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Based on mouse study findings, pancreatic islet cells are supposed to lack basement membrane (BM) and interact directly with vascular endothelial BM. Until now, the BM composition of human islets has remained elusive. Immunohistochemistry with specific monoclonal and polyclonal antibodies as well as electron microscopy were used to study BM organisation and composition in human adult islets. Isolated islet cells and function-blocking monoclonal antibodies and recombinant soluble Lutheran peptide were further used to study islet cell adhesion to laminin (Lm)-511. Short-term cultures of islets were used to study Lutheran and integrin distribution. Immunohistochemistry revealed a unique organisation for human Lm-511/521 as a peri-islet BM, which co-invaginated into islets with vessels, forming an outer endocrine BM of the intra-islet vascular channels, and was distinct from the vascular BM that additionally contained Lm-411/421. These findings were verified by electron microscopy. Lutheran glycoprotein, a receptor for the Lm α5 chain, was found prominently on endocrine cells, as identified by immunohistochemistry and RT-PCR, whereas α3 and β1 integrins were more diffusely distributed. High Lutheran content was also found on endocrine cell membranes in short-term culture of human islets. The adhesion of dispersed beta cells to Lm-511 was inhibited equally effectively by antibodies to integrin and α3 and β1 subunits, and by soluble Lutheran peptide. The present results disclose a hitherto unrecognised BM organisation and adhesion mechanisms in human pancreatic islets as distinct from mouse islets. [ABSTRACT FROM AUTHOR]

The product of Snail gene is a repressor of E-cadherin transcription and an inductor of the epithelial-to-mesenchymal transition in several epithelial tumor cell lines. In order to examine Snail expression in animal and human tissues, we have raised a monoclonal antibody (MAb) that reacts with the regulatory domain of this protein. Analysis of murine embryos shows that Snail is expressed in extraembryonic tissues and embryonic mesoderm, in mesenchymal cells of lungs and dermis as well as in cartilage. Little reactivity was detected in adult tissues as Snail was not constitutively expressed in most mesenchymal cells. However, Snail expression was observed in activated fibroblasts involved in wound healing in mice skin. Moreover, Snail was detected in pathological conditions causing hyperstimulation of fibroblasts, such as fibromatosis. Analysis of Snail expression in tumors revealed that it was highly expressed in sarcomas and fibrosarcomas. In epithelial tumors, it presented a more limited distribution, restricted to stromal cells placed in the vicinity of the tumor and to tumoral cells in the same areas. These results demonstrate that Snail is present in activated mesenchymal cells, indicate its relevance in the communication between tumor and stroma and suggest that it can promote the conversion of carcinoma cells to stromal cells.Oncogene (2006) 25, 5134–5144. doi:10.1038/sj.onc.1209519; published online 27 March 2006 [ABSTRACT FROM AUTHOR]

The aim of this study was to analyse microvascular damage and compensatory angiogenesis in skin from patients with systemic sclerosis (SSc) compared with systemic lupus erythematosus (SLE), Raynaud's phenomenon (RP) and healthy controls. Immunohistochemistry was used for skin biopsies (9 SSc, 10 SLE, 9 RP and 12 healthy controls) using von Willebrand factor and β3 integrin subunit specific antibodies, TechMate immunostaining robot and biotin-streptavidin protocol. In the early stages of SSc, vWF was found in the perivascular space and interstitial matrix in papillary but not in the reticular dermis, in particular around small oedematous blood vessels infiltrated by mononuclear cells. The extravascular release of vWF in SSc specimens was associated with weak or even a total lack of immunoreactivity within the associated endothelial cells. Late stages of SSc were characterised by loss of the dermal papillae, subepidermal fibrosis, hypovascularity and strong endothelial vWF expression without extravascular leakage. In all SSc patients studied only a few vascular profiles were weakly immunostained for β3 integrin subunit. This work demonstrates that vWF is not only released into the systemic circulation, but is also leaked to the perivascular space/matrix. This local release and deposition of vWF is probably a sensitive and early marker of microvascular involvement in SSc pathogenesis. Local vWF release may play a role in platelet adhesion, aggregation, thrombogenesis and dermal connective tissue remodelling. In spite of some attempts towards compensatory angiogenesis in SSc, as evidenced by β3 integrin subunit expression, it was evident that the angiogenic response was not able to prevent the development of hypovascularity during the advanced stages of the disease. [ABSTRACT FROM AUTHOR]

The distribution of tenascin-X (Tn-X) was investigated in synovial samples from rheumatoid arthritis (RA), osteoarthritis (OA) and knee injuries, and in synovial membrane-like interface tissue (SMLIT) from aseptic loosening of total hip replacement (THR). An affinity purified rabbit antiserum against Tn-X was applied in avidin-biotin-peroxidase complex method. Double immunofluorescence labeling was used to assess the spatial relationship of Tn-X and Tn-C. All samples showed Tn-X immunoreactivity. Strong staining appeared in the lining and lining-like layers of RA and SMLIT samples, respectively. An intensive immunoreactivity was also found in pannus tissue in RA, and around multinucleate giant cells and polyethylene wear debris in SMLIT. Staining intensity/extent varied significantly in different samples in the following rank order: SMLIT, RA, OA, knee synovium membrane. Double labeling revealed two patterns of Tn-X/Tn-C distribution, reciprocal and co-localization. Our results suggest that Tn-X is an essential component of normal synovial membrane, and that inflammatory mediators may increase local Tn-X production. Tn-X distribution is not always reciprocal to that of Tn-C. [ABSTRACT FROM AUTHOR]

Mast cells (MCs) have been implicated in many immune-inflammatory disorders. Deranged mast cell distribution and function may contribute to the local pathomechanisms in the labial salivary glands (LSG) in Sjögren's syndrome (SS). Evidence for MC presence, localization, frequency, subtype, and degree of activation was sought by using reverse transcriptase-polymerase chain reaction (RT-PCR), immunohisto-chemistry (IHC)/image analysis, transmission electron microscopy, Western blotting, spectrophotometric activity assay, and radioimmunoassay. The overall expression (densitometric units) of MC tryptase mRNA (1483 ± 228 vs 1044 ± 308) did not differ between SS and control LSGs. However, IHC disclosed an uneven distribution of MCs in SS with an absence in lymphocyte foci and increased numbers (cells/mm² 77 ± 7 vs 38 ± 4, P < 0.01) elsewhere. Absence of MCs in the lymphocyte loci was not a fixation artefact and was not explained by the presence of ‘phantom’ MCs in these areas. In both SS and controls, 80% of all MCs were chymase containing, but the typical lattices/gratings characteristic for connective tissue MCs (CTMCs) were not found. Instead, MC granules had mostly a homogeneous, finely granular substructure characteristic of ‘new’ granules subjected to a continuous, low-grade release. 32 kDa MC tryptase was found in saliva and its activity/concentration was comparable to that found in controls. However, tryptase output was low in SS (1.30 ± 0.30 μg/min vs 3.49 ± 0.66 μg/min, P < 0.001). Normal LSGs contain mostly CTMCs, in close contact with various resident and immigrant cells, characterized by a low-grade release of MC mediators. In SS this normal pattern is disturbed so that MCs are absent in lymphocyte foci (but increased elsewhere in the glands). The net salivary output of MC mediators is low in SS. This derangement of MCs may contribute to the pathogenesis of SS via multiple mechanisms. [ABSTRACT FROM AUTHOR]

Cytosolic determinations of cathepsin-D (cath-D), urokinase plasminogen activator (uPA) and its specific inhibitor PAI-1 have shown an association with adverse prognosis in breast cancer. Our aim was to study the distribution of these markers in small axillary node-negative breast carcinomas using immunohistochemistry and relate the semiquantitative results to known prognostic factors, the expression of tenascin-C (Tn-C) in invasion border of the tumour and prognosis. All the 158 women (159 tumours) were treated with breast conserving surgery and postoperative radiotherapy. Cytoplasmic immunoreactivity for cath-D was seen in carcinoma cells in 47% and in stromal cells in 44%. Nearly all tumours expressed uPA and PAI-1, which were categorized to cytoplasmic expression in carcinoma cells and diffuse stromal expression and quantified - / + / ++ / +++ and further dichotomized for purposes of analysis. Expression of uPA and PAI-1 in stromal fibroblasts was recorded as - / +. Cytoplasmic and stromal cell cath-D contents were associated with grade, proliferation, Tn-C expression in the tumour invasion border and the development of distant metastasis. In multivariate analysis stromal cath-D proved to be an independent prognostic factor for metastasis. Stromal expression of uPA was associated with an increased risk of local recurrence; otherwise high levels of uPA did not associate with other prognostic factors nor with prognosis. Fibroblastic expression of PAI-1 showed an association with both local and distant disease recurrence. However, no consistent association between the immunohistochemically quantified uPA and PAI-1 and prognosis was found. In conclusion, immunohistochemical determination of cath-D seems to be a viable method to predict a higher risk of metastasis but not local recurrence in small axillary node-negative breast carcinomas. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine the distribution of beta 1 and alpha v integrins (Ints) and some of their ligands in the kidneys of patients with congenital nephrotic syndrome of the Finnish type (CNF) and in controls using indirect immunofluorescence with monoclonal antibodies. The mesangial reactivity of Int alpha 1 and Int beta 1 subunits was more variable and an increased glomerular reactivity with Int alpha 3 and Int-alpha 6 antibodies was found in CNF kidneys than in controls. Int alpha 2 subunit was either completely missing from or found in significantly lesser amounts in CNF kidney glomeruli. The immunoreactivity for Int alpha v was more variable, fainter and also more granular in CNF samples than in control kidneys. The glomerular reactivity for Int beta 5 was more diffuse and weaker, and in sclerotic Bowman's capsules more intense in CNF kidneys than in controls. Immunoreactivity for Int beta 6 was restricted and was comparable in extent in CNF and control kidneys. Of the extracellular matrix components studied, the expression of EDAFn, EDBFn, OncFn, Ln alpha 2 chain, Ln beta 1 chain and tenascin was increased. This is also seen in several glomerular diseases with inflammation and sclerosis. Immunoreactivity for vitronectin was decreased. Several differences were found in the intensity or location of the immunostaining for the beta 1 and alpha v Ints and their ligands in CNF kidneys compared with controls, which have not been found in any other proteinuric disease. Disturbed Int expression pattern in CNF may specifically reflect the disturbance of glomerular function caused by the primary defect in this disease. [ABSTRACT FROM AUTHOR]

We studied the expression of tenascin (Tn) in human stomach. In the normal mucosa of the antrum and body, Tn reaction was only seen in the muscularis mucosae, in the region of the pyloric sphincter and in the duodenum, a Tn-immunoreactive rim was seen underlying surface epithelial cells. Antral gastritis, irrespective of the degree of inflammation, showed a rim-like Tn expression under the surface epithelial cells but no Tn reaction was seen in mild chronic gastritis of the body. In some moderate and severe examples of chronic gastritis a delicate Tn-reactive line was seen to underline the surface epithelium focally and the neck regions of gastric pits. Discontinuous Tn immunoreactivity was sometimes seen beneath hyperplastic epithelium in both parts of the stomach. A Tn-immunoreactive line was seldom seen surrounding glands showing intestinal metaplasia. In both benign and malignant ulcers prominent Tn immunoreaction was seen at the base of ulcers extending deep into the underlying muscularis. Only severely dysplastic lesions displayed Tn in the lamina propria, in close association with capillaries. In early forms of diffuse gastric cancer (DGCA) raggedly increased Tn staining was seen in the lamina propria underlying affected surface epithelial cells. In advanced forms of DGCA consistent Tn expression was seen in the tumour stroma. A distinct Tn reaction was seen surrounding invasive tumour cell nests of intestinal type gastric cancer (IGCA) in the submucosa, whereas in early forms of the tumour enhanced Tn reaction was noted predominantly in the upper part of the lamina propria in the vicinity of dysplastic elements. Notably, while most invading DGCA tumour cell nests showed no Tn in the submucosa and muscle cell layer, invading IGCA islets showed prominent expression of Tn. The most conspicuous Tn enhancement in the stomach is seen in invasive tumours and in ulcers suggesting that Tn is an important stromal component in malignant growth and in lesions undergoing active repair and remodelling. [ABSTRACT FROM AUTHOR]

In an attempt to find a reliable peripheral marker of Alzheimer's disease (AD), pieces of olfactory mucosa were removed by biopsy from 11 patients with probable AD and from eight control patients. The samples were analysed immunocytochemically using monoclonal and polyclonal antibodies. The olfactory and peripheral neurons of the olfactory mucosa in both AD and control patients typically exhibited immunoreactivity to neurofilament (NF) triplet proteins, including both phosphorylated and non-phosphorylated epitopes, as well as to synaptophysin, but lacked reactivity to other intermediate filament proteins, microtubule-associated protein 2 and tau. Our results do not support the recent findings suggesting the lack of NF proteins in olfactory neurons or the preferential phosphorylated status of NF proteins in olfactory neurons solely in AD. [ABSTRACT FROM AUTHOR]

The pathogenesis of a rare form of the ichthyotic diseases, ichthyosis hystrix Curth-Macklin, was investigated by immunohistochemistry and electron microscopy. Monoclonal antibodies (Mabs) against keratins expressed in normal basal cells (PKK and KA1), Mabs against keratins only present in normal fetal skin (PKK), and Mabs against keratins 1, 2, 10, and 11 (KA5 and K8.60) were used. The Mabs reacting with normal basal cells showed an increased reaction with many cell layers. The Mab PKK distinctly reacted with the basal cell layer, suggesting an expression of fetal keratins. Electron microscopic study of both normal-looking and involved skin revealed the keratinization disorder characterized by tonofilament shells, perinuclear vacuoles, and binuclear keratinocytes. The results suggest that there is no prematurity of keratinization, but rather a pathological expression of specific keratin genes leading to expression of fetal keratins in this form of ichthyosis hystrix. [ABSTRACT FROM AUTHOR]

•Background: Integrins, which are composed of an α and β subunit, are capable of binding to a number of extracellular matrix proteins and, hence, affect cell adhesion and proliferation. •Methods: The distribution of the integrin β (β, β-β) and α (α and α) subunits in human anterior chamber angle was studied in eyes from subjects aged 9 months to 81 years using the indirect immunofluorescence technique. •Results: Immunoreaction for the β subunit was found throughout the trabecular meshwork (TM), in the cribriform layer, and in the endothelial lining of Schlemm's canal (SC). Labelling for the α subunit was found in the TM and the cribriform layer only. In infant eyes the α subunit was present in all three areas with the highest concentration in the cribriform layer, whereas no reaction was observed in adult eyes. The α subunit was localized to the endothelium of SC only. Immunoreaction for the α subunit was present in the TM and the cribriform layer of infants and young adults. •Conclusion: The present results suggest the presence of several integrin heterodimers, acting as potential receptors for laminin, collagen, fibronectin, and vitronectin, in the anterior chamber angle. [ABSTRACT FROM AUTHOR]

Cultured human amniotic fluid cells consist of five different types of cytokeratin-positive epithelial cells, E-1 to E-5, differing by their size, growth morphology, and cytokeratin pattern, according to our earlier investigations. Using anticytokeratin antibodies in indirect immunofluorescence (IIF) microscopy, we show in this study that cultured urine cells contain four of the cell types found in amniotic fluid. In addition, we used two urothelium-specific antibodies, anti-UMA and anti-Las-86, in combination with cytokeratin antibodies to distinguish urothelium-derived cells in amniotic fluid and urine cell cultures. Two of the epithelial cell types were found to express urothelial antigens and thus to originate from the transitional bladder epithelium. These cells were found in 26 of the 33 amniotic fluid cell cultures and in nine of the ten urine cell cultures. [ABSTRACT FROM AUTHOR]

Antibodies specific for cytoskeletal intermediate (10 nm) filaments reacted both with the hyaline deposits in alcoholic liver disease (Mallory bodies) and with perinuclear hyaline material of cultured hepatoma cells used as a model for hyaline formation in vitro. Our results suggest that disorganization and accumulation of intermediate filaments is an important step in the pathogenesis of alcoholic liver injury. [ABSTRACT FROM AUTHOR]

Human malignant mesotheliomas were studied by electron microscopy. Three main types of cells were seen-submesothelial epithelioid cells, epithelial lining cells and fibroblast-like cells. In submesothelial epithelioid cells prominent arrays of intermediate (10 nm) filaments were often seen attached to plasma membrane, mitochondria, nuclei and concentric whorls of rough endoplasmic reticulum. The other types of cell found in the tumors, epithelial lining cells and fibroblast-like cells, lacked such distinct filaments. The intermediate filaments were especially abundant in cells with extensive whorling of endoplasmic reticulum. The association of intermediate filaments with such deranged cytoplasmic organization suggests that they play a role in the altered behavior of malignant cells. [ABSTRACT FROM AUTHOR]

Extracellular matrix (ECM) proteins are known to play a role in inflammatory and hyperplastic processes. Our aim in the present study was to study the distribution of tenascin (Tn), cellular fibronectins (cFn) and myofibroblasts around biodegradable poly-L/D-lactide (PLA) implants with monoclonal antibodies (MAb). Ethylene-oxide and gamma-irradiation sterilized PLA plate-type implants were inserted into the dorsal subcutaneous tissue of ten adult rabbits. Follow-up times were 4, 12, 16, 36 and 48 wk. Only some inflammatory cells were observed. In electron microscopy, a close coherence between the implant and the stromal tissue was seen. Immunoreactivity for Tn, cFn and α-actin was detected as a distinct layer bordering the implant, regardless of the sterilization method for the first 36 wk. From week 36 onwards, Tn immunoreactivity was downregulated while cFn immunoreactivity still persisted. A moderate upregulation for myofibroblasts was seen on the week 48 specimens, when hydrolysation of PLA implant had started. The persistent content of myofibroblasts, Tn and cFn suggests a prolonged wound healing produced by PLA implants. The absence of Tn at the week 48 specimens suggests that cFn, rather than Tn may be needed for α-actin-mediated contraction by myofibroblasts. [ABSTRACT FROM AUTHOR]

In previous studies poly (ortho ester) (POE) has shown promise as a resorbable device, a hemostatic sealant and as a carrier for drugs in bone surgery. The aim of this study was to evaluate the tissue reactions of solid poly (ortho ester) implanted into both tibiae of 17 rabbits. One half of the rods were sterilized by gamma radiation and the other half by ethylene oxide. The follow-up times were from 1 week to 21 weeks, after which the animals were killed and the bony specimens examined histologically. The connective tissue samples were examined immunohistochemically in order to study the occurrences of two extracellular matrix glycoproteins, tenascin and fibronectin. The results showed that solid poly (ortho ester)s induce a moderate inflammatory reaction for 9 weeks. Tenascin and fibronectin were present in samples from 1 week up to 4 weeks. It was also found that gamma sterilized POE was resorbed at week 7 and ethylene oxide sterilized POE at week 13. [ABSTRACT FROM AUTHOR]

The intracellular transport of the HSV-1 glycoproteins gA/gB, gC and gD has been followed by the indirect immunofluorescence technique (IIF). Infected tissue culture cells were stained with monoclonal antibodies made to the individual glycoproteins and with fluorochrome-coupled wheat germ agglutinin reacting specifically with Golgi apparatus of the cells. Staining of either infected, human fibroblasts or of VERO cells at 9 hours p.i. with antibodies to gA/gB showed a prominent ring-like nuclear fluorescence and distinct staining of the Golgi apparatus in the cells. Antibodies to gC and gD stained mainly the Golgi apparatus and areas close to or at the surface of the cells. By immunocytolysis of HSV-1-infected VERO cells the viral glycoproteins were demonstrable at the surface of cells but growth of infected cells in the presence of either TM or monensin inhibited the expression of most of the viral glycoproteins at the cell surface. Blocking of the glycosylation of the viral glycoproteins with tunicamycin (TM) was followed by accumulation of the core of the glycoproteins gA/gB and gD in granular structures close to the nucleus as seen by immunofluorescence microscopy. Antibodies to gC did also stain granules close to the nucleus but in addition the periphery of the cells were stained. Inhibition of intracellular transport from the Golgi apparatus by the carboxylic ionophore monensin was followed by accumulation of all the HSV-1 glycoproteins in vesicles derived from the Golgi apparatus in both human fibroblasts and VERO cells. Our data thus support the hypothesis that the HSV-1 glycoproteins are processed in the Golgi apparatus before the transport to and incorporation into the cell surface membrane of infected cells and into virion envelopes. [ABSTRACT FROM AUTHOR]

Fluorochrome-coupled Helix pomatia agglutinin (HPA), but not other lectin-conjugates with the same nominal specificity, bound specifically to the Golgi apparatus in cultured human fibroblasts, revealing a cytoplasmic juxtanuclear reticular structure. Unlike other Golgi-binding lectins the HPA-conjugates did not bind to the cell surface membrane or pericellular matrix. Experiments with S-methionine-labeled cells showed that HPA recognized two glycoproteins of M 170000 and 400000 among the secreted products of fibroblasts and two major cellular glycoproteins of M 40000 and M 180000 in Triton X-100 extracts of the cells. The two cellular HPA-binding polypeptides were also found in cells depleted of secretory products and in cells pulselabeled shortly with S-methionine and then chased with methionine containing medium up to 12 h. These findings suggest that the two cellular glycoproteins recognized by HPA are retained in the Golgi apparatus and are therefore not precursors of secretory proteins. The results suggest that there are two endogenous, Golgi apparatus-specific glycoproteins in cultured human fibroblasts with terminal non-reducing O-glycosidic N-acetyl galactosaminyl residues. [ABSTRACT FROM AUTHOR]

Binding of N-acetyl galactosamine (GalNAc)-specific Dolichos biflorus agglutinin (DBA) conjugates to frozen sections of normal epidermis and of psoriatic uninvolved and lesional skin was studied in fluorescence microscopy. The DBA conjugates bound only to single basal cell layer in normal and uninvolved psoriatic epidermis from patients with different blood group status. In the lesional area of psoriatic skin a similar reaction with a single basal cell layer was revealed. Other lectin-conjugates applied, presenting also GalNAc specificity, reacted with most cell layers of normal and both uninvolved and lesional psoriatic epidermis and gave an attenuated reaction with the middle epidermal layers. The results show that the basal cell characteristics are confined only to the cells along the basal membrane also in psoriatic epidermis, although cells in three lowest layers may be able to proliferate. [ABSTRACT FROM AUTHOR]

The distribution of the extra domain-containing form of cellular fibronectin was studied in human placentas at different stages of maturation by using the monoclonal antibody 52DHl in indirect immunofluorescence. In early chorionic tissue (7 to 10 weeks post menstruationem) cellular fibronectin was codistributed with laminin and type IV collagen in the trophoblastic basement membranes. At weeks 11 to 12 the trophoblastic basement membranes were negative but positivity was typically revealed in distinct aggregates in the stromal tissue. In second-trimester and term placentas the immunoreactivity was confined to the vessel endothelia of villous stroma. Extravillous trophoblast cells seen in placentas at different stages did not show positivity. Double staining with the 52DHl monoclonal antibody and polyclonal fibronectin antibodies showed that both in the early and term placentas there was much fibrillar positivity only revealed with the polyclonal antibodies. The present results show that cellular fibronectin is a prominent component of early trophoblastic basement membranes and may thus play a special role in the maturation of chorionic villi. [ABSTRACT FROM AUTHOR]

In 3-and 12-hour-old pollen tubes of Nicotiana tabacum microtubules (MTs) most resistant to cold-depolymerization were located in the generative cell (GC). The most cold-sensitive MTs occurred in the apical region of the pollen tube. In the basal part of the tube, the cold-resistance of MTs increased, especially in 12-hour-old tubes. The cold depolymerization pattern of MTs with accumulation of tubulin at the cell and nuclear membranes suggested that binding of MTs to membranes might increase their stability. The IIF microscopy and staining with fluorochrome-conjugated phallotoxins indicated that microfilaments (MFs) unlike MTs remained polymerized in cold-treated pollen tubes. Recording of the positions of the vegetative nucleus (VN) and GC in the control and cold-treated pollen tubes in different ages showed clearly that low temperature stopped sharply the movement of the VN and GC into the young tubes while no drastic effects were recorded in the old tubes. The cessation and recovery of the movement correlated well with de-and reassembly of MTs, which indicated that MTs in addition to MFs may be necessary for the movement of VN and GC. The immunoblot results showed that the levels of tubulin and actin monomers in the cold-treated tubes were comparable to those present in the control tubes, which might be a prerequisite for the rapid recovery of the structure and function of the cytoskeleton recorded after the return of the cold-treated pollen tubes to normal temperature. [ABSTRACT FROM AUTHOR]

Vestibular neurons from adult rats were studied by immunofluorescence microscopy using ten polyclonal and monoclonal antibodies reacting with different subunits of neurofilament (NF) polypeptides. Most antibodies strongly immunolabeled axons and dendrites. With the majority of antibodies the vestibular ganglion cells showed two distinct subpopulations: those with intense immunoreactivity and those without it. The intensely immunoreactive somata, staining with anti-70 kDa and anti-200 kDa NF antibodies but not with anti-150 kDa NF antibodies, comprised 32% of the ganglion cells (range: 27-40%). These cells were larger than the weakly immunoreactive majority of cells. Comparisons of adjacent sections revealed that at least a part of the distinctly immunostained cells were the same regardless of the antibody used. Thus, about one-third of the vestibular ganglion cells seem to form a subpopulation containing 200 kDa and 70 kDa subunits of NF polypeptides. Similar compositions of NF subunits have been demonstrated in such cells as the large dorsal root ganglion cells. The high percentage of neuronal somata with phosporylated subunits of NF polypeptides demonstrated in this study is exceptional in other normal neurons and has been demonstrated only in experimental models and disease states. [ABSTRACT FROM AUTHOR]

In the adult human cochlea, a cytokeratin (Ck) network exists along the entire surface of the organ of Corti, enclosing it like a shell. Only the surfaces of the outer and inner hair cells are not integrated in this network. In temporal bone specimens, Ck filaments in Hensen's cells were found to be arranged parallel with and closely apposed to the plasma membrane. In the stria vascularis, Cks were identified only in the marginal cells. Cells in Reissner's membrane and spiral prominence showed varying degrees of immunoreactivity to different monoclonal antibodies directed against Cks. A distinct positivity for Cks was found in most spiral ganglion cells, indicating their presence in all cells. The principal pattern of immunoreactivity was the same in the organ of Corti of the entire cochlea. However, a quantitative gradient in the expression of Cks was observed, with more Cks at the apex than at the base. This was correlated to a difference in the number of Hensen's cells between the two regions. The distinct shell configuration of the Ck network in Corti's organ gives it a tonotopically related difference in rigidity which must be of considerable importance for the perception of sound in the cochlea. The absence of Cks in inner and outer sulcus cells gives them cytoskeletal characteristics of mesenchymal cells with a possible regenerative potential. [ABSTRACT FROM AUTHOR]

The glomeruli of a normal and a hydronephrotic kidney were studied in scanning electron microscopy. In the glomeruli of the normal kidney the interdigitating terminal processes of the podocytes were clearly seen and they seemed to originate from different cells. The glomeruli of the hydronephrotic kidney were often surrounded by an enlarged Bowman's space but their overall structure was preserved. The podocytes were, however, irregularly thickened and the terminal processes had disappeared with the swelling of the major cytoplasmic processes. [ABSTRACT FROM AUTHOR]

Carcinoid tumor of the colon was studied in electron microscope. In cytoplasm, prominent intermediate-sized filaments were seen frequently attaching to nucleus and mitochondria. Direct contacts of intermediate filaments with secretory granules were not observed. [ABSTRACT FROM AUTHOR]