Growth of mouse embryos implanted in the subcutaneous tissue of recipient mice

Eight-days-old mouse embryos were transferred to the subcutaneous tissue of the dorsal skin of host mice. A high rate of embryos developed into hemorrhagic (HN) or nonhemorrhagic nodules (NHN). The latter had trophoblastic cells as well as embryoblastic derivatives whereas HN contained almost only trophoblastic cells. At least two kinds of trophoblastic cells were present in NHN: small cells and large cells similar to trophoblastic giant cells. In HN most trophoblastic cells arranged themselves into a network whose meshes contained host blood. Although embryoblastic derivatives such as endoderm and Reichert's membrane were apposed to host connective tissue cells, trophoblastic cells were always surrounded by collagen fibrils or by a layer of an amorphous material.     

A Neoplastic Connective Tissue Mast Cell Capable of Continuous Growth In Tissue Culture

A neoplastic connective tissue mast cell from a dog mast cell sarcoma has been grown in tissue culture for 50 passages over a period of 2 years. The cells were grown as monolayer cultures in glass bottles, using Eagle's basal medium fortified with calf serum. The cultures were contaminated with an Alkaligenes sp. for 10 months but finally were sterilized bacteriologically by treatment with specific antiserum combined with antibiotics. The cells grow in a fibroblastic pattern, and contain mitochondria, mast cell granules, and lipid granules or droplets. The mast cell granules stain basophilic with Giemsa's stain and metachromatically with azure A or toluidine blue. They also stain with Sudan black B and with periodic acid-Schiff stain. The interphase nuclei are vesicular, contain from 1 to 20 nucleoli, and frequently show bizarre outlines. Multinucleate cells are often seen, as are mitotic figures. Extracellular fibrous material occurs in all cultures and apparently originates from the cell surface. This material does not have the structure of connective tissue fibers and has not been identified. The cells develop an increased number of metachromatic granules when grown in medium containing heparin and an increased number of sudanophilic granules when grown in medium containing stearic acid. Only small amounts of histamine were present in the tumor from which this cell line was derived and in the cells grown in tissue culture.     

Investigation of the representativeness of a single endometrial sample and the use of trichrome staining to aid in the detection of endometrial fibrosis in the mare

The uteri of five mares were removed and endometrial samples were procured from 12 specific locations in the uteri and the samples were processed and duplicate sections were stained with hematoxylin and eosin (H&E) or Masson's trichrome stains. The samples were interpreted in a blind manner by one person, and pathologic changes were classified according to Kenney (1). An assessment of stromal fibrous connective tissue and focal periglandular fibrosis or fibrotic nests was made. There were no significant differences in luminal epithelial cell heights or in the occurrence and severity of stromal fibrous connective tissue, focal periglandular fibrosis, or lymphatic lacunae among locations (P > 0.05). There was an effect of location on the occurrence and severity of inflammation (P < 0.05). If only inflammation was considered in categorization, this would have resulted in changing the category in 9 of 60 samples. There was no increase in tendency for inflammation, fibrosis or lymphatic lacunae to occur in the horns versus the body of the uterus, nor of the dorsal versus the ventral uterus (P > 0.05). There was no effect (P > 0.05) of type of stain on the ability to detect incidence and severity of focal periglandular fibrosis. There was an effect (P < 0.05) of type of stain on the ability to detect the incidence and severity of stromal fibrous connective tissue. The use of the trichrome stain showed slightly increased distribution of stromal fibrous connective tissue.     

Isolation of Onchocerca gibsoni tissue from frozen nodules for biochemical use

A new procedure is described which enables gram quantities of adult Onchocerca tissue to be isolated from frozen connective tissue nodules, thus minimizing the risk of enzymatic degradation. Bovine connective tissue nodules containing adult Onchocerca gibsoni worms were obtained from Australia frozen at −70°C and sectioned while still frozen into 3 mm thick slabs. The sections were thawed immediately before use, worm segments removed, rinsed, pelleted, and flash frozen in liquid nitrogen. Quality of the isolated material was demonstrated by the presence of an intact adult epicuticle as determined by electron microscopy, and by the presence of viable uterine larvae and cells. This procedure is applicable to other nodule-forming worms such as Onchocerca volvulus and is suitable for investigations which require the isolation of labile molecules or those present in minute quantities.     

Amyloid in cytologic specimens. Differential diagnosis and diagnostic pitfalls.

OBJECTIVE: To describe and illustrate the characteristic features of amyloid in cytologic preparations and point out its diagnostic pitfalls. STUDY DESIGN: Five fine needle aspirates and one bronchial washing that contained amyloid were retrospectively reviewed. The aspirates were obtained from each of the five following sites: lung, occipital lymph node, thyroid gland, proximal humerus and subcutaneous soft tissue. Smears of all of the aspirates were stained with Papanicolaou stain, and in two cases they were also stained with Diff-Quik. Cell block sections were stained with hematoxylin and eosin. Congo red, CD45 and CD20 were used on selected cases. RESULTS: Amyloid appears as either flocculent material or irregularly shaped fragments with scalloped and pointed edges. The amorphous fragments are acellular and frequently associated with connective tissue cells. They stain eosinophilic to cyanophilic with Papanicolaou stain and deep blue with Diff-Quik. In two cases an exuberant giant cell reaction almost obscured the amyloid. In the thyroid aspirate, the amyloid was misinterpreted as colloid. In bronchial washings and lung aspirates, amyloid has to be distinguished from mucus, alveolar proteinosis, chondroid material and corpora amylacea. When circumferentially surrounded by lymphocytes or plasma cells, flocculent amyloid deposits may simulate adenoid cystic carcinoma. CONCLUSION: Amyloid can be easily overlooked or mistaken for other entities with similar staining qualities. Congo red staining can help to confirm the diagnosis.     

Experimental evaluation of ceramic calcium phosphate as a substitute for bone grafts.

Tricalcium phosphate (Synthos) is a bioceramic material which can be carved with a scalpel and wired into place as a bone graft would be. The process of bone replacement of the prosthesis begins with an ingrowth of cellular loose connective tissue, which is replaced later by dense connective tissue. Around the periphery of this dense fibrous connective tissue, osteoid tissue becomes evident and on later specimens this mixture seems to be converted to bone--which at first is in the form of spicules but later takes on the characteristics of lamellar bone (with tricalcium phosphate particles seen within its lacunae). The progressive replacement occurs in a circumferential pattern, but most heavily at the bone-prosthesis interface. Although the periosteum is beneficial, we do not feel that the major source of bone formation is as the soft tissue or subperiosteal area. The replacement of the tricalcium phosphate prosthesis is slower than we originally thought, or than reported by others. We have noted pockets of tricalcium phosphate, incompletely replaced, in dogs up to 18 months after implantation. We believe this may be related to the larger sized prostheses we used (2 x 2 cm blocks) with, therefore, longer distances that the ingrowth and calcification had to traverse.     

Isolation of Onchocerca gibsoni tissue from frozen nodules for biochemical use

A new procedure is described which enables gram quantities of adult Onchocerca tissue to be isolated from frozen connective tissue nodules, thus minimizing the risk of enzymatic degradation. Bovine connective tissue nodules containing adult Onchocerca gibsoni worms were obtained from Australia frozen at −70°C and sectioned while still frozen into 3 mm thick slabs. The sections were thawed immediately before use, worm segments removed, rinsed, pelleted, and flash frozen in liquid nitrogen. Quality of the isolated material was demonstrated by the presence of an intact adult epicuticle as determined by electron microscopy, and by the presence of viable uterine larvae and cells. This procedure is applicable to other nodule-forming worms such as Onchocerca volvulus and is suitable for investigations which require the isolation of labile molecules or those present in minute quantities.     

Elastic tissue in the limiting membrane of the human seminiferous tubule

The structure and distribution of elastic tissue were studied in the limiting membrane of the seminiferous tubule from normal human testis. The elastic and elastic-related fibers (oxytalan and elaunin) were recognized by their tinctorial and ultrastructural characteristics. The connective structures of the limiting membrane, including the fibrotubules and the amorphous material of the elastic system, were studied after tannic acid-glutaraldehyde fixation. Fibrotubules (oxytalan fibers) were observed in almost all intercellular spaces of the limiting membrane, closely related to the contractile cells; the elaunin fibers (patches of amorphous material surrounded by bundles of fibrotubules) were evident in the outermost layers. The function of this system of elastic tissue and myoid cells is discussed, considering the permeability membrane and the role of the myoid cells in the elastogenesis and contractility of the seminiferous tubule.     

Cason's Polychrome Stain for Celloidin Embedded Material

Casonrecently reported a rapid one-step modification of the Mallory-Heidenhaim connective tissue stain which has proven excellent for routine work because of its simplicityy and uniformity. However, the Cason modification was described for paraffin-embedded material. With celloidin blocks, used widely in neuropathology, there are two problems to be overcome in using a single polychrome stain: first, a selection of a differentiating fluid which acts uniformly; second, a method of dehydration and clearing which will not affect the clarity of the stain or produce cracking in the tissue.     

Rheumatoid nodules

Summary The presence and localization of fibrin and fibronectin in rheumatoid nodules were studied using an indirect immunoperoxidase technique on tissue specimens fixed in formaldehyde, embedded in paraffin and pretreated with pepsin and testicular hyaluronidase. Three zones characteristic for rheumatoid nodules was recognized. 1) Central area with necrosis, containing at least in part fibrinogen-antigenic material and fibronectin especially in the peripheral part of the necrotic area. 2) Around the necrosis a layer of mesenchymal cells in a palisade arrangement was found. Especially in the external part of this layer fibronectin was demonstrated around and between the cells, where fibrin was absent. 3) Peripherally, a zone of non-specific granulation tissue containing moderate amount of fibronectin decreasing towards the surround mature connective tissue, was seen. In the border of the cellular layer vessels were found in variable amount. In some of the vessels vasculitis was demonstrated with the presence of inflammatory cell infiltration, fibrin deposition and occasionally thrombosis. The pathogenesis of the inflammatory reaction in rheumatoid nodules is discussed.     

TISSUE DEGRADATION PATTERNS OF AMPHIBIAN TADPOLE TAIL: HISTOLOGICAL AND BIOCHEMICAL STUDIES

The pattern of tissue degradation in the tadpole tail of the bullfrog, Rana catesbeiana , was studied histologically and biochemically. Tadpoles at four metamorphic stages (premetamorphic stage, stage XIII; prometamorphic stage, stage XVIII; early to middle climax stage, stage XXII; late climax stage, stage XXIII) were examined. In the histological study, tissues were stained by two different methods, i.e., Masson's trichrome stain and Van Gieson's stain. The results are summarized as follows: 1) Muscle tissues degenerated earlier thatn connective tissues; 2) Collagen density increased as tissue degraded; 3) At stage XXIII, degenerating and fragmented muscle tissues, surrounded by connective tissues, were seen, and 4) At the late climax stage, cell density was greatly increased as compared to preceding stages.
The biochemical studies are summarized as follows; 1) The general catabolic pattern of tail proteins seems to differ between the premetamorphic and late climax stages; 2) The total hydroxyproline content per unit wet weight of the tail increased significantly at the late climax stage as compared to the premetamorphic stage, supporting the histological observations, and 3) Collagen degradation products were obtained at the late climax stage on Sephadex G-75 columns.     

A rapid connective tissue stain for glycol methacrylate embedded tissue

No reliable connective tissue stains for GMA sections were available until recently. However, the use of toluidine blue in combination with basic fuchsin appeared to be a rapid and reliable connective tissue stain for glycol methacrylate (GMA) embedded tissue.     

Distribution and organization of the elastic system fibres in healthy human gingiva

Summary The ultrastructural distribution and organization of the elastic system fibres, i.e. oxytalan, elaunin and elastic fibres, were studied by transmission electron microscopy and by an immunohistochemical method for the detection of elastin in healthy human gingiva. The morphological distribution of these fibres was characterized by the presence of oxytalan, elaunin and elastic fibres, respectively, in the upper, medium, and deep layers of gingival connective tissue. Anti-elastin antibody reacted with microfibrils and amorphous material of the elastic system fibres throughout the gingival connective tissue. These findings were interpreted as indicating that the microfibrils were associated with small amounts of elastin at their surface.     

Permeability properties of the subepithelial tissues of Necturus gallbladder

The permeability properties of the subepithelial connective tissue of Necturus gallbladder were evaluated by measurement of electrical resistance, dilution potentials and hydraulic water permeability. The gallbladder epithelial cells were removed by scraping and the underlying connective tissue placed in an Ussing chamber. The electrical resistance was 2.2 +/- 0.8 omega X cm2; the tissue was slightly cation selective relative to free solution. The subepithelial tissues restricted the rate of diffusion of small solutes to 50% of the free solution value. The hydraulic water permeability averaged 2.1 X 10(-2) cm/s per atm. We conclude that limitations of the area of subepithelium available for fluid movement are the most important factors in determining the restrictions to solute and water flow offered by the subepithelial tissues.     

A histochemical comparison of methylene-blue/acid fuchsin with hematoxylin and eosin for differentiating calcification of stromal tissue

Benign and malignant connective tissue tumors consist of a fibrous component that contains varying amounts of one or more types of bone or other calcified tissue. Diagnosis of these connective tissue tumors often poses challenges for pathologists, because it is difficult to differentiate the organic matrix of osteoid from hyalinized stroma. To establish a definitive diagnosis, it sometimes is advantageous to demonstrate histologically by special staining either the type of calcification or the presence or absence of calcification. We compared the efficacy of methylene blue-acid fuchsin (MB-AF) to hematoxylin and eosin (H-E) for connective tissue tumors suspected to contain calcifications and to devise an optimal staining technique for calcification that would be specific, simple, and cost- and time-effective. We examined 50 benign and 45 malignant connective tissue tumors that were suspected to contain calcifications. Sections were stained with H-E and MB-AF and evaluated. MB-AF stained bone pink, which contrasted with blue soft tissue. After MB-AF staining, osteoid was faint pink in a blue stromal background. Osteoid was not visualized in H-E stained sections; it was stained the same shade of pink as stromal tissue. Dystrophic calcification and cementum could be identified equally well using either staining technique, but contrast was better after H-E staining. MB-AF staining of bone was comparable to H-E staining and could be used effectively to stain bone and osteoid. MB-AF is a simple, single step procedure. It also stains cementum blue with faint blue rimming and dystrophic calcification bluish-pink, but it cannot be used as a specific stain for types of calcification other than bone and osteoid.     

痛风的临床病理特征分析并文献复习

目的:总结痛风临床病理特点。方法:回顾性分析1例痛风患者的生化机制、临床病理特征、刚果红染色、PAS染色特点、鉴别诊断要点,并复习相关文献。结果:患者主要临床表现为间断性多关节肿痛3年,加重伴发热3个月。体格检查发现患者有多发性皮下结节、多关节肿胀压痛。左腕、左肘皮下结节活检,经HE染色后光镜查见大量肉芽肿性病变,有的多核巨细胞内查见被吞噬的异物,有的病灶尚查见呈均质状物(尿酸盐结晶),其周围有较多异物巨细胞及纤维结缔组织包绕呈结节状,在结节的周边纤维血管周围可查见残留分化成熟的淋巴细胞及少数嗜酸性粒细胞。刚果红、PAS染色均为阴性。偏光显微镜下,刚果红未查见绿色强折光晶体,但见多量略呈淡黄色具有强折光性的晶体呈棒状或梭形。结论:痛风在刚果红染色偏光显微镜下观察呈淡黄色梭形或针状结晶,具有强折光性晶体,但这是否是痛风在刚果红染色的特征尚有待于进一步研究。     

Nevus lipomatosus cutaneus superficialis (Hoffmann-Zurhelle) in a chimpanzee (Pan troglodytes)

BACKGROUND: A 32-year-old, male chimpanzee (Pan troglodytes) kept in a zoo developed a focally extensive, proliferative, cerebriform, dermal mass at the left inner thigh extending to the inguinal region. After surgical removal, the mass recurred and extended progressively over a period of 5 years. METHODS AND RESULTS: At necropsy, a 20 x 20 cm large, well defined, papular and partly verrucous, rubbery mass composed of multiple large, soft nodules measuring up to 4 cm in diameter was observed in the left thigh and inguinal region. Histological examination revealed a multifocal expansion of the dermis by mature adipocytes that were arranged in small islands to large lobular aggregates. Dermal proliferations of adipocytes were almost completely separated from the subcutaneous adipose tissue. CONCLUSIONS: This is the first report of a unique lesion that resembles human Nevus lipomatosus cutaneus superficialis in a chimpanzee and is different from lipoma or liposarcoma.     

Changes in the Microvasculature and Interstitium of Aged Human Mandibles and Maxillae1

The present study describes the age changes to the microvasculature and connective tissue interstitium of the osteons and periosteums of aged human mandibles and maxillae. The mandibles and maxillae obtained from 14 and 19 year old males, respectively, were also studied. In the nutrient canals of the aged osteons, the walls of the arterioles and venules stained intensely PAS positive, and alcian blue negative. The walls of the blood capillaries were thick and strongly PAS positive. There was a deposition of PAS positive material in the connective tissue stroma of the nutrient canals which progressed to the obliteration of the canal space. Many of the nutrient canals exhibited diffuse calcification within the connective tissue interstitium localized around the blood vessels. The lacunae and canaliculi of those osteons in which the nutrient canals were partially or completely obliterated were filled with PAS material. None of these histochemical changes were seen in the osteons of young individuals. The microvasculature of the aged periosteum showed similar changes. The periosteal tissue consisted of thick collagenous bundles and few osteogenic cells. There was a thin darkly stained amorphous calcified layer forming the bone surface.     

Rheumatoid nodules. A lightmicroscopical study with special reference to fibrin and fibronectin

The presence and localization of fibrin and fibronectin in rheumatoid nodules were studied using an indirect immunoperoxidase technique on tissue specimens fixed in formaldehyde, embedded in paraffin and pretreated with pepsin and testicular hyaluronidase. Three zones characteristic for rheumatoid nodules was recognized. Central area with necrosis, containing at least in part fibrinogen-antigenic material and fibronectin especially in the peripheral part of the necrotic area. Around the necrosis a layer of mesenchymal cells in a palisade arrangement was found. Especially in the external part of this layer fibronectin was demonstrated around and between the cells, where fibrin was absent. Peripherally, a zone of non-specific granulation tissue containing moderate amount of fibronectin decreasing towards the surround mature connective tissue, was seen. In the border of the cellular layer vessels were found in variable amount. In some of the vessels vasculitis was demonstrated with the presence of inflammatory cell infiltration, fibrin deposition and occasionally thrombosis. The pathogenesis of the inflammatory reaction in rheumatoid nodules is discussed.