The width of resection margins influences local recurrence in soft tissue sarcoma patients

BACKGROUND

Patients with soft tissue sarcoma (STS) being treated following the standardized guidelines can still not be guaranteed to remain free from local recurrence (LR). A complete tumour resection has been accepted as a major prognostic factor for LR. This retrospective study was designed to analyse the influence of two different classifications of resection margins (R-classification and UICC-classification) on LR in STS patients.

MATERIALS AND METHODS

Of 411 patients treated at our institution for STS, 265 were eligible for statistical analysis. Kaplan-Meier curves and Cox regression models were used to assess the impact of an R0 resection according to the R-classification (resection margin clear but allowing <1 mm) and according to the UICC-classification (minimal resection margin ≥1 mm) on LR.

RESULTS

Survival curves showed a lower LR rate for R0 resections in the UICC-classification, namely 1.3%, 12% and 12% as compared to 2.1%, 9.5% and 16.5% for the R-classification. In multivariate analysis calculated separately for each classification, R1 resection as defined by the R-classification (HR: 11.214; 95%CI: 2.394-52.517; p = 0.002) as well as by UICC-classification (HR: 15.634; 95%CI: 2.493-98.029; p = 0.003) remained significant.

CONCLUSION

In our study, margin status according to both classifications represents an independent prognostic factor for LR in patients with STS following curative surgery. Local control rates were superior after a minimal resection margin of 1 mm (R0 by UICC-classification) compared to R0 resections after the R-classification.

PO-63 - Exhausted platelets in cancer patients with high risk of venous thromboembolism and poor prognosis

INTRODUCTION

Platelets play a crucial role in cancer development, progression and metastatic spread of malignancy. In vitro data show that cancer cells have the ability to activate platelets, and clinical studies found increased levels of platelet activation markers in cancer patients. Moreover, platelets are thought to be involved in the development of venous thromboembolism (VTE) in cancer patients, a frequent complication of malignant disease associated with high morbidity and mortality.

AIM

In this study, we aimed to examine the activation status of platelets in cancer patients and investigate the association with risk of future venous thromboembolism (VTE) and mortality.

MATERIALS AND METHODS

In a prospective observational cohort study of cancer patients we measured pre-chemotherapy platelet P-selectin and glycoprotein (GP) IIb/IIIa expression and monocyte-platelet aggregates (MPA) in vivo and in response to ex vivo stimulation of the platelet activation receptors protease-activated receptor (PAR) -1, -4, and GPVI by whole blood flow cytometry. Primary and secondary endpoints of the study were occurrence of objectively confirmed VTE and death during 2-year follow-up, respectively.

RESULTS

Out of 62 patients (median age [interquartile range, IQR]: 63 [54-70] years, 48% female) with cancers of the pancreas (n=19), lung (n=18), brain (n=14), colon (n=8) and stomach (n=3), 9 (14.5%) developed VTE and 32 (51.6%) died. P-selectin, activated GPIIb/IIIa expression and MPA formation did not significantly differ between tumor sites (Kruskal Wallis test). Reduced platelet responsiveness to PAR-1 and GPVI stimulation was associated with a higher risk of VTE (hazard ratio [HR] per decile increase in %P-selectin positive platelets: 0.73 [95% confidence interval: 0.56-0.92, p=0.007] and 0.77 [0.59-0.98, p=0.034], respectively; Table 1). Further, lower platelet P-selectin and activated GPIIb/IIIa expression in vivo and in response to PAR-1, -4 and GPVI stimulation, but not MPA formation, were associated with a higher risk of death (Table 1).

CONCLUSIONS

Cancer patients with a poor prognosis had degranulated platelets, presumably as a consequence of previous activation. Our data suggest that platelets' continuous activation and thus exhaustion is involved in cancer-associated VTE and cancer mortality.

Validated modeling for German white wine varietal authentication based on headspace solid-phase microextraction online coupled with gas chromatography mass spectrometry fingerprinting

An untargeted analytical approach combined with chemometrics using the volatiles of German white wine was investigated regarding the usefulness for verifying botanical origin. A total of 198 wine samples of Riesling, Müller-Thurgau, Silvaner, Pinot Gris, and Pinot Blanc were examined applying headspace solid-phase microextraction online coupled with gas chromatography mass spectrometry. The resultant three-dimensional raw data were processed by available metabolomics software. After data treatment, a partial least-squares discriminant analysis (PLS-DA) model was validated. External samples were correctly classified for 97% Silvaner, 93% Riesling, 91% Pinot Gris/Blanc, and 80% Müller-Thurgau. This model was related to monoterpenoids, C13-norisoprenoids, and esters. Further, 100% prediction for a two-class model of Riesling versus Pinot Gris/Blanc was confirmed by 74 additional samples measured independently. Hence, the strategy applied was, in particular, reliable and relevant for white wine varietal classification. In addition, the superior classification performance of the Riesling class was revealed.

Bacteremia due to Pseudomonas aeruginosa: results from a 3-year national study in the Slovak Republic

Risk factors, mortality and antimicrobial susceptibility of Pseudomonas aeruginosa bacteremias isolated from 148 patients from all University Hospitals in Slovakia were analyzed. Only 1.2% of 169 strains of P. aeruginosa were resistant to meropenem, 4.1% to piperacillin/tazobactam, 7.7% to ceftazidime as well as cefepime and 12% to amikacin. More than 30% of P. aeruginosa were resistant to ciprofloxacin. Our analysis of risk factors for antimicrobial resistance to the particular antimicrobials, indicated no difference in risk factors and outcome in cases infected with P. aeruginosa bacteremias resistant to amikacin, piperacillin/tazobactam or ceftazidime in comparison to episodes caused by P. aeruginosa due to susceptible isolates. When comparing risk factors for P. aeruginosa bacteremia in children vs. adults, cancer vs. non-cancer patients, several differences in risk factors were observed. Neither antimicrobial resistance to amikacin, ceftazidime or piperacillin/tazobactam, nor appropriateness of therapy according to two separate analyses were associated with better outcome.

AF6 negatively regulates Rap1-induced cell adhesion

AF6 is involved in the connection of membrane-associated proteins to the actin cytoskeleton. It binds to Ras-like small GTPases and is suggested to be an effector of both Ras and Rap. Here we show that knockdown of AF6 in T cells by RNA interference enhanced Rap1-induced integrin-mediated cell adhesion, whereas overexpression of AF6 had the opposite effect. Interestingly, AF6-induced inhibition of cell adhesion correlated with an increase in RapGTP levels. Like AF6, protein KIAA1849 contains a Ras association domain and interacted with Rap1. However, KIAA1849 did not inhibit Rap1-induced cell adhesion. We concluded that AF6 is a negative regulator of Rap-induced cell adhesion. We proposed that AF6 inhibits Rap-mediated cell adhesion by sequestering RapGTP in an unproductive complex and thus prevents the interaction of Rap1 not only with effectors that mediate adhesion but also with Rap GTPase-activating proteins. Thus, AF6 may buffer RapGTP in resting T cells and maintain them in a non-adherent state.

Detecting cAMP-induced Epac activation by fluorescence resonance energy transfer: Epac as a novel cAMP indicator

Epac1 is a guanine nucleotide exchange factor for Rap1 that is activated by direct binding of cAMP. In vitro studies suggest that cAMP relieves the interaction between the regulatory and catalytic domains of Epac. Here, we monitor Epac1 activation in vivo by using a CFP-Epac-YFP fusion construct. When expressed in mammalian cells, CFP-Epac-YFP shows significant fluorescence resonance energy transfer (FRET). FRET rapidly decreases in response to the cAMP-raising agents, whereas it fully recovers after addition of cAMP-lowering agonists. Thus, by undergoing a cAMP-induced conformational change, CFP-Epac-YFP serves as a highly sensitive cAMP indicator in vivo. When compared with a protein kinase A (PKA)-based sensor, Epac-based cAMP probes show an extended dynamic range and a better signal-to-noise ratio; furthermore, as a single polypeptide, CFP-Epac-YFP does not suffer from the technical problems encountered with multisubunit PKA-based sensors. These properties make Epac-based FRET probes the preferred indicators for monitoring cAMP levels in vivo.

[Endoscopic, pathologic-anatomic and histologic findings in the bovine teat. 2. Changes in the area of Fürstenberg's rosette]

In the present study endoscopically diagnosed changes of the Fürstenberg's rosette were examined histologically. For this purpose the teats of 200 slaughtered cows were inspected. In 19 cases proliferations in the region of the Fürstenberg's rosette were found. Additionally, tissue samples were taken from the Fürstenberg's rosette of 26 cows which showed milk flow disorders due to stenoses of this part of the teat. Teats of slaughtered cows as well as biopsy specimens were fixed in 5% formaldehyde and embedded in paraffin and in plastic. All specimens were stained according to H.E., Giemsa and Turnbull, respectively. Histologically, the proliferations of the Fürstenberg's rosette consisted of fibrovascular tissue (granulation tissue) covered by keratinized squamous epithelium (teat canal epithelium) in eleven cases. In the other cases double-layered cuboid epithelium (cisternal epithelium) was found additionally. The formation of granulation tissue and deposition of blood pigment was observed exclusively in areas covered by stratified epithelium. Therefore a traumatic lesion of the teat canal was supposed to be the cause of the histological findings. In contrast to several reports in the literature, however, no indications of an inversion of the teat canal epithelium were found. On the basis of these findings, the hitherto assumed idea of pathogenesis of proliferations of the Fürstenberg's rosette was modified and a new pathogenesis pattern was developed.

[Endoscopic, pathologic-anatomic and histologic findings in the bovine teat. 1. Changes in the area of the teat cistern in slaughtered cows]

In the present study 795 teats of slaughtered cows were examined endoscopically. Teats which showed lesions were examined histologically. Abnormalities were detected endoscopically in 37 teats. In five cases red discolorations were observed. Histologically these alterations proved to be fresh bleedings within the fibromuscular layer of the teat cistern. Thirteen teats showed yellowish discolorations of the cistern surface. Three of these cases could not be cleared up histologically. In the other cases moderate or severe blood pigment deposition (n = 10) or severe fibrosis (n = 3) of the fibromuscular layer were found. Neither fresh bleeding nor severe blood pigment deposition was found in teats with normal coloured epithelium of the cistern. Cistern surface was smooth in 18 cases, whereas in 19 cases nodules were found. Histologically all nodules consisted of fibrovascular tissue ("granulation tissue") covered with cisternal epithelium. Detailed histological examinations, however, revealed considerable morphological variations regarding the overlying epithelium, the extent and kind of cellular infiltration, the extent of angioplasia and fibroplasia as well as fresh bleedings or deposition of blood pigment in the underlying fibrovascular tissue in some cases. It was concluded, that teat endoscopy enables a differentiation between fresh and old bleedings according to the coloration of the cisternal surface. Nodular proliferations of the cistern surface generally consists of fibrovascular ("granulation") tissue. Further histological details, however, and thus possible information about the pathogenesis of the lesions cannot be assessed endoscopically.

The role of Rap1 in integrin-mediated cell adhesion

Rap1 is a member of the Ras-like small GTPases. Originally the protein was identified in a genome-wide screen for suppressors of Ras transformation, but the mechanism of this reversion remained elusive. We have investigated the signalling function of Rap1. We observed that Rap1 is activated by a large variety of stimuli, including growth factors, neurotransmitters and cytokines. Common second messengers like cAMP, diacylglycerol and calcium are mediators of this activation. These messengers activate guanine nucleotide exchange factors (GEFs), the most notable of which is Epac (exchange protein directly activated by cAMP). However, the downstream effectors of Rap1 are less clear. Although direct connections of Rap1 with the serine/threonine kinases Raf1 and B-raf have been reported, we were unable to find functional evidence for an interaction of endogenous Rap1 signalling with the Raf/extracellular-signal-regulated kinase (ERK) pathway. Instead we observe a clear connection of Rap1 with inside-out signalling to integrins. Indeed, introduction of a constitutively active Rap1 as well as Epac induces integrin-mediated cell adhesion, whereas inhibition of Rap1 signalling by the introduction of Rap1GAP (GTPase-activating protein) inhibits inside-out activation of integrins. More importantly, activation of a G(s)-protein-coupled receptor results in integrin-mediated cell adhesion, by a pathway involving Epac and Rap1. From these results, we conclude that one of the functions of receptor-induced Rap1 activation is inside-out regulation of integrins.

Escherichia coli isolates from young calves in Bavaria: in vitro susceptibilities to 14 anti-microbial agents

During the occasional testing of Escherichia coli from faecal samples of young calves we observed multi-resistant isolates. Because of the significance of E. coli as an indicator bacterium for resistance trends we tested E. coli populations of young calves over a longer period. Here we present the results of a retrospective study comparing isolates from 1998 to 2000. Moreover, we compared, in a clinical study, the resistance rates of E. coli populations from 67 hospitalized calves both before and after hospitalization (with or without anti-microbial therapy), and with their anamnestic data of antibiotic usage. The highest resistance rates were found to be more than 80% for tetracyclines, ampicillin, sulfonamide/trimethoprim combinations, and chloramphenicol. A significant increase or decrease over the years was not observed. In analysing the data of hospitalized calves, an increase of resistance to some anti-microbials had to be registered that seemed to be connected with the selective pressure due to agents used in the clinic. In comparing anamnestic data and resistance rates it became obvious that reliable data are not easily available and that a number of potential anti-microbial influence factors have to be taken into account.

[Preoperative computerized tomography diagnosis of fractures of the tibial plateau]

Within the last decade computed tomography has become an important instrument for skeletal diagnosis. In this study the value of helical CT-scan was compared with plan X-rays and conventional tomography in 45 patients having sustained an intraarticular tibia plateau fracture. Between plan roentgenogramms and CT-scan the fracture classification according to the AO-classification was changed in 40% of all patients, in 39 cases the amount of impression or dislocation increased with a mean of 4.2 mm. Especially tiny fragments were better visible and therefore responsible for the shift of many B1 fractures to group B3. The difference between conventional tomography and computed tomography was less impressive, a change of fracture classification could be observed in only 6.7% of all cases.

Aetiology of reduced milk ejection in cows after transport and the use of a long-acting analogue of oxytocin for prophylaxis

Milk flow was recorded in 21 cows for three days after they were admitted to a large animal hospital. When the spontaneous flow of milk had stopped, a physiological dose (1 iu) of oxytocin was administered intravenously. Five of the cows were, in addition, treated with 0.35 mg of a long-acting analogue of oxytocin (carbetocin) one hour before the first milking after they were admitted. In the 16 cows not treated with carbetocin, only about 30 per cent of the total milk yield was released spontaneously on the first day, and the injection of 1 iu of oxytocin released approximately another 60 per cent of the total milk yield. On the second day, the proportion of the total milk yield released spontaneously increased and the fraction released after the injection of 1 iu oxytocin decreased. In contrast, the five cows treated with carbetocin released on average 94 per cent of the total milk yield spontaneously during the first milking.

Some dietary fibers reduce the absorption of carotenoids in women

Dietary fiber may be partly responsible for the lower bioavailability of carotenoids from food than from purified supplements. Due to the lack of detailed information available, we investigated the effects of different kinds of dietary fiber on the absorption of carotenoids and alpha-tocopherol. Six healthy young women received an antioxidant mixture consisting of beta-carotene, lycopene, lutein, canthaxanthin and alpha-tocopherol together with a standard meal. The meal did not contain additional dietary fiber or was enriched with pectin, guar, alginate, cellulose or wheat bran (0. 15 g. kg body weight(-1)). The increases in plasma carotenoid and alpha-tocopherol concentrations were followed over 24 h, and the areas-under-curves (AUC(24h)) were calculated. The mean AUC(24h) of beta-carotene was significantly (P < 0.05) reduced by the water-soluble fibers pectin, guar and alginate with a mean decrease of 33-43%. All tested fibers significantly reduced the AUC(24h) of lycopene and lutein by 40-74% (P < 0.05). The dietary fiber effect on the AUC(24h) of canthaxanthin was almost significant (P = 0.059) and there was no effect on the AUC(24h) of alpha-tocopherol. We conclude that the bioavailability of beta-carotene, lycopene and lutein given within a mixed supplement is markedly reduced by different kinds of dietary fiber.

Dietary fiber reduces the antioxidative effect of a carotenoid and alpha-tocopherol mixture on LDL oxidation ex vivo in humans

BACKGROUND

Antioxidant concentrations in low density lipoproteins (LDL) are an important determinant for their susceptibility to oxidation and can be modulated by dietary intake.

AIM OF THE STUDY

In the present study, the influence of dietary fiber on the antioxidant enrichment and the oxidation resistance of LDL after antioxidant supplementation is investigated.

METHOD

An antioxidant supplement consisting of beta-carotene, lycopene, lutein, canthaxanthin and alpha-tocopherol was given to six young women together with a standard meal. Using a cross-over study design, each subject received the standard meal without additional dietary fiber and enriched with pectin, guar, or cellulose in a random order. To determine the resistance of LDL against copper ion-induced oxidation, the formation of conjugated dienes was measured.

RESULTS

Eight, 10, and 24 hours after antioxidant supplementation the isolated LDL revealed significantly (p < 0.05) increased antioxidant concentrations; addition of pectin, guar, or cellulose to the meal depressed this increase. Concomitantly, the observed increase in the resistance of LDL against oxidation (measured as lag phase) was lower with dietary fiber supplementation than that found without. On average, pectin, guar, and cellulose reduced the increase of the lag phase (measured without addition of dietary fiber) by 38%, 22%, and 18%, respectively.

CONCLUSIONS

These results indicate that dietary fiber supplementation decreases the antioxidative effect of a supplement consisting of carotenoids and alpha-tocopherol in LDL, an effect that is likely to be mediated by a reduced bioavailability of these antioxidants in the gut.

Secretion of interferon-tau by bovine embryos in long-term culture: comparison of in vivo derived, in vitro produced, nuclear transfer and demi-embryos

Interferon-tau (IFNtau) is the pregnancy recognition signal of bovine embryos, inhibiting luteolysis. We studied trophoblastic growth and IFNtau secretion of embryos with different developmental potential, i.e., in vivo derived and in vitro produced embryos, cloned embryos and demi-embryos, to evaluate if the ability of secreting IFNtau might be responsible for differences in pregnancy rates after transfer of these categories of embryos to recipients. Day 8 embryos of excellent quality were individually placed in microdrops of buffalo rat liver cell-conditioned medium and maintained for up to 23 days. Embryos were observed on Days 11, 15, 19 and 23, the mean diameter (2r) of attached and spherical embryos was measured, and their trophoblastic area was calculated as r2pi or 4r2pi, respectively. Simultaneously, medium was changed and the IFNtau levels of conditioned media were determined using a bioassay of antiviral activity. Trophoblastic area was smaller (P < 0.05) in demi-embryos than in all other groups, which exhibited similar trophoblastic growth until Day 19. However, on Day 23 trophoblastic area of in vivo derived embryos was more than twice (P < 0.05) as large as those of in vitro produced and nuclear transfer (NT) embryos. IFNtau levels increased only slowly with time in culture of demi-embryos. By contrast, the level of IFNtau doubled from Day 11 to Day 15 in conditioned media from all other groups of embryos. The linear increase in IFNtau production of vivo and in vitro derived embryos continued until the end of the culture period, whereas conditioned media from NT embryos contained significantly (P < 0.05) less IFNtau activity on Days 19 and 23 than those of the former two groups. Our results demonstrate different capabilities of secreting IFNtau for in vivo derived and in vitro produced embryos vs. NT and demi-embryos, which may--at least part--be responsible for the differences in pregnancy rates after transfer to recipients.