Diagnostic performance of a multiplexed gastrointestinal PCR panel for identifying diarrheal pathogens in children undergoing hematopoietic stem cell transplant.

BACKGROUND: Diarrhea is a common complication of hematopoietic stem cell transplantation (HSCT) and is associated with substantial morbidity, but its etiology is often unknown. Etiologies of diarrhea in this population include infectious causes, chemotherapy- or medication-induced mucosal injury and graft-versus-host disease (GVHD). Distinguishing these potential causes of diarrhea is challenging since diarrheal symptoms are often multifactorial, and the etiologies often overlap in transplant patients. The objectives of this study were to evaluate whether the FilmArray gastrointestinal (GI) panel would increase diagnostic yield and the degree to which pre-transplantation colonization predicts post-transplantation infection. METHODS: From November 2019 to February 2021, a total of 158 patients undergoing HSCT were prospectively included in the study. Stool specimens were obtained from all HSCT recipients prior to conditioning therapy, 28 ± 7 days after transplantation and at any new episode of diarrhea. All stool samples were tested by the FilmArray GI panel and other clinical microbiological assays. RESULTS: The primary cause of post-transplantation diarrhea was infection (57/84, 67.86%), followed by medication (38/84, 45.24%) and GVHD (21/84, 25.00%). Ninety-five of 158 patients were colonized with at least one gastrointestinal pathogen before conditioning therapy, and the incidence of infectious diarrhea was significantly higher in colonized patients (47/95, 49.47%) than in non-colonized patients (10/63, 15.87%) (P < 0.001). Fourteen of 19 (73.68%) patients who were initially colonized with norovirus pre-transplantation developed a post-transplantation norovirus infection. Twenty-four of 62 (38.71%) patients colonized with Clostridium difficile developed a diarrheal infection. In addition, FilmArray GI panel testing improved the diagnostic yield by almost twofold in our study (55/92, 59.78% vs. 30/92, 32.61%). CONCLUSIONS: Our data show that more than half of pediatric patients who were admitted for HSCT were colonized with various gastrointestinal pathogens, and more than one-third of these pathogens were associated with post-transplantation diarrhea. In addition, the FilmArray GI panel can increase the detection rate of diarrheal pathogens in pediatric HSCT patients, but the panel needs to be optimized for pathogen species, and further studies assessing its clinical impact and cost-effectiveness in this specific patient population are also needed.

Changes in body composition in children with acute graft-versus-host disease within the first 100 days after hematopoietic stem cell transplantation.

BACKGROUND: Acute graft-versus-host-disease (aGVHD) is one of the main complications of hematopoietic stem cell transplantation (HSCT). This study investigated the changes in body composition of pediatric patients with aGVHD during the first 100 days after HSCT. METHODS: Fifty-five children receiving HSCT were divided into two groups (aGVHD and non-aGVHD). Body mass index Z-scores (BMI-z), arm muscle area index (AMAI), fat mass index (FMI), and fat-free mass index (FFMI) were measured on the day of transplantation (H0), and on the 30th (H30), 60th (H60), and 100th day (H100) after the transplantation. The correlative factors on body composition were evaluated. RESULTS: In the aGVHD group, the rates of absolute change of BMI-z at H30, H60, and H100 showed a significant increase as compared to that at H0, especially at H30 which was remarkably higher than that of the non-aGVHD group (P = 0.008). AMAI showed a continuous decrease from H0 to H100 in the aGVHD group; also FFMI was found to be lower than that of the non-aGVHD group during the first 100 days after transplantation, however, no significant differences were found between the two groups. At H60 and H100, FFMI in the aGVHD group was lower than that in the non-aGVHD group (P = 0.014, P = 0.032, respectively). Glucocorticoid treatment and the occurrence of mucositis were the key factors for changes in body composition in the aGVHD group. CONCLUSIONS: Changes in body composition are characterized by a lean reduction in body mass and increase in adipose tissues in the early stage of post-transplantation in the aGVHD children. Glucocorticoid treatment and occurrence of mucositis are the two important factors that were found to affect body composition after HSCT.

Vitamin K1 distribution following intravenous vitamin K1-fat emulsion administration in rats.

This study investigated vitamin K1 (VK1 ) distribution following intravenous vitamin K1-fat emulsion (VK1 -FE) administration and compared it with that after VK1 injection. Rats were intravenously injected with VK1-FE or VK1 . The organ and tissue VK1 concentrations were determined using high-performance liquid chromatography method at 0.5, 2 and 4 h to determine distribution, equilibrium and elimination phases, respectively. In the VK1-FE group, the plasma, heart and spleen VK1 concentrations decreased over time. However, other organs like liver, lung, kidney, muscle and testis, reached peak VK1 concentrations at 2 h. In the VK1 injection group, the liver VK1 concentrations were significantly higher than those in other organs at the three time points. However, VK1 concentrations in the other organs peaked at 2 h. In addition, in VK1-FE group, the heart, spleen and lung VK1 concentrations were significantly higher than those in the VK1 injection group at the three time points, and the liver VK1 concentration was significantly higher than that in the VK1 injection group at 4 h. The VK1 amount was greatest in the liver compared with the other organs. Thus, the liver is the primary organ for VK1 distribution. The distribution of VK1 is more rapid when injected as VK1-FE than as VK1 .

Molecular epidemiological characteristics of Streptococcus pyogenes strains involved in an outbreak of scarlet fever in China, 2011.

OBJECTIVE: To investigate molecular characterization of streptococcus pyogenes isolates involved in an outbreak of scarlet fever in China in 2011. METHODS: Seventy-four Streptococcal pyogenes involved in an outbreak of scarlet fever were isolated from pediatric patients in the areas with high incidence in China from May to August of 2011. Emm genotyping, pulsed-field gel electrophoresis (PFGE), superantigen (SAg) genes and antimicrobial susceptibility profiling were analyzed for these isolates. RESULTS: A total of 4 different emm types were identified. Emm12 was the most prevalent type which contained four predominating PFGE patterns corresponding to four different virulence and superantigen profiles. Emm12 (79.7%) and emm1 (14.9%) accounted for approximately 94% of all the isolates. The speA gene was all negative in emm12 isolates and positive in emm1 isolates. All strains were resistant to erythromycin, and 89.4% of them were resistant to erythromycin, tracycline, and clindamycin simultaneously. CONCLUSION: Several highly diversified clones with a high macrolide resistance rate comprise a predominant proportion of circulating strains, though no new emm type was found in this outbreak. The data provide a baseline for further surveillance of scarlet fever, which may contribute to the explanation of the outbreak and development of a GAS vaccine in China.

The effects of Chinese yam-epimedium mixture on respiratory function and quality of life in patients with chronic obstructive pulmonary disease.

OBJECTIVE: To examine the clinical effects of a mixture of Chinese Yam and epimedium in patients with stable moderate or severe chronic obstructive pulmonary disease (COPD). METHODS: Forty-nine patients with COPD were randomly allocated to a group whose usual treatment was supplemented with oral Chinese yam-epimedium mixture, or a control group given placebo. For each patient, body mass index, airflow obstruction, dyspnea, and exercise capacity were measured and converted into the BODE index before treatment and at one and three months after initiation of treatment. Participants also completed the St. George's respiratory questionnaire (SGRQ) at the same intervals. RESULTS: After one month, improvements were seen in the BODE index and SGRQ of participants taking Chinese yam-epimedium mixture compared to controls. There were statistically significant differences in the SGRQ: three of its components and the total SGRQ scores were significantly decreased (P < 0.05), respiratory symptom scores had improved (P < 0.01), and the dyspnea component of the BODE index had significantly decreased (P < 0.05). Similar improvements were observed after three months of treatment, but exercise tolerance had also improved: the six-minute walking distance had significantly increased (P < 0.05) in the treatment group when compared with controls. CONCLUSION: Chinese yam-epimedium mixture can significantly improve dyspnea, exercise capacity, and the quality of life of patients with stable moderate or severe COPD.

Production and immunoanalytical application of 32 monoclonal antibodies against metacestode somatic antigens of Echinococcus multilocularis.

Alveolar echinococcosis is a rare but potentially fatal disease. Immunodiagnosis based on antibodies or antigens plays an important role in its diagnosis. In this study, metacestode somatic antigens of Echinococcus multilocularis were used to immunize BALB/c mice, and hybridomas were formed by cell fusion. Making use of the inherent effect of monoclonal antibody techniques to isolate different epitopes, we obtained a repertoire of 32 monoclonal antibodies against the metacestode somatic antigens. These monoclonal antibodies were used to investigate the specificity and localization of the metacestode antigens by enzyme-linked immunosorbent assay and immunohistochemistry, respectively. Nine antibodies specifically reacted with E. multilocularis, while 14 and ten cross-reacted with Echinococcus granulosus and Taenia saginata, respectively. Twenty-five antibodies stained the laminated layer. Eight reacted with the tegument of the protoscolex. Fourteen antibodies recognized the germinal layer. Most of the monoclonal antibodies can react with the antigen Em2. One antibody can react with antigen Em2 and Em10. One antibody that cross-reacted with T. saginata stained the germinal layer and protoscolex, especially its hooklets and suckers, but could not react with Em2 and Em10 antigens. It detected protein bands at 26 and 52 kDa. Two E. multilocularis-specific monoclonal antibodies stained both the germinal and laminated layers and could be used not only to purify specific antigens but also for immunohistochemical studies of E. multilocularis. In summary, these 32 monoclonal antibodies could have potential applications as useful tools in further studies of E. multilocularis antigen profiles.

Effect of explosive noise on gastrointestinal transit and plasma levels of polypeptide hormones.

AIM: To investigate the effect of firing noise on gastrointestinal transit and probe its mechanism by measuring the levels of plasma polypeptide hormones. METHODS: A total of 64 SD rats were randomly divided into a control group and three stimulating groups. Firing noise of different intensity by sub-machine guns was used as inflicting factor. The effect of firing noise on liquid substance gastrointestinal transit and solid substance gastrointestinal transit was observed by measuring the ratio of carbon powder suspension transmitting and barium sticks transmitting respectively. Plasma levels of polypeptide hormones were measured by radio-immunoassay. RESULTS: The noise accelerated gastrointestinal transit of solid food by more than 80 db;and accelerated gastrointestinal transit of liquid food significantly by more than 120 db. Meantime, plasma levels of plasma motilin (MTL)(157.47+/-16.08; 151.90+/-17.08), somatostatin (SS)(513.97+/-88.77; 458.25+/-104.30), substance P (SP)(115.52+/-20.70; 110.28+/-19.96) and vasoactive intestinal peptide (VIP) (214.21+/-63.17; 251.76+/-97.24) remarkably changed also. CONCLUSION: Within a certain intensity range, the firing noise changes the levels of rat plasma gastrointestinal hormones, but the gastrointestinal transit is still normal. Beyond the range, the noise induces plasma hormone levels disturbance and gastrointestinal transit disorder.