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Biomedical subjects

R Moll

Publications and source records attributed to R Moll.

At least 55 records · Page 3Linked to original sources

Sonography for selecting candidates for laparoscopic cholecystectomy: a prospective study.

OBJECTIVE: We assessed the value of sonography in predicting intraoperative difficulties for patients undergoing laparoscopic cholecystectomy and in identifying indicators for conversion to conventional cholecystectomy. SUBJECTS AND METHODS: Upper abdominal sonography was performed (according to a checklist) in 75 consecutive patients before laparoscopic cholecystectomy. Sonographic findings were verified by the surgeon in the operating room. RESULTS: Conversion from laparoscopic surgery to laparotomy was performed in five patients (6.7%). Of 75 patients, 19 had sonograms revealing gallbladder wall thickening (>4 mm); surgical preparation difficulties in 16 of these patients led to laparotomy in four patients. Sensitivity, specificity, positive predictive value, and accuracy of wall thickening as an indicator of technical difficulties were 66.7%, 94.1%, 84.2%, and 85.3%, respectively. Sensitivity, specificity, positive predictive value, and accuracy of wall thickening as an indicator of surgical conversion were 80.0%, 78.6%, 21.1%, and 78.7%, respectively. Technical difficulties at laparoscopy occurred in all five patients with pericholecystic fluid on sonography (sensitivity, 20.8%; specificity, 100%; positive predictive value, 100%; accuracy, 74.7%) and led to laparotomy in three patients (sensitivity 60.0%, specificity 97.1%, positive predictive value 60%, accuracy 94.7%). The accuracy of sonography for cholecystolithiasis was 100%. CONCLUSION: On sonography, gallbladder wall thickening is the most sensitive indicator and pericholecystic fluid is the most specific indicator of technical difficulties during laparoscopic cholecystectomy. Such difficulties may require conversion to laparotomy.

Abdomen↗

Opacification of the urinary tract in portal venous spiral CT without delayed scans.

In portal venous spiral CT there is no visible renal contrast excretion within the usual period of scanning. To opacify collecting systems additional delayed scanning is required. We administered an extra pre-dose of contrast medium before the main portal venous bolus in order to opacify the urinary tract and studied its effects on liver attenuation. In 32 patients examined first by non-contrast spiral CT 20 ml of a non-ionic IV CM were injected. Five minutes later, orientating cuts in the liver and along the urinary tract were obtained. Immediately thereafter, a 120-ml bolus was administered at 3 ml/s for portal venous phase helical CT (60-s delay craniocaudad). The quality of renal excretion was graded visually (excellent, fair, poor, none). Hepatic attenuation measurements were performed at comparable regions of interest. In all patients 20 ml CM opacified the renal pelvis after 5 min. Depiction of the ureters was excellent in 14, fair in 11 and poor or none in 7 cases. There was little effect on mean hepatic attenuation by the 20-ml pre-bolus after 5 min: mean enhancement 2.3 HU (range -0.6 to 7.8 HU). Mean hepatic enhancement after the 120-ml portal venous bolus ranged between 23.6 and 74.1 HU (mean 51.5 HU). When opacification of the urinary tract is necessary, pre-administration of a 20-ml bolus 5 min before portal venous scanning may save an extra delayed spiral. The effects on hepatic enhancement are negligible.

Contrast Media↗

Forms of epithelial differentiation of draining sinus in acne inversa (hidradenitis suppurativa).

The draining sinus is a late complication of several forms of severe acne, leading to extensive, periodically inflamed lesions that are undermined by a system of fistulas, supposed to be of follicular origin. We investigated the expression of various cytokeratins (CKs) and desmosomal proteins in the draining sinus of acne inversa (hidradenitis suppurativa) using monoclonal antibodies in immunohistochemistry on paraffin-embedded sections. We were able to define three different phenotypes of stratified squamous epithelia covering the sinus tracts. Type I epithelium was cornifying and characterized by the presence of CK 10, desmogleins 1-3 and desmocollins 1-3 in an epidermis-like pattern. Type II epithelium was non-cornifying, negative for CK 10 and positive for CK 13. It was negative for desmocollin 1 but strongly immunopositive for desmoglein 1 suprabasally and for desmoglein 2 in the basal cells. Type III epithelium was non-cornifying and strongly inflamed. It was marked by the presence of CK 7, CK 19 and desmoglein 2 and the absence of CK 10, desmoglein 1 and desmocollin 1. In both type II and III epithelium, desmoglein 3, desmocollin 2 and desmocollin 3 showed an inverted staining pattern as compared with normal epidermis and type I epithelium. Desmoglein 2 and CK 5/14 always remained restricted to the basal cell layer. Antibodies against CK 6 and CK 13/15/16 were immunopositive in all three phenotypes and CK 17 was predominantly immunolocalized to suprabasal layers of type II and III epithelium. The three phenotypes are characterized as pathological stratified squamous epithelia reflecting the dynamic process of inflammation, proliferation and stratification taking place in acne inversa.

Antibodies, Monoclonal↗

Desmosomal plakophilin 2 as a differentiation marker in normal and malignant tissues.

Plakophilin 2 (PKP2) is a widespread protein which shows a remarkable dual location: On the one hand, it appears as a constitutive karyoplasmic protein and on the other it is a desmosomal plaque component of most, probably all, desmosome-possessing tissues and cell culture lines. Here we report on its desmosomal occurrence as revealed by immunocytochemical results obtained with three PKP2-specific murine monoclonal antibodies (mAbs) PP2-62, PP2-86 and PP2-150. These mAbs detect PKP2 in characteristic desmosomes of most normal cells, including simple and stratified epithelia as well as non-epithelial tissues such as myocardium and lymph node follicles. In addition, however, several normal tissues consistently display a differentiation-related PKP2 distribution, for example an absence of immunostaining in the "keratinizing" local specializations of the thymic epithelial reticulum, i.e. Hassall's corpuscles, and the restriction of PKP2 to the stratum basale of most stratified squamous epithelia, in contrast to its absence in upper strata, which contain PKP1- or PKP3-rich desmosomes instead. Taking advantage of the reactivity of mAb PP2-150 with formalin-fixed, paraffin-embedded material, a series of human carcinomas (n = 37) has also been analyzed. The results suggest that mAbs to PKP2 may serve as markers for the identification and characterization of carcinomas derived from--or corresponding to--simple or complex epithelia. Thus consistent PKP2 immunostaining has been observed in all 18 cases of adenocarcinomas tested, but more variable and heterogeneous staining has been noted in squamous cell carcinomas, depending on the specific tumor type. The potential value of such mAbs for cell typing in normal and embryonic tissues and for detecting cell subpopulations with different degrees of differentiation is discussed with respect to their possible application in tumor diagnosis.

Adult↗

Domain structure, GTP-hydrolyzing activity and 7S RNA binding of Acidianus ambivalens ffh-homologous protein suggest an SRP-like complex in archaea.

In this study we provide, for the first time, experimental evidence that a protein homologous to bacterial Ffh is part of an SRP-like ribonucleoprotein complex in hyperthermophilic archaea. The gene encoding the Ffh homologue in the hyperthermophilic archaeote Acidianus ambivalens has been cloned and sequenced. Recombinant Ffh protein was expressed in E. coli and subjected to biochemical and functional studies. A. ambivalens Ffh encodes a 50.4-kDa protein that is structured by three distinct regions: the N-terminal hydrophilic N-region (N), the GTP/GDP-binding domain (G) and a C-terminal located C-domain (C). The A. ambivalens Ffh sequence shares 44-46% sequence similarity with Ffh of methanogenic archaea, 34-36% similarity with eukaryal SRP54 and 30-34% similarity with bacterial Ffh. A polyclonal antiserum raised against the first two domains of A. ambivalens Ffh reacts specifically with a single protein (apparent molecular mass: 46 kDa, termed p46) present in cytosolic and in plasmamembrane cell fractions of A. ambivalens. Recombinant Ffh has a melting point of tm = 89 degreesC. Its intrinsic GTPase activity obviously depends on neutral pH and low ionic strength with a preference for chloride and acetate salts. Highest rates of GTP hydrolysis have been achieved at 81 degreesC in presence of 0.1-1 mm Mg2+. GTP hydrolysis is significantly inhibited by high glycerol concentrations, and the GTP hydrolysis rate also markedly decreases by addition of detergents. The Km for GTP is 13.7 microm at 70 degreesC and GTP hydrolysis is strongly inhibited by GDP (Ki = 8 microm). A. ambivalens Ffh, which includes an RNA-binding motif in the C-terminal domain, is shown to bind specifically to 7S RNA of the related crenarchaeote Sulfolobus solfataricus. Comparative sequence analysis reveals the presence of typical signal sequences in plasma membrane as well as extracellular proteins of hyperthermophilic crenarchaea which strongly supposes recognition events by an Ffh containing SRP-like particle in these organisms.

Amino Acid Sequence↗

[Studies on significance of sentinel lymphadenectomy in pharyngeal and laryngeal carcinoma].

BACKGROUND: Management of the suspected N0-neck (sonography and CT) in squamous cell carcinoma (SCC) of the head and neck is discussed controversially. The question arises whether the sentinel node (SN) concept as it is performed in different areas of clinical oncology is applicable to ear, nose, and throat medicine. METHODS: Nine male patients with SCC were studied (4 oropharynx, 2 hypopharynx, and 3 larynx) in whom different lymph node status was diagnosed clinically (5 x N0, 2 x N1, 2 x N2c). After intraoperative scintillation probe detection, the histological examination of the SN with neck dissection (ND) specimen followed. RESULTS: In 7 of 9 cases SN detection was successful. In 4 of 5 cases of clinical N0 status, SN, and ND specimens were free of tumor histologically, while in one patient radiolabel-identified SN showed tumor cells in histological examination. In 2 patients with clinical N1 neck, SN, and ND were histologically tumor-free in one patient and contained one single tumor metastasis located in the SN in the other patient. In 2 patients with clinically and histologically proven N2c neck, lymph nodes located in regions II and III showed metastasis including capsular rupture. In both cases no lymph node radioactivity was detectable during the operation. CONCLUSIONS: The results suggest that sentinel lymphonodectomy may be suited for ear, nose, and throat medicine. Before it is applied to clinical practice, further problems must be resolved. These include the short distance between the primary injection side and lymph nodes and the influence of intranodal tumor metastasis on the uptake of the radiolabeled tracer.

Aged↗

[Immunohistochemical detection of cytokeratins in the irradiated mandibular gland of the Wistar rat].

BACKGROUND: Damage to the salivary gland (SG) is a well-known sequela of radiotherapy in humans. In many cases irradiation damage causes xerostomia and problems of speech and swallowing. While the functional restriction and the radiogenic SG tissue damage is well documented using histomorphological, electron microscopic and enzyme histochemical methods, immunohistochemical analyses (IH) of the profile of cytokeratins (CK), epithelial differentiation markers, and their alterations in irradiated glands are rare. METHODS: In 59 mandibular glands of rats, we investigated the distribution of CK by IH. The animals differed in age from 3 months to 2 years and pretreatment status (irradiation versus no irradiation). The IH were performed at selected time points (< 4 months/> or = 4-6 months/> 6 months). RESULTS: The monoclonal antibodies (E3, Ks13.1, NCL5D3, K8.12; against CK 17, CK 13, CK 8 and CK 13/15/16, respectively) identified different epithelial structures in rat SG tissue, including excretory duct cells (ECD), striated duct cells (SD), granular convoluted tubules (GTC), intercalated duct cells (ICD), and myoepithelial cells (MC). As typical results, E3 usually stained the ICD, SD, and ECD moderately to strongly and stained the GTC in trace amounts or slightly. K8.12 staining was restricted to ECD and MC. Differences in immunoreactivity were seen between irradiated and non-irradiated glands, predominantly with stronger staining in the irradiated group. A conspicuous finding was the stronger expression of CK 13 in irradiated ECD, ICD, and SD within a latency period of 4-6 months. A similar finding was demonstrated in ICD, ECD, and SD cells after incubation with CK 17 antibodies. In both instances, the staining profile of irradiated glands did not return to nontreatment levels in the long term after exposure. CONCLUSIONS: Previous irradiation has to be considered when interpreting IH of salivary gland tissue, especially in studies on chronic degenerative diseases of the salivary glands.

Animals↗

[Immunohistochemical detection of extracellular matrix proteins in the irradiated rat submandibular gland].

BACKGROUND: Extracellular matrix proteins (EMP) form the main components of basement membranes (BM) and associated structures. Basement membranes influence tissue structure, exchange of substances, and cell growth and differentiation. While BM changes have been reported in malignant tumors and in inflammatory diseases, systematic studies of BM changes following irradiation are rare. Because functional and histomorphological damage to the salivary glands is a well known sequela of radiotherapy in humans, our goal was to describe possible BM changes using an experimental model and immunohistochemistry (IH). METHODS: In 59 rat mandibular glands we investigated the distribution of EMP by IH. The animals differed in age from 3 months to 2 years and pre-treatment status (irradiation vs no irradiation). The analyses were performed at selected time points after completion of external irradiation (< 4 months [M]/> or = 4-6 M/> 6 M). RESULTS: The polyclonal antibodies (anti-laminin [AL], anti-fibronectin [AF], anti-collagen III [AC-III], anti-collagen IV [AC-IV]) identified components of BM (laminin, collagen IV) and BM-associated structures (fibronectin, collagen III) in glandular tissue, in vascular walls, in nerve tissue, and the interstitial connective tissue. Various EMP were detected in different patterns. AL stained nerve tissue moderately and both different gland tissue structures and vascular walls (without adventitia) slightly, while excretory ducts and blood vessel adventitia were distinctly positive for AF. Fibronectin was also present in the connective tissue stroma. Significant differences were seen between irradiated and nonirradiated glands, often with generally stronger and more extensive staining in the irradiated group. For example most tissue structures showed distinctly increasing immunostaining for AL in positive correlation with increasing latency of irradiation up to 6 months. The age was of minor importance. CONCLUSIONS: Previous irradiation has to be considered when interpreting the EMP profile of salivary gland tissue, especially in studies both on chronic degenerative diseases and tumor differentiation developing in an area that has undergone radiation therapy.

Animals↗

Crystallization and preliminary x-ray diffraction studies on the conserved GTPase domain of the signal recognition particle from Acidianus ambivalens.

The signal recognition particle (SRP) of bacteria consists of only one protein, known as Ffh or the SRP54 homologue, which forms a complex with 4.5S RNA. It also binds to signal peptides and contains a GTPase which displays interesting differences to Ras GTPases. The conserved NG-domain of Ffh from the archaebacterium Acidianus ambivalens was cloned and overexpressed with a C-terminal His tag in Escherichia coli. Crystallization experiments of the native protein as well as of the Thr112Ala mutant, which is deficient in GTP hydrolysis, resulted in crystals suitable for X-ray diffraction. The crystals belong to the orthorhombic space group C222(1), with unit-cell parameters a = 64.5, b = 128.3, c = 72.0 A. At cryogenic temperatures, the crystals diffracted to a resolution limit of 2.8 A using a rotating-anode generator and contain one molecule per asymmetric unit. A native data set has been collected using synchrotron radiation to around 2.0 A resolution. Selenomethionine protein was produced; its crystals diffract in-house to about 2.8 A resolution.

Archaea↗

Helical CT cholangiography for the detection and localization of bile duct leakage.

OBJECTIVE: We describe the use of helical CT cholangiography or helical CT after administration of biliary i.v. contrast material to verify and localize bile duct leakage. CONCLUSION: Helical CT cholangiography revealed bile leaks in seven patients after penetrating trauma or liver or gallbladder surgery and excluded bile leaks in two patients with blunt liver trauma. Endoscopic retrograde cholangiography was performed in only one of seven patients with bile leakage and was avoided in an additional two patients in whom CT cholangiography excluded leakage. The method is a feasible, noninvasive tool for the detection and localization of bile leaks and may help avoid endoscopic retrograde cholangiography.

Adult↗

Differential characteristics of two new tumorigenic cell lines of human breast carcinoma origin.

Permanent human tumor cell lines are an important tool for the study of breast cancer. Two new breast cancer cell lines (BrCa-MZ-01 and BrCa-MZ-02) were isolated from a solid tumor and a pleural effusion, respectively. One cell line was established from a medullary carcinoma, the other from a ductal carcinoma. These cells exhibit ultrastructural and immunohistochemical features of epithelial cells of mammary origin. Intermediate filament and cytokeratin typing showed a clear predominance of the simple-epithelial cytokeratins CK 8, CK 18 and CK 19, although the expression was reduced in comparison to the hormone receptor-positive reference cell lines MCF-7 and ZR-75-1. Both cell lines produced slow-growing tumors after subcutaneous (s.c.) transplantation of 1 x 10(7) viable tumor cells into nude mice. The cell line BrCa-MZ-01 expresses the estrogen and progesterone receptor, whereas the cell line BrCa-MZ-02 remains negative. Both cell lines are positive for secretion of platelet-derived growth factor (PDGF) and transforming growth factor-beta (TGF-beta), whereas interleukin-6 (IL-6) is only secreted by the cell line BrCa-MZ-02.

Aged↗

Optimizing liver contrast in helical liver CT: value of a real-time bolus-triggering technique.

Optimal liver enhancement during portal venous-phase helical CT is crucial in the detection of parenchymal liver lesions. In the prospective study reported here we investigated the effects of a real-time bolus-tracking system on mean and maximal liver enhancement. In 79 patients referred to us for abdominal CT we injected 120 ml of non-ionic contrast (300 mg I/ml) at a rate of 3 ml/s. After a nonintravenous contrast upper abdominal scan a portal venous phase was performed. In 39 patients (mean weight 72.6 +/- 18.7 kg, range 48-139 kg) real-time bolus tracking was performed using the CARE Bolus software (Siemens, Erlangen, Germany). The software performs repetitive low-dose test scans in a preselected region of interest and measures the Hounsfield attenuation and liver enhancement in real-time. After a critical threshold (we selected 31 HU) is surpassed, the software starts diagnostic spiral scanning. Our control consisted of 40 patients weighing 51-100 kg (mean 73.2 +/- 11.1 kg) who were scanned with a fixed, preselected start delay of 80 s. Mean hepatic enhancement was 54.0 +/- 9.9 HU (range 33.3-74 HU) in 37 automatically triggered patients, mean peak hepatic enhancement 64.6 +/- 12.6 HU (range 42.0-91.8 HU). In 2 patients of the study group scanning had to be started manually. In the control group with fixed delay mean enhancement was 48.3 +/- 9.2 HU (range 33.8-71.6 HU) and peak enhancement 55.5 +/- 9.7 HU (range 39.7-81.0 HU). Differences were significant (p < 0.05, Student's t-test). Real-time bolus tracking significantly increased mean hepatic enhancement and may improve portal venous hepatic CT scanning.

Adolescent↗

De novo expression of nonhepatocellular cytokeratins in Mallory body formation.

Mallory bodies (MBs) are eosinophilic cytoplasmic inclusions observed predominantly in alcoholic liver disease. Although linked to disease activity, their pathogenesis is still unclear. Since intermediate filaments (cytokeratins) are major components of MBs, their cytokeratin polypeptide composition was analysed with monospecific antibodies for cytokeratins 7, 8, 14, 18, 19, and 20 by immunohistology. MBs were identified by light microscopy and ubiquitin immunostaining. All MBs were positive for cytokeratins 8 and 18. A significant percentage of the MBs was strongly positive for cytokeratins 19 and/or 20, which are not detectable in hepatocytes of normal liver and, in the case of cytokeratin 20, in hepatocytes of diseases devoid of MBs. MBs were essentially negative for cytokeratins 7 and 14. De novo expression of cytokeratins 19 and 20 was independent of the aetiology, occurring in all MB-associated diseases analysed, and seemed to precede MB formation, since in some hepatocytes a cytoskeletal-type staining pattern for these cytokeratins was present. In hepatocellular carcinomas cytokeratins 19 and 20 were frequently detected, but their cellular distribution was less closely associated with MBs. The ectopic expression of cytokeratins 19 and 20 appears to be related to MB formation and may take part in the derangement of the intermediate filaments during MB formation.

Antibodies, Monoclonal↗

Epidermal adhesion molecules and basement membrane components as target structures of autoimmunity.

Intraepidermal and dermal-epidermal cohesion are of paramount importance for the integrity of the skin. Some constituent molecules of keratinocyte adhesion complexes and basement membrane-associated structures are the targets of antibody-mediated autoimmune reactions that give rise to various (muco-)cutaneous blistering diseases. The current state of our knowledge about these molecules--along with the main clinical, histological, and immunohistochemical features of the corresponding autoimmune diseases and their pathogenetic mechanisms--comprise the subjects surveyed in this review. Among the desmosomal cadherins (desmogleins and desmocollins) that mediate epidermal cell-cell adhesion, it has been demonstrated that desmoglein 1 and desmoglein 3 are the autoantigens of pemphigus foliaceus and pemphigus vulgaris, respectively, both diseases that result in intraepidermal blistering. Further, desmocollin autoantibodies may be involved in IgA pemphigus. Paraneoplastic pemphigus is associated with autoantibodies directed against the desmosomal plaque protein, desmoplakin. Of the constituents of hemidesmosomes, the plaque protein, BP230 (BPAG1), and the collagen-like transmembrane protein, BP180 (BPAG2), are the autoantigens of bullous pemphigoid and pemphigoid gestationis, the manifestations of both of which include subepidermal blistering. Several diseases arise from autoimmune reactions against certain proteins associated with the basement membrane located beneath hemidesmosomes, for example laminin 5 (cicatricial pemphigoid), ladinin (LAD-1; linear IgA disease), uncein, and collagen VII (epidermolysis bullosa acquisita), the last of which is the constituent protein of the anchoring fibrils. Such recent advances in the elucidation of the molecular nature of autoantigens may serve as the basis for the development of novel molecule-based therapeutic strategies.

Basement Membrane↗

Biological and prognostic significance of stratified epithelial cytokeratins in infiltrating ductal breast carcinomas.

The biological significance of the differential expression of cytokeratin (CK) polypeptides in breast carcinomas is unclear. We examined the CK profiles of 101 primary infiltrating ductal breast carcinomas using monoclonal antibodies directed against 11 different CKs and against vimentin. Two major CK phenotypes were distinguished: first, a phenotype expressing only the simple-epithelial CKs 7 (variably), 8, 18 and 19, and secondly, a bimodal phenotype co-expressing significant amounts of one or more of the stratified-epithelial CKs 4, 14 and 17. The vast majority of G1 and G2 carcinomas had the simple-epithelium phenotype, as did a subgroup of G3 carcinomas. Interestingly, the majority (62%) of G3 carcinomas exhibited the bimodal phenotype, with the expression of CKs 4, 14 and 17 being statistically correlated with poor histological differentiation and absence of steroid hormone receptors. The distribution of vimentin only partially overlapped with that of these stratified-epithelial CKs. Prognostic analyses suggested that the presence of CKs 4, 14 and/or 17 was associated with short overall and disease-free survival in subgroups comprising G3, oestrogen-receptor-negative and vimentin-negative tumours. In node-positive tumours the correlation between these CKs and a shorter disease-free interval attained statistical significance (log rank, 0.0096). Thus, abnormal CK profiles in ductal breast carcinomas appear to reflect disturbed regulation of differentiation-related gene expression programmes and may prove to be of clinical value.

Antibodies, Monoclonal↗

A novel type of adhering junction in an epithelioid tumorigenic rat cell culture line.

Two major types of plaque-bearing adhering junctions are commonly distinguished: the actin microfilament-anchoring adhaerens junctions (AJs) and the desmosomes anchoring intermediate-sized filaments (IFs). Both types of junction usually possess the common plaque protein, plakoglobin, whereas the other plaque proteins and the transmembrane cadherins are mutually exclusive. For example, AJs contain E-, N-, or P-cadherin in combination with alpha- and beta-catenin, vinculin and alpha-actinin, whereas in desmosomes, desmogleins and desmocollins are associated with desmoplakin and one or several of the plakophilins (PP1-3). Here we describe a novel type of adhering junction comprising proteins of both AJs and desmosomes and the tight junction (TJ) plaque protein, ZO-1, in a newly established, liver-derived tumorigenic rat cell line (RMEC-1). By immunofluorescence microscopy, cell-cell contacts are characterized by mostly continuous-appearing lines which are usually resolved by electron microscopy as extended arrays of closely spaced small plaque subunits. These plaque-covered regions are positive for plakoglobin, alpha- and beta-catenin, the arm-repeat protein p120, vinculin, desmoplakin and protein ZO-1. They are positive for E-cadherin in cultures early on in passaging, but tend to turn negative for all known cadherins in densely grown cultures. On immunoblotting SDS-PAGE-separated proteins from dense-grown cell monolayers, "pan-cadherin" antibodies have reacted with a band at approximately 140 kDa, identified as N-cadherin by peptide fingerprinting of the immunoprecipitated protein, which for reasons not yet clear is modified or masked in immunolocalization experiments. The exact histological derivation of RMEC-1 cells is not known. However, the observations of several endothelial markers and the fact that all cells are rich in IFs containing vimentin and/or desmin, while only subpopulations also reveal IFs containing CKs 8 and 18, is suggestive of a mesenchymal, probably endothelial origin. We discuss the molecular relationship of this novel type of extended junction with other types of adhering junctions.

Animals↗

Adipophilin is a specific marker of lipid accumulation in diverse cell types and diseases.

We report the human DNA and protein sequence of adipophilin and its association with the surface of lipid droplets. The amino acid sequence of human adipophilin has been determined by using cDNA clones from several tissues and confirmed by the reverse transcription/polymerase chain reaction method and Edman sequencing. The open reading frame of adipophilin encodes a polypeptide with a calculated molecular weight of 48.1 kDa and an isoelectric point of 6.72. By immunofluorescence and electron-microscopic localization with newly raised specific poly- and monoclonal antibodies, we show that this protein is not restricted to adipocytes as previously indicated by studies of the mouse homologous protein, adipose-differentiation-related protein. Adipophilin occurs in a wide range of cultured cell lines, including fibroblasts and endothelial and epithelial cells. In tissues, however, expression of adipophilin is restricted to certain cell types, such as lactating mammary epithelial cells, adrenal cortex cells, Sertoli and Leydig cells of the male reproductive system, and steatosis or fatty change hepatocytes in alcoholic liver cirrhosis. Our results reveal adipophilin as a possible new marker for the identification of specialized differentiated cells containing lipid droplets and for diseases associated with fat-accumulating cells.

Adipocytes↗