OBJECTIVETo explore the effects of high altitude on cognitive flexibility.

METHODSSimulated hypoxia at an altitude of 3 600 m was performed in a hypobaric chamber. Twenty-three volunteers without hypoxic experience were selected and the mean age was about 25.1 years. The physiological parameters (heart rate, blood pressure and oxygen saturation) were measured. Task switch paradigm was used to explore the cognitive flexibility in each phase, and the changing anxiety state was evaluated simultaneously.

RESULTSReaction time (RT) switch cost in hypoxia phase showed a significant increase compared with the baseline; anxiety level in hypoxia phase was higher than the adaptation phase; a remarkable negative correlation between anxiety level and RT switch cost was found in adaptation phase, whereas a positive correlation was found in landing phase.

CONCLUSIONHigh altitude (3 600 m) affects cognitive flexibility and anxiety state. Anxiety before the hypoxia exposure improves the cognitive flexibility performance, while anxiety after the hypoxia exposure hampers the performance because of the post-hypoxia effect.

Adult ; Altitude ; Anxiety ; Cognition ; physiology ; Humans ; Hypoxia ; psychology ; Male ; Reaction Time

The effects of the feed attractants on Whitmania pigra were studied. The average weight of Wh. pigra were 5.0 g. Arginine was selected as feed attractants, xanthan gum was selected as feed substrate. The times of Wh. pigra going into the inducing room were recorded. The water temperature was 22-25 degrees C during the whole experiment. Arginine that had better inducing effect was chosen to carry on in the gradient experiment. The results showed that the best inducing effect was found when the added amount of arginine was 0.3%, which was close to the arginine content of the natural body fluid of Wh. Pigra and Bellamya purificata, 2.97 mg x g(-1).
Animal Feed ; analysis ; Animals ; Arginine ; analysis ; metabolism ; Body Weight ; Feeding Behavior ; Leeches ; growth & development ; physiology

Objective To analyze the pressure-driven streaming potential in a cancellous bone meso-mechanical model with numerical simulation, so as to understand characteristics of streaming potential distributions in cancellous bone. Methods Based on the control equations of electric field and fluid, the finite element method was used to calculate the streaming potential in the cancellous bone model when subjected to pressure. Results The streaming potential near the solid surface of the model was relatively large (about 43.4 μV), while the streaming potential away from the solid surface was smaller (about 19.7 μV). Pressure and Zeta potential had a significant impact on the streaming potential of the model, presenting a linear relationship with the streaming potential. The streaming potential was greatly affected when the ion concentration was low, whereas the effect on the streaming potential was small when the ion concentration was high. Conclusions This research finding provides a theoretical reference for prevention and treatment by stimulation methods of electric current and electromagnetic fields in clinical fractures, senile osteoporosis and other bone diseases.

OBJECTIVETo test the effects of autologous skeletal myoblast transplantation on the hemodynamics in dogs with coronary microembolization-induced chronic heart failure (CHF).

METHODSCHF models were successfully induced in 19 dogs and divided into ASMT group (n=9) and control group (n=10). The myoblasts were injected into the embolized region in the 9 dogs of the ASMT group, and saline was injected in the control dogs, and the hemodynamics of the dogs were evaluated 5 weeks after the injections.

RESULTCompared with saline injection, ASMT significantly increased dP/dtmax, MAP and LVSP (P<0.05) and decreased LVEDP (P<0.05) 5 weeks after myoblast transplantation. Desmin and Brd-U immunofluorescent staining showed myoblast survival at the injected sites in the dogs.

CONCLUSIONASMT provides mild improvements in the hemodynamics of dogs with CHF.

Animals ; Chronic Disease ; Dogs ; Female ; Heart Failure ; physiopathology ; therapy ; Hemodynamics ; Male ; Myoblasts, Skeletal ; transplantation ; Transplantation, Autologous

China ; Cost of Illness ; Demography ; Female ; Humans ; Maternal Mortality ; Poverty Areas

This study was purposed to investigate the efficacy of different whole flow lysis reagents for lysis of red blood cells in flow cytometric analysis. The expression of immunocytes was detected by flow cytometry after lysis of red blood cells using commercial reagents (Optilyse C, FACS Lysing Solution) and self-made red blood cell lysis reagents (RBC Lysis Buffer), the detection results were analyzed comparatively. The results showed that there was no significant difference in the percentage of CD3e(+), CD3e(+)CD4(+), CD3e(+)CD8a(+), CD3e(-)CD19(+), CD3e(-)NK1.1(+) and Gr-1(+) cells between 3 different lysis reagent groups. However OptiLyse C solution was suitable to Gr-1(+) cell detection, but did not suit to Foxp3(+) Treg detection. The self-made RBC Lysis Buffer and FACS Lysing Solution were suited to Foxp3(+) Treg detection. It is concluded that the use of self-made RBC Lysis Buffer for flow cytometry can get the lysis efficiency of commercially available lysis solutions when samples are prepared in accordance with standardized procedure. The self-made RBC Lysis Buffer not only can satisfy experimental requirements, but also can reduce the experimental costs.
Animals ; Erythrocyte Count ; Erythrocytes ; immunology ; metabolism ; Flow Cytometry ; instrumentation ; methods ; Immune System ; immunology ; Indicators and Reagents ; analysis ; Mice ; Mice, Inbred C57BL

OBJECTIVEAnalyzing the relationships between peripheral blood CD4+ CD25hi regulatory T (Treg) cells and peripheral blood immune status or plasma HIV-lviral load in HIV-infected individuals,so as to determine whether Treg were related to the progression of HIV-infected disease.

METHODS116 HIV-infected patients in different stages and 21 healthy control individuals were included in this study. The CD4+ and CD8+ T cell counts were determined by a standard 4-color flow cytometry technique. The Treg cells were examined with 3-color immune staining flow cytometry. The plasma HIV-1 viral load was detected by real time PCR.

RESULTSThe frequencies of Treg cells decreased in HIV-infected individuals with high CD4+ T cell counts( > 300/microl) compared with normal controls. With the progression of disease the frequencies of Treg cells were raised gradually, until were increased in HIV-infected individuals with low levels of CD4+ T cell counts ( < 100/microl). In addition, the frequencies of Treg cells were inversely related to CD4+ T cell counts and CD4+ /CD8+ ratio, data showed a statistically significant (respectively, r = -0.564, P < 0.001; r = -0.377, P < 0.001). Furthermore, the proportions of Treg cells were closely related to plasma HIV-1 RNA viral load (r = 0.514, P < 0.001).

CONCLUSIONCD4 CD25hi Treg cells should be a kind of important cells participating the immunopathogenesis of AIDS. It may play different roles in different stages of HIV-infected disease. The exact mechanism of Treg cells in the progression of the HIV-infected disease needs to be investigate further.

Adult ; Case-Control Studies ; Cells, Cultured ; Disease Progression ; Female ; HIV Infections ; immunology ; pathology ; virology ; HIV-1 ; genetics ; immunology ; isolation & purification ; Humans ; Interleukin-2 Receptor alpha Subunit ; immunology ; Male ; Middle Aged ; T-Lymphocytes, Regulatory ; immunology ; Viral Load

OBJECTIVEPulmonary surfactant protein-D (SP-D) is regarded as a valuable biomarker in acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). This study was to explore the changes of SP-D content in lung tissue following ALI and the effect of dexamethasone (Dex) on the SP-D content in young rats.

METHODSOne hundred and forty-four 21-day-old Sprague-Dawley rats were randomly assigned into control, ALI and Dex-treated groups. ALI was induced by intraperitoneal injection of lipopolysaccharide (LPS) (4 mg/kg) in the rats from the ALI and Dex-treated groups. Normal saline was given for the control group. Dex (5 mg/kg) was administered 1 hr after LPS injection in the Dex-treated group. At each time interval of 6, 12, 24, 36, 48 and 72 hrs after LPS injection, eight rats of each group were randomly chosen and sacrificed. Western blot was employed to detect the content of SP-D in lung tissues.

RESULTSThe pulmonary SP-D content decreased significantly at 36, 48 and 72 hrs after LPS administration in the ALI group, and reduced to a nadir (0.92 +/-0.11 vs 3.27 +/- 0.52) at 48 hrs compared with that of the control group (P < 0.01). The SP-D content in the Dex-treated group increased significantly at 36,48 and 72 hrs after LPS administration when compared with the ALI group (P < 0.01). A significant difference in the SP-D content between the Dex-treated and the control group was noted only at 72 hrs after LPS administration (P < 0.05).

CONCLUSIONSThe SP-D content in lung tissue was reduced following ALI in young rats at the early stage. Early administration of Dex can significantly increase the pulmonary SP-D content.

Animals ; Dexamethasone ; therapeutic use ; Lipopolysaccharides ; toxicity ; Lung ; chemistry ; Pulmonary Surfactant-Associated Protein D ; analysis ; Rats ; Rats, Sprague-Dawley ; Respiratory Distress Syndrome, Adult ; drug therapy ; metabolism

OBJECTIVESTo observe the role of PPARgamma during the activation process of hepatic stellate cells (HSC).

METHODSBy morphology and RT-PCR, we study the changes of expression of PPARgamma in culture-activated HSC or in vivo activated HSC induced by dimethylnitrosamine (DMN).

RESULTSIn vitro, the expression level of PPARgamma in freshly isolated HSC (0.72+/-0.01) significantly reduced to 0.48+/-0.03 on the third day of culture (t = 19.8372, P<0.01), and reduced 70% on the seventh culture-day and could not be detected after the second passage. In vivo, HSC freshly isolated from normal control rats expressed PPARgamma (0.76+/-0.01). During the development of rat liver fibrosis induced by DMN, the expression level significantly reduced to 0.46+/-0.02 after the third injection of DMN (t = 29.5318, P<0.01), and reduced 66% on the end of first week and could not be detected on the end of second and third week.

CONCLUSIONThe expression of PPARgamma might play an important role on the maintenance of resting-form of HSC, and the reduction of expression of PPARgamma might be an early event during the activation process of HSC.

Animals ; Liver ; cytology ; Liver Cirrhosis ; etiology ; pathology ; Male ; RNA, Messenger ; analysis ; Rats ; Rats, Wistar ; Receptors, Cytoplasmic and Nuclear ; physiology ; Transcription Factors ; physiology

OBJECTIVEPulmonary surfactant protein A (SP-A) plays an important role in the maintenance of pulmonary surfactant function and innative immune defence. This study aimed to explore the changes of SP-A concentration in the lungs of young rats with acute lung injury.

METHODSSprague-Dawley rats were randomly assigned to control and lung injury groups. Acute lung injury was induced by intraperitoneal injection of lipopolysaccharide (LPS) (4 mg/kg) in the lung injury group. The same amount of normal saline was given for the control group. The two groups were subdivided into 6 groups sacrificed at 6, 12, 24, 36, 48 and 72 hrs of injection (n=8 each). Western blot was employed to detect SP-A concentration in the lung tissues.

RESULTSSP-A concentration in the lung injury group was not different from the the control group within 12 hrs after LPS injection. SP-A concentration in the lung injury group was elevated significantly during 24-48 hrs after LPS injection, peaking at 36 hrs (6.94+/-0.80 vs 5.01+/-0.36; P< 0.01), compared with the controls. However, SP-A concentration in the lung injury group was significantly reduced 72 hrs after LPS injection compared with the controls (P< 0.01).

CONCLUSIONSThe changes of lung SP-A concentration in rats following acute lung injury were time-dependent. The transient elevation of SP-A concentration in the lungs indicated a strong compensation ability of SP-A in the host defence against acute lung injury.

Animals ; Female ; Lipopolysaccharides ; toxicity ; Lung ; chemistry ; Male ; Pulmonary Surfactant-Associated Protein A ; analysis ; Rats ; Rats, Sprague-Dawley ; Respiratory Distress Syndrome, Adult ; metabolism