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At least 1,063 records · Page 59Linked to original sources
PubMed1995

Hexamethylmelamine is a potent inducer of deletions in male germ cells of Drosophila melanogaster.

Chemotherapy-related second tumors constitute a matter of concern in cancer treatment. Therefore, it is of great interest to elucidate the mechanisms by which cytostatic drugs exert their mutagenic and/or carcinogenic activity besides the anticancer effect and the possible relationship among them. A useful and informative approach to this problem is the analysis of the mutation spectra induced by these drugs in eukaryotic organisms. Sequence analysis of the mutations induced by hexamethylmelamine, a crosslinking agent extensively used in the treatment of ovarian cancer, in male germ cells of Drosophila was conducted using the v locus as reporter gene. Both intra-locus and multi-locus deletions were induced whereas based changes were almost absent. Thus, it is proposed that deletions are likely to be involved in the generation of second malignancies in hexamethylmelamine-treated patients. It has to be stressed that systems, such as v, capable of efficiently recovering mutations caused by big losses of DNA, should be used for the study of mutational spectra induced by cross-linking agents.

Altretamine↗
PubMed1990

Viewpoint: academic medical centers--it is time for a declaration of values.

America's academic medical centers have become big businesses, competing, diversifying, and pursuing new economic relationships with physicians and the private sector. Corporate values and ethics are being tested, and leaders of some institutions say they are troubled by emerging trends.

Academic Medical Centers↗
PubMed2004

Productive efficiency and its determinants in the Finnish Public Dental Service.

OBJECTIVE: Our objective was to investigate the cost efficiency of the Public Dental Service (PDS), which, until 2000, was responsible for organising dental care for children and younger adults born in 1956 and later. METHODS: Input and output data and information on various organisational and environmental characteristics were collected from 228 municipal PDS units in Finland. First, non-parametric data envelopment analysis (DEA) was employed to assess efficiency. In the second stage, econometric Tobit analysis was used to explore various predictors of cost efficiency, technical efficiency and allocative efficiency. As input in the DEA model we used personnel full-time equivalents and material and other costs expressed in monetary terms, and as output we used the number of treated patients. RESULTS: The study showed big differences in cost efficiency between the PDS units studied. The average cost inefficiency was 30%. Approximately two-thirds of the observed cost inefficiency was because of technical inefficiency and one-third because of allocative inefficiency. High state-subsidy levels, and a high proportion of young patients predicted inefficiency, and young population and low socioeconomic conditions in the municipality predicted efficiency. The results also indicated that many PDS units could have improved allocative efficiency by increasing the relative numbers of auxiliaries in relation to dentists. On the other hand, some units were too small to employ full-time dental hygienists efficiently. CONCLUSIONS: In the Finnish PDS, there are uncommitted resources that could be reallocated so as to improve overall efficiency.

Adolescent↗
PubMed1996

Will we like tomorrow's giants?

The healthcare industry is buying into the benefits of being big. Merger and acquisition deals hit a pace of 2.4 per day among all types of providers during the first half of the year. But critics believe the time has come to rein in the rampant consolidation.

Antitrust Laws↗
PubMed1978

Case study: cost/benefit analysis of clinical education--radiologic technology, College A-Hospital B.

The Clinical Allied Health Education Center, Grand Rapids, Michigan, supported by Ferris State College, Big Rapids, Michigan, under Contract No. 1-AH-44106 with the Department of Health, Education and Welfare, designed a model for the clinical education of allied health personnel. Research concerning the cost of clinical education was a necessary part of the model design process. The primary purpose of this case study was to determine, in dollar terms, the cost or benefit to Hospital B, using available data, or data which could be developed with little effort by the hospital. The study breaks down the component costs into determinable factors, and assigns a dollar value to each. A value is also assigned to that portion of the student's activities that produced revenue for the hospital. Expenses related to the production of revenue by students are calculated and applied against said revenue in accordance with the matching principle. The result when revenue and expense were matched was net benefit of $46, 186 to Hospital B.

Cost-Benefit Analysis↗
PubMedDate not supplied

[Solid pseudo-papillary tumor of the pancreas: a case of a big abdominal mass in a young woman].

Solid pseudo-papillary tumor of the pancreas is a rare tumor that occurs predominantly in young women. It often presents as a big abdominal mass whose preoperative diagnosis appears to be difficult. It is a low- grade malignancy tumor and surgery is the mainstay of treatment. The Authors report the case of a 40 year-old woman with an abdominal mass supposed to origin from the mesenterium, diagnosed as a solid pseudo-papillary tumor of the pancreas after histological examination and treated by enucleation. Moreover literature data about epidemiology, histogenesis, diagnosis and treatment are analysed.

Adult↗
PubMed1981

[Obesity in children. I. The prevalence of obesity in the Netherlands].

A review is presented of the prevalence of obesity among apparently healthy 8 year old schoolchildren, based on the findings of the National Nutrition Council's cross-sectional surveys, periodically performed in the Netherlands with 3 year intervals in the period 1960-1977. When clinical obesity is defined as more than 25 pct fat mass of total body-weight in young children, 3 to 4 pct obesity occurs in smaller towns or villages in the peripheral areas of the country and 4 to 7 pct in big cities. When 20 pct fat mass is the criterium for the lower limit of obesity, the prevalence for thick including obese children varies from 10 to 13 pct in small towns versus 14 to 20 pct in big cities. The prevalence of obesity thus defined tends to be lower from 1968 onwards. From various other surveys in the Netherlands similar reports are published, mentioning 2 pct of clinical obesity among 6 to 7 year olds up to 4 and 7 pct among 10 year olds and 8-10 pct among school attending adolescents of 15 and 16 years old. There are no reliable data on the prevalence of obesity among infants and toddlers in this country. A second part of this interview on obesity among children will relate to the possible effects of childhood obesity for obesity in later life.

Adult↗
PubMedDate not supplied

Urban mortality--race or place?

Several concomitant trends have occurred in American society in the 20th century. First, life expectancy has improved overall, and the gap between blacks and whites has narrowed. Second, as the nature of the economy has changed from rural agrarian to urban postindustrial, there have been fundamental changes in population residential patterns, with most Americans now living in metropolitan areas. Within metropolitan areas, blacks have become concentrated in poor inner cities as whites have moved to the more affluent suburbs. Black mortality rates are higher in big cities than elsewhere, and appear to be directly related to the proportion of blacks in those cities. Black-white mortality ratios, however, are lower in cities of medium size than in either very large or small cities. At the national level age-adjusted mortality ratios between blacks and whites are associated with different causes of death; but only limited cause-specific mortality data are available for large cities. Understanding and ameliorating social conditions that lead to elevated black mortality in U.S. cities will require more information at the municipal level than is currently available.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Complement receptor type 3 mediates phagocytosis and killing of Listeria monocytogenes by a TNF-alpha- and IFN-gamma-stimulated macrophage precursor hybrid.

Previous work demonstrated that engagement of complement receptor type 3 (CR3) was required for inflammatory peritoneal macrophages to phagocytose and kill the facultative intracellular bacterium Listeria monocytogenes. The experiments described here tested the role of CR3 in phagocytosis and killing of Listeria by a clonal population of TNF-alpha/IFN-gamma-stimulated macrophage precursor hybrids. Stimulation with TNF-alpha and IFN-gamma increased CR3 expression 20-fold and induced a big increase in phagocytic activity. Phagocytosis and killing of Listeria by these cells were inhibited when bacteria were opsonized with complement-depleted serum or by incubation of the macrophages with anti-CR3 mAb. Furthermore, cytokine-stimulated macrophages could not kill Listeria opsonized with heat-inactivated anti-Listeria antiserum, indicating that macrophage receptors which mediate phagocytosis do not necessarily promote bactericidal activity. These data suggest that upregulation of CR3 and CR3-mediated phagocytosis are mechanisms by which TNF-alpha and IFN-gamma stimulate nonphagocytic, nonbactericidal macrophage precursors to kill intracellular bacterial pathogens.

Animals↗
PubMed1998

Dopamine metabolism in the striatum of hemiparkinsonian model rats with dopaminergic grafts.

To investigate dopamine (DA) levels as well as DA metabolism by which the striatal DAergic grafts may bring the functional recovery to hemiparkinsonian model rats, a microdialysis study was performed in the striatum, and an autoradiographic analysis for DA transporter was made. In hemiparkinsonian model rats, the concentrations of DA, dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in striatal perfusates, decreased considerably (less than 5%, of control levels). In grafted rats that showed motor recovery, the concentration of DA recovered to almost control level, and DOPAC and HVA to about 20% of controls' suggesting that the rate of DA metabolism is low. L-DOPA loading to grafted rats induced a big release of DOPAC and HVA, thus the DOPAC/DA ratio was close to that of the controls'. Methamphetamine loading increased the concentration of DA but did not change the level of DOPAC and HVA. Haloperidol loading increased DA, DOPAC and HVA. [3H]mazindol binding that reflects the activity of the DA transporter decreased considerably in hemiparkinsonian model rats, but it reappeared more or less in grafted rats. Data indicated that in grafted striatum, the extracellular DA level is almost normal level while the rate of DA metabolism is low. By L-DOPA loading, the grafts show the capacity to synthesize, release and metabolize DA and then the DOPAC/DA ratio is normalized. Responses to methamphetamine and haloperidol, as well as the results of the autoradiographic study suggest that the grafts are under a good feedback regulation of DA metabolism.

3,4-Dihydroxyphenylacetic Acid↗
PubMed2004

Large-scale grid-enabled lattice Boltzmann simulations of complex fluid flow in porous media and under shear.

Well-designed lattice Boltzmann codes exploit the essentially embarrassingly parallel features of the algorithm and so can be run with considerable efficiency on modern supercomputers. Such scalable codes permit us to simulate the behaviour of increasingly large quantities of complex condensed matter systems. In the present paper, we present some preliminary results on the large-scale three-dimensional lattice Boltzmann simulation of binary immiscible fluid flows through a porous medium, derived from digitized X-ray micro-tomographic data of Bentheimer sandstone, and from the study of the same fluids under shear. Simulations on such scales can benefit considerably from the use of computational steering, and we describe our implementation of steering within the lattice Boltzmann code, called LB3D, making use of the RealityGrid steering library. Our large-scale simulations benefit from the new concept of capability computing, designed to prioritize the execution of big jobs on major supercomputing resources. The advent of persistent computational grids promises to provide an optimal environment in which to deploy these mesoscale simulation methods, which can exploit the distributed nature of computer, visualization and storage resources to reach scientific results rapidly; we discuss our work on the grid-enablement of lattice Boltzmann methods in this context.

Journal Article↗
PubMed2002

[Completed suicide and depression in the elderly].

The aim of the study was to present problems of completed suicide and depression in the elderly. Postmortem examinations were conducted in the Institute of Forensic Medicine of the Jagiellonian University. The analysis included cases of completed suicide in adults, from which all the cases of individuals aged over 65 who in the years 1998, 1999, and 2000 committed suicide within the area of Kraków the City were selected for the present study. The examined group consisted of 92 individuals ranging in age from 65 to 89 years, including 34 females and 58 males. The mean age was 72.5 for the entire group. 44.5% of the subjects had resided in a big city (Kraków); the remainder of the group had resided in villages and towns around Kraków. 57.6% of the subjects committed suicide by hanging, 16.3%--by falling from a height, and 13%--by drowning. In the majority of cases (77.2%), the suicide was committed at home. In 17 cases (18.5%), the post mortem revealed the presence of alcohol. As regards somatic diseases in the examined population, the data from the anamnesis (often incomplete) indicate frequent occurrence of cardiovascular diseases. 43.5% of the subjects, who committed suicide, had been treated for mental disorders, mainly for depression, organic brain disorders, and alcohol addiction. 17 of the subjects (18.5%) had previously attempted to commit suicide. The above results indicate that a typical representative of the elderly committing suicide is a septuagenarian residing in the country or in a small town, and most typically committing suicide by hanging at home. The attention must be paid to the high number of mental disorders, especially depression, detected among both male and female subjects. The close relation between suicide and depression in the elderly is an important guideline on suicide prevention programs and therapy of psychogeriatric patients.

Aged↗
PubMed2000

[Study of appropriate surveillance of health appraisal for communities].

A study to determine the appropriate surveillance of health appraisal for communities was made using individual data for deaths in 1992-1996 in Maniwa County (population 51,000), individual data of medical examinations from 1995 to 1997 in Maniwa and other county (population 24,000), rate for people receiving medical examinations from 1983 to 1996 in Maniwa County and life table data for Japanese males in 1995. The results obtained were as follows: (1) The total YPLL (Years of Potential Life Lost) rate was reversely correlated with the proportion of people who had a medical examination as compared to the total population, with a time lag of about 6 years (P < 0.05). It can be concluded that past health appraisal may influence future indicators of death with a time lag of about 6 years. (2) In the case of calculation of Years of Potential Life Lost rate (YPLL rate = sum of ¿target age - (death age + 0.5) between n1 and n2 ages¿/population), if the target age is close to the n2, the number of deaths close to the n2 have a possibility of very small evaluation to influence of number of these near to n1. Therefore a target age must be set up some years above n2. (3) There is a peak point (about 90 years) among 0 and 99 years old for the YPLL rate in life tables for Japanese males in 1995 using the target age of 100. On the other hand, using a target age of 120 there was a linear increasing from about 75 age with no peak. Then, if YPLL rate with a target age of 100 is used, there may be big different values among n2 before peak age and after peak age. (4) To perform appropriate surveillance of health appraisal for communities (population size: 1000-2000), two indicators must be used. One is a simple rate for number of death peoples of some diseases to total population or of peoples who have an abnormal indicator on some medical examinations to total number of peoples who have a medical examination, in which case that person's age is not be considered. The other is Age-Adjusted YPLL or YPHL (Years of Potential Health Lost) rate not using a data of standard population that have been showed next equation. A target age should be set at 120, as a maximum age of human life rather than 80 or 100. Age - Adjusted T(n1 - n2) YPLL rate(by Inoue) [formula: see text] T: A target age (value of 120 is appropriate), n1: youngest individual age, n2: oldest age, i; individual age between n1 and n2, pi: population (in the case of YPHL rate, it shows a number of peoples receiving medical examination) at age of i, Qi: number of death on some disease (number of peoples who have an abnormal indicator on some item of medical examination) at age of i.

Adult↗
PubMed1995

Distribution of Big tau in the central nervous system of the adult and developing rat.

The diversity of neuronal morphology and function is correlated with specific expression of various microtubule associated proteins (MAPs). One of the major neuronal MAPs, tau, has multiple isoforms formed as a result of alternative splicing and phosphorylation that are differentially expressed during development. Big tau is a high molecular weight isoform that contains an additional large exon (4a) and is expressed primarily by neurons in the peripheral nervous system (PNS). We cloned the complete 4a exon in an expression vector, isolated the recombinant protein and produced antibodies specific to Big tau that were used to localize Big tau in the developing spinal cord and in the adult central nervous system (CNS). In developing spinal cord, Big tau is first expressed in the central projections of the dorsal root ganglia neurons and in motor neurons at embryonic day 18 and postnatal day 2, respectively. In the adult rat CNS, almost all neurons that extend processes into the PNS express Big tau, including all cranial nerve motor nuclei and central processes of most sensory ganglia; of these ganglia, only the bipolar neurons of the olfactory, vestibular and spiral ganglia did not express Big tau. Retinal ganglion cells are the only CNS neurons, whose processes remain entirely within the CNS, that express high levels of Big tau. The limited and specific distribution of Big tau is consistent with a role in stabilizing microtubules in axons that are subjected to great shear forces.

Animals↗
PubMed1995

A permanent human cell line (EA.hy926) preserves the characteristics of endothelin converting enzyme from primary human umbilical vein endothelial cells.

Purification of endothelin converting enzyme (ECE) from endothelial cells has been hindered by the difficulty in obtaining primary endothelial cells in large quantity. We therefore tested transformed human umbilical vein endothelial cells (EA.hy926) for ECE activity. Our data clearly demonstrate that this transformed cell line preserves the ECE properties of the primary cell line. These include: (i) one sharp activity optimum at neutral pH; (ii) characteristics typical of a metalloprotease; (iii) IC50 value for phosphoramidon of 1.8 microM (2.7 microM for HUVEC); (iv) no inhibition by captopril and thiorphan, inhibitors of angiotensin converting enzyme and neutral endopeptidase 24.11. The enzyme showed a substrate specificity for big ET-1:big ET-2:big ET-3 in a ratio of 40:2.5:1. This report presents evidence that a permanent human endothelial cell line, EA.hy926, preserves the ECE activity of HUVEC and is useful for the study of ECE and its regulation of ET-1 production.

Animals↗
PubMed2002

Simulating the formation of cosmic structure.

A timely combination of new theoretical ideas and observational discoveries has brought about significant advances in our understanding of cosmic evolution. Computer simulations have played a key role in these developments by providing the means to interpret astronomical data in the context of physical and cosmological theory. In the current paradigm, our Universe has a flat geometry, is undergoing accelerated expansion and is gravitationally dominated by elementary particles that make up cold dark matter. Within this framework, it is possible to simulate in a computer the emergence of galaxies and other structures from small quantum fluctuations imprinted during an epoch of inflationary expansion shortly after the Big Bang. The simulations must take into account the evolution of the dark matter as well as the gaseous processes involved in the formation of stars and other visible components. Although many unresolved questions remain, a coherent picture for the formation of cosmic structure is now beginning to emerge.

Astronomy↗
PubMedDate not supplied

Endothelin concentration in plasma of healthy dogs and dogs with congestive heart failure, renal failure, diabetes mellitus, and hyperadrenocorticism.

Plasma concentrations of endothelin (ET)-1 and -3 were determined simultaneously in dogs with various pathophysiological conditions, because these peptides may display different pharmacological profiles. The study pays special attention to the characterization of plasma ET immunoreactivity (ET-IR), using high-pressure liquid chromatography (HPLC) analysis with off-line detection by radio-immunoassay (RIA). In most sick dogs evaluated total plasma ET-1-IR concentration did not differ from that of healthy dogs. However, HPLC analysis of their total plasma ET-1-IR revealed distinct ET-IR profiles. Big-ET-1, which is barely detectable in control dogs, does represent the predominant ET in sick dogs. Regardless of the pathophysiological conditions, considerable amounts of high-molecular weight ET-1-IR, most likely aggregated ET-material, was found consistently. With respect to ET-3, we constantly observed moderately increased concentrations, though no major difference of molecular pattern was evident between healthy and sick dogs. The data show a distinct regulation of ET-1 and ET-3 in dogs. Furthermore, specific molecular forms of ET-IR were found to occur in various diseases. The endothelins may therefore prove to be of diagnostic importance in the pathophysiology of vascular diseases.

Adrenal Cortex Diseases↗
PubMed2005

Corticofugal feedback for collicular plasticity evoked by electric stimulation of the inferior colliculus.

Focal electric stimulation of the auditory cortex, 30-min repetitive acoustic stimulation, and auditory fear conditioning each evoke shifts of the frequency-tuning curves [hereafter, best frequency (BF) shifts] of cortical and collicular neurons. The short-term collicular BF shift is produced by the corticofugal system and primarily depends on the relationship in BF between a recorded collicular and a stimulated cortical neuron or between the BF of a recorded collicular neuron and the frequency of an acoustic stimulus. However, it has been unknown whether focal electric stimulation of the inferior colliculus evokes the collicular BF shift and whether the collicular BF shift, if evoked, depends on corticofugal feedback. In our present research with the awake big brown bat, we found that focal electric stimulation of collicular neurons evoked the BF shifts of collicular neurons located near the stimulated ones; that there were two types of BF shifts: centripetal and centrifugal BF shifts, i.e., shifts toward and shifts away from the BF of stimulated neurons, respectively; and that the development of these collicular BF shifts was blocked by inactivation of the auditory cortex. Our data indicate that the collicular BF shifts (plasticity) evoked by collicular electric stimulation depended on corticofugal feedback. It should be noted that collicular BF shifts also depend on acetylcholine because it has been demonstrated that atropine (an antagonist of muscarinic acetylcholine receptors) applied to the IC blocks the development of collicular BF shifts.

Acoustic Stimulation↗