Sucralfate attenuates gastric mucosal lesions and increased vascular permeability induced by ischaemia and reperfusion in rats

Recent evidence suggests that oxygen-derived free radicals are involved in mediating gastric microvascular and parenchymal cell injuries induced by ischaemia and reperfusion. Therefore, the effect of the locally acting anti-ulcer drug, sucralfate, was studied on ischaemia and reperfusion (e.g. induced gastric lesions, intraluminal bleeding, changes in vascular permeability and non-protein sulfhydryl levels in the rat stomach). Allopurinol was used as a known standard antioxidant drug. Rats were subjected to 30 min of gastric ischaemia in the presence of 100 mmol/L hydrochloric acid and reperfusion periods of 15, 30 or 60 min duration. The gastric lesions were assessed microscopically under an inverted microscope. The vascular permeability was quantified by measuring the extravasated Evans blue in the stomach. There were significantly greater numbers of gastric lesions, intraluminal bleeding and leakage of Evans blue during all reperfusion periods as compared with those of ischaemia, with maximum effects occurring at 60 min following reperfusion. Pretreatment with sucralfate (31.25-250 mg/kg, p.o.) or allopurinol (12.5-50 mg/kg, i.p.) 30 min before the procedure, dose-dependently reduced the gastric lesions, intraluminal bleeding, and decreased the vascular permeability induced by ischaemia and reperfusion. Furthermore, sucralfate dose-dependently reverses the ischaemia and reperfusion-induced depletion of mucosal non-protein sulfhydryl levels and inhibited the superoxide radical production in both cell-free xanthine-xanthine oxidase and in the stimulated polymorphonuclear cellular systems. These results suggest that the protection produced by sucralfate against gastric injury may be due to its antioxidant effects.     

Kinetic analysis of papaya proteinase omega

Papaya proteinase omega (pp omega) has been purified from dried latex both by immunoaffinity and traditional methods. Kinetic analysis revealed that (1), the pp omega-catalysed hydrolysis of N-benzoyl-L-arginine p-nitroanilide (BApNA) has a lower specificity (kcat/Km) than the same reaction catalysed by papain; (2), the pp omega-catalysed hydrolysis of a tripeptide substrate having phenylalanine at the second position (S2-site) showed a more similar specificity to that catalysed by papain; (3), the significant difference between the two enzymes is that steady state kinetics with both L-BApNA and a tripeptide enables the identification in pp omega of other ionizations affecting binding. The active sites of papain and pp omega can therefore be distinguished by pH-dependence of kcat/Km.     

Study of a BGO calorimeter using electron and hadron beams from 1 to 50 GeV

A calorimeter of 25 bismuth germanate (BGO) crystals equipped with silicon photodiode readout has been tested at the CERN SPS in the energy range 1–50 GeV. The response for electrons has been shown to be linear in this energy range and the rms resolution obtained ( ) is approximately 1%, for E > 4 GeV. The electron/pion separation was found to be better than 1:500 in the energy range 1–20 GeV. Data on lateral and longitudinal shower development were compared with the results of a Monte Carlo simulation using the SLAC-EGS program and found to be in good agreement.     

Microscopical imaging of hydroxyapatite/mica composite and packed hydroxyapatite structure--an atomic force microscopy investigation

A focus on the importance of leisure in the development of student nurses has been neglected in the 1990s. This study considers 444 prospective nurses on conventional, diploma and degree courses in two areas of England. It examines their activities associated with socializing, their social support networks and their use of clubs, sports and hobbies before entering nursing. It is evident that students enter nurse training with a wide variety of leisure experiences. Changing recruitment patterns and the structure of nurse training has an effect on the leisure needs of prospective nurses which must be addressed.     

The nature of lexical knowledge

This paper considers the nature of lexical knowledge and its role in language and information processing. The lexicon is the central component of language and plays a pivotal role in current linguistic theory [3, 4] and, increasingly, in natural language processing systems [5-7]. The lexicon embodies information about the lexical items of the language and serves as the foundation for morphologic, syntactic, and semantic processing. The differences as well as commonalities among dictionaries, thesauri, and lexicons are discussed, and distinctions between words, lexical items, and terms are drawn. Next, the scope and content of the SPECIALIST lexicon are presented, followed by a discussion of certain writing conventions that can be troublesome for text processing applications. One approach to handling orthographic and other lexical variation is discussed in a section that reports on the design and implementation of the SPECIALIST lexical programs. The paper concludes with a discussion of controlled terminologies for the medical domain. Throughout the discussion, examples are drawn from the SPECIALIST lexicon and from the other UMLS knowledge sources [8, 9].     

Outcomes related to burn-related child abuse: a case series

Nationally, approximately 10% of child abuse cases involve burning, and up to 20% of pediatric burn admissions involve abuse or neglect. Historically, these cases have been more difficult to prosecute than nonburn cases for multiple reasons. Between 1995 and 1999, there were 285 pediatric (under 18) patients admitted to the Spectrum Health Regional Burn Center. Of these cases, 18 of the alleged perpetrators were legally investigated for suspicion of child abuse, and 7 received punitive sentences. We found that men tended to be prosecuted and convicted more often than women and that cases involving multiple instances of injury tended to be prosecuted more frequently. Similarly, we found that cases involving more severe injuries tended to be prosecuted more successfully. There are many psychological and social factors involved in handling burn abuse cases. However, by successful prosecution of these crimes, victims tend to fare better both socially and psychologically.     

Serologic and molecular detection of granulocytic ehrlichiosis in Rhode Island

A new indirect fluorescent-antibody (IFA) assay with antigen produced in vitro in the human promyelocytic leukemia cell line HL60 was used to identify the first recognized case of human granulocytic ehrlichiosis in Rhode Island. This IFA assay was used to detect granulocytic ehrlichiae in white-footed mice and in a dog inhabiting the area surrounding the patient's residence. Host-seeking Ixodes scapularis ticks found in the same habitat also were infected. I. scapularis ticks collected from other locations were fed on dogs and New Zealand White rabbits to assess the competency of these species as hosts of granulocytotropic Ehrlichia. Tick-induced infections of dogs were confirmed by serologic testing, tissue culture isolation, and PCR amplification, whereas several rabbits seroconverted but were PCR and culture negative. PCR amplification of the 16S rRNA gene and DNA sequencing of the PCR products or culture isolation was used to confirm granulocytic Ehrlichia infections in humans, dogs, white-footed mice, and ticks.     

Clinical applications of fundus reflection densitometry

Fundus reflection densitometry or retinal densitometry is a non-invasive technique to examine the visual photopigment kinetics in living eyes. The technique is based on the comparison of the reflected light from the fundus in a fully light adapted eye (when all visual photopigment has been bleached) with the reflected light following complete dark adaptation (when the retina contains its maximum amount of visual photopigment). The technique provides a measure of the density of visual photopigment, its time constant of regeneration, its distribution and spectral characteristics if measured at a series of wavelengths. Fundus reflection densitometry in the human eye was introduced 40 years ago. Presently, it is the only available technique from which direct and objective insight can be obtained into visual photopigment. This knowledge is particularly relevant in eyes where abnormalities of photoreceptor function are suspected. This paper summarizes the current knowledge of fundus reflection densitometry in the diseased and in the aging human retina, gathered over the last 30 years. Considerable improvements of the instrument for clinical purposes have been obtained, and are also discussed.