28 research outputs found
Plasticity of neuropeptidergic neoplasm cells in the primary and metastatic Merkel cell carcinoma
Merkel cell carcinoma (MCC) is a rare and highly aggressive cutaneous carcinoma with characteristics of neuroendocrine tumor. We performed immunohistochemical analysis to demonstrate the presence of various neuropeptides within cells of MCC resected from a 75-year old woman. The cells of primary tumor of cheek were compared with the cells of regional right submandibular metastatic tumor which was found eight months later. A double- staining IHC for the pan-neuronal marker, PGP 9.5, and selected neuropeptides in the tissue material obtained from both locations was performed. Single multipolar cells in the main mass of primary tumor stained positively for PGP 9.5 and such neuropeptides as GAL, VIP, PACAP, NPY and CGRP. Moreover, we demonstrated for the first time the presence of neuropeptides in metastatic MCC cells. In the metastatic tumor, cells showing the co-localization of PGP-9.5 and neuropeptides were more numerous, mostly of oval shape, and significantly smaller than in the primary tumor. Thus, the progression of MCC may be associated with the acquisition by its cells of new morphological and biological features
Exotic phase transitions in RERhSn compounds
Crystal and magnetic properties of three equiatomic ternary RERhSn compounds (where RE = Ce, Nd, Gd) have been studied by means of X-ray diffraction, ac, and dc magnetic susceptibility measurements, as well as using Mössbauer spectroscopy with 119Sn and 155Gd resonances. CeRhSn does not order magnetically down to 2 K while NdRhSn undergoes ferromagnetic transition at TC = 10.3 K and GdRhSn orders antiferromagnetically below TN = 16 K. Our CeRhSn and NdRhSn samples become superconductive below 6.5 K and 6.9 K, respectively
Ultrastructure of the ventromedial hypothalamic nucleus in fasted and refed young and old rats
Many hypothalamic nuclei are involved in the regulation of food intake and
energy homeostasis. An ultrastructural investigation of the hypothalamic ventromedial nucleus (VMN), a hypothetical "satiety centre" was performed to explore the morphological basis of altered feeding behaviour of old rats in an experimental model of fasting/refeeding. Young (5 months old, n = 12) and old (24 months old, n = 12) male Wistar rats were fasted for 48 hours, then refed for 24 hours and sampled thereafter. Brain tissue was fixed by perfusion, histological
and ultrathin sections were obtained by routine methods. Although food
intake was similar in control young and old rats, during refeeding old animals consumed less chow than young ones. The EM analysis of VMN neurones of old control rats revealed, besides typical age-related residual bodies, deep indentations of the nuclear envelope and the presence of long, undulating rough endoplasmic
reticulum cisternae in the cell periphery. In both young and old rats
fasting for 48 hours led to the expansion of Golgi complexes and increased folds of the nuclear envelope, which is suggestive of enhanced cellular activity of the
VMN neurones. These fasting-induced alterations were sustained in the VMN
neurones of refed rats in both age groups. The results showed that the VMN
neurones of old control rats differ at the ultrastructural level from young ones. However, starvation and subsequent refeeding cause similar alterations in the hypothalamic neurones of "satiety centre" of both young and old rats
The effect of fasting and refeeding on the ultrastructure of the hypothalamic paraventricular nucleus in young and old rats
In order to explore the morphological basis of the altered feeding behaviour of
old rats, an ultrastructural investigation of the magnocellular neurons of the
hypothalamic paraventricular nucleus (PVN) was performed. Young and old male
Wistar rats, 5 and 24 months old, respectively, and with each age group comprising
12 animals, were divided into 3 groups. The rats in Group I were used as
controls (normally fed), the rats of Group II were fasted for 48 hours and in
Group III the rats were fasted for 48 hours and then refed for 24 hours. The
brains were fixed by perfusion and histological and ultrathin sections were obtained
by routine methods. Common features of the magnocellular PVN neurons
of young and old rats were abundant Golgi complexes and short fragments
of RER localised at the cell periphery. In contrast to young rats, the PVN neurons
of old animals showed deep indentations of the nuclear envelope and agerelated
residual bodies. In both age groups fasting for 48 hours led to the expansion
of the Golgi complexes and dilatation of RER cisternae. In contrast to
those in fed rats, RER cisternae in the neurons of old fasted animals were situated
between the nuclear envelope and the Golgi zone. Prolonged RER cisternae
were distributed in the peripheral cytoplasm of refed old rats. Our observations
suggest that at the ultrastructural level the process of ageing does not change
the responsiveness of magnocellular PVN neurons to fasting-refeeding
Risk factors for cardiac arrhythmias in children with congenital heart disease after surgical intervention in the early postoperative period
ObjectiveEarly postoperative arrhythmias are a recognized complication of pediatric cardiac surgery.MethodsDiagnosis and treatment of early postoperative arrhythmias were prospectively analyzed in 402 consecutive patients aged 1 day to 18 years (mean 29.5 months) who underwent operation between January and December 2005 at our institute. All children were admitted to the intensive care unit, and continuous electrocardiogram monitoring was performed. Risk factors, such as age, weight, Aristotle Basic Score, cardiopulmonary bypass time, aortic crossclamp time, and use of deep hypothermia and circulatory arrest, were compared. Statistical analysis using the Student t test, Mann–Whitney U test, or Fisher exact test was performed. Multivariate stepwise logistic regression was used to assess the risk factors of postoperative arrhythmias.ResultsArrhythmias occurred in 57 of 402 patients (14.2%). The most common types of arrhythmia were junctional ectopic tachycardia (21), supraventricular tachycardia (15), and arteriovenous block (6). Risk factors for arrhythmias, such as lower age (P = .0041⁎), lower body weight (P = .000001⁎), higher Aristotle Basic Score (P = .000001⁎), longer cardiopulmonary bypass time (P = .000001⁎), aortic crossclamp time (P = .000001⁎), and use of deep hypothermia and circulatory arrest (P = .0188⁎), were identified in a univariate analysis. In the multivariate stepwise logistic regression, only higher Aristotle Basic Score was statistically significant (P = .000003⁎) compared with weight (P = .62) and age (P = .40); in the cardiopulmonary bypass group, only longer aortic crossclamp time was statistically significant (P = .007⁎).ConclusionLower age, lower body weight, higher Aristotle Basic Score, longer cardiopulmonary bypass time, aortic crossclamp time, and use of deep hypothermia and circulatory arrest are the risk factors for postoperative arrhythmias. Junctional ectopic tachycardia and supraventricular tachycardia were the most common postoperative arrhythmias
Object detection in security applications using dominant edge directions
This paper presents a novel approach to object detection in images. We build on the existing work on detecting knives in images, which has previously attempted to solve the problem by using the well-established histogram of oriented gradients (HOG) features. We introduce a new feature set that allows for rapid initial object location in images, and can then be followed by the use of an object specific detector. This approach allows for speeding up the overall detection process, which has been demonstrated on the example of knives, and is in the position of bringing many object detectors closer to real-time execution speeds
Visual detection of knives in security applications using Active Appearance Models
In this paper, a novel application of Active Appearance Models to detecting knives in images is presented. In contrast to its popular applications in face segmentation and medical image analysis, we not only use this computer vision algorithm to locate an object that is known to exist in an analysed image, but–using an interest point typical of knives–also try to identify whether or not a knife exists in the image in question. We propose an entire detection scheme and examine its performance on a sample test set. The work presented in this paper aims to create a robust visual knife-detector to be used in security applications
The effects of galactosamine on UTP levels in the livers of young, adult and old rats.
Galactosamine (GalN), a well-known hepatotoxin that depletes the cellular pool of uracil nucleotides, was previously shown to have greater impact on the inhibition of protein synthesis in hepatocytes of old rats as compared with young animals (Kmieć 1994, Ann. N.Y. Ac. Sci. 717, 216-225). In the present study we compared the effects of GalN on the nucleotide content (measured by ion-exchange HPLC) in the livers of young (4 months), adult (12 months), and old (24-26 months old) rats two hours after its intraperitoneal administration. UTP content of the livers of old control rats was significantly lower (by 28%) than that of young animals. GalN administration decreased the UTP content in the livers of young, adult and old rats by, respectively, 55%, 65% and 89%, and increased the content of UDP-sugars by 189%, 175% and 305%. The hepatic content of ATP, ADP, AMP, NAD, GTP except CTP did not differ significantly among the age groups of rats studied, and was not changed by GalN treatment. The content of CTP was significantly higher in old rats (P < 0.03) upon GalN treatment. The lower hepatic content of UTP may partially explain the increased sensitivity of hepatocytes and livers of old rats to the action of galactosamine, and possibly to other hepatotoxic compounds that decrease transcription in the liver
Electronic and magnetic properties of ternary stannides RERhSn (RE=light rare-earth metals)
The results of magnetic studies and Mössbauer investigations made with ^{119}Sn and ^{155}Gd sources are reported for the series of RERhSn (RE=La, Ce, Pr, Nd, and Gd) compounds crystallizing in the hexagonal ZrNiAl-type structure. The role of CEF effects in the establishing of magnetic moments orientations observed in these compounds and their influence on the observed magnitudes of magnetic moments is discussed