• Molecules and Cells
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• v.39 no.10
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• pp.768-775
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• 2016

The Arabidopsis female gametophyte contains seven cells with eight haploid nuclei buried within layers of sporophytic tissue. Following double fertilization, the egg and central cells of the gametophyte develop into the embryo and endosperm of the seed, respectively. The epigenetic status of the central cell has long presented an enigma due both to its inaccessibility, and the fascinating epigenome of the endosperm, thought to have been inherited from the central cell following activity of the DEMETER demethylase enzyme, prior to fertilization. Here, we present for the first time, a method to isolate pure populations of Arabidopsis central cell nuclei. Utilizing a protocol designed to isolate leaf mesophyll protoplasts, we systematically optimized each step in order to efficiently separate central cells from the female gametophyte. We use initial manual pistil dissection followed by the derivation of central cell protoplasts, during which process the central cell emerges from the micropylar pole of the embryo sac. Then, we use a modified version of the Isolation of Nuclei TAgged in specific Cell Types (INTACT) protocol to purify central cell nuclei, resulting in a purity of 75-90% and a yield sufficient to undertake downstream molecular analyses. We find that the process is highly dependent on the health of the original plant tissue used, and the efficiency of protoplasting solution infiltration into the gametophyte. By isolating pure central cell populations, we have enabled elucidation of the physiology of this rare cell type, which in the future will provide novel insights into Arabidopsis reproduction.

• Animal Systematics, Evolution and Diversity
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• v.18 no.1
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• pp.35-48
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• 2002

Larval development of Chirona cristatus Ren and Riu, 1978, found in the low part of rocks in the intertidal clone or the shell of scallops, was described in detail and compared with those of other known barnacles. Durations from nauplius through cyprid to pinhead stage are three weeks at 20$\pm$0.5$^{\circ}C$. Trilobed labrum bearing three groups of slender hairs and frontolateral horns folded under the anterior cephalic shield margin are diagnostic features through all nauplius stages. The posterior border of the cephalic shield bears a pair of cephalic shield spines in nauplius stages IV,V and Ⅵ. There is no specific hispid sets at the fourth group of the antennal endpodite. The dorsal thoracic spine, abdominal process and posterior shield spine haute numerous small spines Morphological features such as the cephalic shield, labrum, abdominal process, antennules, antennae and mandibles in all nauplius and cyprid stages are illustrated and described. The numerical setations of antennule in this species are found to be practically helpful for intraspecific identification of barnacle nauplius stages without dissection.

• Anatomy and Cell Biology
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• v.56 no.2
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• pp.200-204
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• 2023

Although in counterpart, the sphenopalatine artery (SPA), has been well described in the medical literature, the sphenopalatine vein (SPV) has received scant attention. Therefore, the present anatomical study was performed. Additionally, we discuss the variations, embryology, and clinical significance of the SPV. Adult cadaveric specimens underwent dissection of the SPV. In addition, some specimens were submitted for histological analysis of this structure. The SPV was found to drain from the sphenoidal sinus and nasal septum. Small tributaries traveled through the nasal septum with the posterior septal branches of the SPA and nasopalatine nerve. The SPA and SPV were found to travel through the sphenopalatine foramen and another tributary was found to perforate the medial plate of the pterygoid process and to connect to the pterygoid venous plexus which traveled lateral to the medial plate of the pterygoid process. The vein traveled through the posterior part of the lateral wall of the nasal cavity with the posterior lateral nasal branches of the SPA and the lateral superior posterior nasal branches of the maxillary nerve. To our knowledge, this is the first anatomical study on the SPV in humans. Data on the SPV provides an improved anatomical understanding of the vascular network of the nasal cavity. Developing a more complete picture of the nasal cavity and its venous supply might help surgeons and clinicians better manage clinical entities such as posterior epistaxis, cavernous sinus infections, and perform endoscopic surgery with fewer complications.

• Korean Journal of Clinical Laboratory Science
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• v.54 no.1
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• pp.61-67
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• 2022

Intraoperative neurophysiological monitoring (INM) ensures the stability and safety of specific surgeries in high-risk groups. As part of INM, intensive tests are conducted during the surgical process. When INM tests are applied during surgery, a delay in notifying the operating surgeon in cases of neurological defects can cause serious irreversible sequelae to the patient. Aortic replacement, which is necessitated due to aortic aneurysms and aortic dissection, is a complicated procedure that blocks the blood flow to the heart. When arteries that branch out from the aorta and supply blood to the spinal cord are replaced, blood flow to the spinal cord decreases, resulting in spinal ischemia. In aortic surgery, INM plays an important role in preventing spinal ischemia and serious complications by quickly detecting the early signs of spinal ischemia during cross-clamping and reporting it to the surgeon. Therefore, this paper was prepared to help examiners who conduct INM by detailing the process, method, time, and warning criteria for INM. This paper identifies the need for INM in aortic surgery and the process flow for a smooth test, accurate and rapid examination, and subsequent reporting.

• Journal of Korean Neurosurgical Society
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• v.51 no.5
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• pp.253-261
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• 2012

Objective : This study was performed to determine the anatomical landmarks and optimal dissection points of the facial nerve (FN) and the hypoglossal nerve (HGN) in the submandibular region to provide guidance for hypoglossal-facial nerve anastomosis (HFNA). Methods : Twenty-nine specimens were obtained from 15 formalin-fixed adult cadavers. Distances were measured based on the mastoid process tip (MPT), common carotid artery bifurcation (CCAB), and the digastric muscle posterior belly (DMPB). Results : The shortest distance from the MPT to the stylomastoid foramen was $14.1{\pm}2.9$ mm. The distance from the MPT to the FN origin was $8.6{\pm}2.8$ mm anteriorly and $5.9{\pm}2.8$ mm superiorly. The distance from the CCAB to the crossing point of the HGN and the internal carotid artery was $18.5{\pm}6.7$ mm, and that to the crossing point of the HGN and the external carotid artery was $15.1{\pm}5.7$ mm. The distance from the CCAB to the HGN bifurcation was $26.6{\pm}7.5$ mm. The distance from the digastric groove to the HGN, which was found under the DMPB, was about $35.8{\pm}5.7$ mm. The distance from the digastric groove to the HGN, which was found under the DMPB, corresponded to about 65.5% of the whole length of the DMPB. Conclusion : This study provides useful information regarding the morphometric anatomy of the submandibular region, and the presented morphological data on the nerves and surrounding structures will aid in understanding the anatomical structures more accurately to prevent complications of HFNA.

• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2719-2723
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• 2012

A kinetic study is reported for nucleophilic substitution reactions of benzyl 4-pyridyl carbonate 6 with a series of alicyclic secondary amines in MeCN. The plot of pseudo-first-order rate constant ($k_{obsd}$) vs. [amine] curves upward, which is typical for reactions reported previously to proceed through a stepwise mechanism with two intermediates (i.e., a zwitterionic tetrahedral intermediate $T^{\pm}$ and its deprotonated form $T^-$). Dissection of $k_{obsd}$ into the second- and third-order rate constants (i.e., $Kk_2$ and $Kk_3$, respectively) reveals that $Kk_3$ is significantly larger than $Kk_2$, indicating that the reactions proceed mainly through the deprotonation pathway (i.e., the $k_3$ process) in a high [amine] region. This contrasts to the recent report that the corresponding aminolysis of benzyl 2-pyridyl carbonate 5 proceeds through a forced concerted mechanism. An intramolecular H-bonding interaction was suggested to force the reactions of 5 to proceed through a concerted mechanism, since it could accelerate the rate of leaving-group expulsion (i.e., an increase in $k_2$). However, such H-bonding interaction, which could increase $k_2$, is structurally impossible for the reactions of 6. Thus, presence or absence of an intramolecular H-bonding interaction has been suggested to be responsible for the contrasting reaction mechanisms (i.e., a forced concerted mechanism for the reaction of 5 vs. a stepwise mechanism with $T^{\pm}$ and $T^-$ as intermediates for that of 6).

• Journal of Korean Neurosurgical Society
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• v.42 no.1
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• pp.35-41
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• 2007

Objective : Determining the location of paraclinoid aneurysms for microsurgery is important for selecting treatment options, especially when deciding on the release of the dural ring in direct clipping. We examined the reliability of using the optic strut as an anatomical landmark for evaluating the location of paraclinoid aneurysms. Methods : Cadaveric dissection was performed to establish the relationship of the optic strut to the dural ring. Results from these anatomic studies were compared with the three-demensional computed tomographic angiographic [3D-CTA] findings of nine patients with ten paraclinoid aneurysms between May 2004 and October 2005. These, 3D-CTA results were then compared with intraoperative findings. Results : The inferior boundary of the optic strut accurately localized the point at the proximal dural ring in cadaveric study. The optic strut and its relationship to the aneurysms was well observed on the multiplanar reformats of 3D-CTA. During microsurgery, nine of ten aneurysms were verified to arise from distal to the upper surface of the optic strut. Two aneurysms that had arisen between the inferior and superior boundary of the optic strut were observed to lie within the carotid cave. One aneurysm which had arisen at the inferior boundary of the optic strut and directed inferiorly was observed to lie within the cavernous sinus just after the release of the proximal ring. Conclusion : The optic strut, as identified with multiplanar reformats of 3D-CTA, provided a reliable anatomic landmark for the proximal rings and an important information about the location of aneurysms around the anterior clinoid process (ACP). Therefore, 3D-CTA and the optic strut could become an invaluable tool and a landmark in the assessment of the location of paraclinoid aneurysms for microsurgery.

• Archives of Reconstructive Microsurgery
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• v.1 no.1
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• pp.39-44
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• 1992

Benign peripheral nerve tumors, although infrequent, must be considered as a possible cause of pain and disability in the extremities. There are three varieties of these tumors that are of clinical importance: neurilemmomas, neurofibromas, and post-traumatic neuroma. Neurilemmomas are the most common primary solitary tumor of the peripheral nerve trunks, and are almost always benign, Neurofibromas may occur as a solitary nerve tumor, but can present as multiple lesions as in von Recklinghausen's disease. Clinically, this tumor may presents as a solitary mass in the subcutaneous tissue which is centrally located with the nerve fibers travelling through the tumor mass. Traumatic neuroma is the proliferation of nerve elements with connective tissue during the process of regeneration from severed nerves undergoing Wallerian degeration, and is therefore not a true neoplasm. A neuroma-in-countinuity is the result of partial severance of a nerve, or of a crushing or traction injury in which all or part of the epineurium and perineurium is intact. We experienced each of the three varieties. With magnification, the neurilemmoma was removed by meticulous dissection from the parent nerve preserving the normal fascicles to which it was attached. The neurofibroma was excised and the nerve was reconstructed with interposed vein graft and the neuroma-in-continuity was excised and reconstructed with sural nerve graft. We report histologic characteristics of each tumors and the methods to repair the nerve defects after tumor excision with brief discussion.

• Archives of Plastic Surgery
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• v.33 no.4
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• pp.510-513
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• 2006

Purpose: The Rectus abdominis muscle free flap is utilized in various reconstruction surgeries due to easiness in harvesting, consistency of vascular pedicle and reduced donor site morbidity. But rarely, femoral nerve injury during rectus abdominis harvesting can be resulted. We report a case of femoral nerve injury after rectus muscle harvesting and discuss the injury mechanism with the follow-up process of this injury. Methods: To reconstruct the defect of middle cranial base after wide excision of cystic adenocarcinoma of the external ear, rectus muscle free flap was havested in usual manner. To achieve a long vessel, inferior epigastric artery was dissected to the dividing portion of femoral artery and cut. Results: One week after the surgery, the patient noted sensory decrease in the lower leg, weakness in muscle strength, and disabilities in extension of the knee joint resulting in immobilization. EMG and NCV results showed no response on stimulation of the femoral nerve of the left leg, due to the defects in femoral nerve superior to the inguinal ligament. With routine neurologic evaluations and physical therapy, on the 75th day after the operation, the patient showed improvement in pain, sensation and muscle strength, and was able to move with walking frame. In 6 months after the operation, recovery of the muscle strength of the knee joint was observed with normal flexion and extension movements. Conclusion: Rarely, during dissection of the inferior epigastric artery, injuries to the femoral nerve can be resulted, probably due to excessive traction or pressure from the blade of the traction device. Therefore, femoral nerve injury can be prevented by avoiding excessive traction during surgery.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.2
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• pp.137-141
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• 2011

The extraction of an impacted third molar tooth is associated with many complications during the procedure and postoperative care. These complications include bleeding, swelling, pain, infection, as well as root fracture, proximal tooth injury, alveolar bone fracture, lingual nerve and inferior alveolar nerve injury etc. With the exception of a fractured root dislocation in the submandibular space, no direct submandibular gland injury related to extraction surgery has been reported until now. A 40 year old man visited the department of oromaxillofacial surgery at Yeouido St. Mary's Hospital for an extraction of the right mandible third molar. A partial third molar impaction was diagnosed by a clinical and radiographic examination. A surgical tooth extraction was practiced including buccal cortical bone osteotomy. During socket curettage, an encapsulated cyst-like lesion and a verified $3{\times}3\;cm$ neoplasm in the apically lingual direction were found during process of dissection. A biopsy confirmed that the neoplasm involved the submandibular gland and nerve trunk. This unusual anatomical organ injury during the surgical tooth extraction procedure is reported as a new complication during impacted third molar extraction.