Continuous positive airway pressure increases inspiratory capacity of COPD patients

Background and objective: Hyperinflation with a decrease in inspiratory capacity (IC) is a common presentation for both unstable and stable COPD patients. As CPAP can reduce inspiratory load, possibly secondary to a reduction in hyperinflation, this study examined whether CPAP would increase IC in stable COPD patients. Methods: Twenty-one stable COPD patients (nine emphysema, 12 chronic bronchitis) received a trial of CPAP for 5 min at 4, 7 and 11 cmH(2)O. Fast and slow VC (SVC) were measured before and after each CPAP trial. In patients in whom all three CPAP levels resulted in a decreased IC, an additional trial of CPAP at 2 cmH(2)O was conducted. For each patient, a `best CPAP` level was defined as the one associated with the greatest IC. This pressure was then applied for an additional 10 min followed by spirometry. Results: Following application of the `best CPAP`, the IC and SVC increased in 15 patients (nine emphysema, six chronic bronchitis). The mean change in IC was 159 mL (95% CI: 80-237 mL) and the mean change in SVC was 240 mL (95% CI: 97-386 mL). Among these patients, those with emphysema demonstrated a mean increase in IC of 216 mL (95% CI: 94-337 mL). Six patients (all with chronic bronchitis) did not demonstrate any improvement in IC. Conclusions: The best individualized CPAP can increase inspiratory capacity in patients with stable COPD, especially in those with emphysema.

Effect of Weight Loss on Aerobic Capacity in Patients with Severe Obesity Before and After Bariatric Surgery

Severe obesity has been associated with adverse effects on physical capacity. In a prospective study, the aerobic capacity of severely obese patients was measured in order to observe the physiological response to weight loss from bariatric surgery. Sixty-five consecutive patients (40.4 +/- 8.4 years old; 93.8% female; body mass index = 49.4 +/- 5.4 kg/m(2)) were evaluated before bariatric surgery and then 6 and 12 months after surgery. Aerobic capacity was assessed with a scientific treadmill to measure maximal oxygen consumption (VO(2max)), heart rate, blood pressure, time on the treadmill, and distance walked (modified Bruce test). For the three observational periods, VO(2max) was 25.4 +/- 9.3, 29.8 +/- 8.1, and 36.7 +/- 8.3 ml/kg/min; time on the treadmill was 5.4 +/- 1.4, 6.4 +/- 1.6, and 8.8 +/- 1.0 min; and distance walked was 401.8 +/- 139.1, 513.4 +/- 159.9, and 690.5 +/- 76.2 m. For these variables, significant results (p = 0.0000) were observed for the two postoperative periods in relation to the preoperative period. Severely obese individuals increased their aerobic capacity after successful bariatric surgery. The data also suggests that a positive and progressive relationship between weight loss and improvement in fitness as a moderate loss of weight 6 months after surgery already showed some benefit and an additional reduction in weight was associated with a better performance in the aerobic capacity tests at the 12-month follow-up.

Simultaneous two-wavelength holographic interferometry in a superorbital expansion tube facility

A new variation of holographic interferometry has been utilized to perform simultaneous two-wavelength measurements, allowing quantitative analysis of the heavy particle and electron densities in a superorbital facility. An air test gas accelerated to 12 km/s was passed over a cylindrical model, simulating reentry conditions encountered by a space vehicle on a superorbital mission. Laser beams with two different wavelengths have been overlapped, passed through the test section, and simultaneously recorded on a single holographic plate. Reconstruction of the hologram generated two separate interferograms at different. angles from which the quantitative measurements were made. With this technique, a peak electron concentration of (5.5 +/- 0.5) x 10(23) m(-3) was found behind a bow shock on a cylinder. (C) 1997 Optical Society of America.

Six-minute walk test: functional capacity of severely obese before and after bariatric surgery

Background: The 6-minute walk test (6MWT) is a well-known instrument for assessing the functional capacity of a variety of groups, including the obese. It is a simple, low-cost and easily applied method to objectively assess the level of exercise capacity. The aim of the present study was to study the functional capacity of a severely obese population before and after bariatric surgery. Methods: A total of 51 patients were studied. Of the 51 patients, 86.2% were women, and the mean age was 40.9 +/- 9.2 years. All 51 patients were evaluated preoperatively and 49 were evaluated 7-12 months postoperatively. The initial body mass index was 51.1 +/- 9.2 kg/m(2), and the final body mass index was 28.2 +/- 8.1 kg/m(2). All patients underwent Roux-en-Y gastric bypass. The 6MWT was performed in a hospital corridor, with patients attempting to cover as much distance as they could, walking back and forth for as long as possible within 6 minutes at their regular pace. The total distance, Borg Scale of perceived exhaustion, modified Borg dyspnea scale for shortness of breath, and physical complaints at the end of the test were recorded. In addition, the heart rate and respiratory frequency were assessed before and after the test. Results: The tolerance was good, and no injuries occurred at either evaluation. The patients` mean distance for the 6MWT was 381.9 +/- 49.3 m before surgery and 467.8 +/- 40.3 m after surgery (p < .0001). Similar results were observed for the other parameters assessed. Conclusion: The 6MWT provided useful information about the functional status of the obese patients undergoing bariatric surgery. A simple, safe, and powerful method to assess functional capacity of severely obese patients, the 6MWT is an objective test that might replace the conventional treadmill test for these types of patients. (Surg Obes Relat Dis 2009;5:540-543.) (C) 2009 American Society for Metabolic and Bariatric Surgery. All rights reserved.

Choroidal expansion during the water drinking test

To evaluate the correlation between intraocular pressure (IOP) rise, ocular pulse amplitude (OPA), and choroidal thickness (ChT) during the water drinking test (WDT). Primary open-angle glaucoma (POAG) patients were submitted to the WDT followed by serial IOP measurements using dynamic contour tonometry (DCT), Goldman tonometry (GAT), and ChT measurements using ultrasonographic A and B-scan (USG). A control group not submitted to the test was also evaluated using DCT, GAT, and USG. Intraclass correlation coefficient (ICC) was calculated in the control group in order to assess the reproducibility of measurements. Spearman`s coefficient (rho) was used to assess the correlation between the variables. Thirty eyes were included in the study. There was a significant IOP rise during the WDT using both GAT and DCT (p < 0.001). The OPA and ChT measurements also increased significantly (p < 0.001). Spearman`s correlation between the OPA values and ChT measurements was significant and moderate (rho = 0.40, p = 0.005). The average increase of OPA and ChT measurements occurred 15 min before the IOP rise. There was a significant increase of OPA and ChT measurements followed by an IOP rise during the WDT. Increased choroidal volume due to hemodynamic forces may be enrolled in the mechanism of IOP elevation during this stress test.

Analysis of cell cycle phases and proliferative capacity in mice bearing melanoma maintained on different dietary proteins

Background Diet seems to represent, directly or indirectly, 35% of all cancer reports. In this study, the influence of dietary protein on the growth of melanoma B16F10 was evaluated through analyses of cell cycle phases and proliferative capacity. Methods Flow cytometry and argyrophilic nucleolar organizer regions (AgNORs) technique were applied in mice bearing B16F10 melanoma cells fed on different dietary proteins. All data were submitted to statistical analyses. Results The G0/G1 phase increased for the animal groups fed bovine collagen hydrolysate (BCH) or BCH-P1 + whey protein isolate (WPI), compared with mice receiving only WPI, for all dietary groups treated and nontreated with paclitaxel. Mice that received BCH + WPI treated with paclitaxel showed the highest percentage of apoptosis compared with WPI group. AgNORs, total nucleolar organizer regions (NORs)/cells and dot number/cell for all dietary protein groups nontreated with paclitaxel were higher than for the WPI. The only two dietary protein groups treated with paclitaxel that presented higher total NORs and dot number/cell than the WPI group were BCH + WPI and BCH-P1 + WPI. Conclusions A significantly lower proliferative capacity and larger number of cells in the G0/G1 phase were observed for the dietary protein groups combining the two collagen hydrolysates, BCH or BCH-P1 with WPI, treated with paclitaxel. Castro GA, Maria DA, Rodrigues CJ, Sgarbieri VC. Analysis of cell cycle phases and proliferative capacity in mice bearing melanoma maintained on different dietary proteins.

Wave expansion of CD(34+) progenitor cells in the spleen in rodent malaria

Defense against malaria depends upon amplification of the spleen structure and function for the clearance of parasitized red blood cells (pRBC). We studied the distribution and amount of CD(34+) cells in the spleens of mice infected with rodent malaria. We sought to identify these cells in the spleen and determine their relationship to infection. C57BL/6J mice were infected with self-resolving, Plasmodium chabaudi CR, or one of the lethal rodent malaria strains, P. chabaudi AJ and P. berghei ANKA. We then recorded parasitemia, mortality, and the presence of CD(34+) cells in spleen, as determined by immunohistochemistry and flow cytometry. In the non-lethal strain, the spleen structure was maintained during amplification, but disrupted in lethal models. The abundance of CD(34+) cells increased in the red pulp on the 4th and 6th days p.i. in all models, and subsided on the 8th day p.i. Faint CD(34+) staining on the 8th day p.i., was probably due to differentiation of committed cell lineages. In this work, increase of spleen CD(34+) cells did not correlate with infection control. (c) 2009 Published by Elsevier Inc.

Adipose tissue mesenchymal stem cell expansion in animal serum-free medium supplemented with autologous human platelet lysate

BACKGROUND: Mesenchymal stem cells (MSCs) have been considered for human regenerative therapy applications, and safe culture and expansion protocols are needed especially in the context of interspecies contamination. Human platelet lysate (PL) has been proposed as animal serum substitute during in vitro MSC expansion. In this work, a simplified and efficient method to obtain autologous PL to replace animal serum in cell culture applications is described. STUDY DESIGN AND METHODS: PL obtained by freezing and centrifugation procedures was tested as medium supplement for human adipose mesenchymal stem cell (hASC) culture. Differential proliferation, immunophenotypic changes, and differentiation under PL or fetal bovine serum (FBS) were assessed. RESULTS: In contrast to 10% FBS supplementation, cell population doubling time was significantly lower when hASCs were cultured with the same concentration of PL ( PL 22.9 +/- 1.5 hr vs. FBS 106.7 +/- 6.5 hr, t test, p < 0.05). Furthermore, hASCs maintained with 2.5% PL supplementation also showed satisfactory results. Immunophenotypic analysis revealed no differences between hASCs cultivated with PL or FBS supplementation and both cultures retained the potential to differentiate into adipose cells. These results demonstrate that autologous PL obtained from the same donor can be used as animal serum substitute in hASC culture. CONCLUSIONS: Taken together, evidence is provided that platelets provided by a single donor are sufficient to obtain PL for hASC propagation for clinical-scale applications mitigating the potential untoward side effects associated with the use of animal-derived reagents.