In vivo models for early development of colorectal liver metastasis.

In Europe, colorectal cancer is the second most prevalent form of cancer diagnosed. Globally each year, almost one million cases of colorectal cancer are registered and almost half a million deaths are attributed to this disease. This high mortality is associated with the development of liver metastases. For oncological advances to occur, accurate in vivo models are required to study colorectal cancer metastasis development. These models, by increasing our understanding of the early stages of colorectal liver establishment, will facilitate the development of novel therapeutic interventions and allow the clinical effects of these interventions to be studied. By analysis of current in vivo models for early development of colorectal liver metastasis, this review examines available methods of the tumour cell preparation, introduction and monitoring in vivo. An insight into the technical problems which can occur will be discussed. The implications of these different techniques on the resulting metastasis picture will be analysed. Existing in vivo models are assessed regarding the accuracy of the metastatic picture they portray.

An in vivo rat model for early development of colorectal cancer metastasis to liver.

At diagnosis of colorectal cancer, approximately 25% of the patients have established colorectal liver metastasis. Optimal management of disseminated disease requires therapies targeting multiple stages in hepatic colorectal cancer metastasis development. To facilitate this, biologically accurate in vivo models are required. Early colonic cancer liver metastases development was studied using BDIX and Sprague-Dawley rat strains with human HT29 and rat DHDK12 colonic cancer cell lines. Different cancer cell-host combinations were used. Rat DHDK12 was previously chemically induced in the BDIX rat. Real-time intra-vital microscopy was employed to analyse the early development of liver metastases in four groups (n = 6 per group) (HT29-BDIX, DHDK12-BDIX, HT29-SD and DHDK12-SD). Data were compared using one-way anova with Bonferroni's multiple comparison test. The total number of tumour cells visualized, adherent cells within the hepatic sinusoids, extravasated tumour cells and migration rates were significantly higher in the DHDK12-BDIX combination. Maximum number of visualized cells and maximum migration rate were also significantly higher in this group. No significant differences were observed in these experimental parameters among the other three groups or in the haemodynamic parameters among all groups. In conclusion, cancer cell line-host selection has a significant effect on early colonic cancer liver metastasis development.

Appendiceal mucocoeles and pseudomyxoma peritonei.

Mucocoele of the appendix occurs when obstruction of the appendiceal lumen results in mucus accumulation and consequent abnormal dilatation. The most important aetiology, from a surgical perspective, is either mucinous cystadenoma or cystadenocarcinoma. In the latter, a spontaneous or iatrogenic rupture of the mucocoele can lead to mucinous intraperitoneal ascites, a syndrome known as pseudomyxoma peritonei. Optimal management of mucoceles is achieved through accurate preoperative identification and subsequent careful resection. We report two cases and subsequently discuss the clinical presentation of mucocoeles, their association with pseudomyxoma peritonei and an optimal management of both conditions.

An unusual tumor presentation.

Germ cell cancer is the most common malignancy in men 15-35 years of age; 5% of malignant germ cell tumors are of extragonadal origin. The key to diagnosis and management is tumor histology. This point is highlighted in this case review. It also reinforces that germ cell tumor markers should be done in all young patients diagnosed with malignancy. We describe the case of a 21-year-old man who was diagnosed as having inoperable cancer of the ascending colon, which turned out to be extragonadal germ cell tumor after studies. This patient has responded very well to bleomycin, etoposide, and cisplatin chemotherapy.

Clinical potential of quantum dots.

Advances in nanotechnology have led to the development of novel fluorescent probes called quantum dots. Quantum dots have revolutionalized the processes of tagging molecules within research settings and are improving sentinel lymph node mapping and identification in vivo studies. As the unique physical and chemical properties of these fluorescent probes are being unraveled, new potential methods of early cancer detection, rapid spread and therapeutic management, that is, photodynamic therapy are being explored. Encouraging results of optical and real time identification of sentinel lymph nodes and lymph flow using quantum dots in vivo models are emerging. Quantum dots have also superseded many of the limitations of organic fluorophores and are a promising alternative as a research tool. In this review, we examine the promising clinical potential of quantum dots, their hindrances for clinical use and the current progress in abrogating their inherent toxicity.

An analysis of risk factors associated with failure of below knee amputations.

BACKGROUND: Below knee amputation (BKA) is often required in patients with critical limb ischemia. When such a procedure fails, an above knee revision (AKA) is required. This can cause further complications in this group of patients, who already have a high incidence of medical co-morbidities. METHODS: Case records of 47 patients (51 procedures performed) with BKA for peripheral vascular diseases during a 4-year period were reviewed. Clinical factors were analyzed using bi- and multi-variate analysis against the procedure outcome. Degree of social deprivation was evaluated with DEPCAT score in relation to amputation failure. Each arterial segment of the pre-operative arteriograms was scored based on a 3-point scoring system (0=normal, 1=stenosis, and 2=cclusion). With the assignment of an arbitrary weight for each segment, a total arterial score (TAS) was derived for each patient. RESULTS: Eighteen percent of BKA (n=9) failed. Absence of popliteal pulse (failure vs. success: 100% vs. 63%, P=0.04), calf rest pain (67% vs. 20%, P=0.01), combination of calf rest pain and feet tissue loss (CRPFTL; 67% vs. 3%, P=0.00), postoperative stump trauma (44% vs. 10%, P=0.03), and wound infection (WI; 89% vs. 26%, P=0.00) were factors associated with the failure of a BKA in bivariate analysis. Using multiple logistic regression, WI (OR=14) and CRPFTL (OR=47) were found to be independent predictors for the outcome of BKA. No statistical significance was found between the DEPCAT score and the failure rate. TAS was significantly higher in the failure group (median=17 vs. 9; P=0.00). CONCLUSIONS: This study suggests that CRPFTL and postoperative WI are predictor variables for the failure of a BKA. In addition, there is the potential role of arteriogram scoring in predicting the outcome of a BKA.