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At least 1,297 records · Page 72Linked to original sources
PubMed2005

System weaknesses as contributing causes of accidents in health care.

OBJECTIVE: Accidents in health care, resulting in injury or death to the patient, are a matter of considerable concern. The aim of this study is to examine whether system weaknesses can contribute to these accidents, and if so, how. DESIGN: Eight consecutive accidents reported to the Health Authority in Sweden were analysed using MTO (Man-Technique-Organization) analysis. SETTING: Emergency care hospitals in Sweden. RESULTS: All cases that involved the system supported the assumption that system weaknesses are a contributing factor to accidents. In this study two types of latent failure could be identified: process control latent failures and interactional latent failures. The time span from activation of process control latent failures to operator error was very short, and the study demonstrates the simple relationship between situational factors and operator errors. Interactional latent failures exert system influence in a more indistinct manner. Latent failures, as seen in this study, act not only by creating opportunities for operator errors but also by hindering error detection in the time window available. Safety barriers, which might have prevented the accidents, could be proposed in seven out of eight cases. CONCLUSION: System weaknesses seem to play an important role in accident evolution. Consequently, certain measures can be suggested in order to improve patient safety: (i) sufficient resources should be allocated for research and development at both medical schools and hospitals in order to establish competence and procedures for systematic analyses of processes; and (ii) authorities handling accident cases should have adequate competence in system analysis.

Accident Prevention↗
PubMed2002

The evolutionary history of kinetoplastids and their kinetoplasts.

Despite extensive phylogenetic analysis of small subunit ribosomal RNA (SSUrRNA) genes, the deep-level relationships among kinetoplastids remain poorly understood, limiting our grasp of their evolutionary history, especially the origins of their bizarre mitochondrial genome organizations. In this study we examine the SSUrRNA data in the light of a new marker--cytoplasmic heat shock protein 90 (hsp90) sequences. Our phylogenetic analyses divide kinetoplastids into four main clades. Clades 1-3 include the various bodonid kinetoplastids. Trypanosomatids comprise the fourth clade. SSUrRNA analyses give vastly different and poorly supported positions for the root of the kinetoplastid tree, depending on the out-group and analysis method. This is probably due to the extraordinary length of the branch between kinetoplastids and any out-group. In contrast, almost all hsp90 analyses place the root between clade 1 (including Dimastigella, Rhynchomonas, several Bodo spp., and probably Rhynchobodo) and all other kinetoplastids. Maximum likelihood and maximum likelihood distance analyses of hsp90 protein and second codon-position nucleotides place trypanosomatids adjacent to Bodo saltans and Bodo cf. uncinatus (clade 3), as (weakly) do SSUrRNA analyses. Hsp90 first codon- plus second codon-position nucleotide analyses return a slightly different topology. We show that this may be an artifact caused, in part, by the different evolutionary behavior of first- and second-codon positions. This study provides the most robust evidence to date that trypanosomatids are descended from within bodonids and that B. saltans is a close relative of trypanosomatids. A total reevaluation of the high-level systematics within kinetoplastids is needed. We confirm that the interlocking network organization of kinetoplast DNA seen in trypanosomatids is a derived condition within kinetoplastids but suggest that open-conformation minicircles may have arisen early in kinetoplastid evolution. Further understanding of the evolution of kinetoplast structure and RNA editing is hampered by a paucity of data from basal (i.e., clade 1) bodonids.

Animals↗
PubMed2003

The 'novel' 'uncoupling' proteins UCP2 and UCP3: what do they really do? Pros and cons for suggested functions.

The scientifically novel, but evolutionarily ancient, so-called uncoupling proteins 2 and 3 (UCP2, UCP3) are structurally similar to the archetypical uncoupling protein UCP1. A series of suggestions have been forwarded for their physiological function. We discuss systematically here the pros and cons for these suggestions. We conclude that the novel UCPs do not seem to be physiologically relevant uncoupling proteins; the uncoupling property was apparently a late introduction into the subfamily through the evolution of UCP1. Physiological functions ascribed to UCP2 and UCP3 based on their purported uncoupling property may have to be revised (i.e. any type of thermogenesis, including protection against obesity, protection against the formation of reactive oxygen species and thermogenic involvement in the fever response). The presence of a mixed genetic background in most published studies of UCP2 or UCP3 gene-ablated mice also means that data concerning marked differences in diabetes propensity, infection sensitivity and production of reactive oxygen species may require confirmation in backcrossed mice. The increased expression of UCP2 and UCP3 under conditions of increased fatty acid metabolism implies an as yet undefined role in lipid metabolism. Thus, the novel UCPs should probably be considered as mitochondrial carriers, and the challenge now is to identify the transported molecule.

Animals↗
PubMed1985

A system approach to new service development for hospitals.

A systematic approach to evaluating, planning and implementing new consumer services is necessary to ensure a successful program. Presented here are the three phases of the new service development process for hospitals--assessment, development, and execution--and the evolution and interaction among the health care delivery system, service, and market dimensions. Before, during, and after development, the need for hospital communications and effective marketing is also stressed.

Health Services Needs and Demand↗
PubMed2001

[Neuroretinitis in an HIV-infected patient].

CASE REPORT: We present a 35 year-old man, suffering from HIV infection with a left neuroretinitis and bilateral multifocal inner retinitis. A systematic approach supported the presumed diagnosis of cat-scratch disease. The patient was treated with oral azytromicine following a full-clinical recovery. DISCUSSION: We discuss the differential diagnosis of this clinical entity, treatment and clinical evolution.

Adult↗
PubMed1975

[Thermogenesis of breast cancers. V. The effects of 60Co radiotherapy and the correlations with expectations of a cure].

The action of ionizing radiation on the metabolic heat production by cancers has been investigated on a group of 24 small breast carcinomas (T1 and T2), all treated exclusively by radiotherapy under equivalent conditions (60Co) and then followed up regularly (mean recall period of five years). Following techniques have been used: intratumoral thermometry and fluvography for computing the specific heat power of the tumour, infrared thermography for analysing the skin thermal pattern quantitatively. Comparison between clinical, radiographical and thermal findings has more especially shown; a) the constant agreement between the final loco-regional results of radiotherapy and the evolution of both the heat production by the tumour and the related hyperthermia on the skin; b) the early appearance of the thermal signs of either a regression or a recurrence of the tumour, compared with the corresponding morphological signs. The fundamental and practical consequences can be summarized as follows: 1 degree distinction between radiosensitive and radioresistant carcinomas accroding as the specific heat power of the tumour is reduced or not after irradiation; 2 degrees definition of three types of thermal evolution by normalization, regression followed by re-increase, and continuance of both tumour heat production and malignant skin hyperthemia, and corresponding to the clinical concepts of sterilization, recurrence and nonsterilization respectively; 3 degrees justification of the systematic use of thermal methods for post-irradiation follow-up, especially to detect a local recurrence earlier and to specify the nature of a doubtful remaining opacity; 4 degrees description of objective thermal criteria allowing to decide a repairing mastectomy within shorter delays.

Adult↗
PubMedDate not supplied

[Reflections on the timeliness and utility of an ambulatory glaucoma center as part of the Colţea Ophthalmologic Clinic and the Bucharest Municipal Hospital].

The paper presents several remarks on opportunity and usefulness of the centre for outpatient follow up of glaucoma within the "Colţea" Ophthalmology Clinic and of the Bucharest Municipal Hospital. The unconfirmed, suspected patients were not considered glaucomatous. The exam of the eye has to be complete, to include the systematic investigation of the ocular tension, and of the visual field, by evidencing scotoma in Bjerrum's area photometric disharmonies and chromatic alterations. A special attention must be paid to the low pressure glaucoma, as a peculiar evolution form of glaucoma with open angle.

Ambulatory Care Facilities↗
PubMed1989

Identification of a locality in snake venom alpha-neurotoxins with a significant compositional similarity to marine snail alpha-conotoxins: implications for evolution and structure/activity.

alpha-neurotoxins from elapid snake venoms and alpha-conotoxins from marine snails bind specifically and with high affinity to nicotinic cholinoceptors. Although both types of toxin are polypeptides, there is more than a fourfold difference in size between the two and no clear sequence homology is evident. A systematic computer search of the three-dimensional structure of erabutoxin b (an alpha-neurotoxin from the false sea snake Laticauda semifasciata) was performed to identify the locality that most closely matched the amino acid compositions of the smaller alpha-conotoxins (from the marine snails Conus magus and Conus geographus). The area of greatest similarity centered on residue position 25 of erabutoxin b, a locale that is conserved throughout the snake alpha-neurotoxins and their homologues. Six proteins unrelated to erabutoxin b were compared to the alpha-conotoxins to show that the extent of the erabutoxin b/alpha-conotoxin match was too high to be coincidental. Homologues of erabutoxin b, namely alpha-cobratoxin from Naja naja siamensis and cytotoxin VII4 from Naja mossambica mossambica, were also analyzed. The extent of the matching with the alpha-conotoxins decreased in the series erabutoxin b greater than alpha-cobratoxin greater than cytotoxin VII4, and this also relates the order of similarity to the pharmacological properties of the alpha-conotoxins. The alpha-conotoxin-like area of the snake alpha-neurotoxins is peripheral to the site previously considered important for binding to the cholinoceptor, even though it seems to represent the focus of evolutionary convergence between the two types of neurotoxin. The area of resemblance does, however, have strong associations with the conformational behavior of the snake toxins. Hence, the outcome of this study has important consequences for the current ideas on snake alpha-neurotoxin structure/activity relationships and the evolutionary origins of neurotoxicity.

Amino Acid Sequence↗
PubMed2001

[Helicobacter pylori eradication. Therapeutic evolution, value of complementary studies].

INDICATIONS: Eradication of Helicobacter pylori is needed for patients with a gastroduodenal ulcer associated with H. pylori gastritis. Eradication modifies the natural history of the disease and greatly reduces the risk of recurrence. Eradication is also indicated for patients with MALT lymphoma with a low degree of malignancy. Systematic eradication of H. pylori would not be necessary for patients with dyspepsia associated with H. pylori gastritis since a beneficial effect is achieved in only 5% of the treated patients. Systematic eradication in order to reduce the incidence of gastric adenocarcinoma is not recommended. DIAGNOSIS: Direct tests (urease, pathology) provide the diagnosis of H. pylori gastritis. Indirect tests (13C-labeled urea respiratory test) can be most useful to determine the efficacy of eradication treatments. THERAPY: A tri-therapy regimen given for 7 days combining a double-dosed proton pump inhibitor, amoxicillin (2 g/d), and clarithromycin (0.5 g b.i.d) is used to eradicate H. pylori. With this regimen, the mean rate of eradication achieved in France is 67%. The principal causes of failure are poor compliance and bacterial resistance to clarithromycin. Metronidazole (1 g/d) can be used for patients allergic to penicillin. A second cycle can be prescribed in case of failure, substituting metronidazole for clarithromycin. FOLLOW-UP: Eradication treatment is prescribed for patients with an ulcer after confirmation of infection by one or two direct tests. Treatment efficacy can be assessed by the respiratory test for patients with a duodenal ulcer but is not systematically needed. Biopsy of a gastric ulcer can also provide an assessment of treatment efficacy. For patients with a non-complicated duodenal ulcer, antisecretion treatment is not required in addition to eradication treatment.

Adenocarcinoma↗
PubMed1997

Secondary amyloidosis in ankylosing spondylitis. A systematic survey of 137 patients using abdominal fat aspiration.

OBJECTIVE: To assess the frequency and clinical significance of amyloid deposits in abdominal fat in patients with ankylosing spondylitis (AS). METHODS: Abdominal subcutaneous fat aspiration (ASFA) by fine needle was performed in 137 unselected patients with AS of more than 5 years of disease evolution. A followup study was done of patients with amyloidosis in the abdominal fat (ASFA positive test) to evaluate the development of clinical amyloidosis. RESULTS: In 10 (9M/1F) patients with AS, the ASFA revealed amyloid deposits (prevalence of 7%). Patients with AS and an ASFA+ test were older and had more active and severe disease than those without AS. Only 2 ASFA positive test patients had clinical amyloidosis at the time of the test. After a followup period of 2-10 yrs (mean 5.4 +/- 3.2 yrs), 3 more patients developed symptomatology due to amyloidosis. All 5 patients with clinical amyloidosis showed nephropathy, and proteinuria was found in each. The remaining patients did not develop clinical amyloidosis during followup. CONCLUSION: Amyloid deposits in abdominal fat are not a rare finding in AS. A significant proportion of these patients do not develop clinical amyloidosis after a followup of several years. Thus, an ASFA + test in patients with AS is not always associated with a poor prognosis at least in the short term, although longer followup is required.

Adipose Tissue↗
PubMed2005

Neoadjuvant taxanes in the treatment of non-metastatic breast cancer: a systematic review.

In recent years the role of neoadjuvant (primary, preoperative) chemotherapy has undergone rapid progress. Initially, neoadjuvant chemotherapy use was limited to those patients with inoperable locally advanced breast cancer in an attempt to try to down-size the tumour to make effective surgery possible. The advent of more effective chemotherapy regimens has led to an increased use of neoadjuvant therapy to shrink potentially operable tumours to allow for breast conservation when a mastectomy would have been required previously. While neoadjuvant treatment for operable tumours has indeed allowed increased rates of breast conserving surgery, it has not yet demonstrated any survival benefit over standard postoperative anthracycline-based chemotherapy. Echoing the evolution of taxane based chemotherapy from the metastatic setting through to the adjuvant situation, there has been increased interest in the role of taxanes in neoadjuvant regimens. The use of taxane-based therapies in this setting has so far shown improvements over more standard regimens in terms of clinical response rates, breast conservation, pathologic response rates, disease free survival, and overall survival. The aim of this review is to systematically summarize and interpret the results of published randomized controlled trials of neoadjuvant taxane chemotherapy for women with non-metastatic breast cancer.

Breast Neoplasms↗
PubMed2026

Identification and characterization of the HSP gene family in the Chinese giant salamander: Expression patterns under combined environmental stress.

BACKGROUND: The Chinese giant salamander (Andrias davidianus) is a critically endangered living fossil species that is highly sensitive to changes in water temperature. However, systematic studies on the heat shock protein (HSP) gene family and its response mechanisms to environmental stress in this species remain limited. This study utilized transcriptome data from captive-bred salamanders exposed to combined temperature and pathogen stress. Bioinformatics tools were employed to identify the HSP gene family of A. davidianus (AndHSP) and to analyze their evolution, structure, and function, thereby revealing their regulatory mechanisms in response to environmental stress. RESULTS: A total of 72 AndHSPs were identified and classified into five subfamilies. Phylogenetic analysis revealed that each subfamily is evolutionarily conserved and functionally related. Gene expression analysis demonstrated that pathogen infection induced the expression of AndHSPs, and elevated temperature significantly intensified this response. Nine key differentially expressed genes were identified, predominantly from the AndHSP70 subfamily, with AndHSP70-18 exhibiting rapid heat-induced expression. Tissue-specific analysis showed high expression of AndHSP60 in the spleen. A qPCR validation confirmed the reliability of the transcriptome expression results. CONCLUSIONS: This study presents the first systematic identification of the AndHSP gene family and elucidates its cooperative stress response mechanisms under combined temperature and pathogen stress. These findings provide a molecular basis for understanding the species' environmental adaptation and have important implications for its conservation and artificial breeding.

Animals↗
PubMedDate not supplied

Formation of prebiochemical compounds in models of the primitive earth's atmosphere. I: CH4 NH3 and CH4 N2 atmospheres.

In order to understand the formation of organic compounds in the primitive atmosphere, the first steps of evolution in models of the primitive atmosphere were investigated. Mixtures containing C-H-N elements were subjected to a low pressure silent electric discharge for several seconds, and the resulting effluents were analysed mainly by gas chromatography, infrared spectrometry and chemical analysis. The formation of hydrocarbon (i.e. ethylene, acetylene, methylacetylene) and of nitrogen containing compounds (i.e. hydrogen cyanide, cyanogen, saturated nitriles, acylonitrile, cyanoacetylene) is reported. The influence of the initial mixture composition on the amount of compounds formed was systematically studied. The nature of the nitrogen source (N2 or NH3) in the primitive atmosphere has a great influence on the amount and on the very nature of the synthesized products. It is shown that important precursors such as cyanogen and cyanoacetylene are formed only in very rich N2 mediums. These results show the important role played by the nature of the primitive atmosphere in the determination of the chemical evolution pathways.

Ammonia↗
PubMed2005

Intraspecific and interspecific genetic and phylogenetic relationships in the genus Populus based on AFLP markers.

Although Populus has become the model genus for molecular genetics and genomics research on forest trees, genetic and phylogenetic relationships within this genus have not yet been comprehensively studied at the molecular level. By using 151 AFLP (AFLP is a registered trademark of Keygene) markers, 178 accessions belonging to 25 poplar species and three interspecific hybrids were analyzed, using three accessions belonging to two willow species as outgroups. The genetic and phylogenetic relationships were generally consistent with the known taxonomy, although notable exceptions were observed. A dendrogram as well as a single most parsimonious tree, ordered the Populus sections from the oldest Leuce to the latest Aigeiros, a pattern consistent with their known evolutionary relationships. A close relationship between Populus deltoides of the Aigeiros section and species of the Tacamahaca section was observed and, with the exception of Populus wilsonii, between the species of the Leucoides, Tacamahaca, and Aigeiros sections. Populus nigra was clearly separated from its consectional P. deltoides, and should be classified separately from P. deltoides. The AFLP profiles pointed out to the lack of divergence between some species and revealed that some accessions corresponded with interspecific hybrids. This molecular study provides useful information about genetic relationships among several Populus species and, together with morphological descriptions and crossability, it may help review and update systematic classification within the Populus genus.

Cluster Analysis↗
PubMed1992

The role of western Asia in modern human origins.

Western Asia provides the best collection of human skeletal remains relevant to the two basic models for the emergence of modern humans, namely the 'rapid replacement' and the 'regional continuity' models. Regardless of the taxonomies of particular hominids, their chronology is of crucial importance. Thermoluminescence (TL) and electron spin resonance (ESR) dates demonstrate that the Acheulo-Yabrudian and Mousterian entities and their associated fossils (Zuttiyeh, Tabun, Skhul, Qafzeh, Kebara, Shanidar, Amud) span the late Middle and Upper Pleistocene period. These new dates initiated major chronological revisions and renewed discussion of the cultural-archaeological implications. One of the most important conclusions is that the Middle to Upper Palaeolithic transition (or Revolution) 45-40 ka ago has nothing to do with the appearance of anatomically early modern humans in western Asia, which occurred some 100 ka ago or more. The Levant, the coastal region of the eastern Mediterranean, was both a corridor for movement of humans and animals as well as a refugium during climatically harsh periods. The mixture of morphological characteristics among the available Middle Palaeolithic human fossils is interpreted as reflecting the presence of immigrant and local populations. Archaeologically observable behavioural changes are taken as hints to the pre-adaptations of the Middle to Upper Palaeolithic revolution. The archaeological record of western Asia can contribute significantly to explaining the Middle to Upper Palaeolithic revolution. This region was the core area where the 'Neolithic Revolution' took place. The shift to systematic cultivation and the domestication of animals occurred within a short time.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Primary fetal hydrothorax: A literature review and proposed antenatal clinical strategy.

OBJECTIVE: To investigate the prognostic factors for primitive fetal hydrothorax (PFHT) and propose a clinical strategy based on systematic literature review. METHODS: We reviewed 64 articles describing 204 cases of PFHT. For each case we focused on 11 criteria. We investigated prognostic factors in the 89 cases where no in utero treatment was undertaken. We also studied the impact of different in utero treatments on the evolution of PFHT. RESULTS: We have found 4 factors correlated with the course of PFHT: the presence of hydrops, gestational age at time of birth, the unilateral or bilateral nature of the effusion, and the occurrence of spontaneous resolution. With multivariate analysis, only hydrops remained determinant as a prognostic factor. CONCLUSIONS: Studies such as ours, reviewing case reports or series, are subject to the biases of literature underreporting of therapeutic failures or nonintervention. However (with the best available data) we propose a clinical approach to PFHT discovered in utero.

Female↗