Thermal and cold neutron phase-contrast radiography.

In this paper, we will discuss a phase-contrast imaging method that avoids the complications of interferometry to provide phase contrast in weakly absorbing samples. A transversely coherent neutron beam is used with the traditional radiography scheme. Images taken with this scheme show dramatic intensity variations due to sharp changes in the neutron wave refractive index. With some numerical processing these images may be used to reconstruct a quantitative phase radiograph of specimens imaged with this technique.     

Use of suture-mediated vascular closure devices for the management of femoral vein access after transcatheter procedures.

Groin complications remain the most common complication of cardiac catheterization procedures. While the use of closure devices is increasing for arterial sheaths, venous sheaths tend to be removed and hemostasis achieved with manual compression. We report our experience using Perclose suture-mediated vascular closure device to achieve hemostasis and early mobility in patients who have had venous access as part of their procedure. There were a total of 42 patients (21 males; average age, 63.5 years) studied. The majority of the patients had 7 Fr sheaths (24), with access sites of sheaths up to 14 Fr being closed with this technique. Two patients developed complications at the access site: one patient requiring rehospitalization for intravenous antibiotics because of late access site infection, and one patient with deep venous thrombosis and pulmonary emboli. We conclude that the use of the Perclose suture-mediated closure device for closure of femoral venous access sites is feasible and should be considered especially in patients with larger venous sheaths and those at increased risk of groin complications.     

Surveillance of duodenal polyps in familial adenomatous polyposis: progress report.

Familial adenomatous polyposis (FAP) is characterized by the presence of premalignant adenomas of the large and small bowel. Prophylactic colectomy deals with the risk for colon cancer, leaving duodenal cancer as the leading cause of death. Although most FAP patients have duodenal adenomas, only approximately 5% develop duodenal cancer. This study looks at progression of duodenal polyps with time. The outcome of endoscopic surveillance in the duodenum of 70 patients with familial adenomatous polyposis was determined. A mean of 40 months elapsed between endoscopies. Outcome was measured using video comparison and a staging system that includes histological assessment. Duodenal cancer developed in one patient, and was suspected in two others. The stage of duodenal polyposis worsened in another seven patients. When histology was ignored, comparison of video recordings in 52 patients showed a worsening in 21 (40%). In conclusion, further surveillance appears warranted so that patients at high risk for duodenal cancer might receive early treatment. Should slow progression of duodenal polyposis be shown to be associated with low risk, then most patients can be safely offered less frequent endoscopies than hitherto.     

Home ventilation in Northern Ireland.

Thirteen patients were identified as receiving assisted ventilation at home in Northern Ireland in 1994. Two patients have since died. An increasing number of patients are starting home ventilation, especially by nasal mask. Recognition of the needs of these patients and provision of care require further consideration.     

Adapting industry-style business model to academia in a system of Performance-based Incentive Compensation.

Performance-Based Incentive Compensation (PBIC) plans currently prevail throughout industry and have repeatedly demonstrated effectiveness as powerful motivational tools for attracting and retaining top talent, enhancing key indicators, increasing employee productivity, and, ultimately, enhancing mission-based parameters. The University of Arkansas for Medical Sciences (UAMS) College of Medicine introduced its PBIC plan to further the transition of the college to a high-performing academic and clinical enterprise. A forward-thinking compensation plan was progressively implemented during a three-year period.After the introduction of an aggressive five-year vision plan in 2002, the college introduced a PBIC plan designed to ensure the retention and recruitment of high-quality faculty through the use of uncapped salaries that reflect each faculty member's clinical, research, and education duties. The PBIC plan was introduced with broad, schoolwide principles adaptable to each department and purposely flexible to allow for tailor-made algorithms to fit the specific approaches required by individual departments.As of July 2006, the college had begun to reap a variety of short-term benefits from Phase I of its PBIC program, including increases in revenue and faculty salaries, and increased faculty morale and satisfaction.Successful implementation of a PBIC plan depends on a host of factors, including the development of a process for evaluating performance that is considered fair and reliable to the entire faculty. The college has become more efficient and effective by adopting such a program, which has helped it to increase overall productivity. The PBIC program continues to challenge our faculty members to attain their highest potential while rewarding them accordingly.     

Chronic glucocorticosteroid therapy impairs staphylococcal clearance from murine lungs.

Since the clearance of Staphylococcus aureus from murine lungs after aerosol exposure depends only on regional defense processes and does not require the recruitment of neutrophils or other systemic factors, we used this model for pulmonary clearance to evaluate the effect of chronic glucocorticosteroid therapy on intrinsic pulmonary defense responses. Mice treated with oral prednisolone for 2 or more weeks had delayed clearance of S. aureus at both 6 and 22 h after aerosol exposure. Mice treated with prednisolone for 1 week had delayed clearance at 22h, and mice treated for 2 days had normal clearance. In mice that had been treated for 2 weeks, clearance returned to normal after 2 weeks off therapy, but not after 1 week. Prednisolone did not appear to alter the number of phagocytes in bronchoalveolar spaces or their ingestion capacity. These results suggest that chronic steroid therapy can alter pulmonary clearance functions independent of any effect on immune or inflammatory responses.     

Location,identity, amount and serial entry of chloroplast DNA sequences in crucifer mitochondrial DNAs

Southern blot hybridization techniques were used to examine the chloroplast DNA (cpDNA) sequences present in the mitochondrial DNAs (mtDNAs) of two Brassica species (B. campestris and B. hirta), two closely related species belonging to the same tribe as Brassica (Raphanus sativa, Crambe abyssinica), and two more distantly related species of crucifers (Arabidopsis thaliana, Capsella bursa-pastoris). The two Brassica species and R. sativa contain roughly equal amounts (12–14 kb) of cpDNA sequences integrated within their 208–242 kb mtDNAs. Furthermore, the 11 identified regions of transferred DNA, which include the 5 end of the chloroplast psaA gene and the central segment of rpoB, have the same mtDNA locations in these three species. Crambe abyssinica mtDNA has the same complement of cpDNA sequences, plus an additional major region of cpDNA sequence similarity which includes the 16S rRNA gene. Therefore, except for the more recently arrived 16S rRNA gene, all of these cpDNA sequences appear to have entered the mitochondrial genome in the common ancestor of these three genera. The mitochondrial genomes of A. thaliana and Capsella bursa-pastoris contain significantly less cpDNA (5–7 kb) than the four other mtDNAs. However, certain cpDNA sequences, including the central portion of the rbcL gene and the 3 end of the psaA gene, are shared by all six crucifer mtDNAs and appear to have been transferred in a common ancestor of the crucifer family over 30 million years ago. 1n conclusion, DNA has been transferred sequentially from the chloroplast to the mitochondrion during crucifer evolution and these cpDNA sequences can persist in the mitochondrial genome over long periods of evolutionary time.     

TGF-beta1 regulates TGF-beta1 and FGF-2 mRNA expression during fibroblast wound healing.

AIMS: To evaluate the expression of transforming growth factor beta1 (TGF-beta1) and fibroblast growth factor 2 (FGF-2) mRNA in stromal cells in response to injury in the presence of either TGF-beta1 or FGF-2. It has been shown previously that heparan sulfate proteoglycans and FGF-2 are present transiently during wound repair in vivo and that an increase in TGF-beta1 mRNA is detected rapidly after injury. METHODS: Primary corneal fibroblasts were cultured to confluency, serum starved, and linear wound(s) were made in medium containing TGF-beta1 or FGF-2. TGF-beta1 and FGF-2 mRNA expression were evaluated using both northern blot analysis and in situ hybridisation. Both dose dependent and time course experiments were performed. Whole eye organ culture experiments were also carried out and growth factor expression was assessed. RESULTS: Injury and exogenous TGF-beta1 increased TGF-beta1 mRNA values. The increase in expression of FGF-2 mRNA was not detected until wound closure. In contrast, FGF-2 inhibited the expression of TGF-beta1. TGF-beta1 increased TGF-beta1 mRNA stability but did not alter that of FGF-2. Migration assay data demonstrated that unstimulated stromal cells could be activated to migrate to specific growth factors. CONCLUSIONS: TGF-beta1 specifically enhances cellular responsiveness, as shown by increased stability after injury and the acquisition of a migratory phenotype. These data suggest that there is an integral relation during wound repair between TGF-beta1 and FGF-2.