis we derive a series of hypotheses suggesting when the community might ideally use the bureaucracy's own experts, when the community must hire its own experts, when the community should use mass media, strikes, indigenous workers, etc. It is suggested that the multitudinous possibilities for linkages can all be derived from a few basic underlying dimensions of the situation. Cet article montre qu'il existe certaines tâches que les groupes primaires accomplissent mieux que les bureaucraties, et certaines autres qu'accomplissent mieux les bureaucraties. Les deux sortes de tâches sont interdépendentes; donc parfois les tâches des groupes primaires doivent s'accomplir parmi les organisations bureaucratiques. Les auteurs soutiennent que les groupes primaires peuvent intervenir dans les bureaucraties en complétant les tâches non-expertes sans réduire l'efficacité de l'organisation bureaucratique. Quands ils participent à certains sujets experts, ils devraient se munir d'un agent expert. Mais dans toute intervention le groupe primaire doit se rendre compte que sa structure contredit celle de la bureaucratie et que, par conséquent, il doit se tenir autant à distance que possible par rapport à sa compétence d'intervention. De cette analyse proviennent des hypothèses qui indiquent quand une communauté peut se servir le mieux du personnel expert d'une bureaucratie, quand la communauté doit engager des experts, quand la communauté doit se servir des mass média, des grèves, des ouvriers indigènes, etc. Les nombreuses possibilités de liaisons proviennent toutes de quelques dimensions fondamentales de la situation.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42934/1/10780_2005_Article_BF02214879.pd

Attrition and bias in the MRC cognitive function and ageing study: an epidemiological investigation

BACKGROUND: Any hypothesis in longitudinal studies may be affected by attrition and poor response rates. The MRC Cognitive Function and Ageing study (MRC CFAS) is a population based longitudinal study in five centres with identical methodology in England and Wales each recruiting approximately 2,500 individuals. This paper aims to identify potential biases in the two-year follow-up interviews. METHODS: Initial non-response: Those not in the baseline interviews were compared in terms of mortality to those who were in the baseline interviews at the time of the second wave interviews (1993–1996). Longitudinal attrition: Logistic regression analysis was used to examine baseline differences between individuals who took part in the two-year longitudinal wave compared with those who did not. RESULTS: Initial non-response: Individuals who moved away after sampling but before baseline interview were 1.8 times more likely to die by two years (95% Confidence interval(CI) 1.3–2.4) compared to respondents, after adjusting for age. The refusers had a slightly higher, but similar mortality pattern to responders (Odds ratio 1.2, 95%CI 1.1–1.4). Longitudinal attrition: Predictors for drop out due to death were being older, male, having impaired activities of daily living, poor self-perceived health, poor cognitive ability and smoking. Similarly individuals who refused were more likely to have poor cognitive ability, but had less years of full-time education and were more often living in their own home though less likely to be living alone. There was a higher refusal rate in the rural centres. Individuals who moved away or were uncontactable were more likely to be single, smokers, demented or depressed and were less likely to have moved if in warden-controlled accommodation at baseline. CONCLUSIONS: Longitudinal estimation of factors mentioned above could be biased, particularly cognitive ability and estimates of movements from own home to residential homes. However, these differences could also affect other investigations, particularly the estimates of incidence and longitudinal effects of health and psychiatric diseases, where the factors shown here to be associated with attrition are risk factors for the diseases. All longitudinal studies should investigate attrition and this may help with aspects of design and with the analysis of specific hypotheses

Nucleophilic Functionalization of the Calix[6]arene Para- and Meta-Position via p‑Bromodienone Route

It is here demonstrated that the p-bromodienone route, previously reported for calix[4]arenes, is also effective for the functionalization of the calix[6]arene macrocycle. Thus, alcoholic O-nucleophiles can be introduced at the calix[6]arene exo rim. In addition, the reaction of a calix[6]arene p-bromodienone derivative with an actived aromatic substrate, such as resorcinol, led to the first example of a meta-functionalized, inherently chiral calix[6]arene derivativ

The Emergence of Hospital Federations: An Integration of Perspectives from Organizational Theory

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68464/2/10.1177_107755878704400206.pd

Parental health limitations, caregiving and loneliness among women with widowed parents: longitudinal eveidence from France

We investigate how daughters’ feelings of loneliness are impacted when widowed parents develop health limitations, and when daughters take on personal care tasks in response. Using longitudinal data from daughters of widowed parents drawn from the French Family and Intergenerational Relationships Study (ERFI, 1485 observations nested in 557 daughters), we assess (a) whether health limitations of widowed parents are associated with daughters’ feelings of loneliness regardless of whether or not daughters provide personal care and (b) whether there is an effect of care provision on loneliness that cannot be explained by parental health limitations. Fixed effect regression analyses show that widowed parents’ health limitations were associated with raised feelings of loneliness among their daughters. No significant additional effect of providing personal care to a widowed parent was found. Prior research on the impact of health limitations of older parents on the lives of their adult–children has focused mostly on issues related to informal caregiving. Our findings suggest that more attention to the psychosocial impact of parental health limitations—net of actual caregiving—on adult children’s lives is warranted

Prevalence of diabetes complications in people with type 2 diabetes mellitus and its association with baseline characteristics in the multinational A1chieve study

BACKGROUND: Current International Diabetes Federation guidelines recommend a target HbA(1c) <7.0%, but many people with diabetes worldwide find this difficult to achieve, increasing their risk of developing complications. This publication examines the prevalence of diabetes complications and its association with baseline characteristics in people with type 2 diabetes who participated in the A(1)chieve study. METHODS: A(1)chieve was a 24-week, multinational, open-label, observational study of 66,726 people with type 2 diabetes who had begun using biphasic insulin aspart 30, insulin aspart, or insulin detemir in routine clinical care. Participants were enrolled from 28 countries across four continents (Asia, Africa, Europe and South America). Baseline measurements of disease characteristics included: glycated haemoglobin (HbA(1c)), fasting (FPG) and post-prandial plasma glucose (PPG), high- and low-density lipoprotein cholesterol (H- or LDL-C), systolic blood pressure (SBP), and body mass index (BMI). Data on complications and use of vascular disease preventative drugs were collected. RESULTS: Complication rates were high (27.2% had macrovascular complications and 53.5% had microvascular complications), particularly in Russia, and use of vascular disease preventative drugs was lower than expected. Age, BMI, diabetes duration, LDL-C, and SBP were positively associated, and HDL-C negatively associated, with macro- and microvascular complications (all p < 0.05). HbA(1c) and FPG were negatively associated with macrovascular complications (both p < 0.05), which may be linked to the cross-sectional study design. CONCLUSIONS: These results suggest a worldwide failure to achieve glycaemic targets. Better diabetes management with earlier initiation and optimisation of insulin regimens (e.g., with insulin analogues in the A(1)chieve population) may reduce the prevalence of vascular complications, improve the lives of people with diabetes and reduce the burden on healthcare systems