CEST MRI of sepsis‐induced acute kidney injury

Sepsis‐induced acute kidney injury (SAKI) is a major complication of kidney disease associated with increased mortality and faster progression. Therefore, the development of imaging biomarkers to detect septic AKI is of great clinical interest. In this study, we aimed to characterize the endogenous chemical exchange saturation transfer (CEST) MRI contrast in the lipopolysaccharide (LPS)‐induced SAKI mouse model and to investigate the use of CEST MRI for detecting such injury. We used a SAKI mouse model that was generated by i.p. injection of 10 mg/kg LPS. The resulting kidney injury was confirmed by the elevation of serum creatinine and histology. MRI assessments were performed 24 h after LPS injection, including CEST MRI at different B₁ strengths (1, 1.8 and 3 μT), T₁ mapping, T₂ mapping and conventional magnetization transfer contrast (MTC) MRI. The CEST MRI results were analyzed using Z‐spectra, in which the normalized water signal saturation (S_sat/S₀) is measured as a function of saturation frequency. Substantial decreases in CEST contrast were observed at both 3.5 and ? 3.5 ppm frequency offset from water at all B₁ powers, with the most significant difference obtained at a B₁ of 1.8 μT. The average S_sat/S₀ differences between injured and normal kidneys were 0.07 (0.55 ± 0.04 versus 0.62 ± 0.04, P = 0.0028) and 0.07 (0.50 ± 0.04 versus 0.57 ± 0.03, P = 0.0008) for 3.5 and ? 3.5 ppm, respectively. In contrast, the T₁ and T₂ relaxation times and MTC contrast in the injured kidneys did not show a significant change compared with the normal control. Our results showed that CEST MRI is more sensitive to the pathological changes in injured kidneys than the changes in T₁, T₂ and MTC effect, indicating its potential clinical utility for molecular imaging of renal diseases.     

Implementation of a protocol proposed by the Brazilian National Health Surveillance Agency for antibiotic use in very low birth weight infants

ObjectiveTo analyze the implementation of a protocol proposed by the Brazilian National Health Surveillance Agency (Agência Nacional de Vigilância Sanitária – ANVISA) to improve sepsis diagnosis in very low birth weight newborns.MethodsThis was a prospective study that evaluated the implementation of a protocol involving clinical and laboratory criteria (hematologic scoring system of Rodwell and C-reactive protein serial measurements), recommended by ANVISA, to improve the diagnosis of neonatal sepsis in very low birth weight newborns. The study included all patients who were born and remained in the neonatal intensive care unit until discharge or death, and excluded those with congenital diseases. The main outcomes measured in newborns before (2006-2007) and after implementation of the protocol (2008) were the rates of early and late-onset sepsis, use of antibiotics, and mortality. Means were compared by Student's t-test and categorical variables were compared by the chi-squared test; the significance level for all tests was set at 95%.ResultsThe study included 136 newborns with very low birth weight. There was no difference between groups regarding general clinical characteristics in the studied periods. There was, however, a decrease in the number of diagnoses of probable early-onset sepsis (p < 0.001), use of antimicrobial regimens (p < 0.001), and overall mortality and infection-related mortality (p = 0.009 and p = 0.049, respectively).ConclusionThe implementation of the protocol allowed improvement of sepsis diagnosis by reducing the diagnosis of probable early-onset sepsis, thus promoting efficient antimicrobial use in this population.     

A clinical and microbiological study of puerperal sepsis in a tertiary care hospital in India

Objective: This prospective study was carried out to evaluate the clinical profile and bacterial isolates among women with puerperal sepsis in a tertiary hospital in North India.

Materials and methods: Women with puerperal sepsis (n?=?45) admitted from January 2015 to April 2016 were followed prospectively. Cultures were obtained from cervix, blood, urine, and pyoperitoneum. Initial antibiotics were cefotaxime or piperacillin with tazobactam plus amikacin plus clindamycin or metronidazole and were changed according to sensitivity.

Results: Out of 7887 deliveries during this period, 45 (0.2%) women had puerperal sepsis. 16 (35.5%) delivered in the present hospital, 25 (55.5%) at another health care facility, and 4 (8.9%) at home. Delivery was by cesarean section (CS) in 24/45 (53.3%) and vaginal in 21/45 (46.6%). Grade 1 sepsis occurred in 21, grade 2 in two, and grade 3 in 22 women. Majority (29/45 or 64.5%) had no risk factor for puerperal sepsis. There were two (4.4%) deaths and 13/45 (28.8%) had near-miss morbidity. Pathogenic bacteria were isolated in 33/45 (73.3%) in cervical swab (69%), blood, urine, or pus culture with no significant difference in the bacterial yield or species isolated between cotton or polyester swabs (p?>?.05). Escherichia coli were the commonest isolate and was sensitive to amikacin in all. Five had stillbirths and 4/40 neonates developed sepsis but recovered.

Conclusions: Escherichia coli was the commonest pathogen and was uniformly sensitive to amikacin, which may be included among the initial antibiotics to treat puerperal sepsis in India.     

脓毒症小鼠血清HMGB1与心肌损伤程度、炎症相关因子、BNP及cTnI水平的关系

目的 探讨血清高迁移率族蛋白B1(high mobility group box 1,HMGB1)在脓毒症小鼠心肌损伤中的作用及与心肌细胞炎症因子、血清B型钠尿肽(B-type natriuretic peptide,BNP)和肌钙蛋白(troponin,cTnI)的相关性。 方法 本研究选取6～8周龄、SPF级的昆明系小鼠60只,采用随机数字表法分为模型组、假手术组各30只,采用小鼠盲肠结扎穿孔法建立脓毒症小鼠模型,观察不同时间点小鼠血清HMGB1的水平变化,探讨其与心肌细胞凋亡率、心肌细胞炎症因子、血清B型钠尿肽(BNP)和肌钙蛋白(cTnI)的相关性。 结果 在0 h时刻,模型组和假手术组的血清HMGB1水平、心肌细胞凋亡率差异无统计学意义(P>0.05);在造模后12、24、48及72 h,模型组小鼠的血清HMGB1水平、心肌细胞凋亡率显著高于假手术组,差异均有统计学意义(P<0.05);在造模后48 h,模型组心肌组织中肿瘤坏死因子(tumor necrosis factor-α,TNF-α)、白细胞介素-6(interleukin-6,IL-6)、IL-10、血清BNP、血清cTnI水平显著高于假手术组(P<0.05);在造模后48 h,模型组心肌组织中TNF-α、IL-6、IL-10、血清BNP、血清cTnI水平与血清HMGB1均呈显著正相关(P<0.05)。 结论 血清HMGB1在脓毒症小鼠中水平升高趋势明显,并且与小鼠心肌损伤具有密切的关系。     

Vitamin D Level and Risk of Community-Acquired Pneumonia and Sepsis

Previous research has reported reduced serum 25-hydroxyvitamin D (25(OH)D) levels is associated with acute infectious illness. The relationship between vitamin D status, measured prior to acute infectious illness, with risk of community-acquired pneumonia (CAP) and sepsis has not been examined. Community-living individuals hospitalized with CAP or sepsis were age-, sex-, race-, and season-matched with controls. ICD-9 codes identified CAP and sepsis; chest radiograph confirmed CAP. Serum 25(OH)D levels were measured up to 15 months prior to hospitalization. Regression models adjusted for diabetes, renal disease, and peripheral vascular disease evaluated the association of 25(OH)D levels with CAP or sepsis risk. A total of 132 CAP patients and controls were 60 ± 17 years, 71% female, and 86% Caucasian. The 25(OH)D levels <37 nmol/L (adjusted odds ratio (OR) 2.57, 95% CI 1.08–6.08) were strongly associated with increased odds of CAP hospitalization. A total of 422 sepsis patients and controls were 65 ± 14 years, 59% female, and 91% Caucasian. The 25(OH)D levels <37 nmol/L (adjusted OR 1.75, 95% CI 1.11–2.77) were associated with increased odds of sepsis hospitalization. Vitamin D status was inversely associated with risk of CAP and sepsis hospitalization in a community-living adult population. Further clinical trials are needed to evaluate whether vitamin D supplementation can reduce risk of infections, including CAP and sepsis.     

miR-16在金黄色葡萄球菌脓毒症中的表达及意义探讨

目的探讨miR-16表达水平与金黄色葡萄球菌脓毒症严重程度的关联性,进一步探讨其潜在的临床意义。方法收集金黄色葡萄球菌脓毒症血液标本共计32例,脓毒性休克、严重脓毒症和一般脓毒症各8例,不同年龄段的健康对照24例;另外,收集革兰氏阴性菌脓毒症血液标本8例。用Trizol液裂解全血后提取microRNA,采用荧光定量PCR测定miR-16在不同组的表达水平(2-△△Ct法),用SPSS 13.0软件分析各组之间的统计学差异。采用SPSS 13.0软件将miR-16定量值与相应CRP和PCT值进行相关性分析。结果 miR-16表达水平与金黄色葡萄球菌脓毒症严重程度呈明显的负关联,各实验组与对照组相比均有统计学差异(P0.001),实验组之间也有统计学差异(P0.01)。miR-16表达水平与CRP和PCT值呈负相关性,相关系数分别为-0.561和-0.769。结论 miR-16表达与金黄色葡萄球菌脓毒症有明显的负关联性,提示其可能作为该菌脓毒症严重程度的标记物。