Periodontal Pathogens Promote Foam Cell Formation by Blocking Lipid Efflux

Foam cells are one of the major cellular components of atherosclerotic plaques, within which the trace of periodontal pathogens has also been identified in recent studies. In line with these findings, the correlation between periodontitis and atherosclerotic cardiovascular incidences has been repetitively supported by evidence from a number of experimental studies. However, the direct role of periodontal pathogens in altered cellular signaling underlying such cardiovascular events has not been clearly defined. To determine the role of periodontal pathogens in the pathogenesis of atherosclerosis, especially in the evolution of macrophages into foam cells, we monitored the pattern of lipid accumulation within macrophages in the presence of periodontal pathogens, followed by characterization of these lipids and investigation of major molecules involved in lipid homeostasis. The cells were stained with the lipophilic fluorescent dye BODIPY 493/503 and Oil Red O to characterize the lipid profile. The amounts of Oil Red O-positive droplets, representing neutral lipids, as well as fluorescent lipid aggregates were prominently increased in periodontal pathogen-infected macrophages. Subsequent analysis allowed us to locate the accumulated lipids in the endoplasmic reticulum. In addition, the levels of cholesteryl ester in periodontal pathogen-infected macrophages were increased, implying disrupted lipid homeostasis. Further investigations to delineate the key messengers and regulatory factors involved in the altered lipid homeostasis have revealed alterations in cholesterol efflux-related enzymes, such as ABCG1 and CYP46A1, as contributors to foam cell formation, and increased Ca²⁺ signaling and reactive oxygen species (ROS) production as key events underlying disrupted lipid homeostasis. Consistently, a treatment of periodontal pathogen-infected macrophages with ROS inhibitors and nifedipine attenuated the accumulation of lipid droplets, further confirming periodontal pathogen-induced alterations in Ca²⁺ and ROS signaling and the subsequent dysregulation of lipid homeostasis as key regulatory events underlying the evolution of macrophages into foam cells.

Case management effectiveness for managing chronic illnesses in Korea: a systematic review

BACKGROUND

Case management has been adopted in Korea and been recognized as a promising care-coordination method that lowers costs and improves quality of care. However, the effectiveness of case management among individuals with chronic illnesses who reside in the community has yet to be established.

AIM

This systematic review identifies and synthesizes recent evidence of case management's effectiveness in managing chronic illnesses among adults in Korea.

METHODS

The methodology of this systematic review was guided by the Cochrane processes and PRISMA statements. A search of multiple bibliographic databases to identify studies of case management in the populations of Koreans adult with chronic illnesses was conducted. Studies that met the inclusion criteria were published in English or Korean. Nine empirical peer-reviewed studies published between 2008 and 2016 were selected for review.

RESULTS

The retrieved studies show that case management programmes in Korea for adults with chronic illness in the community were led by nurses. There was strong evidence that nurse-led case management was effective in improving psychobehavioural and objective clinical outcomes; however, results for health services utilization outcomes were mixed.

CONCLUSION

In future, research with rigorous study designs and large sample size in multiple settings are needed to further assess the effectiveness of case management in Korea.

IMPLICATIONS FOR NURSING AND HEALTH POLICY

Nurse-led case management would be of support in the care of chronic illnesses not only in Korea but also in Asian countries which share standard practice of case management with Korea. Nursing leaders should allocate resources to sponsor educational resources and practical strategies for evidence-based case management.

Retention Improvement in Fluoride Application with Cold Atmospheric Plasma

This study aimed to apply fluoride formulations to enamel with cold atmospheric plasma (CAP) and analyze the fluoride uptake, retention, and acid resistance quantitatively. Human enamel specimens were divided randomly into 2 groups: group APF1, 1.23% acidulated phosphate fluoride (APF) gel; group APF2, 1.23% APF gel with CAP. Fluoride and CAP were applied to the samples 4 times at 1-wk intervals. The specimens were also stored in artificial saliva for 4 wk to evaluate the retention of fluoride. The fluoride content on the fluoride-treated enamel was measured by an electron probe microanalyzer. To detect the resistance to demineralization, the calcium-to-phosphate ratio of the enamel samples was measured after the application of APF gel with or without CAP, followed by soaking in the demineralization solution. In groups APF1 and APF2, the amount of fluoride detected increased depending on the application frequency, and more fluoride was detected in group APF2 than in group APF1. In the experiment examining the maintenance effect, fluoride was not detected in group APF1, whereas fluoride was detected in group APF2 up to the fourth week. As for the resistance to demineralization, the calcium-to-phosphate ratio of the enamel treated with APF and CAP was higher than that treated with APF alone, and it increased with the frequency of treatment. This study suggests that the combination treatment of CAP and fluoride improves retention of fluoride on the enamel and resistance to demineralization when compared with treatment with fluoride alone.

Case management effectiveness in reducing hospital use: a systematic review

AIM

This systematic review synthesizes recent evidence of the effectiveness of case management in reducing hospital use by individuals with chronic illnesses.

BACKGROUND

Hospital use by individuals with chronic illnesses accounts for 66% of healthcare costs in the United States. its has been cited as care coordination that can reduce healthcare costs; however, its effectiveness in improving hospital use outcomes is contradictory, and no review has yet synthesized recent studies of case management with respect to hospital use outcomes.

METHODS

This systematic review followed the Cochrane processes and was guided by use of PRISMA statements. Five electronic databases were searched to obtain randomized controlled trials published within the last 10 years that evaluated case management hospital use as a primary outcome by individuals with chronic illnesses.

RESULTS

Ten studies published between 2007 and 2015 were retrieved and assessed for risk of methodological bias. All studies used case management as an intervention, focused on transitional care services and reported hospital use, including readmissions and emergency department and hospital visits, as a primary outcome. Analysis of the studies showed that case management greatly reduced hospital readmissions and emergency department visits.

LIMITATIONS

Only studies published in English were searched, and retrieved studies tended to report positive results.

CONCLUSIONS

There was strong evidence of significant reductions in hospital use with case management as an intervention. However, other results about the efffectiveness of case management remain mixed; more rigorously designed studies with case management interventions are needed.

IMPLICATIONS FOR NURSING AND HEALTH POLICY

The complexity and cost of chronic illnesses means that case management should be considered as a tool to improve quality of care and lower healthcare costs.

Distinct Enhancer Activity of Oct4 in Naive and Primed Mouse Pluripotency

Naive and primed pluripotent stem cells (PSCs) and germ cells express the Oct4 gene. The Oct4 gene contains two cis-regulatory elements, the distal enhancer (DE) and proximal enhancer (PE), which differentially control Oct4 expression in a cell-type-specific and stage-specific manner. Here, we generated double transgenic mice carrying both Oct4-ΔPE-GFP and Oct4-ΔDE-tdTomato (RFP), enabling us to simultaneously monitor the activity of DE and PE. Oct4 expression is stage-specifically regulated by DE and PE during embryonic and germ cell development. Using this dual reporter system, we successfully cultured pure populations of naive (GFP⁺RFP⁻) and primed (GFP⁻RFP⁺) PSCs. We found that GFP⁺RFP⁻ cells were metastable (not naive) in serum-containing medium; stable naive pluripotent cells were observed in medium containing two inhibitors (Meki and GSKi) but lacked serum. Finally, we suggest that the activity of Oct4 DE and PE is regulated by the repressive histone marks and DNA methylation in a cell-type-specific manner.

•

A defined model for Oct4 enhancer activity in the totipotent cycle

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Culturing pure populations of naive and primed PSCs by a double reporter system

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Altering Oct4 enhancer activity in PSCs by changing culture conditions

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Histone modification and DNA methylation regulate Oct4 enhancer activity

Community-based case management effectiveness in populations that abuse substances

BACKGROUND

The number of persons who are substance abusing has been increasing globally. A majority of them remain in their communities, untreated. Empirical studies have shown some positive impacts of case management on substance abuse. However, studies that systematically synthesize the effectiveness of community-based case management with populations that abuse substances are limited.

AIM

To review evidence of the impact of case management in improving treatment of substance abuse among adults in community settings.

METHODS

The Cochrane processes guided this systematic review. PubMed, CINAHL, PsycINFO, Ovid and the Web of Science were searched to retrieve primary studies published from 2000 to 2013. All randomized controlled trials were considered for review. The methodological quality of the studies was assessed.

RESULTS

The initial unfiltered search identified 506 references. A total of seven randomized controlled trials were selected for review. Findings show that, compared with clinical case management and usual care, community-based case management services significantly improved clients' ability to abstain from drug use, reduced social problems, supported unmet service needs and improved satisfaction. Studies also showed reduced use of healthcare services, but results were mixed.

CONCLUSIONS

There is an evidence base for practicing case management among adults who are substance abusing. In general, studies concluded that case management is an active and assertive method of care coordination for formal substance abuse treatment. Further research is needed to assess case management's cost-effectiveness and the impact of dosage on client outcomes.

IMPLICATIONS FOR NURSING POLICY

Because of the complexity of population health management across settings and over long time frames, evidence-based strategies are required to achieve health improvements. Because it provides continuous and timely care, healthcare leaders and policymakers should consider community-based case management as an important strategy for coordinating the care in populations that are substance abusing.

Establishment of a primed pluripotent epiblast stem cell in FGF4-based conditions

Several mouse pluripotent stem cell types have been established either from mouse blastocysts and epiblasts. Among these, embryonic stem cells (ESCs) are considered to represent a “naïve”, epiblast stem cells (EpiSCs) a “primed” pluripotent state. Although EpiSCs form derivatives of all three germ layers during invitro differentiation, they rarely incorporate into the inner cell mass of blastocysts and rarely contribute to chimera formation following blastocyst injection. Here we successfully established homogeneous population of EpiSC lines with efficient chimera-forming capability using a medium containing fibroblast growth factor (FGF)-4. The expression levels of Rex1 and Nanog was very low although Oct4 level is comparable to ESCs. EpiSCs also expressed higher levels of epiblast markers, such as Cer1, Eomes, Fgf5, Sox17, and T, and further showed complete DNA methylation of Stella and Dppa5 promoters. However, the EpiSCs were clustered separately from E3 and T9 EpiSC lines and showed a completely different global gene expression pattern to ESCs. Furthermore, the EpiSCs were able to differentiate into all three germ layers in vitro and efficiently formed teratomas and chimeric embryos (21.4%) without germ-line contribution.

Transgenic chicken, mice, cattle, and pig embryos by somatic cell nuclear transfer into pig oocytes

This study explored the possibility of producing transgenic cloned embryos by interspecies somatic cell nuclear transfer (iSCNT) of cattle, mice, and chicken donor cells into enucleated pig oocytes. Enhanced green florescent protein (EGFP)-expressing donor cells were used for the nuclear transfer. Results showed that the occurrence of first cleavage did not differ significantly when pig, cattle, mice, or chicken cells were used as donor nuclei (p>0.05). However, the rate of blastocyst formation was significantly higher in pig (14.9±2.1%; p<0.05) SCNT embryos than in cattle (6.3±2.5%), mice (4.2±1.4%), or chicken (5.1±2.4%) iSCNT embryos. The iSCNT embryos also contained a significantly less number of cells per blastocyst than those of SCNT pig embryos (p<0.05). All (100%) iSCNT embryos expressed the EGFP gene, as evidenced by the green florescence under ultraviolet (UV) illumination. Microinjection of purified mitochondria from cattle somatic cells into pig oocytes did not have any adverse effect on their postfertilization in vitro development and embryo quality (p>0.05). Moreover, NCSU23 medium, which was designed for in vitro culture of pig embryos, was able to support the in vitro development of cattle, mice, and chicken iSCNT embryos up to the blastocyst stage. Taken together, these data suggest that enucleated pig oocytes may be used as a universal cytoplast for production of transgenic cattle, mice, and chicken embryos by iSCNT. Furthermore, xenogenic transfer of mitochondria to the recipient cytoplast may not be the cause for poor embryonic development of cattle-pig iSCNT embryos.

Bioimaging of targeting cancers using aptamer-conjugated carbon nanodots

Using the excellent emission properties of carbon nanodots, we have developed an aptamer-conjugated imaging probe for targeting cancers.

Increased reprogramming capacity of mouse liver progenitor cells, compared with differentiated liver cells, requires the BAF complex

BACKGROUND & AIMS

Ectopic expression of certain transcription factors can reprogram somatic cells to a pluripotent state. Hematopoietic and muscle stem cells can be more efficiently reprogrammed than differentiated blood or muscle cells, yet similar findings have not been shown in other primary organ systems. Moreover, molecular characteristics of the cellular hierarchy of tissues that influence reprogramming capacities need to be delineated. We analyzed the effect of differentiation stage of freshly isolated, mouse liver cells on the reprogramming efficiency.

METHODS

Liver progenitor cell (LPC)-enriched cell fractions were isolated from adult (6-8 wk) and fetal (embryonic day 14.5) livers of mice and reprogrammed to become induced pluripotent stem (iPS) cells. Different transcription factors were expressed in liver cells, and markers of pluripotency were examined, along with the ability of iPS cells to differentiate, in vitro and in vivo, into different germ layers.

RESULTS

Fetal and adult LPCs had significantly greater reprogramming efficiency after transduction with 3 or 4 reprogramming factors. Transduction efficiency-corrected reprogramming rates of fetal LPCs were 275-fold higher, compared with unsorted fetal liver cells, when 3 reprogramming factors were transduced. The increased reprogramming efficiency of LPCs, compared with differentiated liver cells, occurred independently of proliferation rates, but was associated with endogenous expression of reprogramming factors (Klf4 and c-Myc) and BAF (Brg1/Brm associated factor)-complex members Baf155 and Brg1, which mediate epigenetic changes during reprogramming. Knockdown of BAF complex members negated the increased reprogramming efficiency of LPCs, compared with non-LPCs.

CONCLUSIONS

LPCs have intrinsic, cell proliferation-independent characteristics resulting in an increased reprogramming capacity compared to differentiated liver cells.

Epiblast stem cell subpopulations represent mouse embryos of distinct pregastrulation stages

Embryonic stem cells (ESCs) comprise at least two populations of cells with divergent states of pluripotency. Here, we show that epiblast stem cells (EpiSCs) also comprise two distinct cell populations that can be distinguished by the expression of a specific Oct4-GFP marker. These two subpopulations, Oct4-GFP positive and negative EpiSCs, are capable of converting into each other in vitro. Oct4-GFP positive and negative EpiSCs are distinct from ESCs with respect to global gene expression pattern, epigenetic profile, and Oct4 enhancer utilization. Oct4-GFP negative cells share features with cells of the late mouse epiblast and cannot form chimeras. However, Oct4-GFP positive EpiSCs, which only represent a minor EpiSC fraction, resemble cells of the early epiblast and can readily contribute to chimeras. Our findings suggest that the rare ability of EpiSCs to contribute to chimeras is due to the presence of the minor EpiSC fraction representing the early epiblast.

Conversion of mouse epiblast stem cells to an earlier pluripotency state by small molecules

Epiblast stem cells (EpiSCs) are pluripotent cells derived from post-implantation late epiblasts in vitro. EpiSCs are incapable of contributing to chimerism, indicating that EpiSCs are less pluripotent and represent a later developmental pluripotency state compared with inner cell mass stage murine embryonic stem cells (mESCs). Using a chemical approach, we found that blockage of the TGFβ pathway or inhibition of histone demethylase LSD1 with small molecule inhibitors induced dramatic morphological changes in EpiSCs toward mESC phenotypes with simultaneous activation of inner cell mass-specific gene expression. However, full conversion of EpiSCs to the mESC-like state with chimerism competence could be readily generated only with the combination of LSD1, ALK5, MEK, FGFR, and GSK3 inhibitors. Our results demonstrate that appropriate synergy of epigenetic and signaling modulations could convert cells at the later developmental pluripotency state to the earlier mESC-like pluripotency state, providing new insights into pluripotency regulation.

Conserved and divergent roles of FGF signaling in mouse epiblast stem cells and human embryonic stem cells

Mouse epiblast stem cells (EpiSCs) are cultured with FGF2 and Activin A, like human embryonic stem cells (hESCs), but the action of the associated pathways in EpiSCs has not been well characterized. Here, we show that activation of the Activin pathway promotes self-renewal of EpiSCs via direct activation of Nanog, whereas inhibition of this pathway induces neuroectodermal differentiation, like in hESCs. In contrast, the different roles of FGF signaling appear to be only partially conserved in the mouse. Our data suggest that FGF2 fails to cooperate with SMAD2/3 signaling in actively promoting EpiSC self-renewal through Nanog, in contrast to its role in hESCs. Rather, FGF appears to stabilize the epiblast state by dual inhibition of differentiation to neuroectoderm and of media-induced reversion to a mouse embryonic stem cell-like state. Our data extend the current model of cell fate decisions concerning EpiSCs by clarifying the distinct roles played by FGF signaling.

Generation of human-induced pluripotent stem cells in the absence of exogenous Sox2

Induced pluripotent stem cell technology has attracted enormous interest for potential application in regenerative medicine. Here, we report that a specific glycogen synthase kinase 3 (GSK-3) inhibitor, CHIR99021, can induce the reprogramming of mouse embryonic fibroblasts transduced by only two factors, Oct4 and Klf4. When combined with Parnate (also named tranylcypromine), an inhibitor of lysine-specific demethylase 1, CHIR99021 can cause the reprogramming of human primary keratinocyte transduced with the two factors, Oct4 and Klf4. To our knowledge, this is the first time that human iPS cells have been generated from somatic cells without exogenous Sox2 expression. Our studies suggest that the GSK-3 inhibitor might have a general application to replace transcription factors in both mouse and human reprogramming.

Generation of parthenogenetic induced pluripotent stem cells from parthenogenetic neural stem cells

Somatic cells can achieve a pluripotent cell state in a process called pluripotential reprogramming. Multipotent stem cells can differentiate into cells of only one lineage, but pluripotent stem cells can give rise to cells of all three germ layers of an organism. In this study, we generated induced pluripotent stem (iPS) cells from bimaternal (uniparental) parthenogenetic neural stem cells (pNSCs) by transduction with either four (4F: Oct4, Klf4, Sox2, and c-Myc) or two (2F: Oct4 and Klf4) transcription factors. The resultant maternal iPS cells, which were reprogrammed directly from pNSCs, were capable of generating germ line-competent chimeras. Interestingly, analysis of global gene expression and imprinting status revealed that parthenogenetic iPS cells clustered closer to parthenogenetic ESCs than to female ESCs, with patterns that were clearly distinct from those of pNSCs.

Phosphorylation-dependent septin interaction of Bni5 is important for cytokinesis

In budding yeast, septin plays as a scaffold to recruits protein components and regulates crucial cellular events including bud site selection, bud morphogenesis, Cdc28 activation pathway, and cytokinesis. Phosphorylation of Bni5 isolated as a suppressor for septin defect is essential to Swe1-dependent regulation of bud morphogenesis and mitotic entry. The mechanism by which Bni5 regulates normal septin function is not completely understood. Here, we provide evidence that Bni5 phosphorylation is important for interaction with septin component Cdc11 and for timely delocalization from septin filament at late mitosis. Phosphorylation-deficient bni5-4A was synthetically lethal with hof1Delta. bni5-4A cells had defective structure of septin ring and connected cell morphology, indicative of defects in cytokinesis. Two-hybrid analysis revealed that bni5-4A has a defect in direct interaction with Cdc11 and Cdc12. GFP-tagged bni5-4A was normally localized at mother-bud neck of budded cells before middle of mitosis. In contrast, at large-budded telophase cells, bni5-4A-GFP was defective in localization and disappeared from the neck approximately 2 min earlier than that of wild type, as evidenced by time-lapse analysis. Therefore, earlier delocalization of bni5-4A from septin filament is consistent with phosphorylation-dependent interaction with the septin component. These results suggest that timely delocalization of Bni5 by phosphorylation is important for septin function and regulation of cytokinesis.

Endovascular treatment of intracranial vertebral artery dissections with stent placement or stent-assisted coiling

BACKGROUND AND PURPOSE

Endovascular treatment with stent placement or stent-assisted coiling was recently introduced as an alternative to parent artery occlusion in intracranial vertebral artery dissections. We describe the efficacy and limitations of this method.

METHODS

Fourteen patients with intracranial vertebral artery dissection were treated with stent placement (10 patients) or stent-assisted coiling (4 patients). Double overlapping stents were deployed in 4 of 10 patients with stent placement alone. Angiographic follow-up at 6 to 12 months was available in 13 patients.

RESULTS

In 13 patients with dissecting aneurysm, immediate angiographic outcomes were complete occlusion (1 patient), nearly complete (2 patients), and incomplete (10 patients). Follow-up angiograms of 12 of these patients showed complete occlusion (6 patients) and incomplete (6 patients; 1 unstable and 5 stable). Complete occlusion rates in follow-up angiograms were superior in double stent placement (75%) or stent-assisted Guglielmi detachable coil (GDC) embolization to stent placement alone (0%). There were no instances of postprocedural ischemic attacks, new neurologic deficits, and no new minor or major strokes before patient discharge. On the modified Rankin scale applied in follow-up, all patients were assessed as functionally improved or of stable clinical status.

CONCLUSIONS

Intracranial vertebral artery dissections were acceptably treated with stent placement or stent-assisted coiling, and the patency could be preserved at follow-up. However, the efficiency of stent placement alone for intracranial vertebral artery dissecting aneurysm was limited. Stent-assisted coil embolization or double stent placements are a viable alternative for complete occlusion of dissecting aneurysms.

Clipping vs coiling of posterior communicating artery aneurysms with third nerve palsy

The authors investigated the evolution of third nerve palsy in patients with posterior communicating artery aneurysms who underwent coiling vs clipping. There was no statistical difference of complete third nerve palsy recovery in both treatments. Both techniques were of clinical benefit. Older age, diabetes, delayed interventions, and complete third nerve palsy at presentation indicated a poor prognosis for recovery.

Aneurysm in the penetrating artery of the distal middle cerebral artery presenting as intracerebral haemorrhage

We are recording the first reported case of a 20-year-old man with an intracerebral haemorrhage due to a ruptured aneurysm, which arose from a penetrating artery of the distal middle cerebral artery (MCA; M4 segment). Excision of the aneurysm was successfully achieved via a right pterional approach. The follow-up angiogram demonstrated filling of the parent vessel and no residual aneurysm. This report illustrates the angiographical finding of a penetrating artery aneurysm of the distal MCA and summarizes the previous reports to discuss their pathological and clinical characteristics.

Treatment of spontaneous arterial dissections with stent placement for preservation of the parent artery

BACKGROUND

A wide variety of treatment regimens have been advocated for dissections involving the intracranial arteries. Recently, the stent can be used to exclude the aneurysm from the circulation and preserve the parent artery. We evaluated the safety and efficacy of stent angioplasty for intracranial arterial dissections.

METHODS

Ten patients with spontaneous dissections, nine vertebral artery and one internal carotid artery lesions underwent endovascular treatment using stent placement as primary treatment modality. One stent placement was attempted in five patients initially. Three patients were intentionally treated with two overlapping stents which completely covered the aneurysm orifice. Two tandem stents were used in one patient to allow spanning the entire length of the dissection. Stent-assisted coil embolization was performed in one patient.

RESULTS

Of the 10 patients in whom stenting was tried, the overall success in reaching the target lesion with stents was 90%. Of the 9 patients treated with stents, stent release and positioning were considered optimal in 7 patients (77.8%) and suboptimal in two. Lesions of 8 patients were improved or stable in angiographic follow-up. However, one pseudo-aneurysm was enlarged, and subsequently, was treated by proximal occlusion using coils. There were no instances of postprocedural ischaemic attacks, new neurological deficits, and no new minor or major strokes prior to patient discharge. All parent arteries of the patient who underwent the successful procedure were preserved. On the modified Rankin scale used for the follow up, all patients were assessed as functionally improved or of stable clinical status.

CONCLUSIONS

The success in reducing dissection-induced stenosis or pseudo-aneurysm, the patency rate obtained at follow-up, and the lack of strokes (ischaemic or haemorrhagic) suggest that stent placement offers a viable alternative to complex surgical procedures or deconstructive procedures. The long-term efficacy and durability of stent placement for arterial dissection remains to be determined in a large series.

Elective stenting for symptomatic middle cerebral artery stenosis presenting as transient ischaemic deficits or stroke attacks: short term arteriographical and clinical outcome

BACKGROUND

Although stent assisted angioplasty is an effective treatment for coronary and peripheral arterial disease, its efficacy in intracranial arteriosclerotic disease has not been verified.

OBJECTIVES

To assess the radiographic and clinical outcome of stent assisted angioplasty for symptomatic middle cerebral artery (MCA) stenosis.

METHODS

We attempted stent assisted angioplasty in 14 patients with symptomatic high grade stenosis (>60%) on the proximal portion of the MCA, who had experienced either recurrent transient ischaemic attacks (TIAs) resistant to medical therapy or one or more stroke attacks. Patient records were analysed for angiographic characteristics, degree of stenosis, pre-procedural regimen of anti-platelet and/or anti-coagulation agents, use of devices, procedure related complications, pre-operative and post-operative single photon emission computed tomography (SPECT) findings, and clinical and radiographic outcomes.

RESULTS

Stent assisted angioplasty was successfully performed in 8 of 14 patients without any serious complications and unsuccessful in 2 of 14 patients due to the tortuous curve of the internal carotid artery siphon. Four patients had complications. Two patients had an arterial rupture; one patient was rescued by an additional stent and balloon tamponade, the other patient died. Complications in the other two patients included thrombotic occlusion and distal thrombosis. Residual stenosis was less than 50% in diameter in all the patients. All eight patients who underwent follow up cerebral angiography had no restenosis. Follow up SPECT showed improved perfusion in the affected MCA territory in all the tested patients with TIA and in one of three stroke patients. Using the modified Rankin Scale at follow up, four of five TIA patients and five of six stroke patients were assessed as functionally improved or having a stable clinical status.

CONCLUSION

Although the re-stenosis rate in stent assisted angioplasty seems to be better than in primary balloon angioplasty as reported previously, the complication rate is still high. Elective stenting is an alternative therapeutic method for the prevention of secondary ischaemic stroke in stroke patients with MCA stenosis, and seems to be a potentially effective but also hazardous therapeutic technique in patients with recurrent TIAs. This study indicates the need for randomised control trial data of this intervention. Additionally, long term follow up data and additional clinical experience are required to assess the durability of this procedure.

Opposite effects of pinealectomy and melatonin administration on brain damage following cerebral focal ischemia in rat

The endocrine system has been recognized as an important factor that may contribute to the outcome of stroke. We tested in rats the hypothesis that the pineal gland and/or its hormone melatonin may affect the outcome of a transient cerebral arteries occlusion (CerAO). Reversible 90 min focal ischemia was produced using a three-vessel occlusion method. Surgically or sham pinealectomized rats were exposed to CerAO 15 days after surgery. Melatonin (4 x 2.5 mg/kg: 30 min prior to onset of CerAO, immediately after recirculation was established, and 1 and 2 hr later) or its vehicle were administered intraperitoneally. The outcome of CerAO was assessed by quantitative assay of DNA damage or by Nissl staining and measurement of the infarct volume. Pinealectomy increased both the extent of DNA damage and the infarct volume; administration of melatonin to pinealectomized rats reduced both these markers of brain injury. We propose that the pineal endocrine system may influence the outcome of stroke. The mechanism of action and the pathophysiological role of this system, e.g., in aging, should be further characterized.

Dorsal internal carotid artery aneurysm treated by coil embolization--case report

A 50-year-old male presented with an extremely rare dorsal wall aneurysm of the internal carotid artery manifesting as intracerebral hemorrhage. Computed tomography demonstrated intracerebral hemorrhage on the frontal base. Magnetic resonance imaging clearly showed the hemorrhage was related to an aneurysm of the internal carotid artery. Cerebral angiography disclosed an elongated aneurysm of the dorsal wall of the internal carotid artery. The aneurysm was packed as fully as possible with Guglielmi detachable coils to achieve complete obliteration. The patient was discharged without neurological deficits. Dorsal internal carotid artery aneurysms have a high risk of premature rupture due to their unusual shape and position, adhesion to the brain tissue, and fragile neck. Direct clipping requires careful brain retraction, necessary exposure of the aneurysm, and gentle neck manipulation. Endovascular treatment is an alternative method for obliteration of the aneurysmal sac.

Hemidystonia and hemichoreoathetosis as an initial manifestation of moyamoya disease

OBJECTIVE

To describe hemidystonia and hemichoreoathetosis in an adult patient with moyamoya disease without a previous history of cerebrovascular accident.

DESIGN

Case report.

SETTING

Tertiary care center.

PATIENT

A 22-year-old woman suddenly developed dystonic spasms in her left hand and left foot after a severe emotional stress. The dyskinesia gradually subsided over the next 4 months. Five months after the onset, she suddenly developed choreoathetoid movement in her right hand and right foot.

MAIN OUTCOME AND RESULTS

The patient had both somatic and cortical sensory deficits in the right hand and right foot. Magnetic resonance imaging of the brain showed an infarction at the right putamen and lesions involving the right frontal lobe and the left frontotemporoparietal lobe. Magnetic resonance cerebral angiography showed severe stenoses of both internal carotid arteries at the supraclinoid portion and numerous collateral vessels, compatible with moyamoya disease. Single photon emission tomography of the brain showed hypoperfused areas at the right frontal and left frontotemporoparietal lobes. The choreoathetosis of the right limbs improved markedly, along with improvement of sensory deficits.

CONCLUSIONS

To our knowledge, this is the first report of an adult patient presenting with hemidystonia and hemichoreoathetosis as the initial manifestations of moyamoya disease. Arch Neurol. 2000;57:1510-1512

Suboptimal contrast-enhanced carotid MR angiography from the left brachiocephalic venous stasis

The purpose of this study was to evaluate left brachiocephalic venous stasis and its relationship to suboptimal contrast-enhanced carotid magnetic resonance angiography (MRA). Two groups of patients (group 1, 475 patients; group 2, 159 patients) were examined by contrast-enhanced carotid MRA. Dynamic images of four serial phases were obtained by a three-dimensional fast low-angle shot (3D-FLASH) MRA sequence after bolus injection of 20 ml of gadolinium chelate. In group 1, 43 (9.1%) of 475 cases failed in optimal visualization of carotid arteries because of venous stasis. Left-side injection of contrast media was significantly related to venous stasis (42/43) (P < 0.0001). The patients with venous stasis had a higher mean age (54. 8 +/- 1.5 vs. 60.7 +/- 2.9 years) and higher incidence of hypertension (52.8% vs. 72.1%; P < 0.05). Venous stasis was found at the left brachiocephalic vein (42/43). Compression of the left brachiocephalic vein between the sternum and aorta was confirmed in four cases by venography, chest computed tomography, and magnetic resonance imaging. In group 2, right-side injection did not cause venous stasis at all. The results of this study suggest that use of the right arm for contrast media injection is preferable in the absence of contraindications. J. Magn. Reson. Imaging 1999;10:503-509.

Comparison of Gadomer-17 and Gd-DTPA in image quality of contrast-enhanced MR angiographies using flow phantom model

The purpose of this study was to compare the image quality of 3D-TOF MR angiography (MRA) using Gadomer-17 with that using Gd-DTPA in a flow phantom model, and to present preliminary data about the proper dose concentration of Gadomer-17. In the visual analysis of vessel conspicuity, we compared the quality of pre- and post-contrast MIP images. For quantitative analysis, the signal intensities were measured in the axial base 3D-TOF images, and then the relative contrast enhancement was calculated. The results of our studies were that: 1. Maximal signal intensities were obtained at 1 mmol/L of Gadomer-17 and 4 mmol/L of Gd-DTPA. 2. Flow-related signal loss was decreased by Gd-DTPA proportional to the concentration, but Gadomer-17 did not show such a dose accumulative effect. In conclusion, after comparing the results of Gd-DTPA, it was clear that improved MRA images and higher signal intensities of vessels were obtained when lower concentrations of Gadomer-17 were used.

Evaluation of cerebral aneurysms with high-resolution MR angiography using a section-interpolation technique: correlation with digital subtraction angiography

BACKGROUND AND PURPOSE

The objective was to evaluate the results of high-resolution, fast-speed, section-interpolation MR angiography and digital subtraction angiography (DSA), thereby examining the potential use of a primary noninvasive screening test for intracranial aneurysms.

METHODS

The images were obtained in 39 cerebral aneurysmal lesions from 30 patients with a time-of-flight MR angiographic technique using a 1.5-T superconducting MR system. The total image volume was divided into four slabs, with 48 partitions each. To save time, only 24 phase-encoded steps were measured and interpolated to 48. The parameters used included 30/6.4 (TR/TE), a flip angle of 25 degrees , a 160x512 matrix, a field of view of 150x200, 7 minutes 42 seconds of scan time, an effective thickness of 0.7 mm, and an entire thickness of 102.2 mm. Maximum intensity projection was used for the image analysis, and a multiplanar reconstruction technique was used for patients with intracranial aneurysms.

RESULTS

Among 39 intracranial aneurysmal lesions in 30 patients, 21 were ruptured and 18 were unruptured. Twelve lesions were less than 2 mm in size, 12 were 3 to 5 mm, 12 were 6 to 9 mm, and three were larger than 10 mm. At initial examinations, 38 of 39 aneurysmal lesions were detected by both MR angiography and DSA, with 97% sensitivity. In confirming aneurysms in neck and parent vessels, multiplanar reconstruction was successful in detecting all 39 aneurysms, whereas MR angiography was successful in detecting 27 (69%) and DSA was successful in detecting 32 (82%) of the lesions.

CONCLUSION

High-resolution MR angiography with a section-interpolation technique showed equal results to those of DSA for the detection of intracranial aneurysms and may be used as a primary noninvasive screening test. In the evaluation of aneurysms in neck and parent vessels, the concurrent use of MR angiography and multiplanar reconstruction was far superior to the use of either MR angiography or DSA alone.

Recanalization of completely thrombosed giant aneurysm: case report

BACKGROUND

Spontaneous recanalization in a completely thrombosed giant aneurysm is a very rare condition.

CASE DESCRIPTION

An 18-year-old woman presented with a serpentine variety giant aneurysm of the posterior cerebral artery, in which spontaneous recanalization of a completely thrombosed lumen was demonstrated on magnetic resonance imaging and angiography. The patient was treated by trapping of the parent artery and aneurysmectomy.

CONCLUSION

This case will provide insight into the potential for spontaneous recanalization in completely thrombosed giant aneurysms.

Effects of repeated short versus single long episodes of focal ischemia on somatosensory evoked potentials and development of cerebral infarction in cats

The effects of repeated short episodes of focal ischemia at 30-minute intervals or a single equivalent long episode of focal ischemia on neuronal function and development of cerebral infarction were compared using somatosensory evoked potential (SEP) recording and 2,3,5-triphenyltetrazolium chloride staining in a cat model. Seventeen cats underwent transorbital occlusion of the middle cerebral artery (MCA), using one of three procedures: sham-operation; single 1-hour occlusion of the MCA, followed by 3 hours of recirculation; or three 20-minute occlusions of the MCA at 30-minute intervals, followed by 3 hours of recirculation. Two of six cats in the single long-term occlusion group showed recovery of SEP, whereas all six cats in the repeated short-term occlusion group showed recovery of SEP at 3 hours after recirculation. All six cats in the single long-term occlusion group had cerebral infarction of various sizes, but only one cat in the repeated short-term occlusion group developed infarction. Repeated short episodes of focal ischemia are relatively less damaging than a single equivalent long episode of focal ischemia, even if the reperfusion interval is extended to 30 minutes.

Cycloheximide reduces the size of lesion caused in rats by a photothrombotic model of brain injury

A reproducible brain lesion can be triggered in rats by treating them systematically with rose bengal and irradiating their skulls with light. This procedure is often referred to as the photothrombotic model of stroke/ injury. Recently we reported that in this model some cells show signs of apoptosis, programmed cell death. Apoptosis can be attenuated by inhibitors of macromolecular synthesis. In the work described here, we tested the hypothesis that the protein synthesis inhibitor cycloheximide will reduce the actual size of a photothrombotic brain lesion. Ten male rats were treated subcutaneously with 2.5 mg kg-1 cycloheximide; 10 rats received saline. One hour later, a photothrombotic injury was induced in the left cortex in all animals; they were sacrificed 24 h after photothrombosis. Nissl staining and computer-assisted analyses were used to assess the volume of the lesion, and to count the Nissl-positive cells. Both assays revealed significant protective action of cycloheximide treatment. In line with previous reports in which we described the occurrence of apoptosis in the model of photothrombotic brain injury our results with cycloheximide suggest that this model of focal brain ischemia can be used to test the neuroprotective efficacy of putative antiapoptotic compounds.

Increased brain damage after stroke or excitotoxic seizures in melatonin-deficient rats

The pineal hormone melatonin is neuroprotective in vitro, and in vivo it is neuroprotective when given in pharmacological doses. Consequently, it has been hypothesized that with aging, as circulating levels of melatonin in mammals normally decrease, the brain might be at increased risk of neurodegeneration. However, direct evidence that melatonin deficiency leads to increased brain vulnerability is still lacking. We created melatonin deficiency in rats by pinealectomy and induced neurodegeneration by two models of focal brain ischemia/stroke and by glutamate receptor-mediated, epilepsy-like seizures. We observed greater neurodegeneration in melatonin-deficient animals than in controls. Our results suggest that endogenous melatonin may play a neuroprotective role, and that melatonin deficiency might be a pathophysiological mechanism in neurodegenerative diseases.

Pharmacological characterization of apoptotic cell death in a model of photothrombotic brain injury in rats

We have shown recently in rats that photothrombotic local brain injury that is induced by the intravenous injection of the photosensitive dye rose bengal and skull irradiation with a beam of focused light can trigger the expression of the protein p53 and initiate DNA damage in the area surrounding the thrombotic/necrotic core. We hypothesize that these changes are the signs of injury-induced apoptosis. We used pharmacological tools to characterize the injury-triggered DNA damage that we assayed by TUNEL-labeling, followed by a computer-assisted quantitative analysis. In addition, the morphology of apoptotic cells was visualized by fluorescent staining with propidium iodide. The pharmacological approach included: (a) the inhibition of endonucleases by intracerebroventricular injection of aurintricarboxylic acid (ATA, 20 micrograms/5 microliters); (b) the inhibition of protein synthesis by injecting cycloheximide subcutaneously (2.5 mg/kg); and (c) the blockade of glutamate receptors by injecting 2.5 mg/kg dizolcipine (MK-801) intravenously. These treatments significantly reduced the number of apoptotic cells that we counted in the area surrounding the necrotic core. The results show that injury-induced DNA damage involved de novo synthesis of proteins and an activation of endonucleases, suggesting the occurrence of apoptosis. In this model, apoptosis was associated with an activation of glutamate receptors. Treatments targeted at halting the apoptotic process might provide protection after stroke or after trauma to the brain.

False localization of rupture by computed tomography in bilateral internal carotid artery aneurysms

BACKGROUND

Focal clot on computed tomographic (CT) scan is one of the most reliable clues in determining the site of rupture in patients with multiple intracranial aneurysms. However, unusual presentation of clot may cause false localization of the ruptured aneurysm in bilateral aneurysms, particularly when they are located near the midline.

METHODS

We describe two cases of bilateral internal carotid artery (ICA) aneurysms presenting contralateral distribution of clot on CT scan.

RESULTS

Misjudgment of rupture site by the CT scan resulted in clipping of the wrong aneurysm in one patient. Disastrous rebleeding occurred before the second operation for the ruptured one. In the other patient, the rupture site was assumed correctly despite contralateral situation of clot on CT, and both aneurysms were treated in one operative session.

CONCLUSIONS

Adhesion and obliteration of the subarachnoid cisterns from previous hemorrhage will deviate the direction of hemorrhage and present contralateral clot on CT scan in bilateral aneurysms located near the midline as ICA aneurysms. Medial direction of rupture may obscure accurate localization of rupture side in such aneurysms.