鸡和大鼠小脑发育的比较观察

观察发育阶段不同的鸡和大鼠的小脑标本外形,并在光学显微镜和电子显微镜下观察了结构。鸡卵在孵育的第6天,小脑原基出现。第15天小脑皮质形成,普肯野氏细胞(普氏细胞)排成一层。新生鸡小脑皮质发育近成年状态,普氏细胞发育基本完成。大鼠在生后第5天小脑皮质形成,第20天发育成熟。在生后第5天普氏细胞排成一层,第20天接近成熟状态,此时在电子显微镜下显示为粗面内质网和多聚核蛋白体区域性集中分布。鸡小脑比大鼠小脑发育早,这是种属差异。     

Carcinoma-in-situ of the testis: possible origin from gonocytes and precursor of all types of germ cell tumours except spermatocytoma

Based on evidence from morphological and histochemical studies and from clinical experience, the following hypotheses are proposed: carcinoma-in-situ (CIS) germ cells are malignant gonocytes; these CIS gonocytes have some capacity to regress into more primitive, totipotent embryonic cells which can give rise to all types of nonseminomatous germ cell tumours; the tumour germ cells of classical seminomas are malignant gonocytes derived from CIS gonocytes which have lost their ability to regress into totipotent embryonic cells; the ability of CIS gonocytes to regress into totipotent embryonic cells decreases with age, whereas the capacity to form classical seminoma cells is preserved; the transformation of CIS gonocytes into invasive tumours is dependent on factors such as gonadotrophins and/or testicular steroids; the pathogenesis of classical and spermatocytic seminoma are unrelated. As a consequence of these hypotheses an alternative nomenclature for carcinoma-in-situ, seminoma and dysgerminoma is suggested.     

Phenotypic modulation in cisplatin-resistant cloned cells derived from transplantable rat malignant fibrous histiocytoma

The histogenesis of malignant fibrous hlstlocytoma (MFH) was studled using clsplatln (CDDP)-resistant MT-R8 and MT-R9 cells derlved from cloned undlfferentiated MT-8 and flbrohlstlocytic MT-9 cells, resoecthfely, which had been established from transplantable rat MFH. CDDP concentrations requlred for 50% suppression of prollferation of MT-R8 and MT-R9 cells were 5.4– and 3.3-fold greater than those of parental MT-8 and MT-9, respectively. MT-R8 and MT-Rg showed the higher positive rates to histimytic lysosomal/ antigenic (ED1 and ED2) markers. The number of a-smoath muscle actin (SMA)-positive cells significantly Increased in MT-RB; SMA-positlve cells were also obsenred in MT-R9, but no difference was seen between MT-9 and MT-R9. MT-R8 and MT-R9 expressed both histiwytic and myofibroblastic phenotypes. However, the histology of subcutaneous tumors induced in syngeneic rats by MT-R8 and MR-R9 did not always reflect their in vitro nature. MT-R8 developed undiffer-entlated sarcomas similar to parental MT-8 tumors. In contrast, MT-R9 induced tumors with polytypic histologies such as the storiform growth pattern, neoplastlc growth of granular cells and myofibroblasts, osteosarcoma-like areas, collagen-rich areas containing well-developed fibroblasts and areas involvlng many lipoblasts. These In vivo observatfons suggest the multidlrectional differentiation of MT-R9 cells. Phenotypic modulation of rat MFH cells seemed to be easily induced by CDDP. A possible histogenesis of MFH was discussed based on the data collected.     

Mucinous cystadenoma of the testis

A 35-year-old man complained of a painless enlargement of the right testis. Imaging diagnostic procedures demonstrated a multiloculated cystic tumor, 9 cm in maximal diameter, in the right testis with hydrocele. Orchidectomy specimen showed that the tumor was confined within the testis and separated from the epididymis. The locules of the tumor were lined by single-layered columnar epithelium, intermingled with MUC2 immunopositive goblet and chromogranin-A immunopositive neuroendocrine cells, exhibiting intestinal differentiation. No ciliated cell, teratomatous element or intratubular germ cell neoplasia were seen. Channels of rete testis were compressed peripherally by the tumor but there was no connection with the tumor locules. The tumor was diagnosed as mucinous cystadenoma of the testis. This seems to be the first published case of benign mucinous cystadenoma occurring within the testis. This intratesticular tumor with intestinal differentiation may represent a benign monodermal teratoma.     

3～20周人胚和胎儿肾小体的组织发生

应用光、电镜对3～20周22例人胚和胎儿肾小体的组织发生进行了观察.受精后第25天胚肾已有肾小体发生.随着胚龄的增长,肾小体的发生数目增多,肾小体的形成方式是:胚肾内先形成许多厚壁小管,在一部分厚壁小管的诱导下,另一部分厚壁小管的一侧壁呈帽状增厚,分化形成造血干细胞、毛细血管内皮及肾小囊脏层,对侧壁形成肾小囊壁层.即厚壁小管的双侧壁形成肾小体.     

Malignant fibrous histiocytoma of the pancreas

An extremely rare case of malignant fibrous histiocytoma In the pancreas Is reported. A 70-year-old man complained of upper abdominal discomfort. A tumor in the head of the pancreas was demonstrated by ultrasonography and computed tomography. The surgical specimen revealed a relatively well demarcated tumor, 9 × 7 × 6.5cm in size. Microscopically, fibroblastic, histiocytic, and muitinucleated giant tumor cells were observed in the myxoid area, but some tumor cells had proliferated in a storiform-pleomorphlc pattern. Immunohtstochemically, some tumor cells were positive for lysozyme, α-1-antitrypsin, α-1-antichymotrypsin, and vimentin. Electron microscopically, tumor cells showed a combination of fibroblastic and histiocytic features. The patient Is currently well with no evidence of recurrence or metastasis 22 months after operation.     

Developmental changes of chick cerebellar cortex revealed by monoclonal antibodies

Immunohistochemistry studies of the embryonic and newly hatched chick cerebellum were performed with 13 monoclonal antibodies (MAbs) raised against the embryonic chick optic nerve and a MAb which binds to cell nuclei. Neural MAbs differentially stained Purkinje cells, the external granular layer, molecular layer, internal granular layer, climbing fibers, basket cell axons, Bergmann glia and Ramón y Cajal's ansiform fibers. At the different developmental stages each component responded to MAbs differently. For example, staining of Purkinje cells with MAbs 23C10, 82E10 and 94C2 appeared on day 11 of incubation and disappeared sequentially after day 18. These results reveal molecular heterogeneity not only in cerebellar neurons but also at various developmental stages.     

Immunohistochemical study on histogenesis of congenital epulis and review of the literature

Congenital epulis is a very rare lesion found only in newborn infants. This tumor is multiple in about 10% of reported cases, rarely with the simultaneous involvement of the maxilla and mandibula, as in this article. In the presented case, light microscopy demonstrated large eosinophilic granular cells arranged in solid nests that are separated by thin fibrovascular areas. The tumors In the maxilla and mandibula were investigated with a panel of polyclonal and monoclonal antibodies, and using immunoperoxidase methods on formalin-fixed, paraffin-embedded sections. Immunohistochemical studies revealed strong and diffuse cytoplasmic staining for neuron specific enolase and vimentin. However, all other reactions were negative. These results suggest that the congenital epulis may be derived from uncommitted nerve-related mesenchymal cells.     

Developmental transition in plasticity properties of differentiating astrocytes: age-related biochemical profile of plasminogen activators in astroglial cultures

Plasminogen activator (PA) is a key enzyme in control of the cascade of extracellular proteolytic activities, proteases that degrade the extracellular components. Mammalian cells produce two molecular forms of PA, the urokinase type (u-PA) and the tissue type (t-PA); the u-PA type enzyme regulates cell migration/invasion and related tissue plasticity events. Thus, these plasticity properties of cells are defined by their PAs' biochemical profiles. The capacity of the differentiating glial cells of the central nervous system (CNS) to express and regulate the two types of PA activities has been examined as a function of cell age in culture. Results of the study suggest that only the immature astrocyte is endowed with these plasticity properties. Differentiating heterogeneous rat glial cells in culture express PA activity. Astroglia were identified as the primary source for the glial PA activity, as no PA activity was detected in the purified oligodendroglia. Cellular PA activity levels of differentiating rat and mouse astroglia are developmentally regulated. The specific activity of PA reached its highest level in rat astroglia at a cell age corresponding to 20-32 postnatal days (P20-P32) and in mouse astroglia at P8-P14; thereafter, this declined (three- to fourfold decrease) within 2 weeks to a low value. At comparable ages (P0-P35), the magnitudes of the PA specific activities of the differentiating rat astroglia and of the developing cerebrum, the tissue from which these cells were purified, were similar. Differentiating rat astroglia produce u-PA and t-PA, the cellular content of both is developmentally regulated, and the u-PA form is only found in the immature cells. u-PA is the predominant form in the immature astrocyte until age P13. Both forms are found in cells at ages P14-P30, and at later stages u-PA disappears while the t-PA type persists as the sole form. After 3 more weeks neither of the PA types was detected. Astroglia express also PA inhibitory activity; the rat astroglial PA inhibitor (PAI) seemed to be identical to PAI-1, one of the known types of PAIs. Stimulation of astroglial proliferation by their subculturing in contrast to Schwann cells did not lead to an increase; rather, beyond a certain cell age (P13) it resulted in a threefold irreversible decline in the PA specific activity of the daughter cells. It has been established that various biochemical properties of CNS mature glia appear on schedule with cell age in culture, thus defining "mature"glia in vitro.(ABSTRACT TRUNCATED AT 400 WORDS)     

Sebaceous carcinoma within rippled/carcinoid pattern sebaceoma

Although the histogenesis of sebaceous carcinomas remains unclear, the occurrence of intraepidermal or intraepithelial sebaceous carcinoma in the epidermis or conjunctiva may suggest de novo histogenesis. This report describes a case of sebaceous carcinoma within preexisting rippled/carcinoid pattern sebaceoma. This lesion was composed of two (benign and malignant) components, and the benign component of the lesion showed the typical features of a rippled/carcinoid pattern sebaceoma. Although evidence of trauma as well as a vertical orientation was seen in this lesion, the malignant component of the lesion showed histopathological evidence of malignancy (sebaceous carcinoma), such as the aggregations with irregular and infiltrated borders, a sheet‐like growth pattern, and the cytopathological findings of the neoplastic cells, showing a high‐grade of malignancy (a high mitotic index and abnormal mitotic figures). The immunohistochemical staining for p53, Ki‐67 and D2‐40 also favored this diagnosis. This sebaceous carcinoma component was considered to be the incipient stage of carcinoma within preexisting sebaceoma, therefore, it was still considered to be a vertically oriented lesion. This case shows the possibility that abnormal (malignant) sebaceous germinative cells may originate within a sebaceoma, thereby suggesting that some sebaceous carcinomas may develop from preexisting sebaceomas.