Intra-aneurysmal thrombosis as a possible cause of delayed aneurysm rupture after flow-diversion treatment

BACKGROUND AND PURPOSE

FD technology enables reconstructive repair of otherwise difficult-to-treat intracranial aneurysms. These stentlike devices may induce progressive aneurysm thrombosis without additional implants and may initiate complete reverse vessel remodeling. The associated vascular biologic processes are as yet only partially understood.

MATERIALS AND METHODS

From 12 different centers, 13 cases of delayed postprocedural aneurysm rupture were recorded and analyzed. Symptom, aneurysm location and morphology, and the time elapsed from treatment until rupture were analyzed.

RESULTS

There were 10 internal carotid and 3 basilar artery aneurysms. Mean aneurysm diameter was 22 ± 6 mm. Eleven patients were symptomatic before treatment. A single FD was used for all saccular aneurysms, while fusiform lesions were treated by using multiple devices. A supplementary loose coiling of the aneurysm was performed in 1 patient only. Ten patients developed early aneurysm rupture after FD treatment (mean, 16 days; range, 2-48 days); in 3 patients, rupture occurred 3-5 months after treatment. In all cases, most of the aneurysm cavity was thrombosed before rupture. The biologic mechanisms predisposing to rupture under these conditions are reviewed and discussed

CONCLUSIONS

FDs alone may modify hemodynamics in ways that induce extensive aneurysm thrombosis. Under specific conditions, however, instead of reverse remodeling and cicatrization, aggressive thrombus-associated autolysis of the aneurysm wall may result in delayed rupture.

Chronic kidney disease: implications for the perioperative period

End-stage renal disease (ESRD) and chronic kidney disease (CKD) are increasing health problems worldwide. In the US alone, an estimated 26 million people suffer from some form of CKD. In countries such as India and Pakistan, the prevalence of CKD is also rapidly rising. The presence of CKD is associated with increased perioperative morbidity and mortality, even when adjusted for other variables such as hypertension or diabetes. Frequently, CKD is under diagnosed, so patients and physicians are often unaware of the impaired renal function. Renal dysfunction as a predictor of perioperative outcomes is discussed together with therapeutic interventions aimed at the protection of renal function. Better interventions and diagnostic tools, such as cystatin C, are needed to further improve perioperative morbidity and mortality in patients with CKD.

Laminin promotes coagulation and thrombus formation in a factor XII-dependent manner

BACKGROUND

Laminin is the most abundant non-collagenous protein in the basement membrane. Recent studies have shown that laminin supports platelet adhesion, activation and aggregation under flow conditions, highlighting a possible role for laminin in hemostasis.

OBJECTIVE

To investigate the ability of laminin to promote coagulation and support thrombus formation under shear.

RESULTS AND METHODS

Soluble laminin accelerated factor (F) XII activation in a purified system, and shortened the clotting time of recalcified plasma in a FXI- and FXII-dependent manner. Laminin promoted phosphatidylserine exposure on platelets and supported platelet adhesion and fibrin formation in recalcified blood under shear flow conditions. Fibrin formation in laminin-coated capillaries was abrogated by an antibody that interferes with FXI activation by activated FXII, or an antibody that blocks activated FXI activation of FIX.

CONCLUSION

This study identifies a role for laminin in the initiation of coagulation and the formation of platelet-rich thrombi under shear conditions in a FXII-dependent manner.

Precision determination of the dpi<-->NN transition strength at threshold

An unusual but effective way to determine at threshold the dpi<-->NN transition strength alpha is to exploit the hadronic ground-state broadening Gamma(1s) in pionic deuterium, accessible by x-ray spectroscopy. The broadening is dominated by the true absorption channel dpi(-)-->nn, which is related to s-wave pion production pp-->dpi(+) by charge symmetry and detailed balance. Using the exotic atom circumvents the problem of Coulomb corrections to the cross section as necessary in the production experiments. Our dedicated measurement finds Gamma(1s)=(1171(-49)(+23)) meV yielding alpha=(252(-11)(+5)) microb.

Effects of simulated soil temperature on stem diameter increment of Pinus cembra at the alpine timberline: a new approach based on root zone roofing

For assessing the impact of soil temperature on tree growth in remote areas such as the alpine timberline we introduce a new method for soil temperature manipulations. This new approach is based on roofing of the rooting zone and allows either soil cooling or soil warming without significantly influencing soil water availability and the above ground microclimate.

Ruptured carotid artery aneurysms of the ophthalmic (C6) segment: clinical and angiographic long term follow-up of a multidisciplinary management strategy

BACKGROUND

The management of ruptured C6 aneurysms remains controversial. Detailed long-term outcome data are still lacking. Thus the present study provided a detailed long term follow-up for a multidisciplinary approach combining microsurgical clipping, endovascular embolisation and parent artery occlusion with/without bypass protection.

METHODS

In our single centre analysis of 64 consecutive patients, indications for microsurgery were: superior aneurysm projection, giant/large or wide necked aneurysms and aneurysms at branching sites. Indications for embolisation were: narrow necks, neck calcification, close aneurysm relation to the clinoid process or adhesion to the distal dural ring, and aneurysm location in the concavity of the carotid siphon curve.

RESULTS

23 patients (35.9%) underwent microsurgery, 38 patients (59.4%) embolisation and three patients (4.7%) parent artery occlusion under bypass protection. Retreatment was required in 20.9% (surgery 8.7%, endovascular 31.6%). Procedure related transient complications occurred in 10.9% (surgery 13.0%, endovascular 10.5%). Procedure related permanent morbidities occurred in 6.3% (surgery 8.7%, endovascular 5.3%), including visual deficits in 4.7% (surgery 4.4%, endovascular 5.3%). One endovascular patient died. Angiographic follow-up (29.2 (SD 31.9) months) revealed total aneurysm occlusion in 94.4% of the surgical and 82.9% of the endovascular patients. Clinical follow-up (58.7 (SD 47.6) months) showed 73.4% of the population reaching Glasgow Outcome Scale 4-5, these data being equivalent to the International Subarachnoid Aneurysm Trial (ISAT) outcomes.

CONCLUSIONS

Based on favourable neuroradiological and ophthalmological outcomes, microsurgery is recommended for superiorly projecting aneurysms, especially aneurysms involving the ophthalmic artery, and for giant/large or wide necked aneurysms. Based on stable aneurysm occlusion and excellent clinical outcomes, embolisation can be recommended for inferiorly/medially projecting small, narrow necked aneurysms.

Pituitary apoplexy: retrospective review of 30 patients—is surgical intervention always necessary?

The objective of this article is to review clinical outcomes in patients presenting with pituitary apoplexy and compare the results of conservative and surgical management. It took the form of a retrospective review of 30 patients (23M, 7F; age range: 17-86 years) with pituitary apoplexy diagnosed between 1988 and 2004. Presenting features included headache in 27 patients, 'collapse' in three and vomiting in 14. Complete blindness occurred in four patients, monocular blindness in two, decreased visual acuity in 12, visual field loss in 10 and ophthalmoplegia in 15. Only five had no initial visual deficit. CT was the initial mode of imaging in 22 patients: three such scans were initially reported as 'normal' and a further 10 as pituitary tumour only, with no haemorrhage. Ten patients proceeded to early pituitary surgery and 20 were managed conservatively. There was one death 24 days after admission in a patient with multiple co-morbidities. Of the six patients with blindness, three (two conservatively treated) regained partial vision. Of the remaining 19 patients with visual deficits, 10 (two surgically treated) recovered fully and eight (four surgically treated) partly so. At latest follow-up the following pituitary hormone deficiencies were identified: ACTH 19; TSH 20; testosterone 18; ADH (diabetes insipidus) eight. Later recurrence of a pituitary adenoma was observed in seven cases (including six of the 10 surgically treated patients). There was no evidence that those patients managed surgically had a better outcome. Early neurosurgical intervention may not be required in most patients presenting with pituitary apoplexy.

Intra-annual dynamics of stem CO2 efflux in relation to cambial activity and xylem development in Pinus cembra

The relationship between stem CO(2) efflux (E(S)), cambial activity and xylem production in Pinus cembra L. was determined at the timberline (1950 m a.s.l.) of the Central Austrian Alps, for 1 year. The E(S) was measured continuously from June 2006 to August 2007 using an infrared gas-analysis system. Cambial activity and xylem production were determined by repeated microcore sampling of the developing tree ring, and radial increment was monitored using automated point dendrometers. Besides temperature, the number of living tracheids and cambial cells was predominantly responsible for E(S), and E(S) normalized to 10 degrees C (E(S10)) was significantly correlated to the number of living cells throughout the year (r(2) = 0.574; P < 0.001). However, elevated E(S) and missing correlation between E(S10) and xylem production were detected during cambial reactivation in April and during transition from active phase to rest, which occurred in August and lasted until early September. Results of this study indicate that (i) during seasonal variations in cambial activity, nonlinearity between E(S) and xylem production occurs and (ii) elevated metabolic activity during transition stages in the cambial active-dormancy cycle influences the carbon budget of P. cembra. Daily radial stem increment was primarily influenced by the number of enlarging cells and was not correlated to E(S).

Line shape of the microH(3p-1s) hyperfine transitions

The (3p-1s) x-ray transition to the muonic hydrogen ground state was measured with a high-resolution crystal spectrometer. A Doppler effect broadening of the x-ray line was established which could be attributed to different Coulomb deexcitation steps preceding the measured transition. The assumption of a statistical population of the hyperfine levels of the muonic hydrogen ground state was directly confirmed by the experiment, and measured values for the hyperfine splitting can be reported. The results allow a decisive test of advanced cascade model calculations and establish a method to extract fundamental strong-interaction parameters from pionic hydrogen experiments.

A retrospective study of neurological disease in 118 rabbits

A retrospective pathological study of 118 rabbits presenting with neurological disease was conducted. Diagnoses were categorized on the basis of aetiopathogenesis as inflammatory, vascular, traumatic, metabolic-toxic, neoplastic, degenerative or idiopathic. Central nervous system (CNS) lesions were present in 85 (72.0%) of the rabbits and in most of these cases (70.3%) a causative agent was identified. The majority of animals (n=78, 66.1%) had disease of an inflammatory nature and 71 of these 78 rabbits had one of two zoonotic infectious diseases: encephalitozoonosis (n=69, 58.5%) and herpes simplex virus (HSV) encephalitis (n=2). Infections with zoonotic potential are therefore a major cause of CNS disease in the rabbit.

Cervical Spinal Chordoma with Chondromatous Component in a Dog

A 7-year-old male Belgian Shepherd dog was presented with sudden onset of lateral recumbency and tetraparesis. At the level of the third cervical vertebra, magnetic resonance imaging demonstrated an intrameningeal and intramedullary mass lesion. The animal was subsequently euthanatized. A necropsy revealed a semitranslucent solid mass infiltrating dorsal and ventral dura mater and the spinal cord. Histologic examination revealed a lobulated pleomorphic mass, mainly resembling undifferentiated cartilage interspersed by spindle-shaped and polygonal cells with highly vacuolated cytoplasm (physaliphorous cells). Immunohistochemistry of the tumor cells demonstrated dual expression of vimentin and cytokeratin. Based on the histologic and immunohistochemical results, the diagnosis of a chordoma with chondromatous component was made.

Protein C supports platelet binding and activation under flow: role of glycoprotein Ib and apolipoprotein E receptor 2

BACKGROUND

Activated protein C (APC) regulates thrombin generation and inhibits apoptosis. Endothelial protein C receptor (EPCR)-bound protein C is activated by thrombomodulin-bound thrombin. APC inactivates coagulation factors (F)Va/VIIIa and generates cytoprotective signaling downstream of protease-activated receptor-1 (PAR-1). Binding of APC to EPCR both modifies and induces PAR-1 signaling, but it is unknown if protein C interacts with cells in an alternative manner.

AIM

To determine whether platelets possess receptors for protein C that can generate intracellular signals.

RESULTS

Immobilized protein C or APC supported platelet adhesion, lamellipodia formation and elevation of intracellular Ca(2+). Adhesion of platelets to protein C or APC was inhibited by soluble recombinant apolipoprotein E receptor 2' (ApoER2') and by receptor-associated protein (RAP), an inhibitor of the low-density lipoprotein receptor family. Under shear, surface-bound protein C supported platelet adhesion and aggregation in a glycoprotein (GP)Ibalpha-dependent manner, and adhesion of platelets to immobilized protein C was abrogated by the addition of soluble forms of ApoER2' or RAP. APC bound to purified recombinant ApoER2' or GPIbalpha.

CONCLUSIONS

Our data demonstrate that activation of platelets with rapid intracellular signaling caused by binding to immobilized protein C or APC occurs via mechanisms that require ApoER2 and GPIbalpha and that APC directly binds to purified ectodomains of the receptors ApoER2 and GPIbalpha. These findings imply that protein C and APC may directly promote cell signaling in other cells by binding to ApoER2 and/or GPIbalpha.

Serum urea and total cholesterol independently predict re-hospitalisation with a cardiac-related event following an acute ST-elevation myocardial infarction

BACKGROUND

Although elevated serum urea and low serum sodium have been shown to be associated with increased short-term (30-day) mortality following an ST-elevation myocardial infarction (STEMI), little is known about the role of these biochemical markers as predictors of intermediate-term (1-year) re-hospitalisation.

METHODS

Case notes of 90 consecutively admitted patients discharged with a primary diagnosis of an STEMI were retrospectively investigated. Baseline parameters were recorded and patients' clinical course following hospital discharge was carefully reviewed up to 1-year post-STEMI. Multivariate logistic regression analysis was performed to determine the independent association between baseline parameters and 1-year re-hospitalisation.

RESULTS

The mean age of the patients was 62.8+/-1.38 years. Thirty patients (33.3%) were re-hospitalised for cardiac-related events and three patients (3.3%) died within 1 year of index STEMI. Using stepwise regression analysis, after adjusting for all independent variables, admission total cholesterol (p=0.013) and urea (p=0.04) were found to be the only significant independent predictors of re-hospitalisation or death. Admission serum sodium was non-significant (p=0.065), but only just. For each mmol/L increase in total cholesterol, a patient was 2.18 times more likely to be re-hospitalised, while for each mmol/L increase in serum urea, a patient was 1.32 times more likely to be re-hospitalised or die. When data were categorised based on high urea (> 7 mmol/L), high total cholesterol (> 5.0 mmol/L) and low sodium (< 135 mmol/L) at admission, none of these variables showed any significant increased risk of re-hospitalisation or death. This suggests that these biochemical parameters were continuously associated with risk of re-hospitalisation through the whole range of serum concentrations.

CONCLUSION

In this retrospective study, independent predictors of 1-year re-hospitalisation following an STEMI include high serum urea, raised cholesterol levels and, possibly, reduced sodium levels. These simple biomarkers can be included in patients' risk stratification when following post-STEMI patients in out-patient clinics.

Obstructive sleep apnoea is independently associated with the metabolic syndrome but not insulin resistance state

Obstructive sleep apnoea (OSA) is a cardio-metabolic disorder. Whether metabolic syndrome (MS), insulin resistance (IR) and albuminuria are independently associated with OSA is unclear, but defining the interactions between OSA and various cardiovascular (CV) risk factors independent of obesity facilitates the development of therapeutic strategies to mitigate their increased CV risks. We prospectively recruited 38 subjects with OSA and 41 controls. Anthropometric measurements, glucose, lipids, insulin and blood pressure (BP) were measured after an overnight fast. IR state was defined as homeostasis model assessment (HOMA) value >3.99 and MS diagnosed according to the International Diabetes Federation (IDF) criteria. Subjects with OSA were more obese, more insulin resistant, more hyperglycaemic, had higher Epworth score (measure of day time somnolence) and systolic blood pressure levels. The prevalence of MS was higher in OSA compared with non-OSA subjects (74% vs 24%, p < 0.001). The prevalence of microalbuminuria in both groups was negligible. Logistic regression adjusted for age, BMI and smoking showed that the patient with OSA was 5.9 (95% CI 2.0–17.6) times more likely to have MS than non-OSA patient. Triglyceride (p = 0.031), glucose (0.023) and Epworth score (0.003) values were independently associated with OSA after adjusting for BMI and other covariates whilst IR status was found not to be significant. Using the ROC curve analysis, we found that a waist circumference of >103 cm would predict MS in patients with OSA at 75–78% sensitivity and 61–64% specificity. The agreement between MS and IR state in this cohort is poor. Thus, OSA is associated with MS independent of obesity predominantly due to increased triglyceride, glucose and Epworth score values but not IR or microalbuminuria status. This observation suggests an alternative pathogenic factor mediating the increased cardiovascular risk in patients with OSA and MS, other than that due to IR. The independent link between Epworth score and MS in patients with OSA implicates the role of daytime sleepiness and chronic hypoxia as a potential mediator. Given the discordant between MS and IR state, measurement of waist is useful for predicting mainly MS but not insulin resistance status in patients with OSA. Appropriate pharmacological intervention targeting these independent factors is important in reducing the increased CV risks among patients with OSA.

Gliomatosis Cerebri in a Dog

Gliomatosis cerebri is a rare tumourous disease of the central nervous system consisting of glial cells characterized by diffuse widespread infiltration and preservation of preformed brain structures. This report describes a case of gliomatosis cerebri in a 9-year-old, male, flat-coated retriever dog with central nervous symptoms. Magnetic resonance imaging of the brain demonstrated ill-defined hyperintense zones of paramedian white matter within the right cerebral hemisphere, brainstem and cerebellum. Histological examination showed a proliferation of tumour cells in the brain structures mentioned. Glial fibrillary acidic protein-immunohistochemistry revealed a lot of fibres positively stained. Based on these findings, the alteration was diagnosed as gliomatosis cerebri.

The emerging pandemic of obesity and diabetes: are we doing enough to prevent a disaster?

Obesity is growing into a global epidemic and alarming trends are seen in Asian countries. Although obesity is defined by body mass index (BMI), waist circumference has emerged as a more specific marker of metabolic risk. BMI and waist circumference thresholds vary between ethnicities and values are lower for Asian populations. Asians are at an increased risk of developing diabetes and early death from cardiovascular complications at lower levels of BMI and waist circumference. Obesity, especially central obesity is strongly associated with development and worsening of type 2 diabetes. The developing countries may find it difficult to face a surge in diabetes with early death and loss of productivity. Therefore, early action to contain an epidemic of obesity should be considered an urgent global priority.