Flow diverter stenting for intracranial aneurysms in the pediatric population: Two case reports and literature review

The Pipeline Embolization Device (PED) is a flow-diverting intraluminal device that is approved for use in adults 18 years or older with internal carotid artery aneurysms. However, it can also be used off-label in pediatric patients with aneurysms that cannot be resolved with traditional endovascular treatments. Herein, we present two cases of flow diversion in the pediatric population with complete obliteration of the aneurysm and excellent outcomes. Flow diversion has been shown to be a safe endovascular option in treating complex aneurysms in children. Larger-sized, multicenter trials are encouraged to compare outcomes between flow diversion and other aneurysm treatment options given the rarity of pediatric aneurysms.

Role of Advanced MR Imaging in Diagnosis of Neurological Malignancies: Current Status and Future Perspective

Lesions of the central nervous system (CNS) can present with numerous and overlapping radiographical and clinical features that make diagnosis difficult based exclusively on history, physical examination, and traditional imaging modalities. Given that there are significant differences in optimal treatment protocols for these various CNS lesions, rapid and non-invasive diagnosis could lead to improved patient care. Recently, various advanced magnetic resonance imaging (MRI) techniques showed promising methods to differentiate between various tumors and lesions that conventional MRI cannot define by comparing their physiologic characteristics, such as vascularity, permeability, oxygenation, and metabolism. These advanced MRI techniques include dynamic susceptibility contrast MRI (DSC), diffusion-weighted imaging (DWI), dynamic contrast-enhanced (DCE) MRI, Golden-Angle Radial Sparse Parallel imaging (GRASP), Blood oxygen level-dependent functional MRI (BOLD fMRI), and arterial spin labeling (ASL) MRI. In this article, a narrative review is used to discuss the current trends in advanced MRI techniques and potential future applications in identifying difficult-to-distinguish CNS lesions. Advanced MRI techniques were found to be promising non-invasive modalities to differentiate between paraganglioma, schwannoma, and meningioma. They are also considered promising methods to differentiate gliomas from lymphoma, post-radiation changes, pseudoprogression, demyelination, and metastasis. Advanced MRI techniques allow clinicians to take advantage of intrinsic biological differences in CNS lesions to better identify the etiology of these lesions, potentially leading to more effective patient care and a decrease in unnecessary invasive procedures. More clinical studies with larger sample sizes should be encouraged to assess the significance of each advanced MRI technique and the specificity and sensitivity of each radiologic parameter.

Case report: vertebral osteomyelitis secondary to a dental abscess

BACKGROUND

Vertebral osteomyelitis can be attributed to many factors including immunosuppression, diabetes, malignancy, collagen disease, periodontal disease, open fractures, and endoscopic procedures. Anaerobic bacteria, such as Veillonella species, are found in the oral cavity and are rarely implicated in the infection. This report describes vertebral osteomyelitis secondary to a dental abscess with positive Veillonella cultures.

CASE DESCRIPTION

A 76-year-old man presented to the hospital due to back pain with a four-day history of fever and chills. CT scans revealed several abscesses in the lumbar region as well as indications of vertebral osteomyelitis. After a psoas drain, the patient began antibiotics with a combination of ampicillin-sulbactam, metronidazole, and levofloxacin, but due to the patient's penicillin allergy, he was initially desensitized to this antibiotic for a significant period of time. Laminectomies, foraminotomies, and facetectomies were performed, but the infection spread to vertebral levels. The patient was then switched to a combination of vancomycin, metronidazole, and levofloxacin which eliminated the infection. Final laminectomy was performed with posterior segmental instrumentation and arthrodesis. Post-operatively, there were no signs of infection. The patient recovered well and regained mobility. Deeper examination of the patient's medical history revealed a severe tooth abscess immediately before the onset of bacteremia.

CONCLUSION

We believe that a delay in the onset of antibiotic treatment is what led to the initial bacteremia that ultimately took root in the lower lumbar vertebrae. To the best of our ability, we could identify only one other case that linked vertebral osteomyelitis to the oral cavity.

Trevo 2000: Results of a Large Real-World Registry for Stent Retriever for Acute Ischemic Stroke

Background Recent randomized controlled trials show benefit of thrombectomy for large vessel occlusion in stroke. Real-world data aid in assessing reproducibility of outcomes outside of clinical trials. The Trevo Retriever Registry is a multicenter, international, prospective study designed to assess outcomes in a large cohort of patients. Methods and Results The Trevo Registry is a prospective database of patients with large vessel occlusion treated with the Trevo device as the first device. The primary end point is revascularization based on modified Thrombolysis in Cerebral Infarction score and secondary end points include 90-day modified Rankin Scale, 90-day mortality, neurological deterioration at 24 hours, and device/procedure related adverse events. Year 2008 patients were enrolled at 76 centers in 12 countries. Median admission National Institutes of Health Stroke Scale was 16 (interquartile range, 11-20). Occlusion sites were internal carotid artery (17.8%), middle cerebral artery (73.5%), posterior circulation (7.1%), and distal vascular locations (1.6%). A modified Thrombolysis in Cerebral Infarction 2b or 3 was achieved in 92.8% (95% CI, 91.6, 93.9) of procedures, with 55.3% (95% CI, 53.1, 57.5) of patients achieving modified Rankin Scale ≤2 at 3 months. Patients meeting revised 2015 American Heart Association criteria for thrombectomy had a 59.7% (95% CI , 56.0; 63.4) modified Rankin Scale 0 to 2 at 3 months, whereas 51.4% treated outside of American Heart Association criteria had modified Rankin Scale 0 to 2. 51.4% (95% CI , 49.6, 55.4). Symptomatic intracranial hemorrhage rate was 1.7% (95% CI , 1.2, 2.4). Conclusions The Trevo Retriever Registry represents real-world data with stent retriever. The registry demonstrates similar reperfusion rates and outcomes in the community compared with rigorous centrally adjudicated clinical trials. Future subgroup analysis of this cohort will assist in identifying areas of future research. Clinical Trial Registration URL : https://www.clinicaltrials.gov . Unique identifier: NCT 02040259.

Charge-density-wave in 1T-TiSe2: exciton-phonon separation by femtosecond valence band dynamics

We investigate the driving mechanism leading to charge-density-wave transition in 1T-TiSe2 single crystals. Our results show that both exciton instability and phonons cooperate to develop the charge ordered phase below 202 K.

Awake Craniotomy for the Treatment of a Cortical Pseudoaneurysm in a Pregnant Patient

Neurosurgical pathologies presenting during pregnancy are uncommon. If present, the situation creates a unique diagnostic, observational, and therapeutic challenge as both lives are placed at potential risk. Surgical procedures during pregnancy are approached carefully as physiological stressors associated with surgery and anesthesia may cause fetal or maternal compromise. We present the only known case of a pseudoaneurysm treated with an awake craniotomy, allowing us to abate the risks associated with general anesthesia in pregnancy.

A female suffered a superficially penetrating gunshot wound to the head for which she underwent a craniotomy with complete neurological recovery. She had complaints of intermittent headaches, dizziness, and tingling of her hands five months thereafter. The cerebral angiogram demonstrated an 8 mm pseudoaneurysm under her craniotomy site. A surgical repair of this aneurysm was undertaken in the 23rd week of pregnancy via an awake craniotomy with regional scalp block. The aneurysm was resected without complication, and the patient tolerated the procedure without neurological deficit during or subsequent to the operation.

Cerebrovascular pathology in pregnant patients remains a difficult situation that poses challenges associated with the pathology itself as well as the anesthetic implications inherent with operative management. The neurosurgical literature demonstrates that surgical management of cerebrovascular pathology is well-tolerated in pregnancy, and our case further demonstrates the capability of utilizing an awake craniotomy for the treatment of this type of lesion without causing a residual deficit.

Ultrafast spin-polarized electron dynamics in the unoccupied topological surface state of Bi2Se3

The three-dimensional topological insulator Bi₂Se₃ presents two cone-like dispersive topological surface states centered at the [Formula: see text] point. One of them is unoccupied in equilibrium conditions and located 1.8 eV above the other one lying close to the Fermi level. In this work we employ time- and angle-resolved photoemission spectroscopy with circularly polarized pump photons to selectively track the spin dynamics of the empty topological states. We observe that spin-polarized electrons flow along the topological cone and recombine towards the unpolarized bulk states on a timescale of few tens of femtoseconds. This provides direct evidence of the capability to trigger a spin current with circularly polarized light.

Anchor technique: Use of stent retrievers as an anchor to advance thrombectomy catheters in internal carotid artery occlusions

In three recent cases of acute complete internal artery occlusions, we used stent retriever deployed through the mechanical aspiration/distal access catheters to achieve recanalization. In all cases the stent retriever was used as an anchor and supplemented mechanical thrombectomy. This report describes the technical details of the procedure and presents an alternative plan of action in difficult cases when standard thrombectomy techniques do not work.

A flexible experimental setup for femtosecond time-resolved broad-band ellipsometry and magneto-optics

A versatile experimental setup for femtosecond time-resolved ellipsometry and magneto-optical Kerr effect measurements in the visible light range is described. The apparatus is based on the pump-probe technique and combines a broad-band probing beam with an intense near-infrared pump. According to Fresnel scattering matrix formalism, the analysis of the reflected beam at different polarization states of the incident probe light allows one to determine the diagonal and the off-diagonal elements of the dielectric tensor in the investigated sample. Moreover, the pump-probe method permits to study the dynamics of the dielectric response after a short and intense optical excitation. The performance of the experimental apparatus is tested on CrO2 single crystals as a benchmark.

An innovative Yb-based ultrafast deep ultraviolet source for time-resolved photoemission experiments

Time- and angle-resolved photoemission spectroscopy is a powerful technique to study ultrafast electronic dynamics in solids. Here, an innovative optical setup based on a 100-kHz Yb laser source is presented. Exploiting non-collinear optical parametric amplification and sum-frequency generation, ultrashort pump (hν = 1.82 eV) and ultraviolet probe (hν = 6.05 eV) pulses are generated. Overall temporal and instrumental energy resolutions of, respectively, 85 fs and 50 meV are obtained. Time- and angle-resolved measurements on BiTeI semiconductor are presented to show the capabilities of the setup.

Endothelial expression of TNF receptor-1 generates a proapoptotic signal inhibited by integrin α6β1 in glioblastoma

Activation of TNF receptor 1 (TNF-R1) can generate signals that promote either apoptosis or survival. In this study, we show that these signals can be determined by the character of the extracellular matrix in the tumor microenvironment. Specifically, through studies of glioblastoma, we showed that TNFα stimulation induced apoptosis of primary brain endothelial cells (EC) attached to collagen or fibronectin (which engage integrins α2β1/α3β1 and α5β1, respectively), but did not induce apoptosis of ECs attached to laminin (which engages integrins α6β1 and α3β1). TNF-R1 expression was significantly higher in ECs in glioblastoma (GBM) tumors compared with ECs in normal brain specimens. TNFα was also expressed in GBM tumor-associated ECs, which was associated with longer patient survival. ECs plated on anti-integrin α2 or α3 antibody were susceptible to TNFα-induced apoptosis, whereas those plated on anti-integrin α6 antibody were not. Moreover, the ECs plated on laminin, but not collagen, expressed cellular FLICE inhibitory protein (cFLIP) and TNFα stimulation of laminin-attached cells in which cFLIP had been downregulated resulted in the induction of apoptosis. In contrast, attachment to laminin did not induce cFLIP expression in GBM tumor stem cells. Together, our findings indicate that the laminin receptor integrin α6β1 promotes the survival of brain ECs by inhibiting prodeath signaling by TNF-R1, in part by inducing cFLIP expression.

Tumor-associated alterations in caspase-14 expression in epithelial malignancies

PURPOSE

Caspase-14 is unique among caspase family proteases in that its proteolytic processing has been principally associated with epithelial cell differentiation rather than apoptosis or inflammation. We investigated caspase-14 expression in several types of human epithelial malignancy by immunohistochemistry, correlating results with stage, histologic grade, and patient survival.

EXPERIMENTAL DESIGN

Tumor-associated alterations in caspase-14 expression were observed for cervical, ovarian, breast, gastric, and colon cancers.

RESULTS

In cervical (n = 445), ovarian (n = 91), and colon (n = 106) specimens, expression of caspase-14 was significantly reduced in cancers compared with normal epithelium. Decreases in caspase-14 immunopositivity correlated with the histologic progression of cervical cancer (P < 0.0001, ANOVA). In localized gastric cancers, caspase-14 immunostaining was significantly lower in poorly differentiated tumors compared with well-differentiated tumors (P = 0.02, Pearson's chi(2) analysis). Lower caspase-14 expression was associated with advanced clinical stage in ovarian cancer (P = 0.04, ANOVA) and with shorter overall survival among ovarian cancer patients with serous tumors (n = 62) in both univariate (P = 0.005) and multivariate (P = 0.03) analysis. Lower caspase-14 expression correlated with shorter overall survival among patients with T(3)N(0)M(0) stage gastric cancers (n = 94; P = 0.006, log-rank test). In contrast to cervical, ovarian, and colon cancers, caspase-14 expression was increased in ductal carcinoma in situ and invasive cancers compared with normal mammary epithelium (P = 0.001, t test).

CONCLUSIONS

The findings reveal tumor-specific alterations in caspase-14 expression and suggest that differences in its expression may define subsets of epithelial cancers with distinct clinical behaviors.

Matrix metalloproteinase-26 is associated with estrogen-dependent malignancies and targets alpha1-antitrypsin serpin

Proteases exert control over cell behavior and affect many biological processes by making proteolytic modification of regulatory proteins. The purpose of this paper is to describe novel, important functions of matrix metalloproteinase (MMP)-26. alpha1-Antitrypsin (AAT) is a serpin, the primary function of which is to regulate the activity of neutrophil/leukocyte elastase. Insufficient antiprotease activity because of AAT deficiency in the lungs is a contributing factor to early-onset emphysema. We recently discovered that AAT is efficiently cleaved by a novel metalloproteinase, MMP-26, which exhibits an unconventional PH(81)CGVPD Cys switch motif and is autocatalytically activated in cells and tissues. An elevated expression of MMP-26 in macrophages and polymorphonuclear leukocytes supports the functional role of MMP-26 in the AAT cleavage and inflammation. We have demonstrated a direct functional link of MMP-26 expression with an estrogen dependency and confirmed the presence of the estrogen-response element in the MMP-26 promoter. Immunostaining of tumor cell lines and biopsy specimen microarrays confirmed the existence of the inverse correlations of MMP-26 and AAT in cells/tissues. An expression of MMP-26 in the estrogen-dependent neoplasms is likely to contribute to the inactivation of AAT, to the follow-up liberation of the Ser protease activity, and because of these biochemical events, to promote matrix destruction and malignant progression. In summary, we hypothesize that MMP-26, by cleaving and inactivating the AAT serpin, operates as a unique functional link that regulates a coordinated interplay between Ser and metalloproteinases in estrogen-dependent neoplasms.

Expression of Bcl-2 family member Bid in normal and malignant tissues

Bid is the only known Bcl-2 family member that can function as an agonist of proapoptotic Bcl-2-related proteins such as Bax and Bak. Expression of the proapoptotic Bcl-2 family protein Bid was assessed by immunoblotting and immunohistochemical methods in normal murine and human tissues, and in several types of human cancers and tumor cell lines. Bid expression in normal tissues varied widely, with prominent Bid immunostaining occurring in several types of short-lived cells (e.g., germinal center B cells, peripheral blood granulocytes, differentiated keratinocytes) and in apoptosis-sensitive cells (e.g., adult neurons). Analysis of Bid expression by immunostaining of 100 colon, 95 ovarian, and 254 prostate cancers, as well as 59 brain tumors and 50 lymphomas, revealed evidence of altered Bid regulation in some types of cancers. Correlations with clinical outcome data revealed association of higher levels of Bid with longer recurrence-free survival in men with locally advanced (T3 stage) prostate cancer (P=0.04). Immunoblot analysis of Bid protein levels in the NCI's panel of 60 human tumor cell lines revealed a correlation between higher levels of Bid and sensitivity to ribonucleotide reductase (RR)-inhibiting drugs (P<0.0005). Overexpression of Bid in a model tumor cell line by gene transfection resulted in increased sensitivity to apoptosis induction by a RR inhibitor. Taken together, these observations suggest a potential role for Bid in tumor responses to specific chemotherapeutic drugs, and lay a foundation for future investigations of this member of the Bcl-2 family in healthy and diseased tissues.

The energy expenditure of female carpet weavers and rural women in Iran

The energy cost of individual activities and the daily energy expenditure of female carpet weavers and villagers were measured in Iranian villages and in the town of Isfahan as part of a series of studies to assess the validity for the population of past and present FAO recommended energy allowances. The energy cost of typical activities was measured by indirect calorimetry using Max-Planck respirometers. Daily energy expenditure was assessed using these figures combined with a 24-hr activity diary. The results of standard activity values are compared with other published values for Europeans and populations of countries with hot climates. The mean daily energy expenditure for both groups was in the order of 2000 kcal/day, below but close to the FAO recommendations which appear valid for rural women in a large part of the country but are probably an underestimate for areas where the participation of women in agriculture is greater.

The energy expenditure of Iranian agricultural workers

The energy cost of agricultural and standard activities and the daily energy expenditure of male agricultural workers were measured during different seasons in Iranian villages to assess the validity of past and present Food and Agricultural Organization recommended energy allowances for that population. Studies included low income farmers in a village representative of those around the central desert where harvesting takes place under conditions of extreme summer heat. Measurements were also made during the Moslem fasting period when no food may be eaten between dawn and dusk. Energy cost of typical activities was measured by indirect calorimetry using the Max-Planck respirometer and daily energy expenditure was assessed using these figures combined with a diary of activities throughout the 24-hr period. Results of individual activity values are compared with other published figures. Comparison of daily energy expenditure of fasting subjects and nonfasting after Ramazan showed no significant difference. No significant difference was found between values of standardized activities at high summer temperatures and moderate temperatures. Mean values of daily energy expenditure during winter when activity is low are around 2600 kcal/day and for the other seasons of high activity 3400 kcal/day. These figures suggest that past and present Food and Agricultural Organization standards are low for this population.

Favism, with special reference to Iran

Fava beans (Vicia fava) are cultivated rather widely in most countries of the Eastern Mediterranean area and provide a cheap but protein-rich food that can be eaten alone, in various culinary preparations, including bread, or as a dietary supplement. However, the ingestion of fava beans may induce a haemolytic disease-favism-in some susceptible individuals and this might appear to limit the use of this pulse crop in those regions where favism occurs frequently. The uses of fava beans in Iran, the characteristics of favism and the present state of knowledge of the pathology of the disease are reviewed in this paper. Although some progress has been made in identifying the toxic substances and in explaining their mode of action, our understanding of favism is still limited. It appears that the disease is seen particularly in young children and is associated with a deficiency of glucose-6-phosphate dehydrogenase (G6PD) in the blood.