Identification of The Unique Subtype of Macrophages in Aneurysm Lesions at the Growth Phase.

OBJECTIVES: Recent experimental studies have defined intracranial aneurysms as a macrophage-mediated chronic inflammatory disease affecting intracranial arteries. Although there are various subtypes in macrophages, what type of macrophages is present in lesions during the disease development remains to be elucidated. METHODS: The previously-established aneurysm model of rats was used. Macrophages were labeled with the fluorescent protein and isolated by a laser-microdissection method. The comprehensive gene expression profile analyses and gene ontology analyses was then done to identify a macrophage subtype present in lesions at the growth phase. RESULTS: The gene expression profile data of total 52 macrophages infiltrating into the lesions was acquired. The principal component analysis revealed the monotonous macrophage subtype. By comparing the profile identified with one from in vitro-differentiated M0 or M1 macrophages, the macrophages in the lesions were belonged to the simple and unique subtype. Because the perception of signaling from nervous system was highlighted as up-represented terms through gene ontology analyses, the macrophage subtype in lesions at the growth phase might be differentiated under the influence of nervous system in the microenvironment. The histopathological examinations supported the above notion by confirming the presence of nerves in the adventitia. CONCLUSIONS: The findings from the present study have provided the useful insights about the macrophage subtype in aneurysm lesions at the growth phase and also proposed its ability as a therapeutic target.

[Current Knowledge on the Genetic Analysis and Development of Medical Therapy for Intracranial Aneurysms].

Genetic studies on intracranial aneurysms(IAs), like genome-wide association studies, or studies analyzing familial intracranial aneurysms, have successfully revealed the potential contribution of a set of genes to the pathology of IAs. Some of the genes may promote the formation of IAs or the process leading to rupture of the lesions through exacerbating inflammatory responses or facilitating the degenerative changes of arterial walls. Many genes or single-nucleotide polymorphisms have been identified through extensive analyses, but they can only explain one-fifth of the IA pathology; therefore, the pathogenesis of IAs is influenced by many factors, including environmental factors, and not only genetic ones. Intriguingly, a somatic mutation in the PDGFRB gene has recently been identified in more than half of the cases with fusiform aneurysms, making the development of medical therapy targeting PDGFRß signaling realistic. Nowadays, following a series of recent experimental studies, IA is considered a chronic inflammatory disease affecting intracranial arteries, indicating the potential of anti-inflammatory drugs as therapeutic drugs for the treatment of IAs. No wonder, recently published observational studies have revealed the preventive effect of statins and aspirin, with potent anti-inflammatory effects on the rupture of IAs.

Deep Learning-Derived High-Level Neuroimaging Features Predict Clinical Outcomes for Large Vessel Occlusion.

Background and Purpose- For patients with large vessel occlusion, neuroimaging biomarkers that evaluate the changes in brain tissue are important for determining the indications for mechanical thrombectomy. In this study, we applied deep learning to derive imaging features from pretreatment diffusion-weighted image data and evaluated the ability of these features in predicting clinical outcomes for patients with large vessel occlusion. Methods- This multicenter retrospective study included patients with anterior circulation large vessel occlusion treated with mechanical thrombectomy between 2013 and 2018. We designed a 2-output deep learning model based on convolutional neural networks (the convolutional neural network model). This model employed encoder-decoder architecture for the ischemic lesion segmentation, which automatically extracted high-level feature maps in its middle layers, and used its information to predict the clinical outcome. Its performance was internally validated with 5-fold cross-validation, externally validated, and the results compared with those from the standard neuroimaging biomarkers Alberta Stroke Program Early CT Score and ischemic core volume. The prediction target was a good clinical outcome, defined as a modified Rankin Scale score at 90-day follow-up of 0 to 2. Results- The derivation cohort included 250 patients, and the validation cohort included 74 patients. The convolutional neural network model showed the highest area under the receiver operating characteristic curve: 0.81±0.06 compared with 0.63±0.05 and 0.64±0.05 for the Alberta Stroke Program Early CT Score and ischemic core volume models, respectively. In the external validation, the area under the curve for the convolutional neural network model was significantly superior to those for the other 2 models. Conclusions- Compared with the standard neuroimaging biomarkers, our deep learning model derived a greater amount of prognostic information from pretreatment neuroimaging data. Although a confirmatory prospective evaluation is needed, the high-level imaging features derived by deep learning may offer an effective prognostic imaging biomarker.

Eicosapentaenoic acid prevents the progression of intracranial aneurysms in rats.

BACKGROUND: As subarachnoid hemorrhage due to rupture of an intracranial aneurysm (IA) has quite a poor outcome despite of an intensive medical care, development of a novel treatment targeting unruptured IAs based on the correct understanding of pathogenesis is mandatory for social health. METHODS: Using previously obtained gene expression profile data from surgically resected unruptured human IA lesions, we selected G-protein coupled receptor 120 (GPR120) as a gene whose expression is significantly higher in lesions than that in control arterial walls. To corroborate a contribution of GPR120 signaling to the pathophysiology, we used an animal model of IAs and examine the effect of a GPR120 agonist on the progression of the disease. IA lesion was induced in rats through an increase of hemodynamic stress achieved by a one-sided carotid ligation and induced hypervolemia. Eicosapentaenoic acid (EPA) was used as an agonist for GPR120 in this study and its effect on the size of IAs, the thinning of media, and infiltration of macrophages in lesions were examined. RESULT: EPA administered significantly suppressed the size of IAs and the degenerative changes in the media in rats. EPA treatment also inhibited infiltration of macrophages, a hallmark of inflammatory responses in lesions. In in vitro experiments using RAW264.7 cells, pre-treatment of EPA partially suppressed lipopolysaccharide-induced activation of nuclear factor-kappa B and also the transcriptional induction of monocyte chemoattractant protein 1 (MCP-1), a major chemoattractant for macrophages to accumulate in lesions. As a selective agonist of GPR120, TUG-891, could reproduce the effect of EPA in RAW264.7 cells, EPA presumably acted on this receptor to suppress inflammatory responses. Consistently, EPA remarkably suppressed MCP-1 expression in lesions, suggesting the in vivo relevance of in vitro studies. CONCLUSIONS: These results combined together suggest the potential of the medical therapy targeting GPR120 or using EPA to prevent the progression of IAs.

Predicting Clinical Outcomes of Large Vessel Occlusion Before Mechanical Thrombectomy Using Machine Learning.

Background and Purpose- The clinical course of acute ischemic stroke with large vessel occlusion (LVO) is a multifactorial process with various prognostic factors. We aimed to model this process with machine learning and predict the long-term clinical outcome of LVO before endovascular treatment and to compare our method with previously developed pretreatment scoring methods. Methods- The derivation cohort included 387 LVO patients, and the external validation cohort included 115 LVO patients with anterior circulation who were treated with mechanical thrombectomy. The statistical model with logistic regression without regularization and machine learning algorithms, such as regularized logistic regression, linear support vector machine, and random forest, were used to predict good clinical outcome (modified Rankin Scale score of 0-2 at 90 days) with standard and multiple pretreatment clinical variables. Five previously reported pretreatment scoring methods (the Pittsburgh Response to Endovascular Therapy score, the Stroke Prognostication Using Age and National Institutes of Health Stroke Scale index, the Totaled Health Risks in Vascular Events score, the Houston Intra-Arterial Therapy score, and the Houston Intra-Arterial Therapy 2 score) were compared with these models for the area under the receiver operating characteristic curve. Results- The area under the receiver operating characteristic curve of random forest, which was the worst among the machine learning algorithms, was significantly higher than those of the standard statistical model and the best model among the previously reported pretreatment scoring methods in the derivation (the area under the receiver operating characteristic curve were 0.85±0.07 for random forest, 0.78±0.08 for logistic regression without regularization, and 0.77±0.09 for Stroke Prognostication using Age and National Institutes of Health Stroke Scale) and validation cohorts (the area under the receiver operating characteristic curve were 0.87±0.01 for random forest, 0.56±0.07 for logistic regression without regularization, and 0.83±0.00 for Pittsburgh Response to Endovascular Therapy). Conclusions- Machine learning methods with multiple pretreatment clinical variables can predict clinical outcomes of patients with anterior circulation LVO who undergo mechanical thrombectomy more accurately than previously developed pretreatment scoring methods.

Spontaneous Cerebrospinal Fluid Rhinorrhea With Meningoencephalocele Recurrence After Placement of a Lumboperitoneal Shunt: A Case Report.

Cerebrospinal fluid rhinorrhea associated with meningoencephalocele is usually treated surgically. During the perioperative period, cerebrospinal fluid diversion may be employed to control intracranial pressure, but there are few indications for this method. A 51-year-old female presented with cerebrospinal fluid rhinorrhea associated with meningoencephalocele and underwent surgical repair followed by the placement of a lumboperitoneal shunt. However, cerebrospinal fluid leakage recurred, requiring a second surgery. Lumbar drainage effectively controls intracranial pressure, but it does not cure bone defects. The use of these devices should be carefully considered based on the patient's condition.

Hypoxic microenvironment as a crucial factor triggering events leading to rupture of intracranial aneurysm.

Subarachnoid hemorrhage being the rupture of intracranial aneurysm (IA) as a major cause has quite poor prognosis, despite the modern technical advances. Thereby, the mechanisms underlying the rupture of lesions should be clarified. Recently, we and others have clarified the formation of vasa vasorum in IA lesions presumably for inflammatory cells to infiltrate in lesions as the potential histopathological alternation leading to rupture. In the present study, we clarified the origin of vasa vasorum as arteries located at the brain surface using 3D-immunohistochemistry with tissue transparency. Using Hypoxyprobe, we then found the presence of hypoxic microenvironment mainly at the adventitia of intracranial arteries where IA is formed. In addition, the production of vascular endothelial growth factor (VEGF) from cultured macrophages in such a hypoxic condition was identified. Furthermore, we found the accumulation of VEGF both in rupture-prone IA lesions induced in a rat model and human unruptured IA lesions. Finally, the VEGF-dependent induction of neovessels from arteries on brain surface was confirmed. The findings from the present study have revealed the potential role of hypoxic microenvironment and hypoxia-induced VEGF production as a machinery triggering rupture of IAs via providing root for inflammatory cells in lesions to exacerbate inflammation.

Predictors of aneurysm shrinkage after flow diversion treatment for internal carotid artery aneurysms: quantitative volume analysis with MRI.

Background and purpose: Although aneurysm shrinkage often occurs after flow diversion treatment for intracranial aneurysms, no reports have addressed the factors associated with aneurysm shrinkage. Materials and methods: This retrospective single-center study was performed to examine patients with unruptured internal carotid artery aneurysms who were treated using flow diversion and followed up by imaging for at least 12 months. The study outcome was aneurysm shrinkage (volume reduction of ≥10%) 12 months after treatment. Aneurysm volume was quantitatively assessed using the MRIcroGL software. Patient and aneurysm characteristics were statistically analyzed. Results: This study involved 81 patients with 88 aneurysms. At the 6 months, 12 months, and last follow-ups, the proportion of aneurysms that had shrunk was 50, 64, and 65%, respectively. No adjunctive coiling (odds ratio, 56.7; 95% confidence interval, 7.03-457.21; p < 0.001) and aneurysm occlusion (odds ratio, 90.7; 95% confidence interval, 8.32-988.66; p < 0.001) were significantly associated with aneurysm shrinkage. In patients treated by flow diversion with adjunctive coiling, only the volume embolization rate was a factor significantly associated with aneurysm shrinkage (p < 0.001). Its cutoff value was 15.5% according to the receiver operating characteristic curve analysis (area under the curve, 0.87; sensitivity, 0.87; specificity, 0.83). Conclusion: The rate of aneurysm shrinkage after flow diversion increased during the first 12 months after treatment, but not thereafter. No adjunctive coiling and aneurysm occlusion were predictors of aneurysm shrinkage, respectively. If adjunctive coiling is required, a volume embolization rate of ≤15.5% may be suggested for aneurysm regression.

Onset-to-treatment time and aneurysmal regression predict improvement of cranial neuropathy after flow diversion treatment in patients with symptomatic internal carotid artery aneurysms.

BACKGROUND: Although flow diversion plays a pivotal role in treating internal carotid artery aneurysms presenting with cranial neuropathy, predictors of symptom improvement have not been established. OBJECTIVE: To investigate improvement of symptoms after flow diversion treatment in patients with internal carotid artery aneurysms causing cranial neuropathy, with sufficient follow-up period. Additionally, to examine factors associated with improvement of symptoms. METHODS: This retrospective multicenter study examined patients with unruptured internal carotid artery aneurysms presenting with cranial neuropathy who were treated using flow diversion and followed up for at least 12 months. Study outcomes were transient worsening of symptoms and symptom status 12 months after treatment. Patient and aneurysm characteristics were statistically analyzed. RESULTS: Seventy-seven patients were included. Data needed for outcome analysis were available for 66 patients. At the 1-, 3-, 6-, 12-month, and last follow-ups, the proportion of patients with resolved or improved symptoms was 26% (20/77), 51% (39/77), 74% (57/77), 83% (64/77), and 79%(62/77), respectively. Symptom onset-to-treatment time <6 months (OR=24.2; 95% CI 3.09 to 188.84; p=0.002) and aneurysmal regression (OR=23.1; 95% CI 1.97 to 271.75; p=0.012) were significantly associated with symptom improvement. Transient symptom worsening and worse symptoms at 12 months occurred in 19/77 (25%) and 2/77 (3%) patients, respectively. CONCLUSIONS: The rate of cranial neuropathy symptom improvement after flow diversion increased over the first 12 months after treatment, but not thereafter. Treatment within 6 months of symptom onset and aneurysmal regression were predictors of symptom improvement.

Endothelial cell malfunction in unruptured intracranial aneurysm lesions revealed using a 3D-casted mold.

Intracranial aneurysms (IA) are major causes of devastating subarachnoid hemorrhages. They are characterized by a chronic inflammatory process in the intracranial arterial walls triggered and modified by hemodynamic force loading. Because IA lesion morphology is complex, the blood flow conditions loaded on endothelial cells in each portion of the lesion in situ vary greatly. We created a 3D-casted mold of the human unruptured IA lesion and cultured endothelial cells on this model; it was then perfused with culture media to model physiological flow conditions. Gene expression profiles of endothelial cells in each part of the IA lesion were then analyzed. Comprehensive gene expression profile analysis revealed similar gene expression patterns in endothelial cells from each part of the IA lesion but gene ontology analysis revealed endothelial cell malfunction within the IA lesion. Histopathological examination, electron microscopy, and immunohistochemical analysis indicated that endothelial cells within IA lesions are damaged and dysfunctional. Thus, our findings reveal endothelial cell malfunction in IA lesions and provided new insights into IA pathogenesis.

Induction of CCN1 in Growing Saccular Aneurysms: A Potential Marker Predicting Unstable Lesions.

Growing evidence has suggested that inflammatory responses promote the progression of saccular intracranial aneurysms (IAs). However, a biomarker predicting the progression has yet to be established. This study aimed to identify novel molecules upregulated during the progression using a previously established rat aneurysm model. In this model, aneurysms are induced at the surgically created common carotid artery (CCA) bifurcation. Based on sequential morphological data, the observation periods after the surgical manipulations were defined as the growing phase (on the 10th day) or the stable phase (on the 30th day). Total cell lysates from the CCA with or without an aneurysm lesion were prepared to perform protein array analysis. The protein array analysis revealed that the matricellular protein cellular communication network factor 1 (CCN1) is induced in lesions during the growing phase. Immunohistochemistry corroborated the significant upregulation of CCN1 in the growing phase compared with the stable phase. Simultaneously with the induction of CCN1, significant increases in the number of CD68-positive macrophages, myeloperoxidase-positive cells, and proliferating smooth muscle cells in lesions were observed. Immunohistochemistry of human IA specimens reproduced the induction of CCN1 in some lesions. These findings imply a potential role of CCN1 as a marker predicting the progression of saccular aneurysms.

Hemodynamic Force as a Potential Regulator of Inflammation-Mediated Focal Growth of Saccular Aneurysms in a Rat Model.

Past studies have elucidated the crucial role of macrophage-mediated inflammation in the growth of intracranial aneurysms (IAs), but the contributions of hemodynamics are unclear. Considering the size of the arteries, we induced de novo aneurysms at the bifurcations created by end-to-side anastomoses with the bilateral common carotid arteries in rats. Sequential morphological data of induced aneurysms were acquired by magnetic resonance angiography. Computational fluid dynamics analyses and macrophage imaging by ferumoxytol were performed. Using this model, we found that de novo saccular aneurysms with a median size of 3.2 mm were induced in 20/45 (44%) of animals. These aneurysms mimicked human IAs both in morphology and pathology. We detected the focal growth of induced aneurysms between the 10th and 17th day after the anastomosis. The regional maps of hemodynamic parameters demonstrated the area exposed to low wall shear stress (WSS) and high oscillatory shear index (OSI) colocalized with the regions of growth. WSS values were significantly lower in the growing regions than in ones without growth. Macrophage imaging showed colocalization of macrophage infiltration with the growing regions. This experimental model demonstrates the potential contribution of low WSS and high OSI to the macrophage-mediated growth of saccular aneurysms.

The Bilateral Ovariectomy in a Female Animal Exacerbates the Pathogenesis of an Intracranial Aneurysm.

Considering the poor outcome of subarachnoid hemorrhage (SAH) due to the rupture of intracranial aneurysms (IA), mechanisms underlying the pathogenesis of IAs, especially the rupture of lesions, should be clarified. In the present study, a rat model of IAs in which induced lesions spontaneously ruptured resulting in SAH was used. In this model, the combination of the female sex and the bilateral ovariectomy increased the incidence of SAH, similar to epidemiological evidence in human cases. Importantly, unruptured IA lesions induced in female animals with bilateral ovariectomy were histopathologically similar to ruptured ones in the presence of vasa vasorum and the accumulation of abundant inflammatory cells, suggesting the exacerbation of the disease. The post-stenotic dilatation of the carotid artery was disturbed by the bilateral ovariectomy in female rats, which was restored by hormone replacement therapy. The in vivo study thus suggested the protective effect of estrogen from the ovary on endothelial cells loaded by wall shear stress. -estradiol or dihydrotestosterone also suppressed the lipopolysaccharide-induced expression of pro-inflammatory genes in cultured macrophages and neutrophils. The results of the present study have thus provided new insights about the process regulating the progression of the disease.

Dedifferentiation of smooth muscle cells in intracranial aneurysms and its potential contribution to the pathogenesis.

Smooth muscle cells (SMCs) are the major type of cells constituting arterial walls and play a role to maintain stiffness via producing extracellular matrix. Here, the loss and degenerative changes of SMCs become the major histopathological features of an intracranial aneurysm (IA), a major cause of subarachnoid hemorrhage. Considering the important role of SMCs and the loss of this type of cells in IA lesions, we in the present study subjected rats to IA models and examined how SMCs behave during disease progression. We found that, at the neck portion of IAs, SMCs accumulated underneath the internal elastic lamina according to disease progression and formed the intimal hyperplasia. As these SMCs were positive for a dedifferentiation marker, myosin heavy chain 10, and contained abundant mitochondria and rough endoplasmic reticulum, SMCs at the intimal hyperplasia were dedifferentiated and activated. Furthermore, dedifferentiated SMCs expressed some pro-inflammatory factors, suggesting the role in the formation of inflammatory microenvironment to promote the disease. Intriguingly, some SMCs at the intimal hyperplasia were positive for CD68 and contained lipid depositions, indicating similarity with atherosclerosis. We next examined a potential factor mediating dedifferentiation and recruitment of SMCs. Platelet derived growth factor (PDGF)-BB was expressed in endothelial cells at the neck portion of lesions where high wall shear stress (WSS) was loaded. PDGF-BB facilitated migration of SMCs across matrigel-coated pores in a transwell system, promoted dedifferentiation of SMCs and induced expression of pro-inflammatory genes in these cells in vitro. Because, in a stenosis model of rats, PDGF-BB expression was expressed in endothelial cells loaded in high WSS regions, and SMCs present nearby were dedifferentiated, hence a correlation existed between high WSS, PDGFB and dedifferentiation in vivo. In conclusion, dedifferentiated SMCs presumably by PDGF-BB produced from high WSS-loaded endothelial cells accumulate in the intimal hyperplasia to form inflammatory microenvironment leading to the progression of the disease.

Involvement of neutrophils in machineries underlying the rupture of intracranial aneurysms in rats.

Subarachnoid hemorrhage due to rupture of an intracranial aneurysm has a quite poor prognosis after the onset of symptoms, despite the modern technical advances. Thus, the mechanisms underlying the rupture of lesions should be clarified. To this end, we obtained gene expression profile data and identified the neutrophil-related enriched terms in rupture-prone lesions using Gene Ontology analysis. Next, to validate the role of neutrophils in the rupture of lesions, granulocyte-colony stimulating factor (G-CSF) was administered to a rat model, in which more than half of induced lesions spontaneously ruptured, leading to subarachnoid hemorrhage. As a result, G-CSF treatment not only increased the number of infiltrating neutrophils, but also significantly facilitated the rupture of lesions. To clarify the mechanisms of how neutrophils facilitate this rupture, we used HL-60 cell line and found an enhanced collagenolytic activity, corresponding to matrix metalloproteinase 9 (MMP9), upon inflammatory stimuli. The immunohistochemical analyses revealed the accumulation of neutrophils around the site of rupture and the production of MMP9 from these cells in situ. Consistently, the collagenolytic activity of MMP9 could be detected in the lysate of ruptured lesions. These results suggest the crucial role of neutrophils to the rupture of intracranial aneurysms; implying neutrophils as a therapeutic or diagnostic target candidate.

Case of Iatrogenic Vertebro-Vertebral Arteriovenous Fistula Treated by Combination of Double-Catheter and Balloon Anchoring Techniques.

BACKGROUND: A case of high-flow cervical vertebro-vertebral arteriovenous fistula (VVAVF), which was occluded with detachable coils by the transarterial/transvenous double-catheter technique and balloon anchoring technique, is reported. CASE DESCRIPTION: A 32-year-old male who had a history of dilated cardiomyopathy, heart failure, and arrhythmia under anticoagulation presented with a neck bruit after a right internal jugular vein puncture. A high-flow VVAVF between the right vertebral artery (VA) and vertebral vein (VV) was revealed by ultrasonography and angiography. To extirpate the shunt while preserving the right VA without using a stent to avoid antiplatelet therapy, the double-catheter technique was used to occlude the vein and shunt tightly, 1 catheter from the venous side and the other from the VA to the VV through the shunt. Finally, stabilization of the coil cage in the dilating VV was secured by placing a balloon distally as an anchor and successfully occluding the shunt with small amounts of coils only on the venous side. The shunt and cervical bruit disappeared immediately after the treatment, and no recurrence was observed. CONCLUSIONS: The double-catheter technique and balloon anchoring technique used in this case seem effective for transvenous embolization of VVAVF when preservation of the VA is desired.

Biodegradable Flow Diverter for the Treatment of Intracranial Aneurysms: A Pilot Study Using a Rabbit Aneurysm Model.

Background Herein, we report an in vivo study of a biodegradable flow diverter (BDFD) for aneurysm occlusion. Conceptually, BDFDs induce a temporal flow-diverting effect and provide a vascular scaffold for neointimal formation at the neck of the aneurysm until occlusion. This offers several potential advantages, including a reduced risk of remote ischemic complications and more treatment options in case of device failure to occlude the aneurysm. Methods and Results A BDFD consisting of 48 poly-l-lactic acid wires with radiopaque markers at both ends was prepared. An in vitro degradation test of the BDFD was performed. Thirty-six BDFDs were implanted in a rabbit aneurysm model. Digital angiography, optical coherence tomography, histopathology, and scanning electron microscopy were performed after 1, 3, and 6 months, and 1 year. The in vitro degradation test showed that the BDFD was almost degraded in 1.5 years. In the in vivo experiment, aneurysm occlusion rates were 0% at 1 month, 20% at 3 months, 50% at 6 months, and 33% at 1 year. Optical coherence tomography showed that luminal area stenosis was the highest at 3 months (16%) and decreased afterward. Immunohistochemical analysis showed that more than half of the luminal surface area was covered by endothelial cells at 1 month. Device fragmentation was not observed in any lesions. Conclusions This first in vivo study of a BDFD shows the feasibility of using BDFDs for treating aneurysms; however, a longer follow-up is required for comprehensive evaluation of the biological and mechanical behavior peculiar to biodegradable devices.

Method for inferring and extracting reliable genetic interactions from time-series profile of gene expression.

Recent advances in technologies such as DNA microarrays have provided an abundance of gene expression data on the genomic scale. One of the most important projects in the post-genome-era is the systemic identification of gene expression networks. However, inferring internal gene expression structure from experimentally observed time-series data are an inverse problem. We have therefore developed a system for inferring network candidates based on experimental observations. Moreover, we have proposed an analytical method for extracting common core binomial genetic interactions from various network candidates. Common core binomial genetic interactions are reliable interactions with a higher possibility of existence, and are important for understanding the dynamic behavior of gene expression networks. Here, we discuss an efficient method for inferring genetic interactions that combines a Step-by-step strategy (Y. Maki, Y. Takahashi, Y. Arikawa, S. Watanabe, K. Aoshima, Y. Eguchi, T. Ueda, S. Aburatani, S. Kuhara, M. Okamoto, An integrated comprehensive workbench for inferring genetic networks: Voyagene, Journal of Bioinformatics and Computational Biology 2(3) (2004) 533.) with an analysis method for extracting common core binomial genetic interactions.

The expression of 11 beta hydroxysteroid dehydrogenase in severe allergic rhinitis.

OBJECTIVE: To clarify the roles of 11 beta-HSD in resistance to glucocorticoid therapy for allergic rhinitis, a case series study was conducted. METHODS: The patient group consisted of 20 subjects with allergic rhinitis, aged from 21 to 46 years (mean age 26.5), who showed persistent GC resistance necessitating surgical removal of the inferior turbinate after 6 months' GC treatment. The patients with poor response to GC treatment for 6 months' were defined as GC resistance. The control group consisted of 10 subjects aged from 16 to 39 years (mean age 24.5) who underwent maxillofacial surgery, from whom nasal tissues were taken and who did not receive GC treatment. Nasal mucosal tissues from patients and cntorol subjects were examined immunohistochemically. The sections were washed with 0.01 M phosphate-buffered saline (PBS; pH 7.2) containing 0.15 M NaCl and 0.01% Triton X-100, and incubated for 2 h with rabbit polyclonal anti-11 beta HSD1 and 11 beta-HSD2 antibody (Santa Cruz Biotechnology, Inc., Santa Cruz, CA, USA), each diluted 1:200 in PBS containing 0.1% bovine serum albumin. Immunostained sections were assessed under an Olympus microscope with an eyepiece reticule at 200 X magnification. Cell counts are expressed as means per high-power field (0.202 mm2). Control group means (arithmetic mean ± SD) were compared with patient group means by Mann-Whitney U-test at P = 0.05. RESULTS: Although 11 beta-HSD1 was expressed to a similar extent in patients and controls, 11 beta-HSD2 was expressed significantly more in patients with severe allergic rhinitis, resulting in a increased HSD-1/HSD-2 ratio. The significantly increased expression of 11 beta-HSD2 in the nasal epithelium and submucosal inflammatory cells of patients with severe nasal allergy were observed in the present study. CONCLUSION: Our findings suggest that 11 beta-HSD2 plays an important role in resistance to glucocorticoid therapy for allergic rhinitis, and its expression might be used as an additional parameter indicating steroid resistance in allergic rhinitis.

Establishment and characterization of a human thyroid carcinoma cell line (HOTHC) producing colony stimulating factor.

A cell line designated HOTHC was established from an anaplastic carcinoma (giant cell type) of the thyroid gland of 80-year-old woman. The HOTHC line grew rapidly in multilayer without contact inhibition, and more than 120 serial passages were made within 27 months. The cells were spindle or polygonal in shape and revealed neoplastic and pleomorphic features. These cells were characterized as containing coloid droplets and poorly developed rough-endoplasmic reticulum in the cytoplasm. Doubling time was about 24 hours and plating efficiency was about 70%. The karyotype exhibits hyperploidy and marker chromosomes, and the modal chromosome number ranged between 77-90. The HOTHC cells were transplanted into the subcutis of BALB/c nude mice and produced anaplatic carcinomas (giant cell type) resembling the original tumor. The HOTHC cells produced colony stimulating factor (CSF) and caused granulocytosis in the mice.