Extensive intracranial arterial dolichoectasia involving distal branches of intracranial arteries: two cases report and review of the literature.

With the rapid development of noninvasive angiography techniques such as Magnetic Resonance Angiography (MRA) and Computer Tomography Angiography (CTA), more and more patients with intracranial arterial dolichoectasia (IADE) have been found, and clinical studies on this kind of vascular abnormity have become hot subjects in neurology. We presented two young patients with IADE extensively involving the branches of intracranial arteries, which were different from patients described in other articles. A young male patient was diagnosed with IADE after examination on admission, and further detailed examination revealed that the patient had osteropathia striata. Another young woman had an arterial malformation that mainly affected the distal branch of the intracranial artery. These two cases give us another perspective to look into IADE.

Mechanical thrombectomy using a Solitaire stent retriever in the treatment of pediatric acute ischemic stroke.

OBJECTIVE Mechanical thrombectomy using a Solitaire stent retriever has been widely applied as a safe and effective method in adult acute ischemic stroke (AIS). However, due to the lack of data, the safety and effectiveness of mechanical thrombectomy using a Solitaire stent in pediatric AIS has not yet been verified. The purpose of this study was to explore the safety and effectiveness of mechanical thrombectomy using a Solitaire stent retriever for pediatric AIS. METHODS Between January 2012 and December 2017, 7 cases of pediatric AIS were treated via mechanical thrombectomy using a Solitaire stent retriever. The clinical practice, imaging, and follow-up results were reviewed, and the data were summarized and analyzed. RESULTS The ages of the 7 patients ranged from 7 to 14 years with an average age of 11.1 years. The preoperative National Institutes of Health Stroke Scale (NIHSS) scores ranged from 9 to 22 with an average of 15.4 points. A Solitaire stent retriever was used in all patients, averaging 1.7 applications of thrombectomy and combined balloon dilation in 2 cases. Grade 3 on the modified Thrombolysis In Cerebral Infarction scale of recanalization was achieved in 5 cases and grade 2b in 2 cases. Six patients improved and 1 patient died after thrombectomy. The average NIHSS score of the 6 cases was 3.67 at discharge. The average modified Rankin Scale score was 1 at the 3-month follow-up. Subarachnoid hemorrhage after thrombectomy occurred in 1 case and that patient died 3 days postoperatively. CONCLUSIONS This study shows that mechanical thrombectomy using a Solitaire stent retriever has a high recanalization rate and excellent clinical prognosis in pediatric AIS. The safety of mechanical thrombectomy in pediatric AIS requires more clinical trials for confirmation. ABBREVIATIONS ACA = anterior cerebral artery; AIS = acute ischemic stroke; CTA = CT angiography; ICA = internal carotid artery; MCA = middle cerebral artery; mRS = modified Rankin Scale; mTICI = modified Thrombolysis In Cerebral Infarction; NIHSS = National Institutes of Health Stroke Scale; rt-PA = recombinant tissue plasminogen activator.

The origin of natural tetraploid loach Misgurnus anguillicaudatus (Teleostei: Cobitidae) inferred from meiotic chromosome configurations.

In the loach, or Oriental weatherfish Misgurnus anguillicaudatus (Teleostei: Cobitidae), diploid (2n = 50) and tetraploid individuals (4n = 100) are often sympatric in central China. The evolutionary mechanism of this tetraploidization was analyzed with the observation of meiotic behavior of chromosomes in both the germinal vesicles of mature oocytes and the primary spermatocytes in diploid and tetraploid loaches. Whereas diploid specimens usually showed 25 bivalents in meiotic cells, tetraploid loaches exhibited 0-6 quadrivalents and 38-50 bivalents in both sexes, with the modal number of quadrivalents as three in females and four in males. In the diploid specimens, the two largest metacentric chromosomes bearing nucleolar organizing regions (NORs) identified by chromomycin A(3) staining and fluorescence in situ hybridization with a 5.8S + 28S rDNA probe formed one bivalent with terminal association. In the tetraploids, four NOR-bearing chromosomes never formed a quadrivalent, but were organized into two terminally-associated bivalents. These findings suggest an autotetraploid origin of the natural tetraploid loach and subsequent rediploidization of whole genome. The latter process, however, seems still in progress as inferred from the concurrence of up-to several quadrivalents and the majority of bivalents.