Five-year results of surgical colorectal cancer treatment in rural Australia.

Background: The incidence of colorectal cancer in Australia is among the highest worldwide. We investigate whether similar treatment results for colorectal cancer can be achieved in rural surgery as reported from metropolitan centres.

Methods: Retrospective analysis of prospectively collected follow-up data in a rural surgical centre in South Australia has been carried out.

Laparoscopic cholecystectomy--comparison of early postoperative results in an Australian rural centre and a German university hospital.

Background: Laparoscopic cholecystectomy is the treatment of choice for symptomatic gallstone disease. Cultural as well as organisational differences can result in significant variations of postoperative length of stay. AIM OF THE PRESENT STUDY: The aim of this study is to evaluate whether differences in postoperative length of stay and early postoperative outcome can be observed by comparison of an Australian rural centre and a German university hospital.

Rac1 GTPase and the Rac1 exchange factor Tiam1 associate with Wnt-responsive promoters to enhance beta-catenin/TCF-dependent transcription in colorectal cancer cells.

Background: beta-catenin is a key mediator of the canonical Wnt pathway as it associates with members of the T-cell factor (TCF) family at Wnt-responsive promoters to drive the transcription of Wnt target genes. Recently, we showed that Rac1 GTPase synergizes with beta-catenin to increase the activity of a TCF-responsive reporter. This synergy was dependent on the nuclear presence of Rac1, since inhibition of its nuclear localization effectively abolished the stimulatory effect of Rac1 on TCF-responsive reporter activity.

Assessing evidence for a pervasive alteration in tropical tree communities.

In Amazonian tropical forests, recent studies have reported increases in aboveground biomass and in primary productivity, as well as shifts in plant species composition favouring fast-growing species over slow-growing ones. This pervasive alteration of mature tropical forests was attributed to global environmental change, such as an increase in atmospheric CO2 concentration, nutrient deposition, temperature, drought frequency, and/or irradiance. We used standardized, repeated measurements of over 2 million trees in ten large (16-52 ha each) forest plots on three continents to evaluate the generality of these findings across tropical forests.

Post-operative critical care and outcomes of limb replantation: experience in a developing country.

Replantation is the treatment of choice for traumatic amputation. Its success rates vary, reaching 80% in world's best centres. This study analyses management practices of replantation in a regional centre in a developing country.

Suppression of nuclear Wnt signaling leads to stabilization of Rac1 isoforms.

The Rac1 GTPase contains a functional nuclear localization signal (NLS) and destruction box sequence in the C-terminal polybasic region. It has been postulated that these two regulatory sequences may function together, enabling Rac1 to participate in nuclear signaling pathways that ultimately target it for degradation. We have previously shown that the NLS activity of Rac1 and the Rac1b splice variant is essential for Wnt pathway activation.

Activation of tumor-specific splice variant Rac1b by dishevelled promotes canonical Wnt signaling and decreased adhesion of colorectal cancer cells.

Rac1b is a tumor-specific splice variant of the Rac1 GTPase that displays limited functional similarities to Rac1. We have shown previously a novel cross-talk between Rac1 and beta-catenin, which induces canonical Wnt pathway activation in colorectal cancer cells. This prompted us to investigate if Rac1b, frequently overexpressed in colon tumors, contributes to Wnt pathway dysregulation.

The importance of demographic niches to tree diversity.

Most ecological hypotheses about species coexistence hinge on species differences, but quantifying trait differences across species in diverse communities is often unfeasible. We examined the variation of demographic traits using a global tropical forest data set covering 4500 species in 10 large-scale tree inventories. With a hierarchical Bayesian approach, we quantified the distribution of mortality and growth rates of all tree species at each site.

Comparing tropical forest tree size distributions with the predictions of metabolic ecology and equilibrium models.

Tropical forests vary substantially in the densities of trees of different sizes and thus in above-ground biomass and carbon stores. However, these tree size distributions show fundamental similarities suggestive of underlying general principles. The theory of metabolic ecology predicts that tree abundances will scale as the -2 power of diameter.

Cross-talk between Rac1 GTPase and dysregulated Wnt signaling pathway leads to cellular redistribution of beta-catenin and TCF/LEF-mediated transcriptional activation.

Aberrant activation of the Wnt pathway is observed in numerous cancers, and is particularly important in colon cancer. We demonstrate that Rac1 GTPase can significantly increase the signaling activity of beta-catenin in cells with inherent dysregulation of the canonical Wnt signaling pathway. Expression of dominant-negative (N17)Rac1 mutant in colon cancer cells caused a marked inhibition of Wnt signaling, as determined by the TCF/LEF-responsive (TOPFLASH) transcription assay.

STK11/LKB1 germline mutations are not identified in most Peutz-Jeghers syndrome patients.

Germline mutations of the STK11 gene mapped to chromosome 19p13.3 are responsible for Peutz Jeghers syndrome (PJS), a dominant disorder associated with characteristic gastrointestinal hamartomatous polyps and a predisposition to various cancers. We conducted a detailed investigation of germline STK11 alterations by protein truncation test and genomic DNA sequence analysis in ten unrelated PJS families.

Implementation of surgical audit in Pakistan.

Unlabelled: Surgical audit, while extensively practised in the West, is still widely believed an impossible attainment in developing countries owing to the high cost and technology required to implement it. It is thus a poorly understood and rarely practised exercise in these countries. In this article we attempt to demonstrate the usefulness and feasibility of implementing audit in the setting of a developing country using personal computers (PCs) with simple, inexpensive and easily available software.

Extended indications for polypropylene mesh closure of the abdominal wall.

Over a two-year period (1982-1984) polypropylene (Marlex) mesh was used without closing the abdominal wound in 21 patients judged clinically likely to require further abdominal exploration. A total of 43 meshes were implanted. All 21 patients had more than one major laparotomy, median 3 laparotomies (range 2-7) for drainage of pus (76 per cent) and/or intestinal leakage (67 per cent).