The histogenesis of the myofibroblast continues to be a controversial issue. The most popular view is that the myofibroblast is derived directly from the fibroblast. The important role of myofibroblasts in the synthesis of collagen and in wound contraction was demonstrated initially in granulation tissue in experimental animals. Four settings are recognized in which myofibroblasts are the principal proliferative cells: reparative responses, pseudoneoplastic disorders, stromal response to neoplasia, and true neoplasms, both benign and malignant. To identify of fibroblastic cells with smooth muscle differentiation features in the nonneoplastic and neoplastic lesions, we examined a variety of histological, immunohistochemical and ultrastructural features of 7 cases of granulation tissue, 7 of hypertrophic scar, 10 of chronic persistent hepatitis, 10 of chronic active hepatitis, 7 of liver cirrhosis, 7 of fibromatosis, 42 of cervical intraepithelial neoplasia, 14 of microinvasive carcinoma, 14 of invasive carcinoma, 7 of fibroma, 20 of fibrosarcoma and 72 of malignant fibrous histiocytoma. Antibodies against alpha-smooth muscle actin and desmin were used in a biotin-streptavidin procedures. The results of immunohistochemical and electron microscopical examinations yielded virtually identical findings. The identification of fibroblastic cells with smooth muscle cell differentiation features in the desmoplastic reactions of carcinomas, fibroma, fibrosarcoma and malignant fibrous histiocytoma offers also novel diagnostic and prognostic perspectives, that might help in evaluating preneoplastic lesions and malignant lesions. So degree of proliferative myofibroblasts was helpful diagnostic aid in differentiation of chronic persistent hepatitis, chronic active hepatitis and liver cirrhosis.
Animals

The immunohistochemical results are compared with ultrastructural features of neoplastic epithelial cells and mesenchymal cells to assess whether immunohistochemistry is useful in the differential diagnosis of epithelial tumors and mesenchymal tumors. Squamous cell carcinoma and transitional cell carcinoma exhibited positive reaction for keratin, but adenocarcinoma was weakly positive reaction for keratin. Ultrastructurally, heavy bundles of tonofilaments were more frequently encountered in squamous cell carcinoma. In adenocarcinomas, the intermediate filaments were arranged randomly as nonaggregated, short filaments spread throughout the cytoplasm. Fibroblastic and fibrohistiocytic tumors, schwannomas, and neurofibromas exhibited positive reaction for vimentin and alpha-smooth muscle actin. Vimentin consisted of large aggregates of gently curved filaments that often displace other cytoplasmic constituents was noted. Fibroblastic cells with features of smooth muscle differentiation were found in granulation tissue of healing wounds, hypertrophic scars, fibromatosis, fibroma, neurofibroma and malignant fibrous histiocytoma. Smooth muscle tumors showed abundant bundles of thin filaments with dense bodies, pinocytotic vesicles and dense attachment plaques along the cell membrane. Skeletal muscle tumors showed bundles of disorganized thick and thin filaments, remnants of sarcomeres and Z-bands. From the above result, ultrastructural and immunohistochemical studies on epithelial and mesenchymal tumors were useful in tumor diagnosis sand classification.
Diagnosis, Differential ; Adenocarcinoma

This study was designed to evaluate the effects of altered reticuloendothelial function on the formation of nospecific reactive hepatitis in rats. Increased activity of reticuloendothelial system was evoked by methylcellulose treatment (20 mg/100 g). Partial depression of reticuloendothelial system was induced by splenectomy. Experimental nospecific reactive hepatitis was made by Escherichia coli treatment, artificial stomach perforation ileum ligation, respectively. The nonspecific reactive hepatitis thus made evaluated by liver function tests such as AST ALT and alkaline phosphatase. Histological and electron microscopical observation were also done. The results obtained were as follows: 1. Functional and histological changes of nospecific reactive hepatitis deffered with the disign employed. 2. Partial reduction of reticuloendothelial activity by splenectomy didn't influence the serverity of nonspecific reactive hepatitis. 3. Increase of reticuloendothelial activity by methylcellulose treatmetns reduced the severity of nonspecific reactive hepatitis lesion developed by E. coli treatment and stomach perforation, both functionally and morphologically. 4. Changes of nonspecific reactive hepatitis by lieum ligations, however, were aggrevated by increased recticuloendothelial activity. These results showed the divers effect of altered reticuloendothelial function on the degree of nonspecific reactive hepatitis according to the employed experimental designs.

Cholelithiasis is defined as the presence of stones within the lumen of the gallbladder or in the extrahepatic biliary tree. Cholecystitis, secondary to gallstones, is a common surgical disorder in Korea. Detailed microscopic descriptions, particularly the ultrastructural changes, of these diseases were not available. The goal of this study was to identify the ultrastructural alterations of gallbladder epithelium in cholecystitis with and without a stone, according to the degree of severity of inflammation, and the nature of the stone. The gallbladders of the control group, and cholecystitis cases without stone and with stone were fixed and examined with routine stain, special stain, immunohistochemical stain and trans-mission electron microscopy. The number and the volume density of the mucin containing secretary granules were not significantly increased in the calculous cholecystitis cases compared with those of the acalculous cholecystitis cases. Major findings were that the calculous cholecystitis cases showed a markedly reduced total lysosome area and volume density of the lysosome compared with those of the acalculous chole-cystitis cases. The differences between the mucin secretary granules and lysosomes, according to the degree of severity of cholecystitis and the natures of gallstones, were statistically not significant.
Humans

The myoepithelioma is a rare salivary gland tumor composed nearly exclusively of myoepithelial cells. A case occuring on the parotid gland of a 51 year-old female is reported. Light microscopy finding revealed plasmacytoid cells. Ultrastructurally, the most of the neoplastic cells had polygonal outlines and showed eccentric, round to ovoid nuclei with even contours, peripherally distributed heterochromatin and to three small nuceoli. Their cytoplasms were almost completly filled with thin filaments, arranged in parallel strains and exhibiting "dense bodies". The neoplastic cells showed positive immunostaining for S-100 protein and cytokeratin.
Female ; Humans

The myoepithelioma is a rare salivary gland tumor composed nearly exclusively of myoepithelial cells. A case occuring on the parotid gland of a 51 year-old female is reported. Light microscopy finding revealed plasmacytoid cells. Ultrastructurally, the most of the neoplastic cells had polygonal outlines and showed eccentric, round to ovoid nuclei with even contours, peripherally distributed heterochromatin and to three small nuceoli. Their cytoplasms were almost completly filled with thin filaments, arranged in parallel strains and exhibiting "dense bodies". The neoplastic cells showed positive immunostaining for S-100 protein and cytokeratin.
Female ; Humans

The cholestasis are defined as blockade or secretory distrubance of bile and appearance of bile in hepatocytes, Kupffer cells and biliary passages, usually associated with dilated bile canaliculi. Intra-and extraheptic cholestasis were induced by 17-ethinyl estradiol, or chlorpromazine hydrochloride and by ligation of bile duct to investigate the mechanism of the hepatic injury, ultrastructural changes of liver and alterations of liver function. The results obtained were as follows. 1) Functional and histological changes of intra-and extrahepatic cholestasis differed in various experimental groups. The liver weight is increased in 17-ethinyl estradiol treated group and ligation of bile duct group (5.6+/-0.15, P<0.001, 5.3+/-0.19 gm/100 gm body weight, P<0.001). The common features of intra-and extrahepatic cholestasis were double membrane bounded amorphous vesicular material infiltrations in the cytoplasm of hepatocyte, partial loss of microvilli of bile canaliculi, anf focal thickening of pericanalicular ectoplasm on electron microscopy. 2) Intrahepatic cholestasis induced by 17-ethinyl estradiol show significantly increased serum level of alkaline phosphatase and total bile aicd (134.0+/-16.82 IU/L, 29.5+/-4.68 umol/l). Kupffer cell proliferation and focal cytoplasmic degradation with myelin figures are characteristic features on electron microscopy. Chlorpromazine hydrochloride induced intrahepatic cholestasis show increased serum level of AST, ALT, Cholesterol and bilirubin (156.9+/-11.32, 49.0+/-2.83 IU/L, 59.3+/-6.73 mg/dl, 1.8+/-.043 mg/dl). Inflammatory cell infiltration, chiefly lymphocytes and esoinophils are seen in periportal area. Prominent vesiculation and vacuolations of smooth endoplasmic reticulum are characteristic feature on electron microscopy. 3) Extrahepatic cholestasis induced by ligation of bile duct show increase serum level of AST, ALT, GGT, cholesterol, total bile acid, and bilirubin (290.2+/-50.24, 171.5+/-47.17, 159.3+/-24.54, 33.7+/-1.47 IU/L, 86.6+/-9.18 mg/dl, 246.6+/-27.34 umol/l, 13.9+/-0.83 mg/dl). Light microscopically, morphologic alterations are feathery degeneration of hepatocytes, proliferation of bile ducts, bile infarct and prominent intracytoplasmic lipid droplets. Electron microscopically, electron dense acidophilic body, bile casts and complete loss of microvilli are seen in dilated bile canaliculi. Also noted are hypertrophy of cannalicular ectoplasm. Finely granular materials are infiltrated in degenerative cytoplasm.
Rats ; Animals

Schneiderian papillomas are papillary lesions of the nasal cavity paranasal sinuses that arise from the Schneiderian membrane, a membrane of ectodermal origin embryologically derived from the nasal placodes. This membrane is characterized by transitional type epithelium, similar to bladder urothelium, with admixed microcysts or mucin droplets. It has a tendency to recur after removal and transform into malignancy even though rare. Total 27 cases of Schneiderian papillomas were examined in the Chosun University medical college, which were collected from 1978 to 1986. The results obtained were as follows: 1) There were 19 male and 8 female patients, and mean age at diagnosis was 50.5+/-12.0 (SD) year (27-74 years). 2) Nasal obstruction or perception of nasal mass was the most common presenting symptom; Mean duration of symptoms was 25.8+/-15.0 (SD) month (4-48 months). 3) Numbers of papillomas had predominantly endophytic (inverted, n=17) and predominantly exophytic (fungiofrom n=6) patients, and four had mixed pattern. 4) In 27 patients, recurrences developed in 9, local invasion in one (with an inverted papilloma), and epidermoid carcinoma in one (with an inverted papilloma).
Female ; Male ; Humans

This study was conducted to set up a common mechanism for varying phases of focal segmental glomerulosclerosis(FSGS) by comparing the morphological differences between human FSGS and changes in 5/6 renal ablation animal model, which has been accepted as experimental prototype for hyperfiltration theory as pathogenesis of FSGS. Both the human and the experimental rats showed very similar changes such as segmental glomerulosclerosis, vacuole formations or inclusion of small granules of podocytes, appearance of foamy cells in the capillary lumina, eosinophilic deposits along the mesangial area, and focal atrophy of tubules with associated interstitial fibrosis. The halo, frequently seen in human FSGS, is due to detachment of visceral epithelium from basement membrane, however, did not appear in the experimental rat specimen. On the other hand, the foamy cells and hyalinization were more frequently noted in the rat series and even involved the arterioles. The mesangial proliferation never appeared in the rat series occasionally found in human FSGS. In conclusion, the pathogenesis of FSGS cannot depend solely on the hyperfiltration theory of hemodynamic derangement, but has complex impairment of visceral epithelium and cells forming the constituents of basement membrane.
Animals ; Arterioles ; Atrophy ; Basement Membrane ; Biopsy ; Capillaries ; Eosinophils ; Epithelium ; Fibrosis ; Hand ; Hemodynamics ; Humans* ; Hyalin ; Models, Animal* ; Nephrectomy* ; Podocytes ; Rats* ; Vacuoles

This study was conducted to set up a common mechanism for varying phases of focal segmental glomerulosclerosis(FSGS) by comparing the morphological differences between human FSGS and changes in 5/6 renal ablation animal model, which has been accepted as experimental prototype for hyperfiltration theory as pathogenesis of FSGS. Both the human and the experimental rats showed very similar changes such as segmental glomerulosclerosis, vacuole formations or inclusion of small granules of podocytes, appearance of foamy cells in the capillary lumina, eosinophilic deposits along the mesangial area, and focal atrophy of tubules with associated interstitial fibrosis. The halo, frequently seen in human FSGS, is due to detachment of visceral epithelium from basement membrane, however, did not appear in the experimental rat specimen. On the other hand, the foamy cells and hyalinization were more frequently noted in the rat series and even involved the arterioles. The mesangial proliferation never appeared in the rat series occasionally found in human FSGS. In conclusion, the pathogenesis of FSGS cannot depend solely on the hyperfiltration theory of hemodynamic derangement, but has complex impairment of visceral epithelium and cells forming the constituents of basement membrane.
Animals ; Arterioles ; Atrophy ; Basement Membrane ; Biopsy ; Capillaries ; Eosinophils ; Epithelium ; Fibrosis ; Hand ; Hemodynamics ; Humans* ; Hyalin ; Models, Animal* ; Nephrectomy* ; Podocytes ; Rats* ; Vacuoles