Interdisciplinary Rendez-Vous Approach in Endovascular Stroke Treatment: A New Concept to Accelerate Mechanical Thrombectomy in Primary Stroke Centers

PURPOSE

Prompt endovascular treatment of patients with stroke due to intracranial Large Vessel Occlusion (LVO) is a major challenge in rural areas because neurointerventionalists are usually not available. As a result, treatment is delayed, and clinical outcomes are worse compared with patients primarily treated in comprehensive stroke centers (CSC). To address this problem, we present a concept in which interdisciplinary, on-site endovascular treatment is performed in a Primary Stroke Center (PSC) by a team of interventional neuroradiologists and cardiologists: the Rendez-Vous approach.

METHODS

Thirty-five patients with LVO who underwent interdisciplinary thrombectomy on-site at the PSC as part of the Rendez-Vous concept were compared with 72 patients who were transferred from a PSCs to the CSC for thrombectomy when diagnosed with LVO in terms of temporal sequences and clinical outcomes.

RESULTS

Patients treated on-site at the PSC as part of the Rendez-Vous approach were managed as successfully and without an increase in complication rates compared with patients treated secondarily at a CSC (91.7% successful interventions in Rendez-Vous vs. 87.3% in control group, p = 0.57). The time from diagnosis of LVO to groin puncture was reduced by mean 74.3 min with the Rendez-Vous concept (p < 0.01). Regarding the clinical outcome, a functionally independent status was achieved in 45.5% in the Rendez-Vous group and in 22.6% in the control group (p = 0.029).

CONCLUSION

Thanks to interdisciplinary teamwork between cardiology and interventional neuroradiology in local PSCs, times to successful reperfusion can be reduced. This has a potentially positive impact on the clinical outcome of stroke patients.

A new species of Anisophya (Orthoptera: Tettigoniidae: Phaneropterinae) from Argentina, its ultrasound male-female communication, life history and ecology

Anisophya arreguii sp. nov. is added as third species of the genus in Buenos Aires Province. A population living in humid meadows near La Plata, regularly observed during the last five years, was found to be different from A. punctinervis. It appears in two distinct annual generations. The male produces a continuous ultrasound calling song, to which the female responds with short signals after particular syllables. The verification of all Anisophya observations from Argentina on iNaturalist helped clarifying the distinctiveness of the new species. Some ecological aspects are briefly discussed, such as a vulnerable population in the city of La Plata.

Mikrischyrum musicum, a new katydid species from montane rainforest in southern Ecuador with complex pure-tone calling song (Orthoptera: Tettigoniidae: Pseudophyllinae: Platyphyllini)

The katydid Mikrischyrum musicum sp. nov. is described as third species of the genus, along with the remarkable low-ultrasound musical calling song of the male. It is the first species of the genus with known females, which are considerably larger than males and lack the conspicuous white spots on the pronotum. Pure-tone songs among pseudophyllines and development of pronotum markings of Platyphyllini are briefly discussed.

An interesting new record of the almost unknown brachypterous phaneropterine katydid Xenicola dohrni (Orthoptera: Tettigoniidae) from Argentina, and its high-ultrasound male-female communication

The southernmost record of the neotropical genus Xenicola is documented. An apparently tiny population of X. dohrni, a species described long ago from southern Brazil without other published records, lives at the shore of the Río de la Plata, 1000 km further south. Perhaps it has been established there by means of floating vegetation. The acoustic communication of this species is also very interesting: The male produces with its minuscule tegmina brief signals with a carrier frequency range between 80 and 100 kHz. The female responds, and the male modifies its song when engaged in a duet. It modifies it further, when the female responds from very close. The paper includes a review of the records of Xenicola species on biodiversity observation platforms.

Self-referencing circular dichroism ion yield measurements for improved statistics using femtosecond laser pulses

The combination of circular dichroism with laser mass spectrometry via the measurement of ion yields is a powerful tool in chiral recognition, but the measured anisotropies are generally weak. The method presented in this contribution reduces the measurement error significantly. A common path optical setup generates a pair of counter-rotating laser foci in the interaction region of a time-of-flight spectrometer. As the space focus condition is fulfilled for both foci individually, this becomes a twin-peak ion source with well separated and sufficiently resolved mass peaks. The individual control of polarization allows for in situ correction of experimental fluctuations measuring circular dichroism. Our robust optical setup produces reliable and reproducible results and is applicable for dispersion sensitive femtosecond laser pulses. In this contribution, we use 3-methyl-cyclopentanone as a prototype molecule to illustrate the evaluation procedure and the measurement principle.

Strong Differential Photoion Circular Dichroism in Strong-Field Ionization of Chiral Molecules

We investigate the differential ionization probability of chiral molecules in the strong-field regime as a function of the helicity of the incident light. To this end, we analyze the fourfold ionization of bromochlorofluoromethane (CHBrClF) with subsequent fragmentation into four charged fragments and different dissociation channels of the singly ionized methyloxirane. By resolving for the molecular orientation, we show that the photoion circular dichroism signal strength is increased by 2 orders of magnitude.

Studies in Neotropical Pseudophyllinae: A new genus of Cocconotini from the Colombian Andes and new subfamily assignment of the Dominican genus Anacaona (Tettigoniidae: Pseudophyllinae: Cocconotini)

Acuscercus eudaldoleondiazi n. gen et n. sp. from the Eastern slopes of the Colombian Andes is described, a typical long-winged member of the tribe Cocconotini, distinguished by peculiar morphology of male cerci. On the other hand, the Dominican genus Anacaona is moved from Cocconotini to the tribe Copiphorini (Conocephalinae). The status and tribal boundaries of Cocconotini and Eucocconotini are briefly discussed.

Clarifying the identity of the Uruguayan meadow katydid Conocephalus doryphorus (Orthoptera: Tettigoniidae: Conocephalini)

Conocephalus doryphorus (Karny, 1907), a member of the lesser meadow katydids, with around 150 recognized species in this genus with worldwide distribution, and around 25 of them living in South America, has been described from a unique immature female from an unknown locality in Uruguay.

Genetic Gains for Grain Yield in CIMMYT's Semi-Arid Wheat Yield Trials Grown in Suboptimal Environments

Wheat (Triticum aestivum L.) is a major staple food crop grown worldwide on >220 million ha. Climate change is regarded to have severe effect on wheat yields, and unpredictable drought stress is one of the most important factors. Breeding can significantly contribute to the mitigation of climate change effects on production by developing drought-tolerant wheat germplasm. The objective of our study was to determine the annual genetic gain for grain yield (GY) of the internationally distributed Semi-Arid Wheat Yield Trials, grown during 2002-2003 to 2013-2014 and developed by the Bread Wheat Breeding program at the CIMMYT. We analyzed data from 740 locations across 66 countries, which were classified in low-yielding (LYE) and medium-yielding (MYE) environments according to a cluster analysis. The rate of GY increase (GYC) was estimated relative to four drought-tolerant wheat lines used as constant checks. Our results estimate that the rate of GYC in LYE was 1.8% (38.13 kg ha-1 yr-1), whereas in MYE, it was 1.41% (57.71 kg ha-1 yr-1). The increase in GYC across environments was 1.6% (48.06 kg ha-1 yr-1). The pedigrees of the highest yielding lines through the coefficient of parentage analysis indicated the utilization of three primary sources-'Pastor', 'Baviacora 92', and synthetic hexaploid derivatives-to develop drought-tolerant, high and stably performing wheat lines. We conclude that CIMMYT's wheat breeding program continues to deliver adapted germplasm for suboptimal conditions of diverse wheat growing regions worldwide.

Trichoderma harzianum: Inhibition of mycotoxin producing fungi and toxin biosynthesis

A quarter of the world-wide crop is spoiled by filamentous fungi and their mycotoxins and weather extremes associated with the climate change lead to further deterioration of the situation. The ingestion of mycotoxins causes several health issues leading in the worst case to cancer in humans and animals. Common intervention strategies against mycotoxin producing fungi, such as the application of fungicides, may result in undesirable residues and in some cases to a stress induction of mycotoxin biosynthesis. Moreover, development of fungicide resistances has greatly impacted pre- and postharvest fungal diseases. Hence there is the need to develop alternative strategies to reduce fungal infestation and thus mycotoxin contamination in the food chain. Such a strategy for natural competition of important plant-pathogenic and mycotoxin producing fungi could be Trichoderma harzianum, a mycoparasitic fungus. Especially in direct comparison to certain tested fungicides, the inhibition of different tested fungal species by T. harzianum was comparable, more sustainable and in some cases more effective, too. Besides substantially reduced growth rates, a transcriptional based inhibition of mycotoxin biosynthesis in the competed Aspergillus species could be shown. Furthermore it could be clearly observed by high-resolution Scanning Electron Microscopy (SEM) that T. harzianum actively attaches to the competitor species followed by subsequent enzymatic lysis of those mycelial filaments. The analyzed isolate of T. harzianum MRI349 is not known to produce mycotoxins. In this study it could be successfully proven that T. harzianum as a biological competitor is an effective complement to the use of fungicides.

Meadow katydids (Orthoptera: Tettigoniidae: Conocephalini) from the Central-West Region of Brazil: Morphological, bioacoustic and cytogenetic study

Three species of Conocephalus and two of Euxiphidion from several localities of the Central-West Region of Brazil were studied. Conocephalus goianus Piza, 1977, C. saltator (Saussure, 1859) and C. versicolor (Redtenbacher, 1891) are recorded for the first time from Mato Grosso do Sul, one new species Euxiphidion veroni sp. nov. is described, and a new combination, Euxiphidion caizanum comb. nov. is proposed. The calling songs of C. saltator, C. versicolor, and E. veroni sp. nov. are described. All these three species call very continuously, also in the daytime. The three species of Conocepha-lus have mitotic metaphases with 2n♂ = 33 = 32 + X and 2n♀ = 34 = 32 + XX. Euxiphidion caizanum comb. nov. and    E. veroni sp. nov. have 2n♂ = 31 = 30 + X and 2n♀ = 32 = 30 + XX. Most of the autosomes of C. saltator and C. versicolor are meta/submetacentric, differing from C. goianus that has seven biarmed and nine monoarmed autosomes. Both Euxiphidion species present mostly telo/subtelocentric autosomes. The X chromosome is metacentric, and the largest element of the karyotype in the five species. No interstitial telomeric site (ITS) was observed in mitotic metaphases submitted to telomeric fluorescent in situ hybridization. Ecological aspects of the studied species are discussed.

Combined SPECT Imaging of Regional Cerebral Blood Flow (99mTc-HexamethylPropyleneamine Oxime, HMPAO) and Blood Volume (99mTc-RBC) to Assess Regional Cerebral Perfusion Reserve in Patients with Cerebrovascular Disease

In 53 patients with cerebrovascular disease (CVD), regional cerebral blood flow (CBF) and blood volume (CBV) were imaged by SPECT within one session. Slice division (CBF: CBV) yielded distribution of regional cerebral perfusion reserve (CPR). Semiquantitative evaluation was obtained from manually set ROIs by interhemispherical ratios (for CBF, CBV and CPR), using 2 SD from a normal group (n = 10) as a threshold. Sensitivities were 59% for CBF, 94% for CBV and 83% for CPR. Combined sensitivity was 98%. Establishing three constellations for CBF, CBV and CPR, regionally normal CBFs but quantitatively increased CBVs (+69%) and decreased CPRs (−31 %) were found in relatively early stages of CVD. Very advanced cases showed decreased CBFs (−65%), CBVs (−40%), CPRs (−49%) and a surrounding penumbra. In 87% (46/53 patients), such Theologically postulated constellations could be demonstrated. We conclude that combined CBF and CBV SPECT, assisted by CPR images, is a promising tool to detect CVD and to assess its individual regional severity.

[Characteristics of Nutrition in Competitive Sports, Ranging from Leisure Activities to High-Performance Athletics]

Nutrition has a crucial influence on physical and mental performance ability and is an important measure along sidetraining in high-performance athletes. However, this form of nutritionis not applicable for every athlete and in every situation. The question of optimal nutrition requires involvement with the particular type of sports, an athlete's current training stage, and athletes' individual requirements and objectives. Implementation takes time and individual motivation on the part of athletes and the specialist staff who engage intensively with the nutritional needs of athletes. In addition to adequate energy provision, it is important to divide the energy sensibly among the energy sources carbohydrates, fats, and protein. Performance athletes' higher need for protein can usually be covered in their regular diet; supplements are needed only in exceptional cases. Studies have shown that small amounts of 15 - 25 g protein are sensible after weight training, in order to stimulate muscle protein synthesis. The need for carbohydrates increases dynamically with the intensity and duration of physical exertion. A sufficient supply is crucial for achieving maximum performance. Low carb diets are unsuitable for performance athletes. So called low-glycogen training, however, can lead to better adjustment/adaptation processes in selected training stages and can increase performance ability.

Phlugis ocraceovittata and its ultrasonic calling song (Orthoptera, Tettigoniidae, Phlugidini)

Some observations on the small predatory katydid Phlugis ocraceovittata Piza 1960 from southern Brazil are presented. A male was calling both day and night, producing long uniformly structured sequences with maximum energy between 40 and 60 kHz. According to anecdotal and indirect evidence the species is not exclusively predacious and can live partly also on vegetable food.

Little walking leaves from southeast Ecuador: biology and taxonomy of Typophyllum species (Orthoptera, Tettigoniidae, Pterochrozinae)

Eight katydid species of the leaf-mimicking specialist genus Typophyllum were found in the southeast of Ecuador in an area comprising part of the eastern Andean cordillera and foothills toward the Cordillera del Cóndor in elevations between 850 and 3000 m. They are described along with the peculiar calling songs and other interesting aspects of their biology. Three of these species are new: T. morrisi sp. nov., T. onkiosternum sp. nov. and T. vignoni sp. nov. A fourth species represented by a single male is possibly new as well. In males and females of a species considered as identical with T. egregium Hebard 1924, which was previously known from a unique female specimen, was found a remarkable variation of coloration, in addition to the striking sexual dimorphism typical for the genus, with the females being twice as large as the small males. The latter is related to the curious mating behaviour, which is documented for this species and T. erosifolium Walker 1870. The two other species found in the region are T. bolivari Vignon 1925 and T. mortuifolium Walker 1870. The calling songs of four species were recorded. In T. erosifolium and T. morrisi sp. nov. the sounds are almost pure sine waves at the lower boundary of ultrasound. In T. egregium and T. onkiosternum sp. nov. the spectrum of the carrier frequency is broader, which might be related to lower and denser vegetation at higher elevation. Based on the intraspecific variety found in T. egregium and T. erosifolium, which includes variation in tegmina shape and venation pattern, are established several syonymies among Typophyllum species from western South America. T. erosifolium is found to be identical with T. peruvianum Pictet 1888 syn. nov. Additionally are considered identical T. inflatum Vignon 1925 and T. gibbosusm Vignon 1925 syn. nov., T. trigonum Vignon 1925 and T. quadriincisum Vignon 1925 syn. nov., and finally T. lacinipenne Enderlein 1917 and T. acutum Vignon 1925 syn. nov. and T. undulatum Caudell 1918 syn. nov. The discussion treats the problematic taxonomy of the little walking leaves, bioacoustics, the pre-copulatory riding behaviour, the sophisticated mimesis, and very briefly the uncertain position within the katydid phylogeny.

Reassessment and division of the genus Agraecia Audinet-Serville (Orthoptera: Tettigoniidae: Conocephalinae: Agraeciini)

Agraecia Audinet-Serville, the type-genus of Agraeciini, comprises fifteen species names: thirteen used for extant species, one junior synonym, and one fossil. The species are morphologically very dissimilar, and were collected and described from different localities of the world. The genus was reassessed based on recently collected specimens from Brazil and Argentina as well as museum specimens. Based on morphological characteristics we re-delimit Agraecia sensu novo, keeping only two of the previously assigned species: A. punctata Saint-Fargeau & Audinet-Serville and A. dorsalis Karny. The subtribe Agraeciina subtrib. nov. is defined, which include Agraecia s. nov. and three new genera (Iaratrox Chamorro-Rengifo & Lopes-Andrade gen. nov., Starkonsa Chamorro-Rengifo & Lopes-Andrade gen. nov., and Yvelinula Chamorro-Rengifo & Lopes-Andrade gen. nov.). Three additional genera treated here, Parasubria Karny, Ragoniella Chamorro-Rengifo & Lopes-Andrade gen. nov., Redtenbachus Chamorro-Rengifo & Lopes-Andrade gen. nov. and Sylvainhugiella Chamorro-Rengifo & Lopes-Andrade gen. nov. currently remain unclassified inside Agraeciini. We desig-nate a neotype and describe the female and male for A. punctata. Bertoniella Rehn is proposed as a junior synonym of Agraecia, and Parasubria ziczac Karny as syn. nov. of Parasubria vittipes (Redtenbacher) comb. nov. The fossil species is transferred to Senexefigia† Chamorro-Rengifo & Lopes-Andrade gen. nov. We also describe two new species of Iaratrox gen. nov., I. brasilienses Chamorro-Rengifo & Lopes-Andrade sp. nov. and I. longicornia Chamorro-Rengifo & Lopes-Andrade sp. nov. The holotype of Agraecia fallax Karny nomen dubium seems to be lost and the syntypes of Agraecia festae Griffini are currently unavailable for examination, therefore, these two species are treated as incertae sedis, and should probably be transferred. A key to the studied genera is provided, as well as a key to species of Agraecia s. nov. and Iaratrox gen. nov. The calling songs of Parasubria vittipes (Redtenbacher) comb. nov. and Ragoniella pulchella (Hebard) comb. nov. are described. Numerous morphological details and some natural history aspects are discussed.

On the family-group ranks of katydids (Orthoptera, Tettigoniidae)

The purpose of this note is to propose minor modifications to recent changes in the classification of katydids, to preserve the stability of the family Tettigoniidae as including all katydids. This concept has been used in the majority of references since it was established long ago (Krauss 1902), with comparatively few exceptions, where all katydid subfamilies were treated as families in superfamily Tettigonioidea.

The secret stridulatory file under the right tegmen in katydids (Orthoptera, Ensifera, Tettigonioidea)

Males of most species of crickets and katydids produce species-specific calling songs to attract conspecific females. The typical stridulatory apparatus of the Ensifera consists of a file-and-scraper system in the basal dorsal region of the forewings (tegmina): the file on the underside of the cubital vein of one tegmen is composed of a series of lamelliform teeth and is run against the sclerotized scraper at the edge of the other tegmen. The region directly distal of the cubital vein is often thin and glassy and serves to amplify and spread the sound. In stridulating crickets the tegmina are quite symmetrical with both the left and the right one containing a file, which is considered the ancestral condition (Béthoux 2012). Most of these crickets adopted a right-over-left wing overlap and use only the right file. The few extant species of the ancient group Hagloidea have bilaterally symmetrical tegmina, both with functional files, and individual males can change the overlap (Morris & Gwynne 1978). Katydids are distinguished by a left-over-right wing overlap, with a stridulatory file on the underside of the left tegmen, and a scraper on the right one, which usually is also equipped with a mirror as resonating structure.

Feasibility of balloon sinuplasty in patients with chronic rhinosinusitis: the Graz experience

BACKGROUND

Balloon sinuplasty (BSP) is a catheter-based technique to dilate sinus ostia and drainage pathways to create ventilation and drainage. The aim of this study was to evaluate the feasibility of BSP in routine treatment of patients suffering from chronic rhinosinusitis (CRS).

METHODOLOGY

Patients with CRS refractory to medical therapy who had been scheduled for endoscopic sinus surgery between 2009 and 2011 were included in this study.

RESULTS

Forty-five consecutive patients were included in this study, in whom 112 sinuses were approached by BSP. Of the 112 sinuses, 68 (60%) were planned as a "Balloon-Only" procedure and 44 (40%) were planned as a "Hybrid" procedure. Of the 68 sinuses in the "Balloon-Only" group, in 44 sinuses BSP failed, equating to a failure rate of 65%. Forty-four sinuses were planned for "Hybrid" procedures. In 29 of these sinuses BSP failed, giving a failure rate of 66%.

CONCLUSION

According to literature, BSP can be a useful adjunct technique to standard FESS. In our experience, however, a failure rate of 65% for "Balloon-Only" and of 66% for "Hybrid" procedures occurred, which was regarded as unacceptable by the study group. Therefore, the study initially scheduled for 200 consecutive patients, was abandoned.

Early microvascular dysfunction in cerebral small vessel disease is not detectable on 3.0 Tesla magnetic resonance imaging: a longitudinal study in spontaneously hypertensive stroke-prone rats

BACKGROUND

Human cerebral small vessel disease (CSVD) has distinct histopathologic and imaging findings in its advanced stages. In spontaneously hypertensive stroke-prone rats (SHRSP), a well-established animal model of CSVD, we recently demonstrated that cerebral microangiopathy is initiated by early microvascular dysfunction leading to the breakdown of the blood-brain barrier and an activated coagulatory state resulting in capillary and arteriolar erythrocyte accumulations (stases). In the present study, we investigated whether initial microvascular dysfunction and other stages of the pathologic CSVD cascade can be detected by serial magnetic resonance imaging (MRI).

FINDINGS

Fourteen SHRSP and three control (Wistar) rats (aged 26-44 weeks) were investigated biweekly by 3.0 Tesla (3 T) MRI. After perfusion, brains were stained with hematoxylin-eosin and histology was correlated with MRI data. Three SHRSP developed terminal CSVD stages including cortical, hippocampal, and striatal infarcts and macrohemorrhages, which could be detected consistently by MRI. Corresponding histology showed small vessel thromboses and increased numbers of small perivascular bleeds in the infarcted areas. However, 3 T MRI failed to visualize intravascular erythrocyte accumulations, even in those brain regions with the highest densities of affected vessels and the largest vessels affected by stases, as well as failing to detect small perivascular bleeds.

CONCLUSION

Serial MRI at a field strength of 3 T failed to detect the initial microvascular dysfunction and subsequent small perivascular bleeds in SHRSP; only terminal stages of cerebral microangiopathy were reliably detected. Further investigations at higher magnetic field strengths (7 T) using blood- and flow-sensitive sequences are currently underway.

NAC changes the course of cerebral small vessel disease in SHRSP and reveals new insights for the meaning of stases - a randomized controlled study

Background

N-Acetylcystein (NAC) reduces the reperfusion injury and infarct size in experimental macroangiopathic stroke. Here we now investigate the impact of NAC on the development of the histopathology of microangiopathic cerebrovascular disease including initial intravasal erythrocyte accumulations, blood–brain-barrier (BBB)-disturbances, microbleeds and infarcts.

Methods

Spontaneously Hypertensive Stroke-Prone Rats (SHRSP) were treated with NAC (12 mg/kg body weight, daily oral application for three to 30 weeks) and compared to untreated SHRSP. In all rats the number of microbleeds, thromboses, infarcts and stases were quantified by HE-staining. Exemplary brains were stained against von Willebrand factor (vWF), IgG, Glutathione and GFAP.

Results

NAC animals exhibited significant more microbleeds, a greater number of vessels with BBB-disturbances, but also an elevation of Glutathione-levels in astrocytes surrounding small vessels. NAC-treatment reduced the numbers of thromboses, infarcts and arteriolar stases.

Conclusions

NAC reduces the frequency of thromboses and infarcts to the expense of an increase of small microbleeds in a rat model of microangiopathic cerebrovascular disease. We suppose that NAC acts via an at least partial inactivation of vWF resulting in an insufficient sealing of initial endothelial injury leading to more small microbleeds. By elevating Glutathione-levels NAC most likely exerts a radical scavenger function and protects small vessels against extended ruptures and subsequent infarcts. Finally, it reveals that stases are mainly caused by endothelial injuries and restricted thromboses.

Blood brain barrier breakdown as the starting point of cerebral small vessel disease? - New insights from a rat model

Cerebral small vessel disease (CSVD, cerebral microangiopathy) leads to dementia and stroke-like symptoms. Lacunes, white matter lesions (WML) and microbleeds are the main pathological correlates depicted in in-vivo imaging diagnostics. Early studies described segmental arterial wall disorganizations of small penetrating cerebral arteries as the most pronounced underlying histopathology of lacunes. Luminal narrowing caused by arteriolosclerosis was supposed to result in hypoperfusion with WML and infarcts.We have used the model of spontaneously hypertensive stroke-prone rats (SHRSP) for a longitudinal study to elucidate early histological changes in small cerebral vessels. We suggest that endothelial injuries lead to multiple sites with blood brain barrier (BBB) leakage which cause an ongoing damage of the vessel wall and finally resulting in vessel ruptures and microbleeds. These microbleeds together with reactive small vessel occlusions induce overt cystic infarcts of the surrounding parenchyma. Thus, multiple endothelial leakage sites seem to be the starting point of cerebral microangiopathy. The vascular system reacts with an activated coagulatory state to these early endothelial injuries and by this induces the formation of stases, accumulations of erythrocytes, which represent the earliest detectable histological peculiarity of small vessel disease in SHRSP.In this review we focus on the meaning of the BBB breakdown in CSVD and finally discuss possible consequences for clinicians.

Cholesterol granulomas of the petrous apex; endonasal endoscopic approach

OBJECTIVE

Cholesterol granulomas are benign lesions that sometimes occur on the petrous apex (PA). We report our experience using an endoscopic endonasal approach to remove PA cholesterol granulomas.

MATERIAL AND METHODS

A retrospective patient chart analysis was conducted at a tertiary care university hospital.

RESULTS

Four patients (3 females, 1 male) were included in this study. Patients' ages ranged from 27 to 78 years. Computed tomography (CT) and magnetic resonance imaging (MRI) for diagnosis and computer-assisted navigation were performed. The most common symptom was abducens nerve palsy. The largest granuloma measured 5 x 2 cm and was located on the left side. An endoscopic endonasal approach was chosen and navigation was applied (3/4 patients) to identify the optimal area for opening the granuloma. No complications occurred, and patients were free from recurrence during the follow-up period.

CONCLUSION

The endoscopic endonasal approach to PA cholesterol granulomas is feasible and safe. Intra-operative navigation is recommended to identify the position of the internal carotid artery and determine the safest area for opening the granuloma without damaging the artery. Another advantage of this approach is an easier follow-up through diagnostic nasal endoscopy.

Do basophile structures as age dependent phenomenon indicate small vessel wall damage?

Here we demonstrate basophile structures located in the arteriolar wall and being associated with a plasma-protein-leakage. We assume, that the structures indicate blood-brain-barrier-disturbances and degenerative small vessel wall alterations.

Human induced pluripotent stem cells improve stroke outcome and reduce secondary degeneration in the recipient brain

Human induced pluripotent stem cells (hiPSCs) are a most appealing source for cell replacement therapy in acute brain lesions. We evaluated the potential of hiPSC therapy in stroke by transplanting hiPSC-derived neural progenitor cells (NPCs) into the postischemic striatum. Grafts received host tyrosine hydroxylase-positive afferents and contained developing interneurons and homotopic GABAergic medium spiny neurons that, with time, sent axons to the host substantia nigra. Grafting reversed stroke-induced somatosensory and motor deficits. Grafting also protected the host substantia nigra from the atrophy that follows disruption of reciprocal striatonigral connections. Graft innervation by tyrosine hydoxylase fibers, substantia nigra protection, and somatosensory functional recovery were early events, temporally dissociated from the slow maturation of GABAergic neurons in the grafts and innervation of substantia nigra. This suggests that grafted hiPSC-NPCs initially exert trophic effects on host brain structures, which precede integration and potential pathway reconstruction. We believe that transplantation of NPCs derived from hiPSCs can provide useful interventions to limit the functional consequences of stroke through both neuroprotective effects and reconstruction of impaired pathways.

Stases are associated with blood-brain barrier damage and a restricted activation of coagulation in SHRSP

Cerebral small vessel disease (CSVD) is a chronically proceeding pathology of small brain vessels associated with white matter lesions, lacunar infarcts, brain atrophy and microbleeds. CSVD leads to slowly increasing cognitive and functional deficits but may also cause stroke-like symptoms, if vessels in critical brain areas are affected. Spontaneously hypertensive stroke-prone rats (SHRSP) exhibit several vascular risk factors, develop infarcts and hemorrhages and therefore represent a relevant model for the study of CSVD. Using this animal model, we recently demonstrated that intravasal accumulations of erythrocytes, we interpreted as stases, stand at the beginning of a pathological vascular cascade. After stases microbleeds occur, which are followed by reactive microthromboses. Bleeds and thromboses finally cause hemorrhagic infarcts. Immunohistochemical stainings show, that plasma proteins like IgG are deposited in the walls of vessels affected by stases. Further, we found small clots and thread-shaped aggregations of thrombocytes as well as thread-shaped structures of von Willebrand-Factor within stases. Thus, we conclude that blood-brain barrier damages occur in the neighborhood of stases and stases seem to be associated with a restricted activation of blood coagulation without formation of obstructive thromboses. Finally, we demonstrate that small vessel damage rarely appears in the cerebellum. Even animals with multiple cerebral infarcts may be free of any cerebellar vascular pathology.

The pathologic cascade of cerebrovascular lesions in SHRSP: is erythrocyte accumulation an early phase?

Cerebral small vessel disease (CSVD) is associated with vessel wall changes, microbleeds, blood-brain barrier (BBB) disturbances, and reduced cerebral blood flow (CBF). As spontaneously hypertensive stroke-prone rats (SHRSP) may be a valid model of some aspects of human CSVD, we aimed to identify whether those changes occur in definite temporal stages and whether there is an initial phenomenon beyond those common vascular alterations. Groups of 51 SHRSP were examined simultaneously by histologic (Hematoxylin-Eosin, IgG-Immunohistochemistry, vessel diameter measurement) and imaging methods (Magnetic Resonance Imaging, 201-Thallium-Diethyldithiocarbamate/99m-Technetium-HMPAO Single Photon Emission Computed Tomography conducted as pilot study) at different stages of age. Vascular pathology in SHRSP proceeds in definite stages, whereas an age-dependent accumulation of erythrocytes in capillaries and arterioles represents the homogeneous initial step of the disease. Erythrocyte accumulations are followed by BBB disturbances and microbleeds, both also increasing with age. Microthromboses, tissue infarctions with CBF reduction, and disturbed potassium uptake represent the final stage of vascular pathology in SHRSP. Erythrocyte accumulations--we parsimoniously interpreted as stases--without cerebral tissue damage represent the first step of vascular pathology in SHRSP. If that initial phenomenon could be identified in patients, these erythrocyte accumulations might be a promising target for implementing prophylactic and therapeutic strategies in human CSVD.

Neuronal differentiation of human iPS-cells in a rat cortical primary culture

We tested the neuronal differentiation of human iPS-cells under in vitro conditions. For this purpose we pre-differentiated human (h) iPS-cells into neural stem cells and co-cultivated them with a cortical primary culture from embryonic rats. After 2 days of co-cultivation a certain number of hiPS-cells exhibited a clear neuronal morphology combined with expression of betaIII-tubulin and doublecortin. In addition, we found hiPS-cells without neuronal differentiation and cells already expressing betaIII-tubulin but not having yet distinctive axonal and dendritic processes. Human neuronal progenitors, starting neuronal differentiation, were contacted by both neuronal processes from rat neurons and oligodendrocytes, indicating a possible instructive influence by the primary culture on human cells. After 7 days of co-cultivation, however, we observed a complete degeneration of human iPS-derived cells and phagocytosis by microglial cells. Immunocytochemical stainings surprisingly revealed that microglial cells of the cortical primary culture express both CD8 and T-cell receptors.

Kidney pathology precedes and predicts the pathological cascade of cerebrovascular lesions in stroke prone rats

Introduction

Human cerebral small vessel disease (CSVD) has been hypothesized to be an age-dependent disease accompanied by similar vascular changes in other organs. SHRSP feature numerous vascular risk factors and may be a valid model of some aspects of human CSVD. Here we compare renal histopathological changes with the brain pathology of spontaneously hypertensive stroke-prone rats (SHRSP).

Material and Methods

We histologically investigated the brains and kidneys of 61 SHRSP at different stages of age (12 to 44 weeks). The brain pathology (aggregated erythrocytes in capillaries and arterioles, microbleeds, microthromboses) and the kidney pathology (aggregated erythrocytes within peritubular capillaries, tubular protein cylinders, glomerulosclerosis) were quantified separately. The prediction of the brain pathology by the kidney pathology was assessed by creating ROC-curves integrating the degree of kidney pathology and age of SHRSP.

Results

Both, brain and kidney pathology, show an age-dependency and proceed in definite stages whereas an aggregation of erythrocytes in capillaries and arterioles, we parsimoniously interpreted as stases, represent the initial finding in both organs. Thus, early renal tubulointerstitial damage characterized by rather few intravasal erythrocyte aggregations and tubular protein cylinders predicts the initial step of SHRSPs' cerebral vascular pathology marked by accumulated erythrocytes. The combined increase of intravasal erythrocyte aggregations and protein cylinders accompanied by glomerulosclerosis and thrombotic renal microangiopathy in kidneys of older SHRSP predicts the final stages of SHRSPs' cerebrovascular lesions marked by microbleeds and thrombotic infarcts.

Conclusion

Our results illustrate a close association between structural brain and kidney pathology and support the concept of small vessel disease to be an age-dependent systemic pathology. Further, an improved joined nephrologic and neurologic diagnostic may help to identify patients with CSVD at an early stage.

The influence of the heel effect in cone-beam computed tomography: artifacts in standard and novel geometries and their correction

For decades, the heel effect has been known to cause an angular dependence of the emitted spectrum of an x-ray tube. In radiography, artifacts were observed and attributed to the heel effect. However, no problems due to the heel effect were discerned in multi-slice computed tomography (MSCT) so far. With flat-detector CT (FDCT), involving larger cone angles and different system geometries, the heel effect might cause new artifacts. These artifacts were analyzed in this paper for system geometries different from the ones widely used nowadays. Simulations and measurements were performed. Simulations included symmetric as well as asymmetric detector layouts and different x-ray tube orientations with respect to the detector plane. The measurements were performed on a micro-CT system in an asymmetric detector layout. Furthermore, an analytical correction scheme is proposed to overcome heel effect artifacts. It was shown that the type of artifact greatly depends on the orientation of the x-ray tube and also on the type of detector alignment (i.e. symmetric or different types of asymmetric alignment). Certain combinations exhibited almost no significant artifact while others greatly influenced the quality of the reconstructed images. The proposed correction scheme showed good results that were further improved when also applying a scatter correction. When designing CT systems, care should be taken when placing the tube and the detector. Orientation of the x-ray tube like in most MSCT systems seems advisable in asymmetric detector layouts. However, a different type of tube orientation can be overcome with suitable correction schemes.