X-Ray Absorption Spectrum of the N_{2}

The x-ray absorption spectrum of N_{2}^{+} in the K-edge region has been measured by irradiation of ions stored in a cryogenic radio frequency ion trap with synchrotron radiation. We interpret the experimental results with the help of restricted active space multiconfiguration theory. Spectroscopic constants of the 1σ_{u}^{-1} ^{2}Σ_{u}^{+} state, and the two 1σ_{u}^{-1}3σ_{g}^{-1}1π_{g} ^{2}Π_{u} states are determined from the measurements. The charge of the ground state together with spin coupling involving several open shells give rise to double excitations and configuration mixing, and a complete breakdown of the orbital picture for higher lying core-excited states.

Electronic ground state of Ni2.

The Φ9/24 ground state of the Ni2+ diatomic molecular cation is determined experimentally from temperature and magnetic-field-dependent x-ray magnetic circular dichroism spectroscopy in a cryogenic ion trap, where an electronic and rotational temperature of 7.4±0.2 K was reached by buffer gas cooling of the molecular ion. The contribution of the spin dipole operator to the x-ray magnetic circular dichroism spin sum rule amounts to 7Tz=0.17±0.06µB per atom, approximately 11% of the spin magnetic moment. We find that, in general, homonuclear diatomic molecular cations of 3d transition metals seem to adopt maximum spin magnetic moments in their electronic ground states.

Decision analysis in the surgical treatment of patients with familial adenomatous polyposis: a Dutch-Scandinavian collaborative study including 659 patients.

BACKGROUND AND AIMS: The choice of colorectal surgery in patients with familial adenomatous polyposis lies between the morbidity of proctocolectomy and ileum-pouch-anal anastomosis (IPAA) and the mortality from rectal cancer after total colectomy and ileorectal anastomosis (IRA). The aims of the present study were: (1) to assess the risk of dying from rectal cancer after IRA, (2) to compare the life expectancy between patients with an IRA and those with an IPAA, and (3) to investigate whether regular endoscopic examination of the rectum leads to detection of cancer at an earlier stage. METHODS: Clinical and pathological data on 659 patients who underwent colectomy and ileorectal anastomosis were collected from four national polyposis registries-that is, in Denmark, Finland, Sweden, and the Netherlands. Data were analysed using survival analysis methods. Decision analysis was used to compare the life expectancy between patients with an IRA and those with an IPAA. RESULTS: A total of 47 patients developed rectal cancer after IRA. The risk of dying from rectal cancer was 12.5% (95% confidence interval 7.1--17.9%) by age 65. Compared with IRA, IPAA would lead to an increase in life expectancy of 1.8 years. Seventy five per cent of patients with rectal cancer had a negative rectoscopy within 12 months before the diagnosis. CONCLUSION: IRA is associated with substantial mortality due to rectal cancer. Follow up examinations of the rectum does not have sufficient preventive effect on morbidity and mortality of rectal cancer.

Endothelial capillaries chemotactically attract tumour cells.

Directional migration of capillaries towards tumour implants is generally assumed to be regulated by chemotaxis. Preliminary evidence has also been presented for the existence of a reverse chemotactic signalling pathway, with capillaries attracting tumour cells via paracrine factors. By using a variety of endothelial cell types and tumour cell lines, this study has systematically investigated chemotaxis between endothelial cells and tumour cells in two- and three-dimensional systems. Checkerboard analysis revealed faint attraction of human umbilical vein endothelial cells (HUVECs), but not porcine aortic endothelial cells (PAECs), by tumour cells. In reverse, both PAECs and HUVECs potently induced chemotactic migration of tumour cells. Using a microcarrier-based fibrin gel assay, directional migration of endothelial cells towards tumour cells was not observed. In reverse, tumour cells were strongly attracted by endothelial cells. Identification of endothelium-derived chemotactic molecules may provide a valuable approach for the treatment of tumour metastasis.

Ileorectal anastomosis is appropriate for a subset of patients with familial adenomatous polyposis.

BACKGROUND & AIMS: This study reevaluates the risk of rectal cancer and the frequency of subsequent proctectomy for nonmalignant causes in patients with familial adenomatous polyposis (FAP) who have undergone colectomy with ileorectal anastomosis (IRA). Potential risk factors for rectal cancer in this setting are also examined, and recommendations for the choice of surgical procedure are made. METHODS: The national polyposis registries in Denmark, Finland, The Netherlands, and Sweden included 659 patients undergoing surgery with IRA in 1940-1997. Kaplan-Meier analysis and Cox regression analysis were performed to evaluate cumulative risk, survival, and predictive risk factors. RESULTS: Rectal carcinoma was diagnosed in 47 patients, with a cumulative 40-year risk of 0.32. The cumulative risk according to chronologic age was 0.30 at age 60, and higher in patients undergoing surgery above age 25 (P = 0.0016). Chronologic age was the only independent risk factor (P = 0.0016). The cumulative 5-year survival rate after rectal carcinoma was 0.60. The apc mutation was known in 167 patients, of whom 7 had rectal cancer. The cumulative 40-year risk of secondary proctectomy was 0.70, and higher in patients with a mutation in codon 1250-1500 than outside this region (P = 0.005). However, all 7 rectal cancers were found in the latter group. None of the 18 patients with attenuated FAP (mutation in codon 0-200 or >1500) had a secondary proctectomy. CONCLUSIONS: IRA is recommended in (1) young patients with few rectal adenomas and a family history of a mild phenotype and (2) patients with attenuated FAP (a mutation in codon 0-200 or >1500), provided there is acceptance of life-long rectal surveillance. Patients with many rectal polyps and/or a family history of severe polyposis should be offered a restorative proctocolectomy with an ileal pouch-anal anastomosis.

[Combined nitroglycerin-heparin infusion in mesenteric venous thrombosis]. / Kombineret nitroglycerin-heparininfusion ved venøs mesenteriel trombose.

Surgical treatment of venous mesenterial thrombosis (VMT) may result in a short bowel-syndrome. We report the successful outcome of combined intravenous heparin and nitroglycerine in a case of VMT followed by a limited resection of small bowel.

Is screening for thyroid carcinoma indicated in familial adenomatous polyposis? The Leeds Castle Polyposis Group.

Forty-five polyposis patients with thyroid carcinoma constituted 1.2% of the patients in the Leeds Castle Polyposis Group database. The patients were diagnosed during 1959-1995; 44 were females at a median age of 25 years (range 10-40) and 37 (82%) had papillary carcinoma. At the end of 1995 only one patient (9%) had died from thyroid carcinoma, and the ten-year cumulative survival was 84% (95% confidence limits 72-97). Due to the low incidence of thyroid carcinoma in FAP and the good prognosis we do not recommend a regular thyroid screening in polyposis, as this is unlikely to result in a reduction of the mortality, but will only aggravate existing cancrophobia in these strained patients.

[Prognosis in familial adenomatous polyposis. Results from the Polyposis Registry]. / Prognosen ved familiaer adenomatøs polypose. Resultater fra polyposeregistret.

Regional and national polyposis registries have been established all over the world over last decades, with the aim to improve survival in patients with familial adenomatous polyposis (FAP). The Danish Polyposis Register was founded in 1971 and coordinates screening and prophylactic treatment. At the end of 1992 the register included 321 histologically verified FAP patients: 142/205 probands (69%) had colorectal cancer at the time of diagnosis of FAP versus only 2/116 call-up cases (2%). The 10-year cumulative crude survival was 94% among call-up cases versus only 41% among probands (p < 0.00001), and the survival increased significantly after establishment of the Polyposis Register in 1971. We conclude that centralized registration with identification and prophylactic examination of relatives at risk results in a substantial improvement of the prognosis.

The incidence rate of familial adenomatous polyposis. Results from the Danish Polyposis Register.

Based on the Danish Polyposis Register epidemiological calculations on familial adenomatous polyposis (FAP) were carried out. The mean annual incidence was 1.85 x 10(-6) during the years 1971-1992, and the prevalence increasing to about 32 x 10(-6) at the end of 1992. FAP patients constituted a decreased percentage of all Danish patients with colorectal cancer (0.07% in 1980-1992). The completeness of registration was 97% in 1983-1992. The results are similar to Finnish estimates based on the same direct method of calculation, and as both series are based on almost complete national polyposis registration in well-registered populations we regard our results to be close to the true incidence rate.

Centralized registration, prophylactic examination, and treatment results in improved prognosis in familial adenomatous polyposis. Results from the Danish Polyposis Register.

BACKGROUND: Over the last few decades numerous regional and national registers have been established all over the world with the aim of improving survival in familial adenomatous polyposis (FAP). The Danish Polyposis Register was founded in 1971 and coordinates the screening and subsequent prophylactic colectomy of FAP patients. METHODS: The crude cumulative survival in 321 patients (205 probands and 116 call-up cases) with verified FAP was calculated in accordance with the life-table method. RESULTS: At the time of diagnosis of FAP only 2 of 116 (2%) had colorectal cancer versus 142 of 205 probands (69%). The 10-year cumulative survival was 94% (95% confidence limits, 89-99) in call-up cases compared with only 41% (34-49) in probands (p < 0.00001), and survival improved significantly (p < 0.00001) after the establishment of the Danish Polyposis Register. CONCLUSION: The establishment of a centralized polyposis register has resulted in a substantial improvement of the prognosis in FAP.