Expression of podoplanin in AMs is considered to be associated with neoplastic odontogenic tissues; this molecule might play a role in the collective cell migration of tumor nests in AMs. The pattern of expression of E-cadherin and vimentin suggests that invasion in AMs occurs in the absence of EMT. The migration and invasion mediated by podoplanin in AMs could be related to cytoskeletal reorganization.

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In amniote embryos, skeletal muscles in the trunk are derived from epithelial dermomyotomes, the ventral margin of which extends ventrally to form body wall muscles. At limb levels, ventral dermomyotomes also generate limb-muscle precursors, an Lbx1-positive cell population that originates from the dermomyotome and migrates distally into the limb bud. In elasmobranchs, however, muscles in the paired fins were believed to be formed by direct somitic extension, a developmental pattern used by the amniote body wall muscles. Here we re-examined the development of pectoral fin muscles in catsharks, Scyliorhinus, and found that chondrichthyan fin muscles are indeed formed from Lbx-positive muscle precursors. Furthermore, these precursors originate from the ventral edge of the dermomyotome, the rest of which extends towards the ventral midline to form body wall muscles. Therefore, the Lbx1-positive, de-epithelialized appendicular muscle precursors appear to have been established in the body plan before the divergence of Chondrichthyes and Osteichthyes.

Podoplanin is strongly expressed in KCOTs in comparison with OOCs. The pattern of staining for podoplanin in KCOT could be related to its neoplastic nature, and suggests a role of the protein in tumor invasiveness.

An increased risk of testicular cancer in men with infertility and poor semen quality has been reported. In view of the high cure rates for testicular germ cell tumours, increasing clinical importance is being placed on the protection of fertility. High-dose cytostatic therapy may be expected to cause long-term infertility. Thus, the standard procedure for fertility protection is the cryopreservation of ejaculated spermatozoa or testicular tissue before therapy. Four male patients with azoospermia and two patients with very severe oligozoospermia underwent onco-testicular sperm extraction (TESE). We attempted onco-TESE in patients with azoospermia and very severe oligozoospermia after orchiectomy. Of the patients with testicular germ cell tumours, four had spermatozoa in their testicular tissues. Sertoli cell-only syndrome was found in one patient, and one patient showed maturation arrest without the detection of spermatozoa. Three of six showed seminomatous germ cell tumour, two of six had nonseminomatous germ cell tumour and one patient showed no malignancy. Two patients achieved clinical pregnancy. Fertility challenges in men with cancer are the most straightforward because of the relative ease of obtaining and cryopreserving sperm. Testicular sperm extraction is a useful technique for obtaining spermatozoa before cytotoxic therapy in azoospermic and very severely oligozoospermic cancer patients.

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The incidence of chromosomal abnormalities was studied in 719 unfertilized human oocytes obtained from our in-vitro fertilization (IVF) programme. To make chromosome preparations, a gradual fixation/air-drying method was utilized. Of 388 oocytes successfully karyotyped, 70 (18.0%) were abnormal. The abnormalities included 33 aneuploidies (8.5%) (14 hyperhaploidies and 19 hypohaploidies), 25 diploidies (6.4%) and 15 structural abnormalities (3.9%), three of them being accompanied by aneuploidy. Of the 33 aneuploidies, 16 (48.5%) showed the loss or gain of dyads (so-called non-disjunction), while 17 (51.5%) showed the loss or gain of monads (so-called predivision). There was no maternal age-dependent increase in the incidence of aneuploidy. Unfertilized oocytes from patients with a high fertilization rate (>25%) had a significantly higher (11.4%, P < 0.05) incidence of diploidy compared with the oocytes from the remaining patients (4.3 and 4.0%), suggesting that diploid oocytes might have a lower fertilizing ability.

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