Bio-modulators in platelet-rich plasma: a comparison of the amounts in products from healthy donors and patients produced with three different techniques.

BACKGROUND: Platelet-rich plasma consists of platelets concentrated in a small volume of plasma and constitutes a reservoir of bio-modulators potentially useful in tissue repair. The amounts of bio-modulators detectable in platelet-rich plasma prepared with various commercial or "in house" methods have been reported, but virtually all the analyses described have been performed on platelet-rich plasma derived from healthy donors. Since leucocyte contamination is technically unavoidable, we investigated whether platelet-rich plasma prepared from patients could contain different amounts of bio-modulators because of a possible activated status of the leucocytes. MATERIALS AND METHODS: We evaluated platelet-rich plasma prepared with three different techniques (the commercial Vivostat and Biomet recover GPS II systems and an "in house" method) starting from whole blood from healthy donors and patients. Specifically, we compared the levels of sHLA-I, sFasL, platelet-derived growth factor, transforming growth factors-beta and vascular endothelial growth factor in the platelet-rich plasma releasates according to the method of preparation and to the immune system activation status of the subjects. RESULTS: With the exception of sHLA-I levels, no differences were found in the surrogate indices of lymphocyte activation between healthy donors and patients. No significant differences were found in sHLA-I, sFasL, platelet-derived growth factor, transforming growth factors-beta and vascular endothelial growth factor levels detectable in platelet-rich plasma produced with the three different methods in either healthy donors or patients. DISCUSSION: On the whole our findings indicate that the overall content of bio-modulators in autologous platelet-rich plasma is not influenced by T-lymphocyte activation status, at least in patients with uncomplicated femoral fractures. The amounts of sFasL and sHLA-I detected in all the platelet-rich plasma releasates studied were very small, far below the amounts detectable in all clinically available blood derivatives and absolutely insufficient to induce sHLA-I and/or sFasL mediated immunomodulation.

Protective effects of Batroxobin on spinal cord injury in rats.

Expansion of the secondary injury following primary spinal cord injury is a major pathological event that increases destruction in the spinal cord, so measures to reduce secondary injury are needed. Our previous study demonstrated that, at the front of the expanding secondary injury in the spinal cord, there is an ischemic area in which many neurons can still be rescued. Therefore, enhancement of blood circulation in the cord may be helpful, and indeed, we found that a traditional Chinese medicine, shu-xue-tong, efficiently reduces the secondary injury. The aim of the present study was to investigate the effect of reducing fibrinogen with Batroxobin, a drug widely used clinically for ischemia, in rats with spinal cord contusion. We found that both 2 and 4 Batroxobin units (BU)/kg efficiently decreased the plasma fibrinogen, and 2 BU/kg significantly increased spinal blood flow, enhanced neuronal survival, mitigated astrocyte and microglia activation, and improved locomotor recovery. However, 4 BU/kg had no effect on the secondary spinal cord injury. These data suggest that Batroxobin has multiple beneficial effects on spinal cord injury, indicating a potential clinical application.

GAP-43 expression and pathological changes of temporal infarction in rats and effects of batroxobin.

UNLABELLED: To study the changes of the expression of growth-associated protein-43 (GAP-43) and pathology in temporal infarction of rats photochemically induced and the effects of batroxobin. METHODS: Immunohistochemical technique and hematoxylin-eosin stain was used to show the changes of the expression of GAP-43 and pathology. RESULTS: In infarction group, GAP-43 expression was markedly increased on the infarction and surrounding tissues at 24 h cerebral infarction. The expression reached peak level at 72 h after cerebral infarction and was decreased at 7 d after cerebral infarction. However, in batroxobin-treated group, GAP-43 expression was increased and the pathological changes were much slight as compared with infarction group. CONCLUSION: The expression of GAP-43 increases in infarction of temporal neocortex and batroxobin promotes the expression of GAP-43 and ameliorates the pathological changes in infarction of temporal neocortex.

Effect of batroxobin on neuronal apoptosis during focal cerebral ischemia and reperfusion in rats.

We have found that Batroxobin plays a protective role in ischemic brain injury, which attracted us to investigate the effect of Batroxobin on apoptosis of neurons during cerebral ischemia and reperfusion. The apoptotic cells in ischemic rat brains at different reperfusion intervals were tested with method of TdT-mediated dUTP-DIG nick end labeling (TUNEL) and the effect of Batroxobin on the apoptosis of neurons was studied in left middle cerebral artery (LMCA) occlusion and reperfusion in rat models (n = 18). The results showed that few scattered apoptosis cells were observed in right cerebral hemispheres after LMCA occlusion and reperfusion, and that a lot of apoptosis cells were found in left ischemic cortex and caudoputamen at 12 h reperfusion, and they reached peak at 24 h-48 h reperfusion. However, in the rats pretreated with Batroxobin, the number of apoptosis cells in left cerebral cortex and caudoputamen reduced significantly and the neuronal damage was much milder at 24 h reperfusion than that of saline-treated rats. The results indicate that administration of Batroxobin may reduce the apoptosis of neurons induced by cerebral ischemia and reperfusion and afford significant cerebroprotection in the model of focal cerebral ischemia and reperfusion.

Metabolic changes in rats with photochemically induced cerebral infarction and the effects of batroxobin: a study by magnetic resonance imaging, 1H- and 31P-magnetic resonance spectroscopy.

Metabolic changes in rats with photochemically induced cerebral infarction and the effects of batroxobin were investigated 1, 3, 5 and 7 days after infarction by means of magnetic resonance imaging (MRI), 1H- and 31P-magnetic resonance spectroscopy (MRS). A region of T2 hyperintensity was observed in left temporal neocortex in infarction group and batroxobin group 1, 3, 5 and 7 days after infarction. The volume of the region gradually decreased from 1 day to 7 days after infarction. The ratio of NAA/Cho + Cr in the region of T2 hyperintensity in the infarction group was significantly lower than that in the corresponding region in the sham-operated group 3, 5 and 7 days after infarction respectively (P < 0.05). Lac appeared in the region of T2 hyperintensity in the infarction group 1, 3, 5 and 7 days after infarction, but it was not observed in the corresponding region in sham-operated group at all time points. Compared with the sham-operated group, the ratios of beta ATP/PME + PDE and PCr/PME + PDE of the whole brain in the infarction group were significantly lower 1, 3 and 5 days after infarction respectively (P < 0.05), and the ratio of beta ATP/PCr also was significantly lower 1 day after infarction (P < 0.05). Batroxobin significantly decreased the volume of the region of T2 hyperintensity 1 and 3 days after infarction (P < 0.05), significantly increased the ratio of NAA/Cho + Cr in the region 5 and 7 days after infarction (P < 0.05), significantly decreased the ratios of Lac/Cho + Cr and Lac/NAA in the region 5 and 7 days after infarction (P < 0.05), and significantly increased the ratios of beta ATP/PME + PDE and beta ATP/PCr in the whole brain 1 day after infarction (P < 0.05). The results indicated that the infracted region had severe edema, increased Lac and apparent neuronal dysfunction and death, and energy metabolism of the whole brain decreased after focal infarction, and that batroxobin effectively ameliorated the above-mentioned abnormal changes.

Effect of batroxobin on expression of neural cell adhesion molecule in temporal infarction rats and spatial learning and memory disorder.

The effect of Batroxobin expression of neural cell adhesion molecule (NCAM) in left temporal ischemic rats with spatial memory disorder was investigated by means of Morri's water maze and immunohistochemical methods. The results showed that the mean reaction time and distance of temporal ischemic rats for searching a goal were significantly longer than those of sham-operated rats and at the same time NCAM expression of left temporal ischemic region was significantly increased. However, the mean reaction time and distance of Batroxobin-treated rats were shorter and they used normal strategies more often and earlier than those of ischemic rats. The number of NCAM immune reactive cells of Batroxobin-treated rats was more than that of ischemic group. In conclusion, Batroxobin can improve spatial memory disorder of temporal ischemic rats and the regulation of the expression of NCAM is probably related to the neuroprotective mechanism.

Batroxobin against anoxic damage of rat hippocampal neurons in culture: morphological changes and Hsp70 expression.

Batroxobin, the thrombin-like enzyme, is used for therapeutic defibrination. We have found that batroxobin has good therapeutic effect in ischemic reperfusion rats and clinical practices in vivo. But we have not studied the neuroprotective effect of batroxobin on anoxic hippocampal neurons in vitro. The purpose of this study was to obtain further information on the mechanism of the batroxobin-induced neuroprotection and examine the neuroprotective effect on neurons exposed to anoxia. The effect of batroxobin on anoxic damages in cultured hippocampal neurons of neonatal rats was investigated by using morphological changes and heat shock protein 70 Kd (Hsp70) immunoreactive expression as indicators. The results indicate that batroxobin, besides its defibrination, may have a direct neuroprotective effect on anoxic damage of hippocampal neurons.

Effect of batroxobin on expression of c-Jun in left temporal ischemic rats with spatial learning and memory disorder.

The effect of Batroxobin on expression of c-Jun in left temporal ischemic rats with spatial memory disorder was investigated by means of Morri's water maze and immunohistochemistry methods. The results showed that the mean reaction time and distance of temporal ischemic rats for searching a goal were significantly longer than those of sham-operated rats, and at the same time c-Jun expression of left temporal ischemic region was significantly increased. However, the mean reaction time and distance of Batroxobin-treated rats were shorter and they used normal strategies more often and earlier than those of ischemic rats. The number of c-Jun immune reactive cells of Batroxobin-treated rats was also less than that of ischemic group. In conclusion, Batroxobin can improve spatial memory disorder in temporal ischemic rats, and the down-regulation of the expression of c-Jun is probably related to the neuroprotective mechanism.

Local delivery of antithrombotic drug prevents restenosis after balloon angioplasty in atherosclerotic rabbit artery.

We investigated the ability of various antithrombotic drugs, delivered locally, to prevent restenosis after angioplasty in hypercholesterolemic rabbits. After dilating atherosclerotic iliac stenoses by balloon angioplasty, a low dose of heparin or a new antithrombotic drug, such as low molecular weight heparin (fragmin), argatroban, or batroxobin, was delivered locally using the balloon double-occlusion technique. In 1 group, high-dose heparin was administered intravenously. Animals that received no drugs served as a control group. After angioplasty, the stenotic segment was dilated and the mean percentage luminal stenosis fell from 89% to 9% in the group that received locally delivered heparin, from 88% to 7% in the group that received locally delivered argatroban, from 87% to 11% in the group that received locally delivered fragmin, from 88% to 15% in the group that received locally delivered batroxobin, from 82% to 18% in the group that received i.v. heparin (p < 0.0001 compared with before angioplasty in each case), and from 84% to 17% in the control group (p < 0.005 compared with before angioplasty). Twenty-eight days after angioplasty, the percentage luminal stenosis remained at 14% in the group that received locally delivered argatroban, 15% in the group that received locally delivered fragmin, and 28% in the group that received locally delivered batroxobin, whereas it increased to 45% in the group that received i.v. heparin, 30% in the group that received locally delivered heparin and 72% in the control group (p < 0.05 compared with after angioplasty in each case). Thus, local delivery low doses of new antithrombotic drugs prevents restenosis after angioplasty without affecting systemic coagulability; heparin, whether administered locally or intravenously, was less effective than the new drugs in preventing restenosis.