Intrahospital transmission and infection control of Candida auris originating from a severely infected COVID-19 patient transferred abroad

BACKGROUND

Intrahospital spread of Candida auris, which survives tenaciously in many environments, can cause sustained colonization and infection. A large outbreak of C. auris was experienced in the intensive care units (ICUs) at the study hospital during the coronavirus disease 2019 (COVID-19) pandemic.

METHODS

The index patient with severe COVID-19, who was transferred from Vietnam in January 2022, developed C. auris candidaemia 10 days after hospitalization. From mid-June 2022 to January 2023, strengthened infection prevention and control (IPC) measures were implemented in three ICUs: (1) contact precautions and isolation (CPI) for C. auris-positive cases; (2) surveillance cultures including point-prevalence (N=718) for patients or close contacts or ICU-resident healthcare workers (HCWs); (3) intensive environmental disinfection with 10-fold diluted bleach; and (4) 2% chlorhexidine bathing for all ICU patients. Environmental cultures (ECx) on surfaces and shared objects (N=276) were conducted until early September 2022, when all ECx were negative.

RESULTS

Among 53 C. auris-positive patients between February 2022 and January 2023, invasive infections resulted in seven cases of candidaemia and one case of pneumonia. C. auris was isolated from reusable tympanic thermometers (TTMs) contaminated with earwax. The isolation rate of C. auris in ECx decreased from 6.8% in June 2022 to 2.0% in August 2022, and was no longer detected in TTMs. Colonization in HCWs was remarkably rare (0.5%). The number of C. auris-positive patients peaked in July (N=10) then decreased gradually. By January 2023, no C. auris were isolated in the ICU.

CONCLUSION

Aggressive IPC measures with CPI, ECx and surveillance, decontamination of TTMs, and bathing were effective in successfully controlling this C. auris outbreak.

Association of body mass index and bloodstream infections in patients on extracorporeal membrane oxygenation: a single-centre, retrospective, cohort study

BACKGROUND

Obesity is associated with poor clinical outcomes in critically ill patients. However, under some clinical conditions, obesity has protective effects. Bloodstream infections (BSI) are among the most common nosocomial infections associated with extracorporeal membrane oxygenation (ECMO). BSI during ECMO is associated with higher mortality rates and poorer clinical outcomes.

AIM

To analyse whether body mass index (BMI) is associated with BSI during ECMO or with in-hospital mortality.

METHODS

All adult patients who had received ECMO support for >48 h were included in the analysis. The analysis of total duration of ECMO support, in-hospital mortality and BSI was stratified by BMI category. The Cox proportional hazards model was used to compare the risk of BSI among BMI categories.

FINDINGS

In total, 473 patients were enrolled in the study. The average age was 56.5 years and 65.3% were men. The total duration of ECMO was approximately 11.8 days, with a mortality rate of 47.1%. The incidence rates of BSI and candidaemia were 20.5% and 5.5%, respectively. The underweight group required ECMO for respiratory support, whereas the overweight and obese groups required ECMO for cardiogenic support (P<0.0001). No significant difference in BSI rate was found (P=0.784). However, after adjusting for clinical factors, patients in Group 4 (BMI 25.0-<30.0 kg/m2) exhibited lower mortality compared with patients in Group 2 (normal BMI) (P=0.004).

CONCLUSION

BMI was not associated with risk of BSI, but patients with higher BMI showed lower in-hospital mortality associated with ECMO support.

Midline catheters in the operating room

Backgrounds

Among various vascular access devices, midline catheters (MCs) are commonly used in emergency departments, but rarely in operating rooms.

Aims

To evaluate the feasibility and safety of MCs in the operating room.

Materials and Methods

This was a retrospective study. The medical records of patients who underwent MC placement in the operating room from October 2020 to July 2022 were reviewed. The rates of successful catheter insertion as well as major and minor complications were assessed.

Results

Successful catheter insertions were achieved in 149 of 161 patients (92.5%). The median dwell time of midlines was eight days (IQR: 6-10 days). A major or minor complication occurred in 6.7% of the midlines. The rates of major complications of occlusion, upper extremity deep vein thrombosis (DVT), and catheter-related bloodstream infection were 1.3%, 0.7%, and 0%, respectively.

Conclusions

Placement of MCs in the operating room was feasible and safe. Also, the procedure provides an acceptable alternative for replacing central line catheters and peripherally inserted central catheters.

[Evaluation of right ventricular function using two-dimensional speckle tracking echocardiography and analysis of the risk factors for right ventricular dysfunction in patients with silicosis]

Objective: To evaluate the right ventricular function using two-dimensional speckle tracking echocardiography (2-D STE) and analyze the associated risk factors of right ventricular dysfunction in patients with silicosis. Methods: All 104 patients with silicosis treated in the Department of Occupational Medicine and Toxicology in Beijing Chao-Yang Hospital, Capital Medical University from May 2021 to September 2022 were enrolled in this study in October 2022. The clinical information of patients such as general data, arterial blood gas analysis and pulmonary function test were collected. The right ventricular function of patients was evaluated by 2-D STE-derived right ventricular free wall longitudinal strain (RVFWLS) and conventional echocardiographic-derived parameters, including right ventricular fractional area change (RVFAC), tricuspid annular plane systolic excursion (TAPSE) and doppler tissue imaging-derived tricuspid lateral annular systolic velocity (S'), respectively. Based on their RVFWLS, the patients were divided into right ventricular dysfunction group and normal right ventricular function group. Risk factors for right ventricular dysfunction in patients with silicosis were analyzed using binary logistic regression analysis. Results: A total of 104 silicosis patients were enrolled, with aneverage age (65.52±11.18) years old, among whom including 57 cases diagnosed with stage Ⅰ/Ⅱ silicosis and 47 cases diagnosed with stage Ⅲ silicosis. 26 (25.00%) patients concurrent right ventricular dysfunction. The abnormal rates of RVFAC, TAPSE and S' in patients were 16.35% (17 cases), 21.15% (22 cases) and 6.73% (7 cases), respectively. The RVFAC and TAPSE in right ventricular dysfunction group were lower than those in normal right ventricular function group, and the incidence of pulmonary arterial systolic pressure ≥36 mmHg was higher than that in normal right ventricular function group (P<0.05). Logistic regression analysis showed that arterial partial pressure of oxygen (OR=0.932, 95%CI: 0.885-0.981, P=0.007) was the protective factor, and the forced expiratory volume in 1 second (FEV(1)) /forced vital capacity (FVC) ratio<70% (OR=5.484, 95%CI: 1.049-28.662, P=0.044) and stage Ⅲ silicosis (OR=6.343, 95%CI: 1.698-23.697, P=0.007) were the risk factors for silicosis patients concurrent right ventricular dysfunction. Conclusion: The incidence of right ventricular dysfunction is higher in patients with stage Ⅲ silicosis than that in patients with stage Ⅰ/Ⅱ silicosis. Using 2-D STE can help the early detection of silicosis with right ventricular dysfunction. Hypoxemia, airflow limitation and the stage Ⅲ silicosis are the risk factors for silicosis patients concurrent right ventricular dysfunction.

[Four cases of acute ethylene glycol poisoning]

Ethylene glycol is the main component of antifreeze, due to its special sweetness, it is easy to cause misuse. In this paper, the clinical data of 4 cases of acute ethylene glycol poisoning admitted to Beijing Chao-Yang Hospital from August 2016 to August 2021 were retrospectively analyzed to explore the clinical characteristics of acute ethylene glycol poisoning cases. Early and accurate assessment of the disease and early hemodialysis treatment is the key to cure acute ethylene glycol poisoning.

[Clinical features and follow-up outcomes of optic nerve injury induced by acute methanol poisoning]

Acute methanol poisoning harms the optic nerve and central nervous system, can cause irreversible damage, even coma or death in severe cases. This article reported four cases of methanol poisoning. 3 patients mistakenly ingested industrial alcohol containing methanol, the most serious patient suffered from coma, vision loss and other symptoms, the blood methanol concentration was 869.3 μg/ml. Another patient was poisoning caused by inhalation of methanol, with symptoms such as total blindness in the right eye and decreased visual acuity in the left eye. After active supportive treatment, 2 patients had partial recovery of visual acuity, and 2 patients had no sequelae. This article discussed the clinical features, treatment and prognosis of optic nerve damage caused by methanol poisoning, in order to raise awareness of this disease.

[Study on the difference of curative effect of conventional mercury displacement treatment on mercury in brain and kidney]

Objective: To explore the expulsion effect of sodium dimercaptopropanesulfonate (DMPS) on mercury in different organs of mercury poisoning and the therapeutic effect of glutathione (GSH) combined with antioxidant therapy on mercury poisoning. Methods: In February 2019, 50 SPF male SD rats were randomly divided into 5 groups, 10 rats in each group: A (saline negative control group) , B (HgCL2 positive control group) , treatment group (C: intramuscular injection of DMPS 15 mg/kg treatment, D: intramuscular injection of DMPS30 mg/kg treatment, E: intramuscular injection of DMPS 15 mg/kg and intraperitoneal injection of GSH200 mg/kg treatment) . Rats in group B, C, D and E were subcutaneously injected with mercury chloride solution (1 mg/kg) to establish a rat model of subacute mercury poisoning kidney injury. Rats in group A were subcutaneously injected with normal saline. After the establishment of the model, rats in the treatment group were injected with DMPS and GSH. Rats in group A and group B were injected with normal saline. At 21 d (treatment 7 d) and 28 d (treatment 14 d) after exposure, urine and blood samples of 5 rats in each group were collected. Blood biochemistry, urine mercury, urine microalbumin and mercury content in renal cortex, cerebral cortex and cerebellum were detected. Results: After exposure to mercury, the contents of mercury in renal cortex, cerebrum and cerebellum of rats in group B, C, D and E increased, and urine microalbumin increased. Pathology showed renal tubular injury and renal interstitial inflammation. Compared with group B, urinary mercury and renal cortex mercury in group C, D and E decreased rapidly after DMPS treatment, and there was no significant decrease in mercury levels in cerebellum and cerebral cortex of rats, accompanied by transient increase in urinary albumin after DMPS treatment (P<0.05) ; the renal interstitial inflammation in group E was improved after GSH treatment. There was a positive correlation between urinary mercury and the contents of mercury in renal cortex, cerebral cortex and cerebellum (r=0.61, 0.47, 0.48, P<0.05) . Conclusion: DMPS mercury expulsion treatment can significantly reduce the level of metal mercury in the kidney, and there is no significant change in the level of metal mercury in the cortex and cerebellum.

Risk Factors Affecting Complications of Access Site in Vascular Intervention through Common Femoral Artery

Backgrounds

Traditionally, vascular interventions have been performed through the femoral artery.

Aims

The purpose of this study was to evaluate risk factors affecting access-site complications in patients with hepatocellular carcinoma or peripheral arterial disease in lower extremity who underwent vascular intervention by accessing the common femoral artery (CFA).

Patients and Methods

From December 2015 to November 2018, 287 patients underwent transarterial chemoembolization (TACE) or peripheral vascular intervention with ultrasound (US)-guided CFA access. Standard 18-gauge (G) access was used in 127 patients and Micropuncture® 21-G needles in 160 patients. Most access sites were managed with vascular closure devices and several were managed with manual compression. Within 24 hours after the procedure, all patients underwent US to evaluate the puncture site.

Results

Access-site complications occurred in 55 of 287 patients: 34 hematomas (11.9%), 20 pseudoaneurysms (7.0%), and 1 dissection (0.4%). In the crude model, risk factors related to access-site complications were the usage of 18-G needles (OR, 2.18; 95% CI, 1.17-4.07; P = 0.014), smoking (OR, 2.23; 95% CI, 1.16-4.27; P = 0.016), and approach route (OR, 3.23; 95% CI, 1.33-7.82; P = 0.009). Needle size (OR, 2.13; 95% CI, 1.10-4.12; P = 0.025) was the only factor associated with access-site complications in the adjusted model.

Conclusion

Needle profile was the only factor associated with access-site complications in this study. Therefore, a needle with a smaller profile than an 18-G needle will reduce the incidence of complications at the access site.

[Analysis of the pulmonary function characteristics and associated factors in silicosis patients with progressive massive fibrosis]

Objective: To investigate the characteristics of and associated risk factors for pulmonary dysfunction in silicosis patients with progressive massive fibrosis (PMF) . Methods: In-patients with PMF treated in the Department of Occupational Medicine and Toxicology in Beijing Chao-Yang Hospital, Capital Medical University from June 2014 to October 2020 were enrolled in this study. Based on their pulmonary ventilation function, the patients were divided into normal ventilation group, obstructive ventilation dysfunction group, restrictive ventilation dysfunction group, and mixed ventilation dysfunction group. The location and area of the large opacity and the grade of emphysema were evaluated by high-resolution CT (HRCT) of the chest. Based on the location, the large opacity was classified into central type, peripheral type, and mixed type. Results: A total of 115 silicosis patients with PMF were enrolled, with 85 (73.91%) having different types of pulmonary dysfunction, including 36 cases (31.30%) in the obstructive ventilation dysfunction group, 9 cases (7.83%) in the restrictive ventilation dysfunction group and 40 cases (34.78%) in the mixed ventilation dysfunction group. As for the location of the large opacity, 41 cases (35.65%) were central type, 52 cases (45.22%) were peripheral type, and 22 cases (19.13%) were mixed type. Logistic regression analysis showed that the central large opacity and grade 3-4 emphysema were risk factors for obstructive ventilation dysfunction (OR=52.179, 5.500, P<0.05) , class C large opacity was the risk factor for restrictive ventilation dysfunction (OR=33.146, P<0.05) , class B, class C large opacity and central large opacity were the risk factors for mixed ventilation dysfunction (OR=6.414, 11.561, 19.600, P<0.05) . Conclusion: In silicosis patients with PMF, the incidence rate of pulmonary ventilation dysfunction is higher, mainly obstructive and mixed ventilation dysfunction. The area and location of large opacity are associated with the incidence and types of pulmonary ventilation dysfunction.

[A case of oral hydrochloric acid poisoning treatment]

The case of oral hydrochloric acid poisoning is rare in clinic, and it is easy to be misdiagnosed when the poison is not clear. The clinical data of 1 case of oral hydrochloric acid poisoning successfully treated was retrospectively analyzed to provide reference for diagnosis and treatment of similar clinical cases.

[Analysis of related risk factors in the occurrence of mercury-toxic nephrotic syndrome]

Objective: To analyse the clinical characteristics of mercury-toxic nephrotic syndrome and to find the risk factors. Methods: A total of 126 patients with mercury-toxic admitted to Beijing Chaoyang Hospital from January 2017 to January 2020 were selected as the research objectives. General data such as age, gender, mercury exposure history of all patients and laboratory data such as urine mercury and urine creatinine were collected. The clinical manifestations and pathological types of patients with mercury-toxic nephrotic syndrome were analyzed, and the risk factors of mercury-toxic nephrotic syndrome were found by univariate and multivariate logistic regression analysis. Results: Among the 24 patients with mercury-toxic nephrotic syndrome, 1 was poisoned by respiratory tract, 6 were poisoned by digestive tract, and 17 were poisoned by skin absorption. In addition to the manifestations of kidney injury, some of the patients also showed neurological symptoms such as dizziness, fatigue, hand tremor, and limb pain. The main pathological types were membranous nephropathy (9 cases) and micropathological nephropathy (10 cases) . The results of multivariate logistic regression analysis showed that the digestive tract and skin absorption pathways of mercury were risk factors for mercury-toxic nephrotic syndrome (OR=21.099, 23.840, P<0.05) . Conclusion: The absorption pathway of mercury has an important influence on the pathogenesis of mercury-toxic nephrotic syndrome, especially in patients with mercury poisoning absorbed by the skin and digestive tract, the risk of complicating nephrotic syndrome is higher.

[Clinical characteristics, treatment and outcome of chronic mercury-related nephrotic syndrome]

Objective: To investigate the etiology, clinical features, treatment and outcome of nephrotic syndrome associated with chronic mercury poisoning. Methods: From June 2013 to April 2018, Beijing Chaoyang Hospital, Capital Medical University received 33 patients with chronic mercury-neutral nephrotic syndrome. The clinical manifestations, laboratory tests, treatment methods, and outcomes were analyzed. Results: Among the 33 patients, 27 patients had mercury exposure due to daily-life contact and the other 6 patients were caused by iatrogenic mercury. The symptom was characterized by typical nephrotic syndrome such as lower extremity edema and proteinuria at first onset. The treatment was based on mercury-removing treatment, 19 cases were treated with mercury removal alone, 16 cases were completely relieved; 10 cases were treated with mercury removal and glucocorticoids, all of which were completely relieved; 4 cases were treated with mercury removal, glucocorticoids and immunosuppressive agents, all complete remission; clinical complete remission rate is about 90.9% (30 cases in total) . Urinary mercury levels decreased the fastest between the first and second courses of mercury treatment, but the total amount of urine protein increased. As the amount of urinary mercury excreted increased, the total amount of urine protein decreased gradually (Z=2.86, P<0.01) . Conclusion: The clinical features of chronic mercury-induced nephrotic syndrome are non-specific, easy to be misdiagnosed and missed. The treatment is mainly treated with mercury removal treatment. The prognosis is good. In severe cases, glucocorticoid therapy can be supplemented.

Acquisition of Carbapenemase-Producing Enterobacteriaceae in Solid Organ Transplantation Recipients

BACKGROUND

Carbapenemase-producing Enterobacteriaceae (CPE) can lead to life-threatening outcomes with rapid spread of the carbapenemase gene in solid organ transplantation (SOT) recipients because of limitations of available antibiotics. We examined the characteristics and importance of CPE acquisition in SOT recipients with large numbers of CPE isolates.

METHODS

Between November 2015 and October 2016, 584 CPE isolates were found in 37 recipients and verified by carbapenemase gene multiplex polymerase chain reaction (PCR). One hundred recipients with at least 2 negative results in carbapenemase PCR for stool surveillance and no CPE isolates in clinical samples were retrospectively included.

RESULTS

Most CPE isolates were Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae (546, 93.5%). The most frequent transplantation organ was lung (43.3%), and the most common sample with CPE isolates other than stool was respiratory tract (22.6%). The median time between SOT and first CPE acquisition was 7 days. All-cause mortality was significantly higher in recipients with CPE than in those without CPE (24.3% vs 10.0%; P = .03). In multivariate regression analysis, stool colonization of vancomycin-resistant Enterococci and/or Clostridium difficile during 30 days before SOT (odds ratio [OR], 3.28; 95% CI, 1.24-8.68; P = .02), lung transplantation (OR, 4.50; 95% CI, 1.19-17.03; P = .03), and intensive care unit stay ≥2 weeks (OR, 6.21; 95% CI, 1.72-22.45; P = .005) were associated with acquisition of CPE.

CONCLUSIONS

Early posttransplantation CPE acquisition may affect the clinical outcome of SOT recipients. Careful screening for CPE during the early posttransplantation period would be meaningful in recipients with risk factors.

Use of vertebral body units to locate the cavoatrial junction for optimum central venous catheter tip positioning

BACKGROUND

Central venous catheter (CVC) placement plays an important role in clinical practice; however, optimal positioning of the CVC tip remains a controversial issue. The objective of this study was to evaluate the use of vertebral body unit (VBUs), to locate the cavoatrial junction (CAJ), for optimal CVC tip placement based on chest radiography (CXR) using the carina as a landmark.

METHODS

524 patients who underwent coronary computed tomographic angiography (CTA) and CXR were included. The position of the CAJ was identified using VBUs, and the efficacy of VBUs for locating the CAJ with the carina as a landmark was analysed using multiple regression analysis. A VBU was defined as the distance between two adjacent vertebral bodies, including the inter-vertebral disk space.

RESULTS

The mean (sd) distance from the carina to the superior CAJ was 54.3 (9.7) mm on CTA; the mean distance in VBUs at the level of the carina was 21.4 (1.7) mm on CTA and 22.6 (2.1) mm on CXR. The mean CAJ position was 2.5 VBUs below the carina on CTA and 2.4 VBUs below on CXR with 95% limits of agreement between -0.6 and +0.3.

CONCLUSIONS

The position of the CVC tip in relation to the carina can be described using the thoracic spine as an internal ruler, and the position of the CAJ in adults was reliably estimated to be 2.4 VBUs below the carina.

CLINICAL TRIAL REGISTRATION

KCT0001319.

HIV-associated neurocognitive disorder in HIV-infected Koreans: the Korean NeuroAIDS Project

OBJECTIVES

HIV-associated neurocognitive disorder (HAND) is an independent predictor of early mortality and is associated with many difficulties in activities of daily living. We sought to determine the prevalence of and risk factors for HAND in HIV-infected Koreans. In addition, we investigated the performance of screening tools and components of neuropsychological (NP) tests for diagnosing HAND.

METHODS

HIV-infected patients were enrolled consecutively from two different urban teaching hospitals in Seoul, South Korea between March 2012 and September 2012. Participants completed a detailed NP assessment of six cognitive domains commonly affected by HIV. The Frascati criteria were used for diagnosing HAND. Four key questions, the International HIV Dementia Scale (IHDS) and Montreal Cognitive Assessment (MoCA)-K were also assessed as potential tools for screening for HAND.

RESULTS

Among the 194 participants, the prevalence of HAND was 26.3%. Asymptomatic neurocognitive impairment and minor neurocognitive disorder accounted for 52.9 and 47.1% of the patients with HAND, respectively. In multivariate analysis, haemoglobin (Hb) level ≤ 13 g/dL (P = 0.046) and current use of a protease inhibitor-based regimen (P = 0.031) were independent risk factors for HAND. The sensitivity and specificity of the IHDS were 72.6 and 60.8%, and those of MoCA-K were 52.9 and 73.4%, respectively. The IHDS (P < 0.001) and MoCA-K (P < 0.001) were both useful for screening for HAND. Among NP tests, the sensitivity and specificity of the Grooved Pegboard Test were 90.2 and 72.0%, and those of the Wisconsin Card Sorting Test were 61.2 and 84.4%, respectively.

CONCLUSIONS

HAND is a prevalent comorbidity in HIV-infected Koreans. Active screening and diagnosis with effective tools, such as the IHDS, MoCA-K and Grooved Pegboard Test, could be used to identify this important complication.

Mortality risk factors of Acinetobacter baumannii bacteraemia

BACKGROUND

Acinetobacter baumannii is one of the most important nosocomial pathogens, and its multiple antibiotic resistance has emerged as an obstacle in the treatment of these infections worldwide.

AIMS

To identify risk factors of mortality for A. baumannii bacteraemia.

METHODS

A retrospective cohort study of 72 patients with significant A. baumannii bacteraemia was conducted to evaluate risk factors for mortality.

RESULTS

The median age of the 72 enrolled patients was 48 years, 96% of the cases were hospital-acquired, and the bacteraemia-related mortality rate was 29% (21 of 72 patients). Univariate analysis revealed that the risk factors for mortality included: an elevated acute physiology and chronic health evaluation (APACHE II) score, receipt of in vitro ineffective definitive antimicrobial therapy, in vitro A. baumannii resistance to cefoperazone/ sulbactam, neutropenia, and presentation with septic shock. Multivariate analysis reveals that the independent risk factors for mortality are neutropenia and elevated APACHE II scores.

CONCLUSION

Risk factors such as neutropenia and elevated APACHE II scores are found to be associated with higher mortality rates of A. baumannii bacteraemia. Further study is necessary for the determination of optimal strategies for both the prevention and treatment of these infections.

Synergic in-vitro activity of imipenem and sulbactam against Acinetobacter baumannii

The interaction between sulbactam and imipenem was evaluated with four clinical isolates of Acinetobacter baumannii, including two isolates resistant to imipenem, one of which produced IMP-1 metallo-beta-lactamase. Two isolates (one of which was imipenem-resistant) were sulbactam-resistant by undefined mechanisms. MICs were determined by standard broth microdilution methods. Time-kill assays with imipenem and sulbactam, alone or in combination at 0.5 x MIC and 1 x MIC, showed a synergic effect in all four isolates of A. baumannii after incubation for 0, 4, 8 and > 24 h at 35 degrees C.

Complete 1H and 13C assignments of 8-C-beta-D-[2-O-(E)-p-coumaroyl]glucopyranosyl-2-(2-hydroxy)propyl-7-methoxy-5-methylchromone

1H and 13C NMR spectra of 8-C-beta-D-[2-O-(E)-p-coumaroyl] glucopyranosyl-2-(2-hydroxy)propyl-7-methoxy-5-methylchromone were completely assigned by 2D NMR observations. Especially the 1H assignments of the glucosyl and hydroxyl protons were achieved by utilizing HMQC, HMBC, 1H-1H COSY and DEPT techniques together with a heavy water exchange 1H NMR experiment.

Effect of rare earth on the microstructures and properties of a low expansion superalloy

A new Fe-Ni-Co-Nb-Ti-Si superalloy containing trace additions of selective rare earths and having good combination of very low thermal expansion coefficient, high-resistance to stress accelerated grain boundary oxygen embrittlement and fairly good notch-bar rupture strength has been successfully developed. The resistance to oxidation for long time exposure at high-temperatures and the stress rupture life has been improved significantly with trace yttrium addition. The microstructures of the alloys have been studied by means of analytical electron microscopy, chemical and X-ray analysis techniques. The results reveal that the trace yttrium segregates in the strengthening phase with platelet morphology, and helps in transforming A(3)B type epsilon phase into A(5)B type H. The morphology and crystal structures of the grain boundary phases also change with selective additions of rare earth elements. Compared with those in the conventional alloy, the platelet precipitates in the yttrium-containing alloy densely segregate within the grains and along the grain boundaries with smaller size. The segregation of the platelet precipitates within the grains is helpful in improving the strength of the alloy. In addition, its precipitation along the grain boundaries can improve the resistance to stress accelerated grain boundary oxidation and stress rupture property of the alloy and thereby contribute to its temperature stability.

Does race protect an oriental population from developing lipodystrophy in HIV-infected individuals on HAART?

OBJECTIVES

Lipodystrophy, hyperlipidaemia and hyperinsulinaemia are common metabolic complications of highly active antiretroviral therapy (HAART) in human immunodeficiency virus (HIV)-infected Caucasians. We questioned whether such complications also occur in other races.

METHODS

A cross-sectional analysis was performed in an outpatient clinic of a university teaching hospital with 156 Koreans, divided into HIV-infected subjects receiving HAART (n=57, group 1), HAART-naïve subjects (n=42, group 2), and healthy controls (n=57, group 3). Lipodystrophy was assessed by physical examination and questionnaire and body composition by dual-energy X-ray absorptiometry. Fasting triglyceride, total cholesterol, low-density (LDL) and high-density lipoprotein (HDL) cholesterol, free fatty acid (FFA), Apolipoprotein A1 (ApoA1), Apolipoprotein B (ApoB), glucose, insulin, c-peptide, leptin, cortisol, dehydroepiandrosterone (DHEA), CD4, CD8 lymphocyte counts and HIV RNA load were measured.

RESULTS

Lipodystrophy was observed in only 3.5% of HAART-treated HIV-infected Koreans. No statistical difference in regional fat accumulation or peripheral fat wasting was observed between groups 1, 2 and 3. No statistical difference in triglyceride, total cholesterol, LDL cholesterol, FFA, ApoA1, ApoB, glucose, insulin, C-peptide, leptin, cortisol, and DHEA were observed between groups 1, 2 and 3. HDL cholesterol was significantly lower in HIV-infected individuals compared to controls.

CONCLUSIONS

Lipodystrophy, hyperlipidaemia, and insulin resistance are rare metabolic complications of HAART in an oriental HIV-infected group of individuals. These findings warrant further race-specific metabolic complication studies in HIV-infected subjects receiving HAART.

Restoration of P-glycoprotein function is involved in the increase of natural killer activity with exogenous interleukin-15 in human immunodeficiency virus-infected individuals

A depressed level of natural killer (NK) activity is one of the various immunologic abnormalities in human immunodeficiency virus (HIV) infection. Interleukin-15 (IL-15), an immunotherapeutic candidate in HIV infection, increases NK activity and induces the excretion of CC-chemokines from divergent immune cells, but the mechanisms of NK activity enhancement by IL-15 stimulation is not clearly established in HIV infection. This study examined whether CC-chemokines, which are known to increase NK activity, are secreted adequately in HIV-infected individuals, and also investigated whether P-glycoprotein is involved in NK activity enhancement after IL-15 administration. NK activity increased with IL-15 stimulation in NK cells of HIV-infected individuals, as it does in normal NK cells. IL-15 stimulates NK cells to secrete CC-chemokines, such as, macrophage inflammatory protein-1alpha (MIP-1alpha), macrophage chemotactic protein-1alpha (MCP-1alpha) and regulated upon activation, normal T cells expressed and secreted (RANTES) in both HIV-infected individuals and controls with no significant difference. P-glycoprotein expression and function is decreased in HIV-infected individuals and restored only in NK cells of HIV-infected individuals after IL-15 stimulation. P-glycoprotein may play a role in the mechanism of increased NK cell activity in HIV-infected individuals after IL-15 stimulation.

Serologic and histopathologic study of Chlamydia pneumoniae infection in atherosclerosis: a possible pathogenetic mechanism of atherosclerosis induced by Chlamydia pneumoniae

Chronic infection and inflammation have recently been implicated as important etiologic agents for atherosclerosis in general and, in particular, ischemic heart disease. Several agents have been suggested as possible candidates for the chronic inflammation including cytomegalovirus, Helicobacter pylori and Chlamydia pneumoniae. We hypothesized that a vascular infection with C. pneumoniae may induce a chronic inflammatory reaction in the host vascular tissue and activated inflammatory cells may express inflammatory mediators such as cyclooxygenase-2 (COX-2) and matrix metalloproteinases (MMPs). At first, we evaluated the relationship between C. pneumoniae infection and atherosclerosis indirectly by serologic study, and then, to confirm our hypothesis, we performed an immunohistochemical study of atherosclerotic plaques. The seropositive rate of anti-Chlamydia pneumoniae IgG was higher in the disease group (Group I, 59.8%, n = 254) than in the negative control group (Group III, 47.4%, n = 97) (p = 0.041), but the anti-Chlamydia pneumoniae IgA was not different in seropositivity between the two groups (Group I, 64.6%; Group III, 57.7%). The simultaneous seropositive rates of both IgG and IgA were 56.7% in Group I and 43.3% in Group III (p = 0.033). In subgroups without the conventional risk factors of atherosclerosis, these findings were more prominent. Furthermore, we performed immunohistochemical staining on the atherosclerotic aortic tissues obtained from patients that were seropositive to C. pneumoniae (n = 5), by using antibodies to C. pneumoniae, COX-2, and MMP-9. The immunoreactivity for COX-2 and MMP-9 increased in the atherosclerotic plaques itself, predominantly in the surrounding area of immunoreactive C. pneumoniae. These findings support our hypothesis and C. pneumoniae may participate in a pathogenetic mechanism for atherogenesis or progression of atherosclerosis. The present study may open a promising perspective concerning future therapeutic trials of chronic inflammation related atherogenesis under pathophysiological conditions.

Spontaneous programmed cell death of peripheral blood mononuclear cells from HIV-infected persons is decreased with interleukin-15

Interleukin 15 (IL-15) is an important regulatory cytokine in cellular immunity. In vitro replacement of IL-15 has been shown to enhance immunity in Human immunodeficiency virus type 1 (HIV-1) infected lymphocytes. We evaluated the effect of IL-15 on the survival of peripheral blood mononuclear cells of HIV patients by examining in vitro lymphocyte apoptosis, and correlated the process with Bcl-2 and Fas gene regulation. Peripheral blood mononuclear cells (PBMC) from 21 HIV-infected adults and 24 HIV-seronegative healthy individuals were isolated and cultured to determine the effect of escalating doses of IL-15 (0, 1, 10, 100, 1000 ng/mL) on apoptosis. Lymphocyte proliferation assay with (3H) TdR was measured and Bcl-2 and Fas gene regulation was observed. The results were as follows: 1) IL-15 reduced culture induced lymphocyte apoptosis in HIV patients in a dose dependent manner, and reached a plateau level at a concentration of 100 ng/ml; 2) IL-15 significantly reduced the level of apoptosis after 3 days (14%) and 5 days (15%) of culture in HIV patients, while no difference was observed in HIV (-) donors; 3) The percentage of viable cells among the total number of lymphocytes was significantly enhanced by 25% in HIV patients with IL-15; 4) Bcl-2 expression was decreased in HIV patients (53.9 +/- 12.3%) compared to HIV (-) donors (93.0 +/- 3.7%), and IL-15 increased Bcl-2 expression by 21.2 +/- 5.2% in HIV patients; 5) Fas expression was increased in HIV patients (70.2 +/- 4.6%) compared to HIV (-) donors (32.4 +/- 4.3%), and IL-15 increased Fas expression by 8.4 +/- 1.2% in HIV (-) donors. Our findings indicate that IL-15 may influence immunologic abnormalities in HIV infection, particularly its ability to prevent apoptosis of lymphocytes by suppressing the down-modulation of Bcl-2. This may provide an experimental basis for IL-15 immunotherapy.

Antibodies to human T-cell lymphotropic virus type I (HTLV-I) by particle agglutination (PA) test in Korean blood donors

HTLV-I infection is a recently recognized disease entity that is common in some tropical and subtropical areas, including the southwestern district of Japan. Despite the geographical proximity and frequent cultural exchanges between Korea and Japan, it is understood that Korea is not an endemic area and HTLV-I-associated illnesses are very rare in Korea. This study was designed to evaluate the positive rate of anti-HTLV-I antibodies in Korean blood donors and its regional distribution. Sera were obtained from blood donors from various districts around Korea. Anti-HTLV-I antibodies were detected by using the microtiter particle agglutination test employing an indirect agglutination technique. A total of 9,281 donors were tested and 12 donors (0.13%) were positive for anti-HTLV-I antibodies, 10 (0.11%) out of 8,845 males and 2 (0.46%) out of 436 females, with relative female predominance. A relatively high incidence of anti-HTLV-I positive donors was observed in Cheju Island (0.80%), Kyungnam (0.31%), and Chonnam (0.15%). In conclusion, the positive rate of anti-HTLV-I antibodies seemed to be very low in Korea, but the highest positive rate of anti-HTLV-I antibodies was noticed on Cheju Island, warranting further research for confirmation.

Vancomycin-resistant enterococcal infections in Korea

Enterococci recently became the second-to-third most commonly isolated organism from nosocomial infections. Enterococci are intrinsically more resistant to many antimicrobial agents and often show acquired resistance to many antimicrobial agents including high-level aminoglycosides. With the increased use of vancomycin, vancomycin-resistant enterococci (VRE) has become an important nosocomial pathogen. In Korea, the proportion of VRE among all enterococcal of VRE is no longer low in some settings and recent observations of a sudden increase of VRE isolation in several hospitals in Korea suggests that VRE infection may become a serious problem in the near future. The most important considerations are that vancomycin-resistant genes may spread to other highly virulent genera, such as MRSA, and that there are no approved and convincingly effective antibiotics for the treatment of VRE. Therefore, current efforts have concentrated on limiting the spread of these organisms within the hospital environment. Prudent use of antimicrobial agents and strict adherence to preventive measures such as aggressive communication, education, and infection control practices are essential to control the spread of this organism. However, hospital infection control protocols and the laboratory support they require are costly in terms of space and supplies, as well as in personnel resources. These factors add further pressure to already stretched hospital budgets. Nevertheless, policies or programs defining and managing VRE infection or colonization should be established and now is the time to enforce an overall management strategy against VRE.

A case of primary bone lymphoma associated with acquired immunodeficiency syndrome

A 33-year old man with acquired immunodeficiency syndrome was admitted to Severance hospital following 1 year of diarrhea and 2 to 3 months of low sternal pain. The patient had progressive generalized lymphadenopathy for the previous 3 years. Whole body bone scan for evaluation of bone pain showed multiple abnormal hot uptakes at the low sternal body and T8 and T10 vertebra. Chest CT showed multifocal cortical erosion of the bone with soft tissue mass at the low sternal body and spine MRI showed multiple low-signal density in T1WI and high-signal density in T2WI at the T8 and T10 vertebral body. Biopsy was performed at the sternochondral junction and it showed high-grade malignant lymphoma of the large cell immunoblastic type. Immunostaining showed positive for the B-cell markers (CD79a and L26) and negative for the T-cell marker (UCHL1). Radiotherapy of 3,000 cGy was delivered to the sternum and vertebra. Since then, systemic chemotherapy with m-BACOD regimen (except dexamethasone) and anti-retroviral therapy with a combination of 3 drugs (didanosine, lamivudine, indinavir) has been performed. This is the first case report of primary bone lymphoma associated with acquired immunodeficiency syndrome in Korea.

Experimental study of microarterial autografts for repair of arterial defects with significant size discrepancy

On the basis of our years of clinical experience using the "unequal bite" suturing technique to perform end-to-end anastomosis of vessel with great discrepancy in diameter, an animal experimental study was performed in which an arterial defect, 1.0 to 1.4 mm in diameter, was reunited through the autogenous arterial graft, which was 0.3 to 0.4 mm in diameter. A high patency rate (95% in total) was obtained postoperatively. A small autogenous arterial graft may be used for repairing a large-caliber arterial defect clinically.

A new technique to anastomose vessels with great discrepancy in diameter

Free flap transfer often involves anastomosing vessels with different diameters. A new technique to anastomose vessels with considerable discrepancy in diameter, which has been used reliably for thirteen years in clinical practice, is described. Scanning electron microscopy shows that the anastomotic area is very smooth and heals well.

One-stage total reconstruction of the ear with simultaneous tympanoplasty

The one-stage total ear reconstruction (auricular reconstruction and tympanoplasty) has a number of merits. 1. Satisfactory esthetic results obtained in one operation. 2. The "super thin" skin flap is elevated on a plane that excludes hair follicles from the flap, so the hair-bearing areas of the scalp can be readily incorporated as part of the ear reconstruction. 3. The reconstructed ear has adequate blood supply and protective sensation. 4. The surgeon may choose to carry out a tympanoplasty and obtain restoration of auditory function or may choose to carry out a pseudomeatus procedure and reduce the operating time. We feel that the "super thin" skin flap and the simultaneous tympanoplasty are valuable supplements to ear reconstruction. The functional results of the tympanoplasty must be considered only a partial success at this time; long-term evaluation as well as technologic improvements are needed.

Double eyelid operations

The double eyelid in the Chinese population is a desirable physical feature, which is now increasingly popular and demands modern up-to-date aesthetic operations for its formation. The author describes 3 types of double eyelid operations, e.g., the ligation method, the incision method, and the skin grafting method. The advantages, disadvantages, and indications for each of these methods are evaluated and discussed. The creation of a double eyelid from an anatomic point of view is especially emphasized, with the illustrations of the anatomy and the operation made by the senior author.

Total reconstruction of the ear with auditory function: a two stage procedure

The rational treatment of severe microtia or anotia should be to restore not only the form but also the auditory function of the ear. To achieve this aim it is obvious that plastic surgeons must co-operate closely with an otologist: yet this degree of co-operation is seldom seen. This paper describes a two-stage procedure for total ear reconstruction with auditory function. In stage I, a tympanoplasty is performed before transplantation of the carved cartilage framework. Stage II consists of elevation of the reconstructed auricle and transplantation of a full-thickness skin graft to the post-auricular defect. Certain modifications of the operative techniques that we have found useful are discussed in detail.

The free thigh flap: a new free flap concept based on the septocutaneous artery

Based on the septocutaneous artery flap concept, the thigh, which is the commonest conventional donor site for split-skin grafts, can also become a donor area for skin flaps. The thigh flap, with its large and long neuro-vascular pedicle, can be used either as a free flap or as an island flap as an alternative to the lower abdominal flap, groin flap, tensor fasciae latae myocutaneous flap, sartorius myocutaneous flap or the gracilis myocutaneous flap. The anatomical basis, operative technique and characteristics of the thigh flap are discussed.