Incidence and survival in patients with pharyngeal cancer in northern Finland

A population-based survey was conducted in northern Finland in order to study the incidence rate and survival in patients with pharyngeal cancer diagnosed between 1986 to 1996. A total of 95 new patients with hypopharyngeal, oropharyngeal or nasopharyngeal cancers were identified. The overall age-adjusted incidence rates (per 100,000 years) were 1.28 in men and 0.60 in women, giving an overall incidence rate of 0.89. Most of the tumours were diagnosed at stage IV, and the median disease-specific survival times were 27.6 months for the patients with oropharyngeal cancer, 13.5 months for nasopharyngeal cancer and 17.7 for hypopharyngeal cancer. The most important factors that were associated with a poor prognosis were stage IV in oropharyngeal [Hazard ratio (HR) 3.68, 95% confidence interval (CI) 0.97-13.92] and hypopharyngeal cancer (HR 3.99, CI 1.51-10.67) and age over 65 years in nasopharyngeal cancer (HR 9.28, CI 1.79-47.99).     

Vascular endothelial growth factor C is required for sprouting of the first lymphatic vessels from embryonic veins

Lymphatic vessels are essential for immune surveillance, tissue fluid homeostasis and fat absorption. Defects in lymphatic vessel formation or function cause lymphedema. Here we show that the vascular endothelial growth factor C (VEGF-C) is required for the initial steps in lymphatic development. In Vegfc-/- mice, endothelial cells commit to the lymphatic lineage but do not sprout to form lymph vessels. Sprouting was rescued by VEGF-C and VEGF-D but not by VEGF, indicating VEGF receptor 3 specificity. The lack of lymphatic vessels resulted in prenatal death due to fluid accumulation in tissues, and Vegfc+/- mice developed cutaneous lymphatic hypoplasia and lymphedema. Our results indicate that VEGF-C is the paracrine factor essential for lymphangiogenesis, and show that both Vegfc alleles are required for normal lymphatic development.     

Incidences of selected lesions in control female Harlan Sprague-Dawley rats from two-year studies performed by the National Toxicology Program

The NTP has a long history of using Fischer rats and has compiled a large database of incidences of lesions seen in control animals. Such a database is lacking for Harlan Sprague-Dawley (SD) rats. The intention of this paper is to report spontaneous lesions observed in female vehicle control Harlan SD rats, and to compare the incidence in 2 strains of rats (Fischer and Harlan SD) used in NTP studies. Female Harlan SD rats served as the test animals for a special series of 2-year studies. Male rats were not used in these studies. Complete histopathology was performed on all animals, and the pathology results underwent comprehensive NTP pathology peer review. The most commonly observed neoplasms in these female control Harlan SD rats were mammary gland fibroadenoma (71%), tumors of the pars distalis of the pituitary (41%) and thyroid gland C-cell tumors (30%). Female Fischer rats had incidences of 44% for mammary gland fibroadenomas, 34% for tumors of the pars distalis, and 16% for thyroid gland C-cell tumors. Fischer rats had a 15% incidence of clitoral gland tumors, while the Harlan SD rats had an incidence of < 1%. In contrast to Fischer F344 rats, the Harlan SD rats had a high incidence of squamous metaplasia of the uterus (44.2%). Squamous metaplasia is not a lesion commonly observed in NTP control Fischer rats. The Harlan SD rats had a very low incidence of mononuclear cell leukemia (0.5%), compared with an incidence of 24% in female Fischer rats.     

Salience of Guilty Knowledge Test items affects accuracy in realistic mock crimes.

Guilty Knowledge Test measuring electrodermal reactions was carried out in order to investigate the quality of different questions and the validity of the test in a situation that resembled a true crime. Fifty participants were randomly assigned to commit one of two realistic mock crimes, and were later tested with GKTs concerning both the crime they had enacted and the one they had no knowledge of. Different scoring systems (SCRs and peak amplitudes as well as raw and standardised scores) were employed and compared when analyzing the results. Although there were some false positives, the test was able to differentiate between the groups of guilty and innocent participants. With the best scoring systems, the test was able to classify up to 84% of the innocent and up to 76% of the guilty correctly according to a logistic regression analysis. ROC areas reflecting these same results reached values above .80. Questions on matters that demanded the participants' attention and were easier to remember had better discriminative power. With nearly all scoring methods, there was a significant interaction between the salience of the relevant items and the guilt of the participants. Participants reacted more strongly to salient relevant items when they were guilty, while no different reactions were observed for the non-salient items between guilty and innocent participants. It is suggested that, although the Guilty Knowledge Test appears to be a valid measure of guilty knowledge even in crimes that are close to real crimes, the principles on which guilty knowledge test questions are constructed should be more clearly specified.     

The effect of phenytoin in vitro on normal human mononuclear cells and on human lymphoblastoid B cell lines of different Ig isotype specificities

The anticonvulsant drug phenytoin, in less than cytotoxic concentrations, caused significant reductions in Ig secretion by unstimulated or EBV-stimulated normal MNC, as measured by PFC or secretion of Ig into the culture medium. Isotype-specific LBL varied in their sensitivity, the secretion of IgA (1 line) and IgG (3 lines) being reduced by phenytoin near therapeutic concentrations, whereas that of IgM (1 line) was resistant. Six-day exposure of MNC to phenytoin caused no selective depletion of or enrichment for B cells, monocytes or T cell subsets. The results suggest that the reduction in serum Ig levels reported in phenytoin-treated epileptic patients is, at least in part, due to a direct effect of the drug on the B lymphocyte. However, among EBV-activated normal MNC, those secreting IgA were no more sensitive to the drug than those secreting IgG or IgM, and other factors may, therefore, operate to cause the preferential reduction in serum IgA in phenytoin-treated patients.     

Weighted expectation maximization reconstruction algorithms with application to gated megavoltage tomography

We propose and investigate weighted expectation maximization (EM) algorithms for image reconstruction in x-ray tomography. The development of the algorithms is motivated by the respiratory-gated megavoltage tomography problem, in which the acquired asymmetric cone-beam projections are limited in number and unevenly sampled over view angle. In these cases, images reconstructed by use of the conventional EM algorithm can contain ring- and streak-like artefacts that are attributable to a combination of data inconsistencies and truncation of the projection data. By use of computer-simulated and clinical gated fan-beam megavoltage projection data, we demonstrate that the proposed weighted EM algorithms effectively mitigate such image artefacts.     

Sleep-wake rhythm in an irregular shift system

Sleep in shift work has been studied extensively in regular shift systems but to a lesser degree in irregular shifts. Our main aim was to examine the sleep-wake rhythm in shift combinations ending with the night or the morning shift in two irregular shift systems. Three weeks' sleep/work shift diary data, collected from 126 randomly selected train drivers and 104 traffic controllers, were used in statistical analyses including a linear mixed model and a generalized linear model for repeated measurements. The results showed that the sleep-wake rhythm was significantly affected by the shift combinations. The main sleep period before the first night shift shortened by about 2 h when the morning shift immediately preceded the night shift as compared with the combination containing at least 36 h of free time before the night shift (reference combination). The main sleep period before the night shift was most curtailed between two night shifts, on average by 2.9 and 3.5 h among the drivers and the controllers, respectively, as compared with the reference combination. Afternoon napping increased when the morning or the day shift immediately preceded the night shift, the odds being 4.35-4.84 in comparison with the reference combination. The main sleep period before the morning shift became 0.5 h shorter when the evening shift preceded the morning shift in comparison with the sleep period after a free day. The risk for dozing off during the shift was associated only with the shift length, increasing by 17 and 35% for each working hour in the morning and the night shift, respectively. The results demonstrate advantageous and disadvantageous shift combinations in relation to sleep and make it possible to improve the ergonomy of irregular shift systems.