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PubMed2000

A technology transfer model for effective HIV/AIDS interventions: science and practice.

The widespread use of effective, science-based interventions to motivate and sustain behavior change provides an important approach to reducing the spread of HIV. The process of disseminating information about effective interventions and building capacity for implementing them in field settings must be improved, however. Starting with a review of diffusion of innovations and technology transfer literature, we offer a technology transfer model for HIV interventions. We identify participants and activities directed toward the use of effective interventions by prevention services providers (e.g., health departments and community-based organizations) in each phase of technology transfer: preimplementation, implementation, and maintenance and evolution. Preimplementation activities focus on selecting an intervention and preparing for implementation. Implementation activities include initial implementation and process evaluation. Maintenance and evolution are ongoing with continued support for and evaluation of the intervention. This article takes the perspective of providers. Other perspectives are presented elsewhere in this issue.

HIV Infections↗

PubMed2000

[Monitoring of ischemic changes of the QRS complex with a new system of computerized electrocardiography].

BACKGROUND: Evoked ischemia induces morphological modifications in QRS complex that can be detected by a new electrocardiographic computerized system that we have developed (ventricular ischemic site analysis-VISA). The aim of this study was to evaluate, by continuous recording, the ischemia evolution during stress or pharmacological test and to correlate the modifications of QRS with the shift of the ST-T segment. METHODS: According to our method, the vectorial differences between rest QRS and stress QRS are recorded as deformations of the QR and/or RS segments. Sixty patients were studied: 44 had inducible ischemia during single photon emission computed tomography 99mTc-sestamibi test; 33 of these underwent ergometric test and 11 pharmacological test. RESULTS: The VISA test was positive in 91% of patients against the 61% with standard ECG. Ischemic deformations of the QRS appeared at 62.1% of stress duration, while the ST-T shift appeared at 81.4% of the test. During pharmacological stress the ST-T segment did not change. CONCLUSIONS: Our method is more sensitive than standard ECG in identifying inducible ischemia. Ischemic deformations of the QRS complex occur earlier than the repolarization modifications and they may be present also in their absence. The higher sensitivity of the VISA test depends on the fact that QRS ischemic modifications are caused both by the lesion current and a conduction delay in the ischemic zone.

Diagnosis, Computer-Assisted↗

PubMed2001

European School of Oncology: 20 years of cancer education and a contribution to European Guidelines of Oncology.

Since its creation in 1982, the European School of Oncology (ESO) not only looks back on two successful decades of cancer education and active promotion of knowledge and provision of oncology training in almost all parts of the world, but also the establishment of the State-of-the-Art (START) European oncology guidelines, a free, Internet-based, and readily accessible program of evidence-based medicine. In addition, ESO has been at the forefront of various activities which have led to the evolution of a common Continuing Medical Education system in Europe. A special framework to support the training of health care providers in underdeveloped countries was also launched by ESO. On the occasion of its 20th anniversary, ESO reflects on the past, defines the status quo and presents its future prospects.

Decision Support Techniques↗

PubMed2001

Chronic diseases--facing a public health challenge.

Middle income countries like those in the Caribbean can feel proud of their achievements in health care. There has been a dramatic fall-off in infant mortality and crude mortality rates along with significant improvements in life expectancy at birth. However, these countries now find themselves grappling with the burden of chronic non-communicable diseases such as heart disease, stroke, hypertension, diabetes mellitus and cancer. There are good data to support the view that some of these diseases, in particular diabetes mellitus, have assumed epidemic proportions and there is concern that this fact may have been missed by many because of the surreptitious onset, as is the nature of the chronic diseases. The impact of this epidemic may have suffered because of the higher profile of more topical issues like HIV/AIDS even though the former makes a larger contribution to morbidity and mortality statistics. It is now obvious that despite the impact of other factors, lifestyle changes are the major contributors to the epidemic. In populations of similar genetic stock, living in significantly different socio-economic circumstances, the impact of increased dietary salt, increasing obesity and decreased physical activity on the prevalence of hypertension, diabetes mellitus and lipid disorders is unequivocal. Data from the developed world, which has already been through this epidemic of chronic diseases, have shown that increasing technological advances in medical care is an inefficient way to respond to the situation. A multi-sectoral approach is required to tackle this epidemic, including the provision of incentives for healthy eating and widespread opportunities for increased exercise and other physical activities. Continued research into the evolution of the epidemic, including reliable estimates via surveillance methods is a necessary component of our response. The problems and the solutions are not only the responsibilities of the health officials but must involve education, agriculture and other sectors of the economy.

Caribbean Region↗

PubMed2002

The New Zealand health reforms of the 1990s in context.

The New Zealand health sector reforms of the 1990s have to be seen in the context of the long term development of the New Zealand health system. The evolutionary change between 1938 and 1990 was abruptly replaced by the revolutionary policy of commercialization from 1991 to 1993. This proved unsatisfactory, with the promised benefits such as significant productivity increases not occurring. In some ways the system functioned even more imperfectly, although this was in part due to the funding cutbacks which took place at the same time. The policy shifts from the mid 1990s have largely taken the New Zealand health system back to where it would have been, had the evolution up to 1990 continued. There remains unfinished business, the largest of which is that the tensions between the managers and the health professionals have not been resolved. The New Zealand experience provides strong evidence that comprehensive commercialization--business practices within, market relations between institutions--will not make a significant contribution to the design of effective health systems.

Health Care Reform↗

PubMed2003

Management of scoliosis.

The etiology and nature of truncal deformity in idiopathic scoliosis remains unclear. Only 2 methods are effective to halt or correct the spinal deformity. The first is bracing in young patients and the second is surgical correction for severe curve. Bracing is feasible for children with a Cobb angle between 20 degrees to 35 degrees, while surgical correction is the only choice if the Cobb angle is greater than 40 degrees. Recent surgical developments have led to good correction results with reduced operative scale through continuous spinal cord monitoring, evolution of spinal implants, and better perioperative and postoperative care. The newer spinal systems can produce 3-dimensional reconstruction of the deformity and maintain truncal balance afterwards. The newer implants are user-friendly and low-profile. The combined hook/screw application (hybrid) and the all-screw placement methods have become quite popular. With these methods, the correction rate is increased with reduced loss of correction at follow-up. Navigation systems facilitate accurate insertion of pedicle screws into the vertebral bodies, while video-assisted endoscopic instruments allow early ambulation. These methods are useful in cases of thoracic scoliosis. In the future, in order to minimize the operative scale and prevent deformity, important goals are elucidation of the real nature and the causes of scoliosis and restriction of the number of fusion levels by use of emerging technologies.

Bone Screws↗

PubMed1991

New concepts for the treatment of unstable angina: role for intravenous diltiazem.

The management of unstable angina continues to undergo rapid evolution as new therapies and techniques become increasingly available to clinicians. It appears that the pathogenesis of unstable angina involves endothelial factors (plaque rupture of fissure resulting in a complex coronary stenotic lesion) together with dynamic factors (including platelet aggregation, thrombosis, and altered coronary vasomotor tone), and therefore it is clear why the approach to the patient with acute coronary syndromes has become multidimensional. This article summarizes the current views of the pathogenesis of unstable angina, and the role that the above factors may play in the clinical syndrome of acute coronary insufficiency. In addition, the newer therapeutic approaches to the pharmacologic management of unstable angina are discussed, including the use of nitrates, heparin, aspirin, and beta-blockers. Increasingly, calcium-channel blockers are being utilized in the early pharmacologic management of unstable angina, particularly because these agents have a salutary effect on reducing increased coronary vasomotor tone, reducing myocardial oxygen demand while at the same time augmenting coronary blood flow, and decreasing platelet aggregation. Numerous small clinical trials have examined the role of intravenous calcium-channel-blocker therapy for the acute management of unstable angina. In particular, intravenous diltiazem appears to be both safe and efficacious in this setting, and may offer some advantages to intravenous nitroglycerin, when used in the Coronary Care Unit setting. Because diltiazem is a heart rate-lowering vasoactive drug, it may attenuate myocardial ischemia without causing reflex tachycardia associated with other vasoactive pharmacologic therapies. Several of these studies utilizing intravenous diltiazem in unstable angina are reviewed and discussed.

Angina, Unstable↗

PubMed1990

Comparison of low-dose aspirin and coronary vasodilators in acute unstable angina.

Episodic platelet activation has been shown to occur in unstable angina, and aspirin should have an important therapeutic role in the management of these patients. The response to aspirin alone or to aspirin in combination with vasodilators such as heparin and beta-blockers has been assessed in 41 patients with unstable angina. Therapy was added sequentially in the event of recurrence of transient myocardial ischemia. Patients were randomly assigned to two groups. Group 1 (21 patients) received an intravenous infusion of isosorbide dinitrate and oral diltiazem, and group 2 (20 patients) received intravenous aspirin (60 mg the first day and 20 mg on successive days). This dose of aspirin reduced serum thromboxane B2 from 160 +/- 88 ng/ml (mean +/- SD) to undetectable values (less than 6 ng/ml, p less than 0.01). If episodes of ischemic ST segment shift continued, the therapy of group 1 was added to that of group 2 or vice versa; if further ST segment changes were documented, intravenous heparin and oral beta-blockers were added; if episodes of myocardial ischemia persisted, urgent coronary arteriography and myocardial revascularization were performed. Nine patients in group 1 and six in group 2 (p = 0.8) had no further episodes of myocardial ischemia on their initial therapy; 12 additional patients had no further episodes when taking combined therapy of aspirin and vasodilators. Thus, the administration of aspirin alone was not superior to coronary dilators; 30% of all patients continued to have episodes of myocardial ischemia or had a myocardial infarction develop when heparin and beta-blockers were added. Myocardial infarction occurred in one patient on vasodilator therapy alone, in two on combined therapy, and in two on full therapy. These results suggest that in some patients, the stimulus to coronary thrombosis and vasoconstriction occasionally becomes so strong that it cannot be inhibited by certain antagonist drugs. The unstable tendency to continuation of ischemia or evolution to myocardial infarction is not related to the severity of the persisting stenosis. Those patients not promptly responding to combined therapy immediately from admission should have early coronary angiography and aggressive treatment.

Angina Pectoris↗

PubMed1989

Phylogenesis and nutrition.

The evolution of man is connected with a life-style of hunting and gathering, and with the development and use of tools. The success of tools promoted the evolution of brain, thinking and skills. The food sources--animal and plant--remained the same during the whole of evolution. But the proportions of foods, preferences, preparations and the attainability changed. Evolution was a process continuously based on omnivorous nutrition. Compared to modern nutrition, paleolithic nutrition is richer in animal protein, vitamins, calcium, potassium and fibre, and poorer in fat and sodium. Saccharose, lactose and alcohol play no roles. The quality of the fat is marked by a high proportion of polyunsaturated fatty acids. This shift from a paleolithic diet to a modern diet caused nutritional risks, partly responsible for the dramatic increase in modern chronic diseases of heart, circulation and so on. Man's metabolism works in a stable genetic frame, derived during phylogenesis. We have to adapt our nutritional behaviour to its tolerances or we may succumb to disease and premature death. While our paleolithic metabolism is overdone with modern nutrition, our psychological heritages press in the direction of overdoing.

Agriculture↗

PubMed1994

Limb-sparing therapy for soft tissue sarcomas.

Effective therapy for soft tissue sarcoma of the extremities continues in its lengthy evolution from mandatory amputation or radical compartment resection to multimodality limb salvage procedures. This current approach typically includes preoperative neoadjuvant systemic chemotherapy, followed by negative margin surgical resection in conjunction with radiotherapy. The scope and functional outcome of these resections has been markedly enhanced by the application of microvascular-dependent free tissue transfer techniques. Because of the rarity of this tumor system, problems in soft tissue sarcoma receive proportionally less attention. Nonetheless, the past year has witnessed several important advances in this field, as is discussed.

Amputation, Surgical↗

PubMed1994

[Canine parvovirus: recent knowledge of the origin and development of a viral pathogen].

Canine parvovirus (CPV) is a "new" virus that suddenly emerged in the mid 1970s. Antigenetically it is very similar to the long known feline panleukopenia virus (FPV). Soon after its appearance CPV was classified as a mutant of FPV. As with all "new" viruses, CPV continues to show active evolution, obvious by the appearance of new antigenic types. Interestingly, the new types, designated CPV-2a and CPV-2b, completely replaced the original type. This review summarizes the facts that are known about the emergence and evolution of CPV and discusses the relevance of the new antigenic types for the diagnosis of CPV and the vaccination against it.

Animals↗

PubMed1994

Restoration of the maxillary arch with a precision-milled double-bar prosthesis.

When restoring the challenging maxillary arch, no one treatment will serve all patients optimally. An open mind must be maintained, and the prosthetic evolution and creativity will continue. The ideal tooth position for each case should be determined prior to surgery in order to ensure optimum prosthetic results. This presentation and paper discuss the restoration of the maxillary arch. Impressions, soft tissue model, bar pattern, alloy selection, screw seating, and screw-retained suprastructure over infrastructure are presented and illustrated.

Dental Implantation, Endosseous↗

PubMed1997

Properties of intraepithelial neoplasia relevant to the development of cancer chemopreventive agents.

Cancer chemoprevention is concerned with the development of drugs or diet supplements that will avert the onset or stop the progression of the intraepithelial neoplasia which precedes invasive cancer. Two basic processes underlie the onset and development of intraepithelial neoplasia. First is genomic instability (often associated with chronic diffuse epithelial hyperplasia), which is the increased production of genomic structural variants due to unrepaired DNA breaks with secondary formation of abnormal structures, including "mutator" mutations in genes responsible for genomic stability, gene copy amplification or loss from DNA breakage-fusion-anaphase bridge cycles, unequal sister chromatid exchange, and accumulation of double minutes. Second is the development within an epithelium having genomic instability of multicentric neoplastic lesions that independently progress through each of the following processes at a continuously accelerating rate: clonal evolution, hyperproliferation, production of genomic structural variants, and apoptosis. Recommended chemoprevention strategies based on these mechanisms are (1) early diagnosis and treatment of genomic instability before the appearance of intraepithelial neoplasia, i.e., during the "predysplastic" or "premorphologic" phase, (2) development of multiple agents that block intralesional proliferation at steps along the "command" pathways of mitotic signal transduction and along the "execute" pathways of synthesis of daughter cell components, (3) development of nontoxic antiinflammatory agents, antioxidants, antimutagens, and proapoptotics, (4) avoidance of "clonal escape" through use of drug combinations, and (5) use of computer-assisted quantitative image analysis to assay modulation of surrogate endpoints in chemoprevention clinical trials.

Carcinoma in Situ↗

PubMed1998

Emergency medical kit for commercial airlines. Air Transport Medicine Committee, Aerospace Medical Association.

While it has been of general interest for a long time, the issue of a Medical Kit for Commercial Airlines is now close to the top of the priority list because of recent activities in Europe within the Joint Aviation Authorities (JAA) and in the United States at the Congressional Level. The Aerospace Medical Association (AsMA) requested its Air Transport Medicine Committee to review the situation and make recommendations for a basic medical kit for international airlines. After reviewing the contents of existing kits, and the limited amount of available data, a proposal was submitted to and accepted by the AsMA Council. This is just a beginning. The Air Transport Medicine Committee will continue to follow the evolution and periodically adapt the kit accordingly.

Aerospace Medicine↗

PubMed2003

The analysis of asthma control under a Markov assumption with use of covariates.

In studies of disease states and their relation to evolution, data on the state are usually obtained at in frequent time points during follow-up. Moreover in many applications, there are measured covariates on each individual under study and interest centres on the relationship between these covariates and the disease evolution. We developed a continuous-time Markov model with use of time-dependent covariates and a Markov model with piecewise constant intensities to model asthma evolution. Methods to estimate the effect of covariates on transition intensities, to test the assumption of time homogeneity and to assess goodness-of-fit are proposed. We apply these methods to asthma control. We consider a three-state model and we discuss in detail the analysis of asthma control evolution.

Asthma↗

PubMed2001

Potential sources of the 1995 Venezuelan equine encephalitis subtype IC epidemic.

Venezuelan equine encephalitis viruses (VEEV) belonging to subtype IC have caused three (1962-1964, 1992-1993 and 1995) major equine epizootics and epidemics. Previous sequence analyses of a portion of the envelope glycoprotein gene demonstrated a high degree of conservation among isolates from the 1962-1964 and the 1995 outbreaks, as well as a 1983 interepizootic mosquito isolate from Panaquire, Venezuela. However, unlike subtype IAB VEEV that were used to prepare inactivated vaccines that probably initiated several outbreaks, subtype IC viruses have not been used for vaccine production and their conservation cannot be explained in this way. To characterize further subtype IC VEEV conservation and to evaluate potential sources of the 1995 outbreak, we sequenced the complete genomes of three isolates from the 1962-1964 outbreak, the 1983 Panaquire interepizootic isolate, and two isolates from 1995. The sequence of the Panaquire isolate, and that of virus isolated from a mouse brain antigen prepared from subtype IC strain P676 and used in the same laboratory, suggested that the Panaquire isolate represents a laboratory contaminant. Some authentic epizootic IC strains isolated 32 years apart showed a greater degree of sequence identity than did isolates from the same (1962-1964 or 1995) outbreak. If these viruses were circulating and replicating between 1964 and 1995, their rate of sequence evolution was at least 10-fold lower than that estimated during outbreaks or that of closely related enzootic VEEV strains that circulate continuously. Current understanding of alphavirus evolution is inconsistent with this conservation. This subtype IC VEEV conservation, combined with phylogenetic relationships, suggests the possibility that the 1995 outbreak was initiated by a laboratory strain.

Amino Acid Sequence↗

PubMed2005

Rapid evolution of expression and regulatory divergences after yeast gene duplication.

Although gene duplication is widely believed to be the major source of genetic novelty, how the expression or regulatory network of duplicate genes evolves remains poorly understood. In this article, we propose an additive expression distance between duplicate genes, so that the evolutionary rate of expression divergence after gene duplication can be estimated through phylogenomic analysis. We have analyzed yeast genome sequences, microarrays, and transcriptional regulatory networks, showing a >10-fold increase in the initial rate for both expression and regulatory network evolution after gene duplication but only an approximately 20% rate increase in the early stage for protein sequences. Based on the estimated age distribution of yeast duplicate genes, we roughly estimate that the initial rate of expression divergence shortly after gene duplication is 2.9 x 10(-9) per year, whereas the baseline rate for very ancient gene duplication is 0.14 x 10(-9) per year. Relative expression rate tests suggest that the expression of duplicate genes tends to evolve asymmetrically, that is, the expression of one copy evolves rapidly, whereas the other one largely maintains the ancestral expression profile. Our study highlights the crucial role of early rapid evolution after gene/genome duplication for continuously increasing the complexity of the yeast regulatory network.

Evolution, Molecular↗

PubMedDate not supplied

Relationships between specialized cells, capillaries and intermediary cytofibrillary elements. XVth note. Biological evolution of the respiratory stereotype and subsystem in aquatic vertebrates.

The author continues in aquatic vertebrates the study of the evolution of the respiratory stereotype initiated in the XIIth note of this series and carried out in the light of the systemic conception (Bertalanffy), of Needham's theory of order in nature, and of the theory of biological stereotypes (Mârza, Repciuc, Eskenasy). The stability of some characters of the respiratory stereotype inherited by vertebrates from invertebrates is pointed out. The respiratory stereotype in vertebrates gradually passed from the respiration of water-dissolved oxygen through branchiae and skin, to the concomitant uptake of this form and of air oxygen (through buccopharyngeal formations, gaseous bladder or rudimentary lungs in osseous fishes), the double respiration (in Amphibia) and later the air respiration in Reptilia. The five steps of this gradual evolution are described, as well as the conditions of the evolution from crossopterygians to Tetrapoda (amphibians and reptiles).

Air↗