Clinical efficacy of sequential invasive-noninvasive mechanical ventilation for chronic obstructive pulmonary disease complicated by type II respiratory failure / 中国基层医药

Objective:To investigate the clinical efficacy of sequential invasive-noninvasive mechanical ventilation for chronic obstructive pulmonary disease complicated by type II respiratory failure.Methods:Eighty-four patients with chronic obstructive pulmonary disease complicated by type II respiratory failure who received treatment in The First Affiliated Hospital of University of Science and Technology of China from January 2017 to December 2019 were included in this study. Patients were selected to withdraw the ventilator for performing a spontaneous breathing test according to recovery status. Patients who underwent invasive mechanical ventilation were included in the control group ( n = 42). Patients who underwent sequential invasive-noninvasive mechanical ventilation based on the pulmonary infection control window were included in the observation group. Mortality rate, reintubation rate, total ventilation time, length of hospital stay, heart rate, and blood gas analysis were compared between the two groups. Results:The length of hospital stay and total ventilation time in the observation group were (9.69 ± 1.94) days and (7.49 ± 1.53) days, respectively, which were significantly shorter than those in the control group ( t = 8.87, 5.10, both P < 0.05). Reintubation rate and mortality rate in the observation group were 4.76% (2/42) and 2.38% (1/42), respectively, which were significantly lower than those in the control group ( χ2 = 5.13, 3.90, both P < 0.05). In each group, heart rate, partial pressure of carbon dioxide and partial pressure of oxygen measured after treatment were superior to those measured before treatment (all P < 0.05). Conclusion:Based on pulmonary infection control window, invasive-noninvasive sequential ventilation for chronic obstructive pulmonary disease complicated by type II respiratory failure can not only reduce total ventilation time and length of hospital stay, remarkably improve clinical manifestations, but also effectively reduce reintubation rate and mortality rate.

Effect of the setting of laryngeal mask airway intracuff pressure based on airway peak pressure / 临床麻醉学杂志

Objective To explore the effects of airway peak pressure (Ppeak)guidance on the minimum laryngeal mask airway (LMA)intracuff pressure (ICP)setting during general anesthesia. Methods Sixty patients,aged 18-65 years,ASA physical status Ⅰ or Ⅱ,scheduled for elective gy-necological laparoscopic operation under general anesthesia were enrolled.The patients were randomly divided into pressure-regulated group (group P)and control group (group C)with 30 cases in each group.Size 4 Supreme LMA was inserted in after general anesthesia induction.Air was injected into the cuff to make ICP achieve 60 cm H2O.Volume-controlled ventilation was selected and Ppeak was recorded.In group P,all the gas in the LMA cuff was sucked out,and then air was injected in during expiration phase to make ICP achieve the level of Ppeak.If air leakage occurred,ICP was increased by 5 cm H2O each time until no gas leaked from the oropharynx.After pneumoperitoneum,the cuff was inflated to make ICP achieve 60 cm H2O and Ppeak was recorded once more.Then all the gas in the LMA cuff was sucked out,and air was injected into the cuff to make ICP achieve the level of Ppeak as the above method till the end of operation.In group C,ICP was maintained at 60 cm H2O.Ppeak, ICP and the intracuff gas volume were recorded before and after pneumoperitoneum.ICP during in-spiratory phase in the two groups was measured.Tidal volume during inspiration(Vti)and expiration (Vte)in the two groups were recorded,and the air leakage fraction (LF)was calculated as [(Vti-Vte)/Vti×100%].Laryngopharyngeal complications of all the patients in 24 hours after surgeries were also recorded.Results The intracuff gas volume before and after pneumoperitoneum and ICP were decreased significantly in group P compared with group C (P<0.05).There was no difference in LF between the two groups.Compared with group C,there were fewer patients with postoperative throat pain and swallow discomfort in group P (P<0.05).Conclusion ICP at the level of Ppeak plus 0-5 cm H2O during LMA ventilation can provide better sealing effect and less laryngopharyngeal com-plications.

Expression, purification and detection of activities of AprA and its inhibitor AprI from Pseudomonas aeruginosa / 军事医学

Objective To clone and express the alkaline protease AprA , one important virulence factor secreted by Pseudomonas aeruginosa(PAE)in Escherichia coli, to clone and express the inhibitor of AprA (AprI) and its substrate flagellin , and to detect the function of AprA and the inhibitory function of AprI .Methods The genes encoding AprA ,AprI and flagellin gene were amplified respectively by PCR using PAE PAO 1 genome DNA as the template .The expression vec-tors (pET-28a-AprA, pET-28a-AprI and pET-28a-Flagellin) were constructed and transformed into E.coli BL21(DE3) respectively.The recombinant AprA protein was expressed by IPTG induction and purified via denaturing and renaturation. The recombinant AprI and flagellin were expressed and purified by Ni 2+affinity chromatography .The cleavage activities of AprA on flagellin were detected by SDS-PAGE.Results Recombinant AprA , AprI and flagellin protein were expressed and purified .It was demonstrated that AprA cleaved flagellin , which was blocked by AprI .Conclusion Recombinant AprA could cleave its substrates as an alkaline protease , and its inhibitor AprI inhibits the activities of AprA .This study will contribute to further investigations on the role of AprA in the pathogenesis of PAE .

Expression, purification and antibody preparation of beta-hemolysin from Staphylo-coccus aureus / 军事医学

Objective To express the beta hemolysin ( Hlb), an important toxin secreted by Staphylococcus aureus ( S.aureus) and the mutant protein Hlb H-149-N , to detect the hemolytic activity of Hlb and Hlb H-149-N on sheep erythrocytes , and to prepare the specific antibodies against Hlb which can inhibit the hemolytic activity of Hlb .Methods Hlb gene was amplified by PCR using S.aureus NCTC-8325 genome DNA as template.The expression vector pET-28a-hlb was constructed and transformed into E.coli BL21(DE3).The expression vector pET28a-hlbH-149-Nwas constructed through point mutation.The recombinant Hlb and Hlb H-149-N protein were expressed and purified by Ni 2+affinity chromatography .The hemolytic activity of Hlb and Hlb H-149-N was measured by sheep erythrocyte lysis assay .Results Recombinant Hlb protein and the mutant were obtained .Further investigations showed that Hlb could significantly induce the lysis of SRBC while HlbH-149-N could not.The specific polyclonal antibodies against Hlb (anti-Hlb) were prepared.It was found that anti-Hlb recognized Hlb and Hlb H-149-N .Moreover , it was found that anti-Hlb blocked the hemolytic activity of Hlb .Conclusion The recombinant Hlb protein with high hemolytic activity and Hlb H-149-N without hemolytic activity are obtained while its neutralized antibody is pepared .Hlb from S.aureus has different hemolytic effects on erythrocytes from various species .Our findings will facilitate the investigation on the role of Hlb in the pathogenesis of S.aureus.

Expression, purification and antibody preparation of alpha-hemolysin from Staphylo-coccus aureus / 军事医学

Objective To clone and express alpha hemolysin ( Hla ) , one important virulence factor secreted by Staphylococcus aureus in Escherichia coli to tdetect the hemolytic activity of Hla on erythrocytes from diffrerent species ,and to prepare specific antibodies against Hla that can inhibit the hemolytic activity of Hla .Methods Hla gene was amplified by PCR using S.aureus NCTC-8325 genome DNA as a template.The expression vector pET-28a-Hla was constructed and transformed into E.coli BL21(DE3).The recombinant Hla protein was expressed by IPTG induction ,and then purified by Ni2+affinity chromatography .The hemolytic activity of Hla was measured by erythrocyte lysis assays .Results Soluble recombinant Hla protein was expressed and purified .Further investigations showed that Hla could significantly induce the lysis of rabbit erythrocytes .However , erythrocytes from humans or sheep were more resistant to the lysis mediated by Hla . The specific polyclonal antibodies against Hla ( anti-Hla) were prepared and detected by ELISA .Moreover, it was found that anti-Hla could inhibit the hemolytic activity of Hla .Conclusion We found that Hla from S.aureus has different hemolytic effects on erythrocytes from various species .The prepared Hla-antibodies can specifically block the hemolytic activity of Hla.

Clinical significance of simultaneous determination of serum creatine kinase isoenzyme and creatine kinase ratio and cardiac troponin Ⅰ in disease condition judgment of patients with acute organophosphorus pesticide poisoning / 中国医师进修杂志

ObjectiveTo investigate the changes of serum creatine kinase isoenzyme (CK-MB) and creatine kinase (CK) ratio(CK-MB/CK) and cardiac troponin I(cTnI) simultaneously in patients with acute organophosphorus pesticide poisoning (AOPP) and the clinical value in disease condition judgment.Methods Eight hundred and sixty-eight AOPP patients without disease history of heart,lung,brain,kidney,muscle and other connective tissue were extracted 4 ml of fasting venous blood to determine CK,CK-MB and cTnI simultaneously at 2,12,24,48,96 and 120 hours after poisoning,and the CK-MB/CK was calculated.There were 279 mild poisoning cases (mild poisoning group),289 moderate poisoning cases (moderate poisoning group) and 300 severe poisoning group (severe poisoning group) ; and 208 cases with intermediate myasthenia syndrome (IMS)(IMS group) and 660 cases without IMS (non-IMS group).The result was compared with 288 healthy people (control group) in the same period.Results ( 1 ) The CK,CK-MB and cTnI of mild,moderate and severe poisoning groups between 2 to 12 h,13 to 24 h,25 to 120 h after poisoning were significandy higher than those in control group,CK-MB/CK was obviously lower (P ＜ 0.01 ).The CK,CK-MB,cTnI and CK-MB/CK had significant differences between each two of mild,moderate and severe poisoning groups (P＜ 0.01 or ＜ 0.05).The CK,CK-MB and cTnI of IMS group in 2 to120 h after poisoning were significantly higher than those in non-IMS group,and CK-MB/CK was lower (P ＜ 0.05 or ＜ 0.01 ).In IMS group,the rates of sudden cardiac death (SCD) and multiple organ dysfunction syndrome (MODS) were 23.08％(48/208),37.50％(78/208) respectively,while 4.24％(28/660),9.85％(65/660) in non-IMS group.The incidence of SCD and MODS of two groups had statistical significance (P ＜ 0.01 ).(2) According to IMS and non-IMS group,discriminant equation with independent variables of cTnI (X1), CK (X2) and CK-MB/CK (X3) was established:Y =-0.0014X1 + 0.0225X2 + 65.2376X3,F=21.4911,P ＜ 0.01.The discriminant critical value(Y0) was 2.8124.If Y ＜ 2.8124 belonged to IMS group and Y ≥2.8124 was in non-IMS group,the contribution rates of X1,X2 and X3 were 34.5％,25.4％ and 40.1％ respectively.The coincident rate of return was 91.26％.ConclusionsCK-MB/CK change has negative correlation with poisoning degree of AOPP;cTnI level is positively correlated with AOPP poisoning degree.they may be used to assist the clinical classification,disease judgement and to guide the emergency,treatment and prognosis assessment of AOPP.The function equation with cTnI,CK and CK-MB/CK can be used as effective prediction indexes of IMS,MODS and SCD in early period.

A Novel Neutralizing epitope of Human cytomegalovirus glycoprotein M Screened by Phage Display / 生物化学与生物物理进展

Human cytomegalovirus glycoprotein complex Ⅱ (gC Ⅱ ) consists of two glycoproteins, gM and gN. Although gC Ⅱ specific IgG purified from HCMV positive patient sera can neutralize HCMV, there has been no report on the generation of virus-neutralizing antibodies by immunizing with one epitope of gM. The epitope, termed MAD, was screened from random phage peptide library by subtractive strategy. The peptide sequence of MAD was highly homologous with 32~38 amino acids of HCMV gM. Mice immunized with MAD coupled with keyhole limpet hemocyanin (KLH) could produce specific antibodies against MAD, and the antibodies obtained could bind not only native HCMV particles, but also the recombinant gM30～78 peptide. ELISA analysis results showed that MAD could specifically bind HCMV-positive human serum samples. Virus-neutralizing assay results demonstrated that the antibodies against MAD could inhibit HCMV strain AD169 entering the human embryonic lung cells. The results suggested that MAD could be used as a new potential protective antigen in the development of HCMV vaccine.

THE HISTOCHEMICAL STUDY OF MUCO-POLYSACCHRIDE IN THE TISSE OF GASTRIC CARCINOMA / 解剖学报

Twenty-fine samples of stomach and 25 samples of adenocarcinoma stomach were employed for this study. The former have been collected from the patients of duodenal ulcer. Specimens were taken from the large curvature and pylorus. In the adenocarcinoma of stomach, materials were taken from the cancer focus and the cancer margins, fixed in 10% formalin-GaCl_2 Solution, embedded in paraffin and cut at 5? in thickness. Then they were examined with defferent reactions of histochemistry; PAS, Alcian blue (AB), Toludine blue (TB) and Barnett's method. The surface of gastric mucosa obtained from patients of duodenal ulcer after subtotalgastrectomy was covered with a substance which consists of neutral and acid mucopolysaccharide and protein. The epithelial cells of the mucosa contains large amount of neutral muco-polysaccharide. The cells of the neck of gastric gland contain quite a bit of acid muco-polysaccharide, but the cells of the deep segments of the glands do not show any of it. The cells of adenocarcinoma of stomach contain a different deal material mixture which consists of acid muco-polusaccharide and protein. The surface of the cavity in the well-differenlialed cancer glands was covered by a positive substance in TB, AB method, which forms a thin layer of membrance. An evenly distributed substance in the cavity of carcinoma gland was shown with positive reactions of PAS, AB, TB and protein. The degenerated cells show a positive reactions of PAS and protein. The cells of low-differentiated cancer were surrounded with a superficial layer of the acid mucopolysaccharide. The interstitia in the invaded margines often showed clear, distinct positive PAS and TB reactions. It indicates that it cortains more chondroitin sulfuric acid and the hyaline acid. In the superficial layers of mucosa of the cancer tissue, the epithelial cellswere often to have less positive substance than that of the membrane in the parts of cancer margine, it means a lesser amount of neutral-polysaccharide. But the acid muco-polysaccharide in the surface of cancer and its metaplastic margin clearly increases in amount than the metaplastic area far away from the cancer focus. This report discussed the significance of the increased muco-polysaccharide in the tissue of the gastric cancer.