We examined sixty-three human embryos ranged from three weeks to eight weeks of fertilization age and 117 human fetuses from eleven weeks to fourty weeks of gestational age. Anatomical structure of developing tongue could be classified into eight developmental stages. The first is the sgage of mesial swelling of tongue primordium in the fertilization age of 28~40 days (Streeter stage 13~16), the second is the stage of lateral swelling of tongue primordium in the fertilization age of 41~46 days (Streeter stage 17~18), the third is the sgage of vertical positioning of tongue in the fertilization age of 47~53 days (Streeter stage 19~21), the fourth is the transitional stage of tongue from vertical position to horizontal position in the fertilization age of 54~56 days (Streeter stage 22~23), the fifth is the stage horizontal positioning of tongue in the gestational age of 11 weeks, the sixth is the stage of protrusion of tongue in the gestational age of 12 weeks, the seventh is the stage of maturation of tongue muscle in the gestational age of 7-10 months. The development of tongue papilla characteristically progresses into three stages. The first stage is the epithelial ingrowth for the crypt formation, the second stage is the anatomical formation of vallate, fungiform and filiform papillae, and the third stage is the differentiation of taste buds in the vallate and fungiform papillae or the formation of thick spike-like keratinization at the tip of filiform papilla. We observed that the tongue primordium mainly derived from occipital myotome developed more repidly than other oro-facial structures, so it transitionally occuied the spaces of the pharynx and the posterior nasal cavity, and directly affected the formation of palate and the growth of maxilla and mandible. Whereas the tongue papilla development showed continuous developmental sequences during the fetal period.
Humans

In order to elucidate the developmental stages of human tooth germ during prenatal period, we examined 254 normal fetuses ranging in gestational age from six weeks to fourty weeks old histologically. Lim's developmental pattern of prenatal tooth germ was divided into three groups, the first group consisting of five grades (I, II, III, IV, V) was for the development of enamel epithelium the second group of three grades was for the deposition of dentin matrix and enamel matrix, and the third group of three grades (A, B, C) was for the growth of perifollicular bone. Some developmental progress between enamel epithelium and dental papilla could be identified by observation of the sequential development of deciduous and permanent tooth germs histologically. The following results were made. 1) The prenatal development of tooth germ showed similar weekly stages in both the maxilla and the mandible. The initial deposition of dentin matrix and enamel matrix (III-1 stage) started at 12-14 weeks of gestational age in the deciduous incisor and canine, and at 16-20 weeks of gestational age in the deciduous molars. And the initial deposition of dentin matrix and enamel matrix in the permanent first molar was at 20-22 weeks of gestational age, and that of the permanent incisor was at 34-36 weeks, and that of the permanent canine was 36-38 weeks, and of the permanent premolar was at 38-40 weeks. 2) The S-shaped curvature was characteristically found where the reciprocal induction of odontoblast and amelobast occurred actively in the developing tooth germ. Primarily pre-ameloblasts which abutted on the dental papilla differentiate the condensed mesenchymal cells into odontoblasts, and secondarily matured odontoblasts which bulged into enamel epithelium produced dentin matrix and differentiated the shrunken pre-ameloblasts into ameloblasts. 3) The mandible grew more rapidly than the maxilla during the early prenatal period. The trabecular bone from both jaws proliferated initially into labial side of developing tooth follicle and gradually circumscribed the tooth follicle lingually and mesio-distally, to form perifollicular bone resultantly.
Humans

This study is aimed to observe the expressions of different genes, including the extracellular matrix proteins, growth factors, and transcription factors during different developmental stages of mouse submandibular gland. Reverse transcription-polymerase chain reaction (RT-PCR) and the antisense inhibition in organ culture system were performed using mouse embryos and newborns. Total 140 mouse embryos (E14(80), E15(20), E16(20), E18(20)) and 30 newborn mice (D2(10), D3(10), D6(10)) obtained from 60 pregnant mice and 3 adult mice (3 weeks old) were used for the cDNA production and the salivary gland organ culture. Syndecan, perlecan, laminin alpha1 chain, TGF beta1, beta 3, and sonic hedgehog mRNAs were expressed in the early stage (E14~E16) of the submandibular gland development, whereas transglutaminase C (TGase C), E-cadherin, epimorphin, laminin beta2 and gamma1 chains, and HGF mRNAs were expressed in the middle and late stages (E16~E18, D2~D6). Antisense inhibition of different genes in the organ culture of E14 mouse embryos of submandibular gland showed specific growth retardation in the development of ductal and acinar cells. Especially, the antisense inhibition of perlecan, E-cadherin, laminin alpha1 chain, laminin beta2 chain, and syndecan mRNA arrested the growth of ductal and acinar cells. While the antisense inhibition of integrin beta5 greatly affected the acinar cell differentiation and also produced cystic dilatation of salivary ducts, the antisense inhibition of fibronectin showed aberrant growth of ectomesenchymal tissues of the mouse submandibular gland.
Acinar Cells ; Adult ; Animals ; Cadherins ; Dilatation ; DNA, Complementary ; Embryonic Structures ; Extracellular Matrix Proteins ; Fibronectins ; Gene Expression* ; Hedgehogs ; Humans ; Infant, Newborn ; Intercellular Signaling Peptides and Proteins ; Laminin ; Mice* ; Organ Culture Techniques* ; RNA, Messenger ; Salivary Ducts ; Salivary Glands ; Submandibular Gland* ; Syndecans ; Transcription Factors

Five fetal maxillas were obtained from the autopsy file of fetal postmortem examination, and were examined by serial micro-sections of frontal plane and horizontal plane. Especially the area around the incisive canal of the maxilla was carefully observed. The results are as follows. 1) In 5 fetal maxillas extra-dental laminas and supernumerary tooth germs which are severely malformed in shape are found in the dilated incisive canal, where prominent vessels and nerves are distributed. 2) The supernumerary tooth germs disclose almost normal histo-differentiation of odontoblast and ameloblast, and there shows relatively abundant perifollicular fibrosis in the place of perifollicular bone. 3) It is observed that the over-growth of the extradental lamina from the dental ridge of deciduous central incisor frequently tends to direct toward the incisive canal that includes prominent vessels and nerves.

Meningioma is one of the most common intracranial tumor in adult. The tumor, however, occurs very rarely outside the central neuraxis, such as orbit, nasal cavity of parotid area. We report a case of extracranial meningioma in the parotid area. A 38-year-old man was presented with a round mass in the left parotid area. Magnetic resonance imaging revealed a round mass attached to anterior pole of the left parotid. The mass was easily separated from facial nerve. Microscopically, the mass was composed of ovoid or spindle cells. The tumor cells tended to show bundle formation, lobular arrangement and occasionally whorling appearance. This case is important at the means that meningioma should be included in differential diagnosis of mass in the parotid area.
Adult ; Male ; Female ; Humans ; Diagnosis, Differential ; Meningioma

No abstract available.

No abstract available.

No abstract available.
Arthritis, Infectious* ; Hip Joint* ; Hip*

Beckwith-Wiedemann syndrome is a rare clinical entity characterized by exomphalos, macroglossia, macrosomia, and renal hyperplasia/dysplasia. Although its entity is established, its etiology and obligatory features have not been settled. We report an autopsy case with the unusual involvement of the salivary gland. This infant was born to a 37-year-old mother as a normal full-term spontaneous delivery. At 11 days of age she developed with purulent eye discharge and weak sucking, and died suddenly. At autopsy the baby weighed 2,630 gm and the head circumference was 35 cm. She showed thick and prominent skin folds, bilateral aural fissures, macroglossia, hepatomegaly, cardiomegaly, dysmorphic kidneys, and nesidioblastosis. Both kidneys showed dysplastic tubules and hyperplastic cortical tissue enclosing the medulla. In this case there were characteristic findings in major and minor salivary glands with both acinar and ductal hyperplasia, and hypertrophy of mammary glands. Besides, she had generalized depletion of subcutaneous fat, immature buccal fat, patent ductus arteriosus, hyperlobation of the right lung, two accessory spleens, and hyperplasia of basophils and chromophobes in the pituitary gland. The lungs showed diffuse interstitial pneumonia and multiple fibrin thrombi. There were no adrenal cytomegaly, umbilical hernia and exophthalmos.
Infant ; Male ; Female ; Humans

Laminin-1 is biologically active and can effect cellular proliferation, differentiation, migration, and apoptosis. In the central nervous system, neuronal cells are rarely reported to give positive reaction by laminin antibody staining. However, the original cell type which can produce the laminin molecule has not been well established. Since the neuronal cells of brain are derived from neuroectoderm, we thought that the neuronal cells should be able to produce the laminin molecules as other epithelial cells. In this study we aimed to explore whether the neuronal cells express the laminin chain mRNAs, and further to identify which types of laminin isoform are expressed at the specific sites of the brain structure. We found that neuronal cell was the important cell type in mouse brain, which could produce laminin isoforms. Although immunostainings disclosed reactivity of laminins in the basement membrane of capillaries as well as neuronal cells, mRNA expressions of laminins were intense only in the neuronal cells. It was relatively weak in the endothelial cells. Among neuronal cells the cortical cells of cerebrum, pyramidal cells of hippocampus, and Purkinje cells of cerebellum showed pronounced expression of laminin chain mRNA. Glial cells, especially astrocytes, were negative for laminin subtypes both in immunohistochemistry and in situ hybridization. Taken together, our data indicate that the neuronal cells of mouse brain actively produce laminin isoforms, and the resultant polymerized laminins are accumulated mainly in the basement membrane of capillaries. In conclusion, the results indicate that neuronal cells produce and utilize the different laminin chains to maintain the neurovascular environment of brain.
Animals ; Apoptosis ; Astrocytes ; Basement Membrane ; Brain* ; Capillaries ; Cell Proliferation ; Central Nervous System ; Cerebellum ; Cerebrum ; Endothelial Cells ; Epithelial Cells ; Hippocampus ; Immunohistochemistry ; In Situ Hybridization ; Laminin* ; Mice* ; Neural Plate ; Neuroglia ; Neurons* ; Polymers ; Protein Isoforms ; Purkinje Cells ; Pyramidal Cells ; RNA, Messenger