Development of a novel emergency hemostatic kit for severe hemorrhage.

Photocrosslinkable chitosan (Az-CH-LA) contains lactose moieties and photoreactive azide groups, and its viscous solution forms an insoluble hydrogel on exposure to UV irradiation. We previously developed an emergency hemostatic kit using the Az-CH-LA solution, calcium alginate, and a UV irradiation apparatus. However, a suitable UV irradiation apparatus is required to effectively convert the Az-CH-LA solution into a hydrogel, and power supply to use the UV irradiation apparatus may not always be available in a disaster area or battlefield. To address this problem, we produced a portable, battery-powered UV irradiation apparatus constituting a novel hemostatic kit for severe hemorrhage. When the hemostatic kit using the UV irradiation apparatus was examined using a rat model of severe hemorrhage, the survival rate increased up to 73%. Hematological values as markers of hemorrhage did not change significantly over the first 3 days. In this study, we describe the characteristics of a portable UV irradiation apparatus and its use in an emergency hemostatic kit prepared using Az-CH-LA and calcium alginate for severe hemorrhage.

Liposome-encapsulated hemoglobin attenuates cardiac dysfunction and sympathetic activity during hypohemoglobinemic shock.

The use of liposome-encapsulated hemoglobin (LHb), which is a cellular Hb, has been demonstrated to be beneficial in the treatment of hypohemoglobinemic shock. As a molecule of appropriate size (220 nm) that can carry oxygen, LHb may ameliorate cardiac dysfunction during lethal hemodilation. The purpose of this study was to determine the efficacy of LHb transfusion in relieving cardiovascular dysfunction in a rat model of lethal progressive hemodilution. Over the course of 150 min, rats were subjected to blood withdrawal (0.2 mL/min) and simultaneously transfused with LHb, washed rat red blood cells, or 5% albumin. Temporal changes in cardiac function, heart-type fatty acid-binding protein levels, plasma levels of catecholamines, heart rate variability, and hypoxia-inducible factor 1α expression were measured during lethal progressive hemodilution. More than 80% of the rats transfused with either LHb or washed rat red blood cells survived for 8 days. Liposome-encapsulated hemoglobin transfusion suppressed hypoxia-inducible factor 1α expression in the heart, maintained low levels of heart-type fatty acid-binding protein, and attenuated sympathetic nerve activity as reflected by changes in heart rate variability and plasma levels of epinephrine and norepinephrine. The results indicate that LHb attenuates cardiac dysfunction and sympathetic overactivity during lethal hemorrhage.

Intraosseous transfusion with liposome-encapsulated hemoglobin improves mouse survival after hypohemoglobinemic shock without scavenging nitric oxide.

Recently, we developed liposome-encapsulated hemoglobin (LEH), a novel cellular hemoglobin-based oxygen carrier. We hypothesized that the LEH effectively suppresses scavenging of nitrogen oxides by sequestering hemoglobin, thereby being useful for resuscitation from hemorrhagic shock, especially in prehospital settings where blood transfusion is not available. However, putting a catheter into the peripheral vessels is sometimes difficult in prehospital resuscitation, because these vessels collapse in patients with hemorrhagic shock. The intraosseous route does not collapse under such conditions. We here studied the resuscitation of severe hypohemoglobinemia following massive hemorrhage using intraosseous (intrafemur) transfusion with LEH in mice. First, we examined the effect of intravenous transfusion with LEH on the resuscitation of mice with fatal hypohemoglobinemia that was made with progressive hemodilution by blood exchanges. Despite a success in initial resuscitation without scavenging of NO2 or NO3, LEH transfusion did not significantly improve mouse survival 72 h later as compared with red blood cell (RBC) transfusion. In other experiments, hypohemoglobinemic mice were also made with blood withdrawal and intraosseous infusion with 5% albumin. Thereafter, the mice were rescued with intraosseous transfusion of LEH or RBCs. Unlike intravenous transfusion, intraosseous transfusion with LEH (but not such transfusion with RBCs) significantly increased mouse survival without scavenging of NO2 or NO3, presumably because LEH vesicles were much smaller than RBCs, thereby effectively flowing into the circulation from the femur. Thus, intraosseous transfusion with LEH may be a candidate strategy for efficient prehospital resuscitation from hemorrhagic shock.

Efficacy of peritoneal oxygenation using a novel artificial oxygen carrier (TRM-645) in a rat respiratory insufficiency model.

PURPOSE: Supplemental oxygenation is essentially important in critically ill patients with potentially reversible pulmonary insufficiency. An extracorporeal membrane oxygenator and percutaneous cardiopulmonary support have been used for these patients. However, these techniques are associated with so many complications that an additional new therapeutic modality is required. The purpose is to investigate if the peritoneal cavity can be used as "extrapulmonary respiration" that is analogous to peritoneal dialysis and utilizes the efficacy of liposome-encapsulated hemoglobin (artificial oxygen carrier; TRM-645). METHODS: Rats weighing an average of 300 g (n = 18) received an incision in the right chest to generate pneumothorax, which resulted in severe and lethal hypoxia. Oxygenated TRM-645 and human red blood cells (MAP group) were administered into the peritoneum in the experimental rats' pneumothorax model. No treatment except the right pneumothorax was administered to the sham group. RESULTS: Survival times from the pneumothorax were significantly longer in the TRM-645 and MAP groups than in the sham group (32.0 +/- 6.9 and 22.0 +/- 4.9 min vs 9.2 +/- 1.9 min, P < 0.01). In addition, an arterial blood gas analysis showed that the oxygenation in levels significantly improved. CONCLUSIONS: The abdomen (peritoneum) can potentially become an "artificial lung" that can be employed in critical care settings. TRM-645 provides an alternative to the use of washed human red blood cells.

Effect of photocrosslinkable chitosan hydrogel and its sponges to stop bleeding in a rat liver injury model.

This study examined the hemostatic efficacy of photocrosslinkable chitosan hydrogel-mixed photocrosslinked chitosan sponges (PCM-S) after hepatic injury in rats. The left lobe of the liver was penetrated with a dermal punch to produce a penetrating wound in heparinized and nonheparinized rats. Treated rats either had PCM-S applied into the wound and then were immediately ultraviolet irradiated, or they had TachoComb (TC) inserted into the wound. Blood loss, hemostasis, and survival were quantified after the hepatic injury. Measurements on serum alanine aminotransferase in nonheparinized rats and hemoglobin concentrations and histologic examinations in heparinized rats were performed to assess hepatic function. Although the hemostatic effect in the PCM-S-treated nonheparinized rats was identical to that of the TC-treated group, PCM-S-treatment has higher hemostatic effect in heparinized rats. No adverse events related to the use of PCM-S were detected in blood and histologic examinations.

Cardiac dysfunction induced by experimental myocardial infarction impairs the host defense response to bacterial infection in mice because of reduced phagocytosis of Kupffer cells.

OBJECTIVE: This study was undertaken to investigate the effects of cardiac dysfunction induced by experimental myocardial infarction on the host defense response to bacterial infection and the role of Kupffer cells in mediating this response. METHODS: Myocardial infarction was induced in C57BL/6 mice by ligation of the left anterior descending coronary artery. Mice were challenged with Escherichia coli intravenously 1, 5, and 14 days after myocardial infarction or sham operation. Thereafter, the cytokine production and the function of their Kupffer cells were assessed. RESULTS: Mice with myocardial infarction showed remarkable cardiac dysfunction and had a significantly lower survival than sham mice after bacterial challenge at 5 days after surgery; bacterial challenge at 1 or 14 days after surgery resulted in no difference in survival between myocardial infarction and sham mice. The phagocytic activity of Kupffer cells, assessed by fluorescein isothiocyanate microspheres, remarkably decreased in mice with myocardial infarction 5 days after surgery. Serum peaks of tumor necrosis factor and interferon-gamma after bacterial challenge were also suppressed in mice with myocardial infarction at 5 days. Production of these cytokines and immunoglobulin-M from liver mononuclear cells was also impaired in mice with myocardial infarction. Enhancement of the phagocytic activity of Kupffer cells by C-reactive protein significantly improved survival after infection in mice with myocardial infarction, although neither interleukin-18 nor immunoglobulin-M treatment improved survival. CONCLUSIONS: Cardiac dysfunction induced by myocardial infarction renders mice susceptible to bacterial infection and increases mortality because of a reduced ability of Kupffer cells to clear infectious bacteria. C-reactive protein-enhanced phagocytic activity of Kupffer cells may improve the poor prognosis after bacterial infection in mice with myocardial infarction.

Liposome-encapsulated hemoglobin transfusion rescues rats undergoing progressive hemodilution from lethal organ hypoxia without scavenging nitric oxide.

OBJECTIVE: To investigate the efficacy of liposome-encapsulated hemoglobin (LHb) transfusion in rats undergoing lethal progressive hemodilution. SUMMARY BACKGROUND DATA: Unlike other acellular hemoglobin-based oxygen carriers, LHb has lipid bilayer membranes that are similar to mammalian red blood cells (RBCs), which prevent hemoglobin from having any direct contact with the blood components and the endothelium. Acellular hemoglobin has a high affinity for nitric oxide (NO), and because they are reported to behave as NO scavengers, acellular hemoglobin-based oxygen carriers could have pressor effects on the peripheral vessels. During a massive hemorrhage, acellular hemoglobin caused vasoconstriction could decrease peripheral perfusion, thereby leading to diminished oxygen delivery. METHODS: Rats were subjected to blood withdrawal (0.2 mL/min) with a simultaneous resuscitation using an isovolemic fluid transfusion that contained LHb, 5% albumin, or washed rat RBCs for 150 minutes (n = 15 in each group). RESULTS: All rats transfused with LHb or RBCs were rescued from lethal progressive hemodilution, whereas none of the albumin-transfused rats survived. LHb did not affect the plasma NO metabolite levels, suggesting it was not a potent NO scavenger. LHb also improved hemodilution-induced metabolic acidosis, and reduced exaggerated neuroendocrine responses and injuries to the heart, liver, and kidney. It suppressed expression of hypoxia-inducible factor-1alpha in the liver and kidney, suggesting improvement of hypoxia at molecular response levels. However, neither transfused LHb nor RBCs improved the acute lung injury that occurs after progressive hemodilution. CONCLUSION: LHb transfusion is effective in rescuing rats undergoing progressive hemodilution from lethal organ hypoxia without scavenging NO.

Pyogenic vertebral osteomyelitis after surgery for rupture of the aortic arch.

Vertebral osteomyelitis is a very rare and intractable complication after vascular surgery. We describe a case of pyogenic vertebral osteomyelitis induced by methicillin-resistant Staphylococcus Aureus sepsis following surgery for traumatic rupture of the aortic arch, successfully managed with long-term antibiotic therapy for 75 weeks.

Expansion and characterization of adipose tissue-derived stromal cells cultured with low serum medium.

Adipose tissue contains a population of cells that have extensive self-renewal capacity and the ability to differentiate along multiple lineages. In addition, adipose tissue-derived stromal cells (ATSCs) are able to differentiate into various cell types that may be useful for autologous cell transplantation for defects of bone, cartilage, adipose, and tendon, etc. Most protocols for in vitro cultures of ATSCs include fetal bovine serum (FBS) as a nutritional supplement. However, in some cell cultures, it involves multiple doses of FBS, which raises a concern over possible infections as well as immunological reactions that are caused by medium-derived FBS proteins, sialic acid, etc. In this study, we were able to expand mouse ATSCs using low mouse serum media containing collagen type I, heparin-carrying polystyrene, and fibroblast growth factor (FGF)-2. These expanded mouse ATSCs maintained their multilineage potential for differentiation into adipocytes, osteoblasts, and chondrocytes. Therefore, this method, which uses autologous cells and low serum media, may be able to be utilized for clinical cell therapies.

The peritoneum as a novel oxygenation organ: revitalization of intraperitoneal oxygenation.

Supplemental oxygenation is important in reversible pulmonary failure. To determine whether the peritoneal cavity can be used as a source of "extrapulmonary respiration," we perfused the peritoneal cavity with oxygenated red blood cells (RBCs) and saline, and measured the amount of oxygenation delivered through the peritoneum of dogs under controlled ventilation. Inflow and outflow catheters were placed in the peritoneal cavity and connected to a perfusion circuit. We investigated the safety of this procedure by examining the relationship between intraperitoneal infusion volume and hemodynamic changes in dogs that underwent peritoneal perfusion with oxygenated RBC (n = 6) and with oxygenated saline (n = 6). The controls comprised dogs that underwent a sham operation (n = 6). We found that an intraperitoneal infusion of less than 1,250 mL was hemodynamically safe. Oxygenation levels (PaO2) increased most obviously with an intraperitoneal infusion of oxygenated RBC. The peritoneum can potentially serve as an "artificial lung" in critically ill patients.