Potential of serum procalcitonin in predicting bacterial exacerbation and guiding antibiotic administration in severe COPD exacerbations: a systematic review and meta-analysis.

Background: The value of procalcitonin (PCT) in the diagnosis of bacterial infections and for determining antibiotic usage among patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD) is currently unclear. Methods: We systematically reviewed the literature and selected studies that evaluated PCT as a biomarker for predicting bacterial infection and compared PCT-based protocols to determine its application in the initiation or discontinuation of antibiotics. Guidance for systematic reviews from Cochrane and the GRADE were followed to perform this study. Data were pooled and analyzed by using a random-effects or a fixed-effects model based on the heterogeneity. Results: The pooled sensitivity and specificity of PCT in diagnosing respiratory bacterial infections were 0.60 and 0.76, respectively, with the area under the summary receiver operating characteristic curve of 0.77. Subgroup analysis showed that the sensitivity and specificity of PCT for patients in ICU were 0.48 and 0.69, respectively. PCT-based protocols decreased antibiotic prescription (relative risk = 0.66, 95% CI: 0.62-0.71) and total antibiotic exposure (mean difference = -2.60, 95% CI: -4.48-0.72), without affecting clinical outcomes such as treatment failure, length of hospitalization and rates of re-exacerbation or overall mortality. Conclusions: PCT has a moderate ability to distinguish bacterial respiratory infection in patients with AECOPD. PCT-guided algorithm can reduce unnecessary administration of antibiotics without increasing adverse outcomes. However, for patients requiring admission in the ICU, PCT may have a poor diagnostic value, and the PCT-guided algorithm may not effectively and safely reduce the antibiotic exposure.

Validation of the Nox-T3 Portable Monitor for Diagnosis of Obstructive Sleep Apnea in Patients With Chronic Obstructive Pulmonary Disease.

STUDY OBJECTIVES: Clinical practice guidelines recommend polysomnography (PSG) for diagnosis of obstructive sleep apnea (OSA) in patients with major comorbidities. We evaluated home sleep apnea testing (HSAT) using a type 3 portable monitor (PM, Nox-T3, Nox Medical, Reykjavik, Iceland) to diagnose OSA in adults with chronic obstructive pulmonary disease (COPD). METHODS: Ninety adults with COPD (89.0% males, mean ± standard deviation age 66.5 ± 7.8 years, body mass index 27.5 ± 5.8 kg/m2, forced expiratory volume in the first second/forced vital capacity [FEV1/ FVC] 53.5 ± 12.4%, FEV1 54.0 ± 18.4% predicted) underwent unattended HSAT followed by an in-laboratory PSG with simultaneous PM recording. RESULTS: Scoring hypopneas with a ≥ 4% oxygen desaturation, the apnea-hypopnea index (AHI) was 16.7 ± 20.6 events/h on HSAT, 20.0 ± 23.3 events/h on in-laboratory PM, and 21.2 ± 26.2 events/h on PSG (P < .0001). Bland-Altman analysis of AHI on HSAT versus PSG showed a mean difference (95% confidence interval) of -5.08 (-7.73, -2.42) events/h (P = .0003) and limits of agreement (± 2 standard deviations) of -30.00 to 19.85 events/h; HSAT underestimated AHI to a greater extent for more severe values (rho = -.529, P < .0001). Using an AHI ≥ 5 events/h to diagnose OSA, HSAT had 95% sensitivity, 78% specificity, 88% positive predictive value, and 89% negative predictive value compared to PSG. Mean oxygen saturation was 93.2 ± 3.7% on PSG, 91.0 ± 3.3% on in-laboratory PM, and 90.8 ± 4.0% on HSAT (P < .0001). Percentage time oxygen saturation ≤ 88% was 17.9 ± 26.4% on HSAT, 17.4 ± 25.5% on in-laboratory PM, and 10.0 ± 21.1% on PSG (P < .0001). CONCLUSIONS: The Nox-T3 PM can be used to diagnose OSA in patients with COPD but, most likely due to differences among pulse oximeters, a greater number of patients with COPD and without OSA qualified for nocturnal oxygen treatment using this PM than PSG.

Transcriptionally Active Lung Microbiome and Its Association with Bacterial Biomass and Host Inflammatory Status.

Alteration of the lung microbiome has been observed in several respiratory tract diseases. However, most previous studies were based on 16S ribosomal RNA and shotgun metagenome sequencing; the viability and functional activity of the microbiome, as well as its interaction with host immune systems, have not been well studied. To characterize the active lung microbiome and its associations with host immune response and clinical features, we applied metatranscriptome sequencing to bronchoalveolar lavage fluid (BALF) samples from 25 patients with chronic obstructive pulmonary disease (COPD) and from nine control cases without known pulmonary disease. Community structure analyses revealed three distinct microbial compositions, which were significantly correlated with bacterial biomass, human Th17 immune response, and COPD exacerbation frequency. Specifically, samples with transcriptionally active Streptococcus, Rothia, or Pseudomonas had bacterial loads 16 times higher than samples enriched for Escherichia and Ralstonia. These high-bacterial-load samples also tended to undergo a stronger Th17 immune response. Furthermore, an increased proportion of lymphocytes was found in samples with active Pseudomonas. In addition, COPD patients with active Streptococcus or Rothia infections tended to have lower rates of exacerbations than patients with active Pseudomonas and patients with lower bacterial biomass. Our results support the idea of a stratified structure of the active lung microbiome and a significant host-microbe interaction. We speculate that diverse lung microbiomes exist in the population and that their presence and activities could either influence or reflect different aspects of lung health. IMPORTANCE Recent studies of the microbiome proposed that resident microbes play a beneficial role in maintaining human health. Although lower respiratory tract disease is a leading cause of sickness and mortality, how the lung microbiome interacts with human health remains largely unknown. Here we assessed the association between the lung microbiome and host gene expression, cytokine concentration, and over 20 clinical features. Intriguingly, we found a stratified structure of the active lung microbiome which was significantly associated with bacterial biomass, lymphocyte proportion, human Th17 immune response, and COPD exacerbation frequency. These observations suggest that the microbiome plays a significant role in lung homeostasis. Not only microbial composition but also active functional elements and host immunity characteristics differed among different individuals. Such diversity may partially account for the variation in susceptibility to particular diseases.

Common Variable Immunodeficiency with Genetic Defects Identified by Whole Exome Sequencing.

Common variable immunodeficiency (CVID) belongs to the primary immunodeficiency disorders (PIDs), presenting a profound heterogeneity in phenotype and genotype, with monogenic or complex causes. Recurrent respiratory infections are the most common clinical manifestations. CVID patients can also develop various autoimmune and lymphoproliferative complications. Genetic testing such as whole exome sequencing (WES) can be utilized to investigate likely genetic defects, helping for better clinical management. We described the clinical phenotypes of three sporadic cases of CVID, who developed recurrent respiratory infections with different autoimmune and lymphoproliferative complications. WES was applied to screen disease-causing or disease-associated mutations. Two patients were identified to have monogenic disorders, with compound heterozygous mutations in LRBA for one patient and a frameshift insertion in NFKB1 for another. The third patient was identified to be a complex form of CVID. Two novel mutations were identified, respectively, in LRBA and NFKB1. A combination of clinical and genetic diagnosis can be more extensively utilized in the clinical practice due to the complexity and heterogeneity of CVID.

Metabolic profiles in community-acquired pneumonia: developing assessment tools for disease severity.

BACKGROUND: This study aimed to determine whether community-acquired pneumonia (CAP) had a metabolic profile and whether this profile can be used for disease severity assessment. METHODS: A total of 175 individuals including 119 CAP patients and 56 controls were enrolled and divided into two cohorts. Serum samples from a discovery cohort (n = 102, including 38 non-severe CAP, 30 severe CAP, and 34 age and sex-matched controls) were determined by untargeted ultra-high-performance liquid chromatography with tandem mass spectrometry (LC-MS/MS)-based metabolomics. Selected differential metabolites between CAP patients versus controls, and between the severe CAP group versus non-severe CAP group, were confirmed by targeted mass spectrometry assays in a validation cohort (n = 73, including 32 non-severe CAP, 19 severe CAP and 22 controls). Pearson's correlation analysis was performed to assess relationships between the identified metabolites and clinical severity of CAP. The area under the curve (AUC), sensitivity and specificity of the metabolites for predicting the severity of CAP were also investigated. RESULTS: The metabolic signature was markedly different between CAP patients and controls. Fifteen metabolites were found to be significantly dysregulated in CAP patients, which were mainly mapped to the metabolic pathways of sphingolipid, arginine, pyruvate and inositol phosphate. The alternation trends of five metabolites among the three groups including sphinganine, p-Cresol sulfate, dehydroepiandrosterone sulfate (DHEA-S), lactate and L-arginine in the validation cohort were consistent with those in the discovery cohort. Significantly lower concentrations of sphinganine, p-Cresol sulfate and DHEA-S were observed in CAP patients than in controls (p < 0.05). Serum lactate and sphinganine levels were positively correlated with confusion, urea level, respiratory rate, blood pressure, and age > 65 years (CURB-65), pneumonia severity index (PSI) and Acute Physiology and Chronic Health Evaluation II (APACHE II) scores, while DHEA-S inversely correlated with the three scoring systems. Combining lactate, sphinganine and DHEA-S as a metabolite panel for discriminating severe CAP from non-severe CAP exhibited a better AUC of 0.911 (95% confidence interval 0.825-0.998) than CURB-65, PSI and APACHE II scores. CONCLUSIONS: This study demonstrates that serum metabolomics approaches based on the LC-MS/MS platform can be applied as a tool to reveal metabolic changes during CAP and establish a metabolite signature related to disease severity. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03093220 . Registered retrospectively on 28 March 2017.

Evaluation of symptoms and risks in stable chronic obstructive pulmonary disease patients with radiographic bronchiectasis.

OBJECTIVE: To investigate the presence of previously undiagnosed radiographic bronchiectasis in stable chronic obstructive pulmonary disease (COPD) patients using high resolution computed tomography (HRCT) and to evaluate the effect of radiographic bronchiectasis on the symptoms and risks in stable COPD patients. METHODS: From May 2012 to April 2014, there were 347 patients enrolled in COPD database. Data describing the general conditions, the frequency of acute exacerbations the year before, COPD assessment test, modified medical research council (mMRC) score, spirometric classification, and HRCT were collected. COPD patients were classified into two groups: COPD with bronchiectasis and COPD without bronchiectasis. The clinical characteristics of both groups were compared. RESULTS: Bronchiectasis was presented in 18.4% (n = 64). The proportion of smokers, smoking index, and forced expiratory volume in 1 second predicted value were 62.5%, 27.3 ± 13.2, 48.2 ± 26.4, respectively, in the bronchiectasis group, which were lower than those of the group without bronchiectasis (82.0%, 32.6 ± 17.6, and 57.9 ± 18.8) (P < 0.05). Complications, COPD assessment test (CAT) and the rate of CAT ≥ 10 in the bronchiectasis group were 2.8 ± 1.7,13.6 ± 7.4 and 26.6%, respectively, which were higher than those of the group without bronchiectasis (2.3 ± 1.5,11.3 ± 6.0, and 11.7%) (P < 0.05). The proportion of type D (high-risk more-symptoms) in the bronchiectasis group was 50.0%; it was significantly higher than that of 35.7% in the group without bronchiectasis (P < 0.05). CONCLUSIONS: COPD with bronchiectasis is associated with more complications, symptoms, and risks. More attention should be paid to the treatment of COPD with bronchiectasis to reduce the frequency of exacerbation and improve the health status.

[Investigation of Lung Cancer Patients Complicated with Chronic Obstructive Pulmonary Disease in Thoracic Surgical Department].

BACKGROUND: Lung cancer is an important complication of chronic obstructive pulmonary disease (COPD), and even significantly affects the prognosis of patients with COPD. COPD also affects the postoperative complications and recurrence in patients with lung cancer. This study aims to investigate lung cancer patients complicated with COPD in thoracic surgical department. METHODS: All medical records of lung cancer patients discharged from the Department of Thoracic Surgery of People's Hospital, Peking University during January 2015 and December 2015 were reviewed, including gender, age, tobacco smoke history, harmful occupational exposure, clinic symptom, chest computed tomography (CT) scanning, postoperative pathology result report, discharged diagnosis and spirometry [All patients underwent pulmonary function test are received bronchial dilation test if the based predicted value of forced expiratory volume in one second (FEV1) <70%]. RESULTS: A full set of lung function test was measured in 703 lung cancer patients. Bronchial dilation test was finished in 67 patients. 62 (92.5%) patients were diagnosed as COPD. 677 cases with lung cancer were received surgery. Bronchial dilation test was measured in 42 cases. Of them 38 (92.7%) patients were diagnosed as COPD. It was found that the patients with lung cancer and COPD was more frequent in males, elders (≥65 yr), smokers, non-adenocarcinoma patients than those of patients without COPD (P<0.05). The males and the elders (≥65 yr) were more likely to suffer from COPD (OR: 2.374-2.807, 95%CI: 1.101-7.157)(P<0.05). Only 3 patients (4.3‰) were diagnosed as COPD and received standard treatment before admission. And only 5 patients (7.1‰) were diagnosed as COPD as discharged. CONCLUSIONS: The routine pulmonary function as well as bronchial dilation test are helpful for screening the patients with COPD. At present, the diagnosis and treatment of lung cancer combined with COPD is a serious problem, which needs to be paid attention to by thoracic surgeons and to join hands with physicians in order to improve the diagnosis level of COPD.

Comparison of symptom and risk assessment methods among patients with chronic obstructive pulmonary disease.

BACKGROUND: The global strategy for the diagnosis, management and prevention of chronic obstructive pulmonary disease (COPD) guidelines classify patients into four groups according to the number of symptoms and the level of future risk of acute exacerbation COPD (AECOPD). This study aimed to compare the results of different methods used in diagnosis of COPD and evaluate the accuracy of the assessment methods in guiding clinical practice. METHODS: A survey was conducted of 194 COPD outpatients between March and September 2012. Demographic characteristics, the number of exacerbations the patient has had within the previous 12 months, COPD assessment test (CAT), Modified British Medical Research Council (mMRC) scale, and results of the lung function tests were recorded. RESULTS: Of the 194 patients assessed, 21 had a CAT score ≥10 and an mMRC grade ≤1, 13 had a CAT score <10 and an mMRC grade ≥2. A predicted forced expiratory volume in one second (FEV1%) of <50% with less than two acute exacerbations was observed in 39 patients, while a predicted FEV1% of ≥50% was noted in 20 patients with two or more acute exacerbations. The sensitivity of a predicted FEV1% <50% in predicting the risk of AECOPD in the future was 80.9%, while that in the real number of AECOPD events recorded was 62.8%, the difference being statistically significant (P = 0.004). The sensitivity of CAT in predicting the severity of symptoms was 90%, while that of mMRC was 83.8%, and the difference was not statistically significant. CONCLUSIONS: The COPD assessment method recommended by the global initiative for chronic obstructive pulmonary disease (GOLD) 2011 is complicated and should be simplified. CAT is more comprehensive and accurate than mMRC. The lung function classification is a better tool for predicting the risk of AECOPD in the future, and the number of AECOPD can be referred to when required.

[Interventional effects of different management programs on the outcomes of stable chronic obstructive pulmonary disease patients].

OBJECTIVE: To evaluate the interventional effects of different management programs on the outcomes of stable chronic obstructive pulmonary disease (COPD) patients. METHODS: Systemic education, follow-up and control groups were divided according to the frequency of follow-ups and the profile of participating in education. A total of 157 patients were enrolled into the COPD database from May 2002 to May 2010. They were interviewed face-to-face at our department. The investigation contained general conditions, the frequency of acute exacerbations (AE) the previous year, COPD Assessment Test (CAT), Modified British Medical Research Council Dyspnea Scale (mMRC) and spirometric classification. A combined assessment was conducted. RESULTS: The frequency of AE and rate of AE < once the previous year in systemic education group was 0.9 ± 1.1 and 71.2%, 1.0 ± 0.8 and 68.6% in follow-up group and 1.4 ± 1.1 and 44.4% in control group. And the frequency of AE in systemic education and follow-up groups was significantly less than that in control group (P < 0.05). Rate of AE < once in systemic education and follow-up groups was significantly higher than that in control group (P < 0.01). CAT and rate of CAT ≤ 20 in systemic education, follow-up and control groups were 10.0 ± 5.0 and 96.2%, 11.1 ± 6.0 and 88.2%, 15.3 ± 6.8 and 64.8% respectively. CAT in systemic education and follow-up groups was significantly lower than that in control group (P < 0.01). Rate of CAT ≤ 20 in systemic education and follow-up groups was significantly higher than that in control group (P < 0.01). mMRC in systemic education, follow-up and control groups was 1.5 ± 0.8, 1.6 ± 0.9 and 2.1 ± 1.0 respectively. mMRC in systemic education and follow-up groups was significantly lower than that in control group (P < 0.05). Combined assessment showed that no significant difference existed in Types A and B among three groups (P > 0.05). Type C in the systemic education group was significantly higher than that of the control (P < 0.05). Type D in the systemic education and follow-up groups was significantly lower than that of the control (P < 0.01). CONCLUSION: Long-term systemic education and follow-up management program can reduce the frequency of AE of COPD effectively and improve the health status of COPD patients.

[Evaluation of chronic obstructive pulmonary disease screening in a high risk population].

OBJECTIVE: To investigate the results of spirometry testing used in the screening of COPD from at risk populations. METHODS: A survey of the population aged over 40 years with any of chronic cough and sputum, dyspnea, heavy tobacco smoke was performed, using a questionnaire on clinical characteristics of COPD. Spirometry and chest X ray examination were performed. Different screening methods were compared for sensitivity and specificity for COPD diagnosis. RESULTS: Of 241 surveyed persons, 156 were diagnosed as having COPD, among whom 126 cases were firstly diagnosed. Among all surveyed persons, 87 (36. 1%) cases had mild and moderate COPD, while 69 (28. 6%) had severe and very severe disease. The sensitivity and specificity for diagnosis of COPD of shortness of breath were 61.5% and 61.2% respectively. Combination of respiratory symptoms and risk factors improved the screening power. More than 40 years of age combined with any of heavy smoking, chronic cough and sputum, or shortness of breath, improved the sensitivity to more than 90 percent. CONCLUSIONS: Spirometry test screening of the at risk population can effectively improve early diagnosis of COPD.

[Respiration control dysfunction and the relationship to sleep-disordered breathing in patients with chronic obstructive pulmonary disease].

OBJECTIVE: To analyze the polysomnographic (PSG) features of sleep apnea hypopnea syndrome (SAHS) in patients with chronic obstructive pulmonary disease (COPD), and to define the association between SAHS and respiratory control disorder. METHODS: Three hundred patients with stable COPD were screened for SAHS using questionnaire, Epworth sleep scale (ESS) and home pulse oximeter testing. Those with ESS > or = 10 or oxygen desaturation over 3% more than 5 times per hour sleep were under further PSG testing. The PSG features were compared between COPD patients with apnea hypopnea index (AHI) > 10 and 118 SAHS patients with normal lung function. The two groups were matched for age, body mass index (BMI) and AHI. Among them 22 with COPD and AHI > or = 10 were tested for the chemo-responsiveness to isocapnic hypoxia and hypercapnia. RESULTS: Among the 300 patients with stable COPD, 79 had AHI over 10, meeting the diagnostic criteria of overlap syndrome (OS). Analysis of the polysomnography found that 32 cases (40%) with OS had more hypoventilation lasting over 1 min during sleep. Compared to patients with SAHS only, OS patients had higher percentage of hypopnea index over AHI [(69 +/- 30)% vs (52 +/- 31)%] and a higher percentage of total hypopnea time over total time of sleep apnea and hypopnea [(15 +/- 12)% vs (12 +/- 10)%]. OS patients also had lower hypoxic [(-0.11 +/- 0.05) vs (-0.35 +/- 0.24) L.min(-1).%(-1)] and hypercapnic responses [(1.1 +/- 0.8) vs (1.6 +/- 0.8) L.min(-1).mm Hg(-1) (1 mm Hg = 0.133 kPa)]. CONCLUSION: Patients with both COPD and SAHS had more episodes of hypopnea and hypoventilation during sleep, and had depressed chemo-responsiveness to hypoxia during wakefulness.

[Roles of the central nucleus of amygdala in the cardiovascular response elicited by the paraventricular nucleus of hypothalamus].

OBJECTIVE: To investigate the cardiovascular responses induced by activation of the paraventricular nucleus of hypothalamus (PVN) and the roles of the central nucleus of amygdala (CeA) on this effect. METHODS: The PVN was activated by microinjection of L-glutamate or electrical stimulation. The CeA was injected with L-glutamate or Kainic acid (KA). The femoral arterial pressure, mean arterial pressure (MAP), electrocardiogram (ECG) and heart rate (HR) of the male SD rats were recorded when the PVN was electrically stimulated. RESULT: The blood pressure increased when the PVN was activated either by electrical current or by L-glutamate. The blood pressure increased for (10.27+/-1.80)mmHg and the change of heart rate was -10.66 +/- 8.11 beat/min after L-Glu (100 nl) was injected into the ipsilateral CeA. The pressor response of PVN stimulation could still be evoked by electrical stimulation of (13.78 +/- 3.18)mmHg 10 min after kainic acid (100 nl) was injected into the ipsilateral CeA. But this pressor response decreased of 6.57 mmHg compared to that before injection of KA (P <0.05). The locations of the electrode tips and termination of the injector tracts were identified according to the atlas after the recording. CONCLUSION: Stimulating the PVN elicits pressor response in rats. The CeA mediates partly the pressor response elicited by activation of the PVN.

[Role of dorsal column in pathway of hypotensive effect of the somatic afferent inputs].

OBJECTIVE: To investigate the role of the dorsal column (DC) in the inhibitory effect of somatic afferent inputs on the central pressor response. METHODS: The femoral arterial pressure, mean arterial pressure (MAP), electrocardiogram (ECG) and heart rate (HR) of the male SD rats were recorded when the hypothalamic paraventricular nucleus (PVN) was electrically stimulated with or without destruction of DC. The inhibitory effect of the deep peroneal nerve (DPN) on the pressor response induced by stimulation of PVN was observed 20 min or 5 d after ipsilateral DC destruction. RESULTS: Stimulating DPN inhibited the pressor response elicited by electrical stimulation of PVN with an inhibitory rate of 43.29%. Twenty minutes after destroying the right DC, stimulation of the right or left DPN could inhibit the pressor response with an inhibitory rate of 38.64% and 39.97%, respectively (P>0.05); five days later the inhibitory rates remained as 33.87% and 36.86% respectively (P>0.05). The pain responses of both hindlimbs in the rats with the right DC destroyed showed no significant difference compared with the intact rats. CONCLUSION: DC is not involved in the inhibitory effect of DPN on the pressor response induced by PVN stimulation.

[Study on matrix metalloproteinase 1, 9, 12 polymorphisms and susceptibility to chronic obstructive pulmonary disease among Han nationality in northern China].

OBJECTIVE: To study the association between the functional polymorphism of matrix metalloproteinases (MMPs) and the development of chronic obstructive pulmonary disease (COPD). METHODS: 147 COPD patients and 120 healthy smoking controls were selected. Spirometry and chest X-rays had been taken. Questionnaires including sex, age, smoking history, occupational exposure were completed. MMP-9 (-1562 C/T), MMP-1(-1607 1G/2G), MMP-12 (-82 A/G), MMP-12(-357 Asn/ Ser) alleles were determined using PCR-RFLP method. Independent samples T test analysis was carried out to compare patients' age, smoking index, FEV1 /FVC, FEV1 % pred with that of healthy controlled group. The frequencies of genotypes and alleles between groups were analyzed by chi-square tests and multilogistic regression. RESULTS: MMP12 Asn/Asn, CT/AsnAsn were risk factors for smoking-induced COPD. The ORs were 2.361 (95% CI: 1.369-4.017) and 2.433(95% CI: 1.159-5.342) respectively while CC/1G1G/ SerSer seemed to be a protective factor for smoking-induced COPD, with OR as 0.457 and 95% CI as 0.231-0.911. CONCLUSION: Asn/Asn, CT/AsnAsn might be susceptible genotypes while CC/GG/SerSer might serve as protective genotype.

[Microsomal epoxide hydrolase gene polymorphism and susceptibility to chronic obstructive pulmonary disease in Han nationality of North China].

OBJECTIVE: We investigated whether polymorphism in gene for microsomal epoxide hydrolase (mEH) has any bearing on individual susceptibility to the development of chronic obstructive pulmonary disease. METHOD: The genotypes of 55 patients with COPD and 52 healthy smoking control subjects were tested with polymerase chain reaction followed by restriction fragment length polymorphism for mEH gene. RESULT: The frequency of polymorphic genotypes of mEH showed no difference between the COPD group and the control group. In COPD group mEH exon 3 homozygous wild-type, heterozygote and homozygous mutant was 27.3%, 27.3% and 45.5% respectively and exon 4 homozygous wild-type, heterozygote and homozygous mutant was 72.7%, 18.2% and 9.1% respectively. CONCLUSION: Genetic polymorphism in mEH is not associated with development of COPD in Han nationality of North China.

[The role of dorsomedial hypothalamic nucleus in the cardiovascular responses induced by habenular nucleus stimulation and inhibitory effect of deep peroneal nerve].

AIM: To explore whether dorsomedial hypothalamic nucleus (DMH) is involved in the cardiovascular responses induced by habenular nucleus (Hb) stimulation and inhibitory effect of deep peroneal nerve (DPN) stimulation on above responses or not and to analysis transmitter mechanism. METHODS: Experiments were performed on white male rabbits anesthetised with chloralose and urethan. Experimental data were collected by means of stimulating Hb and DPN, recording arterial blood pressure and ectal electrocardiogram (EECG) and microinjecting transmitter blocker. RESULTS: Prominent pressor and ischemic EECG segment changes were elicited by Hb stimulation (P < 0.01) Microinjecting kynurenic acid into ipsilateral DMH had partial blocking effect on pressor and ischemic EECG-ST segment changes induced by Hb stimulation (P < 0.01). Stimulation of bilateral DPN prominently inhibited the pressor and ischemic EECG-ST changes induced by Hb stimulation (P < 0.01, P < 0.05). Microinjecting naloxone into ipsilateral DMH decreased the inhibitory effect of DPN stimulation on above cardiovascular responses elicited by Hb stimulation (P < 0.01, P < 0.05). CONCLUSION: Glutamic acid receptor in DMH is involved in pressor and ischemic changes induced by Hb stimulation. DMH and opiate peptide receptors in DMH are involved in the inhibitory effect of DPN stimulation on pressor and ischemic changes induced by Hb stimulation.