Hedgehog inhibition prolongs survival in a genetically engineered mouse model of pancreatic cancer

BACKGROUND AND AIMS

Pancreatic cancer is among the most dismal of human malignancies. Current therapeutic strategies are virtually ineffective in controlling advanced, metastatic disease. Recent evidence suggests that the Hedgehog signalling pathway is aberrantly reactivated in the majority of pancreatic cancers, and that Hedgehog blockade has the potential to prevent disease progression and metastatic spread.

METHODS

Here it is shown that the Hedgehog pathway is activated in the Pdx1-Cre;LsL-Kras(G12D);Ink4a/Arf(lox/lox) transgenic mouse model of pancreatic cancer. The effect of Hedgehog pathway inhibition on survival was determined by continuous application of the small molecule cyclopamine, a smoothened antagonist. Microarray analysis was performed on non-malignant human pancreatic ductal cells overexpressing Gli1 in order to screen for downstream Hedgehog target genes likely to be involved in pancreatic cancer progression.

RESULTS

Hedgehog inhibition with cyclopamine significantly prolonged median survival in the transgenic mouse model used here (67 vs 61 days; p = 0.026). In vitro data indicated that Hedgehog activation might at least in part be ascribed to oncogenic Kras signalling. Microarray analysis identified 26 potential Hedgehog target genes that had previously been found to be overexpressed in pancreatic cancer. Five of them, BIRC3, COL11A1, NNMT, PLAU and TGM2, had been described as upregulated in more than one global gene expression analysis before.

CONCLUSION

This study provides another line of evidence that Hedgehog signalling is a valid target for the development of novel therapeutics for pancreatic cancer that might be worth evaluating soon in a clinical setting.

Efficacy of ciprofloxacin implants in treating experimental osteomyelitis

Ciprofloxacin (CFX) implants containing poly(D,L-lactide) and calcium phosphates (tricalcium phosphate and hydroxyapatite) was evaluated in 50 rabbits in an experimental osteomyelitis model. Their femoral cavity was inoculated with Staphylococcus aureus. After 2 weeks, the infected focus was cleaned out and the delivery system implanted. The infection and subsequent response to treatment were evaluated by microbiological analysis, biochemical and hematological markers, body weight, temperature, clinical signs, X-rays, and histology. Infected bone cultures, treated with CFX implants, showed reduced bacterial growth against controls. All CFX was released within 6 weeks. All animals recovered within 4 weeks. Even 12 weeks after implantation, no recurrence of infection was observed. Serum C-reactive protein, platelet, and leukocyte levels increased in all animals before treatment, and 4 weeks after it were maintained or rose in control animals, while decreased to normal levels in treated ones. Body weight was characterized by pretreatment losses, then gains during recuperation, or further loss in untreated animals; with no significant intraindividual differences in body temperature. Body weight, leucocytes, platelets, and C-reactive protein turned out to be highly useful markers for monitoring this kind of infection and its treatment. CFX implants demonstrated to be an effective therapy for S. aureus bone infection. Their efficacy was also reflected in decreasing severity of clinical signs, nonprogress of radiological signs indicative of infection, and good integration into bone structure. Histological examination revealed repair, with new bone formation extending into implants.

MR diffusion tensor imaging and fiber tracking in spinal cord arteriovenous malformations: a preliminary study

BACKGROUND AND PURPOSE

Diffusion tensor imaging (DTI) of the spinal cord in patients harboring spinal arteriovenous malformations (AVMs) was carried out to evaluate the feasibility of this new technique to determine the displacement of the spinal cord tracts and to correlate morphologic and functional DTI data (fractional anisotropy [FA] and apparent diffusion coefficient [ADC]) with the clinical symptoms.

MATERIALS AND METHODS

Nine patients with spinal cord AVMs were investigated at 1.5T using a sagittal spin-echo single-shot echo-planar generalized autocalibrating partially parallel acquisition diffusion-weighted imaging sequence. ADC and FA maps were computed in different regions of interest (both above and below the nidus), and tractography was used to visualize the course of the tracts. The data were correlated with the clinical symptoms and compared with 12 healthy control subjects.

RESULTS

At the level of the nidus, tracts were normal, shifted, separated, or interrupted but not intermingled with the nidus. Interruption of the tracts was coherent with the clinical symptoms. In patients with severe neurologic deficits, FA values caudal to the nidus showed a reduced anisotropy consistent with loss of white matter tracts.

CONCLUSIONS

We demonstrate that AVMs may interrupt, displace, or separate the fiber tracts and that clinical symptoms may be reflected by the quantitative FA results and the morphologic loss of fibers distant to the lesion. DTI with fiber tracking offers a novel approach to image spinal cord AVMs and may open a window to understand the complex pathophysiology of these lesions.

Diagnosis and endovascular treatment of pediatric spinal arteriovenous shunts

Spinal arteriovenous shunts (SAVSs) are rarely diagnosed in infants and children, but they are important clinically because morbidity can be significant. Although these lesions do not form a distinct pathologic group separate from the SAVSs seen in older patients, experience with these malformations in the pediatric population has led to the identification of several important features that are characteristic of this group of SAVSs. Association with genetic abnormalities, heritable (hereditary hemorrhagic telangiectasia) and nonheritable somatic (spinal arteriovenous metameric syndrome or Cobb syndrome), is relatively common and likely underrecognized. Male predominance is more pronounced than in the adult population. Hemorrhagic presentation is more frequent than in adults, except in extremely young children. The natural history seems to be better than previously thought, with early rehemorrhage uncommon. Despite early presentation and severe symptoms, these lesions are frequently amenable to endovascular treatment, often with anatomic cure achieved and with improvement or stabilization of symptoms after partial targeted treatment.

Vein of galen aneurysmal malformations

Different types of malformations share a dilated vein of Galen, but only one of them is a true vein of Galen aneurysmal malformation (VGAM). The optimal window of opportunity for treatment is between 4 and 5 years of months [corrected], because this allows the child to grow and mature. Heart failure and hydrocephalus respond favorably to embolization. Cerebrospinal fluid ventricular shunting, if needed, should be performed after the embolization. The transvenous approach carries significantly elevated morbidity and mortality and is rarely indicated. Anatomic cure of the VGAM is not the main goal of treatment; the ultimate goal is control of the malformation to allow the brain to mature and develop normally.

Pathologie neurovasculaire malformative de l'enfant: malformations anévrismales de la veine de Galien (MAVG), malformations artérioveineuses piales (MAVP), malformations des sinus duraux (MSD)

The purpose of this article is to give an overview of the cerebral and spinal cord pediatric malformations; we particularly describe three of them: Vein of Galen arteriovenous Malformation, Pial Arteriovenous Malformation, and Dural Sinus Malformation. We report the experience of Bicêtre since 1981 to 2003, with 317 VGAM, 302 Pial AVM and 30 DSM. We describe natural history, clinical and imaging features, endovascular management and the clinical and morphologic results. The clinical consequences of the VGAM and Pial AVM are systemic or cerebral. When they are cerebral they are mainly from hydrovenous type, as melting brain, or chronic hydrocephalus with calcifications and seizures. Depending of their angioarchitecture and amount of arteriovenous shunt, their gravity and the time of revealing are variable. Pial AVM, they carry the risk of hemorrhage, unlike VGAM. The presence of a fistula type should lead to suspect hereditary hemorrhagic telangiectasia. The main risk of DSM is hemorrhage due to thrombosis of the malformation, more than hydrovenous disorders. In VGAM, we obtain the complete cure of the shunt in 55% of case, and reduction of more than half of the shunt in 93.8%. Seventy-four percent of treated cases had a normal neurologic examination. DSM have a worse prognostic, and mortality is 38% despite treatment.

Association of cervical internal carotid artery aneurysm with ipsilateral vertebrobasilar aneurysm in two children: a segmental entity?

INTRODUCTION

A combination of cervical and intradural aneurysm in children in the absence of systemic disorders has previously not been reported.

CASE REPORT

We report two boys with an identical combination of fusiform cervical internal carotid aneurysm and ipsilaterally located vertebrobasilar aneurysm. They had no history of trauma, they did not display any personal or familial signs of systemic disease, and the testing for collagen disease was negative. The location and appearance of the aneurysms and the identical anatomical disposition in the patients indicated a non-randomly distributed segmental vulnerability.

CONCLUSION

The cases demonstrate primary morphological signs of a developmental error being expressed in two seemingly separate segments but linked by the hypoglossal artery. It suggests a segmental error related to this embryonic vessel. They also show that few phenotypes are specific for a genotypic disorder and highlight the importance of analysing different etiologies for aneurysm formation and anatomical disposition when taking treatment strategy decisions.

Growth and rupture mechanism of partially thrombosed aneurysms

SUMMARY

Within the group of giant and large aneurysms the subgroup of the so-called "partially thrombosed" aneurysms can be differentiated according to clinical and neuroimaging findings. The present study was carried out to determine the site of bleeding of these aneurysms and what implications concerning their pathomechanism can be drawn from these findings. Twenty patients aged two to 77 (mean 44) years who exhibited a partially thrombosed aneurysm that had recently bled were included. Images (MRI including T1 pre- and postcontrast and T2 weighted images in multiple planes, CT and digital subtraction angiography) and patients' charts were reviewed. MRI showed an onion-skin appearance of the thrombus in 19 patients, rim enhancement of the aneurysm wall (either partial or complete) in 17, and a perifocal edema in 16 patients. The acute hemorrhage was typically crescent-shaped and located at the periphery of the aneurysm, distant from the perfused lumen of the aneurysm within the thrombosed part of the aneurysm. The current denomination "partially thrombosed" intracranial arterial aneurysms leads to the presumption that thrombus is present endoluminal whereas in fact the site of hemorrhage is within the vessel wall. A more accurate nomination would, therefore, be "aneurysms with intramural hemorrhage". The enhancing wall and the edematous reaction of the adjacent brain parenchyma might be a sign for an inflammatory pathomechanism which is reinforced by histological and pathophysiological studies. This disease should be regarded as a clinical entity separate from saccular or non-thrombosed giant or large aneurysms.

Segmental unfused basilar artery with kissing aneurysms: report of three cases and literature review

Basilar artery "fenestration" is the result of a failed fusion of the bilateral longitudinal neural arteries and can be associated with a saccular aneurysm, which typically arises at the proximal juncture of the unfused segment. "Kissing" aneurysms at this site, i.e. two aneurysms arising from the proximal junction of the unfused segment of the basilar artery pointing anteriorly and posteriorly are reported to be exceedingly rare. We present three patients with this rare condition, all of them being treated by endovascular techniques.

Management of spontaneous haemorrhagic intracranial vertebrobasilar dissection: review of 21 consecutive cases

INTRODUCTION

Haemorrhagic intracranial vertebrobasilar dissection is an uncommon cause of nontraumatic subarachnoid haemorrhage (SAH) and accounts for only 1-10% of non-traumatic SAH. Treatment in the acute phase is considered to be essential because of the high risk of rebleeding and the consequent unfavourable outcome. However, the location, the potential for involvement of eloquent vessels and the histopathological characteristics of the vessel wall make treatment demanding from both a technical and anatomical point of view. We report our experience in the management of this disease. PATIENTS AND TREATMENTS: From 1989 to June 2006, we managed 21 patients with spontaneous haemorrhagic dissection located in the intracranial vertebrobasilar system, 13 patients were treated using an endovascular approach, 1 by surgical clipping, and 7 were managed conservatively.

RESULTS

Among the 13 patients treated endovascularly, 7 underwent proximal occlusion, 4 underwent parent artery embolization at the site of dissection, and 2 underwent endovascular trapping. Severe, treatment-related complications due to dislodgement of the thrombus during the procedure occurred in 1 patient, who then died from brainstem ischaemia. One patient died from severe pneumonia and one patient was left disabled from vasospastic ischaemia resulting from severe initial SAH. The remaining 10 patients had satisfactory outcomes: none rebled after treatment and when discharged they had Karnovsky scores of 80-100. Of the 7 conservatively treated patients, three died of rebleeding and four were discharged with Karnovsky scores of 50-100. One patient, who was treated surgically, was discharged with a Karnovsky of 90.

CONCLUSION

The high rate of rebleeding and consequent mortality among the patients treated conservatively argues for treatment in the acute phase. Treatment should be guided by each patient's angiomorphology, clinical condition and the experience of the neurosurgical/neuroradiological team. Options include endovascular or surgical trapping of the dissection and proximal occlusion and embolisation of the parent artery at the site of the dissection.

Segmental Neurovascular Syndromes in Children

The concept of segmental vascular syndromes with different, seemingly unrelated, diseases is based on the embryology of the neural crest and the mesoderm migration of cells that share the same metameric origin. Migrating patterns of these cells link the brain, the cranial bones, and the face on the same side. A somatic mutation developing in the region of the neural crest or the adjacent cephalic mesoderm before migration can, therefore, be postulated to produce arterial or venous metameric syndromes, including PHACES, CAMS, Cobb syndrome, and Sturge-Weber syndrome. Although these diseases may be rare, their relationships among each other and their postulated linkage with the development of the neural crest and the cephalic mesoderm may shed light on the complex pathology and etiology of various cerebral vascular disorders.

Multiple mirror-like intracranial aneurysms. Report of a case and review of the literature

While multiple intracranial arterial aneurysms occur in 26.4% of patients with aneurysms, in our practice bilateral mirror-like aneurysms are encountered in 9.4% of patients. Multiple mirror aneurysms in the same patient are exceedingly rare. We report a case of mirror-like middle cerebral artery aneurysms associated with mirror-like posterior inferior cerebellar arteries aneurysms and discuss their significance. Although an exceptional finding, multiple mirror-like aneurysms may shed light on the vulnerability of different arterial segments to specific diseases.

Spontaneous intracerebral hemorrhage caused by an unusual association of developmental venous anomaly and arteriovenous malformation

SUMMARY

We describe three patients who presented with spontaneous intracerebral hemorrhage resulting from the close association of developmental venous anomaly (DVA) and arteriovenous malformation (AVM). Angioarchitecturally, either the DVA formed the draining pathway for the AVM or they shared a common venous channel. The AVMs were treated by targeted embolization and the DVAs were carefully preserved. It is suggested that the unusual association of an AVM with the less flexible DVA was the cause of hemorrhage.

Spontaneous mirror dissections of cervicocephalic arteries. Pathomechanical considerations

SUMMARY

While so-called twin or mirror aneurysms constitute an established subgroup of multiple aneurysms, simultaneous spontaneous mirror dissections of cervicocephalic artery have not yet been reported as a particular entity. Among the patients treated at our institution since 1989, we identified 74 patients with spontaneous, nontraumatic dissections. Six of these cases presented with simultaneous bilateral dissections and four of the six patients had mirror dissections. Acute or chronic headache was present in all four cases. Additional clinical presentations consisted of impaired consciousness, cranial nerve palsy, and tinnitus. Angiography revealed irregular stenosis, dilatation or aneurysms located in the cervical ICA (internal carotid artery), VA (vertebral artery), or MCA (middle cerebral artery) without evident location bias. Although mirror dissections seems to be an exceptional finding, they may shed light on the vulnerability of different arterial segments to specific diseases. Similar to arterial aneurysm formation, pathogenesis of mirror dissection may involve an underlying "shared defect" in the endothelial cells, since these cells demonstrate a bilateral distribution during embryological development. This particular distribution therefore also provides a chronicle trail of the first trigger striking during embryonic development and demonstrates the segmental vulnerability to highly specific triggers.

Music for pain relief

BACKGROUND

The efficacy of music for the treatment of pain has not been established.

OBJECTIVES

To evaluate the effect of music on acute, chronic or cancer pain intensity, pain relief, and analgesic requirements.

SEARCH STRATEGY

We searched The Cochrane Library, MEDLINE, EMBASE, PsycINFO, LILACS and the references in retrieved manuscripts. There was no language restriction.

SELECTION CRITERIA

We included randomized controlled trials that evaluated the effect of music on any type of pain in children or adults. We excluded trials that reported results of concurrent non-pharmacological therapies.

DATA COLLECTION AND ANALYSIS

Data was extracted by two independent review authors. We calculated the mean difference in pain intensity levels, percentage of patients with at least 50% pain relief, and opioid requirements. We converted opioid consumption to morphine equivalents. To explore heterogeneity, studies that evaluated adults, children, acute, chronic, malignant, labor, procedural, or experimental pain were evaluated separately, as well as those studies in which patients chose the type of music.

MAIN RESULTS

Fifty-one studies involving 1867 subjects exposed to music and 1796 controls met inclusion criteria. In the 31 studies evaluating mean pain intensity there was a considerable variation in the effect of music, indicating statistical heterogeneity ( I(2) = 85.3%). After grouping the studies according to the pain model, this heterogeneity remained, with the exception of the studies that evaluated acute postoperative pain. In this last group, patients exposed to music had pain intensity that was 0.5 units lower on a zero to ten scale than unexposed subjects (95% CI: -0.9 to -0.2). Studies that permitted patients to select the music did not reveal a benefit from music; the decline in pain intensity was 0.2 units, 95% CI (-0.7 to 0.2). Four studies reported the proportion of subjects with at least 50% pain relief; subjects exposed to music had a 70% higher likelihood of having pain relief than unexposed subjects (95% CI: 1.21 to 2.37). NNT = 5 (95% CI: 4 to 13). Three studies evaluated opioid requirements two hours after surgery: subjects exposed to music required 1.0 mg (18.4%) less morphine (95% CI: -2.0 to -0.2) than unexposed subjects. Five studies assessed requirements 24 hours after surgery: the music group required 5.7 mg (15.4%) less morphine than the unexposed group (95% CI: -8.8 to -2.6). Five studies evaluated requirements during painful procedures: the difference in requirements showed a trend towards favoring the music group (-0.7 mg, 95% CI: -1.8 to 0.4).

AUTHORS' CONCLUSIONS

Listening to music reduces pain intensity levels and opioid requirements, but the magnitude of these benefits is small and, therefore, its clinical importance unclear.

The anastomotic venous circle of the base of the brain

SUMMARY

Adjacent to the arterial circle of Willis at the base of the brain, there is an anastomotic circle of veins linking the right and left halves of the cerebral deep venous system. This venous circle is formed by anterior and posterior transverse anastomotic channels (the anterior and posterior communicating veins), and paramedian longitudinal vessels (the basal veins of Rosenthal). This collateral venous network has received considerably less attention than its arterial counterpart, but is its functional homologue. Although inconstant, it can be seen readily with current neuroimaging techniques including three-dimensional digital subtraction venographic phase 3D arteriography (3D-DSV) and CT venography (CTV). The venous circle represents a route of contralateral venous drainage that may become important, particularly when segments of the basal vein are absent (with or without complex DVA), or in high flow states including arteriovenous shunts that access the deep venous system.We review the gross anatomy and provide examples of the radiologic imaging of this venous circle.