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 397 records · Page 22Linked to original sources
PubMed1983

Comparative and scaling aspects of heart and body weights with reference to blood supply of cardiac fibers.

Relative heart weight (RHW) differs in vertebrates with the ratio 1:20 between extremes (bottom bound fishes--Pleuronectidae--and birds). When plotting heart weight (HW) against body weight (BW) one obtains channels which contain not only vertebrates of the same classes (poikilotherms, small and big mammals and birds) but also animals belonging to different classes: tuna fish data are located in the "small mammalian channel" together with data of large tropical snakes while large mammals (upwards 4000 g) belong to the "bird channel". Reasons for such groupings are not clear and physical activity seems not to be the only reason. When comparing active and non active vertebrates one finds that the RHW is as a rule greater in physically more active poikilotherms and homoiotherms. The RHW is also higher in wild than in domesticated forms the differences appearing after weaning (wild vs laboratory rat). In spongy type of myocardium the growth of cardiac fibers results in restriction of the blood flow through lacunae and the contact between endothelial cells lining growing strands of musculature probably provokes formation of capillaries. The appearance of mixed type of myocardium (outer compact and inner spongy compartments) is not bound to the water to land transition since it occurs also in some fishes; it does not occur or is rare in amphibia and is frequent in reptiles. The compact outer layer comprises a different proportion of the cardiac wall volume (5-73%). Metabolic differences were described between cardiac cells in compact and spongy compartments.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2003

Sequential big endothelin plasma levels in heart transplant recipients during bridging therapy and after successful heart transplantation.

BACKGROUND: The purpose of this study was to investigate the impact of successful heart transplantation in patients with refractory heart failure receiving bridging therapy on sequential plasma levels of big endothelin, norepinephrine, atrial natriuretic peptide and aldosterone. METHODS: Fourteen patients (2 women, 12 men) accepted for heart transplantation were studied. All had severe chronic heart failure refractory to optimized oral therapy with angiotensin-converting enzyme inhibitors and furosemide, were in New York Heart Association functional Class IV, and had a left ventricular ejection fraction of <15%, Right heart catheterization was performed in all patients (cardiac index 1.9 +/- 0.1 liters/min. m(2), pulmonary capillary wedge pressure 30 +/- 2 mmHg, systemic vascular resistance index 2,827 +/- 253 dyn. s/cm(5). m(2)). As bridging therapy, patients received either prostaglandin E(1), prostaglandin E(1) and dobutamine or dobutamine alone as a continuous infusion. Neurohumoral variables were measured prior to bridging therapy and 3.5 months before and 7 and 10 months after successful heart transplantation. RESULTS: Big endothelin, norepinephrine and atrial natriuretic peptide plasma levels decreased from 7.4 +/- 2.9 fmol/ml, 1112 +/- 686 pg/ml and 366 +/- 312 pg/ml to 6.0 +/- 4.5 fmol/ml, 720 +/- 503 pg/ml and 198 +/- 160 pg/ml, respectively, after bridging therapy, and further to 2.1 +/- 0.9 fmol/ml (p < 0.00001 vs baseline), 527 +/- 31 pg/ml (p < 0.02 vs baseline) and 115 +/- 70 pg/ml (p < 0.03 vs baseline), respectively, after cardiac transplantation. Aldosterone plasma levels decreased from 242 +/- 220 pg/ml to 183 +/- 142 pg/ml during bridging therapy and increased after heart transplantation to 252 +/- 189 pg/ml. Plasma creatinine levels increased from 1.2 +/- 0.4 mg/dl at baseline to 1.4 +/- 0.2 mg/dl after transplantation (NS). CONCLUSIONS: The study suggests that excessive overproduction of big endothelin, atrial natriuretic peptide and norepinephrine is predominantly related to pump failure and, after cardiac transplantation, a moderate spillover of big endothelin persists. Its specific origin, however, remains to be elucidated. Furthermore, our data suggest a protective effect of prostaglandin E(1) on kidney function after heart transplantation.

Aged↗
PubMed1993

Scientific results from the Cosmic Background Explorer (COBE).

The National Aeronautics and Space Administration (NASA) has flown the COBE satellite to observe the Big Bang and the subsequent formation of galaxies and large-scale structure. Data from the Far-Infrared Absolute Spectrophotometer (FIRAS) show that the spectrum of the cosmic microwave background is that of a black body of temperature T = 2.73 +/- 0.06 K, with no deviation from a black-body spectrum greater than 0.25% of the peak brightness. The data from the Differential Microwave Radiometers (DMR) show statistically significant cosmic microwave background anisotropy, consistent with a scale-invariant primordial density fluctuation spectrum. Measurements from the Diffuse Infrared Background Experiment (DIRBE) provide new conservative upper limits to the cosmic infrared background. Extensive modeling of solar system and galactic infrared foregrounds is required for further improvement in the cosmic infrared background limits.

Journal Article↗
PubMed1993

Development of a neural network screening aid for diagnosing lower limb peripheral vascular disease from photoelectric plethysmography pulse waveforms.

An artificial neural network (ANN) was trained to classify photoelectric plethysmographic (PPG) pulse waveforms for the diagnosis of lower limb peripheral vascular disease (PVD). PPG pulses from the lower limbs, and pre- and post-exercise Doppler ultrasound ankle to brachial systolic blood pressure ratio measurements were obtained from patients referred to a vascular investigation laboratory. A single PPG pulse from the big toe of each leg was processed and normalized, and used as input data to the ANN. The ANN outputs represented the diagnostic classifications (normal, significant PVD and major PVD) and the ANN was trained with the ankle to brachial pressure indices (ABPI). The ANN structure consisted of an input layer (50 neuron units from the PPG pulse input), a single hidden layer (15 neurons) and an output layer (3 neurons for the PVD diagnoses). The back-propagation learning algorithm was used to train the ANN for 500 epochs with a PPG training set of pulses from 100 legs. Test data for network assessment comprised pulses from a further 50 legs (20 normal and 30 PVD, of which 15 were categorized as having major disease). A network sensitivity of 93% and specificity of 85% was achieved with respect to the Doppler ABPI standard, giving a diagnostic accuracy of 90%. The results of this study indicate that a neural network can be trained to distinguish between PPG pulses from normal and diseased lower limb arteries. The simplicity of PPG measurement and neural network classification holds promise for the screening of lower limb arterial PVD.

Humans↗
PubMed2001

The new chimaera: the industrialization of organ transplantation. International Forum for Transplant Ethics.

Clinical organ transplantation has evolved through advances in patient care in parallel with investigations in associated biologies. It has developed from a cottage industry to an important medical specialty driven increasingly by the availability of newer and more effective immunosuppressive drugs, and dependent on consistently close collaborations between university-based clinical scientists and the pharmaceutical industry. Particularly during the past decade, however, this industry has undergone striking changes, consolidating into huge multi-national corporations, each competing for patients, their doctors, and for support of the allied hospitals. Because of the growth of "Big Pharma," the relationship between academia and industry has changed. There have been many advantages to such mutually dependent interactions. A combination of university-based expertise and the specialized knowledge and resources of industry have produced important scientific gains in drug development. Commercial sponsorship of applied research has been crucial. The orchestration of multicenter controlled clinical drug trials has provided invaluable information about the effectiveness of newer agents. But there are also disadvantages of increasing concern. Indeed, the power of "Big Pharma" in many medical fields including transplantation is such that presentation of data can be delayed, adverse results withheld, and individual investigations hampered. Clinical trials may be protracted to stifle competition. Monetary considerations may transcend common sense. Several measures to enhance the clinical relationship between the pharmaceutical industry and those involved with organ transplantation are suggested, particularly the use of third party advisors in the production of clinical trials, support for more basic research and in the dissemination of results. In this way, the increasingly problematic phenomenon of commercialization of the field of transplantation can be tempered and controlled.

Drug Industry↗
PubMed2000

[Cancellation of scheduled surgery at a university hospital: an exploratory study].

In spite of the extensive available literature on surgery patients' preparation and on the performance of surgeries, the focus given to the cancellation of the surgical act has been quite restricted. This study aims at identifying the number of scheduled and cancelled surgeries as well as the services that are mostly affected by such cancellations and was carried out in the surgery service of a big public university hospital located in the metropolitan area of Fortaleza, Ceará. The data were collected through surgery registration books, daily maps of surgery schedules and from the files of patients scheduled for surgery from September to December, 1996. The gathered data were analyzed quantitatively and introduced in charts. The results demonstrate that from the 1,145 surgeries programmed in the selected period, 379 (33%) had been cancelled. The mostly prejudiced services were General Surgery, Ophthalmology, Head and Neck Surgery, Trauma and Orthopedics, Otorhinolaryngology, Nephrology and Renal Transplant, and Proctology. Further investigation in this area in order to know the determinant causes of surgery cancellation as well as the participation of nursing in the study of this problem are necessary.

Appointments and Schedules↗
PubMedDate not supplied

[Urinary calculi in myelomeningocele adults].

INTRODUCTION AND OBJECTIVES: The improvements in the management of newborns with myelomeningocele (MMC) have obtained a big increase in survival, allowing them to get longevity like never before, but data regarding urologic diseases during adult age are still missing. We herein evaluate the features of urinary lithiasis in adults born with MMC and the therapies used for its treatment. MATERIAL AND METHOD: We review 52 patients diagnosed at birth of MMC, between 18 and 40 years old, treated in our institution, with a mean follow-up of 6.7 years. RESULTS: 10 patients (19.2%) were diagnosed of urolithiasis. Three developed kidney calculi and one of them, with 7 more patients, developed bladder calculi (15.3%). The neurological level was < or = L2 in 3 cases, L2-S1 in 5, and > or = S1 in the other two. The type of neurogenic dysfunction of inferior urinary tract was multiple lesion of lower motor neurone in 6 cases, upper motor neurone in 1 case, multiple mixed lesion in 1 case and in case it was impossible to determine. Two patients had a bladder augmentation procedure and one of these with other 3 patients had a non-functional AMS-800 artificial urinary sphincter. Bladder stones were treated endoscopically in 14 procedures and by suprapubic cystolithotomy in 4 procedures, combined with removal of AMS-800 in 3 of them. One patient spontaneously passed a small stone. In one case, 2 ESWL and 2 percutaneous nephrolithotomies were needed. Three patients developed multiple recurrences during follow-up. CONCLUSIONS: Urinary lithiasis is common in adults with MMC. Some distinct features of these patients, together with their anatomical configuration and some therapies used in them, cause diagnostic, therapeutic and prophylaxis issues for the calculi they may develop.

Adolescent↗
PubMed1998

Integration of bioInformatics tools at the National University of Singapore (NUS).

In the past decade "Big Science" such as the Genome Project has generated an enormous amount of data in the life sciences. Concurrently, the synergy of this project with existing research has quickened the pace of biological discovery. But the major drawback that is beginning to be felt worldwide is the primitive level of organisation in the data accumulated. Without a proper framework or knowledge scaffold to hang and interconnect the various bits of data and information, the national knowledge-to-data ratio is declining rapidly. We are trying to serve a solution to this enigma by providing a World Wide Web (WWW) interface to Biosoftware and at the same time have come up with a database integration tool that can query heterogeneous, geographically scattered and disparate databases simultaneously. In this report we will talk about BioInformatics in general with specific reference to BioInformatics Centre (BIC) at the National University of Singapore.

Computational Biology↗
PubMed2006

Hepatic resection for colorectal metastasis: impact of tumour size.

BACKGROUND: Many colorectal liver metastasis patients are denied surgical resection on the basis of tumour size. The aim of this study was to explore the impact of metastasis size on modern liver resection. METHODS: Using a prospectively collected database, this was a retrospective analysis of 484 consecutive patients who underwent liver resection for colorectal liver metastases between 1993 and 2003. The cohort was divided into two groups: smaller metastases (< 8 cm) and larger metastases (> or = 8 cm). Those with larger metastases were then further stratified into big metastases (8-12 cm) and giant metastases (> 12 cm). Demographic, pathological, surgical technique and outcome data were compared between the groups. RESULTS: There were 88 (18%) patients with metastases measuring 8 cm or larger. There was an association between higher carcinoembryonic antigen (CEA) and cancer antigen (CA) 19-9 levels and larger metastases. The actuarial 5-year survival for patients with larger metastases was 38% compared with 42% for smaller metastases (not statistically significant). Patients with giant metastases had poorer overall and disease-free survival (both nonsignificant) compared with those with big metastases: 29% and 28% at 5 years, respectively. CONCLUSION: Patients with colorectal liver metastasis greater than 8 cm and up to 12 cm in size should not be treated differently from those with smaller lesions.

Adult↗
PubMed2004

[Biomarkers as prognostic factors in pulmonary arterial hypertension. Rationale and study design].

CURRENT SITUATION: Pulmonary arterial hypertension (PAH) is a serious disease. Its prognostic is based on the functional status quantified by the NYHA class and the 6-min walking test, and the hemodynamic data. The algorithms of treatment are solely based on the hemodynamic data and the functional status. The main objective is to test whether basal concentrations of isoprostanes, Big endotheline 1, ADMA, high sensitivity CRP, NT-Pro-BNP and cardiac troponin T are a 3-year prognostic factor in PAH using a combined criterion: death from any cause and pulmonary or cardiopulmonary transplantation. MATERIALS AND METHODS: This is a multicenter, prospective, prognostic, single blinded study (plasma and urinary samples being blinded). The study started in november 2003, running for 2 years, with a 3 year follow-up for each patient. The main inclusion criterion is PAH. The data analysis will use a multivariable Cox model, taking into account the functional and hemodynamic parameters. EXPECTED RESULTS: This study will determine whether any of the biomarkers tested provides additional prognostic information in PAH in addition to the functional and hemodynamic parameters.

Biomarkers↗
PubMedDate not supplied

[Myocardial infarct and geomagnetic disturbances: analysis of data on morbidity and mortality].

Relationships between different parameters of the geomagnetic activity and medical statistical data on myocardial infarction were investigated anew, because previous results in this field have been often inconsistent. The data are daily numbers of myocardial infarction incidence rates (15,543 cases) and number of deaths for infarction (3,065 cases), abstracted from registries of the 14 biggest hospitals of St. Petersburg (1989-1990). The analysis showed a statistically significant increase in myocardial infarction rate during big geomagnetic disturbances, defined by the days of the descending phase of cosmic ray Forbush decreases. An overall estimation of the average increase in infarction incidence rate during big geomagnetic storms, (10.5 +/- 1.2)%, has been computed by taking into account previous results [1-3]. In contrast, morbidity data did not show any significant correlation with geomagnetic disturbances. It was found also that the infarction incidence rate appears to be rather constant from Monday to Friday and to decrease sharply by a factor approximately 1.25 on Saturday-Sunday and mid-week festivities. This effect is associated with different exposure during work days and week-ends to man-made magnetic field environment mainly produced by electrified transport. Such effect was not observed in mortality data. The results and their methodological aspects are placed in the context of studies on possible health effects of low frequency magnetic fields both natural and man-made origin.

Data Interpretation, Statistical↗
PubMed1990

National cardiac registry allows outcomes comparison.

Quality, better patient outcomes and cost-containment are high on the healthcare agenda for the '90s. Comparison of clinical treatments over a broad range of episodes and variables can help physicians and researchers determine highly effective--and cost-effective--treatments. A national database, the Merged Cardiac Registry, has taken a big step toward that end.

Cardiovascular Diseases↗
PubMed2004

Time course of cII gene mutant manifestation in the liver, spleen, and bone marrow of N-ethyl-N-nitrosourea-treated Big Blue transgenic mice.

The time between treatment and the appearance of mutants (mutant manifestation time) is a critical variable for in vivo transgenic mutation assays. There are, however, limited data describing the optimal sampling time for detecting mutations in various tissues of mutagen-treated animals. In this study, we investigated the time course of cII gene mutant induction in the liver, spleen, and bone marrow of Big Blue transgenic mice treated with N-ethyl-N-nitrosourea (ENU). Six-month-old female mice were treated with a single dose (120 mg/kg) of ENU, and the animals were sacrificed, and the cII mutant frequencies (MFs) were determined at 1, 3, 7, 15, 30, and 120 days after the treatment. The MFs in the liver cII gene of ENU-treated mice increased with time after the treatment, while the MFs for concurrent controls remained constant. The liver cII MFs in ENU-treated mice were significantly increased at day 30 and 120 (p < 0.01), with the largest increase at day 120. The spleen cII MFs in ENU-treated mice were increased significantly at day 7 and later (p < 0.01), and reached a plateau at day 30. In the bone marrow, the cII MFs in ENU-treated mice were increased significantly at all sampling times (p < 0.01), with the maximum MF at day 3. These results confirm that the time after treatment required to reach the maximum MF is tissue specific, with the approximate time for the maximum ENU-induced cII MF response being: bone marrow, 3 days; spleen, 14-30 days; and liver, more than 30 days.

Alkylating Agents↗
PubMed1996

The genetic analysis of lacI mutations in sectored plaques from Big Blue transgenic mice.

The Big Blue lacI transgenic rodent assay, which uses the lambda LIZ/lacI gene as the target for mutation, provides a convenient short-term assay for the study of mutation in vivo [Kohler et al. (1991): Proc Natl Acad Sci USA 88:7958-7962; Provost et al. (1993): Mutat Res 288:133-149). However, the interpretation of data from transgenic animal assays is sometimes complicated by mutants that appear as sectored mutant lambda plaques. These mutants can form a significant fraction of the mutant plaques [Hayward et al. (1995): Carcinogenesis 16:2429-2433]. Thus, in order to accurately determine in vivo mutant frequencies and mutational specificities, it is necessary to score sectored plaques and partition them from the rest of the data. In this study, the specificity of mutation in sectored plaques recovered from untreated and UVB-treated Big Blue mouse skin was analyzed and compared to mutations recovered from lambda LIZ/lacI grown on the Escherichia coli host. The mutational spectra of sectored plaques from untreated and UVB-treated mice were remarkably similar to each other and resembled those recovered from the lambda LIZ/lacI phage plated directly on E. coli. Both the sectored mutants and those recovered in lambda LIZ/lacI phage differed from the spectra of spontaneous mutants in E. coli and in Big Blue mouse skin. While sectored mutants from UVB-treated mouse skin and lambda LIZ/lacI mutants were also different from spontaneous mutants recovered from Big Blue liver, these was little difference between sectored mutants from untreated mouse skin and spontaneous liver mutants (P = 0.07). The mutational spectra of sectored plaques is thus largely consistent with their origin as spontaneous mutations arising in vitro during growth of the lambda LIZ/lacI shuttle vector DNA on the E. coli host, although the potential contribution from lesions in mouse DNA being expressed ex vivo in the E. coli host cannot be excluded.

Animals↗