Immobilization of Clostridium perfringens type D in calcium alginate beads: toxin production mimics free cell culture

Background and Objectives: Cell-immobilization is used to maintain microbial culture to produce metabolites in repeat-ed-batch or continuous fermentations, thereby reducing the time and resources spent on delivering mass production of microbe. The technique also enables shortening of the detoxification phase and the amount of formaldehyde required due to low incidence of viable bacteria in the extract. Materials and Methods: A solution of sodium alginate containing Clostridium perfringens cells was dropped into stirring CaCl solution via a sterile syringe needle. Optimizations resulted in reasonably uniform beads containing C. perfringens. 2 Beads were externally stabilized by poly L-lysine, followed by immersion in a solution of Na-alginate to coat them with a new layer of alginate forming an alginate-PLL-alginate cortex. Results: This study proved successful in immobilizing C. perfringens cells inside uniform alginate microspheres. Cell load-ing and cell propagation inside the beads were measured. The cell loaded beads were cultivable in liquid media producing 550 minimum lethal doses per milliliter (MLD/ml) in a 72 h. Conclusion: The research paved the way for further investigations to optimize and establish an efficient bacterial encapsulation method. Thus, it seems possible to produce toxins from beads engulfing C. perfringens on larger scales via repeat-ed-batch or continuous fermentation processes. © 2022 The Authors. Published by Tehran University of Medical Sciences

Coronavirus disease 2019 in children with acute respiratory infection: A study from southeastern Iran

Background: Different aspects of coronavirus disease 2019 (COVID-19) in children have not been well understood so far. Objectives: In this paper, we reported the clinical, Paraclinical, and epidemiological features of the hospitalized children infected with COVID-19 in the southeast of Iran. Methods: This cross-sectional study was conducted in six hospitals affiliated to Kerman University of Medical Sciences. All children who were under the age of 15 years old hospitalized with acute respiratory infection from February 20 to May 14, 2020, were included in this study. Demographic characteristics, past medical history data, and disease-related data such as symptoms, signs, radiologic, and laboratory data were collected. Results: Of 97 hospitalized children with an acute respiratory infection, 13 cases (13.4) had been diagnosed to be infected by COVID-19. The mean (standard deviation) and median of age of the patients with COVID-19 were 68.0 (55.9) and 60 months, respectively. Fever (n = 11, 84.6), cough (n = 8, 61.5), respiratory distress (n = 5, 38.5), and gastrointestinal symptoms (n = 5, 38.5) were known as the most common symptoms in patients with COVID-19. Frequency fever (84.6 vs 47. 6, P = 0.016) and respiratory distress (38.8 vs 13.1, P = 0.022) were significantly higher in patients with COVID-19 compared to non-COVID individuals. Frequency of admission in the intensive care unit (38.5 vs. 27.4, P = 0.668) and death rate (15.4 vs. 7.1, P = 0.291) were higher in patients with COVID-19 compared to non-COVID-19 subjects, but there were no significant differences between the two groups in term of these variables. Conclusions: A low proportion of children hospitalized with acute respiratory syndrome were infected by COVID-19. Most of the children with COVID-19 recovered with supportive care with no need for any specific treatment. © 2020, Author(s)

[Multimodal treatment for acute antibody-mediated renal transplant rejection: successful rescue therapy with combined plasmapheresis, photopheresis and intravenous immunoglobulin].

The fundamental role of antibodies in the development of acute graft rejection has been established recently. Antibody-mediated acute rejection may develop at any time during the post-transplant period. Several therapeutic approaches have been proposed in the last decades. However, there is no standardized therapy. The aim of this study is to report the Sapienza University experience of combined plasma treatment and high-dose intravenous immunoglobulin ± extracorporeal photopheresis. From January 2006 to September 2009, 6 patients were treated at Sapienza University. In 5 cases (83%) complete regression of the acute rejection was observed, followed by stable renal function (median creatinine value at 1-year follow-up: 1.5 mg/dL). No adverse events were reported. Our approach seems to give good results in terms of graft survival and procedure safety. Further studies on a larger number of patients will be needed to confirm the validity of these findings. Moreover, comparison between our protocol and other treatments is necessary

Immuno-hematological monitoring after allogeneic stem cell transplantation. A single-center, prospective study of 104 patients

Background - The impact of ABO incompatibility on the outcome of hematopoietic stem cell transplantation (HSCT) is still debated. We report the results of a prospective, single-center study evaluating the impact of ABO mismatch on the development of immediate and late immuno-hematological complications, and the efficacy of the protocol used at the "Sapienza" University (Rome, Italy) to manage ABO incompatibility in patients undergoing HSCT.Materials and methods - From January 2013 to December 2016, we prospectively analyzed all patients undergoing HSCT. Graft manipulation or desensitization strategies were used according to ABO incompatibility, donor sex and donor transfusion history. Red blood cell and platelet transfusions were given based on immunohematological features.Results - From January 2013 to December 2016, 104 consecutive patients underwent HSCT from a matched related donor (29.81%), matched unrelated donor (53.58%), cord blood (1.9%) or haploidentical donor (14.42%). Forty-nine patients (47%) were ABO-identical and 55 (53%) ABO-incompatible (23 major, 25 minor, 7 bidirectional). Donor engraftment, graft failure or other complications did not differ between ABO compatible or incompatible patients. ABO incompatibility did not show a significant impact on graft-versus-host disease, overall survival or disease-free survival. Factors associated with the need for prolonged red blood cell support were ABO incompatibility (p=0.0395), HLA disparity between donor and recipient (p=0.004) and the onset of hemorrhagic cystitis (p=0.015). In multivariate analysis HLA disparity was the only statistically significant condition (p=0.004).Discussion - ABO incompatibility does not represent a barrier to allogeneic HSCT. It is, however, associated with prolonged transfusion requirements. Close immunohematological monitoring, as a shared standard procedure, allows appropriate transfusion support to be provided and limits post-HSCT immuno-hematological complications

A good manufacturing practice method to ex vivo expand natural killer cells for clinical use.

Great interest has been raised recently by the design of new adoptive immunotherapeutic strategies based on the in vivo infusion of ex vivo-expanded and activated natural killer (NK) cells. The development of good manufacturing practice (GMP) methods for the efficient production of fully functional NK cells is mandatory for clinical application. MATERIALS AND METHODS: Peripheral blood mononuclear cells were obtained by leukapheresis and processed in the GMP facility. For NK-cell enrichment, a two-step immunomagnetic procedure consisting of CD3+ T-cell depletion followed by CD56+ cell positive selection was used. Isolated NK cells were suspended in serum-free medium containing autologous plasma, interleukin (IL)-2 and IL-15 in the presence of irradiated autologous feeder cells and cultured for 14 days at 37 °C. IL-2 and IL-15 were also added during the last 24 hours of culture. Expanded cells underwent full quality control testing for cytogenetic characteristics, viability, sterility, phenotype and endotoxin status; functional tests, such as degranulation assays and cytotoxicity, were performed on expanded NK cells before cryopreservation and after thawing. RESULTS: NK-cell populations expanded on average 15.7±4.7 fold by day 14, with a viability of 96% ±0.5. At the end of the incubation period, 97% ±1.1 of the expanded population was CD56+ NK cells; these effector cells showed significant up-regulation of the activating receptors NKG2D and DNAM-1. Functional tests demonstrated that expanded NK cells are fully functional with no difference whether tested before cryopreservation or after thawing. DISCUSSION: These data provide the basis for developing new NK-cell-based immunotherapeutic strategies for the treatment of patients with cance