Experimental study of delivery of humidified-warm carbon dioxide during open abdominal surgery.

BACKGROUND: The aim of this study was to monitor the effect of humidified-warm carbon dioxide (HWCO2 ) delivered into the open abdomen of mice, simulating laparotomy. METHODS: Mice were anaesthetized, ventilated and subjected to an abdominal incision followed by wound retraction. In the experimental group, a diffuser device was used to deliver HWCO2 ; the control group was exposed to passive air flow. In each group of mice, surgical damage was produced on one side of the peritoneal wall. Vital signs and core temperature were monitored throughout the 1-h procedure. The peritoneum was closed and mice were allowed to recover for 24 h or 10 days. Tumour cells were delivered into half of the mice in each cohort. Tissue was then examined using scanning electron microscopy and immunohistochemistry. RESULTS: Passive air flow generated ultrastructural damage including mesothelial cell bulging/retraction and loss of microvilli, as assessed at 24 h. Evidence of surgical damage was still measurable on day 10. HWCO2 maintained normothermia, whereas open surgery alone led to hypothermia. The degree of tissue damage was significantly reduced by HWCO2 compared with that in controls. Peritoneal expression of hypoxia inducible factor 1α and vascular endothelial growth factor A was lowered by HWCO2 . These effects were also evident at the surgical damage sites, where protection from tissue trauma extended to 10 days. HWCO2 did not reduce tumorigenesis in surgically damaged sites compared with passive air flow. CONCLUSION: HWCO2 diffusion into the abdomen in the context of open surgery afforded tissue protection and accelerated tissue repair in mice, while preserving normothermia. Surgical relevance Damage to the peritoneum always occurs during open abdominal surgery, by exposure to desiccating air and by mechanical trauma/damage owing to the surgical intervention. Previous experimental studies showed that humidified-warm carbon dioxide (HWCO2 ) reduced peritoneal damage during laparoscopic insufflation. Additionally, this intervention decreased experimental peritoneal carcinomatosis compared with the use of conventional dry-cold carbon dioxide. In the present experimental study, the simple delivery of HWCO2 into the open abdomen reduced the amount of cellular damage and inflammation, and accelerated tissue repair. Sites of surgical intervention serve as ideal locations for cancer cell adhesion and subsequent tumour formation, but this was not changed measurably by the delivery of HWCO2 .

Intestinal-specific activatable Myb initiates colon tumorigenesis in mice.

Transcription factor Myb is overexpressed in most colorectal cancers (CRC). Patients with CRC expressing the highest Myb are more likely to relapse. We previously showed that mono-allelic loss of Myb in an Adenomatous polyposis coli (APC)-driven CRC mouse model (Apc(Min/+)) significantly improves survival. Here we directly investigated the association of Myb with poor prognosis and how Myb co-operates with tumor suppressor genes (TSGs) (Apc) and cell cycle regulator, p27. Here we generated the first intestinal-specific, inducible transgenic model; a MybER transgene encoding a tamoxifen-inducible fusion protein between Myb and the estrogen receptor-α ligand-binding domain driven by the intestinal-specific promoter, Gpa33. This was to mimic human CRC with constitutive Myb activity in a highly tractable mouse model. We confirmed that the transgene was faithfully expressed and inducible in intestinal stem cells (ISCs) before embarking on carcinogenesis studies. Activation of the MybER did not change colon homeostasis unless one p27 allele was lost. We then established that MybER activation during CRC initiation using a pro-carcinogen treatment, azoxymethane (AOM), augmented most measured aspects of ISC gene expression and function and accelerated tumorigenesis in mice. CRC-associated symptoms of patients including intestinal bleeding and anaemia were faithfully mimicked in AOM-treated MybER transgenic mice and implicated hypoxia and vessel leakage identifying an additional pathogenic role for Myb. Collectively, the results suggest that Myb expands the ISC pool within which CRC is initiated while co-operating with TSG loss. Myb further exacerbates CRC pathology partly explaining why high MYB is a predictor of worse patient outcome.

Musculoskeletal disorder related to the work of doctors who perform medical invasive evaluation.

BACKGROUND: Experts in medical invasive evaluations, like colonoscopy, could be exposed to ergonomic risks during their work. Little attention has been given to these spectrum of occupational health. Its aimed to analyze possible clinical problems related to upper limb of physicians who perform those exams. METHODS: Cross-sectional study in a health service in Sao Paulo, Brazil. For evaluation of the workplace of the colonoscopist physician were applied two tools: Couto's check list and Sue Rodgers Method. The results direct the potential risk to upper limb injuries. RESULTS: The procedure is done and the final report is issued. There are no mandatory pauses during workday. The dominant hand holds the tube insertion with pincer movement during the exam, digital prehension being necessary at times. For this activity the employee has to use some strength. Couto's check list indicates a significant biomechanical factor. Sue Rodgers's Method states high ergonomic risk for dominant hand/wrist/fingers. CONCLUSION: The main risk for the development of health disorders are associated with the use of force and repetitive movements of hands. The adoption of regular breaks to recover most of the structures required is recommended.

Many parallel losses of infA from chloroplast DNA during angiosperm evolution with multiple independent transfers to the nucleus.

We used DNA sequencing and gel blot surveys to assess the integrity of the chloroplast gene infA, which codes for translation initiation factor 1, in >300 diverse angiosperms. Whereas most angiosperms appear to contain an intact chloroplast infA gene, the gene has repeatedly become defunct in approximately 24 separate lineages of angiosperms, including almost all rosid species. In four species in which chloroplast infA is defunct, transferred and expressed copies of the gene were found in the nucleus, complete with putative chloroplast transit peptide sequences. The transit peptide sequences of the nuclear infA genes from soybean and Arabidopsis were shown to be functional by their ability to target green fluorescent protein to chloroplasts in vivo. Phylogenetic analysis of infA sequences and assessment of transit peptide homology indicate that the four nuclear infA genes are probably derived from four independent gene transfers from chloroplast to nuclear DNA during angiosperm evolution. Considering this and the many separate losses of infA from chloroplast DNA, the gene has probably been transferred many more times, making infA by far the most mobile chloroplast gene known in plants.

Bone mineral density and its association with inherited protein S deficiency.

Two unrelated children with thrombotic disease associated with inherited protein S deficiency and osteopenia have been identified. Measurement of protein S yielded markedly reduced levels of free protein S (less than 12.5%) in both propositi, a normal level of total protein S (79%) in propositus #1, and markedly reduced level of total protein S (34%) in propositus #2. Bone densitometry measurements of the two children revealed trabecular vertebral bone mineral content below two standard deviations. This defect is associated with vertebral body compression fractures in propositus #2. Therefore, it is hypothesized that protein S deficiency is associated with abnormalities of bone mineral density.