Preperitoneal pelvic balloon tamponade-an effective intervention to control pelvic injury hemorrhage in a swine model.

Objective: This study aimed to estimate the effects of the volume of preperitoneal balloon (PPB) on arterial and venous hemorrhage in a swine pelvic fracture model. Methods: Twenty-four swine were randomized into 0-mL, 500-mL, 800-mL, and 1000-mL intra-hematoma PPB groups. They were subjected to open-book pelvic fracture and reproducible injuries in the external iliac artery and vein. The pelvic binder and IH-PPBs with different volumes of fluid were applied to control the active hemorrhage after arterial and venous injuries. The survival time and rate during 60-min observation and digital subtraction angiography (DSA) images were the primary endpoints in this study. Secondary endpoints included survival rate within 70 min, peritoneal pressure, hemodynamics, blood loss, infusion fluid, blood pH, and lactate concentration. Results: Our results indicated that the 800-mL and 1000-mL groups had a higher survival rate (0%, 50%, 100% and 100% for 0, 500, 800, and 1000-mL groups respectively; p < 0.0001) and longer survival time (13.83 ± 2.64, 24.50 ± 6.29, 55.00 ± 6.33, and 60.00 ± 0.00 min for 0, 500, 800, and 1,000 groups respectively; p < 0.0005) than the 0-mL or 500-mL groups during the 60 min observation. Contrastingly, survival rate and time were comparable between 800-mL and 1000-mL groups during the 60-min observation. The IH-PPB volume was associated with an increase in the pressure of the balloon and the preperitoneal pressure but had no effect on the bladder pressure. Lastly, the 1000-mL group had a higher mean arterial pressure and systemic vascular resistance than the 800-mL group. Conclusion: IH-PPB volume-dependently controls vascular bleeding after pelvic fracture in the swine model. IH-PPB with a volume of 800 mL and 1000 mL efficiently managed pelvic fracture-associated arterial and venous hemorrhage and enhanced survival time and rate in the swine model without evidences of visceral injury.

RESUSCITATIVE RECTAL BALLOON COMPRESSION COMBINED WITH PELVIC BINDER EFFICIENTLY CONTROLLED FATAL VENOUS HEMORRHAGE IN A HEMODYNAMICALLY UNSTABLE PELVIC FRACTURE CANINE MODEL.

ABSTRACT: Objective: This study evaluated the feasibility of a combination of pelvic binder and rectal balloon compression in managing fatal venous hemorrhage in a canine model of pelvic fracture. Methods: Rectums from humans (rectal cancer patients), swine, and canines were retrieved to determine their elasticity by measuring their stress and strain. Canines were selected as the animal model in this study because their rectum demonstrated more reversible strain than swine rectum. Doppler ultrasound was used to assess the effect of rectal balloon volume on the blood flow of pelvic iliac blood vessels in three canines. A rectal balloon of 250 mL was chosen to control pelvic venous bleeding as it could provide a peak effect in reducing the blood flow of bilateral internal iliac veins. Then, the open-book pelvic fracture with fatal bleeding of both internal iliac veins animal model was built. The animals were divided into four groups after the modeled surgery to undergo no treatment, pelvic binder, rectal balloon compression, or a combination of pelvic binder and rectal balloon compression. The treatment efficacy was evaluated based on their survival time, survival rate, blood loss, bleeding rate, infusion rate, blood pH, lactate concentration, the stability of hemodynamics, blood loss, and fluid infusion volume. Results: Our results showed that after the reproducible injuries in both internal iliac veins, the combination of pelvic binder and rectal balloon compression was associated with the best survival rate and survival time compared with the other treatment groups. In addition, the combination of pelvic binder and rectal balloon compression exhibited more stable hemodynamics than the pelvic binder or rectal balloon compression treatment alone. Conclusions: This study demonstrated the potential feasibility of using pelvic binder combined with rectal balloon compression to manage the fatal venous bleeding in pelvic fractures.

Extracellular ATP released by copper stress could act as diffusible signal in alleviating the copper stress-induced cell death.

In the present work, by using tobacco cell suspension and wheat seedlings, we studied that eATP (extracellular ATP) released by copper (Cu) stress could act as diffusible signal in alleviating the Cu stress-induced cell death. A semipermeable membrane was fixed in the middle of a plastic box to divide the box into two equal compartments (A and B, respectively). This semipermeable membrane can prevent direct cell-to-cell (or seedling-to-seedling) contact and the diffusion of the macromolecules [such as ATPase (adenosine 5'-triphosphatase)] between these two compartments. The cell suspension directly stressed with CuCl2 was placed in compartment A and was incubated with the untreated cell suspension in compartment B. Such treatment significantly increased the levels of cell death and eATP content of the cell suspension in these two compartments. In contrast, addition of ATPase into the cell suspension directly stressed with CuCl2 decreased the eATP level in these two compartments but further increased the level of cell death in compartment B, compared to no addition of ATPase. Similar results were obtained when tobacco cell suspension was replaced by wheat seedlings. These observations indicate that when Cu stress from compartment A induced the plant cell death in compartment B, ATP transferred from compartment A could play a role in alleviating this cell death. Thus, it is suggested that eATP released by copper stress could act as diffusible signal in alleviating the Cu stress-induced cell death.

Extracellular ATP: a potential regulator of plant cell death.

Adenosine 5'-triphosphate (ATP) has been regarded as an intracellular energy currency molecule for many years. In recent decades, it has been determined that ATP is released into the extracellular milieu by animal, plant and microbial cells. In animal cells, this extracellular ATP (eATP) functions as a signalling compound to mediate many cellular processes through its interaction with membrane-associated receptor proteins. It has also been reported that eATP is a signalling molecule required for the regulation of plant growth, development and responses to environmental stimuli. Recently, the first plant receptor for eATP was identified in Arabidopsis thaliana. Interestingly, some studies have shown that eATP is of particular importance in the control of plant cell death. In this review article, we summarize and discuss the theoretical and experimental advances that have been made with regard to the roles and mechanisms of eATP in plant cell death. We also make an attempt to address some speculative aspects to help develop and expand future research in this area.