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At least 451 records · Page 25Linked to original sources
PubMed2000

Refined and whole grain cereals and the risk of oral, oesophageal and laryngeal cancer.

OBJECTIVE: To investigate the possible differential role of refined and whole grain cereals on the risk of upper digestive and respiratory tract neoplasms. DESIGN: Hospital-based case-control study. SETTING: University Hospital of Lausanne, Switzerland. SUBJECTS: A total of 156 incident cases of cancers of the oral cavity and pharynx, 101 of the oesophagus, 40 of the larynx, and 349 control subjects admitted for a wide spectrum of acute non-neoplastic conditions. INTERVENTION: Trained interviewers collected information using a structured and validated questionnaire. Odds ratios (OR) of various cancers for a tertile increment of intake of refined and whole grains were estimated using unconditional multiple logistic regression. RESULTS: Refined grains were directly related to the risk of cancer of the oral cavity and pharynx (OR=1.9 for the highest tertile), oesophagus (OR=3.7) and larynx (OR=4.0). In contrast, whole grain cereals were protective, with OR of 0.6 for oral cavity and pharynx, 0.3 for oesophagus, and 0.7 for larynx. For the three sites combined, the OR for the highest tertile was 5.7 for refined grains and 0.5 for wholegrains. The trends in risk for refined grains were significant for all sites and their combination, and for wholegrain for oesophageal cancer and all sites. CONCLUSIONS: Even if inference on causality and the biological interpretation remain open to discussion, the present data indicate and further quantify that refined cereals are an unfavourable, but whole grain ones a favourable indicator of the risk of upper aerodigestive and respiratory tract neoplasms.

Adult↗
PubMed2000

Assessment of psychiatric patients' competency to give informed consent: legal safeguard of civil right to autonomous decision-making.

Amendment of the Mental Health and Welfare Law in Japan will limit admission for medical care and protection only for those individuals who are incapable of giving consent to admission. This is a first in the history of the Japanese mental health legislation. By reviewing the law and psychiatric literature, it is argued that: (i) informed consent is a legal transaction that embodies the idea of an individual's right to autonomous decision-making in medical settings; (ii) health professionals have a duty to protect those individuals who cannot decide medical matters because of lack of capacity to do so; (iii) some patients are marginally incompetent so assessment of their competency is essential in protecting patients' civil rights; (iv) in order for a competency assessment to be reliable (and hence fair) the method should be psychometrically sound; (v) at the same time, in order for a competency assessment to be valid, the structure of a competency assessment should match the patient's psychological, cultural, and social background; and (vi) because informed consent is a process rather than a cross-sectional event, a competency assessment should be performed in everyday practice. The use of a brief and semistructured interview to assess patients' competency to give informed consent may meet all of the requirements described.

Decision Making↗
PubMed2001

Lymph nodes in the human female breast: a review of their detection and significance.

Our experience led us to test the hypothesis that lymph nodes are not uncommon within the substance of the human female breast mound. The following specimen types and sources were used to survey the presence of intramammary lymph nodes in the human female breast mound: (1) cadaver breasts; (2) community hospital breast specimens; and (3) university and VA hospital specimens. We found true lymph nodes within and associated with breast specific tissue (ie, tissue that includes duct and gland structures), thereby validating the hypothesis posed. We discuss the significance of these findings in terms of our dominant patient care paradigm (the Triple Test-physical examination, imaging, and fine-needle aspiration [FNA]) and the choice of patient care management options. We conclude the following: lymph nodes occur in any quadrant of the breast mound; recognizing the possibility of intramammary lymph nodes is important when choosing between patient management options; intramammary lymph nodes can be sampled by FNA; intramammary lymph nodes can contain various disease processes; and in the Oregon Health Sciences University Multidisciplinary Breast Clinic, these intramammary lymph nodes are commonly identified by imaging methods and are more likely to be sampled by FNA than either by core or excisional biopsy.

Adult↗
PubMed2001

Clinical outcomes that fetal surgery for myelomeningocele needs to achieve.

INTRODUCTION: The development of techniques to close open neural tube malformations prior to birth has generated great interest and hope for fetal interventions and their outcomes. To plan a randomized trial, as is being discussed at three centres in the United States, the determination of what constitutes a clinically significant improvement in outcome is critical. To date, preliminary observations from two centres suggest that improvements may occur, not in spinal cord function as originally postulated, but in the extent of the hindbrain hernia and the frequency that shunting is required to control hydrocephalus. PURPOSE: The determination of what outcome would constitute an important and clinically significant difference in outcome to be achieved by fetal intervention for myelomeningocele. METHOD: Parents of patients and patients treated in our myelomeningocele clinic were surveyed using a structured and validated tool. From the perspective of a recommendation to a close friend or family member, the interviewees were asked to quantify on a scale from 0 to 100 the chance of specific outcomes (need for a shunt, need for a wheelchair, change of urinary incontinence) that a fetal operation would need to predictably achieve. RESULTS: Responses were obtained from 77 patients/families. The fifty percentile response in each study dimension was as follows: the chance of needing a shunt was 12 % (range 0 - 50 %), the chance of needing a wheelchair was 8 % and the chance of being incontinent was 5 % (range 0 - 25 %). CONCLUSIONS: Fetal interventions will have to achieve significant improvements in the control of hydrocephalus, mobilization and continence over postnatal treatment to be justified.

Adult↗
PubMed2003

[Intraoperative histological sections in obstetric brachial plexus lesions--comparison of macroscopic appearance, HE staining and toluidine blue staining].

In brachial plexus lesions and their revision, evaluation of nerve stumps is very important for the reconstructive strategy. We intraoperatively perform cryostat sections, Haematoxilin-Eosin (HE) stained, and compare the clinical appearance of the nerves to the microscopic results. Toluidine blue staining is later used to validate the structural details. Intraneural fibrosis can be traced safely with both staining methods, in root avulsions a histology is helpful, too. For more proximal, intraforaminal lesions semithin section stained with toluidine-blue are less informative than are HE-stained cryostat sections. In these lesions the clinical control by electrical stimulation and evoked potentials is superior.

Adult↗
PubMed2001

A membrane-distal segment of the integrin alpha IIb cytoplasmic domain regulates integrin activation.

Previous evidence suggests that interactions between integrin cytoplasmic domains regulate integrin activation. We have constructed and validated recombinant structural mimics of the heterodimeric alpha(IIb)beta(3) cytoplasmic domain. The mimics elicited polyclonal antibodies that recognize a combinatorial epitope(s) formed in mixtures of the alpha(IIb) and beta(3) cytoplasmic domains but not present in either isolated tail. This epitope(s) is present within intact alpha(IIb)beta(3), indicating that interaction between the tails can occur in the native integrin. Furthermore, the combinatorial epitope(s) is also formed by introducing the activation-blocking beta(3)(Y747A) mutation into the beta(3) tail. A membrane-distal heptapeptide sequence in the alpha(IIb) tail ((997)RPPLEED) is responsible for this effect on beta(3). Membrane-permeant palmitoylated peptides, containing this alpha(IIb) sequence, specifically blocked alpha(IIb)beta(3) activation in platelets. Thus, this region of the alpha(IIb) tail causes the beta(3) tail to resemble that of beta(3)(Y747A) and suppresses activation of the integrin.

Amino Acid Sequence↗
PubMed2000

Structure of an 11-mer DNA duplex containing the carbocyclic nucleotide analog: 2'-deoxyaristeromycin.

2'-deoxyaristeromycin (dAr) is a nucleoside analogue that is resistant to the action of DNA glycosylases. High-resolution NMR spectroscopy and molecular dynamics simulations were used to determine the three-dimensional structure of an 11-mer DNA containing a single dAr.T base pair at its center. Analysis of the spectra revealed the existence of a right-handed duplex in solution, stabilized by Watson-Crick hydrogen bonding and base-stacking interactions. The carbocyclic sugar adopted a C1'-exo conformation and sugars of the 3'-flanking base pair had puckers in the O4'-endo range. The dAr.T base pair was mildly propeller twisted, and the dAr analogue showed a positive roll with the 3'-flanking base. Our findings indicate that the observed resistance of dAr-containing oligodeoxynucleotides to the catalytic action of DNA glycosylases relates to its electronic properties rather than structure, and validate the use of dAr and related carbocyclic nucleoside analogues for biological and structure/function relationship studies.

Computer Simulation↗
PubMed1982

Sequences of three molluscan 5 S ribosomal RNAs confirm the validity of a dynamic secondary structure model.

The collection of known 5 S rRNA primary structures is enriched with the sequences from three mollusca, the snails Helix pomatia and Arion rufus, and the mussel Mytilus edulis. The three sequences can be fitted in a five-helix secondary structure model previously shown (De Wachter et al. (1982) Biochimie 64, 311-329) to apply to all 5 S RNAs regardless of their origin. One of the helices in this model can undergo a bulge-internal loop transition. Within the metazoan kingdom, the dimensions of each helix and loop are rigidly conserved, except for one helix which can comprise either 6 or 7 base pairs.

Animals↗
PubMed1997

Protein engineering tests of a homology model of Plasmodium falciparum lactate dehydrogenase.

This paper describes the testing of a homology model of Plasmodium falciparum lactate dehydrogenase (pfLDH) by protein engineering. The model had been validated in structural terms. It suggests explanations of the unusual properties of pfLDH (compared with all other LDHs). These unusual features are a lack of substrate inhibition, high activity with the synthetic coenzyme 3-acetylpyridine adenine dinucleotide (APAD+) and changes in residues at previously conserved positions. pfLDH shows several amino acid insertions and deletions in an alignment with protein sequences from all other known LDHs. The most notable is a five amino acid insertion into the active-site loop. In addition, a conserved serine at position 163 is replaced by leucine. The results showed that when the unique pfLDH structural features were engineered into Bacillus stearothermophilus lactate dehydrogenase, the thermophilic enzyme acquired the properties previously uniquely associated with the malarial enzyme. We conclude that the homology model of the malarial enzyme is adequate for the prediction of successful redesigns and, in the regions tested, is accurate.

Amino Acid Sequence↗
PubMed1999

Effects of an organized critical care service on outcomes and resource utilization: a cohort study.

OBJECTIVE: To determine whether the presence of an on-site, organized, supervised critical service improves care and decreases resource utilization. DESIGN: The study compared two patient cohorts admitted to a surgical intensive care unit during the same period of time. The study cohort was cared for by an on-site critical care team supervised by an intensivist. The control cohort was cared for by a team with patient care responsibilities in multiple sites supervised by a general surgeon. The main outcome measures were duration of stay, resource utilization, and complication rate. SETTING: Study patients were general surgical patients in an academic medical center. RESULTS: Despite having higher Acute Physiology and Chronic Health Evaluation II scores, patients cared for by the critical care service spent less time in the surgical intensive care unit, used fewer resources, had fewer complications and had lower total hospital charges. The difference between the two cohorts was most evident in patients with the worst APACHE II score. CONCLUSIONS: Critical care interventions are expensive and have a narrow safety margin. It is essential to develop structured and validated approaches to study the delivery of this resource. In this study, the critical care service model performed favorably both in terms of quality and cost.

APACHE↗
PubMed1999

Ten-year follow-up of adolescent-onset anorexia nervosa: personality disorders.

OBJECTIVE: To study the development of personality disorders, especially those involving obsessions, compulsions, and social interaction problems, in a representative group of anorexia nervosa (AN) cases. METHOD: The prevalence of personality disorders, obsessive-compulsive disorder, and autism spectrum disorders at mean age 24 years (10 years after reported onset) was examined in 51 adolescent-onset AN cases recruited after community screening and 51 comparison cases matched for age, sex, and school. All 102 cases had originally been examined at age 16 years and followed up at 21 years. At 24 years, structured and validated psychiatric diagnostic interviews were performed by a psychiatrist who was blind to original diagnosis. The majority of AN cases (94%) were weight-restored. RESULTS: Personality disorders, particularly cluster C, and autism spectrum disorders were overrepresented in the AN group. Obsessive-compulsive personality disorder and/or autism spectrum disorder was diagnosed in a subgroup of AN cases in all 3 studies. This subgroup had a very poor psychosocial outcome. CONCLUSIONS: Persistent problems with obsessions, compulsions, and social interaction characterized a substantial minority of weight-restored AN cases at 10-year follow-up. These problems appear to be constitutional rather than a result of AN, and they may warrant a different treatment approach.

Adolescent↗
PubMedDate not supplied

Development and testing of the caregiver reciprocity scale.

The purpose of this study was to develop and validate the dimensions of caregiver reciprocity. Social exchange and equity theory served as a conceptual framework for examining recprocal intergenerational exchanges of assistance and support. In the first phase of the study, 12 caregivers of elderly parents, including in-laws, were interviewed to provide narrative data from which items were developed. Content validity was judged by two separate panels of experts. The revised CRS was tested with 303 adult children for reliability and validity, including internal consistency, test-retest reliability, exploratory factor analysis, and convergent and discriminant validity testing using structural equation modeling. Support for construct validity was demonstrated for four factors: Warmth and Regard, Intrinsic Rewards of Giving, Love and Affection, and Balance within Family Caregiving.

Aged↗
PubMed1995

Measuring the functional status of patients with low back pain. Assessment of the quality of four disease-specific questionnaires.

STUDY DESIGN: This study was a literature review of the quality of four disease-specific functional status questionnaires for patients with low back pain: Oswestry; Million; Roland; and Waddell disability questionnaire. OBJECTIVES: The questionnaires were evaluated in terms of general description, scale structure, reliability, validity, responsiveness, and clinical research applications. SUMMARY OF BACKGROUND DATA: Functional status is an outcome of great interest for clinical trials of low back pain. METHODS: A computer-aided search was conducted of articles published between 1981 and 1993 and references given in selected relevant publications. Articles were selected if at least one of the four functional status questionnaires was used or if the authors gave relevant information about the methodology of these questionnaires. RESULTS: There was not enough information available about the criteria of item selection used for the development of the questionnaires. The test-retest reproducibility of the questionnaires seemed satisfactory. The Oswestry and Roland disability questionnaires have been used and evaluated more frequently than the Million and Waddell. Therefore, we can be more certain about the validity and responsiveness of the former pair of questionnaires. CONCLUSION: In the absence of a gold standard, direct comparisons of evaluative functional status questionnaires in a single patient group are needed. Through direct comparisons, comparative validity and responsiveness can be assessed. Functional status measures are not currently used in many settings in which they would be valuable. It is important to encourage their wider use in clinical trials. Additional research is needed to compare and improve the existing questionnaires.

Activities of Daily Living↗
PubMed2001

Neural systems underlying episodic memory: insights from animal research.

Two strategies used to uncover neural systems for episodic-like memory in animals are discussed: (i) an attribute of episodic memory (what? when? where?) is examined in order to reveal the neuronal interactions supporting that component of memory; and (ii) the connections of a structure thought to be central to episodic memory in humans are studied at a level of detail not feasible in humans. By focusing on spatial memory (where?) and the hippocampus, it has proved possible to bring the strategies together. A review of lesion, disconnection and immediate early-gene studies in animals reveals the importance of interactions between the hippocampus and specific nuclei in the diencephalon (most notably the anterior thalamic nuclei) for spatial memory. Other parts of this extended hippocampal system include the mammillary bodies and the posterior cingulate (retrosplenial) cortex. Furthermore, by combining lesion and immediate early-gene studies it is possible to show how the loss of one component structure or tract can influence the remaining regions in this group of structures. The validity of this convergent approach is supported by new findings showing that the same set of regions is implicated in anterograde amnesia in humans.

Amnesia↗
PubMed2002

Scaling hypothesis leading to generalized extended self-similarity in turbulence.

A scaling hypothesis leading to generalized extended self-similarity (GESS) for velocity structure functions, valid for intermediate scales in isotropic, homogeneous turbulence, is proposed. By introducing an effective scale ŕ, monotonically depending on the physical scale r, with the use of the large deviation theory, the asymptotic forms of the probability densities for the velocity differences u(r) and for the coarse-grained energy-dissipation rate fluctuations epsilon(r), compatible with this GESS, are proposed. The probability density for epsilon(r) is shown to have the form P(r)(epsilon) approximately equal to epsilon(-1)(ŕ/L)(S(ŕ)[z(ŕ)](epsilon))) with z(ŕ)(epsilon)=ln(epsilon/epsilon(L))/ln(L/ŕ), where L and epsilon(L) are the stirring scale and the coarse-grained energy-dissipation rate over the scale L. The concave function S(ŕ)(z), the spectrum, plays the central role of the present approach. Comparing the results with numerical and experimental data, we explicitly obtain the fluctuation spectra S(ŕ)(z).

Journal Article↗
PubMed2003

Oscillating Coulomb chain in a storage ring.

The dynamic behavior of a bunched one-dimensional crystalline beam is studied theoretically. It is shown that, owing to the existence of momentum dispersion, a Coulomb chain traveling in a storage ring performs a complex periodic oscillation whenever it is exposed to a longitudinal radio-frequency force. The equations of motion are derived to predict the oscillation pattern in an arbitrary lattice structure. The validity of the present theory is confirmed through multiparticle simulations. Various features of an oscillating string beam, such as the lattice-parameter dependence of the orbit, the stability, and critical line density, etc., are also discussed.

Journal Article↗
PubMed2000

Nonparametric rank-based methods for group sequential monitoring of paired censored survival data.

This research gives methods for nonparametric sequential monitoring of paired censored survival data in the two-sample problem using paired weighted log-rank statistics with adjustments for dependence in survival and censoring outcomes. The joint asymptotic closed-form distribution of these sequentially monitored statistics has a dependent increments structure. Simulations validating operating characteristics of the proposed methods highlight power and size consequences of ignoring even mildly correlated data. A motivating example is presented via the Early Treatment Diabetic Retinopathy Study.

Biometry↗
PubMed1995

The prevention of mechanical birth trauma by means of computer aided simulation of delivery by means of nuclear magnetic resonance imaging and finite element analysis.

Anatomic disproportion gains an increasing interest in obstetrics. Imaging procedures (radiologic pelvimetry, computed or magnetic resonance imaging (MRI) fail to reflect the dynamics of delivery including deformations of the birth channel as well as of fetal structures. To validate findings of imaging procedures in this respect a method has been developed to perform a dynamic, biomechanical postprocessing of the static informations obtained from MRI. Using an especially developed software MRI pixel matrices of maternal pelvis and fetal head were color-codef1p4d--according to the principle of same density--line data were created. After sectional attribution of the resulting polygones a three-dimensional mesh of so called Finite elements (FE) was created, which then can be used for deformation analysis. Fetal head was then moved through the birth channel by means of computed simulation. This allows not only ongoing deformations to be visualized but also resulting forces to be calculated for at any time of the delivery process for any point of the anatomical model. Performing these simulations assuming various anatomic and physiologic conditions an obstetrical-biomechanical data basis could be obtained, that was implemented in a PC-based expert system. This allows interpretation of pelvimetric data with regard to birth dynamics.

Biomechanical Phenomena↗