The comparative effects of recombinant human erythropoietin and darbepoetin-alpha on cerebral vasospasm following experimental subarachnoid hemorrhage in the rabbit

Does erythropoietin affect the outcome and complication rates of patient with traumatic brain injury? A pooled-analysis

OBJECTIVE

The aim of this meta-analysis was to review the scientific literature published until April 18, 2021, to summarize existing knowledge on the efficacy and safety of erythropoietin (EPO) for traumatic brain injury (TBI).

METHODS

This systematic review followed PRISMA guidelines. Randomized controlled trials (RCTs) reporting on the efficacy and safety of EPO in the treatment of TBI were systematically searched in relevant electronic databases according to a pre-designed search strategy. The primary outcomes are the mortality; and secondary outcomes are the good functional outcome (GFO) and adverse events (AEs).

RESULTS

A total of 10 RCTs involving 2,402 participants fulfilled the inclusion criteria. The results showed that there is a significant difference in terms of the mortality (RR = 0.67, 95% CI = 0.54-0.84, P = 0.0003) and seizure rate (RR = 0.52, 95% CI = 0.29-0.96, P = 0.04) between the EPO groups compared to those in the control groups. However, compared with the control groups, the GFO in the EPO groups was not statistically significant (RR = 1.18, 95% CI = 0.93-1.48, P = 0.17).

CONCLUSIONS

Findings of the present meta-analysis suggest that the use of EPO could reduce mortality rate in patients with TBI, without increasing the incidence of AEs. EPO has potential research and application value in the treatment of TBI.

Amelioration of Cerebral Vasospasm and Secondary Injury by Vigabatrin After Experimental Subarachnoid Hemorrhage in the Rabbit

BACKGROUND

Vigabatrin, an antiepileptic drug, increases the level of gamma aminobutyric acid in the brain by inhibiting its catabolism. Because gamma aminobutyric acid has been proved to have vasodilatory effects, in the present study, we investigated the effect of vigabatrin to treat experimental subarachnoid hemorrhage (SAH)-induced vasospasm.

METHODS

A total of 30 New Zealand white rabbits were divided into 3 groups of 10 each: the control group, SAH group, and vigabatrin group. Experimental SAH was established by injection of autologous arterial blood into the cisterna magna. In the vigabatrin group, the rabbits were administered vigabatrin for 3 days after induction of the SAH. The first dose of vigabatrin was given 2 hours after SAH induction. A daily dose of 500 mg/kg vigabatrin was administered intraperitoneally. After 3 days, the rabbits were sacrificed, and the brains were removed, together with the cerebellum and brainstem. The basilar artery wall thickness and lumen areas were measured. The neuronal degeneration in the hippocampus (CA1, CA3, and dentate gyrus) was also evaluated.

RESULTS

The arterial wall thickness of the vigabatrin group was less than that in the SAH group (P < 0.001), and the mean luminal area of the vigabatrin group was greater than that in the SAH group (P < 0.001). Additionally, the hippocampal neuronal degeneration score of the vigabatrin group was lower than that of the SAH group (P < 0.001).

CONCLUSION

These findings have indicated that vigabatrin has a vasodilatory effect in an experimental SAH model in the rabbit. Moreover, it showed a neuroprotective effect in the hippocampal neurons against secondary injury induced by SAH.

The effects of Cinnamaldehyde on early brain injury and cerebral vasospasm following experimental subarachnoid hemorrhage in rabbits

The neuroprotective and vasodilatory effects of cinnamaldehyde have been widely studied and documented. On the basis of these findings, we hypothesized that cinnamaldehyde exhibits therapeutic effects on subarachnoid hemorrhage-induced early brain injury and cerebral vasospasm. Thirty-two adult male New Zealand white rabbits were randomly divided into four groups of eight rabbits: control, subarachnoid hemorrhage, subarachnoid hemorrhage + vehicle, and subarachnoid hemorrhage + cinnamaldehyde. An intraperitoneal dose of 50 mg/kg cinnamaldehyde was administered 5 min following an intracisternal blood injection, followed by three further daily injections at identical doses. The animals were sacrificed 72 h after subarachnoid hemorrhage was induced. The cross-sectional areas and arterial wall thicknesses of the basilar artery were measured and hippocampal degeneration scores were evaluated. Treatment with cinnamaldehyde was effective in providing neuroprotection and attenuating cerebral vasospasm after subarachnoid hemorrhage in rabbits. It effectively increased the cross-sectional areas of the basilar artery and reduced the arterial wall thickness; in addition, hippocampal degeneration scores were lower in the cinnamaldehyde group. The findings of this study showed, for the first time to our knowledge, that cinnamaldehyde exhibits neuroprotective activity against subarachnoid hemorrhage-induced early brain injury and that it can prevent vasospasm. Potential mechanisms underlying the neuroprotection and vasodilation were discussed. Cinnamaldehyde could play a role in subarachnoid hemorrhage treatment.

Effects of 2-Aminoethyl Diphenylborinate, a Modulator of Transient Receptor Potential and Orai Channels in Subarachnoid Hemorrhage: An Experimental Study

BACKGROUND

Cerebral vasospasm remains a serious problem affecting morbidity and mortality in patients with subarachnoid hemorrhage (SAH) during neurosurgery. We aimed to demonstrate the role of the transient receptor potential channel and other channels for Ca²⁺ in the etiology of cerebral vasospasm using 2-aminoethyl diphenylborinate (2-APB) and the effective dose range of an unstudied pharmacological agent, which can limit vasospasm.

METHODS

We performed an experimental study using 32 Sprague-Dawley rats divided into 4 groups: sham group (n = 8), SAH group (n = 8), 2-APB group (SAH rats intraperitoneally administered with 0.5 mg/kg 2-APB; n = 8), and 2-APB-2 group (SAH rats intraperitoneally administered with 2 mg/kg 2-APB; n = 8). The rats were sacrificed after 24 hours, and superoxide dismutase, glutathione peroxidase, malondialdehyde, tumor necrosis factor-α, and interleukin-1β in the brain tissue and serum were measured. The histopathological investigation of brain tissue included measurement of the luminal diameter and wall thickness of the basilar artery (BA), and apoptotic cells in the hippocampus were counted after caspase staining.

RESULTS

Autologous arterial blood injection into the cisterna magna caused vasospasm in rats. 2-APB treatment increased the BA wall thickness and reduced the BA lumen diameter, inducing significant vascular changes. 2-APB also alleviated cell apoptosis at 24 hours after SAH.

CONCLUSION

In experimental SAH in rats, 2-APB treatment increased the BA wall thickness and reduced the BA lumen diameter, inducing significant vascular changes. 2-APB also alleviated cell apoptosis at 24 hours after SAH.

Correction of ischemic optic neuropathy in rats by carbamylated darbepoetin

Introduction: The protective effects of carbamylated darbepoetin on the model of ischemic optic neuropathy in rats were revealed.

Objectives: To increase the effectiveness of pharmacological correction of experimental ischemic optic neuropathy in an experiment by using carbamylated darbepoetin.

Methods: Measuring the microcirculation level in the retina of rats was carried out using laser Doppler flowmetry (LDF). Registration was done by the data acquisition system Biopac-systems MP-150 and AcqKnowledge 4.2 programme.

For microscopy and morphometry, the prepared microslides were scanned using Mirax Desk, a computerised archiving and image analysis system. Image analysis and morphometry were carried out by Pannoramic Viewer 1.15.4.

Results and discussion: In the group with correction of ischemic optic neuropathy by carbamylated darbepoetin, 300 μg/kg, the microcirculation level increases by 41.9%, p&lt;0.05 in comparison with the control group, but also below the norm values by 20.3%, p&lt;0.05. In the group with correction by recombinant erythropoietin, 50 IU/kg, the microcirculation rate increases by 36.7%, p&lt;0.05 in comparison with the control group and significantly lower - by 23.3%, p&lt;0.05 - in comparison with the group of intact animals. Qualitative and quantitative morphological indices (thickness of retinal layers) helped to reveal a neuroprotective effect of carbamylated darbepoetin to a greater extent than that of recombinant erythropoietin.

Conclusion: The obtained data allow drawing a conclusion about partial restoration of blood flow and preservation of neuronal retinal structures when correcting ischemic optic neuropathy in rats with carbamylated darbepoetin to a greater extent than with recombinant erythropoietin.

Pregnancy outcomes after maternal use of thiocolchicoside: A case series

OBJECTIVE

The 2014 report by European Medicines Agency (EMA) restricted the use of thiocolchicoside for all reproductive-age women. In this study, we aim to expand the systematically-collected human data and discuss it within the frame provided by this report.

METHODS

We identified and evaluated the outcomes of 48 prospectively recorded pregnancies referred to Terafar (Teratology Information Service, Izmir, Turkey).

RESULTS

Of 42 pregnancies with first-trimester exposure and known outcomes, 31 resulted in live births, four in miscarriage and seven ended with elective terminations. There were 26 normal outcomes, two major and three minor congenital malformations among the live births.

CONCLUSIONS

Despite a number of limitations, our results and previous case series collectively strengthen the view that thiocolchicoside is unlikely to be a major teratogen. EMA's 2014 report should be revised to reflect this finding, while current restrictions on use should continue until more detailed safety information is available.

An experimental rabbit model of symptomatic cerebral vasospasm with in vivo neuroimaging assessment and ex vivo histological validation

Cerebral vasospasm (CVS) is a severe complication that occurs following aneurysmal subarachnoid hemorrhage (SAH). Magnetic resonance angiography (MRA) has been used to evaluate brain injury following SAH in humans. The present study was designed to assess a rabbit model of symptomatic CVS (SCVS) and the utility of MRA in evaluating SCVS in rabbits. Japanese white rabbits (n=24) were randomly divided into 2 equal groups: A sham group and a SAH group. Neurological scores were evaluated for 7 days following SAH. Basilar artery (BA) diameters were measured using MRA preoperatively and 7 days postoperatively. Rabbits were sacrificed 7 days following SAH and the BA diameter of each rabbit was determined using histological evaluation. Compared with the Sham group, neurological function was significantly reduced in the SAH group at all time points (P<0.05). Furthermore, the BA diameter was significantly smaller in the SAH group on day 7 compared with the baseline measurement (P<0.05). No significant difference was observed between histological and MRA findings in either group at day 7. Histological changes in the hippocampus consistent with ischemia were observed in the SAH group. Hippocampal ischemia was also identified in the SAH group via MRA and there was no difference in detection rates following the use of MRA and histochemistry. MRA appears to be an effective method for assessing vasospasms of the BA and ischemic changes to the hippocampus in a rabbit model of SCVS. Furthermore, the animal model used in the present study may be beneficial for the future study of SCVS.

Low-dose erythropoietin treatment is not associated with clinical benefits in severely anaemic Jehovah's Witnesses: a plea for a change

BACKGROUND

Jehovah's Witnesses who refuse blood transfusion have high mortality. Erythropoietin (EPO) has been used as an alternative to blood transfusion. The optimal dosing of EPO in anaemic Jehovah's Witnesses is unknown. The aim of our study was to evaluate the clinical benefits of treatment with a low dose (<600 IU/kg/week) of epoietin beta (EPO-β).

MATERIALS AND METHODS

This was an observational study, retrospectively considering a 10-year period during which 3,529 adult Jehovah's Witnesses with a total of 10,786 hospital admissions were identified from databases of four major public hospitals in New Zealand. Patients with severe symptomatic anaemia (haemoglobin <80 g/L) who were unable to tolerate physical activity were included in the study. Patients treated without EPO were assigned to the conventional therapy group and those treated with EPO to the EPO treatment group.

RESULTS

Ninety-one Jehovah's Witnesses met the eligibility criteria. Propensity score matching yielded a total of 57 patients. Patients treated with conventional therapy and those treated with EPO had similar durations of severe anaemia (average difference 6.25 days, 95% confidence interval [CI]: -3.77-16.27 days; p=0.221). The mortality rate among Jehovah's Witnesses treated with conventional therapy was 4.68 per year (95% CI: 2.23-9.82), while that in those treated with EPO was 2.77 per year (95% CI: 0.89-8.60). Treatment with EPO was associated with a mortality ratio of 0.59 (95% CI: 0.1-2.6; p=0.236). Both groups of patients had similar in-hospital survival (p=0.703).

DISCUSSION

Treatment with low-dose EPO-β was not associated with either shorter duration of severe anaemia or a reduction in mortality.

Erythropoietin for the Treatment of Subarachnoid Hemorrhage: A Feasible Ingredient for a Successful Medical Recipe

Subarachnoid hemorrhage (SAH) following aneurysm bleeding accounts for 6% to 8% of all cerebrovascular accidents. Although an aneurysm can be effectively managed by surgery or endovascular therapy, delayed cerebral ischemia is diagnosed in a high percentage of patients resulting in significant morbidity and mortality. Cerebral vasospasm occurs in more than half of all patients after aneurysm rupture and is recognized as the leading cause of delayed cerebral ischemia after SAH. Hemodynamic strategies and endovascular procedures may be considered for the treatment of cerebral vasospasm. In recent years, the mechanisms contributing to the development of vasospasm, abnormal reactivity of cerebral arteries and cerebral ischemia following SAH, have been investigated intensively. A number of pathological processes have been identified in the pathogenesis of vasospasm, including endothelial injury, smooth muscle cell contraction from spasmogenic substances produced by the subarachnoid blood clots, changes in vascular responsiveness and inflammatory response of the vascular endothelium. To date, the current therapeutic interventions remain ineffective as they are limited to the manipulation of systemic blood pressure, variation of blood volume and viscosity and control of arterial carbon dioxide tension. In this scenario, the hormone erythropoietin (EPO) has been found to exert neuroprotective action during experimental SAH when its recombinant form (rHuEPO) is administered systemically. However, recent translation of experimental data into clinical trials has suggested an unclear role of recombinant human EPO in the setting of SAH. In this context, the aim of the current review is to present current evidence on the potential role of EPO in cerebrovascular dysfunction following aneurysmal subarachnoid hemorrhage.

Safety of Early High-Dose Recombinant Erythropoietin for Neuroprotection in Very Preterm Infants

OBJECTIVE

To investigate the safety and short term outcome of high dose recombinant human erythropoietin (rhEpo) given shortly after birth and subsequently over the first 2 days for neuroprotection to very preterm infants.

STUDY DESIGN

Randomized, double masked phase II trial. Preterm infants (gestational age 26 0/7-31 6/7 weeks) were given rhEpo (nt = 229; 3000 U/kg body weight) or NaCl 0.9% (nc = 214) intravenously at 3, 12-18, and 36-42 hours after birth.

RESULTS

There were no relevant differences between the groups for short-term outcomes such as mortality, retinopathy of prematurity, intraventricular hemorrhage, sepsis, necrotizing enterocolitis, and bronchopulmonary dysplasia. At day 7-10, we found significantly higher hematocrit values, reticulocyte, and white blood cell counts, and a lower platelet count in the rhEpo group.

CONCLUSIONS

Early high-dose rhEpo administration to very premature infants is safe and causes no excess in mortality or major adverse events.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00413946.

Attenuation of cerebral vasospasm and secondary injury by testosterone following experimental subarachnoid hemorrhage in rabbit

BACKGROUND

The vasodilatator effects of testosterone have been widely studied and demonstrated. Based on previous studies of these vasodilatatory activities, we hypothesized that testosterone might have potential effects on subarachnoid hemorrhage-induced cerebral vasospasm.

METHODS

Thirty-two adult male New Zealand white rabbits were randomly divided into four groups of eight rabbits in each group: group 1 (control); group 2 (subarachnoid hemorrhage); group 3 (subarachnoid hemorrhage + vehicle); and group 4 (subarachnoid hemorrhage + testosterone). Testosterone (15 mg/kg, intraperitoneally) was administered 5 min after the intracisternal blood injection and continued for 72 h once per day in the same dose for group 4. Animals were killed 72 h after subarachnoid hemorrhage. Basilar artery cross-sectional areas, arterial wall thicknesses, and hippocampal degeneration scores were evaluated in all groups.

RESULTS

Intraperitoneal administration of testosterone was found to attenuate cerebral vasospasm and provide neuroprotection after subarachnoid hemorrhage in rabbits. Testosterone treatment was determined to be effective at increasing the luminal area and reducing the wall thickness of the basilar artery.

CONCLUSIONS

Our findings show that testosterone has some preventive effects on SAH-induced vasospasm and secondary neuronal injury in rabbits. We propose that the vasodilatatory activity of testosterone is due to its effects on inhibiting calcium channels, activating potassium channels, augmenting nitric oxide synthesis, and inhibiting oxidant stress and inflammation.