Enzymatically degraded LDL preferentially binds to CD14(high) CD16(+) monocytes and induces foam cell formation mediated only in part by the class B scavenger-receptor CD36.

Heterogeneity of peripheral blood monocytes is characterized by specific patterns in the membrane expression of Fc gamma-receptor III (FcgammaRIII/CD16) and the lipopolysaccharide receptor (LPS receptor CD14), allowing discrimination of distinct subpopulations. The aim was to analyze the correlation of these phenotypic differences to the early interaction of freshly isolated monocytes with modified lipoproteins by the use of either enzymatically degraded low density lipoprotein (E-LDL), acetylated low density lipoprotein (ac-LDL), oxidized low density lipoprotein (ox-LDL), or native low density lipoprotein. Highest E-LDL binding was observed on CD14(high) CD16(+) monocytes as determined by flow cytometry, suggesting a selective interaction of E-LDL with distinct subpopulations of monocytes. E-LDL induced rapid foam cell formation both in predifferentiated monocyte-derived macrophages and, in contrast to ac-LDL or ox-LDL, also in freshly isolated peripheral blood monocytes. This was accompanied by upregulation of the 2 class B scavenger receptors CLA-1/SR-BI (CD36 and LIMPII Analogous-1/scavenger receptor type B class I) and CD36. Cellular binding and uptake of E-LDL was neither competed by ac-LDL nor the class A scavenger-receptor inhibitor polyinosinic acid but was partially inhibited by an excess of ox-LDL. In predifferentiated monocyte-derived macrophages, an anti-CD36 antibody inhibited cellular binding and uptake of E-LDL by approximately 20%, suggesting that recognition of these hydrolase-modified low density lipoprotein particles is mediated only in part by the class B scavenger receptor CD36.

C-reactive protein in the arterial intima: role of C-reactive protein receptor-dependent monocyte recruitment in atherogenesis.

Infiltration of monocytes into the arterial wall is an early cellular event in atherogenesis. Recent evidence shows that C-reactive protein (CRP) is deposited in the arterial intima at sites of atherogenesis. In this study, we demonstrate that CRP deposition precedes the appearance of monocytes in early atherosclerotic lesions. CRP is chemotactic for freshly isolated human blood monocytes. A specific CRP receptor is demonstrated on monocytes in vitro as well as in vivo, and blockage of the receptor by use of a monoclonal anti-receptor antibody completely abolishes CRP-induced chemotaxis. CRP may play a major role in the recruitment of monocytes during atherogenesis.

[35-year-old patient with metastasized carcinoid of Vater's ampulla--case report and review of the literature]. / 35jährige Patientin mit einem metastasierten Karzinoid der Papilla Vateri--Fallbericht und Literaturübersicht.

We report the case of a 35-year-old female patient with a metastasized carcinoid of the papilla of Vater which is a rare lesion. 96 cases have been published in world literature previously. The carcinoid of the papilla of Vater appears typically as a hormone inactive tumor. It becomes symptomatic by cholestasis and jaundice in most cases and not by carcinoid-syndrome. An association with von Recklinghausen's disease as described in 25% of cases was not given in our patient. In contrast to the duodenal carcinoid there is no linear relationship between primary tumor size and incidence of metastases. The correct diagnosis was proven by histologic and immunohistochemical methods on specimen taken after endoscopic papillotomy. In spite of sensitive diagnostic methods like endosonography and somatostatin-receptor-scintigraphy exact staging was made intraoperatively in this case. Three months after pylorus pancreatoduodenal resection with lymphadenectomy the patient remained well with no evidence of tumor recurrence.

Complement and atherogenesis: binding of CRP to degraded, nonoxidized LDL enhances complement activation.

Complement activation occurs in temporal correlation with the subendothelial deposition of LDL during early atherogenesis, and complement also plays a pathogenetic role in promoting lesion progression. Two lesion components have been identified that may be responsible for complement activation. First, enzymatic degradation of LDL generates a derivative that can spontaneously activate complement, and enzymatically degraded LDL (E-LDL) has been detected in the lesions. Second, C-reactive protein (CRP) colocalizes with complement C5b-9, as evidenced by immunohistological studies of early atherosclerotic lesions, so the possibility exists that this acute phase protein also fulfills a complement-activating function. Here, we report that addition of LDL and CRP to human serum did not result in significant C3 turnover. Addition of E-LDL provoked complement activation, which was markedly enhanced by CRP. Binding of CRP to E-LDL was demonstrated by sucrose flotation experiments. Binding was Ca(2+)-dependent and inhibitable by phosphorylcholine, and the complement-activating property of E-LDL was destroyed by treatment with phospholipase C. These results indicated that CRP binds to phosphorylcholine groups that become exposed in enzymatically degraded LDL particles. Immunohistological studies complemented these findings in showing that CRP colocalizes with E-LDL in early human atherosclerotic lesions. Thus enzymatic, nonoxidative modification of tissue-deposited LDL can be expected to confer CRP-binding capacity onto the molecule. The ensuing enhancement of complement activation may be relevant to the development and progression of the atherosclerotic lesion.

C-reactive protein frequently colocalizes with the terminal complement complex in the intima of early atherosclerotic lesions of human coronary arteries.

There is increasing evidence that complement activation may play a role in atherogenesis. Complement proteins have been demonstrated to be present in early atherosclerotic lesions of animals and humans, and cholesterol-induced atherosclerotic lesion formation is reduced in complement-deficient animals. Potential complement activators in atherosclerotic lesions are now a subject matter of debate. C-reactive protein (CRP) is an acute-phase protein that is involved in inflammatory processes in numerous ways. It binds to lipoproteins and activates the complement system via the classic pathway. In this study we have investigated early atherosclerotic lesions of human coronary arteries by means of immunohistochemical staining. We demonstrate here that CRP deposits in the arterial wall in early atherosclerotic lesions with 2 predominant manifestations. First, there is a diffuse rather than a focal deposition in the deep fibroelastic layer and in the fibromuscular layer of the intima adjacent to the media. In this location, CRP frequently colocalizes with the terminal complement complex. Second, the majority of foam cells below the endothelium show positive staining for CRP. In this location, no colocalization with the terminal complement proteins can be observed. Our data suggest that CRP may promote atherosclerotic lesion formation by activating the complement system and being involved in foam cell formation.

Expression of Bcl-X(L), an antiapoptotic member of the Bcl-2 family, in esophageal squamous cell carcinoma.

Bcl-X, a Bcl-2-related protein, is a potent antagonist of apoptosis in its long splice variant (Bcl-X(L)). The present study was performed to determine its expression in preneoplastic and neoplastic lesions of the esophagus, its correlation with other members of the Bcl-2 family, and its impact on the outcome of surgically treated esophageal cancer patients. Samples of normal esophageal squamous epithelium (n = 10), severe squamous cell dysplasias (n = 19), carcinomas in situ (n = 14), invasive squamous cell carcinomas (n = 172), and lymph node metastases (n = 21) were immunohistochemically analyzed for Bcl-X(L) expression using a polyclonal anti-Bcl-X(L) antibody. The immunostaining was evaluated according to a score system (0-12 points) based on the percentage of positive tumor cells and the relative immunostaining intensity. Cytoplasmic staining for Bcl-X(L) protein was invariably found in all cell layers of the normal esophageal squamous epithelium. In contrast, a considerable portion of preneoplastic and neoplastic lesions display a decreased Bcl-X(L) expression as compared with that in the normal esophageal epithelium. On comparison of the amount of Bcl-X(L) expression between the different types of lesions, however, no significant differences were found between severe squamous cell dysplasias (mean immunoreactive score +/- SD, 5.2 +/- 1.8), carcinomas in situ (5.2 +/- 2.2), invasive carcinomas (4.5 +/- 2.8), and lymph node metastases (4.2 +/- 2.6). In invasive carcinomas, Bcl-X(L) expression decreased continuously with decreasing tumor differentiation (P = 0.0001) and was also directly correlated with bcl-2-associated X protein expression (P = 0.0001). On the contrary, an inverse correlation was found between Bcl-X(L) expression and Bcl-2 protein expression (P = 0.0001). No correlation was found between Bcl-X(L) expression and the parameters pT category, pN category, and tumor size. In the univariate survival analysis, patients with low immunoreactive scores (< or = 4) of Bcl-X(L) expression in the tumor tissue showed lower 2-year and 5-year survival rates than patients with high immunoreactive scores (> 4; P = 0.0485). In multivariate survival analysis, however, only the parameters pN category and pT category, but not Bcl-X(L) expression, could be verified as independent prognostic factors. This tendency of decreasing levels of an antiapoptotic protein toward unfavorable outcome is supported by an increasing number of studies on the role of Bcl-2, another antiapoptotic protein, and must be interpreted against the backdrop of apoptosis as a result of the interaction of many cell death-promoting and protecting proteins.

Immunohistochemical demonstration of enzymatically modified human LDL and its colocalization with the terminal complement complex in the early atherosclerotic lesion.

Treatment of low density lipoprotein (LDL) with degrading enzymes transforms the molecule to a moiety that is micromorphologically indistinguishable from lipoproteinaceous particles that are present in atherosclerotic plaques, and enzymatically modified LDL (E-LDL), but not oxidized LDL (ox-LDL), spontaneously activates the alternative complement pathway, as do lesion lipoprotein derivatives. Furthermore, because E-LDL is a potent inducer of macrophage foam cell formation, we propose that enzymatic degradation may be the key process that renders LDL atherogenic. In this article, we report the production of two murine monoclonal antibodies recognizing cryptic epitopes in human apolipoprotein B that become exposed after enzymatic attack on LDL. One antibody reacted with LDL after single treatment with trypsin, whereas recognition by the second antibody required combined treatment of LDL with trypsin and cholesterol esterase. In ELISAs, both antibodies reacted with E-LDL produced in vitro and with lesion complement activator derived from human atherosclerotic plaques, but they were unreactive with native LDL or ox-LDL. The antibodies stained E-LDL, but not native LDL or ox-LDL, that had been artificially injected into arterial vessel walls. With the use of these antibodies, we have demonstrated that early human atherosclerotic coronary lesions obtained at autopsy as well as lesions examined in freshly explanted hearts always contain extensive extracellular deposits of E-LDL. Terminal complement complexes, detected with a monoclonal antibody specific for a C5b-9 neoepitope, colocalized with E-LDL within the intima, which is compatible with the proposal that subendothelially deposited LDL is enzymatically transformed to a complement activator at the earliest stages in lesion development.

Immunohistochemical colocalization of the terminal complex of human complement and smooth muscle cell alpha-actin in early atherosclerotic lesions.

There is substantial evidence that activated components of the complement cascade are present in atherosclerotic lesions, and it was suggested some years ago that smooth muscle cells may be an important target of complement attack by the terminal components of the cascade, C5b-9, also called the membrane attack complex. Recent in vitro studies have shown that assembly of membrane attack complex on smooth muscle cells leads to the release of monocyte chemotactic protein-1, and, if this were to occur in vivo, then it could be responsible for the recruitment of monocytes into the lesion. In this study we have investigated the localization of C5b-9 in early atherosclerotic lesions of human coronary arteries, collected from autopsies, by immunohistochemical staining, C5b-9 was found to colocalize widely with smooth muscle cell alpha-actin, but not with intact macrophages, thus supporting the hypothesis that interaction of complement with smooth muscle cells may indeed be important in atherogenesis.

Prognostic significance of urokinase-type plasminogen activator expression in squamous cell carcinomas of the esophagus.

In the present study, urokinase-type plasminogen activator (uPA) expression in 150 potentially curatively resected SCCs of the esophagus was analyzed immunohistochemically by means of a murine monoclonal antibody (American Diagnostica, Greenwich, CT) and correlated with survival. Altogether, 122 of the 150 tumors (81.3%) expressed different levels of uPA. Among the 122 uPA-positive tumors, 104 (85.2%) showed a weak staining intensity, and 18 (14.8%) showed a strong staining intensity. Among the uPA-positive tumors, 29 (23. 8%) tumors showed a uPA immunoreactivity in 6-25% of all tumor cells, 30 (24.6%) showed a uPA immunoreactivity in 26-50% of all tumor cells, 41 (33.6%) showed a uPA immunoreactivity in 51-75% of all tumor cells, and 22 (18.0%) showed a uPA immunoreactivity in 76-100% of all tumor cells. No significant correlation could be shown between the different patterns of uPA expression and various clinicopathological parameters, such as pT category, pN category, tumor size, histological grade, blood vessel invasion, lymphatic vessel invasion, and inflammatory response. Concerning the overall postoperative survival, no significant differences between uPA-positive and uPA-negative tumors could be verified. This also held true when different cut points in the percentage of uPA-positive tumor cells were used. In contrast, the intensity of uPA staining provided significant prognostic information in that patients with strongly uPA-positive tumors had a poorer outcome than patients with weakly uPA-positive or uPA-negative tumors. Moreover, as shown by stepwise multivariate Cox regression analysis, the intensity of uPA expression was an independent prognostic factor.

The prognostic significance of epidermal growth factor receptor expression in squamous cell carcinomas of the oesophagus.

EGFR expression in 150 potentially curative resected squamous cell carcinomas of the oesophagus was analyzed immunohistochemically and correlated with survival. Altogether, 124 of 150 (82.7%) tumours expressed different levels of EGFR. The percentage of tumour cells expressing EGFR varied greatly between the different tumours (median: 70%). 62 (50.0%) tumours showed weak and intense staining, respectively. Regarding the staining pattern 19 (15.3%) tumours showed exclusively membraneous immunoreactivity, 27 (21.8%) an exclusively cytoplasmic immunoreactivity and 78 (62.9%) a mixed staining pattern. No significant correlation however could be found between EGFR expression and various clinicopathologic parameters such as pT category, pN category, tumour size, histologic grade and blood vessel invasion. In univariate survival analysis, no correlation between EGFR expression and postoperative survival time was observed. In a forward multivariate Cox regression analysis only the parameters lymphatic-vessel invasion (p = 0.001), pT category (p = 0.0034) and pN category (p = 0.0256), but not the EGFR expression, could be verified as independent prognostic variables. In conclusion, the evaluation of the EGFR expression does not provide prognostic information for patients who underwent potentially curative resection for SCC of the oesophagus.

The prognostic significance of tumour cell proliferation in squamous cell carcinomas of the oesophagus.

Tumour samples from 150 patients with squamous cell carcinoma of the oesophagus were investigated immunohistochemically with the monoclonal antibody MIB-1, which recognises proliferating cells. Using light microscopy, the number of MIB-1-positive tumour cells was counted in the areas with the highest proliferative activity. The MIB-1 index was determined as the proportion of MIB-1-positive and MIB-1-negative tumour cells. A considerable variation of the MIB-1 indices was found between the different tumours with a minimum of 6% and a maximum of 95% (median, 33%). The MIB-1 index correlated significantly with the mitotic activity in the tumour tissue (r = 0.33; P = 0.0001) and with the proportion of apoptotic tumour cells (r = 0.25; P = 0.0017). No significant correlation was found between the MIB-1 index and various other prognostic parameters including pT classification, pN classification, tumour grade, blood vessel invasion and lymphatic vessel invasion. In the univariate survival analysis no significant difference was found between tumours with low (< or = 33%) and high MIB-1 index (> 33%) 5-year survival rate: low MIB-1 index, 19.2%; high MIB-1 index, 22.2%). In a Cox proportional hazard regression analysis only the parameters lymphatic vessel invasion (P = 0.0001), pT classification (P = 0.0034) and pN classification (P = 0.0256), but not the MIB-1 index, could be verified as independent prognostic variables. In conclusion, evaluation of the MIB-1 index does not provide prognostic information for oesophageal cancer patients.

[Comparison of lard-tallow mixture and bone fat in digestion and growth experiments in calves]. / Vergleich von Schmalz-Talg-Gemisch und Knochenfett im Verdauungs- und Wachstumsversuch mit Kälbern.

Male calves between 15 and 26 days old and with a live weight between 45 and 46 kg received dried skim milk dissolved in water plus fat concentration from lard--suet mixtures made with a synthetic emulsifier of the type ethoxylated partial ester with and without soybean lecithin supplement. One group received bone fat with an emulsifier as sole fat component. In the course of 9 experiment weeks the calves of the lard--suet group without lecithin reached an average daily weight gain of 710 g, which was not significantly better than the gains of 689 g of the lard--suet group with lecithin and of 674 g of the bone fat group. The calves of the lard--suet group with lecithin did not digest the feed fat significantly better than the calves in the other two groups. The quota of fatty acids in the feed distinctly influenced the composition of the fatty acids in the intestines, the kidneys and the hypodermis. With the example of suet the general relationship between the fatty acid patterns of the feed and body fats are recognizable, with the fatty acids C 16:0, C 18:2 and C 18:3 having a lower and C 16:1, C 18:0 and C 18:1 having a higher quota in the suet than in the feed fat. Due to the application of high amounts of bone fat, vegetable oil or sea animal fat there are deviations from this rule. There is a higher quota of linolenic acid in the suet of the calves than in butter fat but a lower quota than in foreign fat.