Challenges and controversies in the medical management of primary and antithrombotic-related intracerebral hemorrhage

Activation of peroxisome proliferator-activated receptor-γ by a 12/15-lipoxygenase product of arachidonic acid: a possible neuroprotective effect in the brain after experimental intracerebral hemorrhage

OBJECTIVE In this study, the authors investigated the involvement of 15( S)-hydroxyeicosatetraenoic acid (15(S)-HETE) in the regulation of peroxisome proliferator-activated receptor-γ (PPARγ) after intracerebral hemorrhage (ICH) and its effects on hemorrhage-induced inflammatory response and oxidative stress in an experimental rodent model. METHODS To simulate ICH in a rat model, the authors injected autologous whole blood into the right striatum of male Sprague-Dawley rats. The distribution and expression of 12/15-lipoxygenase (12/15-LOX) were determined by immunohistochemistry and Western blot analysis, respectively. Immunofluorescent double labeling was used to study the cellular localization of 12/15-LOX, and 15(S)-HETE was measured with a 15(S)-HETE enzyme immunoassay kit. Neurological deficits in the animals were assessed through behavioral testing, and apoptotic cell death was determined with terminal deoxynucleotidyl transferase-mediated biotinylated dUTP nick-end labeling. RESULTS Rats with ICH had increased expression of 12/15-LOX predominantly in neurons and also in oligodendrocytes, astrocytes, and microglia. Moreover, ICH elevated production of 15(S)-HETE in the brain area ipsilateral to the blood injection. The PPARγ agonist, exogenous 15(S)-HETE, significantly increased PPARγ protein levels and increased PPARγ-regulated gene (i.e., catalase) expression in the ICH rats. Reduced expression of the gene for the proinflammatory protein nuclear factor κB coincided with decreased neuron damage and improved functional recovery from ICH. A PPARγ antagonist, GW9662, reversed the effects of exogenous 15(S)-HETE on the PPARγ-regulated genes. CONCLUSIONS The induction of 15(S)-HETE during simulated ICH suggests generation of endogenous signals of neuroprotection. The effects of exogenous 15(S)-HETE on brain hemorrhage-induced inflammatory responses and oxidative stress might be mediated via PPARγ.

Autophagy Promotes Microglia Activation Through Beclin-1-Atg5 Pathway in Intracerebral Hemorrhage

Previous study demonstrates that intracerebral hemorrhage (ICH) promotes microglia activation and inflammation. However, the exact mechanism of microglia activation induced by ICH is not clear. In this experiment, microglia autophagy was examined using electron microscopy, conversion of light chain 3(LC3), and monodansylcadaverine (MDC) staining to detect autophagic vacuoles. We found that ICH induced microglia autophagy and activation. The suppression of autophagy using either pharmacologic inhibitors (3-methyladenine, bafilomycin A1) or RNA interference in essential autophagy genes (BECN1 and ATG5) decreased the microglia activation and inflammation in ICH. Moreover, autophagy inhibitors reduced brain damage in ICH. In conclusion, these data indicate that ICH contributes to microglia autophagic activation through BECN1 and ATG5 and provide the therapeutical strategy for ICH.

Utilization of clinical practice guidelines: barriers and facilitators

Clinical practice guidelines augment clinician decision making. Researchers cite a lack of knowledge of guideline existence, complexity of guidelines, staff attitude, lack of training, time and resource constraints as reasons for nonadherence. This project sought to understand factors that promote or prevent guideline implementation at the point of care. Respondents' viewed clinical practice guidelines as valid tools necessary to standardize patient care and exhibited proficiency in synthesis and integration of guidelines into clinical decisions and treatment plans. Efficient and effective guidelines impact patient safety and quality by increasing the consistency of behavior and replacing idiosyncratic behaviors with best practices.

The relationship between the serum levels of ferritin and the radiological brain injury indices in patients with spontaneous intracerebral hemorrhage

OBJECTIVES

Preclinical studies show that iron plays a key role in mediating neuronal injury. This study was performed in order to identify the relationship between the serum level of ferritin and severity of the brain injury which occur after an Intracerebral hemorrhage (ICH).

MATERIALS AND METHODS

This was a cross sectional descriptive - analytic study, which was conducted on those patients who had suffered from an ICH and had attended Poursina Hospital. The Serum levels of ferritin were measured at admittance. A Cranial CT scan was performed at admission and also 72 hr afterward. Hematoma and edema surrounding the hematoma volumes were also measured at entrance and 72 hr afterward. Data analysis was carried out by a descriptive - analytic statistics approach and calculated later on by the Spss-20 software.

RESULTS

In this investigation, 63 patients were studied, from which 34 (54%) were male and 29 (46%) female. The average age of the patients was 69.7± 11.9 (Min 43 and Max 94 years old). A significant relationship was observed between the level of ferritin and the edema volume surrounding the hematoma at first and next 72 hr after the patients were admitted.

CONCLUSION

These results delineated the effective role of iron on the edema volume elevation. More studies are essentially urged to ascertain the clinical evaluation of the curing effect of iron chelators in those patients who suffer from ICH.

Management of intracerebral hemorrhage in the presence of anticoagulant therapy

Intracerebral hemorrhage (ICH) represents a potentially lethal form of stroke. ICH in a patient taking anticoagulant therapy presents unique diagnostic and therapeutic challenges. Specific clinical circumstances, outcomes, and evidence-based or rationally derived treatments (when the evidence is incomplete) are reviewed.

Translating basic science research to clinical application: models and strategies for intracerebral hemorrhage

Preclinical stroke models provide insights into mechanisms of cellular injury and potential therapeutic targets. Renewed efforts to standardize preclinical practices and adopt more rigorous approaches reflect the assumption that a better class of compounds will translate into clinical efficacy. While the need for novel therapeutics is clear, it is also critical that diagnostics be improved to allow for more rapid treatment upon hospital admission. Advances in imaging techniques have aided in the diagnosis of stroke, yet current limitations and expenses demonstrate the need for new and complementary approaches. Intracerebral hemorrhage (ICH) exhibits the highest mortality rate, displays unique pathology and requires specialized treatment strategies relative to other forms of stroke. The aggressive nature and severe consequences of ICH underscore the need for novel therapeutic approaches as well as accurate and expeditious diagnostic tools. The use of experimental models will continue to aid in addressing these important issues as the field attempts to translate basic science findings into the clinical setting. Several preclinical models of ICH have been developed and are widely used to recapitulate human pathology. Because each model has limitations, the burden lies with the investigator to clearly define the question being asked and select the model system that is most relevant to that question. It may also be necessary to optimize and refine pre-existing paradigms, or generate new paradigms, as the future success of translational research is dependent upon the ability to mimic human sequelae and assess clinically relevant outcome measures as means to evaluate therapeutic efficacy.