Familial transmission of a serious disease--producing group A streptococcus clone: case reports and review

Invasive group A streptococcus (GAS) infections are emerging diseases; however, person-to-person transmission of invasive GAS producing life-threatening infection has been observed rarely. We report a small intrafamilial cluster of life-threatening GAS infections. A previously healthy 47-year-old father developed necrotizing fasciitis of the neck. Two days later, his 16-year-old daughter developed streptococcal angina, pneumonia, and pleural empyema. Both patients had signs of streptococcal toxic shock syndrome. Pulsed field gel electrophoresis revealed that the M6 strains of GAS isolated from the father and daughter had identical patterns. Cases of person-to-person transmission of invasive GAS infection reported in the literature are also reviewed.     

Analysis of protein domain families in Caenorhabditis elegans

The Caenorhabditis elegans genome sequencing project has completed over half of this nematode's 100-Mb genome. Proteins predicted in the finished sequence have been compiled and released in the data-base Wormpep. Presented here is a comprehensive analysis of protein domain families in Wormpep 11, which comprises 7299 proteins. The relative abundance of common protein domain families was counted by comparing all Wormpep proteins to the Pfam collection of protein families, which is based on recognition by hidden Markov models. This analysis also identified a number of previously unannotated domains. To investigate new apparently nematode-specific protein families, Wormpep was clustered into domain families on the basis of sequence similarity using the Domainer program. The largest clusters that lacked clear homology to proteins outside Nematoda were analyzed in further detail, after which some could be assigned a putative function. We compared all proteins in Wormpep 11 to proteins in the human, Saccharomyces cerevisiae, and Haemophilus influenzae genomes. Among the results are the estimation that over two-thirds of the currently known human proteins are likely to have a homologue in the whole C. elegans genome and that a significant number of proteins are well conserved between C. elegans and H. influenzae, that are not found in S. cerevisiae.     

A simplified sequence for observing deoxymyoglobin signals in vivo: myoglobin excitation with dynamic unexcitation and saturation of water and fat (MEDUSA)

This paper describes a new, simplified pulse sequence for observing NMR signals from deoxymyoglobin in vivo. Paramagnetically shifted resonances from deoxymyoglobin can be exploited to noninvasively calculate intracellular oxygen tension in striated muscle. However, special sequences are required to observe these weak signals against the larger water and fat signals encountered in vivo. The pulse sequence described here, which is based on inversion recovery sequences, efficiently suppresses both water and fat resonances and can be implemented with short repetition rates. Moreover, it is perfectly suited for studies with surface coils, where RF inhomogeneities render other popular suppression sequences ineffective.     

Tricyclic antidepressant-induced lipidosis in human peripheral monocytes in vitro, as well as in a monocyte-derived cell line, as monitored by spectrofluorimetry and flow cytometry after staining with Nile red

Human mono- and lymphocytes from peripheral blood and the monoblastoid cell line U-937 were used in this in vitro study of drug-induced lipidosis. Mono- and lymphocytes were exposed for 4 days to three different tricyclic antidepressants (TCAs), imipramine (25 microM), clomipramine (10 microM) and citalopram (80 microM). The lipophilic fluorophore Nile red, which stains intracellular lipid structures selectively, was used as a lipid probe. Fluorescence microscopy, spectrofluorimetry and flow cytometry were used to detect cellular lipidosis, as verified by electron microscopy. Our results demonstrate that imipramine, clomipramine and citalopram induce lipidosis in monocytes and U-937 cells, but not in lymphocytes. An accurate quantitation of induced intracellular lipidosis can be achieved by spectrofluorimetric and flow cytometric analysis.     

Dry machinability of nickel-based weld-hardfacing layers for hot tooling

This paper deals with a study on the dry machinability of the nickel-based hardfacing layers used in the manufacturing of hot tooling. Several machining tests were carried out on 56NiCrMoV7 steel block with thickness of 60 mm (substrate). Five layers of Hastelloy C type with thickness varying between 2 and 3 mm were deposited on the substrate using flux cored-wire welding (pulsed semi-automatic MIG). In the accelerated machining tests (AMT), only the nature of the hardfacing layers were changed. The cutting speed V_c of 80 m/min, the axial depth of cut a_p of 0.12 mm, the radial depth of cut a_c of 12 mm and the feed rate f_z of 0.05 mm/tooth were considered in the AMT tests. It was found that the main limitation of this hardfacing in machining is associated with its highly heterogeneous metallurgical structure. This heterogeneity consists of a dendritic network (ductile nickel phase) separated by a fragile interdendritic dispersion (carbide phase and fine or coarse precipitate phases). This is expressed during cutting tests by the high hardness of the workpiece surface that involves premature wear of cutting tools. This deterioration is caused by the adhesion of the produced chips (dry sticking friction) leading to notches and very severe chipping of the cutting edge, following a crumbling of the tool material.     

The past, present, and future of the prevention of lung cancer

The article relates details of the history of research into the causal association of cigarette smoking and lung cancer on the basis of multidisciplinary studies that have explored the epidemiology, biology, chemistry, and biochemistry of tobacco carcinogenesis and research in behavioral sciences and health education that has sought to address one of our nation's foremost public health problems. Recalling past and present challenges and achievements in all of these areas, the author then outlines his vision for addressing this health problem in the future. This is laid out for various segments of the research community and for society as a whole, i.e., Cancer Centers and hospitals, epidemiologists, laboratory scientists, legislators, educators and behavioral scientists, and the media. It is proposed that for the current policy initiatives in tobacco-related cancer control to succeed, there needs to be a focus on preventing the initiation of tobacco use among children and adolescents. All segments of society can help to achieve this goal. In the nation's research planning, there needs to be a proper balance between basic and applied research, including research on and application of preventive principles, because cancer need not be an inevitable consequence of aging but is largely preventable.     

Focus group interviews: assessment of continuing education needs for the advanced practice nurse

This article reports the use of focus group interviews to promote the development of continuing education programs that meet the needs of advanced practice nurses (APNs). The three major needs identified were: a) enhancement of clinical practice skills and knowledge in specialty areas, b) education about future changes in the APN role, and c) education in management strategies for the changing health care delivery system. A summary of the investigation and implications for continuing nursing education departments are also presented.