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PubMed1992

Preliminary results on speaker-dependent variation in the TIMIT database.

A set of phonetic studies based on analysis of the TIMIT speech database is presented. Using a database methodological approach, these studies detail new results in speaker-dependent variation due to sex and dialect region of the talker including effects on stop release frequency, speaking rate, vowel reduction, flapping, and the use of glottal stop. TIMIT was found to be fertile ground for gathering acoustic-phonetic knowledge having relevance to the phonetic classification and recognition goals for which TIMIT was designed, as well as to the linguist attempting to describe regularity and variability in the pronunciation of read English speech.

Databases, Factual↗
PubMed1998

Health surveillance: an operational imperative?

Many recent operations have highlighted the problem of hazard exposure in troops. This is a difficult area since it depends upon both post-deployment and possibly mid-deployment health surveillance and crosses the traditional limits of occupation and public health medicine. Health surveillance is itself a term which straddles occupational and public health medicine. For the military population at risk on operations, a combined approach is required incorporating the separate activities of needs and risk assessments. There is an existing vehicle to develop this approach using the new J95 methodology. Equally, a system of data access crossing medical and personnel records is necessary. The important requirement is that health surveillance is included in pre-deployment planning. Only by this method can adequate resources and significance be accorded to appropriate health surveillance strategies both during and following an operation as required.

Health Services Needs and Demand↗
PubMed2005

Aberrant DNA methylation as a cancer-inducing mechanism.

Aberrant DNA methylation is the most common molecular lesion of the cancer cell. Neither gene mutations (nucleotide changes, deletions, recombinations) nor cytogenetic abnormalities are as common in human tumors as DNA methylation alterations. The most studied change of DNA methylation in neoplasms is the silencing of tumor suppressor genes by CpG island promoter hypermethylation, which targets genes such as p16(INK4a), BRCA1, and hMLH1. There is a profile of CpG island hypermethylation according to the tumor type, and genes silent by methylation represent all cellular pathways. The introduction of bisulfite-PCR methodologies combined with new genomic approaches provides a comprehensive spectrum of the genes undergoing this epigenetic change across all malignancies. However, we still know very little about how this aberrant DNA methylation "invades" the previously unmethylated CpG island and how it is maintained through cell divisions. Furthermore, we should remember that this methylation occurs in the context of a global genomic loss of 5-methylcytosine (5mC). Initial clues to understand this paradox should be revealed from the current studies of DNA methyltransferases and methyl CpG binding proteins. From the translational standpoint, we should make an effort to validate the use of some hypermethylated genes as biomarkers of the disease; for example, it may occur with MGMT and GSTP1 in brain and prostate tumors, respectively. Finally, we must expect the development of new and more specific DNA demethylating agents that awake these methyl-dormant tumor suppressor genes and prove their therapeutic values. The expectations are high.

Animals↗
PubMed1995

The challenge facing migration research: a case for greater awareness.

The author critically examines an article by Keith Halfacree and Paul Boyle, in which the authors made a case for a biographical approach to migration research. "My point of contention--incredulous disbelief might be more accurate--stems from their conclusion that the biographical approach should be the ¿new' methodological base for an improved paradigm in migration studies."

Demography↗
PubMed2006

Ranked prediction of p53 targets using hidden variable dynamic modeling.

Full exploitation of microarray data requires hidden information that cannot be extracted using current analysis methodologies. We present a new approach, hidden variable dynamic modeling (HVDM), which derives the hidden profile of a transcription factor from time series microarray data, and generates a ranked list of predicted targets. We applied HVDM to the p53 network, validating predictions experimentally using small interfering RNA. HVDM can be applied in many systems biology contexts to predict regulation of gene activity quantitatively.

Cell Line, Tumor↗
PubMed1984

Computer-assisted morphometry and microdensitometry of transmitter- identified neurons with special reference to the mesostriatal dopamine pathway. Methodological aspects.

New morphometrical and microdensitometrical approaches for evaluation of transmitter-identified neurons in the central nervous system have been developed. These rely at the presynaptic level on the use of immunocytochemistry and at the postsynaptic level on the use of receptor autoradiography. The immunocytochemical analysis involves the indirect immunofluorescence method and the indirect immunoperoxidase method utilizing cryostat and vibratome sections, respectively. In the postsynaptic analysis cryostat sections and tritium-sensitive film were employed. A block diagram representation of the system of the image analyzer used and its connection with its host computer is given. Furthermore, flow charts of the original software developed by our group in presented. The morphometrical analysis has been performed on coronal sections of rat brain resulting in determinations of cell body and cell group parameters. Based on this information, objective criteria have been introduced to assess the existence of a cell group of transmitter-identified neurons in a three-dimensional frame and to give a morphometrical description of this group in the space. Moreover, new quantitative approaches to describe the dendritic and terminal fields have been introduced and for the first time in this type of morphometrical analysis, the Lorenz curves and the Gini index have been utilized in the description of the pattern of dendritic and terminal networks. By means of these morphometrical approaches it became possible to analyze topological and biochemical heterogeneities within cell groups defined in the rostrocaudal frame. In particular, it has been possible to develop a quantitative method for the evaluation of coexistence in nerve cell bodies. This method has been called the overlap method and allows an analysis cell by cell of the possible coexistence of two or more antigens.

Animals↗
PubMed1996

Near-field confocal optical spectroscopy (NCOS): subdiffraction optical resolution for biological systems.

Optical resolution is limited by diffraction. However, in near-field microscopes sample illumination is provided through a subwavelength aperture to increase optical resolution. In this study we have evaluated the usefulness of this technique for living biological systems and report two significant improvements in this form of microscopy to enhance optical resolution for biological studies. We report a unique feedback method, photon-density feedback, which is used to monitor the registration of a near-field illumination probe with living cell membranes. In this method, the fluorescence intensity of a uniformly distributed fluorochrome is monitored while the sample is moved in the z-axis towards the probe. Upon contact between the cell membrane and the near-field probe a maximum intensity is detected. A problem with near-field microscopy is that enhanced optical resolution is only achieved within the near-field of the illuminating aperture. Thick biological specimens also fluoresce in the far-field reducing optical resolution. To reduce this problem we incorporated a confocal pinhole together with the near-field probe to enhance the resolution of this form of near-field microscopy. Finally, we demonstrate that near-field confocal optical spectroscopy does not impair physiological properties of neurons, astrocytes or mast cells, indicating that this high-resolution optical methodology will permit a new approach to the study of molecular distribution and action within living specimens.

Aniline Compounds↗
PubMedDate not supplied

A new food guide for the Portuguese population: development and technical considerations.

The methodological approach used for the development of a new food guide for the Portuguese population is discussed. The new food guide, composed of seven groups, was achieved with the assistance of an expert panel, using existing international recommendations and nutrient composition tables. A range of recommended food portions was established for the groups of fats and oils; milk and dairy products; meat, fish, seafood, and eggs; pulses; potatoes, cereals, and cereal products; vegetables; and fruits. Posters and leaflets were produced and presented to the media with the support of health authorities and the scientific community. The dissemination materials were freely distributed to institutions and professionals responsible for health promotion.

Health Education↗
PubMed2004

Implementation of the European water framework directive from the Basque country (northern Spain): a methodological approach.

The European Water Framework Directive provides a challenge in the development of new and accurate methodologies. It addresses assessment of Ecological Quality Status within European rivers, lakes, groundwaters, estuaries and coasts. Although this directive is simple and flexible in its concept, it is necessary to develop an approach based upon scientific knowledge; however, at the same time it should be as simple as possible, in order to achieve both requirements and comparability of results throughout European waters. This contribution presents the first methodological approach to the problem, as used for estuaries and coasts of the Basque Country (northern Spain), in: selecting typologies and reference conditions; determining biological quality and ecological status; and identifying some problems in implementing the WFD. As such, the present paper could serve as the basis for a discussion document for other regions and countries, throughout Europe.

Ecology↗
PubMed2005

In-cell Western assay: a new approach to visualize tissue factor in human monocytes.

BACKGROUND: Tissue factor (TF) is an integral membrane protein essential for the initiation of the extrinsic pathway of hemostasis. A precise understanding of the TF regulation is still limited and dependent on the availability of methodological tools. Here, we describe a new approach for assessing TF amounts in human mononuclear cells (MNCs) by using the whole blood experimental conditions. AIM: In order to study TF antigen levels in human MNCs, we applied a quantitative immunostaining technique-- in-cell Western (ICW) assay using an Odyssey Infrared Imaging System. METHODS AND RESULTS: The ICW assay of TF in resting or lipopolysaccharide (LPS)-stimulated human MNCs was performed. Several sample preparation conditions were tested, namely the plating of MNCs prior to immunostaining, paraformaldehyde fixation, and an adequate cell number was used in the assay. By the use of recombinant human TF standards, it was possible, for the first time, to measure TF amounts in LPS-stimulated MNCs as 0.09 +/- 0.02 ng and 0.43 +/- 0.15 ng 10(-6) cells of surface and total TF, respectively. The concentrations of TF in resting MNCs, however, were below the detection limit. CONCLUSIONS: A novel TF ICW assay is a reproducible, time- and cost-saving method, which could become useful for studies in the fields of physiology and pathophysiology of human hemostasis.

Blotting, Western↗
PubMed2005

Ligand-metal ion binding to proteins: investigation by ESI mass spectrometry.

The objective of this chapter is to show the general mass spectrometry (MS)-based strategies that can be used to retrieve information regarding protein-metal and protein-ligand noncovalent complexes. Indeed, when using carefully controlled conditions in the atmospheric pressure-vacuum interface of the mass spectrometer, and when sample preparation is optimized, it is possible to preserve large specific multiprotein-metal-ligand noncovalent complexes during MS analysis. Examples describing the possibilities of electrospray ionization MS (ESI-MS) are shown. For instance, it can be used to probe cooperativity in the binding of a ligand or a metal to a protein or may constitute a new methodology for a more rational approach for drug discovery and for human genome annotation. Thanks to its ability to directly give information on stoichiometry or dynamics of the interactions formed in solution, MS offers new possibilities to tackle more and more various applications.

Animals↗
PubMed1976

Methodologic problems of common terminology, measurement, and classification. 11. Modifications and new approaches to taxonomy in long-term care: advantages and limitations of the ICD.

The primary advantage of an internationally accepted classification of diseases is that data from different countries and parts of the world can be compared and even pooled. Two basic conditions have to be fulfilled if the classification is to be used by a heterogeneous group of users and the data are to be compared: there must exist significant agreement on the content of categories, and the categories must be used in the agreed sense. A brief description is given of a WHO project that has attempted to satisfy these two conditions in the field of mental disorders. Additionally, taxonomy in long-term care requires that a classification should 1) be multiaxial and include certain nondisease as well as disease factors that affect treatment and outcome; 2) be a classification of individuals rather than of diseases and reflect the presence of multiple conditions and degrees of severity; 3) allow linkage of episodes of illness and care in the same individual; 4) be suitable for use by nonmedical personnel, who often play a decisive role in long-term care; and 5) be accompanied by glossaries giving operational terms suitable for reliability and validity tests.

Classification↗
PubMed2004

Defining a local arterial input function for perfusion MRI using independent component analysis.

Quantification of cerebral blood flow (CBF) using dynamic-susceptibility contrast MRI relies on the deconvolution of the arterial input function (AIF), which is commonly estimated from the signal changes in a major artery. However, it has been shown that the presence of bolus delay/dispersion between the artery and the tissue of interest can be a significant source of error. These effects could be minimized if a local AIF were used, although the measurement of a local AIF can be problematic. This work describes a new methodology to define a local AIF using independent component analysis (ICA). The methodology was tested on data from patients with various cerebrovascular abnormalities and compared to the conventional approach of using a global AIF. The new methodology produced higher CBF and shorter mean transit time values (compared to the global AIF case) in areas with distorted AIFs, suggesting that the effects of delay/dispersion are minimized. The minimization of these effects using the calculated local AIF should lead to a more accurate quantification of CBF, which can have important implications for diagnosis and management of patients with cerebral ischemia.

Blood Volume↗
PubMed1995

Estimating the occurrence of child maltreatment and risk-factor effects: benefits of a mixed-design strategy in epidemiologic research.

Despite the large volume of literature on child abuse and neglect generated over the past two decades, there has been relatively little comprehensive discussion of the limitations of different study designs for achieving major epidemiologic research goals. Although some improvements have been made in conventional research designs, there have been few efforts to develop new approaches. This article discusses the methodologic limitations of four observational study designs--ecologic, case-control, cross-sectional, and cohort--that dominate the child abuse and neglect literature; identifies key features of an "ideal" study of child maltreatment; and proposes a new mixed-design research strategy. The major advantage of the proposed strategy is that it greatly improves the ability to identify cases of child maltreatment from a well-defined population at risk representing diverse segments of the US population.

Child↗
PubMed2001

Elucidation of the function of two glycosyltransferase genes (lanGT1 and lanGT4) involved in landomycin biosynthesis and generation of new oligosaccharide antibiotics.

BACKGROUND: The genetic engineering of antibiotic-producing Streptomyces strains is an approach that became a successful methodology in developing new natural polyketide derivatives. Glycosyltransferases are important biosynthetic enzymes that link sugar moieties to aglycones, which often derive from polyketides. Biological activity is frequently generated along with this process. Here we report the use of glycosyltransferase genes isolated from the landomycin biosynthetic gene cluster to create hybrid landomycin/urdamycin oligosaccharide antibiotics. RESULTS: Production of several novel urdamycin derivatives by a mutant of Streptomyces fradiae Tü2717 has been achieved in a combinatorial biosynthetic approach using glycosyltransferase genes from the landomycin producer Streptomyces cyanogenus S136. For the generation of gene cassettes useful for combinatorial biosynthesis experiments new vectors named pMUNI, pMUNII and pMUNIII were constructed. These vectors facilitate the construction of gene combinations taking advantage of the compatible MunI and EcoRI restriction sites. CONCLUSIONS: The high-yielding production of novel oligosaccharide antibiotics using glycosyltransferase gene cassettes generated in a very convenient way proves that glycosyltransferases can be flexible towards the alcohol substrate. In addition, our results indicate that LanGT1 from S. cyanogenus S136 is a D-olivosyltransferase, whereas LanGT4 is a L-rhodinosyltransferase.

Aminoglycosides↗
PubMedDate not supplied

Clinical epidemiology of heart failure.

Heart failure (HF) is rapidly becoming one of the most prevalent cardiovascular disorders; the incidence of HF is expected to continue to increase in the years to come. The peculiarities of the syndrome require special approaches from the point of view of both clinical management and research methodology. As far as clinical management, new models based on a multidisciplinary approach and continuity of care should be implemented. The methodology of epidemiological research should take into account the complexity of the syndrome, the high frequency of comorbid conditions, the advanced age of typical patients, and the spreading of HF patients among different health care providers and specialists. In this paper, a general epidemiological view of HF is reported and studies of clinical epidemiology carried out in Italy in the area of HF are described. (c) 1999 by CHF, Inc.

Journal Article↗
PubMed1984

Dietary carcinogens and anti-carcinogens.

The scientific understanding of cancer and degenerative disease is being aided by new methodologies which are now used to approach the problem of environmental and occupational carcinogens and anticarcinogens. This paper reviews these powerful new tools and relates them to "natural" mutagens and carcinogens in food. It also discusses the use of oxygen radicals as a cause of degenerative disease associated with aging. Since no human diet can be totally free of carcinogens or mutagens, it is necessary to consider the risks of alternative courses of actions and to quantitate the magnitude of the risks through the "quantification" of these risks. Since carcinogens and anticarcinogens differ in their potency in animals over one million fold, the extrapolation of risks from rodents to humans is difficult but it is a first step. Despite better understanding of all of these risks, it is important to realize that the overall trend in life expectancy in the United States is continuing steadily to improve.

Aging↗