Accumulation of small hyaluronan oligosaccharides in tumour interstitial fluid correlates with lymphatic invasion and lymph node metastasis

BACKGROUND

Association studies have implicated the glycosaminoglycan hyaluronan (hyaluronic acid, HA) and its degrading enzymes the hyaluronidases in tumour progression and metastasis. Oligosaccharides of degraded HA have been ascribed a number of biological functions that are not exerted by high-molecular-weight HA (HMW-HA). However, whether these small HA oligosaccharides (sHA) have a role in tumour progression currently remains uncertain due to an inability to analyse their concentration in tumours.

METHODS

We report a novel method to determine the concentration of sHA ranging from 6 to 25 disaccharides in tumour interstitial fluid (TIF). Levels of sHA were measured in TIF from experimental rat tumours and human colorectal tumours.

RESULTS

While the majority of HA in TIF is HMW-HA, concentrations of sHA up to 6 μg ml(-1) were detected in a subset of tumours, but not in interstitial fluid from healthy tissues. In a cohort of 72 colorectal cancer patients we found that increased sHA concentrations in TIF are associated with lymphatic vessel invasion by tumour cells and the formation of lymph node metastasis.

CONCLUSIONS

These data document for the first time the pathophysiological concentration of sHA in tumours, and provide evidence of a role for sHA in tumour progression.

[Maxillary ameloblastoma extending into the sinonasal tract]

Maxillary ameloblastomas can extensively expand into the paranasal sinuses or even the nasal cavity due to a slow growth pattern. Sinusitis is rarely the first tumor-related complaint. Due to the various growth forms of ameloblastomas the challenging histological differential diagnosis includes several other odontogenic as well as benign and malignant non-odontogenic tumors, e.g. tumors from the mucosa of the paranasal sinuses, salivary glands and Rathke's pouch. Despite the radical surgical approach a complete resection with wide margins cannot always be achieved. Maxillary ameloblastomas show the highest recurrence rates.

Gastrin mediated down regulation of ghrelin and its pathophysiological role in atrophic gastritis

The gastric hormone ghrelin is known as an important factor for energy homeostasis, appetite regulation and control of body weight. So far, ghrelin has mainly been examined as a serological marker for gastrointestinal diseases, and only a few publications have highlighted its role in local effects like mucus secretion. Ghrelin can be regarded as a gastroprotective factor, but little is known about the distribution and activity of ghrelin cells in pathologically modified tissues. We aimed to examine the morphological changes in ghrelin expression under several inflammatory, metaplastic and carcinogenic conditions of the upper gastrointestinal tract. In particular, autoimmune gastritis showed interesting remodeling effects in terms of ghrelin expression within neuroendocrine cell hyperplasia by immunohistochemistry. Using confocal laser microscopy, the gastrin/cholecystokinin receptor (CCKB) could be detected on normal ghrelin cells as well as in autoimmune gastritis. Functionally, we found evidence for a physiological interaction between gastrin and ghrelin in a primary rodent cell culture model. Additionally, we gathered serological data from patients with different basic gastrin levels due to long-term autoimmune gastritis or short-term proton pump inhibitor treatment with slightly reactive plasma gastrin elevations. Total ghrelin plasma levels showed a significantly inverse correlation with gastrin under long-term conditions. Autoimmune gastritis as a relevant condition within gastric carcinogenesis therefore has two effects on ghrelin-positive cells due to hypergastrinemia. On the one hand, gastrin stimulates the proliferation of ghrelinpositive cells as integral part of neuroendocrine cell hyperplasia, while on the other hand, plasma ghrelin is reduced by gastrin and lost in pseudopyloric and intestinal metaplastic areas. Ghrelin is necessary for the maintenance of the mucosal barrier and might play a role in gastric carcinogenesis, if altered under these pre neoplastic conditions.

COX-2, TFF1, and Src define better prognosis in young patients with gastric cancer

BACKGROUND AND OBJECTIVES

Despite its dwindling occurrence, gastric cancer remains a leading cause of cancer related mortality worldwide. Molecular determinants of prognosis that impact survival are being sought out as a means to facilitate rational clinical decision-making and enhance patient management. In this study, we evaluated three molecules implicated in gastric carcinogenesis and demonstrated that the differential expression of cyclooxygenase-2 (COX-2) and the viral oncogene homolog Src proteins could explain the differences in survival observed in patients older and younger than 50 years of age.

METHODS

We evaluated 5-year survival in a cohort of 423 gastric cancer patients using chronological age as a variable. Additionally, we assessed the protein expression of three molecules (COX-2, TFF1, Src) implicated in the pathogenesis of gastric cancer using immunohistochemistry.

RESULTS

We found that patients younger than 50 years of age had a better 5-year survival rate in all tumor stages. We found that the expression of COX-2 and Src correlated significantly with survival in this group without any significant impact attributable to TFF1.

CONCLUSIONS

Our study demonstrates that young gastric cancer patients have a better prognostic outlook that could in part be explained by the differential expression of COX-2 and Src.

Localised massive tumourous xanthomatosis of the small intestine

INTRODUCTION

There are various disorders of the intestine described with accumulations of vacuolated macrophages including single or multiple xanthelasmata, Wolman's disease, cholesteryl ester storage disease (CESD), xanthomatogranulomatotic disease and xantheloma disseminatum.

CLINICAL CASE

In this paper, we report on an exceptional case of a 68-year-old male patient with a localised, massive accumulation of vacuolated, most likely lipid-loaded macrophages with an infiltrative pattern in the muscularis mucosa and propria of the small intestine leading to a tumourous mass requiring surgical removal due to impaired gut function. No enlargement of the liver or the spleen and no evidence of general abnormal lipid storage were detected elsewhere. No evidence of Wolman's or CESD was present. Also, on the ultra-structural level, the macrophages contained no cholesterol clefts typical for either Wolman's and CESD. Instead, largely empty, partly large vacuoles were seen, which most likely contained fatty acids removed during processing.

DISCUSSION

The pathogenetic mechanism of the massive local accumulation of histiocytic cells in this part of the intestine in our case remains un-clear. In summary, this case demonstrates that on rare occasions histiocytic proliferations can mimic tumourous masses with severe functional impairment of the intestine and thus should be in the differential diagnosis of gastrointestinal motility disorders.

Hyperthermic intraperitoneal chemoperfusion (HIPEC) decrease wound strength of colonic anastomosis in a rat model

BACKGROUND AND AIMS

There is controversy about the effect of the influence of hyperthermia and chemotherapeutic agents on the healing of intestinal anastomosis. The effects of hyperthermic intraperitoneal chemoperfusion (HIPEC) of wound healing after colonic anastomosis were investigated in a rat model.

MATERIALS AND METHODS

Thirty-six Wag/Rija rats were randomized into three groups of 12 animals each: group I: control (only colonic anastomosis was performed) (n = 12); group II: HIPEC (mitomycin C in a concentration of 20 mg/m(2) (n = 12) colonic anastomosis was performed before HIPEC; group III: HIPEC (mitomycin C in a concentration of 20 mg/m(2) (n = 12) colonic anastomosis was performed after HIPEC. Bursting pressure and bursting sites were recorded 4 and 10 days after intervention. Collagen deposits, inflammation and foreign body reactions were evaluated.

RESULTS

Lower bursting pressure and lost of collagen were found in both HIPEC groups and compared with the control group. There was almost no difference between both HIPEC groups. They were noted overwhelmingly at the anastomosis in the HIPEC group. The degree of collagen accumulation was well-correlated with bursting pressure.

CONCLUSION

These results have shown that hyperthermic intraperitoneal chemoperfusion (HIPEC) impairs wound healing in colonic anastomosis in rats.

[Pasqualini's syndrome]

INTRODUCTION

Pasqualini's syndrome is an isolated, incretory functional disorder of the testes with a secondary Leydig cell insufficiency but, unlike Klinefelder's syndrome, with normal spermiogenesis and fertility. This unusual form of hypogonadism is caused by an inherent LH secretion disorder of the pituitary gland. The result of this is the secondary Leydig cell insufficiency and a corresponding peripheral androgen deficiency. In this communication we present the case of a 67-year-old man with Pasqualini's syndrome and a histologically confirmed left seminoma. In view of the current lack of data and our experience, we describe the properties of this uncommon syndrome; therapy, prognosis and possible relationship with seminoma are discussed in more detail.

CASE REPORT

The 67-year-old male presented in our outpatient department with the urgent suspicion of a left testicular tumour as a painless swelling of the testis since about three months. In the case history we found a previously diagnosed hypogonadotropic hypogonadism, which is described in the literature as the so-called Pasqualini syndrome. On palpation, the left testis was about fist-size, scirrhous, mildly pressure sensitive and highly suspicious. Sonography of the testes revealed the enlarged left testis to be completely inhomogeneous with hypo- and hyperdense areas and large spatial requirements with unremarkable perfusion. On the basis of the clinically and sonographically supported diagnosis of a tumour of the left testis and inguinal exposure of the testes was performed. Intraoperative histology of a sample confirmed the diagnosis of a testicular tumour in the sense of a seminoma. A high left ablatio testis was carried out.

DISCUSSION

The occurrence of testicular tumours of the seminoma type in association with Pasqualini's syndrome has not previously been described in the literature. Thus, we assume that the seminoma had occurred at this age independently of the Pasqualini syndrome. For the treatment of Pasqualini's syndrome not only hCG but also testosterone have been employed with success. The patient must continue therapy for his whole life. The results of interruption tests confirm that it is not a passing ailment but rather a persisting, endogenous disease. PRACTICAL CONCLUSIONS: Since the molecular genetics and genesis of this disease have not been clarified unambiguously, further clinical and experimental studies are necessary in order to better understand the disease. An increased risk of testicular tumours has not yet been observed on account of the small number of cases of Pasqualini's syndrome.

[Congenital cystic juvenile granulosa cell tumor of the testes. Scrotal space-occupying lesion in a male neonate]

This article reports on a newborn with a scrotal space-occupying lesion and histologically proven granulosa cell tumor of the testes. A massive scrotal space-occupying lesion was diagnosed in a full-term male neonate with a birth weight of 2,260 g and body length of 45 cm. Sonography of the right testicle revealed a mass 6x6x4 cm in size which was multiply septate and cystic. The testicular parenchyma was poorly defined with a Swiss cheese appearance. Chemical analysis of blood serum evidenced normal levels of testosterone, beta-HCG, and inhibin B as well as physiologically a clearly elevated alpha-fetoprotein level at 35,350 ng/ml. Based on the clinical and sonographic findings of the right testicle, inguinal surgical exposure of the testes was undertaken. Since there was hardly any testicular parenchyma, we decided to perform high inguinal ablation of the right testicle. This case report confirms that congenital granulosa cell tumors usually exhibit benign behavior during the neonatal period.

Histological response of peritoneal carcinomatosis after hyperthermic intraperitoneal chemoperfusion (HIPEC) in experimental investigations

Background

In selected patients with peritoneal carcinomatosis from colorectal cancer prognosis can be improved by hyperthermic intraperitoneal chemotherapy (HIPEC) after cytoreductive surgery. The aim of this study was to evaluate the tumor response of peritoneal carcinomatosis in tumor-bearing rats treated with HIPEC.

Methods

CC531 colon carcinoma (2,5 × 10⁶ cells), implanted intraperitoneally in Wag/Rija rats, was treated by hyperthermic intraperitoneal chemotherapy. After 10 days of tumor growth the animals were randomized into five groups of six animals each: group I: control (n = 6), group II: sham operated animals (n = 6), group III: hyperthermic intraperitoneal perfusion (HIP) without cytostatic drugs, group IV: HIPEC with mitomycin C in a concentration of 15 mg/m² (n = 6), group V: mitomycin C i.p. alone in a concentration of 10 mg/m² (n = 6). After 10 days the extent of tumor spread and histological outcome were analysed by autopsy.

Results

All control animals developed extensive intraperitoneal tumor growth. Histological tumor load was significantly reduced in group III and group V and was lowest in group IV. In group II tumor load was significantly higher than in group I. Implanted metastases were significantly decreased in group IV compared with group I and group II.

Conclusion

These findings indicate that HIPEC is an effective treatment for peritoneal carcinomatosis in this animal model. HIPEC reduced macroscopic and microscopic intraperitoneal tumor spread.

[Long-term experiences in the therapy of esthesioneuroblastoma]

BACKGROUND

Esthesioneuroblastoma is a rare and clinically variable tumor of nasal sinus and skull base and challenging for modern multidisciplinary therapy. There are no generally known prognostic factors or generally accepted standard therapy regimens.

PATIENTS AND METHODS

Between 1975 and 2001 26 patients were treated after the diagnosis of esthesioneuroblastoma was established. The cases were evaluated retrospectively. According to the classification of Kadish 1 patient (4 %) had stage A, 16 patients (53 %) stage B and 11 cases (43 %) had stage C tumors. Hyams grading could be obtained in 22 cases (81 %). Tumors were in 12 patients (52 %) graded I or II and in 10 cases tumors had grade III or IV (48 %). Operative therapy was performed in 23 patients (88.5 %), being in 5 patients a single mode therapy. In 18 cases combined therapy was performed (surgery and radiotherapy or radiotherapy and chemotherapy).

RESULTS

Actuarial survival was 61.5 % (16/26). Disease specific 10- and 15-year-survival according to the estimation of Kaplan-Meier was 76.2 %. Patients with small tumors (Kadish A/B) had a 15-year-survival of 86.7 % compared to 63.6 % in cases with advanced tumors (Kadish C). In 7 cases (26.9 %) recurrences developed. Salvage therapy was performed in 5 cases (71.4 %) with a success rate and a 15-year survival each of 60 %.

CONCLUSIONS

Therapy of esthesioneuroblastoma is challenging because of rarity and biologic variability of the tumor and and because of lack of a standard therapy. An interdisciplinary multimodal therapeutic approach is necessary especially in case of advanced tumors with promising results. Histopathological grading according to Hyams and tumor stage are important factors for survival and prognosis. Although recurrence can occur with high frequency even after prolonged time interval, long time survival can be improved after aggressive salvage therapy. Therefore longterm follow up is mandatory.

Successful uterus cryopreservation in an animal model

Cryopreservation of whole organs would not only be advantageous for experimental biology but also for transplantation surgery. The objective of this study was to evaluate the feasibility of cryopreserving swine uterus as an experimental model of cryopreservation affecting a whole visceral muscle organ. Organs were frozen slowly (0.2 degrees C/min) after arterial perfusion with 10% dimethyl sulfoxide solution for 10 min and equilibration in this solution for 30 min. Viability of the organs was tested by biochemical parameters, LIVE/DEAD fluorescent staining and capability for contraction in a perfusion system. Ten fresh and ten cryopreserved uteri showed living cells in the LIVE/DEAD assay, and were viable for at least 7 h as shown by their ability to produce rhythmic contractions after oxytocin administration. This is the first report known to us on successful cryopreservation of a whole swine uterus to demonstrate that perfusion with a cryoprotectant and slow freezing provides a promising method for cryopreserving whole organs, and may encourage further studies with other cryoprotective agents and freezing protocols as well as other organs.

The Impact of Immunological Parameters on the Development of Phantom Pain after Major Amputation

OBJECTIVES

To investigate the relationship between local and systemic inflammatory markers and phantom limb pain.

METHODS

In 39 consecutive patients undergoing major amputations nerve biopsies, serum and clinical data was collected. Patients were followed up for 12 months to report on the incidence and severity of phantom limb pain.

RESULTS

After 12 months, 78% of the surviving patients had phantom pain, the symptom usually commencing within 14 days of operation. The severity of macrophage infiltration within the nerve biopsy was negatively correlated to the inception of phantom pain ( P = 0.026). While serum TNF-alpha concentration was positively correlated to mortality ( P = 0.021).

CONCLUSIONS

The immune status existing before the amputation and the local immunological milieu influence the onset of phantom pain.

Neoadjuvant chemotherapy does not increase postoperative complication rate after resection of colorectal liver metastases

BACKGROUND

This paper discusses, whether neoadjuvant chemotherapy has an impact on the rate of postoperative complications after primary resection of liver metastases from colorectal carcinoma.

METHODS

Of 183 patients 64 were studied. The patients were subdivided into two matched groups of 32 patients each-prior neoadjuvant chemotherapy (CT-group) vs. (control-group, primary resection).

RESULTS

There were no postoperative complications in 24 patients of the control group (75%) and 26 patients of the CT-group (81%). Following prior chemotherapy, no major complications such as liver failure were observed, even after extended resections.

CONCLUSION

Neoadjuvant chemotherapy prior to surgical resection of colorectal liver metastases does not result in an increase of postoperative morbidity and mortality.

The Use of an Open-freezing System with Self-seeding for Cryopreservation of Mouse Ovarian Tissue

Chemoradiotherapy in young women with cancer has substantially improved life expectancy in these patients, but these treatments often cause infertility. One method of preserving fertility is to cryopreserve ovarian tissue. In this study, an automatic open-vessel freezing system with self-seeding was tested for cryopreservation of murine ovarian tissue; the mouse is a species widely used in human and veterinary medical research. The freezing system concerned, is used for cryopreservation of oocytes and embryos in Europe. Twenty severe combined immunodeficiency (SCID) mice were ovariectomized. The ovarian tissue was either directly transplanted heterotopically into the neck muscle (group 1, n = 6) or cryopreserved after equilibration with 1.5 M dimethylsulphoxide and propanediol. After thawing, the tissue was transplanted in SCID mice (group 2, n = 6). Before and after thawing, a part of the ovarian tissue was examined with the LIVE/DEAD fluorescent viability staining. The count of follicles revealed intact (fresh 24.1%/thawed 21.7%), impaired (fresh 35.1%/thawed 35.4%), and dead follicles (fresh 40.8%/thawed 42.9%). The healthy follicular loss because of the cryopreservation was 10.0%. All recipient mice were killed after 3 weeks. Transplanted ovarian tissue was found macroscopically in all mice. Histological examination showed several growing follicles in all developmental phases in both groups of SCID mice [group 1 (fresh grafts): 315 +/- 76.3 (mean +/- SD); group 2 (cryopreserved grafts): 237 +/- 63.4]. These results demonstrate that the use of an open-freezing system allows the survival of cryopreserved mouse ovarian tissue.

[Angiomyolipoma of the colon - case report and review of the literature]

Angiomyolipoma is one of the benign hamartomas that is found sporadically or associated with tuberous sclerosis. It is a rare soft tissue tumor involving mostly the kidneys, sometimes other visceral organs. The tumor is composed of smooth muscle cells, adipocytes and small sized hyalinized vessels. We present the case of a 74-year-old man with a bifocal angiomyolipoma of the colon. This diagnosis was confirmed at surgery, where a partial colectomy was performed. Histologic examination disclosed the tumor. The patient had no signs of family history of tuberous sclerosis. Extrarenal angiomyolipoma is rare and this may be the first report of bifocal colonic angiomyolipoma.

Late pulmonary metastasis in uterine PEComa

Perivascular epithelioid cell tumours (PEComas) other than angiomyolipoma, clear cell "sugar" tumour of the lung, and lymphangioleiomyomatosis are very rare mesenchymal tumours. The uterus seems to be the most prevalent site of involvement, but only 13 cases of uterine PEComa have been described. Three of these cases exhibited local aggressive behaviour and only one showed metastasis. Because of the extremely small number of cases, PEComas are considered tumours of uncertain malignant potential. This report describes a 68 year old woman, who presented with multiple pulmonary lesions seven years after the initial diagnosis of well differentiated endometrial stromal sarcoma. Histological and immunohistochemical analysis of the pulmonary lesions, in addition to re-evaluation of the primary uterine tumour, led to the final diagnosis of metastatic uterine PEComa. The findings indicate that any PEComa might have malignant potential. Spreading of this tumour to other organs might become evident even several years after primary manifestation.

Angiogenesis and dendritic cell density are not correlated with metachronous distant metastasis in curatively operated rectal cancer

BACKGROUND AND AIMS

Apart from surgery, treatment of rectal cancer increasingly involves the use of (neo-)adjuvant strategies. To optimize the selection process for these therapy regimens, especially in the field of cellular and molecular biology, new prognostic factors additional to the established TNM system are being investigated.

PATIENTS AND METHODS

Two groups of patients ( n=2x85) with rectal carcinoma curatively treated by surgery alone were studied retrospectively (median follow-up 6.1 years). To exclude the effect of the surgeon only patients free of locally recurrent disease were selected. Patient groups were matched for age, gender, UICC stage, and year of operation (1982-1991) and differed only in subsequent metachronous distant metastatic spread, i.e., the criterion to be studied. The factors investigated in uni- and multivariate analysis were angiogenesis, density of dendritic cells, grading, venous invasion, and lymphatic invasion.

RESULTS

Grading invariably proved to be the only significant prognostic factor. In univariate analysis the absence of venous invasion was also correlated significantly with increased disease-free survival.

CONCLUSION

Angiogenesis and dendritic cell density are not prognostic factors for metachronous distant metastasis in rectal cancer and therefore cannot serve as selection parameters for adjuvant therapy.

Laser capture microdissection and real-time PCR for analysis of glomerular endothelin-1 gene expression in mesangiolysis of rat anti-Thy 1.1 and murine Habu Snake Venom glomerulonephritis

Molecular analysis of pathologic changes in glomeruli requires methods allowing rapid and exact detection of alterations in gene expression. Here, we analyzed endothelin-1 (ET-1) mRNA expression in mesangiolytic glomeruli during the course of a rat and murine model of mesangioproliferative glomerulonephritis (GN). A novel method combining laser capture microdissection (LCM), which permits the precise removal of selected mesangiolytic glomeruli, with a highly sensitive real-time RT-PCR technique was used. Anti-Thy 1.1. GN was introduced in male Sprague-Dawley rats (1.0 mg/kg body weight of OX-7 IV) and Habu Snake Venom GN was introduced in C57BL6 mice (habu snake venom toxin 6 mg/kg body weight IV). The degree of mesangiolysis during both GNs was analyzed using a semiquantitative scoring system. Mesangiolytic glomeruli were microdissected at different days of the diseases (day 2, 6, and 12 in anti-Thy 1.1 GN and days 1, 3, 7, and 14 in Habu Snake Venom GN) and from normal control animals. After RNA extraction and cDNA synthesis, ET-1 gene expression was measured by real-time RT-PCR. In parallel, in anti-Thy 1.1. GN ET-1 mRNA expression was analyzed using semiquantitative nonradioactive in situ hybridization; ET-1 protein expression was investigated by immunohistochemistry. Mesangiolysis peaked at day 6 in anti-Thy1.1 GN and at day 1 in Habu Snake Venom GN. Mesangiolytic glomeruli were easily microdissected on cryostat sections in both models; quantification of mRNA with RT-PCR was reliable and reproducible. Glomerular ET-1 mRNA expression increased during the course of anti-Thy 1.1 GN and Habu Snake Venom GN peaked when mesangiolysis was most pronounced. This was seen by RT-PCR after glomerular LCM and by in situ hybridization; in parallel, glomerular ET-1 protein expression was increased. Combination of LCM and RT-PCR is a reliable method for quantification of localized gene expression in isolated renal structures. The above data argue for an important role of ET-1 in pathogenesis and/or repair of mesangiolysis in experimental mesangioproliferative GN.

Formation of cartilage matrix proteins by BMP-transfected murine mesenchymal stem cells encapsulated in a novel class of alginates

Proliferation and differentiation of wild-type, BMP-2 and BMP-4 transfected cells of C3H10T1/2, a mouse mesenchymal stem cell line that can differentiate into chondrocytes, were studied under monolayer (2D-) and encapsulation (3D-) conditions. Cells were encapsulated in a novel class of alginate. The alginate was of clinical grade (CG) because of complete removal of mitogenic and cytotoxic contaminants by chemical means. Compared to commercial alginates used so far for encapsulation it was characterized by ultra-high viscosity (UHV; viscosity of a 0.1% w/v solution of about 20 cP). In contrast to monolayer cultures, proliferation of cells was prevented when the cells were encapsulated in UHV/CG alginate at the same suspension density. As revealed by immunohistochemistry and quantitative RT-PCR, transfected and wild-type monolayer cells showed synthesis of type I collagen after transfer into differentiation medium, while culture in an alginate scaffold resulted in an upregulation of type II collagen and other hyaline cartilage proteins. BMP-4 transfected cells produced considerably more type II collagen than BMP-2 transfected and wild-type cells. BMP-4 transfected cells were also characterized by type I collagen production up to Day 10 and exhibited transient alkaline phosphatase activity levels that were much higher than the peak values observed for the other two cell lines. The coincidence of the ALP peak values with downregulation of type I collagen in BMP-4 transfected cells suggested that C3H10T1/2 cells differentiate into chondrocytes via a chondroprogenitor-like cell.

[Standardized testing of skeletal implant surfaces with an osteoblast cell culture system. IV. Specific gene expression during differentiation]

Successful osseointegration of an implant depends on the properties of the material of which it is made. A standardized cell culture system for the assessment of the biological effect of material surfaces has already been described. In the present study, this system has been extended to include the quantitative analysis of the material-dependent osteoblast gene expression. Human foetal osteoblasts (hFOB 1.19) were cultured for 3 weeks on titanium surfaces of varying roughness, and on surfaces of chromium-cobalt-molybdenum alloy (CrCoMo). Using a real time RT-PCR technique, expressions of alkaline phosphatase, collagen 1 and osteocalcin were determined as parameters of osteoblast differentiation. In comparison with CrCoMo, differentiation was accelerated on titanium. While the smooth titanium surface leads to earlier cell growth, the rough surface induces more prolonged and stronger cell proliferation. Our results confirm at the molecular level the excellent clinical biocompatibility of titanium surfaces. The real-time RT-PCR provides a new method for the quantitative assessment of material-dependent osteoblastic differentiation.

[Angiogenesis and density of dendritic cells do not correlate with metachronous distant metastases after curative surgery of rectal carcinoma]

INTRODUCTION

Besides surgery, treatment of rectal cancer increasingly comprises (neo-)adjuvant strategies. To optimise the selection process for these therapy regimens especially in the field of cellular and molecular biology, new prognostic factors besides the established TNM system are being investigated.

METHODS

Retrospectively, two groups of patients (n = 2 x 85) with rectal carcinoma curatively treated by surgery alone were studied (median follow-up: 6.1 years). The patients were selected to be free of local disease, in order to exclude surgical influence. Patient groups were matched for age, gender, UICC stage and year of operation (1982-1991) and differed only in subsequent metachronous distant metastatic spread, the criterion to be studied. The factors to be investigated in uni- and multivariate analysis were angiogenesis, density of dendritic cells, grading, venous and lymphatic invasion.

RESULTS

Grading always proved to be the only significant prognostic factor (P < 0.0001). In univariate analysis, absent venous invasion also correlated significantly with increased disease-free survival (P = 0.0170).

CONCLUSIONS

Angiogenesis and density of dendritic cells in rectal cancer are not prognostic factors for metachronous distant metastasis and, therefore, cannot serve as selection parameters for adjuvant therapy.

Transcription of cytokeratins 8, 18, and 19 in bone marrow and limited expression of cytokeratins 7 and 20 by carcinoma cells: inherent limitations for RT-PCR in the detection of isolated tumor cells

The suitability of "real-time" quantitative reverse transcriptase polymerase chain reaction (RT-PCR) for the detection of isolated carcinoma cells in bone marrow was investigated by evaluating the expression of cytokeratin (CK)7, CK8, CK18, CK19, and CK20 in 17 gastrointestinal cancer cell lines, 64 control bone marrow specimens from noncancer patients, and 30 bone marrow specimens from patients with gastric or colorectal cancer. RT-PCR products for CK8 and CK18 were detected in all cancer cell lines, but only 16, 5, and 11 cell lines provided evidence for CK19, CK7, and CK20 transcription. Variable numbers of bone marrow specimens from noncancer patients demonstrated background transcription of CK8 (78.1%), CK18 (95.3%), CK19 (35.9%), CK20 (29.6%), and CK7 (16.7%). Maximal background transcription for CK8, CK18, and CK19 ranged from 52.2 to 56.1 copies/10(3) copies glyceraldehyde-3-phosphate dehydrogenase (GAPDH), the corresponding values of 0.06 and 0.76 copies for CK7 and CK20 being distinctly lower. When maximal background values were used as a threshold value to define positivity in tumor cell dilution experiments, sensitivity levels of one tumor cell in 10(4) bone marrow cells were determined for CK7 and CK20 RT-PCR assays. Maximal background expression values of the different CKs as obtained in the control series were exceeded once (CK20), twice (CK18 and CK19), and 18 times (CK7) in bone marrow specimens from cancer patients, with none of these specimens exceeding the maximal background expression value of CK8. We conclude that RT-PCR for CK8, CK18, and CK19 cannot be recommended for the detection of isolated tumor cells in bone marrow of cancer patients. On the other side, the limited number of gastric and colorectal cancer cell lines expressing CK7 and CK20 indicates that assay sensitivity for these CKs might be limited because of their selective expression by carcinoma cells.

[Detection of isolated tumor cells in bone marrow: methodological aspects. A critical re-appraisal and prospects]

Systemic dissemination of tumor cells occurring prior to the diagnosis or resection of the primary tumor is a prerequisite for relapse at distant sites and a major cause for death from cancer. Although detection of isolated tumor cells by sensitive immunocytochemical techniques is increasingly being considered as a clinically relevant prognostic factor, methodical objections including a questionable specificity of some of the antibodies applied, the heterogenity of the patient cohorts and the wide variation of the reported frequencies suggest that an independent prognostic impact of tumor cell detection in bone marrow at least for most of the tumor types still remains to be proven. When compared to non-morphological techniques immunocytochemistry is characterized by a lower false positive rate. So far a standarized application of this method still holds the most promise for clinical practice. Alternatively the genetic diagnosis of isolated tumor cells is hampered by a rather high false positive rate due to pseudogenes and illegitimate transcription. Appropriate negative controls in combination with a quantification of the PCR product are one possibility to overcome these difficulties. The clinical utility of genetic assays as a tool for the estimation of prognosis and management of cancer patients still remains an area of active investigation.

Interphase-FISH examinations in paraffin sections from benign, precancerous, and cancerous lesions of the skin and oral mucosa

In a preliminary pilot study centromeric probes for chromosomes #7, #8, #11, and #17 and two-colour-FISH were applied on interphase nuclei of 10 coded histologic thin sections obtained from archival paraffin material from precancerous lesions and malignant tumors of the mouth epithelium. Brilliant signals could be obtained in this material without any computerized processing. Among the ten coded probes, localized malignant areas within grade 2 leukoplakias could be detected by their increased number of aneusomic cells, as could the samples from carcinomas. In extension of this study archival paraffin material from 30 epithelial tumors of the skin were examined. The studied squamous cell and Bowen carcinomas were characterized by a large number of chromosomally aberrant subclones and gains of chromosomes were the prevailing finding. In contrast, keratoacanthomas showed distinctly less clonal variation, their majority exhibiting small, but significant clones with chromosome loss, particularly of chromosome #7, less distinctly of chromosome #17.