Animals ; Diaphragm ; physiopathology ; Electrophysiological Phenomena ; physiology ; Hypoxia ; physiopathology ; Male ; Rats ; Rats, Wistar ; Sleep Apnea Syndromes ; physiopathology

OBJECTIVE: To explore the role of diaphgram fatigue in the death from hanging with bound upper limbs of rabbits. METHODS: Rabbits were hanged with upper limbs bound, then the data of EMGdi were gathered RESULTS: By analyzing power spectral of EMGdi in experiment, we compare the ratio change of H/L between pre-experiment and post-experiment. There is a significance decrease of the ratio of H/L, so it indicates that diaphgram fatigue does exist. CONCLUSION Diaphgram fatigue plays an important role in the death from hanging with limbs of rabbits bound.
Animals ; Asphyxia/physiopathology* ; Cause of Death ; Diaphragm/physiopathology* ; Electromyography ; Female ; Forensic Medicine ; Male ; Muscle Fatigue ; Rabbits

AIMTo study the possibility that responses of fever and discharge of neurons in PVN to intraperitoneal administration of LPS are mediated by vagal afferents.

METHODSRectal temperature of rat was detected by digital temperature detecting instrument. Glass micropipette placed in PVN was used to record unit discharges of neurons in it, before and after LPS was injected into PVN in normal rats and vagotomy rats.

RESULTSThe rectal temperature change value in vagotomy LPS group was significantly decreased compared with that in sham LPS group, and there was striking difference between them (P < 0.05). The discharges of neurons in PVN was increased in the normal rat in response to LPS. The discharges of neurons in PVN had no significant change in the vagotomy rats in response to LPS.

CONCLUSIONThe results indicate that vagus nerve may be one of the pathways of peripheral LPS signal communicating to CNS.

Animals ; Diaphragm ; innervation ; Fever ; chemically induced ; physiopathology ; Lipopolysaccharides ; Male ; Neurons ; physiology ; Paraventricular Hypothalamic Nucleus ; physiopathology ; Rats ; Rats, Wistar ; Vagotomy, Truncal

Background: Neural respiratory drive (NRD) using diaphragm electromyography through an invasive transesophageal multi-electrode catheter can be used as a feasible clinical physiological parameter in patients with chronic obstructive pulmonary disease (COPD) to provide useful information on the treatment response. However, it remains unknown whether the surface diaphragm electromyogram (EMGdi) could be used to identify the deterioration of clinical symptoms and to predict the necessity of hospitalization in acute exacerbation of COPD (AECOPD) patients. Methods: COPD patients visiting the outpatient department due to acute exacerbation were enrolled in this study. All patients who were subjected to EMGdi and classical parameters such as spirometry parameters, arterial blood gas analysis, COPD assessment test (CAT) score, and the modified early warning score (MEWS) in outpatient department, would be treated effectively in the outpatient or inpatient settings according to the Global Initiative for Chronic Obstructive Lung Disease guideline. When the acute exacerbation of the patients was managed, all the examination above would be repeated. Results: We compared the relationships of admission-to-discharge changes (Δ) in the normalized value of the EMGdi, including the change of the percentage of maximal EMGdi (ΔEMGdi%max) and the change of the ratio of minute ventilation to the percentage of maximal EMGdi (ΔVE/EMGdi%max) with the changes of classical parameters. There was a significant positive association between ΔEMGdi%max and ΔCAT, ΔPaCO, and ΔpH. The change (Δ) of EMGdi%max was negatively correlated with ΔPaO/FiOin the course of the treatment of AECOPD. Compared with the classical parameters including forced expiratory volume in 1 s, MEWS, PaO/FiO, the EMGdi%max (odds ratio 1.143, 95% confidence interval 1.004-1.300) has a higher sensitivity when detecting the early exacerbation and enables to predict the admission of hospital in the whole cohort. Conclusions The changes of surface EMGdi parameters had a direct correlation with classical measures in the whole cohort of AECOPD. The measurement of NRD by surface EMGdi represents a practical physiological biomarker, which may be helpful in detecting patients who should be hospitalized timely.
Diaphragm ; physiopathology ; Electromyography ; methods ; Forced Expiratory Volume ; physiology ; Hospitalization ; Humans ; Pulmonary Disease, Chronic Obstructive ; metabolism ; physiopathology ; Spirometry ; Vital Capacity ; physiology

OBJECTIVEAim of this study was to investigate functions of lower esophageal sphincter (LES) barrier and esophageal clearance in fasting and postprandial stages in gastroesophageal reflux disease (GERD).

METHODSEight patients with confirmed GERD and 8 healthy subjects (HS) were observed in the study. The esophageal pH and manometry were recorded simultaneously for 1 h during fasting and 2 h after a meal (1,675 kJ) using pneumohydrolic capillary perfusion system.

RESULTS(1) The esophageal pH monitoring showed that median of percentage of pH < 4 at postprandial in HS and patients with GERD was 0.45% and 11.2%, respectively (P < 0.05). (2) Pressure of lower esophageal sphincter (LESP) significantly decreased after a test meal in GERD (P < 0.001) and in HS (P < 0.001). (3) The amplitude of post-LES relaxation related to swallow (post-LESRA) in GERD was much lower than in HS either during fasting or postprandial stage (P < 0.05). (4) The tension of crural diaphragm at resting (Dia-A0) in GERD was lower than in HS during fasting and postprandial stage(P < 0.05). (5) The tension of crural diaphragm at deep inspiration (dia-AM) in GERD and HS increased 3 or 4 times at pressure at gastroesophageal junction (GEJ). (6) The peristaltic amplitude of the distal esophagus in GERD were much lower than that in HS in both pre- and postprandial periods.

CONCLUSIONS(1) Impaired clearance of Post-LESRA and esophageal body, function of diaphragmatic crural play an important role in development of GERD. (2) The tension of crural diaphragm at deep inspiration can increase the pressure at GEJ.

Adolescent ; Adult ; Aged ; Diaphragm ; physiopathology ; Esophagogastric Junction ; physiopathology ; Esophagus ; physiopathology ; Gastroesophageal Reflux ; physiopathology ; Humans ; Hydrogen-Ion Concentration ; Manometry ; Middle Aged ; Peristalsis

OBJECTIVEIn the recent twenty years, the diaphragmatic contraction, relaxation functions and electric activity have been explored through electromyography (EMG) and transdiaphragmatic pressure (Pdi) determination. But these techniques required some complex and expensive instruments, so the diagnosis and treatment of children's diaphragmatic fatigue have not been well evaluated. The present study explored the diagnosis of children's diaphragmatic fatigue through measuring ribcage-abdomen motion and analyzed its asynchrony.

METHODSFifty-three children (male 37, female 16, and age rage from 1 months to 9 years) with respiratory rate > 30 breaths/min, heart rate > 110 beats/min, and respiratory dysfunction had asynchronized ribcage-abdomen motion showed by impedance respirograph (IRG). The authors observed whether ribcage-abdomen motion was synchronic and calculated M levels (staggered peak time/total duration of the breathing cycle). The ribcage and abdomen outputs were displayed on vertical (for rib cage) and horizontal (for abdomen) axes of X-Y instrument. In addition, the change of respiratory frequency and heart rate was observed and arterial blood-gas analysis was also performed.

RESULTS(1) M levels in one-dimensional IRG were positively correlated with alpha angle in two-dimensional IRG (r = 0.956, P < 0.001). Asynchronized respiratory motions could be divided into three types. type I showed completely contra-directional movements of respiration, M levels for (48.1 +/- 4.4)%, an irregularly clockwise loop in the two dimensional IRG, and alpha angle for (138.3 +/- 15.0) degrees. In type II, one dimensional IRG showed displaced peak of the chest and abdomen motion curves, M levels were (16.5 +/- 4.7)%, two dimensional IRG was displaced in a counterclockwise direction, and alpha angle was (55.3 +/- 10.8) degrees. In type III, abdominal motion curve of one dimensional IRG had double peaks, M levels were 0, two dimensional IRG was presented as 8-shaped double circles, alpha angle was (41.3 +/- 3.8) degrees; (2) pH levels in the patients with type I and type II diaphragmatic fatigue were significantly lower, and PCO(2) levels were significantly higher than those with type III or in the normal subjects (P < 0.001 for all), but there was no statistically significant difference between type III and the normal subjects (P > 0.05); (3) Both of respiratory rate and heart rate in type I, type II and type III were higher than those in the normal subjects (all P < 0.001), and the differences among the three types were significant (P < 0.001 for all); (4) Both M levels and alpha angle were negatively correlated with pH levels (r = -0.514, P < 0.001 and r = -0.497, P < 0.001), while positively correlated with PCO(2) levels (r = 0.672, P < 0.001 and r = 0.625, P = 0.01).

CONCLUSIONS(1) IRG can be reliably used to diagnose children's diaphragmatic fatigue. This technique is simple and easy to perform and non-invasive. It is therefore worthy of recommending for further clinical investigations. (2) According to the characteristics of IRG, diaphragmatic fatigue can be divided into three types. (3) The development of children's diaphragmatic fatigue has a series of characteristic changes. (4) To avoid the patients suffering from respiratory failure, it is the key time to adopt the policies of prevention and treatment when IRG shows signs of type III diaphragmatic fatigue.

Child ; Child, Preschool ; Diaphragm ; physiopathology ; Fatigue ; classification ; diagnosis ; Female ; Humans ; Infant ; Male ; Respiration ; Respiratory Function Tests ; methods

Positional asphyxia of restraint means that when an individual was limited in an abnormal body position, asphyxia would take place owing to the disorder of spontaneous respiratory function, and finally it lead to die. So, it belongs to a special type of the mechanical asphyxia. From the cases reported, we could found that it would take place in several conditions. Because the cases were not caused enough recognition, the study has been researched carefully only in recent years. Following the more cases reported, many experts of forensic medicine had investigated it on the mechanism of death and the standard of identification, but they could not reach to agreements. So, they have changed the directions of the researches, began to value the factors of risk and research how to avoid it. In the following text, the mechanism of death, factors of risk, preventive methods, standard of identification and prospecting of positional asphyxia of restraint were reviewed.
Alcoholic Intoxication/physiopathology* ; Animals ; Asphyxia/prevention & control* ; Cause of Death ; Diaphragm/physiopathology* ; Expert Testimony/standards* ; Forensic Medicine ; Humans ; Muscle Fatigue ; Posture/physiology* ; Respiratory Mechanics ; Restraint, Physical/adverse effects*

A reduction in diaphragm mobility has been identified in patients with chronic obstructive pulmonary disease (COPD) and has been associated with a decline in pulmonary function parameters. However, little information exists regarding the potential role of diaphragm mobility on hypercapnia in COPD. A new method of assessing the mobility of the diaphragm, using ultrasound, has recently been validated. The purpose of the present study was to investigate the relationship between diaphragm mobility and pulmonary function parameters, as well as that between arterial blood gas values and diaphragm mobility, in COPD patients. Thirty seven COPD patients were recruited for pulmonary function test, arterial blood gas analysis and diaphragm mobility using ultrasound to measure the craniocaudal displacement of the left branch of the portal vein. There were significant negative correlations between diaphragmatic mobility and PaCO2 (r = -0.373, P = 0.030). Diaphragmatic mobility correlated with airway obstruction (FEV1, r = 0.415, P = 0.011) and with ventilatory capacity (FVC, r = 0.302, P = 0.029; MVV, r = 0.481, P = 0.003). Diaphragmatic mobility also correlated significantly with pulmonary hyperinflation. No relationship was observed between diaphragm mobility and PaO2 (r = -0.028, P = 0.873). These findings support a possibility that the reduction in diaphragm mobility relates to hypercapnia in COPD patients.
Aged ; Airway Resistance/physiology ; Carbon Dioxide/blood/physiology ; Diaphragm/physiopathology/*ultrasonography ; Female ; Humans ; Hypercapnia/complications/*physiopathology ; Male ; Middle Aged ; Portal Vein ; Pulmonary Disease, Chronic Obstructive/complications/*physiopathology/ultrasonography ; Pulmonary Gas Exchange ; Respiratory Muscles/physiopathology

OBJECTIVETo investigate the effects of Ginkgo biloba extract (GbE) on the activities of energy metabolism enzymes and contraction capacity of diaphragm from type 2 diabetic rats.

METHODSForty SD male rats were randomly divided into normal control group (n=10) and model group (n=30). Type 2 diabetes models were induced by feeding with high-sucrose-high-fat diet and intraperitoneal injecting 25 mg/kg streptozotocin. 20 successful models were rearranged to two groups: diabetic group and GbE treatment group, 10 rats in each. Then the saline and 8 mg/(kg x d) of GbE were respectively intraperitoneal injected, once a day continuously for 8 weeks. Then diaphragm contractility was assessed using Peak twitch tension (Pt), Maximum tetanic tension (P0) and fatigue index (FI) in vitro diaphragm strip preparations. Cytochrome oxidase (CCO), lactate dehydrogenase (LDH) and succinate dehydrogenase (SDH) in diaphragm were detected and the varieties of diaphragm ultrastructure were observed.

RESULTSCompared with control group, Pt, P0 and FI in diabetic group decreased significantly (P < 0.01); the activity of CCO, LDH and SDH in the tissues was more obviously reduced than those in control group (P < 0.01). The ultrastructure in diabetic group under electron microscope indicated that diaphragm mitochondrions swelled and degenerated. The above changes were inhibited by GbE.

CONCLUSIONGbE can enhance contraction capacity of diaphragm from type 2 diabetic rats by increasing the aerobic oxidation capacity, glycolytic capacity and the function of respiratory chain.

Animals ; Diabetes Mellitus, Experimental ; physiopathology ; Diabetes Mellitus, Type 2 ; physiopathology ; Diaphragm ; drug effects ; physiopathology ; Drugs, Chinese Herbal ; pharmacology ; Ginkgo biloba ; chemistry ; Male ; Muscle Contraction ; drug effects ; Random Allocation ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo observe the effects of Bufei Jianpi Recipe (BJR) on the diaphragmatic neural discharge and the diaphragmatic muscle function in rats with chronic obstructive pulmonary disease (COPD).

METHODSRats were randomly divided into the normal control group, the model group, the high dose BJR group (9.68 g/kg x d(-1)), the medium dose BJR group (4.84 g/kg x d(-1)), the low dose BJR group (2.42 g/kg x d(-1)), and the aminophylline group (2.3 mg/kg x d(-1)). The stable phase COPD rat model was prepared using repeated smoke inhalations and bacterial infections. The high, medium, and low dose BJR and aminophylline was respectively administered to rats from the ninth week to the twentieth week. The sampling was taken. The lung function, diaphragmatic neural discharge time (Td), and diaphragmatic neural discharge interval (Tdi), diaphragmatic neural discharge range (Rd), diaphragmatic neural discharge area (Ad), expiratory time (Tex), inspiratory time (Tin), respiratory rate (RR), respiratory excursion (RE), respiratory area (RA), and diaphragmatic muscular tension and endurance were detected.

RESULTSCompared with the normal control group, the tidal volume (TV), peak expiratory flow (PEF), and 50% tidal volume expiratory flow (EF50) significantly decreased in the model group (P < 0.01). Td, Tdi, Tex, and Tin were significantly prolonged (P < 0. 05, P < 0.01). Ad, Rd, RR, RE, RA, diaphragmatic muscular tension and endurance significantly decreased (P < 0.05, P < 0.01). The ratio of type I and IIA diaphragmatic fibers significantly increased and type IIB significantly decreased (P < 0.01). The activity of ATP decreased and the activity of SDH increased (P < 0.01). The aforesaid indices were improved to different degrees in BJR groups, especially in the high dose BJR group and the medium dose BJR group (P < 0.05, P < 0.01).

CONCLUSIONSBJR could significantly improve the diaphragmatic neural discharge and the diaphragmatic muscle function. Its efficacy was better than that of aminophylline.

Aminophylline ; pharmacology ; Animals ; Diaphragm ; drug effects ; physiopathology ; Disease Models, Animal ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Male ; Phrenic Nerve ; drug effects ; physiopathology ; Phytotherapy ; Pulmonary Disease, Chronic Obstructive ; drug therapy ; physiopathology ; Rats