OBJECTIVETo observe temperature and pressure changes inside plethysmograph produced by body temperature of anesthetized mice.

METHODSThe temperature and pressure changes inside whole body plethysmograph generated from anesthetized mice were compared with those from dead mice. The temperature and pressure changes inside body chamber and head chamber of double-chamber with anesthetized mice in body chamber were synchronously measured. The respiratory frequencies and amplitudes of mice inside two kinds of head-out plethysmographs were synchronously measured. One of these two plethysmographs kept sealed all the time and the other was opened to the atmosphere for 1 min every 2 min.

RESULTTemperature and pressure of air in the anesthetized mice chamber increased 1.18 degree and 2.710 mmHg within 6 min, and data from dead mice were 1.17 degree and 2.671 mmHg. There were no significant differences between these two groups. The temperature inside body chamber increased 1.92 degree in 20 min and the pressure was 5.554 mmHg, which were significantly higher than those of head chamber (0.09 degree and 0.627 mmHg). The respiratory frequencies of mice in the sealed head-out plethysmograph increased from 125.04 per min to 168.45 per min, and amplitudes of pressure changes generated from mice breath decreased from 1.090 mmHg to 0.883 mmHg. Significant differences occurred between different observation time points. Meanwhile respiratory frequencies in the open head-out plethysmograph were around 120 per min and amplitude of pressure changes kept about 1 mmHg. There were no significant differences between different time points.

CONCLUSIONIncrease of temperature and pressure inside pressure whole-body plethysmograph are mainly from body temperature of mice, and the increased pressure significantly influences respiration of mice.

Animals ; Body Temperature ; Mice ; Plethysmography, Whole Body ; Pressure ; Temperature

When using pressure-type plethysmography to test lung function of rodents, calculation of lung volume is always based on Boyle's law. The precondition of Boyle's law is that perfect air is static. However, air in the chamber is flowing continuously when a rodent breathes inside the chamber. Therefore, Boyle's law, a principle of air statics, may not be appropriate for measuring pressure changes of flowing air. In this study, we deduced equations for pressure changes inside pressure-type plethysmograph and then designed three experiments to testify the theoretic deduction. The results of theoretic deduction indicated that increased pressure was generated from two sources: one was based on Boyle's law, and the other was based on the law of conservation of momentum. In the first experiment, after injecting 0.1 mL, 0.2 mL, 0.4 mL of air into the plethysmograph, the pressure inside the chamber increased sharply to a peak value, then promptly decreased to horizontal pressure. Peak values were significantly higher than the horizontal values (P<0.001). This observation revealed that flowing air made an extra effect on air pressure in the plethysmograph. In the second experiment, the same volume of air was injected into the plethysmograph at different frequencies (0, 0.5, 1, 2, 3 Hz) and pressure changes inside were measured. The results showed that, with increasing frequencies, the pressure changes in the chamber became significantly higher (P<0.001). In the third experiment, small animal ventilator and pipette were used to make two types of airflow with different functions of time. The pressure changes produced by the ventilator were significantly greater than those produced by the pipette (P<0.001). Based on the data obtained, we draw the conclusion that, the flow of air plays a role in pressure changes inside the plethysmograph, and the faster the airflow is, the higher the pressure changes reach. Furthermore, the type of airflow also influences the pressure changes.
Air Movements ; Animals ; Models, Theoretical ; Plethysmography, Whole Body ; instrumentation ; methods ; Pressure ; Rats ; Respiration

The in vivo techniques for studying human body composition have built up an important field and are continuing to be developed. This review provides an overview of the present status of this field and describes the in vivo techniques used in mearsuring human body composition such as anthropometry, metabolites method, densitometry, dilution method, total body potassium, neutron activation analysis, bioelectrical impedance analysis, dual energy X ray absorptiometry and imaging method. The review also introduces the principle, method and value of these techniques.
Anthropometry ; methods ; Body Composition ; Densitometry ; methods ; Humans ; Magnetic Resonance Spectroscopy ; methods ; Plethysmography, Impedance ; methods ; Whole Body Imaging ; methods

OBJECTIVETo evaluate the accordance of tidal volume (TV) with thoracic inflating volume (TIV) measured by pressure whole-body or double-chamber plethysmography in mice.

METHODSTV and TIV by double-chamber plethysmography were simultaneously measured in 6 mice with spontaneous respiratory frequencies 90 - 120/min; TV and TIV by whole-body plethysmography were measured in 8 paralyzed mice ventilated by fixed frequency.

RESULTTIV value by double-chamber plethysmography was significantly higher than TV [(0.369 +/- 0.014) ml vs (0.356 +/- 0.012) ml, P < 0.01)] in 6 spontaneously breathing mice. TIV value by whole-body plethysmography was significantly lower than TV[(0.233 +/- 0.003) ml vs 0.3 ml, P < 0.001] in 8 paralyzed mice.

CONCLUSIONThe TV value assessed by TIV measurement can not be accurate, because of the humidifying and heating of inhaled air and negative thoracic pressure during the measurement.

Animals ; Female ; Mice ; Mice, Inbred BALB C ; Plethysmography, Whole Body ; Respiratory Function Tests ; Thorax ; physiopathology ; Tidal Volume

PURPOSE: Asthma is a complex disease that is characterized by airway hyperresponsiveness (AHR), reversible airway obstruction, and inflammation, marked mainly by eosinophilic infiltration. The bulk of the evidence identifies alphaCD4(+) TH2 cells as having a pivotal role in mediating the inflammation that is central to asthma but The role of CD8(+) T cells in the development of allergic airway disease is still controversial. The purpose of this study was to investigate the role of CD8(+) T cells in the development of AHR and airway inflammation in mouse model of chronic asthma. METHODS: Mice were sensitized to OVA by i.p. injection on day 1, 14 and then challenged by OVA intranasal instillation on days 27, 28, 29 47, 61, 73, 74 and then 75 days. Anti-CD8 antibody was administered to sensitized mice by i.v. injection 2h before second sensitization, day 27 and 73. In vivo airway responsiveness was measured by whole body plethysmography (Penh) to inhaled methacholine (MCh) on day 77. Lung eosinophilia, bronchoalveolar lavage fluid (BALF) cytokine levels were also assessed. RESULTS: Sensitized and challenged mice showed significant airway eosinophilia and heightened AHR to methacholine when compared with non-sensitized animals. Administration of anti-CD8 antibody prevented both development of AHR as well as BALF eosinophilia. Treatment with anti-CD8 antibody also resulted in supression of IL-5 production in BALF. CONCLUSION: These results indicate that CD8 (+) T cell may have a potential role in the development of chronic allergic airway inflammation and development of allergen-induced airway responses in mouse model.
Airway Obstruction ; Animals ; Asthma ; Bronchoalveolar Lavage Fluid ; Eosinophilia ; Eosinophils ; Inflammation ; Interleukin-5 ; Lung ; Methacholine Chloride ; Mice ; Negotiating ; Ovum ; Plethysmography, Whole Body ; T-Lymphocytes ; Th2 Cells

PURPOSE: Allergic asthma is a complex syndrome of reactions within the airways characterized by bronchoconstriction, airway inflammation and airway hyperresponsiveness (AHR). There is an emerging body of knowledge defining the role of CD8 (+) T cells in the pathogenesis of allergic asthma. The role of CD8 (+) T cells in the development of allergic airway disease is still controversial. The purpose of this study was to investigate the role of CD8 (+) T cells during the induction of allergen-induced AHR and airway inflammation. METHODS: Mice were sensitized to OVA by i.p. injection on day 1, 14 and then challenged by OVA inhalation on days 24, 25, 26. Anti-CD8 antibody was administered to sensitized mice by i.v. injection 2h before second sensitization and first airway challenge. In vivo airway responsiveness was measured by whole body plethysmography (Penh) to inhaled methacholine (MCh) on day 28. Lung eosinophilia, bronchoalveolar lavage fluid (BALF) cytokine levels were also assessed. RESULTS: Sensitized and challenged mice showed significant airway eosinophilia and heightened responsiveness to methacholine when compared with nonsensitized animals. Administration of anti-CD8 antibody prevented both development of AHR as well as bronchoalveolar lavage fluid eosinophilia. Anti-CD8 antibody abolished peribronchial and perivascular infiltration of inflammatory cells. Treatment with anti-CD8 antibody also resulted in supression of IL-5 production in bronchoalveolar lavage fluid. CONCLUSION: These results indicate that CD8 (+) T cell may have a potential role in the development of allergic airway inflammation and development of allergen-induced airway responses.
Animals ; Asthma ; Bronchoalveolar Lavage Fluid ; Bronchoconstriction ; Eosinophilia ; Inflammation* ; Inhalation ; Interleukin-5 ; Lung ; Methacholine Chloride ; Mice ; Ovum ; Plethysmography, Whole Body ; T-Lymphocytes*

BACKGROUND: Low spirometric forced vital capacity(FVC) in conjunction with a normal or high ratio of the forced expiratory volume at 1 second to the forced vital capacity(FEV1/FVC%) has traditionally been classified as a restrictive abnormality. However, the gold-standard diagnosis of a restrictive pulmonary impairment requires a measurement of the total lung capacity (TLC). This study was performed to determine the predictive value of spirometric measurements of the FVC for diagnosing a restrictivepulmonary abnormality. METHODS: Test results from 1,371 adult patients who undertook both spirometry and lung volume measurements on the same visit from January 1999 to December 2000 were enrolled in this study. The test values for the FVC, the TLC that was below 80% of predicted value, and a FEV1/FVC% that was below 70%, were classified as being abnormal. RESULTS: Of the 1,371 patients, 353 patients had a reduced a FVC. Of these patients, 186 patients had a reduced TLC. Therefore, the positive predictive value was 52.7%. Of the 196 patients with a normal FEV1/FVC% and a reduced FVC, 148(75.5%) patients had a lower TLC. Thirty eight (24.2%) patients out of 157 patients with a low FEV1/FVC% and a low FVC showed a restrictive defect. CONCLUSION: Spirometry is useful to rule out a restrictive pulmonary abnormality, but a restrictive pattern on the spirometry dose not mean there is a true restrictive disease. For the patients with a low FVC, TLC measurements are essential for diagnosing a restrictive pulmonary impairment.
Adult ; Diagnosis ; Forced Expiratory Volume ; Humans ; Lung Volume Measurements ; Plethysmography, Whole Body ; Respiratory Function Tests ; Spirometry* ; Total Lung Capacity ; Vital Capacity

PURPOSE: Respiratory syncytial virus is the primary cause of pneumonia and bronchiloitis in young children and infants. RSV infection is also known to be very important to asthma patient, because previous RSV infection increases the frequency of the asthma development and RSV infection may cause airway hyperresponsiveness. Natural RSV infection does not provide complete immunity and reinfection occurs throughout life. Several strategies have recently been used in RSV vaccine development, including the generation of formalin inactivated RSV(FI-RSV), peptides, recombinant vaccine viruses (rVV), and DNA based vaccines. Previous studies in mice primed with RSV G protein enhanced lung pathology resulted from a Th2 host immune response against the viral G protein. We studied for the evaluation of protective immunity, effect on airway hyperesponsiveness, and influence on lung pathology after pND G immunization. METHODS: BALB/c mice were injected with pND G(50g in 1 g/l PBS), pND G-HA (50 g), pND(50 g) FI-RSV(10 6PFU) i.d.at 0, 2, 4 weeks. Four weeks later, mice were challenged with RSV(10 6PFU). Mice were sacrificed on postchallenge day 4 and their lungs were removed for RT-PCR and viral titration. The other mice were sacrificed on postchallenge day 6 for bronchoalveolar lavage, serum and histologic examination. Airway responsiveness was assessed by using a single chamber whole body plethysmography on post challenge day 5. RESULTS: 1) Vaccination with pND-G reduced the Mch(methacholine) induced airway hyperresponsiveness after RSV infection(P<0.05). 2) Viral titers are decreased in pND-G group and FI-RSV group(P<0.05) and complete protection from RSV infection was 9/12(75%) in pND-G group. 3) Serum anti-G IgG antibody is more increased in pND-G group than RSV group(P<0.05). 4) IFN-/IL-5 ratio is increased in pND-G group(0.59) and decreased in FI-RSV group(P<0.036). 5) Inflammatory response in BAL after RSV infection was decreased by pND-G vaccination(P>0.05). CONCLUSION: In this study, immunization with pND encoding G protein induced decrease in airway hyperresponsiveness, and protection against RSV infection of the lower respiratory tract infection and also induced virus neutralizing antibody and decrease in lymphocytic inflammation. pND G immunization elicited balanced pulmonary Th1/Th2 cytokine response without atypical pulmonary inflammatory responses.
Animals ; Antibodies, Neutralizing ; Asthma ; Bronchoalveolar Lavage ; Child ; DNA* ; Formaldehyde ; GTP-Binding Proteins ; Humans ; Immunization* ; Immunoglobulin G ; Infant ; Inflammation ; Lung ; Mice ; Pathology ; Peptides ; Plethysmography, Whole Body ; Pneumonia ; Respiratory Syncytial Viruses* ; Respiratory Tract Infections ; Vaccination ; Vaccines

BACKGROUND: Airway responsiveness after acute inhalation of ozone is related to the concentration and duration of ozone exposure. Using barometric whole-body plethysmography and increase in enhanced pause (Penh) as an index of airway obstruction, we measured the response of BALB/c mice to acute ozone inhalation to study the time course change of pulmonary function after ozone exposure. METHODS: Penh was measured before and after exposure to filtered air or 0.12, 0.5, 1, or 2 ppm ozone for 3 hr (n=6/group). In addition, Penh was measured 24, 48 and 72 hr after ozone exposure. Bronchoalveolar lavage (BAL) and histopathologic examinations were performed. RESULTS: The increase in Penh after ozone exposure was significantly higher in the 0.12, 0.5, 1 and 2 ppm groups compared with the control group (all p< 0.01). Increases in Penh 24 hr after ozone exposure were significantly lower than those immediately after acute ozone exposure; however, increases in Penh 72 hr after ozone exposure were significantly higher than those in the control group (each p< 0.01). The proportion of neutrophils in BAL fluid was significantly higher in the group exposed to 2 ppm ozone than in the groups exposed to filtered air or 0.12 ppm ozone (both p< 0.01). CONCLUSION: These results indicate that airway obstruction is induced following ozone exposure in a concentration-dependent manner and persists for at least 72 hr.
Airway Obstruction/*etiology/*pathology ; Animals ; Animals, Newborn ; Bronchoalveolar Lavage Fluid/cytology ; Disease Models, Animal ; Female ; Mice ; Mice, Inbred BALB C ; Plethysmography, Whole Body/*methods ; Probability ; Reference Values ; Respiratory Function Tests ; Risk Assessment ; Sensitivity and Specificity ; Statistics, Nonparametric ; Sulfuric Acids/*adverse effects

OBJECTIVEBody plethysmography is a typical method to measure functional residual capacity (FRC) and airway resistance (Raw). The aim of the study was to test the feasibility of measuring lung function with the body plethysmography in young children with acute lower respiratory tract infection (ALRI) by evaluating changes and prognosis of lung function for infants with ALRI with or without wheezing via body plethysmograph.

METHODPulmonary function tests (PFTs) were performed by using body plethysmography in 444 children with ALRI, aged 1-36 months, to assess their tidal breathing parameters such as ratio of time to peak tidal expiratory flow to total expiratory time (TPTEF/TE), ratio of volume to peak tidal expiratory flow to total expiratory volume (VPTEF/VE), plethysmographic functional residual capacity (FRCP), FRCP per kilogram (FRCP/kg), specific effective airway resistance (sReff), effective airway resistance (Reff), Reff per kilogram (Reff/kg), etc. According to whether there was wheezing or not, children who had ALRI with wheezing were classified as Group-W, or without wheezing as Group-N. Changes or correlations of tidal breathing parameters and plethysmographic parameters were compared.One hundred and three contemporaneous healthy controls aged 1-36 months underwent the same tests for comparison. And 36 wheezing children accepted PFTs at follow-up in recovery phase.

RESULTMean values of TPTEF/TE in Group-W,Group-N and the Control respectively were (20.5 ± 6.7)%,(22.8 ± 6.5)%,(34.6 ± 5.0)% (F = 110.500, P < 0.001), while VPTEF/VE respectively were (23.0 ± 6.3)%,(25.2 ± 6.8)%,(34.5 ± 4.2)% (F = 107.800, P < 0.001). Compared to the Control,Group-W and Group-N had significantly higher values of FRCP (226 vs. 176 vs. 172 ml, χ(2) = 64.870, P < 0.001), FRCP/kg(24.40 vs.17.80 vs.17.60 ml/kg,χ(2) = 68.890, P < 0.001), sReff(1.00 vs. 0.52 vs. 0.46 kPa·s,χ(2) = 75.240, P < 0.001), Reff (3.90 vs.2.74 vs.2.20 kPa·s/L, χ(2) = 36.480, P < 0.001) and Reff/kg [0.42 vs. 0.29 vs.0.22 kPa·s/(L·kg), χ(2) = 29.460, P < 0.001]. Although 25 (12.8%) wheezing children with ALRI had normal values of tidal breathing parameters, they already had increased FRCP, FRCP /kg, sReff, Reff and Reff/kg (t = 2.221, 1.997, 2.502, 2.587, 2.539, all P < 0.05). Values of FRCP and Reff in infants caught ALRI were inversely correlated to that of TPTEF/TE and VPTEF/VE (P < 0.05); 36 children with wheezing who accepted PFTs at follow-up had shown significant decline in the specific parameters of plethysmography such as FRCP, FRCP/kg, sReff, Reff and Reff/kg (Z = -1.999, -2.195, -2.038, -1.823, -2.054, all P < 0.05), while no improvement in the main parameters of tidal breathing such as TPTEF/TE.

CONCLUSIONMeasuring lung function with the body plethysmography in young children with ALRI is feasible. FRC and Raw, as special lung function testing parameters of body plethysmography, were sensitive indicators reflecting impairment of lung function in infants with ALRI (especially for children caught ALRI with wheezing) and shows significant correlation with parameters from lung function testing via tidal breathing. Therefore plethysmography is worthy of clinical promotion.

Airway Resistance ; physiology ; Case-Control Studies ; Child, Preschool ; Female ; Functional Residual Capacity ; physiology ; Humans ; Infant ; Lung ; physiopathology ; Male ; Plethysmography, Whole Body ; Respiratory Function Tests ; Respiratory Sounds ; diagnosis ; physiopathology ; Respiratory Tract Diseases ; diagnosis ; physiopathology ; Tidal Volume