79 research outputs found
Diurnal Variation in Urodynamics of Rat
In humans, the storage and voiding functions of the urinary bladder have a characteristic diurnal variation, with increased voiding during the day and urine storage during the night. However, in animal models, the daily functional differences in urodynamics have not been well-studied. The goal of this study was to identify key urodynamic parameters that vary between day and night. Rats were chronically instrumented with an intravesical catheter, and bladder pressure, voided volumes, and micturition frequency were measured by continuous filling cystometry during the light (inactive) or dark (active) phases of the circadian cycle. Cage activity was recorded by video during the experiment. We hypothesized that nocturnal rats entrained to a standard 12:12 light:dark cycle would show greater ambulatory activity and more frequent, smaller volume micturitions in the dark compared to the light. Rats studied during the light phase had a bladder capacity of 1.44±0.21 mL and voided every 8.2±1.2 min. Ambulatory activity was lower in the light phase, and rats slept during the recording period, awakening only to urinate. In contrast, rats studied during the dark were more active, had a lower bladder capacities (0.65±0.18 mL), and urinated more often (every 3.7±0.9 min). Average bladder pressures were not significantly different between the light and dark (13.40±2.49 and 12.19±2.85 mmHg, respectively). These results identify a day-night difference in bladder capacity and micturition frequency in chronically-instrumented nocturnal rodents that is phase-locked to the normal circadian locomotor activity rhythm of the animal. Furthermore, since it has generally been assumed that the daily hormonal regulation of renal function is a major driver of the circadian rhythm in urination, and few studies have addressed the involvement of the lower urinary tract, these results establish the bladder itself as a target for circadian regulation
Logistics of community smallpox control through contact tracing and ring vaccination: a stochastic network model
BACKGROUND: Previous smallpox ring vaccination models based on contact tracing over a network suggest that ring vaccination would be effective, but have not explicitly included response logistics and limited numbers of vaccinators. METHODS: We developed a continuous-time stochastic simulation of smallpox transmission, including network structure, post-exposure vaccination, vaccination of contacts of contacts, limited response capacity, heterogeneity in symptoms and infectiousness, vaccination prior to the discontinuation of routine vaccination, more rapid diagnosis due to public awareness, surveillance of asymptomatic contacts, and isolation of cases. RESULTS: We found that even in cases of very rapidly spreading smallpox, ring vaccination (when coupled with surveillance) is sufficient in most cases to eliminate smallpox quickly, assuming that 95% of household contacts are traced, 80% of workplace or social contacts are traced, and no casual contacts are traced, and that in most cases the ability to trace 1–5 individuals per day per index case is sufficient. If smallpox is assumed to be transmitted very quickly to contacts, it may at times escape containment by ring vaccination, but could be controlled in these circumstances by mass vaccination. CONCLUSIONS: Small introductions of smallpox are likely to be easily contained by ring vaccination, provided contact tracing is feasible. Uncertainties in the nature of bioterrorist smallpox (infectiousness, vaccine efficacy) support continued planning for ring vaccination as well as mass vaccination. If initiated, ring vaccination should be conducted without delays in vaccination, should include contacts of contacts (whenever there is sufficient capacity) and should be accompanied by increased public awareness and surveillance
Lung function in school-aged congenital diaphragmatic hernia patients; a longitudinal evaluation
Objective: Children with congenital diaphragmatic hernia (CDH) are at risk for pulmonary morbidity. Data on longitudinal evaluation of lung function in CDH are scarce. We hypothesized that CDH patients would have impaired lung function that worsens over time. We evaluated lung function and its determinants at ages 8 and 12 years. Methods: Dynamic and static lung volumes, and diffusion capacity were measured. Extracorporeal membrane oxygenation (ECMO) treatment, the standardized European neonatal treatment protocol, patch repair, duration of ventilation, type of initial mechanical ventilation, and nitric oxide treatment were entered as covariates in linear mixed models with standard deviation score (SDS) lung function parameters (FEV1, FEF 25-75, and K CO) as dependent variables. Results: Seventy-six children (27 ECMO-treated) born between 1999 and 2009 performed 113 reliable lung function tests. Severity of airflow obstruction deteriorated significantly from age 8 to 12 years: estimated mean difference (95% confidence interval [CI]) SDS FEV1 was −0.57 (−0.79 to −0.36) and SDS FEF25-75 was −0.63 (−0.89 to −0.37), both P <.001. Static lung volumes were within normal range and unchanged over time: estimated mean difference (95% CI) SDS TLC −0.27 (−0.58 to 0.04); P =.085. SDS KCO was below normal at 8 and 12 years and remained stable: −0.06 (−0.22 to 0.35); P =.648. These observations were irrespective of ECMO treatment. FEV1 and FEF25-75 were negatively associated with duration of ventilation (P <.001). Baseline data were not related with TLC or KCO. Conclusions: CDH patients should be followed into adulthood as they are at risk for worsening airflow obstruction and decreased diffusion capacity at school age, irrespective of ECMO treatment
The impact of societal cultural values and individual social beliefs on the perceived effectiveness of managerial influence strategies: a meso approach
This paper reports the findings of a 12-nation study designed to test empirically the relationships between societal cultural values, individual social beliefs, and the perceived effectiveness of different influence strategies. The relationships between three types of broad influence strategy (persuasive, assertive, and relationship based) and four dimensions of individual beliefs (cynicism, fate control, reward for application, and religiosity) were examined. Three of Project GLOBE's cultural values (in-group collectivism, uncertainty avoidance, and future orientation) were selected to investigate their direct effects on the rated effectiveness of influence strategies, and their possible interaction with dimensions of individual beliefs. Results showed that different dimensions of individual social beliefs predict the perceived effectiveness of the three types of influence strategy, and that cultural values can moderate the strength of the relationship between these dimensions of individual social beliefs and the perceived effectiveness of influence strategies
In Vitro Influence of Mycophenolic Acid on Selected Parameters of Stimulated Peripheral Canine Lymphocytes.
Mycophenolic acid (MPA) is an active metabolite of mycophenolate mofetil, a new immunosuppressive drug effective in the treatment of canine autoimmune diseases. The impact of MPA on immunity is ambiguous and its influence on the canine immune system is unknown. The aim of the study was to determine markers of changes in stimulated peripheral canine lymphocytes after treatment with MPA in vitro. Twenty nine healthy dogs were studied. Phenotypic and functional analysis of lymphocytes was performed on peripheral blood mononuclear cells cultured with mitogens and different MPA concentrations- 1 μM (10(-3) mol/m(3)), 10 μM or 100 μM. Apoptotic cells were detected by Annexin V and 7-aminoactinomycin D (7-AAD). The expression of antigens (CD3, CD4, CD8, CD21, CD25, forkhead box P3 [FoxP3] and proliferating cell nuclear antigen [PCNA]) was assessed with monoclonal antibodies. The proliferation indices were analyzed in carboxyfluorescein diacetate succinimidyl ester (CFSE)-labeled cells. All analyses were performed using flow cytometry. The influence of MPA on apoptosis was dependent on the mechanism of cell activation and MPA concentration. MPA caused a decrease in the expression of lymphocyte surface antigens, CD3, CD8 and CD25. Its impact on the expression of CD4 and CD21 was negligible. Its negative influence on the expression of FoxP3 was dependent on cell stimulation. MPA inhibited lymphocyte proliferation. In conclusion, MPA inhibited the activity of stimulated canine lymphocytes by blocking lymphocyte activation and proliferation. The influence of MPA on the development of immune tolerance-expansion of Treg cells and lymphocyte apoptosis-was ambiguous and was dependent on the mechanism of cellular activation. The concentration that MPA reaches in the blood may lead to inhibition of the functions of the canine immune system. The applied panel of markers can be used for evaluation of the effects of immunosuppressive compounds in the dog
A systematic review of analytical methods used to study subgroups in (individual patient data) meta-analyses.
OBJECTIVES: To determine whether individual patient data meta-analyses (IPDMA) are used to perform subgroup analyses and to study whether the analytical methods regarding subgroup analyses differ between IPDMA and conventional meta-analyses (CMA). STUDY DESIGN AND SETTING: IPDMA were identified with a comprehensive literature search, subsequently, CMA on similar research questions were traced. Methods for studying subgroups were compared for IPDMA and CMA that were matched with respect to domain, type of treatment, and outcome measure. RESULTS: Of all 171 identified IPDMA and 102 CMA, 80% and 45% presented subgroup analyses, respectively. For 35 IPDMA and 37 "matched" CMA, subgroup analytic methods could be compared. The number of performed subgroup analyses did not differ between IPDMA and CMA. Both IPDMA and CMA often do not report adequate information on methods of analyses. Interaction tests were often not performed in IPDMA (69%) and individual patient data was often not directly modelled (74%). CONCLUSION: Many IPDMA performed subgroup analyses, but overall treatment effects were more emphasized than subgroup effects. To study subgroups, a wide variety of analytical methods was used in both IPDMA and CMA. In general, the use and reporting of appropriate methods for subgroup analyses should be promoted. Recommendations for improvement of methods of analyses are provided
Co-ingestion of a protein hydrolysate and amino acid mixture with carbohydrate improves plasma glucose disposal in patients with type 2 diabetes.
BACKGROUND: Although insulin secretion after carbohydrate ingestion is severely impaired in patients with type 2 diabetes, amino acid and protein co-ingestion can substantially increase plasma insulin responses. OBJECTIVE: We investigated insulin responses and the subsequent plasma glucose disposal rates after the ingestion of carbohydrate alone (CHO) or with a protein hydrolysate and amino acid mixture (CHO+PRO) in patients with a long-term diagnosis of type 2 diabetes. DESIGN: Ten type 2 diabetic patients [mean (+/-SEM) age: 62 +/- 2 y; body mass index (kg/m(2)): 27 +/- 1] and 9 healthy control subjects (age: 58 +/- 1 y; body mass index: 27 +/- 1) participated in 2 trials in which the plasma insulin response was measured after the ingestion of 0.7 g carbohydrate . kg(-1) . h(-1) with or without 0.35 g . kg(-1) . h(-1) of a mixture that contained a protein hydrolysate, leucine, and phenylalanine. Continuous infusions with [6,6-(2)H(2)]glucose were then given to investigate plasma glucose disposal. RESULTS: Plasma insulin responses were higher by 299 +/- 64% and 132 +/- 63% in the CHO+PRO trial than in the CHO trial in the diabetic patients and the matched control subjects, respectively (P < 0.001). The subsequent plasma glucose responses were reduced by 28 +/- 6% and 33 +/- 3% in the CHO+PRO trial than in the CHO trial in the diabetic patients and the matched control subjects, respectively (P < 0.001). The reduced plasma glucose response in the diabetic patients was attributed to a 13 +/- 3% increase in glucose disposal (P < 0.01). CONCLUSIONS: The combined ingestion of carbohydrate with a protein hydrolysate and amino acid mixture significantly increases de novo insulin production in patients with a long-term diagnosis of type 2 diabetes. The increased insulin response stimulates plasma glucose disposal and reduces postprandial glucose concentrations
Co-ingestion of a protein hydrolysate and amino acid mixture with carbohydrate improves plasma glucose disposal in patients with type 2 diabetes
BACKGROUND: Although insulin secretion after carbohydrate ingestion is severely impaired in patients with type 2 diabetes, amino acid and protein co-ingestion can substantially increase plasma insulin responses. OBJECTIVE: We investigated insulin responses and the subsequent plasma glucose disposal rates after the ingestion of carbohydrate alone (CHO) or with a protein hydrolysate and amino acid mixture (CHO+PRO) in patients with a long-term diagnosis of type 2 diabetes. DESIGN: Ten type 2 diabetic patients [mean (+/-SEM) age: 62 +/- 2 y; body mass index (kg/m(2)): 27 +/- 1] and 9 healthy control subjects (age: 58 +/- 1 y; body mass index: 27 +/- 1) participated in 2 trials in which the plasma insulin response was measured after the ingestion of 0.7 g carbohydrate . kg(-1) . h(-1) with or without 0.35 g . kg(-1) . h(-1) of a mixture that contained a protein hydrolysate, leucine, and phenylalanine. Continuous infusions with [6,6-(2)H(2)]glucose were then given to investigate plasma glucose disposal. RESULTS: Plasma insulin responses were higher by 299 +/- 64% and 132 +/- 63% in the CHO+PRO trial than in the CHO trial in the diabetic patients and the matched control subjects, respectively (P < 0.001). The subsequent plasma glucose responses were reduced by 28 +/- 6% and 33 +/- 3% in the CHO+PRO trial than in the CHO trial in the diabetic patients and the matched control subjects, respectively (P < 0.001). The reduced plasma glucose response in the diabetic patients was attributed to a 13 +/- 3% increase in glucose disposal (P < 0.01). CONCLUSIONS: The combined ingestion of carbohydrate with a protein hydrolysate and amino acid mixture significantly increases de novo insulin production in patients with a long-term diagnosis of type 2 diabetes. The increased insulin response stimulates plasma glucose disposal and reduces postprandial glucose concentrations
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