Clinical effects of use polymyxin B fixed on fibers in liver transplant patients with severe sepsis or septic shock

Clinical preparedness for severe pneumonia with highly pathogenic avian influenza A (H5N1): experiences with cases in Vietnam

BACKGROUND

Avian influenza A (H5N1) in human presents a global pandemic threat, and preparedness is urgently required in high-risk countries.

METHODS

A retrospective chart review was conducted on 8 patients with H5N1 infection (aged 2-30 years; 3 fatal) who were hospitalized in Bach Mai Hospital (BMH), Vietnam, or in affiliated hospitals with consultation by physicians in BMH between 2007 and 2010. Demographic background, chest radiographs, and clinical and laboratory data were evaluated to determine the critical issues in relation to clinical outcomes. Treatment of 4 patients with acute respiratory distress syndrome (ARDS) (2 fatal) was assessed for renal replacement therapy using continuous hemodiafiltration (CHDF), polymyxin B-immobilized (PMX) hemoperfusion, or their combination.

RESULTS

Patients had direct contact with dead/sick poultry infected with H5N1 virus or lived in areas where H5N1 poultry outbreaks had been reported at the same time as their illness. Time to initiation of oseltamivir from symptom onset was 2-6 days for survivors and 7-9 days for non-survivors. All patients except one had infiltrative shadows on chest radiographs on admission. Patients with delayed treatment developed ARDS. Renal replacement therapy contributed to patient survival, with improvement of oxygenation and a dramatic decrease in serum cytokine levels if initiated earlier.

CONCLUSIONS

Understanding local H5N1 poultry outbreaks and chest radiography assist early diagnosis and initiation of antiviral treatment. Developing a network among local and tertiary care hospitals can reduce the time to initiation of treatment. CHDF and PMX hemoperfusion are possible candidates for effective treatment of ARDS with H5N1 if applied earlier.

Role of apheresis and dialysis in pediatric living donor liver transplantation: a single center retrospective study

In the field of pediatric living donor liver transplantation, the indications for apheresis and dialysis, and its efficacy and safety are still a matter of debate. In this study, we performed a retrospective investigation of these aspects, and considered its roles. Between January 2008 and December 2010, 73 living donor liver transplantations were performed in our department. Twenty seven courses of apheresis and dialysis were performed for 19 of those patients (19/73; 26.0%). The indications were ABO incompatible-liver transplantation in 11 courses, fluid management in seven, acute liver failure in three, renal replacement therapy in two, endotoxin removal in two, cytokine removal in one, and liver allograft dysfunction in one. Sixteen courses of apheresis and dialysis were performed prior to liver transplantation for 14 patients. The median IgM antibody titers before and after apheresis for ABO blood type-incompatible liver transplantation was 128 and eight, respectively (P < 0.05). Eleven courses of apheresis and dialysis were performed post liver transplantation for 10 patients. The median PaO2/FiO2 ratio before and after dialysis for fluid overload was 159 and 339, respectively (P < 0.05). No bleeding or technical complications attributable to apheresis and dialysis occurred. The 1-year survival rate of the patients was 100%. Apheresis and dialysis in pediatric living donor liver transplantation are effective for antibody removal in ABO-incompatible liver transplantation, and fluid management for acute respiratory failure.

Adsorption of various antimicrobial agents to endotoxin removal polymyxin-B immobilized fiber (Toraymyxin®)

The presence/absence of adsorption of 9 representative types of antimicrobial agent used in combination with a polymyxin-B immobilized fiber (PMX-F) were determined and the degree of adsorption to PMX-F was quantitatively evaluated. Various antimicrobial agents were dissolved at appropriate concentrations, and PMX-F was added to each solution and incubated at 37°C. Antimicrobial solutions without PMX-F were also similarly incubated as controls. After 2 and 4h, the concentration of each antimicrobial agent was determined using HPLC. To produce an environment closer to the in vivo state, albumin or serum was added, and similar evaluation was performed. In the presence of albumin, the rate of adsorption to PMX-F was relatively high for Cefmetazon(®), Pentcillin(®), Ciproxan(®) and Zyvox(®). In the presence of serum, the adsorption rate was 4.02±2.83% for Pentcillin(®), 5.59±1.00% for Ciproxan(®), and 22.12±3.23% for Zyvox(®). The results of this study suggest that adequate caution is necessary on the clinical use of Zyvox(®), which was adsorbed in the presence of serum as an environment close to the in vivo environment, but the use of other antimicrobial agents in combination with PMX-F may have only slight influences on adsorption to PMX-F.

Galectin-3 is a negative regulator of lipopolysaccharide-mediated inflammation

Galectin-3 is a beta-galactoside-binding lectin that plays an important role in inflammatory diseases. It also interacts with the surface carbohydrates of many pathogens, including LPS. However, its role in infection is not fully understood. Data presented herein demonstrate for the first time that galectin-3 is a negative regulator of LPS-induced inflammation. Galectin-3 is constitutively produced by macrophages and directly binds to LPS. Galectin-3-deficient macrophages had markedly elevated LPS-induced signaling and inflammatory cytokine production compared with wild-type cells, which was specifically inhibited by the addition of recombinant galectin-3 protein. In contrast, blocking galectin-3 binding sites by using a neutralizing Ab or its ligand, beta-lactose, enhanced LPS-induced inflammatory cytokine expression by wild-type macrophages. In vivo, mice lacking galectin-3 were more susceptible to LPS shock associated with excessive induction of inflammatory cytokines and NO production. However, these changes conferred greater resistance to Salmonella infection. Thus, galectin-3 is a previously unrecognized, naturally occurring, negative regulator of LPS function, which protects the host from endotoxin shock but, conversely, favors Salmonella survival.

Silver as a residual disinfectant to prevent biofilm formation in water distribution systems

Biofilms can have deleterious effects on drinking water quality and may harbor pathogens. Experiments were conducted using 100 microg/liter silver to prevent biofilm formation in modified Robbins devices with polyvinyl chloride and stainless steel surfaces. No significant difference was observed on either surface between the silver treatment and the control.