Consensus statement from the international consensus meeting on post-traumatic cranioplasty

Background

Due to the lack of high-quality evidence which has hindered the development of evidence-based guidelines, there is a need to provide general guidance on cranioplasty (CP) following traumatic brain injury (TBI), as well as identify areas of ongoing uncertainty via a consensus-based approach.

Methods

The international consensus meeting on post-traumatic CP was held during the International Conference on Recent Advances in Neurotraumatology (ICRAN), in Naples, Italy, in June 2018. This meeting was endorsed by the Neurotrauma Committee of the World Federation of Neurosurgical Societies (WFNS), the NIHR Global Health Research Group on Neurotrauma, and several other neurotrauma organizations. Discussions and voting were organized around 5 pre-specified themes: (1) indications and technique, (2) materials, (3) timing, (4) hydrocephalus, and (5) paediatric CP.

Results

The participants discussed published evidence on each topic and proposed consensus statements, which were subject to ratification using anonymous real-time voting. Statements required an agreement threshold of more than 70% for inclusion in the final recommendations.

Conclusions

This document is the first set of practical consensus-based clinical recommendations on post-traumatic CP, focusing on timing, materials, complications, and surgical procedures. Future research directions are also presented.

Biochemical markers analyzed using microdialysis and traumatic brain injury outcomes

AIM

Traumatic brain injury is a leading cause of disability and mortality among young people. Multiparametric cerebral bedside monitoring is a safe and promising technique for preventing secondary brain damage. The objective of this study was to investigate the usefulness of cerebral microdialysis in predicting the outcomes of patients with traumatic brain injury.

METHODS

Thirty-eight patients (33 males) were included in the study. The GCS on admission was ≤8. The outcome was assessed using the GOS over six months of follow-up.

RESULTS

Among the patients included, 18 had a favorable outcome (GOS=4.5) and the remaining 20 had an unfavorable outcome. L/P ratio and glycerol concentration were statistically significantly higher in the patients with unfavorable prognosis.

CONCLUSION

Biochemical parameters analysed using microdialysis could serve as predictor indexes of clinical outcome several months after the injury.

IL-1RN and IL-1B gene polymorphisms and cerebral hemorrhagic events after traumatic brain injury

OBJECTIVE

To investigate the association of (variable number tandem repeat) interleukin (IL) 1RN and (-511) IL-1B gene polymorphisms with brain hemorrhagic events after traumatic brain injury (TBI).

METHODS

Data from brain CT, Glasgow Coma Scale (GCS) at admission, and 6-month Glasgow Outcome Scale (GOS) and modified Rankin Scale (mRS) were collected for 151 prospectively recruited patients with TBI. IL-1RN and IL-1B genotypes were determined using standard methods. Presence vs absence of any type of brain hemorrhage was the main outcome. Type of brain hemorrhage, GCS at admission, and 6-month GOS and mRS were secondary outcomes. Odd ratios (ORs) and corresponding 95% CI were calculated using logistic regression analyses. In adjusted models, the associations were controlled for age, gender, diffuse brain edema, volume of intracranial hematoma, neurosurgical intervention, and GCS at admission. p values less than 0.01 were considered significant.

RESULTS

Compared with noncarriers, IL-1RN allele 2 carriers had higher odds of having cerebral hemorrhages after TBI (adjusted OR = 4.57; 95% CI = 1.67 to 12.96; p = 0.004). The associations for (-511) IL-1B polymorphism were not significant.

CONCLUSION

There is an association between the presence of interleukin-1RN allele 2 and posttraumatic brain hemorrhage.

A novel function of tissue factor pathway inhibitor-2 (TFPI-2) in human glioma invasion

Human tissue factor pathway inhibitor-2 (TFPI-2) is a Kunitz-type serine protease inhibitor that inhibits plasmin, trypsin, chymotrypsin, cathepsin G, and plasma kallikrein but not urokinase-type plasminogen activator, tissue plasminogen activator, or thrombin. Preliminary findings in our laboratory suggested that the expression of TFPI-2 is downregulated or lost during tumor progression in human gliomas. To investigate the role of TFPI-2 in the invasiveness of brain tumors, we stably transfected the human high-grade glioma cell line SNB19 and the human low-grade glioma cell line Hs683 with a vector capable of expressing a transcript complementary to the full-length TFPI-2 mRNA in either sense (0.7 kb) or antisense (1 kb) orientations. Parental cells and stably transfected cell lines were analysed for TFPI-2 protein by Western blotting and for TFPI-2 mRNA by Northern blotting. The levels of TFPI-2 protein and mRNA were higher in the sense clones (SNB19) and decreased in the antisense (Hs683) clones than in the corresponding parental and vector controls. In spheroid and matrigel invasion assays, the SNB19 parental cells were highly invasive, but the sense-transfected SNB-19 clones were much less invasive; the antisense-transfected Hs683 clones were more invasive than their parental and vector controls. After intracerebral injection in mice, the sense-transfected SNB19 clones were less able to form tumors than were their parental and vector controls, and the antisense-Hs683 clones but not the parental or vector controls formed small tumors. This is the first study to demonstrate that down- or upregulation of TFPI-2 plays a significant role in the invasive behavior of human gliomas.

Elevated levels of cathepsin B in human glioblastoma cell lines

Degradation of the extracellular matrix is a prerequisite for the invasive phenotype in glioma cells. Several proteases released by invading tumor cells seem to participate in the focal degradation of extracellular matrix proteins. Using enzymatic assays, Western blotting, and Northern blotting techniques, we investigated whether cathepsin B level was associated with malignant grade in seven human glioma cell lines. Cathepsin B activity and protein content levels were higher in glioblastoma cell lines than in anaplastic astrocytoma or low-grade glioma cell lines. Cathepsin B transcripts were overexpressed in glioblastoma cell lines relative to their expression in anaplastic astrocytoma and low-grade glioma cell lines. Cathepsin B promoter activity and amount of SP-1 complexes were much higher in glioblastoma cell lines than in anaplastic astrocytoma or low-grade glioma cell lines. Finally, E-64, an inhibitor of cathepsin B, inhibited both cathepsin B enzymatic activity and the invasiveness of glioblastoma cell lines. These results strongly support a role for cathepsin B in glioblastoma cell lines and suggest that inhibition of cathepsin B activity may be proven useful in cancer therapy.

A novel role of tissue factor pathway inhibitor-2 in apoptosis of malignant human gliomas

Tissue factor pathway inhibitor-2 (TFPI-2) is a 32 kDa serine protease inhibitor found at high levels in extracellular matrix. Recombinant human TFPI-2 has recently been shown to be a strong inhibitor of trypsin, plasmin, plasma kallikrein, and factor XIa amidolytic activity. Earlier studies in our laboratory showed that the expression of TFPI-2 is lost during tumor progression in human gliomas. We stably transfected this protease inhibitor in multiform glioblastoma cell line (SNB-19) and in low-grade glioma cell line (Hs683) in sense and antisense orientation respectively. This confirmed that the upregulation/down-regulation of TFPI-2 plays a significant role in the invasive behavior of human gliomas both in vitro and in vivo models. Collectively, these results suggested an idea to determine whether TFPI-2 is necessary for cell survival and inhibition of tumor formation in nude mice, due to apoptosis of intracerebrally injected SNB-19 cells. In the present study we determined p-ERK levels and found that they are decreased in TFPI-2 over-expressed clones (SNB-19) and increased in TFPI-2 down-regulated clones (Hs683). We also checked the levels of BAX/BCl-2, caspases (for e.g., 9, 7, 3, 8), PARP, cytochrome-c and Apaf-1. Moreover, the increase of apoptosis in vitro is associated with increased and decreased expression of apoptotic protein BAX in sense clones (SNB-19) and antisense clones (Hs683) respectively, when compared to controls and vice versa with Bcl-2 the anti-apoptotic protein. Caspases (9, 7 and 3), cytochrome-c, Apaf-1 and PARP levels are increased in SNB-19 and decreased in Hs683. Caspase 8 was not expressed in either cell line. Caspases 9 and 3 activity assay revealed higher activity in sense clones (SNB-19) but lesser in antisense clones (Hs683) compared to controls. This is the first report of TFPI-2 playing a novel role in cell survival in human gliomas.

Role of tissue factor pathway inhibitor-2 (TFPI-2) in amelanotic melanoma (C-32) invasion

Human tissue factor pathway inhibitor-2 (TFPI-2), also known as placental protein (PP5) and matrix-associated serine protease inhibitor (MSPI), is a 32-kDa extracellular matrix (ECM) protein consisting of three tandomly arranged Kunitz-type domains that inhibits plasmin, trypsin, chymotrypsin, cathepsin G and plasma kallikrein but not urokinase and tissue-type plasminogen activators or thrombin. Earlier studies in our laboratory revealed that the production of TFPI-2 is reduced or absent during the tumor progression of human gliomas. In the present study, we investigated the role of TFPI-2 in the invasiveness of the amelanotic melanoma cell line C-32. We stably transfected C-32 cells with a vector capable of expressing TFPI-2 in a sense orientation (0.7 kb). TFPI-2 protein production was then determined by western blotting and the mRNA level by northern blotting in parental and stably transfected (vector and sense) clones. The levels of TFPI-2 protein and mRNA were significantly higher in the sense clones, but neither was detected in parental and vector control clones. In addition, in vitro Matrigel invasion/migration assays revealed that the invasive behavior of sense clones was inhibited compared with the behavior of parental and vector clones. This is the first study to show that the upregulation of TFPI-2 plays a significant role in reducing the invasive behavior of human amelanotic melanomas.

Overexpression of tissue factor pathway inhibitor-2 (TFPI-2), decreases the invasiveness of prostate cancer cells in vitro

Human tissue factor pathway inhibitor-2 (TFPI-2) is a 32-kDa serine protease inhibitor that inhibits plasmin, trypsin, chymotrypsin, cathepsin G, and plasma kallikrein but not urokinase and tissue-type plasminogen activators or thrombin. After discovering that TFPI-2 expression is down-regulated or lost during tumor progression, we investigated the role of TFPI-2 in the invasiveness of the prostate cancer cell line (LNCaP). We stably transfected LNCaP cells with a 0.7-kb vector expressing TFPI-2 in the sense orientation and measured the expression of TFPI-2 protein and mRNA by these cells by western and northern blotting. Neither TFPI-2 protein nor mRNA was expressed by parental LNCaP cells or vector-transfected controls, but levels of both protein and mRNA were significantly increased in the sense-TFPI-2 clones. The sense clones were less invasive than the control cells in Matrigel invasion and spheroid migration assays. This is the first demonstration that upregulation of TFPI-2 plays a significant role in the invasive behavior of human prostate cancer cells.