Histamine h2 receptor signaling in the pathogenesis of sepsis: studies in a murine diabetes model

Poor treatment outcome and associated factors of hyperglycemic emergencies among diabetic patients in Ethiopia: A systematic review and meta-analysis

Background

Despite the fact that hyperglycemic crisis poses a significant threat to the health care systems of developing countries like Ethiopia, there is a dearth of reliable data regarding the poor treatment outcome and associated factors among hyperglycemic emergencies in Ethiopia. Therefore, this review aimed to assess poor treatment outcome and associated factors of hyperglycemic emergencies among diabetic patients in Ethiopia.

Methods

Published articles regarding poor treatment outcome and associated factors of hyperglycemic emergencies among diabetic patients in Ethiopia were extensively searched from PubMed, Google Scholar, Cochrane library, and African journal online. After extraction, data were exported to Stata software version 11 (Stata Corp LLC, TX, USA) for analysis. Statistically, the Cochrane Q-test and I2 statistics were used to determine the presence or absence of heterogeneity.

Results

3650 duplicates were eliminated from the 4291 papers (PubMed [18], Google scholar (1170), African journal online [21], and Cochrane library (3082)). The pooled estimate of poor treatment outcome among hyperglycemic emergencies in Ethiopia is found to be 16.21% (95% CI: 11.01, 21.41, P < 0.001). Creatinine level >1.2 mg/dl, stroke, sepsis and comorbidity were associated factors of poor treatment outcome.

Conclusion

Poor treatment outcome from hyperglycemic emergencies among diabetic patients was found to be high. Poor treatment outcome was predicted for those patients who had creatinine level >1.2 mg/dl, stroke, sepsis and comorbidity. As a result, we recommend healthcare providers to monitor thoroughly and have close follow-ups for patients with the identified predictors to improve poor treatment outcome from hyperglycemic crises.

Insight on Infections in Diabetic Setting

The correlation between diabetes mellitus and infectious diseases is widely recognized. DM patients are characterized by the impaired function of the immune system. This translates into the occurrence of a variety of infections, including urinary tract, skin and surgical site infections, pneumonia, tuberculosis, and, more recently, SARS-CoV-2. Hyperglycemia has been identified as a relevant factor contributing to unfavorable outcomes in hospitalized patients including SARS-CoV-2 patients. Several studies have been performed proving that to maintain the proper and stringent monitoring of glycemia, a balanced diet and physical activity is mandatory to reduce the risk of infections and their associated complications. This review is focused on the mechanisms accounting for the increased susceptibility of DM patients to infections, with particular attention to the impact of newly introduced hypoglycemic drugs in sepsis management.

Xenogeneic mesenchymal stem cell biocurative improves skin wounds healing in diabetic mice by increasing mast cells and the regenerative profile

Introduction

Diabetes mellitus (DM) is a chronic disease and a major cause of mortality and morbidity worldwide. The hyperglycemia caused by DM induces micro and macrovascular complications that lead, among other consequences, to chronic wounds and amputations. Cell therapy and tissue engineering constitute recent therapeutic alternatives to improve wound healing in diabetic patients. The current study aimed to analyze the effectiveness of biocuratives containing human mesenchymal stem cells (MSCs) associated with a hydrogel matrix in the wound healing process and related inflammatory cell profile in diabetic mice.

Methods

Biocuratives containing MSCs were constructed by 3D bioprinting, and applied to skin wounds on the back of streptozotocin (STZ)-induced type 1 diabetic (T1D) mice. The healing process, after the application of biocuratives with or without MSCs was histologically analyzed. In parallel, genes related to growth factors, mast cells (MC), M1 and M2 macrophage profiles were evaluated by RT-PCR. Macrophages were characterized by flow cytometry, and MC by toluidine blue staining and flow cytometry.

Results

Mice with T1D exhibited fewer skin MC and delayed wound healing when compared to the non-diabetic group. Treatment with the biocuratives containing MSCs accelerated wound healing and improved skin collagen deposition in diabetic mice. Increased TGF-β gene expression and M2 macrophage-related markers were also detected in skin of diabetic mice that received MSCs-containing biocuratives. Finally, MSCs upregulated IL-33 gene expression and augmented the number of MC in the skin of diabetic mice.

Conclusion

These results reveal the therapeutic potential of biocuratives containing MSCs in the healing of skin wounds in diabetic mice, providing a scientific base for future treatments in diabetic patients.

Impact of diabetes mellitus on outcomes of patients with sepsis: an updated systematic review and meta-analysis

BACKGROUND

The effect of concurrent diabetes on the outcome of sepsis is not conclusively known. A meta-analysis published in 2017 indicated that diabetes did not influence the mortality of patients with sepsis but increased the risk of acute renal injury. In view of publication of several new studies in recent years, there is a need for updated evidence.

METHODS

A systematic search was conducted using the PubMed, Scopus, Embase, and Google Scholar databases. Studies that were done in patients with sepsis, were observational in design- either cohort or case-control or analysed retrospective data were considered for inclusion. Statistical analysis was performed using STATA software.

RESULTS

A total of 21 studies were included. The risk of in-hospital mortality (RR 0.98, 95% CI 0.93, 1.04) and mortality at latest follow up i.e., within 90 days of discharge (RR 0.94, 95% CI 0.86, 1.04) among diabetic and non-diabetic subjects was statistically similar. There was an increased risk of in-hospital mortality among those with high blood glucose level at admission (RR 1.45, 95% CI 1.01, 2.09). Among those who were diabetic, the risk of acute renal failure (RR 1.54, 95% CI 1.34, 1.78) was higher than non-diabetics. The risk of respiratory failure, adverse cardiac events, need for additional hospitalization post-discharge and length of hospital stay was similar among diabetics and non-diabetics.

CONCLUSIONS

Diabetes is not associated with poor survival outcomes in patients with sepsis but is associated with increased risk of acute renal failure. High blood glucose levels, irrespective of the diabetes status, are associated with increased risk of in-hospital mortality. Findings underscore the need for better evaluation of renal function in diabetic patients with concurrent sepsis.

Glucagon Reduces Neutrophil Migration and Increases Susceptibility to Sepsis in Diabetic Mice

Sepsis is one of the most common comorbidities observed in diabetic patients, associated with a deficient innate immune response. Recently, we have shown that glucagon possesses anti-inflammatory properties. In this study, we investigated if hyperglucagonemia triggered by diabetes might reduce the migration of neutrophils, increasing sepsis susceptibility. 21 days after diabetes induction by intravenous injection of alloxan, we induced moderate sepsis in Swiss-Webster mice through cecum ligation and puncture (CLP). The glucagon receptor (GcgR) antagonist des-his1-[Glu9]-glucagon amide was injected intraperitoneally 24h and 1h before CLP. We also tested the effect of glucagon on CXCL1/KC-induced neutrophil migration to the peritoneal cavity in mice. Neutrophil chemotaxis in vitro was tested using transwell plates, and the expression of total PKA and phospho-PKA was evaluated by western blot. GcgR antagonist restored neutrophil migration, reduced CFU numbers in the peritoneal cavity and improved survival rate of diabetic mice after CLP procedure, however, the treatment did no alter hyperglycemia, CXCL1/KC plasma levels and blood neutrophilia. In addition, glucagon inhibited CXCL1/KC-induced neutrophil migration to the peritoneal cavity of non-diabetic mice. Glucagon also decreased the chemotaxis of neutrophils triggered by CXCL1/KC, PAF, or fMLP in vitro. The inhibitory action of glucagon occurred in parallel with the reduction of CXCL1/KC-induced actin polymerization in neutrophils in vitro, but not CD11a and CD11b translocation to cell surface. The suppressor effect of glucagon on CXCL1/KC-induced neutrophil chemotaxis in vitro was reversed by pre-treatment with GcgR antagonist and adenylyl cyclase or PKA inhibitors. Glucagon also increased PKA phosphorylation directly in neutrophils in vitro. Furthermore, glucagon impaired zymosan-A-induced ROS production by neutrophils in vitro. Human neutrophil chemotaxis and adherence to endothelial cells in vitro were inhibited by glucagon treatment. According to our results, this inhibition was independent of CD11a and CD11b translocation to neutrophil surface or neutrophil release of CXCL8/IL-8. Altogether, our results suggest that glucagon may be involved in the reduction of neutrophil migration and increased susceptibility to sepsis in diabetic mice. This work collaborates with better understanding of the increased susceptibility and worsening of sepsis in diabetics, which can contribute to the development of new effective therapeutic strategies for diabetic septic patients.

Harnessing the Power of Mast Cells in unconventional Immunotherapy Strategies and Vaccine Adjuvants

Mast cells are long-lived, granular, myeloid-derived leukocytes that have significant protective and repair functions in tissues. Mast cells sense disruptions in the local microenvironment and are first responders to physical, chemical and biological insults. When activated, mast cells release growth factors, proteases, chemotactic proteins and cytokines thereby mobilizing and amplifying the reactions of the innate and adaptive immune system. Mast cells are therefore significant regulators of homeostatic functions and may be essential in microenvironmental changes during pathogen invasion and disease. During infection by helminths, bacteria and viruses, mast cells release antimicrobial factors to facilitate pathogen expulsion and eradication. Mast cell-derived proteases and growth factors protect tissues from insect/snake bites and exposure to ultraviolet radiation. Finally, mast cells release mediators that promote wound healing in the inflammatory, proliferative and remodelling stages. Since mast cells have such a powerful repertoire of functions, targeting mast cells may be an effective new strategy for immunotherapy of disease and design of novel vaccine adjuvants. In this review, we will examine how certain strategies that specifically target and activate mast cells can be used to treat and resolve infections, augment vaccines and heal wounds. Although these strategies may be protective in certain circumstances, mast cells activation may be deleterious if not carefully controlled and any therapeutic strategy using mast cell activators must be carefully explored.

Medical Management of COVID-19: Evidence and Experience

Coronavirus disease 2019 is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and this infectious disease is termed COVID-19 in short. On a global scale, as of June 1, 2020, the World Health Organization (WHO) published statistics of 6,057,853 infected patients and 371,166 deaths worldwide. Despite reported observational data about the experimental use of certain drugs, there is no conclusively proven curative therapy for COVID-19 as of now; however, remdesivir received emergency use authorization (EUA) by the Food and Drug Administration (FDA) recently for use in patients hospitalized with COVID-19. There are several ongoing clinical trials related to the pharmacological choices of therapy for COVID-19 patients; however, drug trials related to observational studies so far have yielded mixed results and therefore have created a sense of confusion among healthcare professionals (HCPs). In this review article, we seek to collate and provide a summary of treatment strategies for COVID-19 patients with a variable degree of illness and discuss pharmacologic and other therapies intended to be used either as experimental medicine/therapy or as part of supportive care in complicated cases of COVID-19.

Role of Histamine in Modulating the Immune Response and Inflammation

Inflammatory mediators, including cytokines, histamine, bradykinin, prostaglandins, and leukotrienes, impact the immune system, usually as proinflammatory factors. Other mediators act as regulatory components to establish homeostasis after injury or prevent the inflammatory process. Histamine, a biogenic vasoactive amine, causes symptoms such as allergies and has a pleiotropic effect that is dependent on its interaction with its four histamine receptors. In this review, we discuss the dualistic effects of histamine: how histamine affects inflammation of the immune system through the activation of intracellular pathways that induce the production of inflammatory mediators and cytokines in different immune cells and how histamine exerts regulatory functions in innate and adaptive immune responses. We also evaluate the interactions between these effects.

Diabetes Mellitus and Sepsis: A Challenging Association

Sepsis is a life-threatening organ dysfunction caused by a deregulated host response to infection. This inappropriate response to micro-organism invasion is characterized by an overwhelmed systemic inflammatory response and cardiovascular collapse that culminate in high mortality and morbidity in critical care units. The occurrence of sepsis in diabetes mellitus (DM) patients has become more frequent, as the prevalence of DM has increased dramatically worldwide. These two important diseases represent a global public health concern and highlight the importance of increasing our knowledge of the key elements of the immune response related to both conditions. In this context, it is well established that the cells taking part in the innate and adaptive immune responses in diabetic patients have compromised function. These altered responses favor micro-organism growth, a process that contributes to sepsis progression. The present review provides an update on the characteristics of the immune system in diabetic and septic subjects. We also explore the beneficial effects of insulin on the immune response in a glycemic control-dependent and independent manner.

Effect of gastric acid suppressants and prokinetics on peritoneal dialysis-related peritonitis

AIM: To investigate the effect of gastric acid suppressants and prokinetics on peritonitis development in peritoneal dialysis (PD) patients.

METHODS: This was a single-center, retrospective study. The medical records of 398 PD patients were collected from January 2000 to September 2012 and analyzed to compare patients with at least one episode of peritonitis (peritonitis group, group A) to patients who never had peritonitis (no peritonitis group, group B). All peritonitis episodes were analyzed to compare peritonitis caused by enteric organisms and peritonitis caused by non-enteric organisms.

RESULTS: Among the 120 patients who met the inclusion criteria, 61 patients had at least one episode of peritonitis and 59 patients never experienced peritonitis. Twenty-four of 61 patients (39.3%) in group A and 15 of 59 patients (25.4%) in group B used gastric acid suppressants. Only the use of H2-blocker (H2B) was associated with an increased risk of PD-related peritonitis; the use of proton pump inhibitors, other antacids, and prokinetics was not found to be a significant risk factor for PD-related peritonitis. A total of 81 episodes of peritonitis were divided into enteric peritonitis (EP) or non-enteric peritonitis, depending on the causative organism, and gastric acid suppressants and prokinetics did not increase the risk of EP in PD patients.

CONCLUSION: The use of H2B showed a trend for an increased risk of overall PD-related peritonitis, although further studies are required to clarify the effects of drugs on PD-related peritonitis.