Characterization of a protozoan Phosducin-like protein-3 (PhLP-3) reveals conserved redox activity

We recently identified three novel thioredoxin-like genes in the genome of the protozoan parasite Plasmodium that belong to the Phosducin-like family of proteins (PhLP). PhLPs are small cytosolic proteins hypothesized to function in G-protein signaling and protein folding. Although PhLPs are highly conserved in eukaryotes from yeast to mammals, only a few representatives have been experimentally characterized to date. In addition, while PhLPs contain a thioredoxin domain, they lack a CXXC motif, a strong indicator for redox activity, and it is unclear whether members of the PhLP family are enzymatically active. Here, we describe PbPhLP-3 as the first phosducin-like protein of a protozoan organism, Plasmodium berghei. Initial transcription analysis revealed continuous low-level expression of pbphlp-3 throughout the complex Plasmodium life cycle. Attempts to knockout pbphlp-3 in P. berghei did not yield live parasites, suggesting an essential role for the gene in Plasmodium. We cloned, expressed and purified PbPhLP-3 and determined that the recombinant protein is redox active in vitro in a thioredoxin-coupled redox assay. It also has the capacity to reduce the organic compound tert-Butyl hydroperoxide (TBHP) in vitro, albeit at low efficiency. Sequence analysis, structural modeling, and site-directed mutagenesis revealed a conserved cysteine in the thioredoxin domain to be the redox active residue. Lastly, we provide evidence that recombinant human PhLP-3 exhibits redox activity similar to that of PbPhLP-3 and suggest that redox activity may be conserved in PhLP-3 homologs of other species. Our data provide new insight into the function of PhLP-3, which is hypothesized to act as co-chaperones in the folding and regulation of cytoskeletal proteins. We discuss the potential implications of PhLP-3 as a thioredoxin-target protein and possible links between the cellular redox network and the eukaryotic protein folding machinery

Does mixing acute medical admissions with burn patients increase infective complications from paediatric thermal injuries?

In the winter of 2005–2006, the management at our children's hospital elected to admit ‘overspill’ acute medical admissions to the ward used for plastic surgery and burns for logistical reasons. This study was conducted to assess the effects of that change on the incidence of infective complications in thermally-injured patients. Seventy-three patients were studied, 23 in the sample winter and 50 in the two preceding control winters. The data gathered included days on IV fluids and antibiotics, transfer to the Paediatric Intensive Care Unit (PICU), microbiology and a ‘septic signs score’ – based on pyrexia, irritability, diarrhoea/vomiting, wound colonization, bacteraemia. The outcomes studied were: the maximum ‘septic signs score’; patients with a score ≥3; wound colonization; PICU admission; days on antibiotics and IV fluids. A statistically significant increase in patients with septic episodes was demonstrated by an increase in the mean septic signs score (0.66–1.48, P = 0.044) and the number of patients with a score ≥3 (4–22%, P = 0.017). Other analysed variables did not reach statistical significance although the raw data suggested a trend. It was concluded that there is an association between mixing acute medical admissions with thermally-injured patients and an increase in the incidence of infective complications in the latter group

The impact of malignant nipple discharge cytology (NDc) in surgical management of breast cancer patients

BACKGROUND: The role of nipple discharge cytology (NDc) in the surgical management of breast cancer patients is unclear. We aimed: (i) to evaluate the effect of malignant NDc on the surgical approach to the nipple-areola complex, and (ii) to verify the association between malignant NDc and nipple malignancy. METHODS: We retrospectively analyzed a case series of 139 patients with NDc who underwent breast surgery. The clinical and histological findings, types of surgery with emphasis on nipple-areola complex amputation, immunohistochemical phenotypes of the carcinomas and measurements of the tumor-nipple distance were recorded. Additionally, in patients who showed HER2-positive lesions on definitive surgery, we evaluated the HER2 immunocytochemistry of the NDc smears. RESULTS: Thirty-two malignant and 107 benign/borderline NDc diagnoses were identified. All 32 malignant-NDc cases were histologically confirmed as malignant. Thirty borderline/benign-NDc cases were histologically diagnosed as malignant (sensitivity 58%). The majority of the patients with malignant NDc were treated with nipple-areola complex amputations in both the mastectomy and conservative surgery groups (P<0.001, chi251.77). Nipple involvement was strongly associated with HER2-positive ductal carcinoma in-situ (P<0.001, chi211.98). HER2 immunocytochemistry on the NDc revealed a 100% correlation with the immunocytochemistry performed on the surgical tissues. CONCLUSIONS: Malignant NDc influenced surgical management. The association of malignant NDc with nipple involvement is highly related to ductal carcinoma in-situ with HER2 overexpression. In case of HER2 positive NDc, nipple-areola complex involvement is more likely than in HER2 negative cases

Role of Histone Acetylation in the Stimulatory Effect of Valproic Acid on Vascular Endothelial Tissue-Type Plasminogen Activator Expression

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