Surgery for amygdala enlargement with mesial temporal lobe epilepsy: pathological findings and seizure outcome

OBJECTIVE

Amygdala enlargement (AE) has been suggested to be a subtype of mesial temporal lobe epilepsy (MTLE). However, most reports related to AE have referred to imaging studies, and there have been few reports regarding surgical and pathological findings. The present study was performed to clarify the surgical outcomes and pathology of AE.

METHODS

Eighty patients with drug-resistant MTLE were treated surgically at the Tokyo Metropolitan Neurological Hospital between April 2010 and July 2013. Of these patients, 11 were diagnosed as AE based on presurgical MRI. Nine patients with AE underwent selective amygdalohippocampectomy, while the remaining two patients underwent selective amygdalotomy with hippocampal transection. Intraoperative EEG was routinely performed. The histopathology of the resected amygdala tissue was evaluated and compared with the amygdala tissue of patients with hippocampal sclerosis.

RESULTS

Pathological findings indicated that 10 of 11 specimens had closely clustering hypertrophic neurons with vacuolisation of the background matrix. Slight gliosis was seen in nine specimens, while the remaining two showed no gliotic changes. Intraoperative EEG showed abnormal sharp waves that seemed to originate not from the amygdala but from the hippocampus in all cases. Ten patients became seizure-free during the postoperative follow-up period.

CONCLUSIONS

Histopathologically, clustering hypertrophic neurons and vacuolation with slight gliosis or without gliosis were considered to be pathological characteristics of AE. Amygdalohippocampectomy or hippocampal transection with amygdalotomy is effective for seizure control in patients with AE.

[Two cases of cerebral infarction due to focal irradiation for glioma in adults]

Radiation-induced vasculopathy is a complication of radiation therapy. Most reports regarding post-irradiation ischemic stroke with intracranial tumors are restricted to pediatric cases. Here we report two adult cases of delayed brain infarction due to anterior and middle cerebral artery stenosis or occlusion seemingly caused by focal radiation therapy for malignant glioma. Although radiation-induced ischemic stroke in adults is relatively uncommon, it is possible that the morbidity rate of radiation-induced stroke in malignant glioma patients will increase with prolonged survival due to advances in therapy. Therefore, regular evaluation of intracranial vasculature following radiation therapy is necessary.

Effectiveness of zigzag Incision and 1.5-Layer method for frontotemporal craniotomy

Background:

In this era of minimally invasive treatment, it is important to make operative scars as inconspicuous as possible, and there is a great deal of room for improvement in daily practice. Zigzag incision with coronal incision has been described mainly in the field of plastic surgery, and its applicability for skin incision in general neurosurgery has not been reported.

Methods:

Zigzag incision with 1.5-layer method was applied to 14 patients with unruptured cerebral aneurysm between April 2011 and August 2012. A questionnaire survey was administered among patients with unruptured aneurysm using SF-36v2 since April 2010. The results were compared between patients with zigzag incision and a previous cohort with traditional incision.

Results:

There were no cases of complications associated with the operative wound. In the questionnaire survey, all parameters tended to be better in the patients with zigzag incision, and role social component score (RCS) was significantly higher in the zigzag group than in the traditional incision group (P =0.0436).

Conclusion:

Zigzag incision using the 1.5-layer method with frontotemporal craniotomy seems to represent an improvement over the conventional curvilinear incision with regard to cosmetic outcome and RCS.

A surgical case of frontal lobe epilepsy due to focal cortical dysplasia accompanied by olfactory nerve enlargement: case report

A 45-year-old man came to our clinic due to refractory general tonic seizure and an attack of unintended yelling. Magnetic resonance imaging (MRI) demonstrated mild cortical hyperintensity on fluid attenuated inversion recovery (FLAIR) image in the left basal frontal area. Enlargement of the left olfactory nerve was also detected below the affected gyrus. Subtotal resection of the MRI-visible epileptogenic lesion was performed without any neurological deficit. The final pathological diagnosis was focal cortical dysplasia (FCD) type IIa. Seizures and yelling attacks subsided after surgery. Extracerebral abnormalities, including cranial nerve enlargement, are common in patients with hemimegalencephaly. However, such abnormalities are rare with FCD.

Emerging sylvian subpial hematoma after the repair of the ruptured anterior cerebral artery aneurysm with interhemispheric approach: case report

A 60-year-old woman was admitted to the hospital due to a sudden loss of consciousness. Computed tomography (CT) revealed a thick subarachnoid hemorrhage in almost all of the parachiasmatic cisterns, including the sylvian cisterns, with mild hydrocephalus. Three dimensional (3D)-CT angiography showed an irregularly shaped aneurysm at the bifurcation of the left A2 and the frontopolar artery. The aneurysm was successfully obliterated by clipping through the interhemispheric approach. CT performed immediately after the operation showed a newly formed left temporal subpial hematoma. The patient's neurological status improved gradually after surgery, but deteriorated again 2 days after the operation. CT revealed an enlarging right sylviansubpial hematoma. The subpial hematoma was rapidly removed surgically. Slight hemiparesis and impaired higher cognitive function remained after a shunt procedure for subsequent hydrocephalus. Emerging sylvian hematoma associated with a distant site of a ruptured aneurysm is extremely rare. However, adequate attention is required in cases with a thick subarachnoid hemorrhage in distant fissures.

Transsylvian hippocampal transection for mesial temporal lobe epilepsy: surgical indications, procedure, and postoperative seizure and memory outcomes

Object

Amygdalohippocampectomy is a well-established, standard surgery for medically intractable mesial temporal lobe epilepsy (MTLE). However, in the case of MTLE without hippocampal atrophy or sclerosis, amygdalohippocampectomy is associated with decreased postoperative memory function. Hippocampal transection (HT) has been developed to overcome this problem. In HT the hippocampus is not removed; rather, the longitudinal hippocampal circuits of epileptic activities are disrupted by transection of the pyramidal layer of the hippocampus. The present study describes a less invasive modification of HT (transsylvian HT) and presents the seizure and memory outcomes for this procedure.

Methods

Thirty-seven patients with MTLE (18 men and 19 women; age range 9–63 years; 19 with surgery on the right side and 18 with surgery on the left side; seizure onset from 3 to 34 years) who were treated with transsylvian HT were retrospectively analyzed. All patients had left-side language dominance, and follow-up periods ranged from 12 to 94 months (median 49 months). Seizure outcomes were evaluated for all patients by using the Engel classification. Memory function was evaluated for 22 patients based on 3 indices (verbal memory, nonverbal memory, and delayed recall), with those scores obtained using the Wechsler Memory Scale–Revised. Patients underwent evaluation of the memory function before and after surgery (6 months–1 year).

Results

Engel Class I (completely seizure free) was achieved in 25 patients (67.6%). Class II and Class III designation was achieved in 10 (27%) and 2 patients (5.4%), respectively. There were differences in memory outcome between the sides of operation. On the right side, verbal memory significantly increased postoperatively (p = 0.003) but nonverbal memory and delayed recall showed no significant change after the operation (p = 0.718 and p = 0.210, respectively). On the left side, all 3 indices (verbal memory, nonverbal memory, and delayed recall) showed no significant change (p = 0.331, p = 0.458, and p = 0.366, respectively).

Conclusions

Favorable seizure outcome and preservation of verbal memory were achieved with transsylvian HT for the treatment of MTLE without hippocampal atrophy or sclerosis.

Nonspecies-specific effects of mouse oviducts on the development of bovine IVM/IVF embryos by a serum free co-culture

In Experiment 1, development of bovine embryos derived from in vitro-matured (IVM) and in vitro-fertilized (IVF) oocytes was examined under 4 culture conditions: 1) co-culture with mouse ampullae continuously for 8 d, 2) co-culture with mouse ampullae that were replaced with fresh ampullae at 48-h intervals, 3) co-culture with bovine granulosa cell monolayers, and 4) culture in medium alone. Culture medium consisted of tissue culture medium 199 (TCM-199) supplemented with 1% fetal calf serum (FCS). Inseminated oocytes were transferred to each of the culture treatment 24 h after insemination and were cultured for 8 d. The number of blastocysts per number of cleaved ova obtained after co-culture with mouse ampullae (42.9%) was significantly (P<0.05) higher than that obtained after co-culture with granulosa cell monolayers (28.3%) or culture without cells (4.2%). In Experiment 2, the developmental ability of bovine IVM/IVF embryos co-cultured with mouse ampullae supplemented with or without serum was examined. When serum was excluded from the culture medium, 26.4% (33 125 ) of the total number of embryos cultured were able to develop to the blastocysts stage using this co-culture system. This value was comparable to that obtained in a serum-supplemented co-culture system (30.7%; 39 125 ). In addition, the developmental ability of embryos that reached to the 4-cell stage or beyond at 46 to 48 h after insemination was not significantly different when the embryos were co-cultured with mouse ampullae with (38.5 vs 44.6%) or without (37.0 vs 33.8%) serum.

Impact of screening with thyroid ultrasonography in myasthenia gravis patients

OBJECTIVES

This study was conducted to screen thyroid abnormality evaluated with ultrasonography (US) in patients with myasthenia gravis (MG) and investigate further when malignancy is suspected.

METHODS

Thyroid screening using US was conducted in 162 patients with MG. In cases where malignancy was suspected, further investigations were performed.

RESULTS

Abnormal US findings were detected in 125 of 162 patients with MG (72 patients with nodules, 74 patients with cysts, 27 patients with diffuse findings such as enlargement, atrophy, a hypoechoic pattern or a heterogenous echoic pattern, and 28 patients with calcification). From among these 125 subjects, 30 patients underwent further examinations such as needle aspiration cytology. As a result, six patients (3.7% of 162 cases) were positive for papillary carcinoma. The size of the carcinoma in three patients was <10 mm, yet the stage of thyroid carcinomas was high (stage III or IVa) in all six cases.

CONCLUSIONS

Our data suggest that the prevalence of thyroid carcinoma in cases of MG may be higher than that of the general population. Furthermore, in patients with MG, there is a possibility that the stage of the carcinoma is higher even when the carcinoma is of a very small size. Patients with MG, when diagnosed, should be advised to undergo US screening of the thyroid because most cases of thyroid carcinoma are highly curable.

10 TRACEABILITY SYSTEM FOR AN INDIVIDUAL FROZEN SEMEN STRAW BY A TINY RADIO FREQUENCY IDENTIFICATION CHIP

A traceability of frozen semen straws that certify the bloodline of a sire will improve the efficiency of cattle breeding. Semen of the sire can be generally identified by the colour of a straw and printing on a straw. However, it is difficult to identify individual frozen semen straws by the conventional method. To identify straws individually, each straw must be tagged with a unique ID that is able to be read quickly in the frozen state. We have established the identification method for individual frozen semen straws using radio frequency identification (RFID) and developed a traceability system that is able to record the distribution history of an individual semen straw from the production of frozen semen to artificial insemination (AI). We used a 2.5-mm diameter straw combined with an RFID tag, which consisted of a tiny RFID chip (μ-Chip: Hitachi Co. Ltd, 0.4 × 0.4 × 0.2 mm) and a thin aluminum antenna on the polyester sheet (54 × 1.5 × 0.05 mm). The μ-chip contains a unique ID (128 bit). It responds to the 2.45 GHz microwave frequency that is emitted from the RFID reader and transmits its ID to the RFID reader. The μ-Chip retains its function on a straw, which has been stored in the liquid nitrogen (–196°C). Artificial insemination of the frozen semen straw with the RFID tag could be performed using a conventional AI gun. The semen traceability system consisted of the database server and the client software. Information about semen straws is connected with their ID and stored on the database server. Producers and distributors of frozen semen can count the number of semen straws correctly by reading their ID one by one and can send information to the database server through the web by easy operation using the client software. Artificial insemination information can be instantly recorded by the handy terminal that is able to read both a bar-code on the ear tag of the cow and the RFID tag of the straw. The system has been used on fields at Gifu Prefecture in Japan for ∼3 months. Eight hundred thirty-one frozen semen straws with the RFID tag were produced from 3 bulls. After freezing of the straws, 17 straws were not identified with their ID. It was speculated that their μ-Chips were disconnected from the antenna during freezing. Six hundred ninety-four straws were distributed to the 7 AI centers. Five hundred thirty straws were used for AI by 15 inseminators to a total of 424 cows at the 101 farms. Although only one straw could not read its ID after AI, information of the remaining 529 straws were recorded on the database accurately. A strict traceability of frozen semen straws can be established using the individual identification of straws by RFID. Information stored in the database would be useful for the evaluation of sire and the reproductive management of cows. This work was supported by a grant from the Ministry of Agriculture, Forestry and Fisheries of Japan (MAFF).

Rational Construction of Polymeric Nonlinear Optical Materials. Properties of Chromophore-Functionalized Polystyrenes

Processable polymeric nonlinear optical materials can be synthesized by functionalizing a glassy macromolecule with chromophores having large quadratic hyperpolarizabilities, followed by poling in an electric field. In the present case, the functionalization of polystyrene with 4- (4-nitrophenylaza)(N-ethyl)(2-hydroxyethyl))aniline, 4-(4-N,N-dimethylaminostyryl) pyridine, and N-(4-nitrophenyl)-L-prolinol is described. Particularly noteworthy is the high level of chromophore units that can be incorporated into transparent films of these materials, the high second harmonic coefficients that can be achieved (as high as d33 – 11 × 10-9 esu at 1064 nm), and the long-term temporal stability of the second harmonic generation capacity.

Statistical properties of spectral fluctuations for a quantum system with infinitely many components

Extending the idea formulated in Makino [Phys. Rev. E 67, 066205 (2003)], that is based on the Berry-Robnik approach [M. V. Berry and M. Robnik, J. Phys. A 17, 2413 (1984)], we investigate the statistical properties of a two-point spectral correlation for a classically integrable quantum system. The eigenenergy sequence of this system is regarded as a superposition of infinitely many independent components in the semiclassical limit. We derive the level number variance (LNV) in the limit of infinitely many components and discuss its deviations from Poisson statistics. The slope of the limiting LNV is found to be larger than that of Poisson statistics when the individual components have a certain accumulation. This property agrees with the result from the semiclassical periodic-orbit theory that is applied to a system with degenerate torus actions [D. Biswas, M. Azam, and S. V. Lawande, Phys. Rev. A 43, 5694 (1991)].

72 PRESERVATION OF PORCINE GONOCYTES AT 4°C AND IN LIQUID NITROGEN - A PRESERVATION MODEL OF GENETIC RESOURCES IN DOMESTIC ANIMALS AND IN ENDANGERED SPECIES

Gonocytes are primitive germ cells that reside in neonatal testis and are believed to be progenitor-type stem cells that differentiate into spermatogonial stem cells. Because of their self-renewal ability, gonocytes may be one of the targets for cryopreservation of genetic resources in domestic animals and in endangered species. However, there are only a few reports regarding the preservation of gonocytes and spermatogonial stem cells isolated from the testis. In this experiment, porcine gonocytes were used as a model for preservation of genetic resources. Porcine testes were collected at 2–6 days after birth. They were divided into the 5 experimental groups for storage: (1) DMEM/F12 medium, (2) DMEM/F12 + 15 mm HEPES, (3) PBS, (4) PBS + 15 mm HEPES, and (5) Liquid-Free, and stored at 4�C for 24 h. The testes were minced by scissors and digested with 2-step enzyme treatments. The gonocytes were isolated by Percoll density gradients and recovered from the fraction between 50 and 60%. The viability of cells was assessed using trypan blue dye exclusion. To determine optimum cryopreservation conditions for gonocytes, 10% DMSO, 10% glycerol, and 0.07 mm sucrose were used as cryoprotectants. The isolated gonocytes were suspended in DMEM/F12 + 10% FBS containing cryoprotectant at 4�C, kept at –80�C overnight, and finally immersed in liquid nitrogen. After freezing and thawing of gonocytes, cells were examined for viability and then cultured in DMEM/F12 + 10% FBS in 5% CO2, 95% air at 37�C in humidified atmosphere. Identification of gonocytes was performed using a specific marker of gonocytes, a lectin Dolichos biflorus agglutinin (DBA; Goel et al. 2007 Biol. Reprod. 77, 127–137). The gonocytes were recovered from testes at the purity level of around 70%. Cell viability in average after storage of testes at 4�C was significantly higher in DMEM/F12 + HEPES (95.3%) and PBS + HEPES (89.8%) than in DMEM/F12 (73.9%), PBS (79.7%), and Liquid-Free (72.2%) (P < 0.05; ANOVA). The addition of HEPES in storage medium seemed to be effective for improving cell viability. The use of 10% DMSO and 0.07 mm sucrose as cryoprotectants supported high cell viability (74.4%) of gonocytes after freezing and thawing. The addition of glycerol had an adverse effect on cell viability after freezing (18.3%). When cells were cultured, gonocytes started to form colonies after 3 days and continued to proliferate for at least 7 days in culture. These colonies showed DBA affinity and maintained their nature as gonocytes. The viability of gonocytes can be maintained in the testis at 4�C for at least 24 h and after freezing and thawing. The stored gonocytes successfully proliferated in culture for at least 7 days. In conclusion, these results may provide useful information for short-term storage of primitive germ cells and preservation of genetic resources in domestic animals and in endangered species. It may also have implications for assisted reproductive technology in humans.

A unique case of limb-girdle muscular dystrophy type 2A carrying novel compound heterozygous mutations in the human CAPN3 gene

A unique sib pair afflicted by limb girdle muscular dystrophy type 2A (LGMD2A) is described showing a slowly progressive autosomal recessive type of muscular dystrophy with onset in the third and fourth decades. The patients had early asymmetric muscle involvement characterized by prominent biceps brachii atrophy with sparing of the knee extensors. Additional findings included elevation of serum creatine kinase level, myopathic EMG changes and dystrophic type of pathology on muscle biopsy. Asymmetrical wasting of muscles in the extremities exhibited uniform and highly selective CT imaging patterns. RNA and DNA analyses confirmed novel compound heterozygous mutations (R147X/L212F) in the human CAPN3 gene.

Evaluation of acrosomal status of bovine spermatozoa using concanavalin a lectin

We report here that fluorescein isothiocyanate-conjugated concanavalin A (FITC-ConA) specifically labels the acrosomal region of acrosome-reacted bovine spermatozoa. This labeling is found to be useful in evaluating the acrosome status of bovine spermatozoa. When fresh bovine spermatozoa that had been fixed with 4% formaldehyde, smeared on glass slides and then air-dried were stained by FITC-ConA, weak fluorescence was observed on the acrosomal region, although almost all the spermatozoa appeared to be acrosome-intact. However, when fresh sperm suspensions were incubated with FITC-ConA and then mounted on glass slides, no fluorescence was observed on the acrosomal region. Therefore, in the ensuing experiments, both the fixation and the FITC-ConA staining of spermatozoa were done in suspension. When ethanol-treated spermatozoa, whose outer membrane may be permeabilized, were stained with FITC-ConA, the fluorescence was extensively observed on the inner acrosomal region. This fluorescence was inhibited in the presence of 0.2 M D-mannose, a competitive sugar, suggesting that FITC-ConA binds specifically to glycocomponents on the inner acrosomal membrane. We next tried to stain fresh or frozen-thawed spermatozoa from 3 different bulls that had been treated with the calcium ionophore A23187, which is known to induce acrosome reaction of bovine spermatozoa, with FITC-ConA. A significant correlation between the percentage of ConA-labeled spermatozoa and that of rose bengal stained negative ones at various time points during A23187 incubation was achieved. Furthermore, suitability of dual staining to distinguish between physiological acrosome reaction (acrosome-lost and live) and degenerative acrosomal loss (acrosome-lost and dead) using FITC-ConA and Hoechst bis-benzimide 33258 (H258) supravital stain was also confirmed. From these results, it was concluded that the FITC-ConA labeling procedure is a feasible and reliable method for the assessment of physiological acrosome reaction of bovine spermatozoa.

13 MANAGEMENT SYSTEM FOR FROZEN BULL SEMEN USING A RADIO FREQUENCY IDENTIFICATION TAG

An appropriate traceability system is essential for safety during production and distribution of food products. In Japan, the ear-tag system has been applied for this purpose. In this system, newborn calves are tagged individually with a bar code, and are registered to the database, so that everyone can know the information regarding individual cattle and meat. However, the management of frozen semen and the validation of frozen straws are out of the scope of the system. A traceability system for beef production totally covering the progression from semen to meat is necessary for food safety and validation. We applied radio frequency identification (RFID) for the identification of individual frozen semen straws. RFID is the management technology that uses a small tag with a radio transmitter (RFID tag) that has recently been used in the field of distribution management. We consider this technology as a tool to trace artificial insemination (AI) data before the birth of a calf and to establish a management system for production of the Japanese Black cattle breed. The microchip (�-chip) we used as an RFID tag was manufactured by Hitachi, Ltd., Tokyo, Japan. The �-chip is the smallest RFID chip in the world (0.4 mm square) and has a unique identification number (capable of corresponding to 128 bits, 1038 in decimal notation) readable by the RFID tag reader. The �-chip was attached to the frozen semen straw by ultrasonic sealing. We demonstrated that the �-chip retained its function after being stored in liquid nitrogen for at least several months. The information for bull semen, which was dispensed into frozen semen straws with the attached �-chips, was stored in the system database, and the straws were stored in liquid nitrogen. These straws with the �-chips were distributed to local farmers and inseminated into recipient cattle; the AI conditions, results of pregnancy diagnosis, and birth conditions were recorded in the system database. This system using the �-chips may be useful for confirmation and acquisition of trust for a commercially valuable bull and for the study of the improvement of AI for reproduction.

89 ZYGOTICALLY ACTIVATED GENES ARE SUPPRESSED IN MOUSE NUCLEAR-TRANSFERRED EMBRYOS

Mammalian oocytes have the ability to confer totipotency to terminally differentiated somatic cell nuclei. Viable cloned animals have been produced by somatic cell nuclear transfer (NT) into oocytes in many mammalian species including mouse. However, the success rates of the production were quite low in all species. Many studies have measured differences in gene expression between NT and fertilized embryos in relatively advanced stages of development such as pre- and post-natal stages or the blastocyst stage. In the mouse, major zygotic gene activation (ZGA) occurs at the 2-cell stage after fertilization and leads to the transition of gene regulation from maternal control to embryonic control. Suppression of the ZGA by a transcription inhibitor was shown to decrease the viability of embryos, and causes developmental arrest at the 2-cell stage. An abnormal ZGA may therefore affect the viability of NT embryos and cause further abnormalities in later embryonic development. In the present study, we compared gene expression patterns using differential display RT-PCR (DDRT-PCR) between the NT and IVF embryos at the 2-cell stage to detect some abnormalities affecting later development of NT embryos. The developmental rate of NT embryos to blastocysts (32.9%) was significantly lower than that of IVF (92.7%) or PA (92.8%). In addition, the cell numbers of NT embryos at the blastocyst stage (39.5 � 2.6; n = 19) were less than those of IVF (66.8 � 2.1; n = 30) or PA embryos (48.2 � 2.1; n = 30). Using these embryos, we first identified 4 genes that were differentially expressed between NT and IVF embryos at the 2-cell stage. Among the identified genes, Inpp5b and Chst12 were up-regulated, and MuERV-L and Dnaja2 were down-regulated in the NT embryos compared with IVF embryos. Further analysis showed that the expression of zygotically activated genes such as Interferon-γ, Dub-1, Spz1, DD2106, and DD2111 were not properly activated in NT embryos, suggesting that the cellular process involved in the control of the zygotic genome activation is not appropriately regulated. These results indicate that abnormal gene expression has already occurred at the early stage of pre-implantation development as a failure of nuclear reprogramming.

65 NUCLEAR REPROGRAMMING OF PORCINE CELLS AND THEIR USE AS DONOR CELL FOR NUCLEAR TRANSFER AFTER TREATMENT IN XENOPUS EGG EXTRACTS

Revealing an adequate cell state for nuclear reprogramming is essential to achieve efficient production of cloned embryos and animals. Previous reports suggest that nuclei from undifferentiated cells such as blastomeres or embryonic stem cells can support efficient development of cloned embryos to term. In recent years, differentiated somatic cells are frequently used for donor cells because of ease of preparation and application for genetic modification. The efficiency of the somatic cell nuclear transfer (SCNT) is still extremely low. We hypothesized that somatic cells that had been reprogrammed to dedifferentiated states before SCNT might support higher developmental ability of SCNT embryos. To test this hypothesis, porcine fibroblast cells were treated with Xenopus egg extracts, and the extract-treated cells (ETCs) were used as donor cell for SCNT to examine their ability to support early embryonic development. Xenopus egg extracts were prepared from activated S-phase eggs. Porcine fibroblast cells (106/mL) were permeabilized by 500 ng mL-1 of Streptolysin O and were incubated in the egg extracts with the energy-regenerating system for 2 hours at 23�C. After the extract treatment, permeabilized membranes were resealed in DMEM containing 2 mM CaCl2. The ETCs were fused with porcine enucleated oocytes and simultaneously activated. The reconstructed embryos were cultured in PZM-3 medium for 7 days. All statistical differences were analyzed by ANOVA. Reprogramming of ETCs was evaluated on changes of chromatin states and gene expression. Chromatin-binding proteins of ETCs were separated and analyzed on SDS-PAGE. Some proteins were incorporated onto and/or released from chromatins after the extract treatment. Especially, Xenopus egg-specific linker histone B4 was assembled on chromatins. Non-permeabilized control cells did not show these protein exchanges. Deacetylation of histone H3 lysine9 was detected in half number of ETCs in an ATP-dependent manner. In contrast, a high population of histone H3-acetylated cells was observed in buffer-treated cells as well as cells before the extract treatment. The pluripotent marker gene expression, such as OCT4 and SOX2, was also observed in ETCs after culture. The gene expression of these genes was not detected in non-treated cells. These results indicate that the extract treatment induces or triggers a part of dedifferentiation of somatic cells. These ETCs were used as donor cell for SCNT, and reconstructed cloned embryos were cultured. SCNT embryos showed no significant difference in cleavage rates and developmental rates to the blastocyst stage (25%) compared with non-treated control cells (26%). However, the total cell number of embryos at the blastocyst stage was significantly higher in SCNT embryos from ETCs compared with those of control cells (62 � 7 vs. 43 � 2, respectively; P &lt; 0.05). These results indicate that the extract treatment before nuclear transfer may stimulate cell proliferation of SCNT embryos but not improve early development. More studies, however, are needed to investigate their developmental ability to term.

146 LECTIN DOLICHOS BIFLOURUS AGGLUTININ (DBA) IS A SPECIFIC MARKER for PRIMITIVE GERM CELLS IN NEONATAL PORCINE TESTIS

Livestock transgenesis is primarily directed towards improving productive traits or for biomedical research. Transgenic pig is of immense interest because it could provide tissues and organs for xenotransplantation to humans. Conventional methods like pronuclear microinjection of zygote and, more recently, somatic cell nuclear transfer (SCNT) have been used for generating genetically modified pigs. These methods are, however, inefficient and have numerous shortcomings. Male germline stem cells have enormous potential, because they could serve as an alternative approach to generate genetically modified pigs, in which the homologous recombination technique could be applied. However, this could not be achieved due to lack of knowledge of culture conditions and markers that can distinguish germ cells from somatic cells, enabling their isolation and identification in culture. Lectin dolichos biflourus agglutinin (DBA), which has specific affinity for ?-d-N-acetyl-galactosamine, reacts with the large round primordial germ cells of the pig genital ridge (Takagi et al. 1997 Mol. Reprod. Dev. 46, 567–580). Immunohistochemical analysis of testicular samples from different age groups revealed that DBA binds to primitive germ cells in neonatal pig testis like gonocytes and pre-spermatogonia. Variable DBA affinity among germ cells and its progressive loss with age suggested that DBA bound strongly to gonocytes, weakly to undifferentiated spermatogonia, and not at all to spermatogonia. The presence of alkaline phosphatase activity in germ cells from neonatal pig testis further confirmed the existence of primitive germ cells. Gonocytes from neonatal pig testis were isolated using 2-step enzymatic digestion and discontinuous Percoll density gradient. Approximately 70% gonocytes were present in the fraction 5 (50–60% gradient) that were identified by their DBA affinity. Isolated cells were cultured in DMEM/F12 supplemented with 10 �g mL-1 of insulin, 10 �g mL-1 of apo-transferrin, 100 U mL-1 of penicillin, 50 �g mL-1 of streptomycin, 40 �g mL-1 of gentamycin sulphate, 1 mM pyruvate, 1� non-essential amino acid solution, and 10% fetal bovine serum at 37�C in 5% CO2 in air in a humidified atmosphere. Initially, gonocytes grew as adherent cells that formed foci of flat colonies. These colonies grew in size during the culture period, and DBA-positive cells were observed. Flat colonies transformed to ES-like colonies by 6–7 days of culture, which were still positive for DBA binding. Proliferation of germ cells was evaluated by double immunostaining with DBA and anti-bromodeoxyuridine (BrdU) antibody following BrdU incorporation, suggesting that 53–55% DBA-positive cells were in S phase after 7 days of culture. In conclusion, lectin DBA is a marker for porcine primitive germ cells in neonatal pig testis including gonocytes that could be used for their identification during isolation and in culture. Isolated gonocytes could proliferate in vitro without specific growth factor supplementation.