Klatskin tumour: meticulous preoperative work-up and resection rate

BACKGROUND

Surgery represents the only potentially curative treatment of hilar cholangiocarcinoma (hilCC). It may be suggested that meticulous preoperative work-up in Asian countries leads to higher resection rates.

METHOD

One hundred and eighty-two patients treated in our department between 1998 and 2008 were included in an analysis based on our prospectively recorded database. Among them, 75 % had a percutaneous transhepatic cholangiography as part of their diagnostic work-up. A total of 160 patients underwent explorative surgery and 123 patients were resected (77 % of patients undergoing exploration, 68 % of all patients).

RESULTS

Ninety-one percent of the patients were diagnosed to have Bismuth III and IV tumours. En-bloc resection of the tumour and the adjacent liver including segment 1 was the standard procedure in 109 of these patients, while hilar resection was performed in 14 patients. Upon tumour resection, hospital mortality was 5.7 %. Five-year survival in patients without surgery or with mere exploration was 0 %, after resection it reached 26 %. Patients with R 1 resection experienced longer survival than patients without resection (p < 0.001). Right and left hemihepatectomies were performed with identical frequency resulting in identical survival. Lymph node involvement proved to be the only significant predictor of prognosis (p = 0.006).

CONCLUSION

Resection should be performed whenever possible since even after palliative resection survival is substantially increased compared to patients without resection. Meticulous preoperative work-up may contribute to a high resection rate in patients with hilCC by providing additional information allowing the surgeon to perform more aggressive approaches.

Expression of E-selectin and vascular cell adhesion molecule-1 in so-called 'negative' appendices: first results to support the pathological diagnosis in borderline cases

BACKGROUND

Since the rate of histologically 'negative' appendices still ranges between 15 and 20%, appendicitis in 'borderline' cases remains a challenging disease. As previously described, cell adhesion molecule expression correlates with different stages of appendicitis. Therefore, it was of interest to determine whether the 'negative' appendix correlated with the absence of E-selectin or vascular cell adhesion molecule-1 (VCAM-1).

METHODS

Nineteen grossly normal appendices from a series of 120 appendectomy specimens from patients with suspected appendicitis were analysed in frozen sections for the expression of E-selectin and VCAM-1. As control, 5 normal appendices were stained.

RESULTS

This study showed a coexpression of E-selectin and VCAM-1 in endothelial cells in early and recurrent appendicitis. In patients with symptoms for less than 6 h, only E-selectin was detected. Cases with fibrosis and luminal obliteration were only positive for VCAM-1. In cases of early appendicitis with symptoms of less than 6 h duration, a discordance between histological and immunohistochemical results was found.

CONCLUSIONS

This report indicates that E-selectin and VCAM-1 expression could be useful parameters in the diagnosis of appendicitis in borderline cases.

[Mast cell-rich aluminium granuloma]

Persistent subcutaneous nodules arise at the injection sites of aluminium hydroxide-absorbed hyposensitization solutions. We present a hitherto unreported phenomenon in aluminium granuloma. Two years after specific immunotherapy, a patient suffered increasingly from urticaria. Besides inflammatory infiltrates surrounding necrotic areas, microscopy of the specimen revealed numerous mast cells surrounding the necrotic tissue areas. The histological phenomenon of increased mast cell populations in aluminium granuloma might reflect the association with urticaria, which is probably more frequent than previously reported.

Methylene blue-aided cholangioscopy in patients with biliary strictures: feasibility and outcome analysis

BACKGROUND AND STUDY AIMS

Chromoendoscopy using methylene blue is employed in the gastrointestinal tract to delineate neoplastic lesions. We tested the value of chromoendoscopy during choledochoscopy for characterization of local inflammation, neoplasias, and other alterations in patients with biliary strictures.

METHODS

Patients with suspected biliary lesions were scheduled for endoscopic retrograde cholangiography with subsequent cholangioscopy. After initial inspection of the bile duct, 15 ml methylene blue (0.1 %) was administered via the working channel of the cholangioscope. Newly appearing circumscribed or unstained lesions were judged according to their macroscopic type and staining features. Methylene-blue-aided diagnosis was compared with either clinical follow-up of the patients or, in some cases, with the results of targeted biopsies.

RESULTS

A total of 55 patients [biliary stenosis/cholestasis of unknown origin (n = 24), stenosis after orthotopic liver transplantation (n = 11), primary sclerosing cholangitis (n = 20)] were included. Methylene blue unmasked subtle mucosal changes and permitted macroscopic characterization of circumscribed lesions. Characteristic surface staining patterns were seen in chronic inflammation, dysplasia, and ischemic-type biliary lesions. Nondysplastic mucosa appeared homogeneously stained, whereas scarred strictures showed a weak uptake of methylene blue.

CONCLUSION

In this prospective feasibility study, methylene-blue-aided cholangioscopy was used for the first time to define different staining patterns of the bile duct. The differences in staining patterns identified normal, dysplastic, and inflamed mucosa of the bile duct, as was proved by follow-up or, in some cases, histology. Whereas homogeneous staining predicted the presence of normal mucosa, absence of staining of circumscribed lesions, or diffused staining of such lesions, represented neoplastic changes or inflammation.

Tacrolimus monotherapy without steroids after liver transplantation--a prospective randomized double-blinded placebo-controlled trial

Early steroid withdrawal after liver transplantation (LT) is desirable in order to reduce steroid side effects. Between February 2000 and August 2004, 110 patients after LT were included in this prospective, randomized, double-blind, placebo-controlled trial. Randomization was performed before LT. In all patients, tacrolimus was used without induction therapy. All patients received methylprednisolon for 14 days, thereafter a double-blinded medication containing either placebo (n = 56) or methylprednisolon (n = 54) for 6 months, which was completely stopped thereafter. End points were patient and graft survival, acute and chronic rejection, and incidence of steroid side effects during the first year after LT. One-year patient survival was 85.7% (placebo) and 88.8% (steroid) (p = 0.572). Twenty-seven (48.2%) and 19 (35.2%) patients experienced acute rejection (placebo versus steroid, respectively; p = 0.116). Two patients in the placebo group but none in the steroid group experienced chronic rejection (p = 0.257). The rates of side effects were (placebo versus steroid, respectively): CMV infection 25% versus 33% (p = 0.336), post-transplant diabetes 30% versus 53% (p = 0.024), hypertension 39% versus 52% (p = 0.248), hypercholesterolemia 10% versus 41% (p = 0.002) and hypertriglyceridemia 32% versus 54% (p = 0.046). In conclusion, early steroid withdrawal after LT is feasible under tacrolimus monotherapy without increased rejection rates and with a lower rate of side effects.

Intraoperative Assessment of Liver Organ Condition by the Procurement Surgeon

Generally the transplanting surgeon accepts or declines the offer of a marginal organ in view of all available information. Hence, in some cases it is the procurement surgeon who decides about the suitability for potential further liver transplantation.

METHODS

From January 1, 2003 to September 30, 2005, a total of 402 organ procurement operations were performed in our region.

RESULTS

Due to infrastructural problems in nine cases intraoperative evaluation of liver biopsies was not achievable in time, and the decision to reject the organs was based on the procurement surgeon's clinical assessment. The main reason for liver rejection was alleged extreme steatosis, (6 of 9) or liver cirrhosis (3 of 9). Surprisingly, postoperative histological examinations only confirmed the clinical impression in one of nine cases.

CONCLUSIONS

The clinical assessment of the explanting surgeon resulted in discarding eight of nine organs, potentially not contributing them to the donor pool of EUROTRANSPLANT. Further research is necessary to examine the accuracy of clinical evaluation of donor livers as well their correlation with histology.

Transarterial Chemoembolization Before Liver Transplantation in 60 Patients With Hepatocellular Carcinoma

Tumor recurrence is a major problem after orthotopic liver transplantation (OLT) in patients with hepatocellular carcinoma (HCC). In 60 patients OLT was performed for HCC after pretreatment by repeated transarterial chemoembolization (TACE). Forty-four recipients exceeded the Milan criteria. Recurrence-free 5-year survival was 65.2% and 5-year freedom from recurrence was 73.2%. During the waiting time, 14 patients experienced minimal change, which did not fulfill the definition of tumor progression according to official oncological criteria. Five-year freedom from recurrence among patients with stable compared with progressive disease was 93.3% versus 28.1%, respectively (P = .0001). A strict TACE pretreatment protocol may select patients with obviously biologically less aggressive tumors, who are suitable for OLT even if the HCC exceeds the commonly accepted listing criteria.

[Massive hemorrhage in a 28-year-old male patient with intestinal Behçet's disease]

A 28-year-old man was admitted to the emergency room of our hospital after syncope and acute gastrointestinal bleeding. On the basis of numerous oral and genital ulcerations as well as uveitis anterior and erythema nodosum, the diagnosis of Behçet's disease had been confirmed previously. The bleeding focus could not be detected by endoscopy. During the next days recurrent massive hemorrhages occurred in spite of immunosuppressive therapy with steroids. Angiography revealed a circumscribed bleeding source in the colon transversum near the left colonic flexure, which was treated by superselective coil embolization. A massive hemorrhage reoccurred and required a surgical approach with a Hartmann procedure. Histology depicted bleeding into the submucosa and mucosa and an ulcer in this area as well as lymphatic infiltration of the mucosa. Immunosuppressive therapy was intensified with azathioprine and resulted in a dramatic improvement of the oral and genital ulcers. In addition, no further gastrointestinal hemorrhage occurred. Due to its higher prevalence in patients from eastern Asia, Behçet's disease poses an important differential diagnosis of intestinal hemorrhage in patients of this descent.

Image cytometric DNA analysis of mucosal biopsies in patients with primary achalasia

AIM: To determine DNA aneuploidy in mucosal biopsies of achalasia patients for subsequent rapid diagnosis.

METHODS: Biopsies from the middle third of the esophagus were obtained in 15 patients with achalasia. Immunohistochemical staining was carried out with monoclonal antibodies MIB-1 for Ki67 and PAb 1801 for p53, in addition to the conventional histologic examination for dysplasia. Nuclei of fresh biopsy material were enzymatically and mechanically isolated, and the DNA content was determined with image cytometry after Feulgen staining. DNA grading of malignancy was assessed according to Boecking to determine the variability of DNA values noted around the normal diploid peak. Further indices measured included the aneuploid rate, and the 5c-, 7c- and 9c-exceeding rate.

RESULTS: The histological examination did not demonstrate dysplasia; while MIB-1 (basal) showed a positive reaction in 8/15 achalasia specimens, p53 was negative in all specimens. Image cytometric DNA analysis detected aneuploidy in 4/15 (26.7%) specimens. Samples from 15 patients with squamous cell carcinoma as well as specimens obtained exclusively 2 cm proximal to the tumor served as reference tests. All carcinomas (15/15) as well as 9 of the peritumoral samples (9/15) were aneuploid. The comparison of biopsies from achalasia patients with peritumoral and carcinoma specimens revealed statistically significant differences regarding the aneuploid rate (diploid: P < 0.0001; tetraploid: P = 0.001), grading of malignancy according to Boecking (P < 0.0001) and the 5c- (P < 0.0001), 7c- (P < 0.0001), and 9c- (P = 0.0001) exceeding rate with progredient DNA alterations in the respective order.

CONCLUSION: The finding that DNA aneuploidy was identified by image cytometry in esophageal specimens of patients with achalasia, which may be due to specific chromosomal alterations presenting as precancerous lesions in 27% of patients, leads us to conclude that image cytometry represents a valuable screening tool.

Mammadiagnostische Zweitbefundung in der Radiologischen Klinik: sinnvoller Mehraufwand oder Ressourcenverschwendung?

PURPOSE

To assess the effect of a second diagnostic reading of breast imaging at a university department of radiology.

MATERIAL AND METHODS

The diagnostic reports of first readers from different private radiology practices and the reports of second readers from the university department of radiology were compared with the histological results (n = 214) and outcome of follow-ups for 4 years (n = 74) in 236 patients (mean age 55 years). BI-RADS categories were used for this purpose. The initial examinations had been performed because of symptoms (n = 117), early detection outside an organized screening program (n = 102), evaluations following breast cancer therapy (n = 13) and unknown primary tumors (n = 4). In addition, the number of complementary examinations and the influence of a second reading on patient management were evaluated.

RESULTS

A total of 140 lesions were malignant and 148 were benign. Of the 288 lesions, 49 % were classified identically in the second reading; 36 % (79/217) of the lesions initially classified as BI-RADS 4 and 5 were downgraded to benign; and 41 % (29/71) of the lesions classified as BI-RADS 1 to 3 were upgraded as suspected of being malignant. The kappa value between the first and second readers was 0.34 with respect to each BI-RADS category separately and 0.18 with respect to categories 1 to 3 (benign) versus 4 and 5 (malignant). A second reading increased the sensitivity from 81 % (114/140) to 96 % (135/140) and the specificity from 30 % (45/148) to 78 % (116/148). Second readers detected 23 additional malignant lesions, changed two lesions correctly classified as malignant to benign categories and caused 6 additional false-positive findings. In all, 38 surgical biopsies could be prevented, one biopsy was erroneously delayed and three unnecessary excisional biopsies were initiated. In the study group, 49 MRI examinations revealed 5 additional malignant lesions and positively influenced surgical planning in 28 patients. In addition to these MRI examinations, 221 patients were examined using ultrasonography, 62 patients using complementary mammography, and 7 using galactography.

CONCLUSION

The benefit of a second reading outweighs the expenditure.

[Diagnostic imaging of hilar cholangiocarcinoma: preoperative evaluation of ERC, MRC and PTC in comparison with histopathology]

PURPOSE

To compare the results of the preoperative workup consisting of endoscopic retrograde cholangiography (ERC), magnetic resonance cholangiography (MRC), and percutaneous resonance cholangiography (PTC) with the tumor extent of the surgical specimen in patients with hilar cholangiocarcinoma (hilCC).

MATERIALS AND METHODS

Between 9/1997 and 12/2002, 59 patients with hilCC tumor underwent surgical resection. Preoperative ERC, MRC, and PTC were analyzed, blinded for the identity of the patient, and compared with the surgical specimen. For this retrospective analysis, 55 of the initial 59 ERCs, 39 of the initial 40 MRCs and 32 of the initial 38 PTCs were available. Most of the ERCs and MRCs had been performed at referring institutions by various investigators. In 20 patients, all three imaging modalities were available for direct comparison.

RESULTS

The mean scores of the visualization of the bile ducts and tumor differ considerably for ERC, MRC and PTC, with PTC visualizing the bile ducts better than ERC (p < 0.001) and MRC (p = 0.019). The tumor classification according to Bismuth and Corlette was correctly predicted by ERC in 29 %, by MRC in 36 % and by PTC in 53 %. The tumor extent was overestimated in 40 % (ERC), 41 % (MRC) and 31 % (PTC) and underestimated in less than 10 % for all modalities. Twenty patients, who underwent all three imaging modalities, were included in an additional analysis for a direct comparison of ERC, MRC and PTC. PTC provided correct or acceptable information on tumor extent in 19 of 20 patients, MRC in 15 of 20 patients, and ERC in only 11 of 20 patients. The statistical analysis revealed a significant superiority of PTC to ERC (McNemar test: p < 0.01) but not to MRC (p = 0.22).

DISCUSSION

The management of patients with hilar cholangiocarcinoma requires a high degree of expertise in diagnostic imaging techniques. Cholangiography should not only define the location but also visualize the uppermost extent of the tumor to determine resectability. In contrast to most reports in the literature, ERC and MRC were found to be of limited reliability regarding the assessment of the tumor extent. ERC may be more and more reserved for patients considered for nonsurgical intervention or palliation. PTC proved to be the most reliable approach. MRC represents a noninvasive diagnostic tool for the evaluation of malignant perihilar biliary obstructions, but should be performed at highest quality using state-of-the-art MRI techniques. The most common mistake of each diagnostic modality was an overestimated tumor extent, which may exclude patients from potentially curative surgery.

Complete gangrene of penis in patient with arterial vascular disease

We present a clinical case of distal penile gangrene in a patient with peripheral vaso-occlusive disease that did not correlate with the extension of the intraoperative finding and required total penectomy. Surgical intervention at the onset of wet gangrene avoids the complication of sepsis.

[Hilar cholangiocarcinoma -- results of en bloc resection of tumor and liver]

The increasingly performed en bloc resection of liver and hilar tumor has contributed to the improvement of long-term survival in patients with hilar cholangiocarcinoma. Based on preoperative definition of operative strategy we tried to avoid any traumatization of the hilar region. Between September 1997 and September 2002, 82 patients with hilar cholangiocarcinoma were treated at our department. Three patients were excluded from any surgery. The resection rate was 75% (59 of 79); 79% (38 of 48) of en bloc resections of the hilar tumor and adjacent liver were formally curative. The hospital mortality was 7%. The 1- and 3-year survival rates of patients after explorative laparotomy, palliative and curative resection was 27 and 7%, 67 and 26%, 89 and 45% ( p<0.001), respectively. The 1- and 3-year survival rates of patients after en bloc resection were 78 and 49%, respectively. In patients with formally curative en bloc resection ( n=38), the 3-year survival rate was 63%; in patients with N0/R0 resection ( n=31) it was 71%. Lymph node involvement proved to be the only independent prognostic marker if patients who underwent hilar and en bloc resection were included in the multivariate analysis. The R situation was the only significant predictor for patients after en bloc resection. These data justify the extended diagnostic work-up and the principal liver resection in hilar cholangiocarcinoma.

Preoperative imaging of hilar cholangiocarcinoma: surgical evaluation of standard practises

It was the goal of this study to compare the results of the preoperative diagnostic workup (ERC, MRC, and PTC) with the tumor extent of the surgical specimen in patients with hilar cholangiocarcinoma (hilCC).

PATIENTS AND METHODS

Between 9/97 and 12/2002 82 patients with hilCC were treated at our institution. In 59 patients tumor resection was feasible. Preoperative ERC, MRC and PTC - blinded for the idendity of the patients - were analysed retrospectively and compared with the surgical specimen.

RESULTS

PTC resulted in significantly superior visualization of the bile ducts including the hilar lesion compared to ERC and MRC (p < 0.01). ERC, MRC and PTC were correct in predicting tumor extent in 29, 36 and 53 % of cases, respectively. The extent of the tumor was overestimated in 42 % (ERC), 41 % (MRC) and 31 % (PTC). Underestimation or wrong assessment or no decision at all occurred in 31, 23 and 16 %, respectively. In 20 patients results of all three diagnostic methods were available allowing a statistical comparison regarding the resection to be performed: PTC was superior to ERC (McNemar test:p < 0.01), but not to MRC. In the patients with overestimated tumor extent both the rate of curative resections and survival were similar to the other resected patients.

DISCUSSION

In contrast to most reports in the literature, ERC and MRC were found to be of limited reliability regarding the assessment of tumor extent. PTC proved to be the most reliable approach. Overestimation of the tumor extent, which may lead to exclude the patient from potentially curative surgery, was the most common mistake in each diagnostic modality.

Expression of KIT (CD117) in biphasic pulmonary blastoma. Novel data on histogenesis

Biphasic pulmonary blastoma (BPB) is a rare primary neoplasm of the lung and its histogenesis is still uncertain. It has been proposed that BPB is derived from mesoderm or endoderm. Others suggested an origin from a single pluripotential cell. We present a case of a BPB with emphasis on expression of the stem cell factor receptor KIT (CD117). We describe a 61-year-old male patient with a BPB of the upper right lobe. Immunohistochemical analysis was performed using a panel of several antibodies including anti-CD117. Strong cytoplasmic expression of CD117 was found in the epithelium (cytokeratin-positive) as well as in the spindle cells (cytokeratin-negative). Expression of CD117 in both mesenchymal and epithelial cells suggests a single origin and supports the idea that BPB arises from a pluripotential cell that can differentiate into both stromal and epithelial morphologies. The role of CD117 in the pathogenesis of BPB and its possible therapeutic relevance require further investigation.

[Endosonographically controlled transluminal fine needle aspiration biopsy: diagnostic quality by cytologic and histopathologic classification]

BACKGROUND AND OBJECTIVE

EUS-guided fine needle aspiration (EUS-FNA) has emerged as a highly accurate technique for detecting and classifying mediastinal and pancreatic lesions as well as abdominal and recently retroperitoneal masses with a minimum of risk for the patient.

PATIENTS AND METHODS

To objectify these statements, we evaluated the quality of 72 EUS-FNA specimens by cytologic and histopathologic classification, investigated their contamination with tissue from the needle pathway and observed puncture-related complications in a retrospective study of 44 EUS-FNA in 41 consecutive patients (56 +/- 14 years, m = 24, f = 17; 13 pancreatic, 9 adrenal, 6 abdominal and 13 mediastinal masses). EUS-FNA was performed using a PENTAX 32 UA endosonoscope (longitudinal 7.5 MHz sector array) in combination with a needle system type "Hancke-Vilmann".

RESULTS

16 vs. 11 of 34 histopathologic and 38 cytologic specimens were classified "excellent", 7 vs. 10 "sufficient", 7 vs. 13 "poor" and 4 vs. 4 "failed". Analysis of contamination with tissue from the needle pathway showed 4 vs. 2 specimens "highly", 3 vs. 14 "clearly", 8 vs. 19 "slightly" and 19 vs. 3 "not" contaminated. Specimens classified "excellent" were less contaminated (p = 0,037). EUS-FNA identified 35 benign and 24 malignant masses. Definite diagnosis failed in 13 specimens. One nonfatal complication occurred. EUS-FNA is an accurate (89 %) and low-risk procedure to examine primary undiagnosed mediastinal, pancreatic, intraabdominal and especially adrenal lesions in most of the cases. Contamination with tissue from the needle pathway seems to be a major predictive factor of poor specimen quality and failed diagnosis.

CONCLUSION

EUS-FNA expands the diagnostic approach of mediastinal, abdominal, pancreatic and adrenal masses and provides accurate specimens for reaching new differential-diagnostic competence, especially in endocrinologic cases.

Chromosomal aberrations in premalignant and malignant squamous epithelium

Biopsies of oropharyngeal cancer were screened for chromosomal imbalances by comparative genomic hybridization (CGH) performed on 22 primary tumors and morphologically nonmalignant surrounding mucosa. The aim was to determine early chromosomal changes of tumor development and to draw conclusions on the mechanisms leading to multiple tumors. The most prominent chromosomal imbalances observed were over representations of genomic material on 3q, 15q, 8q, and 11q and losses on 9p, 3p, and 11q. In morphologically normal mucosa collected at 1 cm from the primary tumor border (M1), amplifications on 15q and 21q were most frequent. Far fewer gains and losses were found in M1 than in the primary tumor (average 2.2 vs. 6.9). Gains dominated over losses, but a tendency toward an increasing proportion of losses in the primary tumor (PT) was observed (ratio of gains to losses: PT, 4.75; M1, 6.3). Almost all the imbalances in M1 were detected in the primary tumor. No chromosomal alterations were identified with CGH in tissue samples dissected at 2 cm from the primary tumor (M2). In all samples, dysplastic morphologic changes decreased with distance from the primary tumor, which correlates with the observed lower level of genetic changes. We suggest that gains of genetic material on 15q and 21q are early events in malignant progression of squamous cell carcinoma, followed by gains on 3q, 8q, and 11q, and losses on 3p and 9p at later stages. Based on our cytogenetic data, we discuss the monoclonal model followed by lateral epithelial spread as an explanation of multiple head and neck squamous cell carcinomas.

Tissue response and biomaterial integration: the efficacy of in vitro methods

Implantation involves tissue trauma, which evokes an inflammatory response, coupled to a wound healing reaction, involving angiogenesis, fibroblast activation and matrix remodelling. Until now the type and extent of such reactions to give optimal integration of various biomaterials are practically unknown. Three principal fields of research can yield useful data to understand these phenomena better: studies on explanted biomaterials, animal models and relevant in vitro techniques. This paper will present examples of the latter field and the application of endothelial cell (EC) culture systems to study the effects of important tissue (e.g. pro-inflammatory cytokines, chemokines) and material (e.g. metal ions, particulate debris) factors on the regulation of the inflammatory and angiogenic response. A central feature is the use of microvascular endothelial cells (MEC), which can be used in both 2-and 3-dimensional (3-D) assays. We have also used genetic manipulation to develop a permanent MEC line from the human lung (HPMEC-ST1), which is being tested for its suitability to study cell-biomaterial interactions. In addition, suitable in vitro techniques are being developed in order to investigate drug delivery systems (DDS). Of particular interest is the targeting of the central nervous system, our approach being to establish a human model of the blood-brain barrier (BBB). A mainstay of our scientific philosophy is that such in vitro methods can make an important contribution to understanding biological reactions at the tissue-biomaterial interface and thus further a causal approach to tissue engineering (TE) and drug delivery applications.

Differential adhesion of polymorphous neutrophilic granulocytes to macro- and microvascular endothelial cells under flow conditions

OBJECTIVE

As one of the important active barriers in the human organism, endothelial cells (EC) play a central role in the biological reaction to a variety of stimuli, e.g. during the induction and regulation of inflammation, as well as in the reaction to transplantation and biomaterial implantation. In the study of endothelial function, the most widely used in vitro model is that of human umbilical vein EC (HUVEC), i.e. an EC type of embryonic and macrovascular origin. However, many of the important pathological processes occur at microvascular level, thus questioning the validity of the HUVEC model. Moreover, the morphological and functional heterogeneity of the endothelium in the various organs, e.g. kidney, liver and lung, must be taken into consideration. The purpose of the present study was to use a dynamic cell culture system to compare the reactions of HUVEC and human pulmonary microvascular EC (HPMEC) to pro-inflammatory stimulation.

METHODS

HUVEC and HPMEC in monolayer culture were stimulated by tumor necrosis factor-alpha (TNFalpha) in a parallel-plate flow chamber. Short- (4 h) and long-term (12 h) stimulation were compared. As a functional parameter, the adhesion of human peripheral blood polymorphonuclear granulocytes (PMN) to EC was quantitated both under venous and arterial flow conditions.

RESULTS

Short-term (4 h) TNFalpha stimulation and venous flow conditions elicited a 32% higher PMN adhesion to HPMEC compared with HUVEC, whereas under arterial flow conditions no statistically significant differences were found. Following longer-term (12 h) TNFalpha stimulation, PMN adhesion to HPMEC was 65% higher than to HUVEC under venous flow. Under arterial flow no differences were detected.

CONCLUSION

The present results provide new data on the heterogeneity of the endothelium and affect a central element in microvascular pathology, namely granulocyte-endothelial interactions. Moreover, this paper emphasizes the necessity to evaluate the in vitro models of the endothelium with respect to the extrapolation to the situation in vivo.

Generation of human pulmonary microvascular endothelial cell lines

The limited lifespan of human microvascular endothelial cells in cell culture represents a major obstacle for the study of microvascular pathobiology. To date, no endothelial cell line is available that demonstrates all of the fundamental characteristics of microvascular endothelial cells. We have generated endothelial cell lines from human pulmonary microvascular endothelial cells (HPMEC) isolated from adult donors. HPMEC were cotransfected with a plasmid encoding the catalytic component of telomerase (hTERT) and a plasmid encoding the simian virus 40 (SV40) large T antigen. Cells transfected with either plasmid alone had an extended lifespan, but the cultures eventually entered crisis after several months of proliferation. Only those cells that were transfected with both plasmids acquired the capacity to grow in vitro without demonstrating major crisis, and these cells have been in culture for 24 months. HPMEC isolated from two different donors were used, generating two populations of immortalized cells, HPMEC-ST1 and HPMEC-ST2. Single cell-derived clones of the immortalized cells HPMEC-ST1 exhibited growth characteristics that were similar to those of the parental HPMEC. One selected clone, HPMEC-ST1.6R, displayed all major constitutively expressed and inducible endothelial phenotypic markers, including platelet endothelial cell adhesion molecule (PECAM-1, CD31), von Willebrand factor (vWF), and the adhesion molecules, intercellular adhesion molecule (ICAM-1), vascular adhesion molecule (VCAM-1), and E-selectin. In addition, an angiogenic response was demonstrated by sprout formation on a biological extracellular matrix (Matrigel). The HPMEC-ST1.6R cells did not form tumors in nude mice. The microvascular endothelial cell line, HPMEC-ST1.6R, will be a valuable tool for the study of microvascular endothelial physiology and pathology including gene expression, angiogenesis, and tumorigenesis.

Release of non-neuronal acetylcholine from the isolated human placenta is mediated by organic cation transporters

1. The release of acetylcholine was investigated in the human placenta villus, a useful model for the characterization of the non-neuronal cholinergic system. 2. Quinine, an inhibitor of organic cation transporters (OCT), reduced acetylcholine release in a reversible and concentration-dependent manner with an IC(50) value of 5 microM. The maximal effect, inhibition by 99%, occurred at a concentration of 300 microM. 3. Procaine (100 microM), a sodium channel blocker, and vesamicol (10 microM), an inhibitor of the vesicular acetylcholine transporter, were ineffective. 4. Corticosterone, an inhibitor of OCT subtype 1, 2 and 3 reduced acetylcholine in a concentration-dependent manner with an IC(50) value of 2 microM. 5. Substrates of OCT subtype 1, 2 and 3 (amiloride, cimetidine, guanidine, noradrenaline, verapamil) inhibited acetylcholine release, whereas carnitine, a substrate of subtype OCTN2, exerted no effect. 6. Long term exposure (48 and 72 h) of villus strips to anti-sense oligonucleotides (5 microM) directed against transcription of OCT1 and OCT3 reduced the release of acetylcholine, whereas OCT2 anti-sense oliogonucleotides were ineffective. 7. It is concluded that the release of non-neuronal acetylcholine from the human placenta is mediated via organic cation transporters of the OCT1 and OCT3 subtype.

Endosonography of insulin-secreting and clinically non-functioning neuroendocrine tumors of the pancreas: criteria for benignancy and malignancy

OBJECTIVE

Endosonography is a powerful tool in the diagnosis of gastroenteropancreatic neuroendocrine tumors. This study was performed in order to characterize endosonographic criteria of malignant and benign neuroendocrine pancreatic tumors focussing on those typically presented to endocrinologists, i.e. insulin-secreting tumors and clinically non-functioning tumors in MEN-1.

DESIGN

We studied six benign insulinomas, four hormone inactive benign neuroendocrine adenomas in MEN-1, and three non-metastatic neuroendocrine carcinomas with clinically symptomatic insulin secretion.

METHODS

Endosonography was performed using Pentax FG 32 UA endosonoscope with a longitudinal 7.5 MHz sector array.

RESULTS

Tumor diameter was larger in malignant tumors (19 - 70 / 47.0 +/- 25.9 mm) than in benign lesions (2.3 - 19 / 9.7 +/- 5.8 mm). Hypoechoic echogeneity was more or less present in benign and in malignant tumors and could not be used as a criteria for differential diagnosis. Heterogeneous or multinodular structure on endosonographic imaging however, was an exclusive feature of malignant tumors. Echo-free areas representing cystic transformation or necrosis and vascular invasion were additional signs of malignancy.

CONCLUSIONS

Molecular genetic diagnosis of MEN-1 and new therapeutic developments such as endoscopic surgery make sufficient imaging procedures in the management of neuroendocrine pancreatic tumors mandatory. Besides valid detection and exact localization, endosonography provides criteria for benign and malignant tumors and thus may be helpful in planning therapeutic strategies.

Release of non-neuronal acetylcholine from the human placenta: difference to neuronal acetylcholine

The synthesis and release of non-neuronal acetylcholine, a widely expressed signaling molecule, were investigated in the human placenta. This tissue is free of cholinergic neurons, i.e. a contamination of neuronal acetylcholine can be excluded. The villus showed a choline acetyltransferase (ChAT) activity of 0.65 nmol/mg protein per h and contained 500 nmol acetylcholine/g dry weight. In the absence of cholinesterase inhibitors the release of acetylcholine from isolated villus pieces amounted to 1.3 nmol/g wet weight per 10 min corresponding to a fractional release rate of 0.13% per min. The following substances did not significantly modify the release of acetylcholine: oxotremorine (1 microM), scopolamine (1 microM), (+)-tubocurarine (30 microM), forskolin (30 microM), ouabain (10 microM), 4alpha-phorbol 12,13-didecanoate (1 microM) and tetrodotoxin (1 microM). Removal of extracellular calcium, phorbol 12,13-dibutyrate (1 microM) and colchicine (100 microM) reduced the acetylcholine release between 30% and 50%. High potassium chloride (54 mM and 108 mM) increased the acetylcholine release slightly (by about 30%). A concentration of 10 microM nicotine was ineffective, but 100 microM nicotine enhanced acetylcholine release gradually over a 50-min period without desensitization of the response. The facilitatory effect of nicotine was prevented by 30 microM (+)-tubocurarine. Inhibitors of cholinesterase (physostigmine, neostigmine; 3 microM) facilitated the efflux of acetylcholine about sixfold, and a combination of both (+)-tubocurarine (30 microM) and scopolamine (1 microM) halved the enhancing effect. In conclusion, release mechanisms differ between non-neuronal and neuronal acetylcholine. Facilitatory nicotine receptors are present which are activated by applied nicotine or by blocking cholinesterase. Thus, cholinesterase inhibitors increase assayed acetylcholine by two mechanisms, protection of hydrolysis and stimulation of facilitatory nicotine receptors.

Histological grading, growth fraction and DNA-ploidy as criteria for the treatment of pharyngeal and supraglottic squamous cell carcinomas: a preliminary, prospective study

BACKGROUND

Individualized treatment for patients with squamous cell carcinomas is most desirable. Biologic parameters of tumors may provide relevant criteria to achieve this goal. The aim of this study was: (1) to avoid elective neck dissection in patients with squamous cell carcinomas of the pharynx and supraglottis staged N0 by ultrasonography; (2) to administer postoperative radiotherapy only in patients staged 'highly aggressive' by biologic tumor parameters, in order to reduce patient morbidity and to improve quality of life.

STUDY DESIGN AND METHODS

This prospective trial was performed in 35 patients (any T stage, N0 or N1 by ultrasonographic examination). Tumor biopsies were taken for histological examination and for evaluation of some biological tumor markers. These parameters comprised DNA cytometric examinations, histological grading of the tumor front and immunohistochemical staining for proliferation markers (MIB1, PCNA). Based on these parameters, tumors were classified into 'low aggressive' (group 1) and highly aggressive (group 2) behavior. In all patients, second primaries were excluded by endoscopy, and the presenting tumor was resected with clear margins. In cases of ultrasonographically enlarged lymph nodes, functional neck dissection was performed. When biologic tumor profile showed low aggressive behavior (group 1), no postoperative radiotherapy was advised. In cases of highly aggressive tumors, radiotherapy was recommended postoperatively independent of all other parameters (group 2a and 2b).

RESULTS

The average follow-up was 36 months (range 16-65 months). Fifteen patients were included in group 1, 20 patients in group 2. Three patients with highly aggressive tumors who refused RTx were regarded independently (group 2b). In this pilot study of 35 patients, there was no difference in disease-free survival between group 1 and group 2a. Twenty-five of 35 patients were alive with no evidence of disease 29-65 months after treatment (3 died of disease; 5 died of second primary carcinomas; 2 died independent of disease). Eleven of 15 patients survived disease free in group 1, 13/17 in group 2a. In group 2b, 2 out of 3 patients, who were advised but refused postoperative radiotherapy, had recurrences.

CONCLUSIONS

The results of this preliminary study point towards usefulness of some tumor biologic parameters in decision making for individualized treatment in patients with squamous cell carcinomas.

c-erbB-2 expression in small-cell lung cancer is associated with poor prognosis

Small-cell lung cancer (SCLC) carries a bad prognosis despite good initial response to chemotherapy. It is therefore important to identify molecular markers that influence survival as potential new therapeutic targets. In our study, expression of the tyrosine kinase c-erbB-2 (HER2/neu) receptor in tumor tissues of 107 consecutive newly diagnosed patients with primary SCLC was quantified using a monoclonal antibody directed against the c-terminal domain of c-erbB-2. A clear-cut positive expression of c-erbB-2 was observed in 13% of patients. Surprisingly, c-erbB-2 was an independent prognostic factor (RR = 2.16; p = 0.014) when a proportional-hazard model was adjusted to stage (limited vs. extensive disease) and performance status (WHO I-IV), the most relevant clinical parameters. Similarly, a significant association between c-erbB-2 and survival was obtained if a larger number of clinical parameters were included into the analysis, namely response to chemotherapy, TNM stage, lactate dehydrogenase (LDH), neuron-specific enolase (NSE), gender and age (p = 0.033). Interestingly, c-erbB-2 expression was more relevant for patients with advanced tumors. In the subgroup of patients with bad performance status (WHO II-IV), median survival of patients with undetectable c-erbB-2 expression was 274 days compared with only 23 days for patients with clear-cut positive c-erbB-2 immunohistochemistry (p = 0.0031; log-rank test). Similar results were obtained for patients with extensive disease (p = 0.028) and high TNM stages (T>2 or N>1 or M1; p < 0.068, all comparisons). In contrast, c-erbB-2 expression was not associated with survival in patients with limited disease (p = 0.97), low TNM stages (p > 0.56, all comparisons) and good performance status (p = 0.97). In conclusion, c-erbB-2 is expressed in more than 10% of SCLC. Expression of c-erbB-2 is an independent prognostic factor of survival. The effect of c-erbB-2 expression seems to become more important in advanced stages of the disease. Since c-erbB-2 is a therapeutical target in other types of cancer, further studies to identify the role of c-erbB-2 in SCLC are clearly warranted.

The biological role of non-neuronal acetylcholine in plants and humans

Acetylcholine, one of the most exemplary neurotransmitters, has been detected in bacteria, algae, protozoa, tubellariae and primitive plants, suggesting an extremely early appearance in the evolutionary process and a wide expression in non-neuronal cells. In plants (Urtica dioica), acetylcholine is involved in the regulation of water resorption and photosynthesis. In humans, acetylcholine and/or the synthesizing enzyme, choline acetyltransferase, have been demonstrated in epithelial (airways, alimentary tract, urogenital tract, epidermis), mesothelial (pleura, pericardium), endothelial, muscle and immune cells (granulocytes, lymphocytes, macrophages, mast cells). The widespread expression of non-neuronal acetylcholine is accompanied by the ubiquitous expression of cholinesterase and acetylcholine sensitive receptors (nicotinic, muscarinic). Both receptor populations interact with more or less all cellular signalling pathways. Thus, non-neuronal acetylcholine can be involved in the regulation of basic cell functions like gene expression, proliferation, differentiation, cytoskeletal organization, cell-cell contact (tight and gap junctions, desmosomes), locomotion, migration, ciliary activity, electrical activity, secretion and absorption. Non-neuronal acetylcholine also plays a role in the control of unspecific and specific immune functions. Future experiments should be designed to analyze the cellular effects of acetylcholine in greater detail and to illuminate the involvement of the non-neuronal cholinergic system in the pathogenesis of diseases such as acute and chronic inflammation, local and systemic infection, dementia, atherosclerosis, and finally cancer.

The non-neuronal cholinergic system in the endothelium: evidence and possible pathobiological significance

An increasing body of knowledge indicates that the cholinergic system is not confined to the nervous system, but is practically ubiquitous. The present paper will address the question of the non-neuronal cholinergic system in vascular endothelial cells (EC). In tissue sections of human skin, immunohistochemical studies using confocal laser scanning microscopy showed ChAT (choline acetyltransferase) activity in the EC of dermal blood vessels. Positive ChAT immunoreactivity was also demonstrated in monolayer cultures of human umbilical vein EC (HUVEC) and a human angiosarcoma EC line (HAEND). That the synthesizing enzyme is not only present in EC, but also active was shown by measuring ChAT activity. Thus, in HUVEC cultures, ChAT activity amounted to 0.78 +/- 0.15 nmol x mg protein(-1) x h(-1) (n = 3), but was only partially (about 50%) inhibited by the ChAT inhibitor bromoacetylcholine (30 microM). In HPLC measurements, a concentration of 22 +/- 2 pmol acetylcholine (ACh) per 10(6) cells was found (n = 6). However, using a cholinesterase-packed analytical column to check the identity of the acetylcholine peak, the peak height was found to be reduced, although a significant peak still remained, indicating the existence of a compound closely related to ACh. Further immunocytochemical experiments indicated that EC in vitro also express the vesicular acetylcholine transporter (VAChT) system. Preliminary immunoelectron microscopic studies suggest a topographical association of VAChT with endothelial endocytotic vesicles. The presented experiments clearly demonstrate the existence of essential elements of the cholinergic system (ChAT, VAChT, ACh) in the human endothelium. The biological functions of ACh synthesized by endothelial cells are the focus of ongoing research activity.

Inhibin-alpha CD99, HEA125, PLAP, and chromogranin immunoreactivity in testicular neoplasms and the androgen insensitivity syndrome

We investigated 115 testicular and 3 epididymal tumors and 6 cases of the complete androgen insensitivity syndrome (AIS) for the expression of inhibin-alpha, CD99, HEA125, PLAP, and chromogranin, using monoclonal antibodies and standard immunhistochemical techniques. Ihibin-alpha was detected in the neoplastic cells in 27 of 27 primary Leydig cell tumors (LCTs), 1 of 1 metastatic LCT, 6 of 20 Sertoli cell tumors (SCTs), 4 of 5 juvenile granulosa cell tumors (GCTs), and 2 of 5 unclassified sex cord-stromal tumors (USCSTs). Except for 2 choriocarcinomas, the choriocarcinomatous component of 1 mixed germ cell tumor, and a small focus of inhibin-positive syncytiotrophoblast in 1 embryonal carcinoma, inhibin-a immunoreactivity was not present in the neoplastic cells of the 38 remaining testicular germ cell tumors; 11 B-cell and 1 T-cell lymphomas; 1 granulocytic sarcoma; and 1 rhabdomyosarcoma of the testis; 1 adenoma of the rete testis, and 3 adenomatoid tumors of the epididymis. Inhibin-alpha immunoreactivity was present in the Sertoli cells and Leydig cells in 5 testicular hamartomas and in 1 Sertoli cell adenoma in 6 cases of AIS; both Sertoli and Leydig cells were also positive in the extranodular testicular parenchyma present in 2 of these cases. CD99 was detected in 10 of 15 primary LCTs, 1 of 7 SCTs, 3 of 5 JGCTs, and in 1 of 5 USCSTs but was not found in any tumor outside the sex cord-stromal category. HEA125 immunostaining was not detected in sex cord-stromal tumors; however, 3 of 12 seminomas, 3 of 12 embryonal carcinomas, 6 of 8 yolk sac tumors, and 1 of 2 teratomas were HEA125 positive. PLAP was not detected in sex cord-stromal tumors except for 4 of 15 primary LCTs but was present in most germ cell tumors. Chromogranin immunostaining was present in the sex cord-like element in 1 of 5 USCSTs, 1 of 8 YSTs, 1 of 2 teratomas, and in 1 of 1 rete adenoma, and in normal adjacent rete testis. In conclusion, although inhibin-alpha and PLAP, and, to a somewhat lesser extent, CD99 and HEA125 immunostaining are helpful in the differential diagnosis of certain testicular neoplasms that are difficult to distinguish on morphologic grounds, chromogranin is far less helpful in this context.

[A case report: suppurative pericardial effusion]

We present the case of a 67 year old woman who was resuscitated due to cardiac tamponade. Examination of the pus fluid showed a bacterial infection with streptococcus milleri. Four days before resuscitation the patient experienced weakness, dyspnoea, increased temperature (39 degrees C), swelling of the neck, and pain on swallowing. Using computed tomography, examination revealed an infection extending from the right tonsil to the mediastinum and into the pericardium. After surgery to remove the retropharyngeal abscess, the patient healed well. Therefore, on presentation of a cardiac tamponade, possible hematogenous or lymphogenous causes or per continuitatem infections should always be considered. In this case the germs in the fluid and the typical patient history indicated an oropharyngeal reason.

Microcirculatory dysfunction in sepsis: a pathogenetic basis for therapy?

Sepsis is a frequent complication of multiple organ dysfunction syndrome and remains a major problem of intensive care medicine. It is also a common factor in the final cause of death in hospital populations. Clinical observations, assisted by invasive monitoring techniques as well as pathological-anatomical studies, clearly indicate that microcirculatory dysfunction lies at the centre of sepsis pathogenesis. Numerous animal models, from rodents to primates, many of which employ bacteria or their toxins, especially endotoxins, have helped to shed light on the pathomechanisms leading to this dysregulation in the peripheral circulation. Among these are activation of humoral and cellular inflammatory mediator systems, with special emphasis on neutrophil-endothelial interactions, affecting endothelial barrier function and vasoregulation and ultimately leading to severely perturbed oxygen transport and utilization. In vitro studies have provided more insight into the molecular mechanisms involved in this microcirculatory dysfunction, although much more attention must be directed towards microvascular endothelial cells and the role of heterogeneity of response in various vascular beds. These experimental data must in turn be validated by comparing with the human in situ situation, both clinical and morphological. This review aims at a critical appraisal of the clinical and experimental evidence for sepsis-induced dysregulation of the microcirculation and how knowledge of the underlying cellular and molecular pathology could be used to make therapy more rational and effective. To date, therapeutic approaches, such as anti-cytokine and anti-oxidant regimens, which have been highly successful in experimental models, have failed to demonstrate clinical efficacy. Newer approaches, such as targeting the coagulation system, nitric oxide synthesis or intracellular signal transduction, are also discussed. The necessity to focus on the role of anti-inflammatory mediators, as well as the pathogenetic significance of important molecular groups, such as the heat shock proteins, which until now have been given scant attention, will be stressed.

Biomaterial-induced sarcoma: A novel model to study preneoplastic change

In the study of carcinogenesis most interest has focused on carcinomas, as they represent the majority of human cancers. The recognition of the adenoma-carcinoma sequence both in humans and in animal experimental models has given the field of basic oncology the opportunity to elucidate individual mechanisms in the multistep development of carcinoma. The relative scarcity of human sarcomas coupled with the lack of adequate animal models has hampered understanding of the molecular genetic steps involved. We present an experimental model in the rat in which a high incidence of malignant mesenchymal tumors arise around a subcutaneously implanted biomaterial. Nine commercially available biomaterials were implanted in a total of 490 rats of the Fischer strain for 2 years. On average, macroscopic tumors were found in 25.8% of implantation sites over a period from 26 to 110 weeks after implantation. The most frequent tumors were malignant fibrous histiocytomas and pleomorphic sarcomas, although fibrosarcomas, leiomyosarcomas, and angiosarcomas readily developed, the latter especially around polyurethane implants. Of particular interest are the results of a detailed histological study of the capsules around the implanted biomaterials without tumors. Here a spectrum of change from focal proliferative lesions through preneoplastic proliferation to incipient sarcoma could be observed. A parallel immunohistochemical study of peri-implant capsules showed that proliferating cell nuclear antigen was of particular help in identifying these atypical proliferative lesions. To our knowledge this is the first description of a sarcoma model in which preneoplastic lesions can be readily identified and also reproducibly induced. This model provides the molecular biologist with defined stages in the development of mesenchymal malignancy, with which the multistage tumorigenesis hypothesis can be tested, analogous to the well-known adenoma-carcinoma sequence.

Microcirculatory dysfunction in sepsis: a pathogenetic basis for therapy?

Sepsis is a frequent complication of multiple organ dysfunction syndrome and remains a major problem of intensive care medicine. It is also a common factor in the final cause of death in hospital populations. Clinical observations, assisted by invasive monitoring techniques as well as pathological-anatomical studies, clearly indicate that microcirculatory dysfunction lies at the centre of sepsis pathogenesis. Numerous animal models, from rodents to primates, many of which employ bacteria or their toxins, especially endotoxins, have helped to shed light on the pathomechanisms leading to this dysregulation in the peripheral circulation. Among these are activation of humoral and cellular inflammatory mediator systems, with special emphasis on neutrophil-endothelial interactions, affecting endothelial barrier function and vasoregulation and ultimately leading to severely perturbed oxygen transport and utilization. In vitro studies have provided more insight into the molecular mechanisms involved in this microcirculatory dysfunction, although much more attention must be directed towards microvascular endothelial cells and the role of heterogeneity of response in various vascular beds. These experimental data must in turn be validated by comparing with the human in situ situation, both clinical and morphological. This review aims at a critical appraisal of the clinical and experimental evidence for sepsis-induced dysregulation of the microcirculation and how knowledge of the underlying cellular and molecular pathology could be used to make therapy more rational and effective. To date, therapeutic approaches, such as anti-cytokine and anti-oxidant regimens, which have been highly successful in experimental models, have failed to demonstrate clinical efficacy. Newer approaches, such as targeting the coagulation system, nitric oxide synthesis or intracellular signal transduction, are also discussed. The necessity to focus on the role of anti-inflammatory mediators, as well as the pathogenetic significance of important molecular groups, such as the heat shock proteins, which until now have been given scant attention, will be stressed.

[Calciphylaxis: ischemic tissue necrosis in chronic renal failure. Case report and review of the literature]

Calciphylaxis is a rare but potentially life-threatening complication in chronic renal failure. It is characterized by ischemic tissue necrosis primarily of the skin. The typical histopathologic finding is microvascular calcification with endovascular fibrosis. Patients typically present with violaceous, mottled and painful lesions which tend to progress to non-healing ulcers and necrosis. Most frequently the lower extremities are involved in a symmetric fashion but the trunk may also be affected. Sepsis from superinfection of the lesions accounts for the high mortality of this disease which is of importance for dermatologists and nephrologists alike. 61-year-old female patient developed lesions of calciphylaxis on both calves two years after beginning hemodialysis to treat renal failure due to diabetic glomerulosclerosis. We discuss aspects of the pathogenesis of calciphylaxis, as well as diagnosis, treatment and means of prevention, and review the current literature.

Induction of stress proteins in human endothelial cells by heavy metal ions and heat shock

In the present study, we compared the induction of heat shock proteins (HSPs) by heat and heavy metal ions in three different endothelial cell types, namely, human umbilical vein endothelial cells, human pulmonary microvascular endothelial cells, and the cell line EA.hy 926. Our results show that especially Zn(2+) and Cd(2+) are inducers of 70-kDa (HSP70), 60-kDa (HSP60), 32-kDa (HSP32), and 27-kDa (HSP27) HSPs. The strength of inducibility is specific for each HSP. Ni(2+) and Co(2+) only show an inducible effect at very high concentrations, that is, in the clearly cytotoxic range. Furthermore, we investigated the time course of HSP expression and the involvement of heat shock factor-1. Our study demonstrates that the three endothelial cell types that were under investigation show comparable stress protein expression when treated with heavy metal ions or heat shock. The expression of stress proteins may be used as an early marker for the toxic damage of cells. This damage can be an inducer of acute respiratory distress syndrome in which microvascular endothelial lesions occur early. Our study provides evidence that human umbilical vein endothelial cells or EA.hy 926 cells, which are much more easily isolated and/or cultivated than pulmonary microvascular endothelial cells, could be used as alternative cell culture systems for studies on cellular dysfunction in the lung caused by toxic substances, certainly with respect to the expression of HSPs.

Endothelial cell cultures as a tool in biomaterial research

Progress in biocompatibility and tissue engineering would today be inconceivable without the aid of in vitro techniques. Endothelial cell cultures represent a valuable tool not just in haemocompatibility testing, but also in the concept of designing hybrid organs. In the past endothelial cells (EC) have frequently been used in cytotoxicity testing of materials, especially polymers, used in blood-contacting implants, as well as for investigating seeding technologies for vascular prostheses. At present the exponential development both in theory and practice of cell and molecular biology of the endothelium offers great promise in the biomaterial field. Up until now this EC research field has mostly been non-biomaterial orientated. Nevertheless, the relevance for biomaterial research is apparent. Four aspects will be concisely reviewed under the headings inflammation, with special reference to cell adhesion molecules (CAMs) and cytokines, angiogenesis, focusing on the healing response, signal transduction, presenting examples from cytokine- and metal ion-induced up-regulation of genes coding for CAMs, and, finally, endothelial functionality, with emphasis on the principal characteristics of the physiological endothelial phenotype. Finally, the application of these fields to three foci of biomaterial research will be discussed, emphasizing the role of EC culture techniques in controlling the host response to biomaterials (microvascular EC), controlling EC functionality (promoting positive effects and down-regulating negative effects), and tissue engineering (integration of EC into hybrid organs/biosensors). The need for more co-culture and three-dimensional models will be stressed and data from the authors' laboratory presented to illustrate these principles.

[Significance of eosinophilic granulocytes in relation to allergy and aspirin intolerance in patients with sinusitis polyposa]

BACKGROUND

The development of nasal polyps might be influenced by different factors such as mucosal inflammation. Infiltration with eosinophils is a common finding, although in largely different quantitis.

PATIENTS AND METHODS

We investigated 58 patients suffering from nasal polyps who were assigned for endonasal sinus surgery based on endoscopic and CT findings. Out of these patients, 52% have already had sinus surgery and had recurrent polyps. All patients were subjected to both, allergy testing and a functional in vitro test for aspirin intolerance. During surgery, tissue samples were gained and send for histological examination with special respect to eosinophil infiltration.

RESULTS

Eosinophil infiltration was observed in 66% of all patients. 37 patients (64%) exhibited aspirin intolerance only, four (7%) had a positive allergy test only, in 9 patients (15%) both, allergy and aspirin intolerance were diagnosed. Allergy and aspirin intolerance were accompanied by eosinophil tissue infiltration. Eosinophil infiltration was more common and more severe if allergy and aspirin intolerance were found together compared with the tissue eosinophilia in patients with either one entity.

CONCLUSION

This study confirms the importance of eosinophil infiltration in the pathogenesis of severe or recurrent nasal polyps based on allergy and aspirin intolerance. A coincidance of allergy and aspirin intolerance was found in an unexpected high number of patients.

Confocal laser scanning microscopy: A nondestructive subsurface histotomography of healthy human bone

Microscopy of bony tissue usually requires special treatment for decalcification and processing of thin sections. Confocal laser scanning microscopy (CLSM) allows the nondestructive histotomography of organic hard tissue. The aim of this study was to visualize healthy human bone structures and to correlate identical areas in CLSM and conventional light microscopy. Each sample of healthy human lower jaw (n = 20) was divided into three parts: (1) fresh, untreated bony blocks studied by CLSM; (2) MMA-embedded thin sections (without decalcification), HE stained and studied by CLSM and conventional light microscopy (correlation of identical areas); (3) decalcificated, HE stained, histological sections studied by conventional light microscopy. In untreated bony blocks, microstructures such as osteocytes and lamellae were identified by CLSM. These structures could be correlated with conventional light microscopy. In CLSM, subcellular structures cannot yet be interpreted, whereas cytoplastic processes of osteocytes were seen with high contrast. With CLSM, nondestructive histology of cortical bone can be obtained. The risk of artifacts due to pretreatment is minimized, and subsurface visualization does not affect the interpretation.

Modified cryopreservation and xenotransplantation of human parathyroid tissue

INTRODUCTION

A modified cryopreservation technique for human parathyroid tissue was compared with the standard method using a programmed freezer.

METHODS

Total parathyroidectomy was performed in three groups of 6-week-old Rowett nude rats. Group I (control) underwent no transplantation of parathyroid tissue (n=9). After 10 days, the rats of groups II (n=15) and III (n=15) underwent xenotransplantation of 20 mg cryopreserved human parathyroid tissue, which had been stored in liquid nitrogen at -196 degrees C for 1-22 months prior to xenotransplantation. The parathyroid tissue was derived from 15 parathyroidectomized patients with renal hyperparathyroidism. Two tissue samples were obtained from every patient. One sample from every patient was cryopreserved by means of the technique of programmed cryopreservation: programmed freezing of human parathyroid tissue at a controlled rate of -1 degrees C/min to -80 degrees C prior to transfer to liquid nitrogen (group II). The second sample from every patient was cryopreserved by means of a modified cryopreservation technique: immediate placement of human parathyroid tissue in a freezer at -20 degrees C and transfer to liquid nitrogen after 2 h (group III). Calcium and intact parathyroid hormone concentrations in serum were determined over a period of 60 days. Furthermore, individual differences in the calcium concentrations were assessed for each rat on the basis of the calcium levels recorded preoperatively and at day 60.

RESULTS

All animals in the control group developed hypocalcemia. Serum calcium concentrations returned to normal levels 60 days after xenotransplantation of parathyroid tissue, which had been cryopreserved using the modified technique (group III) in 12 of 15 rats (80%). At day 60, serum calcium had normalized in 10 of 15 rats (67%) after xenotransplantation of parathyroid tissue cryopreserved using programmed freezing (group II). After modified cryopreservation (group III), the median individual difference in the calcium concentrations was -0.16 mmol/l after programmed freezing (group II). At the end of the study, a median level of human intact parathyroid hormone of 3.5 pg/ml and 2.4 pg/ml was estimated for groups II and III, respectively. There was no statistical significant difference of the individual differences in the calcium concentrations or of the levels of human intact parathyroid hormone between groups II and III.

CONCLUSION

Human parathyroid tissue was successfully xenografted in the present experimental study. The results obtained after cryopreservation using the described modified technique were equivalent to those recorded after controlled freezing in a programmed freezer. The simplified cryopreservation technique therefore appears to be suitable for human parathyroid tissue.

Hyperlactacidaemia in isolated hyperthermic perfusion of tumour bearing rat limbs: a study of feasibility using a novel infusion solution

PURPOSE

In a methodological study the applicability of hyperlactacidaemia in isolated hyperthermic perfusion of tumour-bearing rat limbs was investigated.

METHODS

In 50 Sprague Dawley rats, DS-sarcoma growth was initiated on the right food dorsum by subcutaneous injection of 0.5 ml ascites cells. In the anaesthetized animals isolated limb perfusion was performed under steady state conditions for 60min using a miniature equipment. Thereafter tumour volume was measured daily. (a) Investigation of feasability: 40 rats were allocated to four groups. Group I: Normothermic perfusion at 38 degrees C, n = 10; Group II: Hyperthermic perfusion at 40-41 degrees C, n = 10; Group III: Normothermic perfusion at 38 degrees C and hyperlactacidaemia of 10 mmol/l, n = 10; Group IV: Hyperthermic perfusion at 40-41 degrees C and hyperlactacidaemia of 10 mmol/l, n = 10. (b) Investigation of survival and histological changes: In group V hyperthermic perfusion at 40-41 degrees C and hyperlactacidaemia of 10 mmol/l, n = 10 was performed. After the animals had died, hip disarticulation of the tumour-bearing limb was performed for histological examination.

RESULTS

Normothermic and hyperthermic perfusion of tumour-bearing rat limbs using miniature equipment was feasible and tolerated by the animals. Regional hyperlactacidaemia of 10 mmol/l could be maintained throughout the perfusions. After combined treatment with hyperthermia and hyperlactacidaemia, tumour volume decreased and extensive tumour necrosis occurred, while in other animals aggressive tumour growth with bone infiltration could be observed.

CONCLUSIONS

The present study demonstrates the applicability of hyperlactacidaemia in hyperthermic isolated limb perfusion in the rat and proved a tumour growth delay due to an induction of tumour necrosis thereafter. Further investigations in other tumour entities and experimental models are required to confirm this impressive therapeutic effect of hyperthermia in combination with hyperlactacidaemia.

Remodeling of peritoneal-like structures by mesothelial cells: its role in peritoneal healing

BACKGROUND

Intraabdominal adhesions are a common complication following laparotomy. Since the exact mechanisms involved in this processes are unknown we have analyzed in vitro the role of mesothelial cells in peritoneal healing.

MATERIAL AND METHODS

Human mesothelial cells from omental tissue were cultivated for 2 weeks in a three-dimensional culture either on or in a collagen type I matrix. The effects of blood and collagen matrix were analyzed by exposing mesothelial cells to an overlying blood clot, simulating intraperitoneal bleeding, or a second collagen layer. The production of collagen types III and IV, fibronectin, and laminin was analyzed with immunohistochemical methods.

RESULTS

Mesothelial cells grown on a collagen matrix formed a monolayer of flat or cobblestone-like cells whereas those cultivated in a collagen matrix exhibited spindle-like morphology. Mesothelial cells failed to grow into an overlying collagen matrix, but did grow into a blood clot, emphasizing a potential role of blood clots in peritoneal adhesion formation. Independent of the culture systems mesothelial cells produced collagen type III, fibronectin, and laminin but not collagen type IV.

CONCLUSIONS

Our experiments demonstrate remodeling of peritoneal-like structures by mesothelial cells in a three-dimensional culture reflecting their putative role in the reepithelialization after serosal defects, and also in the formation of peritoneal adhesions.

Differential expression of cell adhesion molecules in inflamed appendix: correlation with clinical stage

The diagnosis of 'early inflamed', 'recurrent' or 'sub-acute' appendicitis is often difficult and accompanied by controversies between clinical data, histological findings, and their interpretation. The expression of the intercellular cell adhesion molecule-1 (ICAM-1), the vascular cell adhesion molecule-1 (VCAM-1), and E-selectin has been studied in 61 appendicectomy specimens for possible use as a diagnostic tool. This study demonstrates a different expression of CAM by endothelial (EC) and mesothelial cells (MC) in the various stages of appendicitis, with early E-selectin and ICAM-1 expression in EC, followed by VCAM-1 in EC and MC. Appendices from patients with prolonged clinical symptoms defined by clinicians as 'chronic' appendicitis showed VCAM-1 expression and occasionally weak expression of E-selectin in EC. In several cases, discrepancies were found between the pre-operative 'clinical' diagnosis, the histomorphological findings, and the immunohistological results. In this context, the expression of E-selectin and VCAM-1 in comparison with the histological features has potential significance in the diagnosis of 'early acute', 'sub-acute' or 'recurrent' appendicitis. In addition, a correlation was demonstrated between the histological stages of appendicitis and the kinetics of CAM expression. The study also indicates that the time course of E-selectin expression in vivo is longer than is suggested from in vitro data.