Heparins attenuated histone-mediated cytotoxicity in vitro and improved the survival in a rat model of histone-induced organ dysfunction

Background

The beneficial effects of heparin in the treatment of severe sepsis, septic shock, and sepsis-associated disseminated intravascular coagulation (DIC) have recently been reported. However, the mechanisms underlying the therapeutic benefits of heparin in these conditions have not yet been clearly elucidated. The purpose of this study was to confirm the effect of heparin of neutralizing histone toxicity.

Methods

Rat models of histone H3-induced organ dysfunction were administered in a low or high dose of unfractionated heparin (UFH), low-molecular-weight heparin (LMWH), or argatroban, and the therapeutic effects of each anticoagulant were examined. In another series, the survival of the histone H3-administered animals was evaluated. Furthermore, the effect of each of the aforementioned anticoagulants on cell death induced by histone H3 was examined in cultured vascular endothelial cells and leukocytes.

Results

Although UFH, LMWH, and argatroban significantly suppressed the histone-induced decrease of the WBC and platelet counts in the animal models of organ dysfunction, only UFH and LMWH attenuated hepatic and renal dysfunction. In addition, the mortality was significantly reduced only by high-dose UFH and LMWH. The in vitro study revealed that both vascular endothelial cell death and leukocyte cell death were significantly attenuated by UFH and LMWH but not by argatroban.

Conclusions

The histone-neutralizing effect of heparin may contribute to the beneficial effects of heparins observed in the animal study. The results of the in vitro study further confirmed the above contention and suggested that heparin binds to histones to attenuate the cytotoxic actions of the latter. Since heparin has been demonstrated to protect animals from the organ damage induced by histones and consequently reduce the mortality, administration of heparin could become a treatment of choice for patients suffering from severe sepsis.

[A case of Guillain-Barre syndrome in the oldest]

We herein describe the case of a 90-year-old man. He had been treated for type II diabetes mellitus for over twenty years. One day he noticed weakness in the bilateral upper limbs. The next morning the symptoms extended to the bilateral lower limbs. As a result, he was admitted to Shimane University Hospital. MRI showed mild compression of the cervical spinal cord, but it did not account for his neurological symptoms. Because his quadriplegia progressed, we examined the cerebrospinal fluid with albuminocytologic dissociation. A nerve conduction study showed an axonal neuropathy pattern. We diagnosed Guillain-Barre syndrome and started intravenous immunoglobulin (IVIg) therapy 5 mg/kg on the fifth day after admission. All deep tendon reflexes were absent during the treatment. He was able to get up one week later and could walk by himself two weeks later. Guillain-Barre syndrome is a treatable disease and this disorder should be taken into consideration even if an elderly person presents with quadriplegia.

Synthesis of magnesium ZIF-8 from Mg(BH4)2

Porous Mg(2-methyl imidazolate)₂ (Mg-ZIF-8) was synthesised from Mg(BH₄)₂, and it possesses an uncommon tetrahedral Mg²⁺–N coordination geometry.