1.Metabolite Chemical Composition of the Bletilla striata (Thunb.) Reichb. f. Endophyte Penicillium oxalicum
Ran LIU ; Xuehua HAN ; Jing GAO ; Min LUO ; Dale GUO ; Guangzhi WANG
Mycobiology 2023;51(3):148-156
Penicillium oxalicum strain can be isolated from the Bletilla striata (Thunb.) Reichb. f. tubers.Its solid-state fermentation products are concentrated by percolation extraction. Separation and purification have been conducted to the ethyl acetate extracts by preparative HPLC.Based on the use of spectrometry, we have determined 17 known compounds, 12,13-dihydroxy-fumitremorgin C (1), pseurotin A (2), tyrosol (3), cyclo-(L-Pro-L-Val) (4), cis-4-hydroxy-8-O-methylmellein (5), uracil (6), cyclo-(L-Pro-L-Ala) (7), 1,2,3,4-tetrahydro-4-hydroxy-4-quinolin carboxylic acid (8), cyclo-(Gly-L-Pro) (9), 2’-deoxyuridine (10), 1-(β-D-ribofuranosyl)thymine (11), cyclo-(L-Val-Gly) (12), 2’-deoxythymidine (13), cyclo-(Gly-D-Phe) (14), cyclo-L-(4-hydroxyprolinyl)-D-leucine (15), cyclo-(L)-4-hydroxy-Pro-(L)-Phe (16), uridine (17). Here, we report compounds 1–3, 5, 7–8, 11–12, 14–17 are first found and isolated from this endophyte.
2.Microvascular decompression of the posterior cerebral artery for treatment of oculomotor nerve palsy
I. Jonathan POMERANIEC ; Dale DING ; Alexander KSENDZOVSKY ; Kenneth C. LIU
Journal of Cerebrovascular and Endovascular Neurosurgery 2020;22(2):85-89
Oculomotor nerve palsy resulting from non-aneurysmal vascular compression is extremely rare. Microvascular decompression (MVD) has been previously shown to improve oculomotor nerve palsy (ONP) secondary to arterial compression. A 71-year-old female, with a history of Cushing’s disease previously treated with two transsphenoidal resections and Gamma Knife radiosurgery, presented with one year of progressive left eye diplopia and was diagnosed with a partial left oculomotor nerve palsy. We performed an orbitozygomatic craniotomy for MVD of the left posterior cerebral artery, which was found to be compressing the oculomotor nerve against the tentorium. Unfortunately, the patient’s partial ONP remained unchanged at one year follow-up. The present case suggests inconsistent outcomes of MVD for ONP. Patients with prior sellar or parasellar irradiation may be less likely to benefit from this treatment approach.
3.Bionic mechanical design and 3D printing of novel porous Ti6Al4V implants for biomedical applications.
Wen-Ming PENG ; Yun-Feng LIU ; Xian-Feng JIANG ; Xing-Tao DONG ; Janice JUN ; Dale A BAUR ; Jia-Jie XU ; Hui PAN ; Xu XU
Journal of Zhejiang University. Science. B 2019;20(8):647-659
In maxillofacial surgery, there is a significant need for the design and fabrication of porous scaffolds with customizable bionic structures and mechanical properties suitable for bone tissue engineering. In this paper, we characterize the porous Ti6Al4V implant, which is one of the most promising and attractive biomedical applications due to the similarity of its modulus to human bones. We describe the mechanical properties of this implant, which we suggest is capable of providing important biological functions for bone tissue regeneration. We characterize a novel bionic design and fabrication process for porous implants. A design concept of "reducing dimensions and designing layer by layer" was used to construct layered slice and rod-connected mesh structure (LSRCMS) implants. Porous LSRCMS implants with different parameters and porosities were fabricated by selective laser melting (SLM). Printed samples were evaluated by microstructure characterization, specific mechanical properties were analyzed by mechanical tests, and finite element analysis was used to digitally calculate the stress characteristics of the LSRCMS under loading forces. Our results show that the samples fabricated by SLM had good structure printing quality with reasonable pore sizes. The porosity, pore size, and strut thickness of manufactured samples ranged from (60.95± 0.27)% to (81.23±0.32)%, (480±28) to (685±31) μm, and (263±28) to (265±28) μm, respectively. The compression results show that the Young's modulus and the yield strength ranged from (2.23±0.03) to (6.36±0.06) GPa and (21.36±0.42) to (122.85±3.85) MPa, respectively. We also show that the Young's modulus and yield strength of the LSRCMS samples can be predicted by the Gibson-Ashby model. Further, we prove the structural stability of our novel design by finite element analysis. Our results illustrate that our novel SLM-fabricated porous Ti6Al4V scaffolds based on an LSRCMS are a promising material for bone implants, and are potentially applicable to the field of bone defect repair.
Alloys
;
Bionics
;
Bone Substitutes/chemistry*
;
Bone and Bones/pathology*
;
Compressive Strength
;
Elastic Modulus
;
Finite Element Analysis
;
Humans
;
Lasers
;
Materials Testing
;
Maxillofacial Prosthesis Implantation
;
Porosity
;
Pressure
;
Printing, Three-Dimensional
;
Prostheses and Implants
;
Prosthesis Design
;
Stress, Mechanical
;
Surgery, Oral/instrumentation*
;
Tissue Engineering/methods*
;
Titanium/chemistry*
4.A finite element analysis of the stress distribution to the mandible from impact forces with various orientations of third molars.
Yun-Feng LIU ; Russell WANG ; Dale A BAUR ; Xian-Feng JIANG
Journal of Zhejiang University. Science. B 2018;19(1):38-48
OBJECTIVE:
To investigate the stress distribution to the mandible, with and without impacted third molars (IM3s) at various orientations, resulting from a 2000-Newton impact force either from the anterior midline or from the body of the mandible.
MATERIALS AND METHODS:
A 3D mandibular virtual model from a healthy dentate patient was created and the mechanical properties of the mandible were categorized to 9 levels based on the Hounsfield unit measured from computed tomography (CT) images. Von Mises stress distributions to the mandibular angle and condylar areas from static impact forces (Load I-front blow and Load II left blow) were evaluated using finite element analysis (FEA). Six groups with IM3 were included: full horizontal bony, full vertical bony, full 450 mesioangular bony, partial horizontal bony, partial vertical, and partial 450 mesioangular bony impaction, and a baseline group with no third molars.
RESULTS:
Von Mises stresses in the condyle and angle areas were higher for partially than for fully impacted third molars under both loading conditions, with partial horizontal IM3 showing the highest fracture risk. Stresses were higher on the contralateral than on the ipsilateral side. Under Load II, the angle area had the highest stress for various orientations of IM3s. The condylar region had the highest stress when IM3s were absent.
CONCLUSIONS
High-impact forces are more likely to cause condylar rather than angular fracture when IM3s are missing. The risk of mandibular fracture is higher for partially than fully impacted third molars, with the angulation of impaction having little effect on facture risk.
Adult
;
Algorithms
;
Biomechanical Phenomena
;
Computer Simulation
;
Dental Stress Analysis
;
Elastic Modulus
;
Female
;
Finite Element Analysis
;
Humans
;
Imaging, Three-Dimensional
;
Mandible/physiopathology*
;
Mandibular Fractures/physiopathology*
;
Models, Biological
;
Molar, Third/physiopathology*
;
Stress, Mechanical
;
Tomography, X-Ray Computed
5.Surgical Approaches for Symptomatic Cerebral Cavernous Malformations of the Thalamus and Brainstem.
Dale DING ; Robert M STARKE ; R Webster CROWLEY ; Kenneth C LIU
Journal of Cerebrovascular and Endovascular Neurosurgery 2017;19(1):19-35
OBJECTIVE: Surgical resection of thalamic and brainstem cerebral cavernous malformations (CCMs) is associated with significant operative morbidity, but it may be outweighed, in some cases, by the neurological damage from recurrent hemorrhage in these eloquent areas. The goals of this retrospective cohort study are to describe the technical nuances of surgical approaches and determine the postoperative outcomes for CCMs of the thalamus and brainstem. MATERIALS AND METHODS: We reviewed an institutional database of patients harboring thalamic or brainstem CCMs, who underwent surgical resection from 2010 to 2014. The baseline and follow-up neuroimaging and clinical findings of each patient and the operative details of each case were evaluated. RESULTS: A total of eight patients, including two with thalamic and six with brainstem CCMs, were included in the study cohort. All patients had progressive neurological deterioration from recurrent CCM hemorrhage, and the median modified Rankin Scale (mRS) at presentation was 3. The median CCM maximum diameter and volume were 1.7 cm and 1.8 cm³, respectively. The thalamic CCMs were resected using the anterior transcallosal transchoroidal and supracerebellar infratentorial approaches each in one case (13%). The brainstem CCMs were resected using the retrosigmoid and suboccipital trans-cerebellomedullary fissure approaches each in three cases (38%). After a median follow-up of 11.5 months, all patients were neurologically stable or improved, with a median mRS of 2. The rate of functional independence (mRS 0-2) was 63%. CONCLUSION: Microneurosurgical techniques and approaches can be safely and effectively employed for the management of thalamic and brainstem CCMs in appropriately selected patients.
Brain Stem*
;
Cohort Studies
;
Follow-Up Studies
;
Hemangioma, Cavernous, Central Nervous System*
;
Hemorrhage
;
Humans
;
Intracranial Hemorrhages
;
Microsurgery
;
Neuroimaging
;
Retrospective Studies
;
Thalamus*
;
Vascular Malformations
6.Eyebrow Incision for Surgical Evacuation of a Lobar Intracerebral Hematoma with a Novel Endoport System.
Dale DING ; Colin J PRZYBYLOWSKI ; Robert M STARKE ; R Webster CROWLEY ; Kenneth C LIU
Journal of Cerebrovascular and Endovascular Neurosurgery 2017;19(2):101-105
Large lobar intracerebral hemorrhages (ICHs) can cause rapid neurological deterioration, and affected patients have low rates of survival and functional independence. Currently, the role of surgical intervention in the management patients with lobar ICHs is controversial. Minimally invasive technologies have been developed which may potentially decrease the operative morbidity of ICH surgery. The aim of this case report is to describe the technical aspects of the use of a novel minimally invasive endoport system, the BrainPath (NICO, Indianapolis, IN, USA), through an eyebrow incision for evacuation of a large lobar hematoma. An 84-year-old female presented with a left frontal ICH, measuring 7.5 cm in maximal diameter and 81 cm³ in volume, secondary to cerebral amyloid angiopathy. Through a left eyebrow incision, a miniature modified orbitozygomatic craniotomy was performed, which allowed endoport cannulation of the hematoma from a lateral subfrontal cortical entry point. Endoport-assisted hematoma evacuation resulted in nearly 90% volume reduction and improvement of the patient's functional status at clinical follow-up. We found that minimally invasive endoport technology can be employed in conjunction with conventional neurosurgical skull base principles to achieve safe and effective evacuation of large lobar hematomas in carefully selected patients.
Aged, 80 and over
;
Catheterization
;
Cerebral Amyloid Angiopathy
;
Cerebral Hemorrhage
;
Craniotomy
;
Eyebrows*
;
Female
;
Follow-Up Studies
;
Hematoma*
;
Humans
;
Intracranial Hemorrhages
;
Microsurgery
;
Skull Base
;
Stroke
7.Preoperative Embolization of Cerebral Arteriovenous Malformations with Silk Suture and Particles: Technical Considerations and Outcomes.
Jordan R CONGER ; Dale DING ; Daniel M RAPER ; Robert M STARKE ; Christopher R DURST ; Kenneth C LIU ; Mary E JENSEN ; Avery J EVANS
Journal of Cerebrovascular and Endovascular Neurosurgery 2016;18(2):90-99
OBJECTIVE: Embolization of cerebral arteriovenous malformations (AVMs) is commonly performed prior to surgical resection in order to reduce intraoperative bleeding and improve the safety of resection. Although most modern embolization procedures utilize permanent embolic agents, silk suture and polyvinyl alcohol (PVA) particles may offer unique advantages for preoperative devascularization. The aims of this retrospective cohort study are to describe the technical considerations and determine the outcomes for preoperative silk suture and PVA particle embolization (SPE) of AVMs. MATERIALS AND METHODS: We performed a retrospective review of our AVM embolization database. AVM patients who underwent preoperative SPE and subsequent surgical resection were included for analysis. Baseline patient demographics, AVM characteristics, embolization and operative records, and post-treatment outcomes were reviewed. RESULTS: A total of 11 patients who underwent 12 preoperative SPE procedures were included for analysis. Five AVMs were ruptured (45%), and the median nidus volume was 3.0 cm3 (range: 1.3-42.9 cm³). The Spetzler-Martin grade was I-II in seven patients (64%) and III-IV in four patients (36%). The degree of nidal obliteration was less than 25% in two procedures (17%), 25-50% in one procedure (8%), 50-75% in eight procedures (67%), and greater than 75% in one procedure (8%). The rates of post-embolization AVM hemorrhage and mortality were 8% and 0%, respectively. The postoperative angiographic obliteration rate was 100%, and the modified Rankin Scale score improved or stable in 91% of patients (median follow-up duration 2 months). CONCLUSION: Preoperative AVM SPE affords a reasonable risk to benefit profile for appropriately selected patients.
Cohort Studies
;
Demography
;
Endovascular Procedures
;
Follow-Up Studies
;
Hemorrhage
;
Humans
;
Intracranial Arteriovenous Malformations*
;
Intracranial Hemorrhages
;
Microsurgery
;
Mortality
;
Polyvinyl Alcohol
;
Retrospective Studies
;
Silk*
;
Stroke
;
Sutures*
;
Vascular Malformations
8.Preoperative Embolization of Cerebral Arteriovenous Malformations with Silk Suture and Particles: Technical Considerations and Outcomes.
Jordan R CONGER ; Dale DING ; Daniel M RAPER ; Robert M STARKE ; Christopher R DURST ; Kenneth C LIU ; Mary E JENSEN ; Avery J EVANS
Journal of Cerebrovascular and Endovascular Neurosurgery 2016;18(2):90-99
OBJECTIVE: Embolization of cerebral arteriovenous malformations (AVMs) is commonly performed prior to surgical resection in order to reduce intraoperative bleeding and improve the safety of resection. Although most modern embolization procedures utilize permanent embolic agents, silk suture and polyvinyl alcohol (PVA) particles may offer unique advantages for preoperative devascularization. The aims of this retrospective cohort study are to describe the technical considerations and determine the outcomes for preoperative silk suture and PVA particle embolization (SPE) of AVMs. MATERIALS AND METHODS: We performed a retrospective review of our AVM embolization database. AVM patients who underwent preoperative SPE and subsequent surgical resection were included for analysis. Baseline patient demographics, AVM characteristics, embolization and operative records, and post-treatment outcomes were reviewed. RESULTS: A total of 11 patients who underwent 12 preoperative SPE procedures were included for analysis. Five AVMs were ruptured (45%), and the median nidus volume was 3.0 cm3 (range: 1.3-42.9 cm³). The Spetzler-Martin grade was I-II in seven patients (64%) and III-IV in four patients (36%). The degree of nidal obliteration was less than 25% in two procedures (17%), 25-50% in one procedure (8%), 50-75% in eight procedures (67%), and greater than 75% in one procedure (8%). The rates of post-embolization AVM hemorrhage and mortality were 8% and 0%, respectively. The postoperative angiographic obliteration rate was 100%, and the modified Rankin Scale score improved or stable in 91% of patients (median follow-up duration 2 months). CONCLUSION: Preoperative AVM SPE affords a reasonable risk to benefit profile for appropriately selected patients.
Cohort Studies
;
Demography
;
Endovascular Procedures
;
Follow-Up Studies
;
Hemorrhage
;
Humans
;
Intracranial Arteriovenous Malformations*
;
Intracranial Hemorrhages
;
Microsurgery
;
Mortality
;
Polyvinyl Alcohol
;
Retrospective Studies
;
Silk*
;
Stroke
;
Sutures*
;
Vascular Malformations
9.Microsurgical Strategies Following Failed Endovascular Treatment with the Pipeline Embolization Device: Case of a Giant Posterior Cerebral Artery Aneurysm.
Dale DING ; Robert M STARKE ; Kenneth C LIU
Journal of Cerebrovascular and Endovascular Neurosurgery 2014;16(1):26-31
Treatment of giant posterior circulation aneurysms, via endovascular or microsurgical approaches, carries a high risk of morbidity and mortality. While flow-diverting stents (FDSs) represent a potent therapy for endovascular reconstruction of complex aneurysms, they are also associated with novel complications for which effective salvage techniques are lacking. We present a unique complication from failed treatment with a FDS. A 51 year-old male presented with increasing headaches secondary to a giant, fusiform aneurysm of the left posterior cerebral artery, which was largely thrombosed. Due to progressive enlargement of the aneurysm corresponding to worsening clinical symptoms, the lesion was treated with two Pipeline embolization devices (ev3, Plymouth, MN, United States). Three months after Pipeline embolization device treatment, complete posterior cerebral artery occlusion was observed at the origin of the proximal stent. Despite the lack of arterial inflow, the aneurysm dome continued to grow, resulting in obstructive hydrocephalus. Therefore microsurgical intervention was undertaken to trap and excise the aneurysm. The patient's postoperative course was complicated by multiple venous infarcts, ultimately resulting in death. Successful microsurgical obliteration of aneurysms previously treated with FDSs is extremely difficult. A combination of judicious preoperative planning and meticulous intraoperative surgical technique are requisite for effective management of these complicated cases.
Aneurysm
;
Endovascular Procedures
;
Headache
;
Humans
;
Hydrocephalus
;
Intracranial Aneurysm*
;
Male
;
Microsurgery
;
Middle Aged
;
Mortality
;
Posterior Cerebral Artery*
;
Stents
;
Stroke
10.Balloon Anchor Technique for Pipeline Embolization Device Deployment Across the Neck of a Giant Intracranial Aneurysm.
Dale DING ; Robert M STARKE ; Avery J EVANS ; Mary E JENSEN ; Kenneth C LIU
Journal of Cerebrovascular and Endovascular Neurosurgery 2014;16(2):125-130
Treatment of giant intracranial aneurysms, via either surgical or endovascular approaches, is associated with a high level of technical difficulty as well as a high rate of treatment-related morbidity and mortality. Flow-diverting stents, such as the Pipeline embolization device (PED), have drastically altered the therapeutic strategies for the treatment of giant aneurysms. Gaining endovascular access using a microcatheter to the portion of the parent artery distal to the aneurysm neck is requisite for safe and effective stent deployment. Giant aneurysms are often associated with vascular tortuosity, which necessitates significant catheter support systems to enable maneuvering of PEDs across the aneurysm neck. This is also required in order to reduce the probability of stent herniation within giant aneurysms. We report on a case of a giant supraclinoid internal carotid artery (ICA) aneurysm which was treated successfully with a PED utilizing a balloon anchor technique to facilitate direct microcatheter access across the aneurysm neck.
Aneurysm
;
Arteries
;
Carotid Artery, Internal
;
Catheters
;
Endovascular Procedures
;
Humans
;
Intracranial Aneurysm*
;
Mortality
;
Neck*
;
Parents
;
Stents
;
Stroke
;
Subarachnoid Hemorrhage

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