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PubMed2003

The genesis of neurosurgery and the evolution of the neurosurgical operative environment: part I-prehistory to 2003.

Despite its singular importance, little attention has been given to the neurosurgical operative environment in the scientific and medical literature. This article focuses attention on the development of neurosurgery and the parallel emergence of its operative setting. The operative environment has, to a large extent, defined the "state of the art and science" of neurosurgery, which is now undergoing rapid reinvention. During the course of its initial invention, major milestones in the development of neurosurgery have included the definition of anatomy, consolidation of a scientific basis, and incorporation of the practicalities of anesthesia and antisepsis and later operative technical adjuvants for further refinement of action and minimalism. The progress, previously long and laborious in emergence, is currently undergoing rapid evolution. Throughout its evolution, the discipline has assimilated the most effective tools of modernity into the operative environment, leading eventually to the entity known as the operating room. In the decades leading to the present, progressive minimalization of manipulation and the emergence of more refined operative definition with increasing precision are evident, with concurrent miniaturization of attendant computerized support systems, sensors, robotic interfaces, and imaging devices. These developments over time have led to the invention of neurosurgery and the establishment of the current state-of-the-art neurosurgical operating room as we understand it, and indeed, to a broader definition of the entity itself. To remain current, each neurosurgeon should periodically reconsider his or her personal operative environment and its functional design with reference to modernity of practice as currently defined.

History, 15th Century↗

PubMed2000

Implantation of rat insulinoma cell line into cyclosporine treated rats. Effect of the in vivo environment on beta-cell specific gene expression.

BACKGROUND: Transplantation of engineered beta cell-derived lines is a promising modality for cell-based therapy of diabetes mellitus. The in vivo environment and antirejection and other medications may have significant effects on the differentiation and proliferation of the transplanted beta cells, thus affecting their function. The effect of the in vivo environment on expression of genes encoding proteins involved in insulin production, secretion, and glucose sensing were analyzed in the RIN 104638 cell line. METHODS: RIN 104638 cells, were used for s.c. implantation in cyclosporine treated rats and for parallel in vitro culture. The differential expression of the insulin, PDX-1, GLUT-2, and glucokinase genes were assessed by quantitative reverse transcription polymerase chain reaction. RESULTS: The in vivo environment of cyclosporine-treated rats, preserved most of the differentiated characteristics of the implanted cells. Insulin and glucokinase gene expression were maintained at high levels, although GLUT-2 expression decreased. This was in contrast to the substantial decrease of all the three genes expression when cultured in vitro. Cyclosporine treatment reduced insulin and GLUT-2 gene expression in in vitro culture. CONCLUSIONS: Beta cell implantation in cyclosporine-treated rats induces alteration in expression of genes pivotal to insulin production and secretion and the glucose sensing abilities. The normal in vivo environment improves the implanted b cell function by increasing the insulin gene expression and content. Furthermore, it reverses some of the dedifferentiating changes caused by the in vitro culture. This may have a positive effect on the therapeutic efficiency of this cell line.

Actins↗

PubMed1995

A survey of occupational health professionals' preventive pulmonary practices and worksite environments: development and initial findings.

This article describes the development of a worksite survey to evaluate a continuing medical education (CME) program to improve preventive pulmonary practices and worksite environments of occupational physicians and nurses, and baseline findings from the survey. The two-part instrument assessed individual counseling practices for preventing lung disease and worksite environments. Eighty-one occupational physicians and nurses completed the survey before the CME program. Reliability coefficients (Cronbach's alpha) were calculated for five test subsections: smoking counseling (.72), workplace hazards (.70), environmental programs (.78), workplace environment (.94), and smoking policies (.91). Baseline findings indicated that 80% of respondents reported that their employees/patients were exposed to various workplace hazards. This instrument can be used to evaluate occupational health professionals' performance and worksite environments and may be useful for evaluating change over time or following a training program for occupational health professionals.

Education, Continuing↗

PubMed2004

Children at risk: risk factors for low back pain in the elementary school environment.

STUDY DESIGN: A prevalence survey of 101 randomly selected elementary schools in the Israel Central District. OBJECTIVES: To identify and describe risk factors for low back pain that exist in the elementary school environment. SUMMARY OF BACKGROUND DATA: Recent surveys report a high prevalence of low back pain in children and adolescents that increases with age, with a correlation between low back pain in adolescence and that experienced in adulthood. Environmental risk factors have been associated with the development of low back pain in children. Because of the significant amount of time children spend in their school environment, risk factors need to be identified in this environment. METHODS: A questionnaire, completed by school nurses, measured risk factors among 10,000 children in elementary schools in Israel. These included backpack and student weight, the availability of storage facilities, the appropriateness of chair and desk height to student height, seating arrangements during frontal lessons, and physical activity at recess. RESULTS: Between 30% and 54% of students carried >15% of their body weight. Nearly 15% of the first graders and 20% of sixth graders had inappropriate chairs. In 74% of the classes, students sat with their side facing the teacher and in 35% students sat with their backs. In 6% of schools, no physical activity is offered at recess. CONCLUSIONS: Shortcomings were found in all areas investigated. There is an urgent need for health promotion programs to increase awareness and reduce risks in the school environment.

Body Weight↗

PubMed2000

Dynamics and changing environments in highly optimized tolerance

Highly optimized tolerance (HOT) is a mechanism for power laws in complex systems based on the robust design of systems in uncertain environments. Once the system, the environment, and the optimization scheme have been specified, the HOT state is fixed and corresponds to the set of measure zero (typically a single point) in the configuration space which minimizes a cost function U. Here we explore the U-dependent structures in configuration space which are associated with departures from the optimal state. We introduce dynamics, quantified by an effective temperature T, such that T=0 corresponds to the original HOT state, while T-->infinity corresponds to completely random configurations. More generally, T defines the range in state space over which fluctuations are likely to be observed. In a fixed environment fluctuations always raise the average cost. However, in a time-dependent environment, mobile configurations can lower the average U because they adjust more efficiently to changes.

Journal Article↗

PubMed2005

Geometric nature of the environment-induced Berry phase and geometric dephasing.

We investigate the geometric phase or Berry phase acquired by a spin half which is both subject to a slowly varying magnetic field and weakly coupled to a dissipative environment (either quantum or classical). We study how this phase is modified by the environment and find that the modification is of a geometric nature. While the original Berry phase (for an isolated system) is the flux of a monopole field through the loop traversed by the magnetic field, the environment-induced modification of the phase is the flux of a quadrupolelike field. We find that the environment-induced phase is complex, and its imaginary part is a geometric contribution to dephasing. Its sign depends on the direction of the loop. Unlike the Berry phase, this geometric dephasing is gauge invariant for open paths of the magnetic field.

Journal Article↗

PubMed2005

Technical guidelines for enhancing privacy and data protection in modern electronic medical environments.

Raising awareness and providing guidance to on-line data protection is undoubtedly a crucial issue worldwide. Equally important is the issue of applying privacy-related legislation in a coherent and coordinated way. Both these topics gain extra attention when referring to medical environments and, thus, to the protection of patients' privacy and medical data. Electronic medical transactions require the transmission of personal and medical information over insecure communication channels like the Internet. It is, therefore, a rather straightforward task to capture the electronic medical behavior of a patient, thus constructing "patient profiles," or reveal sensitive information related to a patient's medical history. The consequence is clearly a potential violation of the patient's privacy. We performed a risk analysis study for a Greek shared care environment for the treatment of patients suffering from beta-thalassemia, an empirically embedded scenario that is representative of many other electronic medical environments; we capitalized on its results to provide an assessment of the associated risks, focusing on the description of countermeasures, in the form of technical guidelines that can be employed in such medical environments for protecting the privacy of personal and medical information.

Computer Communication Networks↗

PubMed2002

Thermodynamic environments in proteins: fundamental determinants of fold specificity.

To investigate the relationship between an amino acid sequence and its corresponding protein fold, a database of thermodynamic stability information was assembled as a function of residue type from 81 nonhomologous proteins. This information was obtained using the COREX algorithm, which computes an ensemble-based description of the native state of proteins. Dissection of the COREX stability constant into its fundamental energetic components resulted in 12 thermodynamic environments describing the tertiary architecture of protein folds. Because of the observation that residue types partitioned unequally between these environments, it was hypothesized that thermodynamic environments contained energetic information that connected sequence to fold. To test the significance of this hypothesis, the thermodynamic stability information was incorporated into a three-dimensional-to-one-dimensional scoring matrix, and simple fold recognition experiments were performed in a manner such that information about the fold target was never included in the scoring. For 60 out of 81 fold targets, the correct sequence for the target scored in the top 5% of 3858 decoy sequences, with Z-scores ranging from 1.76 to 12.23. Furthermore, a scoring matrix assembled from the residues of 40 nonhomologous all-alpha proteins was used to thread sequences against 12 nonhomologous all-beta protein targets. In 10 of 12 cases, sequences known to adopt the native all-beta structure scored in the top 5% of 3858 decoy sequences, with Z-scores ranging from 1.99 to 7.94. These results indicate that energetic information encoded by thermodynamic environments represents a fundamental property of proteins that underlies classifications based on secondary structure.

Algorithms↗

PubMed2001

Modeling of the structural features of integral-membrane proteins reverse-environment prediction of integral membrane protein structure (REPIMPS).

The Profiles-3D application, an inverse-folding methodology appropriate for water-soluble proteins, has been modified to allow the determination of structural properties of integral-membrane proteins (IMPs) and for testing the validity of solved and model structures of IMPs. The modification, known as reverse-environment prediction of integral membrane protein structure (REPIMPS), takes into account the fact that exposed areas of side chains for many residues in IMPs are in contact with lipid and not the aqueous phase. This (1) allows lipid-exposed residues to be classified into the correct physicochemical environment class, (2) significantly improves compatibility scores for IMPs whose structures have been solved, and (3) reduces the possibility of rejecting a three-dimensional structure for an IMP because the presence of lipid was not included. Validation tests of REPIMPS showed that it (1) can locate the transmembrane domain of IMPs with single transmembrane helices more frequently than a range of other methodologies, (2) can rotationally orient transmembrane helices with respect to the lipid environment and surrounding helices in IMPs with multiple transmembrane helices, and (3) has the potential to accurately locate transmembrane domains in IMPs with multiple transmembrane helices. We conclude that correcting for the presence of the lipid environment surrounding the transmembrane segments of IMPs is an essential step for reasonable modeling and verification of the three-dimensional structures of these proteins.

Bacteriorhodopsins↗

PubMed2006

Impact of recurrent changes in the work environment on nurses' psychological well-being and sickness absence.

AIM: This paper is a report of a study of how the occurrence and appraisal of recurrent changes in the work environment of hospital nurses affect psychological well-being (i.e. job satisfaction, eustress and distress) and absence through illness. BACKGROUND: Many researchers have demonstrated the impact of major organizational changes on employees' psychological well-being, but only a few have focused on the permanent consequences in work conditions. In a contemporary healthcare setting, an increased number of recurrent operational changes has become a normal characteristic of nurses' work environment. Specific work situations have frequently been associated with occupational stress, whereas employees' appraisal of recurrent changes as stressors and their relation to psychological well-being and health outcomes (i.e. sickness absence) have been dismissed. METHODS: A cross-sectional questionnaire survey was conducted in 2003 with 2094 Registered Nurses in 10 general hospitals. Logistic regressions were used to investigate the impact on psychological well-being and prospectively measured rates of sickness absence (frequency and duration). RESULTS: The occurrence of changes in the work environment (in the past 6 months) had had a negative impact on staff psychological well-being. Nurses who had been confronted with changes scored statistically significantly higher for distress. Changes appraised as threatening were negatively related to job satisfaction and eustress, and positively related to distress and sickness absence (frequency and duration). Changes appraised as challenging were positively related to job satisfaction and eustress but had no impact on distress and sickness absence. CONCLUSION: Future research should take into consideration the impact of the occurrence and appraisal of recurrent changes in the work environment of healthcare employees (i.e. Registered Nurses) on psychological well-being and sickness absence. This should also be considered by managers when dealing with these nursing workforce issues.

Absenteeism↗

PubMed2004

Food vacuole-associated lipid bodies and heterogeneous lipid environments in the malaria parasite, Plasmodium falciparum.

The malaria parasite Plasmodium falciparum induces a sixfold increase in the phospholipid content of infected erythrocytes during its intraerythrocytic growth. We have characterized the lipid environments in parasitized erythrocyte using the hydrophobic probe, Nile Red. Spectral imaging with a confocal microscope revealed heterogeneous lipid environments in parasite-infected erythrocytes. An insight into the nature of these environments was gained by comparing these spectra with those of triacylglycerol/phospholipid emulsions and phospholipid membranes. Using this approach, we identified a population of intensely stained particles of a few hundred nanometers in size that are closely associated with the digestive vacuole of the parasite and appear to be composed of neutral lipids. Electron microscopy and isolation of food vacuoles confirmed the size of these particles and their intimate association respectively. Lipid analysis suggests that these neutral lipid bodies are composed of di- and triacylgycerols and may represent storage organelles for lipid intermediates that are generated during digestion of phospholipids in the food vacuole. Mono-, di- and triacylglycerol suspensions promote beta-haematin formation, suggesting that these neutral lipid bodies, or their precursors, may also be involved in haem detoxification. We also characterized other compartments of the infected erythrocyte that were stained less intensely with the Nile Red probe. Both the erythrocyte membrane and the parasite membrane network exhibit red shifts compared with the neutral lipid bodies that are consistent with cholesterol-rich and cholesterol-poor membranes respectively. Ratiometric imaging revealed more subtle variations in the lipid environments within the parasite membrane network.

Animals↗

PubMed2003

Self-efficacy and its interrelation with family environment and metabolic control in Turkish adolescents with type 1 diabetes.

OBJECTIVE: To explore the relationship between self-efficacy, family environment (cohesion and organization) and metabolic control. RESEARCH DESIGN AND METHODS: A total of 100 adolescents with diabetes were assessed on a single occasion. Eligibility criteria were an age range of 11-18 yr, diagnosis of type 1 diabetes of at least 1 yr duration, and ability to complete the questionnaire unaided. Adolescents completed self-efficacy and family environment questionnaires. Metabolic control was assessed by HbA1c. Statistical analysis was performed using Statistical Package for the Social Sciences (SPSS) Version 10.0. Independent paired t-tests and Pearson's correlation coefficient were used as test methods. RESULTS: Boys and girls were comparable on self-efficacy, and self-efficacy scores were quite satisfactory for both boys and girls. There was a significant positive correlation between self-efficacy and family cohesion in girls, but self-efficacy was not related to the family environment (cohesion and organization) and metabolic control in the total sample. CONCLUSION: In the present study, there was no relationship between self-efficacy, family environment, and metabolic control in the total sample, but in girls, self-efficacy and family cohesion was positively correlated.

Adolescent↗

PubMed1998

The therapeutic environment of psychiatric hospitals in Japan: a comparison of medical welfare facilities for senile dementia.

With the dual purpose of protecting the human rights of mentally disordered persons and promoting their social rehabilitation, the newly revised Mental Health Law was enacted in July 1987. It has brought significant change in that it has shifted Japanese mental health care from a hospital-based to a community-based system. Consequently, the therapeutic environment in the psychiatric hospitals has been changing from a closed to an open one. Recently, the amenity of hospital environments has been discussed. Furthermore, in the revision of medical fees of April 1994 the government established the long-term care ward system, which is a good indication of the changing nature of psychiatric institutions in Japan. I will report on the current therapeutic environment in Japanese psychiatric hospitals, and will also compare it with the care environment in facilities for healthcare services for the aged (and/or senile dementia) and special nursing homes for the aged.

Aged↗

PubMed2005

Ferroplasma and relatives, recently discovered cell wall-lacking archaea making a living in extremely acid, heavy metal-rich environments.

For several decades, the bacterium Acidithiobacillus (previously Thiobacillus) has been considered to be the principal acidophilic sulfur- and iron-oxidizing microbe inhabiting acidic environments rich in ores of iron and other heavy metals, responsible for the metal solubilization and leaching from such ores, and has become the paradigm of such microbes. However, during the last few years, new studies of a number of acidic environments, particularly mining waste waters, acidic pools, etc., in diverse geographical locations have revealed the presence of new cell wall-lacking archaea related to the recently described, acidophilic, ferrous-iron oxidizing Ferroplasma acidiphilum. These mesophilic and moderately thermophilic microbes, representing the family Ferroplasmaceae, were numerically significant members of the microbial consortia of the habitats studied, are able to mobilize metals from sulfide ores, e.g. pyrite, arsenopyrite and copper-containing sulfides, and are more acid-resistant than iron and sulfur oxidizing bacteria exhibiting similar eco-physiological properties. Ferroplasma cell membranes contain novel caldarchaetidylglycerol tetraether lipids, which have extremely low proton permeabilities, as a result of the bulky isoprenoid core, and which are probably a major contributor to the extreme acid tolerance of these cell wall-less microbes. Surprisingly, several intracellular enzymes, including an ATP-dependent DNA ligase have pH optima close to that of the external environment rather than of the cytoplasm. Ferroplasma spp. are probably the major players in the biogeochemical cycling of sulfur and sulfide metals in highly acidic environments, and may have considerable potential for biotechnological applications such as biomining and biocatalysis under extreme conditions.

Acids↗

PubMed2006

Heavy use of prophylactic antibiotics in aquaculture: a growing problem for human and animal health and for the environment.

The accelerated growth of finfish aquaculture has resulted in a series of developments detrimental to the environment and human health. The latter is illustrated by the widespread and unrestricted use of prophylactic antibiotics in this industry, especially in developing countries, to forestall bacterial infections resulting from sanitary shortcomings in fish rearing. The use of a wide variety of antibiotics in large amounts, including non-biodegradable antibiotics useful in human medicine, ensures that they remain in the aquatic environment, exerting their selective pressure for long periods of time. This process has resulted in the emergence of antibiotic-resistant bacteria in aquaculture environments, in the increase of antibiotic resistance in fish pathogens, in the transfer of these resistance determinants to bacteria of land animals and to human pathogens, and in alterations of the bacterial flora both in sediments and in the water column. The use of large amounts of antibiotics that have to be mixed with fish food also creates problems for industrial health and increases the opportunities for the presence of residual antibiotics in fish meat and fish products. Thus, it appears that global efforts are needed to promote more judicious use of prophylactic antibiotics in aquaculture as accumulating evidence indicates that unrestricted use is detrimental to fish, terrestrial animals, and human health and the environment.

Animals↗

PubMed2005

Crown architecture in sun and shade environments: assessing function and trade-offs with a three-dimensional simulation model.

Sun and shade environments place markedly different constraints on the photosynthetic performance of plants. Leaf-level photosynthetic responses to sun and shade have been extensively investigated, whereas there has been much less research on the functional role of crown architecture in these environments. This paper focuses on the role of architecture in maximizing light capture and photosynthesis in shaded understories and in minimizing exposure to excess radiation in open high light environments. Understanding these contrasting roles of architecture is facilitated by application of a three-dimensional structural-functional model, Y-plant. Surveys of understory plants reveal a diversity of architectures but a strong convergence at only modest light-capture efficiencies because of significant self-shading. Simulations with Psychotria species revealed that increasing internode lengths would increase light-capture efficiencies and whole plant carbon gain. However, the costs of the additional required biomechanical support was high, which, in terms of relative growth rates, would override the advantage provided by higher light-capture efficiencies. In high light environments, leaf angles and self-shading provide structural photoprotection, minimizing potential damage from photoinhbition. Simulations reveal that without these structural protections photoinhibition of photosynthesis is likely to be much greater with daily carbon gain significantly reduced.

Computer Simulation↗

PubMed1997

Relations between family environment and adjustment outcomes in young adults with spina bifida.

Thirty-two young adults with spina bifida completed a questionnaire (Family Environment Scale) assessing their perceptions of family social environment while growing up. Additionally, subjects responded to a structured interview addressing their current employment status, residential situation, level of community mobility, and extent of social activity. Multiple logistic regression analyses were used to assess the relation between family environment and adjustment as a young adult. With this limited sample, results indicated that perceived family environment explained variance in employment, community mobility, and social activity as an adult, even beyond that explained by lesion level and intelligence. Regression coefficients showed positive relations between perceived family encouragement of independence and achievement and young adult outcomes. In contrast, perceived moral/religious emphasis of the family and degree of family involvement with intellectual/cultural activities evidenced negative relations with the measures of young adult adjustment.

Adaptation, Psychological↗

PubMed1996

Health promotion needs of students in a college environment.

A significant amount of the mortality and morbidity experienced by Americans of all ages today is preventable. Research directed toward the identification of health promotion needs of traditional students in college environments may contribute to the development and implementation of programs and activities that assist students to adopt healthy lifestyle behaviors throughout their life spans. The purpose of this descriptive survey study was to identify the health promotion needs of traditional students in a college environment. More specifically, the research question was: What are the health promotion needs of traditional students in a college environment? Subjects were male and female students, 18-21 years of age, and enrolled in a full-time (minimum of 12 hours) program of study at one of two college campuses in a metropolitan southern city. One of these was a 2-year state-affiliated community college and the other was a private 4-year coeducation university. A randomized sample of 148 subjects was computed. Results of this study emphasize the distinctive individual and group health promotion needs of traditional students in a college environment. Identification of the health promotion needs of this population will enable health care providers to develop interventions to assist students in developing healthy lifestyle behaviors.

Adolescent↗