ObjectiveTo investigate the pathogens and prognostic factors of AIDS-associated severe pneumonia. MethodsClinical data were collected from 95 patients with AIDS-associated severe pneumonia admitted to Guangzhou No. 8 People' s Hospital from January 2005 to December 2008. The pathogens of pulmonary infections were investigated. Univariate analysis and multivariate logistic regression analysis were performed to study the relationships between the outcome and influencing factors. Results The most prevalent pathogen was Pneumocystis jirovecii (64/95, 67.4％ ), followed by bacteria (61/95, 64.2％ ),fungi ( 50/95, 52. 6％ ), mycobacterium tuberculosis ( 27/95, 28. 4％ ) and cytomegalovirus ( CMV ) (25/95, 26.3％ ). Among 95 cases, monocontamination was detected in 15 cases ( 15.8％ ), while mixed infection in 80 cases (84. 2％ ). Logistic regression analysis showed that mechanical ventilation, higher serum lactic dehydrogenase (LDH) level and severe underlying diseases were risk factors for the death of AIDS-associated severe pneumonia, and higher serum albumin level was the protective factor. Conclusion Pneumocystis jirovecii, bacteria and fungi are the main pathogens for AIDS-associated severe pneumonia, and mixed infection is popular.

Objective To study the pathogens and drug resistance profiles of pulmonary infection in patients with AIDS. Methods The pathogens and their drug susceptibility of pulmonary infection diagnosed by fibrobronchescopy-induced brunchoalveolar lavage fluid (BAI.F) culture and/or transbronchial biopsy in 116 AIDS cases were analyzed. Results Monopathogenic infection in lungs were detected in 18 cases(15.5%) and mixed infection in 98 cases ( 84.5%). Of the 116 cases, bacteria were present in 91 patients, fungi in 62, tubercle bacillus in 49, pneumocystis jiroveci in 29, and cytomegalovirus in 11.Ninety-five bacterial strains were isolated from BALF, mainly including Streptococci (34), coagulase negative Staphylococcus (20), Klebsiella pneumoniae (10) and Escherichia (7). The isolated bacteria were resistant to β-lactam, macrolides, quinolones and aminoglycosides, of which were 14 methicillin-resistant Streptococci (MRS) strains and 12 extended spectrum β-lactamases (ESBL) strains. Sixty-eight fungal strains were isolated, including 36 Candida mycodermas, 19 Penicilliums, 6 Aspergilli and 5 Mold fungi;they were sensitive to amphotericin B but resistant to fluconazol (5.6% -50. 0% ) and itraconazole( 10. 5%-60. 0% ). Conclusion Pneumonia in AIDS patients are usually caused by multiple pathogens,predominantly consisting of multiresistant bacteria and fungi. Therefore, antibiotics should be rationally chosen according to drug susceptibility test.

Objective To investigate gene polymorphisms of drug targets and mutations associated with drug resistance in Pneumocystis jiroveci (P.jiroveci) isolates.Methods Among 148 samples isolated from human immunodeficiency virus (HIV)infected patients with pneumonia in Guangdong,mitochondrid larg subunit rRNA (mtLSUrRNA) gene was amplified from 51 samples.Dihydropteroate synthase (DHPS),dihydrofolate reductase (DHFR) and Cytochrome b (CYB) genes of P.jiroveci were detected by gene sequencing,and compared with the reference sequences in GenBank to evaluate gene polymorphisms.Results P.jirovecii DHPS,DHFR and CYB genes were all successfully amplified from 51 samples.For DHPS gene,48 (94.1％) were wild-type and 3 (5.9％) had gene mutation associated with drug resistance.For DHFR gene,30 were wild-type,and 21 had a synonymous mutation at position 312,and 1 nonsynonymous mutation at position 188.There were no mutations associated with drug resistance.For CYB gene,polymorphisms of were detected at 5 sites,4 of which were synonymous mutations,1 was non-synonymous mutation.No mutation associated with drug resistance was found.Based on the gene polymorphism of CYB6,the strains can be classified into 6 genotypes,and 2 were first detected,including 25 CYB1,13 CYB2,2 CYB5,4 CYB8,as well as newly detected 4 CYB10 and 3 CYB11 strains.Conclusions The mutations associated with drug resistance in P.jiroveci isolates in Guangdong remain uncommon.CYB gene shows gene polymorphisms and can be selected as one of targeted genes for multilocus sequence typing.

Objective To evaluate the effect of penehyclidine hydrochloride on the damage to the non-ventilated lung in the pediatric patients undergoing one-lung ventilation (OLV).Methods One hundred and twenty pediatric patients of both sexes,aged 2-6 yr,with body mass index of 17-24 kg/m2,of American Society of Anesthesiologists physical status Ⅰ or lⅡ and New York Heart Association class Ⅰ or Ⅱ,undergoing elective lobectomy performed via video-assisted thoracoscope,were randomly divided into 2 groups (n=60 each) using a random number table:control group (group C) and penehyclidine hydrochloride group (group P).At 10 rmin before anesthesia induction,penehyclidine hydrochloride 0.05 mg/kg was injected intravenously in group P,and the equal volume of normal saline was given in group C.At 5 min after drug intervention (T0),immediately after onset of OLV (T1),at 60 min of OLV (T2),immediately after the end of OLV (T3),at the end of surgery (T4),and at 24 h after surgery (T5),venous blood samples were collected for determination of serum tumor necrosis factor-alpha (TNF-o),interleukin-6 (IL-6) and IL-8 concentrations by enzyme-linked immunosorbent assay.The specimens of normal lung tissues around the lung lobe to be resected were obtained at T1 and T3 for determination of the injured alveolus count (with a light microscope) and cell apoptosis (using TUNEL) and for examination of the ultrastructure of epithelial cells (with a transmission electron microscope).The injured alveolus rate (IAR) and apoptosis index (AI) were calculated.Results Compared to the value at T0,the IAR and AI were significantly increased at T3,the serum TNF-α,IL-6 and IL-8 concentrations were significantly increased at T2-5 (P＜0.05),and the pathological changes were obvious in the two groups.Compared to group C,the IAR and AI were significantly decreased at T3,the serum TNF-α,IL-6 and IL-8 concentrations were significantly decreased at T2-5 (P＜0.05),and the pathological changes were significantly reduced in group P.Conclusion Penehyclidine hydrochloride can attenuate the damage to the non-ventilated lung in the pediatric patients undergoing OLV,and the mechanism is probably related to inhibition of systemic inflammatory responses and cell apoptosis in lung tissues.

Objective To study the clinical characteristics, diagnostic methods and therapeutic efficacy of pneumocystis pneumonia (PCP) in patients with acquired immunodeficiency syndrome (AIDS). Methods Sixty-nine AIDS cases of PCP were diagnosed according to the criteria of USA Centers for Disease Control and Prevention revised in 1993. The clinical symptoms and signs of the patients were observed. The peripheral blood lymphocyte counts, blood gas analysis and bronchoalveolar lavage fluid (BALF) were checked and transbronchoscopic lung biopsy was performed. Results All studied patients were in the late stage of AIDS. The main clinical manifestations included fever (100.0%), cough (97.1%), and dyspnea (92.80%). Pulmonary rales could be heard in 42 cases (60.9% ). Peripheral CD4+ T lymphocyte counts ranged from 1 × 106 -88 × 106/L. Fifty-two cases (75.4% ) had low arterial partial pressure of oxygen value of less than 10.7 kPa (1 kPa = 7.5 mm Hg). Sixty-one cases (88.4 %) had elevated serum lactate dehydrogenase (LDH) level. Bilateral diffused interstitial change (46.4%) and ground-glass shadow (29.0%) were the most common abnormal chest radiological findings. Pneumocystis organisms were detected in the BALF from 2 patients and in the transbronchial biopsy (TBB) tissue from 35 patients. All patients were treated with compound sulfamethoxazole. Thirty-three were treated with corticosteroid simultaneously and 27 were assisted with mechanical ventilation. Fifty patients recovered or got improved, eleven died, and eight left hospital because of deteriorated condition. Conclusions When an AIDS patient represents with fever, cough, dyspnea, hypoxemia, elevated serum I.DH level, CD4+ T lymphocyte count below 100 × 106/L, and interstitial pneumonia or ground-glass shadow in chest images, the diagnosis of PCP could be made presumptively. It is difficult to make a nosogenic diagnosis of PCP, but TBB considerably increases the positive rate of pneumocystis. Compound sulfamethoxazole is recommended as the first selected drug. In severe cases, corticosteroid and assisted mechanical ventilation combined with compound sulfamethoxazole could remarkably improve the prognosis of PCP.

Objective To investigate the effect of glucocorticosteroids on pulmonary oxygenation function in severe acute respiratory syndrome(SARS)patients.Methods Two hundred and twenty-five SARS patients in 2003 were analyzed retrospectively.Oxygenation index(OI)was considered as the marker of glucocorticosteroids therapeutic effects.The criteria of effectiveness was that OI increased 20%or more than pre-treatment.The therapeutic effects of glueocorticosteroids were analyzed by analysis of variance and chi-square test.Results Glucocorticosteroids were used in 59.6%(134/225)of SARS cases.The average OI before and after glucocorticosteroids intravenous treatment was 237.08 mm Hg and 335.08 mm Hg,respectively.The average OI increased 110.26 mm Hg(46.4%)after treatment.In 96 SARS patients whose blood gas analysis results were available,85 cases(88.5%)had administrative indication.The average OI increased 103.14 mm Hg(44.4%),which was lower than 190.91 mm Hg(66.8 0A)in patients without administrative indication.There was no significant difference between these two groups of patients.The OI difference before and after glueocorticosteroids treatment was decreased with the increasing OI before treatment,the increase was minimum in patients with OI≥300 mm Hg.Conclusions The SARS patients could obtain pulmonary symptoms and function improvements with appropriate glucoconicosteroids treatment,especially for those who are in accord with acute lung injure or acute respiratory distress syndrome,and OI less than 300 mm Hg before treatment.

Objective To evaluate the effects of dexmedetomidine pretreatment on extracellular sig?nal?regulated kinase ( ERK) pathway during acute lung injury in a rat model of liver transplantation. Meth?ods Sixty male Sprague?Dawley rats, weighing 235-250 g, were divided into 4 groups ( n=15 each) u?sing a random number table: sham operation group (group S), liver transplantation group (group LT), low?dose dexmedetomidine pretreatment group ( group LD ) and high?dose dexmedetomidine pretreatment group ( group HD) . In LT, LD and HD groups, the model of orthotopic liver transplantation was estab?lished, and the operation time was about 4 h. Dexmedetomidine 2?5 and 5?0μg·kg-1 ·h-1 were intrave?nously infused for 1 h starting from 1 h prior to clipping the hepatic artery and portal vein in LD and HD groups, respectively. The rats were sacrificed after the end of operation, and the lungs were removed for determination of wet to dry weight ratio ( W∕D ratio) , cell apoptosis and expression of ERK mRNA, ERK, phosphorylated ERK ( p?ERK) , Bcl?2 and Bax in lung tissues and for examination of the pathological chan?ges ( with light microscope) and ultrastructure of lung tissues ( with transmission electron microscope) . The
injured alveolus rate ( IAR) , apoptosis index ( AI) and ratio of Bcl?2 to Bax expression ( Bcl?2∕Bax ratio) were calculated. Results Compared to group S, the W∕D ratio, IAR, AI, expression of ERK?1 mRNA, ERK?2 mRNA, p?ERK, Bcl?2 and Bax and Bcl?2∕Bax ratio were significantly increased in LT, LD and HD groups ( P<0?05) . Compared to group LT, the W∕D ratio, IAR and AI were significantly decreased, the expression of ERK?1 mRNA, ERK?2 mRNA, p?ERK and Bcl?2 and Bcl?2∕Bax ratio were significantly increased, and the expression of Bax was significantly down?regulated in LD and HD groups (P<0?05). Compared to group LD, the W∕D ratio, IAR and AI were significantly decreased, the expression of ERK?1 mRNA, ERK?2 mRNA, p?ERK and Bcl?2 and Bcl?2∕Bax ratio were significantly increased, and the ex?pression of Bax was significantly down?regulated in group HD ( P<0?05) . The pathological changes of lung tissues were significantly attenuated in LD and HD groups as compared with group LT, and in group HD as compared with group LD. Conclusion The mechanism by which dexmedetomidine pretreatment mitigates cell apoptosis during acute lung injury is related to activation of ERK pathway in a rat model of liver trans?plantation.

Objective:To investigate the cardiac presentations and the possible influencing factors of severe and critical coronavirus disease 2019 (COVID-19).Methods:A retrospective study was conducted. Patients with severe and critical COVID-19 admitted to the Eighth People's Hospital of Guangzhou from January 21st to February 24th 2020 were enrolled. According to the clinical classification, the patients were divided into severe group and critical group. The myocardial injury markers, such as lactate dehydrogenase (LDH), aspartate aminotransferase (AST), creatine kinase (CK), cardiac troponin I (cTnI), myoglobin (MYO), MB isoenzyme of creatine kinase (CK-MB), B-type natriuretic peptide (BNP) and electrocardiogram (ECG) changes were compared between the two groups.Results:A total of 55 COVID-19 patients were selected, including 15 critical cases and 40 severe cases. The patients with severe and critical COVID-19 were male-dominated (61.8%), the average age was (61.2±13.0) years old, 83.6% (46 cases) of them had contact history of Hubei, 38.2% (21 cases) of them were complicated with hypertension. There was no significant difference in baseline data between the critical group and the severe group. Myocardial injury markers of critical and severe COVID-19 patients were increased in different proportion, LDH increased in most patients (20 severe cases and 7 critical cases), followed by AST (16 severe cases and 5 critical cases). There was significant difference in the number of patients with elevated CK between severe group and critical group (cases: 1 vs. 4, P = 0.027). Abnormal ECG was found in 39 of 42 patients with ECG examination. Nonspecific change of T wave was the most common. Before and after treatment, 9 of 15 patients with changes of ECG and myocardial injury markers had oxygenation index less than 100 mmHg (1 mmHg = 0.133 kPa), and the prominent changes of ECG were heart rate increasing and ST-T change. Conclusions:The increase of myocardial injury markers and abnormal ECG were not specific to the myocardial injury of severe and critical COVID-19 patients. At the same time, the dynamic changes of myocardial injury markers and ECG could reflect the situation of myocardial damage.

Abstract: Objective To investigate the clinical features and risk factors for severe tsutsugamushi disease, so as to provide reference for diagnosis and differentiation of severe tsutsugamushi disease as soon as possible. Methods The clinical data of 178 cases of inpatients with tsutsugamushi disease admitted to the Guangzhou Eighth People's Hospital, Guangzhou Medical University from January 2016 to September 2021 were collected and analyzed according to their gender, age, underlying diseases, clinical characteristics at admission, laboratory examination results within 24 hours of admission and epidemiological history. The patients were divided into the severe group and the non-severe group according to the diagnostic criteria. The data of clinical characteristics, laboratory examination and prognosis of the two groups were compared. Multivariate logistic regression analysis was performed on the variables with statistical significance and the receiver operating characteristic curve (ROC) was drawn. Results A total of 178 patients were included in this study, with 37 in the severe group and 141 in the non-severe group. Compared with the non-severe group, the age of the severe group was older, the underlying diseases were more, the incidence of dyspnea and the levels of white blood cell, total bilirubin, aspartate aminotransferase, lactate dehydrogenase, cystatin C, uric acid and serum creatinine were significantly increased, the levels of platelet and albumin were significantly decreased (all P<0.05). The dyspnea [odds ratio (OR value)=8.93, 95% confidence interval (CI): 1.200-66.424; P=0.032], total bilirubin (OR=1.091, 95%CI: 1.028-1.159; P=0.004) and serum creatinine (OR=1.052, 95%CI: 1.004-1.102; P=0.033) were independent risk factors for severe tsutsugamushi disease. The area under ROC curve of total bilirubin and serum creatinine were 0.777 and 0.764, respectively (both P<0.01), indicating high predictive value for severe tsutsugamushi disease. The optimal cut-off value for total bilirubin was 23.01 µmol/L, with a sensitivity of 54.10% and a specificity of 90.60%; the optimal cut-off value for creatinine was 126.45 µmol/L, with a sensitivity of 43.20% and a specificity of 100.00%. The case fatality rate of severe tsutsugamushi disease was 2.70%. Conclusions The patients with severe tsutsugamushi disease are older, and have more underlying diseases. Dyspnea, increased total bilirubin and elevated serum creatinine are independent risk factors for severe tsutsugamushi disease, which can help in the early identification of severe tsutsugamushi disease early.

Objective To evaluate the application value of early lung ultrasound score(LUS)in the eval-uation of severity and prognosis of severe pneumonia and investigate its correlations with oxygenation index(OI), alveolar-arterial oxygen difference(A-aDO2),lymphocyte count(LYM),positive end-expiratory pressure(PEEP), acute physiology and chronic health evaluation Ⅱ(APACHEⅡ)score,and clinical pulmonary infection score (CPIS). Methods Thirty severe pneumonia patients admitted to intensive care unit(ICU)of Guangzhou Eighth People's Hospital from May 2015 to July 2017 were enrolled,including 14 cases with low PEEP and 16 cases with high PEEP. Among them,17 patients were diagnosed with non-viral pneumonia and 13 ones with viral pneumonia;15 of them survived,and 15 died. The clinical data and cores of all patients were recorded by one observer,including baseline date,OI,A-aDO2,LYM,PEEP,and APACHEⅡ and CPIS score. The other observer was specifically responsible for pulmonary ultrasonography and LUS. The correlation between LUS and OI,A-aDO2,LYM,PEEP, as well as APACHEⅡand CPIS scores was analyzed by bivariate correlation analysis. Receiver operator character-istic curves(ROC)were plotted,and the prediction value,sensitivity and specificity of high PEEP and mortality by LUS were calculated respectively. Results LUS had a negative correlation with OI(r =-0.755,P = 0.000) and LYM(r =-0.518,P = 0.03),and a good positive correlation with A-aDO2(r = 0.642,P = 0.000),PEEP (r = 0.583,P = 0.001),APACHEⅡ(r = 0.461,P = 0.010)and CPIS(r = 0.595,P = 0.001)was respectively found. LUS in the survival group was significantly lower than the death group(15.00 ± 5.90 vs. 22.27 ± 4.68,P<0.01),low PEEP group was obviously lower than high PEEP group(14.23 ± 5.40 vs. 22.00 ± 4.98,P < 0.01), and there was no significant difference between non-viral pneumonia group and viral pneumonia group(18.59 ± 6.49 vs. 18.69 ± 6.56,P > 0.05). The area under ROC cure(AUC)was calculated:the predictive value for high PEEP by LUS was 19,with the sensitivity of 77% and specificity of 92%,and the patients with LUS > 17 had a high mortality,with the sensitivity for predicting death of 87% and specificity of 67%. Conclusion Bedside lung ultrasound can easily evaluate the changes in pulmonary ventilation area ,and early LUS has important clinical application value in assessing the severity and prognosis of severe pneumonia patients.