[Clinical Study of Peripherally Inserted Central Catheter-Related Thrombosis and Its Influence on the Blood Flow Status of the Inserted Veins in Cancer Patients].

Objective: To investigate the clinical features of peripherally inserted central catheter (PICC)-related thrombosis (PICCRT) within 2 weeks after PICC placement in cancer patients and its dynamic influence on the blood flow status of veins inserted with catheter, and to provide support for implementing thrombosis prevention and control measures. Methods: Between May 2019 and July 2020, patients who had solid tumors and who had PICC were prospectively enrolled at West China Hospital, Sichuan University. Scheduled color Doppler imaging was performed to examine the status of PICCRT formation at 8 points of time, with the first one conducted one day before the insertion of PICC and the other 7 completed within 2 weeks after the insertion of PICC. Then, based on whether patients had PICCRT, the patients were divided into two groups, a non-PICCRT group and a PICCRT group. The PICCRT group was further divided into two subgroups, an asymptomatic PICCRT group and a symptomatic PICCRT group, according to whether the patients had thrombosis-related symptoms and signs. Comparisons were made to study the incidence of PICCRT and the vascular diameter and the blood flow velocity in the veins inserted with catheters at different points of time in the patients of different groups. Results: Among 173 cancer patients in the cohort, 126 (72.8%) developed PICCRT, all of which occurred within 1 week after PICC insertion. There were 95 cases of asymptomatic PICCRT and 31 cases of symptomatic PICCRT. Before and after PICC insertion, the vascular diameter of both the asymptomatic and symptomatic PICCRT groups was significantly smaller than that of the non-PICCRT group and the blood flow velocity was significantly slower than that of the non-PICCRT group, with the difference continuing to increase with the prolongation of catheter indwelling time. Conclusion: Inserting catheters in veins with bigger vascular diameter and faster blood flow velocity may help reduce the incidence of PICCRT. The first week post catheter insertion is the key intervention period for the prevention of PICCRT.

[Antimicrobial susceptibility of community-acquired respiratory tract pathogens isolated from patients in primary hospitals in Shanghai from 2007 to 2010].

OBJECTIVE: To investigate the etiology of community-acquired respiratory tract infections (CARTI) and the antimicrobial resistance of the major pathogens in primary hospitals in Shanghai. METHODS: Patients with CARTI were prospectively recruited from 30 primary hospitals from December 2007 to July 2010. Those who had used antimicrobials within previous 2 weeks were excluded from the study. The clinical information such as temperature, white blood cell (WBC) count and percentage of neutrophils was recorded, and throat swab or deep cough sputum was collected to isolate pathogens. The specimens were collected and couriered to the Zhongshan Hospital microbiology laboratory within 2 h for bacterial culture. The minimal inhibition concentrations (MIC) of penicillin G, amoxicillin, cephradine, cephalexin, cefadroxil, sulfamethoxazole/trimethoprim and azithromycin were determined using the agar dilution test. RESULTS: Totally 806 qualified cases were enrolled in this study. Fever (T ≥ 38 °C) was present in 51.7% (n = 417) , and increased WBC count (>10×10(9)/L) was noted in 68.5% (n = 552 cases) of the patients. For bacterial culture, 184 strains were isolated from throat swabs of 688 patients with upper respiratory infection; the most frequently isolated bacteria were Haemophilus influenzae (44, 23.9%), Staphylococcus aureus (44, 23.9%) and Group G streptococcus (43, 23.0%). Thirty-three strains were isolated from 118 patients with lower respiratory infections, with Haemophilus influenza (21, 63.6%), Group G streptococcus (6,18.2%) and Streptococcus pneumoniae (3,9.1%) as the leading pathogens. All strains of Haemophilus influenzae were susceptible to azithromycin. The susceptibility rate of Streptococcus pneumoniae to penicillin was as high as 94.7%, while that to azithromycin was significantly decreased (21.1%). The MIC90 values of cephalexin, cefadroxil and ceftazidime for ß-hemolytic streptococcus spp were ≤ 2 mg/L. CONCLUSIONS: Upper respiratory infections were responsible for most cases of CARTI. The commonly used antimicrobials in primary hospitals kept a high susceptibility to the frequent pathogens for CARTI. However, Streptococcus pneumoniae showed a decreased susceptibility to macrolides, which should be used carefully as a single agent when treating CARTI.

[The incidence and risk factors for heterogeneous vancomycin intermediate Staphylococcus aureus].

OBJECTIVES: To investigate the prevalence of heterogeneous vancomycin intermediate Staphylococcus aureus (hVISA) and the sensitivity of hVISA to novel antibiotics, and to explore the risk factors and infection attributable mortality associated with hVISA infection. METHODS: A total of 456 methicillin resistant Staphylococcus aureus (MRSA) isolates were isolated in Zhongshan Hospital from January, 2008 to November, 2010. All MRSA isolates were investigated for hVISA by two agar screening methods BHIA5T (brain-heart infusion containing teicoplanin 5 mg/L) or BHIA6V (brain-heart infusion containing vancomycin 6 mg/L), as well as macroEtest method (MET). Possible hVISA isolates were tested by modified population analysis profile-area under the curve (PAP-AUC). The minimal inhibitory concentrations (MICs) of vancomycin, teicoplanin and linezolid were determined by microbroth dilution as recommended by Clinical Laboratory Standards Institute (CLSI). The contribution difference between hVISA and vancomycin susceptible Staphylococcus aureus (VSSA) in different MIC range was compared. A retrospective case-control study of the patients with hVISA infection or VSSA infection was carried out and statistical analysis was performed using t test, Mann-Whitney test, χ(2) test and Fisher exact test. RESULTS: A total of 105 isolates of hVISA were screened by BHIA5T and BHIA6V (23.0%) with other 23 isolates by MET (5.0%) and 21 by PAP-AUC (4.6%). All isolates were 100% sensitive to vancomycin, teicoplanin and linezolid. The vancomycin MIC [(1.76 ± 0.16) mg/L] in hVISA group was significantly higher than that in VSSA group [(1.09 ± 0.07) mg/L, P < 0.01], which was a potential risk factor for hVISA infection. The retrospective study showed chronic obstructive pulmonary disease (COPD) was also a risk factor for hVISA infection of the lower respiratory tract. No significant difference in infection attributable mortality was showed between the hVISA group and the VSSA group. CONCLUSIONS: The overall prevalence of hVISA in Zhongshan Hospital is estimated as 4.6%, while the prevalence of hVISA isolated from blood is as high as 12.5%. All isolates are 100% sensitive to vancomycin and linezolid. COPD is a risk factor for hVISA infection of the lower respiratory tract.

Etiology and antimicrobial resistance of community-acquired pneumonia in adult patients in China.

BACKGROUND: Appropriate antimicrobial therapy of community-acquired pneumonia (CAP) is mainly based on the distribution of etiology and antimicrobial resistance of major pathogens. We performed a prospective observational study of adult with CAP in 36 hospitals in China. METHODS: Etiological pathogens were isolated in each of the centers, and all of the isolated pathogens were sent to Zhongshan Hospital for antimicrobial susceptibility tests using agar dilution. RESULTS: A total of 593 patients were enrolled in this study, and 242 strains of bacteria were isolated from 225 patients. Streptococcus pneumoniae (79/242, 32.6%) was the most frequently isolated pathogen, followed by Haemophilus influenzae (55/242, 22.7%) and Klebsiella pneumoniae (25/242, 10.3%). Totally 527 patients underwent serological tests for atypical pathogens; Mycoplasma pneumoniae and Chlamydia pneumoniae infections were identified in 205 (38.9%) and 60 (11.4%) patients respectively. Legionella pneumophila infections were identified in 4.0% (13/324) of patients. The non-susceptibility rate of isolated Streptococcus pneumoniae to erythromycin and penicillin was 63.2% and 19.1% respectively. Six patients died from the disease, the 30-day mortality rate was 1.1% (6/533). CONCLUSIONS: The top three bacteria responsible for CAP in Chinese adults were Streptococcus pneumonia, Haemophilus influenza and Klebsiella pneumonia. There was also a high prevalence of atypical pathogens and mixed pathogens. The resistance rates of the major isolated pathogens were relatively low except for the high prevalence of macrolide resistance in Streptococcus pneumoniae.

[Genetic diversity of Legionella pneumophila serogroup 1 in hospital water distribution systems in Shanghai].

OBJECTIVE: To classify Legionella pneumophila serogroup 1 (LP1) isolated from the water distribution systems in hospitals of Shanghai by using genotying methods, and therefore to explore the genetic relationship between different genotypes. METHODS: LP1 was isolated from 8 hospitals in Shanghai, and strains of LP1 were subtyped using pulse field gel electrophoresis (PFGE). Genotyping results of PFGE were classified as dendrogram, and cluster analysis was used to compare the genetic characteristics of different strains. RESULTS: Twenty-four strains of LP1 were isolated from 193 water specimens. LP1 belonged to 6 PFGE genotypes, of which 21 belonged to 3 predominant genotypes. Different hospitals shared the same genotype, while some strains isolated from the same hospital had different genotypes. CONCLUSION: The genetic characteristics are stable in environmental LP1. Molecular biology techniques should be added to epidemiological study for hospital acquired legionellosis due to the genetic diversity in one hospital.

[The characteristics of CT imaging and diagnosis of pulmonary cryptococcosis in 42 cases with non-acquired immune deficiency syndrome].

OBJECTIVE: To further elucidate the CT characteristics and diagnostic approaches to non-acquired immune deficiency syndrome patients with pulmonary cryptococcosis. METHODS: The histories of forty-two pulmonary cryptococcosis (PC) patients diagnosed in Zhongshan Hospital from 2003-2008 were collected and analyzed for demography data, underlying conditions, clinical symptoms, chest CT and diagnostic studies. RESULTS: None of the 42 PC patients had avian or its feces contacting history, and 71.4% (30/42) of them were immunocompetent. The most frequent CT lesions were multiple nodules (67.9%) with peripheral predominance (67.9%), and cavitations (50%) often presented within them. Masses/consolidation (31.4%) and patching lesions (2.9%) could exist occasionally. Positive detection rates of non-aggressive examinations including sputum, bronchoalveolar lavage fluid and bronchofibroscopy aspiration were 4.3%, 8.3% and 6.3% respectively, while those of aggressive approaches including transbronchial lung biopsy (TBLB), thin needle aspiration biopsy (TNAB) and pneumonectomy by surgery were 64.7%, 64.3% and 100% respectively. Non-aggressive serum cryptococcus antigen test was performed in 14 patients who had been diagnosed by histopathology or pathogen culture, and all of them were positive. CONCLUSION: Our study suggests that PC is common in immunocompetent population. Avian or its feces contacting is not so important as used opinion to PC differential diagnosis. CT characteristics of PC are diversiform and always change very slowly. Besides the most frequent multiple nodules with subpleural predominance, pulmonary lesions can present as masses, consolidation or patching. Aggressive techniques such as TBLB and TNAB are benefit to clinical diagnosis of PC, and non-aggressive serum cryptococcus antigen test may be promising for its early diagnosis as well as clinical course follow-up and therapeutic effect evaluation.

[Cysteamine attenuates suppression of peripheral IL-2 and lymphocytic proliferation induced by ruminal and duodenal operations in goats].

Sixteen castrated male goats were randomly allocated into two groups (Control n=8; Experiment n=8) to investigate the effects of cysteamine on surgery-induced cellular immune suppression. The experiment commenced with 13 d of pre-operation (pre-Op), which contained 3 d of roughage-fed period (RP) and 10 d of roughage + concentrate-fed period (RCP), followed by first operation (Op-1) and then the second operation (Op-2). The goats were allowed to have 14 d of recovery between two operations. The fistulas were fixed to rumen walls in Op-1 and to duodenal walls in Op-2. Cysteamine (15 mg x kg(-1) x BW x d(-1)) was added to diet and fed to goats in Exp. group since RCP of pre-Op through whole experimental period. Blood was sampled through jugular vein from goats of both groups at pre-feeding of the last day of RP and RCP, 8 d after Op-1, 4 d and 13 d after Op-2, respectively to determine serum concentration of interlukin-2 (IL-2), cortisol, as well as PHA-stimulated lymphocytic proliferation rate (SI). In pre-operative periods there were no significant differences in concentration of IL-2 (0.82+/-0.1 vs 1.03+/-0.22 microg l(-1)) and cortisol (20.48+/-4.52 vs 20.80+/-9.93 microg l(-1)), as well as lymphocytic SI (90.72+/-7.25 vs 129.22+/-18.59) between Control and Exp. groups. The concentrations of IL-2 (0.82+/-0.1 vs 0.73+/-0.08 vs 0.55+/-0.12 microg l(-1)) and lymphocytic SI (90.72+/-7.25 vs 49.31+/-6.4 vs 7.09+/-1.66) in Control were depressed acutely (P<0.05), but cortisol concentration elevated (20.48+/-4.52 vs 26.67+/-10.51 vs 32.33+/-3.29 microg l(-1)) in post-operative periods (8 d after Op-1 and 4 d after Op-2), compared with those in RCP. While they remained unaltered in Exp. group except a slight decrease of lymphocytic SI at 4 d after Op-2. The different responses of Control and Exp. groups to surgery stress led to a 80-90% higher of IL-2 and about 3 times greater of SI in Exp. than those in Control, which was contributed by cysteamine administration. Our data show that in operated goats the cellular immune was suppressed by surgery stress, cysteamine administration prevented decreases of IL-2 and lymphocytic SI and increase of cortisol induced by surgery stress, consequently attenuates surgery-induced suppression of cellular immune activity.