Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “big data”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15Linked to original sources
PubMed1992

[Erythrophagocytosis and pigment cells of the amphibian liver].

The ultrastructure of Kupffer liver cells of adult frogs collected in winter and Kupffer cells during amphibian metamorphosis when larval red cells are replaced by adult red cells were investigated. It was revealed that Kupffer cells of the animals investigated had very large size and consisted of either the whole senescent erythrocyte or many phagosomes with small electron dense granules resembling ferritin. Phagosomes are oriented among numerous vesicular and vermiform profiles of agranular endoplasmic reticulum and big Golgi complex. Comparing our morphologic evidence with data of the literature that granules of melanin are synthesized and localized in frog liver Kupffer cells, we came to conclusion that pigment cells were formed as a result of erythrophagocytosis and therefore they were the depo of catabolism products. The comparison of functions of melano-macrophage centers of fish liver and of pigment cells of amphibia liver were discussed.

Animals↗
PubMed2005

Sneddon's syndrome as a disorder of small arteries with endothelial cells proliferation: ultrastructural and neuroimaging study.

We report a 18-year-old female patient with livedo reticularis and neurological disturbances. CT scan showed two big ischemic focuses in the pons, moreover MRI revealed small disseminated ischemic focuses in the pons and deep structures of both brain hemispheres. MRA demonstrated no changes in the big extracranial and intracranial arteries. Since the clinical data and neuroimaging results suggested Sneddon's syndrome, the skin and skeletal muscle biopsy was taken to examine. The immunohistochemical and ultrastructural investigations of the skin biopsy revealed a significant reduction of the lumen of the capillaries and small to medium-sized arteries. Cells surrounding the vascular lumen, frequently with multilayer arrangement and their nuclei placed perpendicularly to the lumen, were CD31, CD34, and sporadically SMA positive. At the ultrastructural level, these proliferating cells showed typical features of endothelial cells: abundant intermediate filaments and Weibel-Palade bodies. Between the endothelial cells some junctions were detached as well in the capillaries as in the small arteries. The smooth muscle cells of the small arteries were electron denser than usual and their cytoplasmic protrusions penetrated to the endothelial cells. The ultrastructural picture of some vessels with a considerably narrow lumen was typical of vessels newly formed during angiogenesis. Neuroimaging including TC, MRI, MRA besides histological, immunohistochemical and ultrastructural evaluation may be useful for diagnosis of Sneddon's syndrome.

Adolescent↗
PubMed1987

[What is researched in Spain on childhood accidents and poisonings? A descriptive study of the last 11 years].

Situation of research done in childhood accidents an accidental poisoning in Spain must be known to plan future studies. Authors studied 131 publications obtained from IME (Indice Medico Español) data bank (1974-1984). Only 62 of them were epidemiological studies or reviews. Most of them were based on hospital data. Authors were mainly pediatricians who lived in big cities and had articles published in pediatric journals. They conclude that there are few studies on epidemiology of accidents in general populations and on how to prevent them.

Accidents↗
PubMed1983

[Relation between population morbidity and atmospheric pollution in several industrial regions of the country].

Population morbidity rate was studied in some regions of chemical industry, petro-chemical and metallurgical industry as well as in some big towns of the country according to the data on the appeals for medical aid for a 7-year long period (1972-1978). A correlation was established between the type and degree of atmospheric pollution in the polluted regions and morbidity rate, according to nozological entities, both among infant and adult population.

Adolescent↗
PubMed1984

[Impact of reflux on the kidney].

Description of the reflux nephropathy. Pyelonephritis lesions are undoubtedly linked to the vesico-ureteric reflux. The role of the intra-renal reflux ( Hodson ) and the Big Bang Theory ( Ransley ) are discussed as the data from animal experiments. The role of the sterile reflux and of the segmental hypoplasia is relatively less important. The actual management of vesico-ureteric reflux treatment is questioned.

Child↗
PubMed1996

Neocytoapheresis in the treatment of polycythemia vera.

In absence of thrombocytosis, periodic bloodlettings represent the elective therapy of polycythemia vera. In the present study we tested if neocytoapheresis, a method able to remove large quantities of younger, and then bigger red cells could represent an alternative therapeutic choice in these patients. We found that the employment of neocytoapheresis produced a remarkable delay in the time of procedures with a mean interval of 100 +/- 55 days. The mean value of hematocrit before neocytopheresis is resulted statistically different in comparison with the hematocrit after the procedure (p = 0.0001). The reticulocyte count is resulted higher in apheresis product in comparison with the blood control measured before procedure (p = 0.0001). In the same way, the mean corpuscular volume in the collection bags was higher than the volume measured before neocytoapheresis (p = 0.0095). We did not find any variation about the mean values of white blood cells and platelets before and after neocytoapheresis in the patients examined. These preliminary data seem to underline a better withdrawal of big size cells by this technique suggesting the efficacy of neocytoapheresis in the treatment of polycythemia vera.

Blood Cell Count↗
PubMed1995

Endothelin-1 and big endothelin-1 increase in human endometrium during menstruation.

OBJECTIVES: Although the physiologic and pathologic roles of endothelin-1 in reproduction have been investigated, little is known about human uterine tissue levels. We studied the levels of immunoreactive endothelin-1 and immunoreactive big endothelin-1 in human endometrium and myometrium during each menstrual phase. STUDY DESIGN: Materials were obtained at hysterectomy (endometrium, n = 33; myometrium, n = 27). We measured immunoreactive endothelin-1 and immunoreactive big endothelin-1 by radioimmunoassay and performed an immunohistochemical study of the tissue. Data were analyzed by the Mann-Whitney U test. RESULTS: We detected larger amounts of immunoreactive endothelin-1 and immunoreactive big endothelin-1 in the endometrium than in the myometrium throughout the menstrual, proliferative, and secretory phases. Endometrial immunoreactive endothelin-1 and immunoreactive endothelin-1 were significantly increased in the menstrual phase (endothelin-1 68.8 +/- 23.3 pg/mg protein, n = 5, p < 0.005; big endothelin-1 45.2 +/- 5.7 pg/mg protein, n = 5, p < 0.003) compared with the other phases (endothelin-1 30.7 +/- 9.5 and 30.5 +/- 14.0 pg/mg protein; big endothelin-1 19.9 +/- 6.7 and 24.1 +/- 7.4 pg/mg protein). Immunohistochemistry demonstrated that the endometrial stromal cells were positive for antiendothelin monoclonal antibody only in the premenstrual and menstrual phases. CONCLUSION: Levels of immunoreactive endothelin-1 and immunoreactive big endothelin-1 are different in each type of uterine tissue and in each phase of the menstrual cycle. These changes may indicate some role of endothelin-1 in menstruation.

Antibodies↗
PubMed2005

Preliminary survey of the mayflies (Ephemeroptera) and caddisflies (Trichoptera) of Big Bend Ranch State Park and Big Bend National Park.

The mayfly (Insecta: Ephemeroptera) and caddisfly (Insecta: Trichoptera) fauna of Big Bend National Park and Big Bend Ranch State Park are reported based upon numerous records. For mayflies, sixteen species representing four families and twelve genera are reported. By comparison, thirty-five species of caddisflies were collected during this study representing seventeen genera and nine families. Although the Rio Grande supports the greatest diversity of mayflies (n=9) and caddisflies (n=14), numerous spring-fed creeks throughout the park also support a wide variety of species. A general lack of data on the distribution and abundance of invertebrates in Big Bend National and State Park is discussed, along with the importance of continuing this type of research.

Animals↗
PubMed1999

Hierarchical subcomponents of the Big Five personality factors: a cross-language replication.

An ideal structural representation of personality attributes would include more than just broad-bandwidth factors. Specific subcomponents help define broad factors while enhancing the fidelity of the representation. There has been no consensus with regard to the necessary specific subcomponents of the Big Five. This problem was addressed by analyzing 2 representative lexical data sets, one involving English adjectives and the other involving German adjectives. Large samples (Ns of 636 and 775) were used in classifying a selection of 500 adjectives in each language by Big Five domains, and within each domain and language, the terms were factor analyzed with promax rotation. Ratings by 22 bilinguals of correspondence between the adjectives in English and German factors indicated 18 distinct content themes common to personality description in the 2 languages. The 18 subcomponents delineate necessary features of a more finely faceted measurement model for the lexical Big Five factors.

Adolescent↗
PubMed1995

Analysis of endogenous human endothelin peptides by high-performance liquid chromatography and mass spectrometry.

The three isoforms of both endothelin (ET) and big ET are not readily distinguishable by radioimmunoassay (RIA) or enzyme-linked immunosorbent assay (ELISA) alone. We have previously used high-performance liquid chromatography (HPLC) linked with RIA to determine ET isoforms in various tissue extracts, and cell supernatants. Our aim was to confirm that the isoforms of ET secreted by human umbilical vein endothelial cells (HUVECs) are ET-1 and big ET-1, using HPLC linked to electrospray mass spectrometry (ESI-MS). Authentic synthetic peptide standards were used to obtain the specific ions for ET isoforms and to calculate their retention times on the HPLC system. ET-1, [Met7]-sulfoxy ET-1, ET-2, ET-3, and big ET-1 could all be separated by HPLC and by specific ions on ESI-MS. Pooled supernatant (500 ml) from 50 cultures of HUVECs was applied first to an anti-C-terminal ET-1 immunoaffinity column and then to an anti-C-terminal big ET-1 immunoaffinity column. The eluates were solid phase-extracted and then injected onto an HPLC system linked to ESI-MS. Peaks of mass intensity at the specific ions and retention times corresponding to ET-1, [Met7]-sulfoxy ET-1, and big ET-1 were found in these eluates. However, no signal was present for ET-2 or ET-3. These data confirm that HUVECs in culture produce ET-1, [Met7]-sulfoxy ET-1, and big ET-1.

Cells, Cultured↗
PubMed2005

Mutagenicity testing with transgenic mice. Part II: Comparison with the mouse spot test.

The mouse spot test, an in vivo mutation assay, has been used to assess a number of chemicals. It is at present the only in vivo mammalian test system capable of detecting somatic gene mutations according to OECD guidelines (OECD guideline 484). It is however rather insensitive, animal consuming and expensive type of test. More recently several assays using transgenic animals have been developed. From data in the literature, the present study compares the results of in vivo testing of over twenty chemicals using the mouse spot test and compares them with results from the two transgenic mouse models with the best data base available, the lacI model (commercially available as the Big Blue(R) mouse), and the lacZ model (commercially available as the Mutatrade mark Mouse). There was agreement in the results from the majority of substances. No differences were found in the predictability of the transgenic animal assays and the mouse spot test for carcinogenicity. However, from the limited data available, it seems that the transgenic mouse assay has several advantages over the mouse spot test and may be a suitable test system replacing the mouse spot test for detection of gene but not chromosome mutations in vivo.

Journal Article↗
PubMed2004

Mining mass spectra for diagnosis and biomarker discovery of cerebral accidents.

In this paper we try to identify potential biomarkers for early stroke diagnosis using surface-enhanced laser desorption/ionization mass spectrometry coupled with analysis tools from machine learning and data mining. Data consist of 42 specimen samples, i.e., mass spectra divided in two big categories, stroke and control specimens. Among the stroke specimens two further categories exist that correspond to ischemic and hemorrhagic stroke; in this paper we limit our data analysis to discriminating between control and stroke specimens. We performed two suites of experiments. In the first one we simply applied a number of different machine learning algorithms; in the second one we have chosen the best performing algorithm as it was determined from the first phase and coupled it with a number of different feature selection methods. The reason for this was 2-fold, first to establish whether feature selection can indeed improve performance, which in our case it did not seem to confirm, but more importantly to acquire a small list of potentially interesting biomarkers. Of the different methods explored the most promising one was support vector machines which gave us high levels of sensitivity and specificity. Finally, by analyzing the models constructed by support vector machines we produced a small set of 13 features that could be used as potential biomarkers, and which exhibited good performance both in terms of sensitivity, specificity and model stability.

Adult↗
PubMed1999

Canopy photosynthesis of sugar maple (Acer saccharum): comparing big-leaf and multilayer extrapolations of leaf-level measurements.

A comparison is made between a big-leaf model (i.e., without details of the canopy profile) and two multilayer models (i.e., with details of the canopy profile) to estimate daily canopy photosynthesis of a sugar maple (Acer saccharum Marsh.) stand. The first multilayer model uses the distribution of leaf area by leaf mass per unit area (LMA) classes, the observed relationships between the parameters of a photosynthesis-irradiance curve and LMA, and the relationship between relative irradiance and LMA to estimate canopy photosynthesis. When compared with this model, the big-leaf model underestimates daily canopy photosynthesis by 26% because of an assumed proportionality between photosynthetic capacity and relative irradiance, a proportionality that is inconsistent with our data. The bias induced by this assumption is reduced when the big-leaf model is compared with the second multilayer model which, in addition to the assumptions made for the first multilayer model, accounts for the sunlit and shaded fractions of leaf area. The residual bias is almost eliminated when the big-leaf model is run using a weekly averaged irradiance. It is likely, however, that this is the result of a compensating bias that, in this particular case, compensates for the initial bias introduced by the proportionality assumption. It is also shown that canopy photosynthesis can be represented by spatially inexplicit multilayer models that use leaf mass per area as a covariable to describe leaf characteristics and environment. Such models represent an interesting alternative to the biased big-leaf approach.

Journal Article↗
PubMed1997

Amniotic membranes as prosthetic material: experimental utilization data of a rat model.

BACKGROUND/PURPOSE: Prosthetic materials are applied for closing big tissue defects, the repair of traumatized organs, or hernias. Because nonabsorbable synthetic materials are rigid, possess a defined and unchangeable size, and foreign body reaction (FBR) may occur, biological materials may be an alternative. METHODS: In experimental studies in rats the authors implanted the fetal parts of the human amniotic membranes and examined the utilization and FBR induced in a standardized model. In addition amnion (AM) was combined with vicryl-net (VN) for higher implant stability. Fifteen, 30 and 90 days after implantation, macroscopic appearance was examined, and light microscopy and immunohistology testing of the specimens were performed. RESULTS: Adhesions to parenchymal organs and omentum were present irrespective of the side facing the abdominal cavity. AM induced a rapid FBR, which diminished with time. Chorion (CH) and parts of the AM were resorbed within the examined period after infiltration with recipient cells and neovascularisation. The combined implant, AM, and VN showed best results because disadvantages of one material could be compensated for by the advantages of the other. CONCLUSION: The studies show that AM, in its anatomic definition, combined with VN proves to be a safe and reliable prosthetic material for the use in tissue defects.

Amnion↗
PubMed2006

Linking proactive personality and the Big Five to motivation to learn and development activity.

The authors investigated links between the Big Five, proactive personality, and motivation to learn. Web-based survey data were collected at 2 points in time from 183 employees of a financial services firm. Results showed that proactive personality was, only in part, a composite of Big Five facets, which accounted for 26% of its variance. Structural equation modeling results demonstrated that proactive personality, openness, extraversion, and conscientiousness predicted motivation to learn. In addition, motivation to learn was positively related to objectively assessed development activity. Proactive personality, extraversion, and openness had significant indirect links to development activity. Hierarchical regression results suggested that proactive personality had significant incremental validity in the prediction of motivation to learn over all relevant Big Five facets.

Adult↗
PubMedDate not supplied

How big are educational and racial fertility differentials in the U.S.?

Using pooled data from the 1980, 1985, 1990 and 1995 CPS and 1988 and 1995 NSFG surveys, we show that shifts in fertility timing have occurred disproportionately for the more educated and for whites (compared to the less educated and to African Americans). Such timing shifts imply that the underlying period quantum of fertility is considerably higher for college-educated women and for whites than suggested by the standard total fertility rate. Applying the Bongaarts-Feeney model (1998), we decompose observed racial and educational differences in age-order-specific fertility rates and TFR into tempo and quantum components. We find that a modest part of educational differences and a substantial part of racial difference in period fertility can be attributed to differential changes in tempo. Analysis by race and education shows a clear interaction: higher fertility among African Americans is confined to the less educated.

Adolescent↗