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PubMed1995

Database created from magnetic resonance images of a Sprague-Dawley rat, rhesus monkey, and pigmy goat.

To obtain a database of accurate anatomical images onto which dosimetry data of electromagnetic fields could be mapped, a healthy Sprague-Dawley rat, rhesus monkey, and pigmy goat were scanned using magnetic resonance imaging (MRI). Axial sections throughout the length of the animals were collected. Sections were 3 mm thick for the rat and 5 mm thick for the monkey and goat. Sagittal sections (2 mm thick) of the rat head were also scanned. Images were recorded on magnetic tape and transferred to computer disk for image enhancement and network distribution. Images are available in 16 bit Big Endian signed or 8 bit TIFF formats. This is the first database of contiguous MRI axial scans of rat, monkey, and goat available for distribution via magnetic tape (4 mm DDS) or Internet file transfer protocol. Digital transfer of the data was selected to preserve the integrity of each image, circumventing the need for the user to scan the images back into a digital format for use with their software. These images should be useful to physiologists, neuroscientists, veterinarians, anatomists, and teachers. Reconstructing these 2-dimensional images into 3-dimensional structures is an effective media for conveying spatial anatomical information in a quick and comprehensive manner.

Animals↗
PubMed1996

Big babies and infant leukemia: a role for insulin-like growth factor-1?

Several epidemiologic studies have demonstrated that high birthweight is associated with an increased risk of infant leukemia; however, the reason for this relationship is unclear. Biologic data demonstrate that birth weight is correlated positively with circulating levels of insulin-like growth factor-1 (IGF-1). IGF-1 is important in blood formation and regulation and has been shown to stimulate the growth of both myeloid and lymphoid cells in culture. Since infants who develop leukemia are likely to have had at least one transforming event occur in utero, we hypothesize that high levels of IGF-1 may both produce a larger baby and contribute to leukemogenesis.

Birth Weight↗
PubMed2006

Towards optimal endocrine therapy for hormone-sensitive breast cancer: initial versus sequential adjuvant aromatase inhibition.

Patients with hormone-receptor-positive early breast cancer have a significant risk of recurrence despite the use of adjuvant tamoxifen. The third-generation aromatase inhibitors letrozole, anastrozole, and exemestane offer promise as alternative or additional therapy to tamoxifen. As extended adjuvant therapy following completion of 5 years of tamoxifen, letrozole further decreased the risk of recurrence compared with placebo. Compared with tamoxifen, both letrozole and anastrozole significantly reduced the risk of recurrence when used as initial adjuvant therapy, and in the short term both were better tolerated than tamoxifen. Anastrozole and exemestane both reduced the risk of relapse when started after 2-3 years of tamoxifen compared with continued tamoxifen treatment; the results of letrozole in this setting are expected in 2008. These data establish adjuvant aromatase inhibitors as effective alternatives to tamoxifen. Only limited data are currently available to inform the choice between an aromatase inhibitor as either initial adjuvant therapy or sequentially after tamoxifen. Future results from the Breast International Group (BIG) 1-98 trial will further clarify strategies for the adjuvant use of aromatase inhibitors. Here, we critically review the evidence for adjuvant use of aromatase inhibitors. Comparison is made between initial aromatase inhibition, switching, and extended adjuvant strategies. Practical recommendations are given for the endocrine treatment of post-menopausal breast cancer.

Antineoplastic Agents, Hormonal↗
PubMedDate not supplied

Accumulation and partition of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) in the muscle and liver of fish.

The present study monitored fish from sites contaminated for many years, and the data reflected the results of actual, long-term environmental exposure. The sum concentrations and TEQs of PCDD/F in the muscle of common carp (Cyprinus carpio (linnaeus)) and big head (Aristichthys nobilis) from the different site of a heavily polluted lake in China are decreased with decrease of PCDD/F concentration in sediment and water. Concentration in fish can be highly variable, but the concentration is comparable in muscle between different species of fish if the concentrations are normalized by lipid content. PCDD/F accumulate in certain tissues with the highest proportions found in the liver of fish. The concentrations and TEQs in livers were also decreased with concentrations of sediments and water. The concentrations of PCDD/F in muscle are significantly correlated with those in liver. BCFs of 2,3,7,8-substituted PCDD/F calculated directly from water were consistent with that calculated indirectly from sediment. PCDD/F concentrations in sediment are much higher than that in water, therefore the measurement is much easier and the results are more accurate. Estimated BCFs for superhydrophobic chemicals derived from sediment may also serve as acceptable surrogates for "true" bioaccumulation potential.

Animals↗
PubMed1980

Conductimetric determination of thermodynamic pairing constants for symmetrical electrolytes.

Earlier theories of electrolytic conductance are reviewed; all of these, with the exception of the Arrhenius-Ostwald theory, are based on physical models. Their theory failed to describe the conductance of strong electrolytes because it did not include the effects (then unsuspected) of long-range forces on mobility. Thermodynamic derivations are independent of model; applied to the postulated equilibrium A(+) + B(-) right arrow over left arrow A(+)B(-) between free ions and nonconducting paired ions, the thermodynamic pairing constant K(a) equals a(p)/(a+/-)(2), and DeltaG, the difference in free energy between paired ions (activity = a(p)) and free ions (activity = a(+/-)), equals (-RT ln K(a)). Converting to the molarity scale, K(a) = (1000 rho/M)[1 - gamma)/cy(2)(y(+/-))(2)]. Here rho is the density of the solvent of molecular weight M, c is stoichiometric concentration of electrolyte (mol/liter), gamma is the fraction of solute present as unpaired ions, and y(+/-) is their activity coefficient. The corresponding conductance function Lambda = Lambda(c;Lambda(0),R, big up tri, openG)involves three parameters: Lambda(0), the limiting equivalent conductance; R, the sum of the radii of the cospheres of the ions; and DeltaG. Conductance data for cesium bromide and for lithium chloride in water/dioxane mixtures and for the alkali halides in water are analyzed to determine these parameters. Correlations between the values found for R and DeltaG and properties characteristic of salt and solvent are then discussed.

Journal Article↗
PubMed2006

Most spontaneous tumors in a mouse model of Li-Fraumeni syndrome do not have a mutator phenotype.

Mutations are the substrate of cancer. Yet, little is known about the degree and nature of mutations in tumors because measurement of mutation load in tumors and normal tissues was generally not possible until the advent of transgenic mouse mutation detection systems. Herein, we present the first analysis of mutation frequency and pattern in thymic tumors from a mouse model of Li-Fraumeni syndrome (p53+/- murine model) using the Big Blue assay with sequencing of all mutants. We also make the first characterization of mutation frequency and pattern in p53-deficient extra-thymic cancers. The data more than triple the literature on all non-mismatch repair deficient tumors for which mutations are identified by sequence analysis, allowing mutation frequency and pattern to be determined. Most tumors had a normal mutation frequency and a normal mutation pattern. Five tumors showed modest increases in mutation frequency (2.3-fold or less). Alterations in mutation patterns were uncommon, tumor-specific and not necessarily associated with increases in mutation frequency. Given the data from two spontaneous tumors (normal mutation frequency with an abnormal pattern in a p53-/- mouse and low mutation frequency in a p53+/+ control mouse), we hypothesize that tumors sometimes can carry a low mutation load. The study was not without certain caveats: mutation load could not be compared between tumor and normal tissue from the same animal; sample sizes for extra-thymic tumor types were small, and only point mutations and deletions, insertions and indels up to 2 kb were detected. However, the data clearly show key differences in tumors from p53+/- mice compared with mismatch repair deficient tumors; a lack of dramatic increase in mutation frequency and absence of a signature of mutation.

Animals↗
PubMed1984

Aspects of standardization as applied to the assessment of drug-event associations.

Individual case reports about suspected adverse drug reactions are an important source of drug safety data. Their evaluation involves, among other things, the assessment of causality. Usually it is done by expert medical evaluators according to their knowledge and experience. Subjectivity plays a big role as demonstrated by comparison of assessments of the same cases by several evaluators or by the same evaluator at a later date. In recent years, methods of causality assessment based on algorithms were introduced. In these formal approaches, items of information contribute to the assessment in a predetermined and standardized way with a logic that allows operational application. Results obtained with different methods may differ because items of information considered may not be the same and/or strength of evidence attached to them vary from one method to another. The main advantages of standardized assessment are: clear identification of items of information involved, improved communication, reproducibility of results, and the checklist function. Various implications of standardized assessment are discussed and ways to improve their performance outlined.

Drug-Related Side Effects and Adverse Reactions↗
PubMed2000

A review of maternal deaths in South Africa during 1998. National Committee on Confidential Enquiries into Maternal Deaths.

OBJECTIVE: To document the prevalence and causes of maternal mortality and to identify avoidable factors, missed opportunities and substandard care related to these deaths. METHOD: Maternal deaths are notifiable; when a maternal death occurs a maternal death notification form is filled in and sent to the provincial Maternal, Child and Women's Health (MCWH) units. Provincial assessors assess the death and submit a report. This report is forwarded to the National Committee on Confidential Enquiries into Maternal Deaths (NCCEMD), where the data are collated and the prevalence, pattern of disease, avoidable factors, missed opportunities and substandard care pertaining to maternal deaths are described. RESULTS: Data were collected on the maternal deaths occurring during 1998 in South Africa. Collection of data on maternal deaths was incomplete and a maternal mortality ratio could not be calculated. However, a clear pattern of disease and problems in patient care emerged. The 'big five' causes of death were complications of hypertensive conditions in pregnancy, AIDS, obstetric haemorrhage, pregnancy-related sepsis and pre-existing medical conditions. Women aged 30 years and older were at greater risk of dying than younger women. Women in their first pregnancy or who had had 5 or more pregnancies were also at greater risk. Obstetric haemorrhage was the most common cause of death at level 1 hospitals, AIDS at level 2 hospitals and hypertensive diseases at level 3 hospitals. The vast majority of anaesthetic-related deaths occurred at level 1 hospitals. Non-attendance and delayed attendance at the health institutions were the most common patient-orientated problems. Poor transport facilities and lack of intensive care facilities were the major administrative problems. Problems in the care of women occurred in more than half the cases of maternal death, the majority at the primary level of care. Poor initial assessment and diagnosis of cases, especially at secondary level of care, failure to follow standard protocols at primary and secondary levels, and poor monitoring of patients at all levels of care were the common health worker-related problems. CONCLUSION: Ten key recommendations based on this information have been made by the NCCEMD; if implemented these will result in a reduction of maternal deaths.

Acquired Immunodeficiency Syndrome↗
PubMed2004

Potential applications of smart clothing solutions in health care and personal protection.

The rapid development in the fields of sensor and telecommunication technologies has created completely new possibilities also for the textile and clothing field. New smart textile and clothing systems can be developed by integrating sensors in the textile constructions. Application fields for these added-value products are e.g. protective clothing for extreme environments, garments for the health care sector, technical textiles, sport and leisure wear. Some products have already been introduced on the markets, but generally it can be stated that the development is only in its starting phase, and the expectations for the future are big. Many different aspects have to be considered in the development of the wearable technology products for the health care sector: medical problems and their diagnosis, sensor choice, data processing and telecommunication solutions, clothing requirements. A functional product can be achieved only if all aspects work together, and therefore experts from all fields should participate in the RTD projects. In the EC-funded project DE3002 Easytex clothing and textiles for disabled and elderly people were investigated. Some recommendations concerning durability, appearance, comfort, service and safety of products for different special user groups were defined, based on user questionnaires and seminars, general textile and clothing requirements and on laboratory test series."Clothing Area Network--Clan" is a research project aiming to develop a technical concept and technology needed in enabling both wired and wireless data and power transfer between different intelligent modules (user interfaces, sensors, CPU's, batteries etc.) integrated into a smart clothing system. Fire-fighters clothing system is chosen as the development platform, being a very challenging application from which the developed technology can be transferred to other protective clothing systems.

Absorbent Pads↗
PubMed1988

Birth defects in the Seveso area after TCDD contamination.

A study on the frequency of birth defects was conducted in the area around Seveso, Italy, which was contaminated by 2,3,7,8-tetrachlorodibenzo-p-dioxin in July 1976; this has been the largest population ever exposed to dioxin. From Jan 1, 1977, to Dec 31, 1982, a total of 15,291 births (still and live) were examined, and malformations were reported to an ad hoc birth defects registry. In the most highly contaminated area, 26 births were observed. None of these infants had any major structural defect. Two infants had mild defects. The frequencies of major defects detected in the areas of low or very low contamination were 29.9/1000 and 22.1/1000, respectively. A frequency of 27.7/1000 was registered in the control area. Relative risks were calculated for specific categories of birth defects and for grouped malformations. Although the data collected failed to demonstrate any increased risk of birth defects associated with 2,3,7,8-tetrachlorodibenzo-p-dioxin, the number of exposed pregnancies was not big enough to show a low and specific teratogenic risk increase.

Accidents, Occupational↗
PubMed2006

Minimally-compressive, three- and four-dimensional ultrasound imaging of the clitoris: a feasibility study.

There has been no objective means for imaging the three-dimensional (3D) morphology of the clitoris-a poorly understood, complex structure. A Live 3D ultrasound system with a matrix-array transducer was used for data acquisition from eight women. The transducer was positioned in front of and about 3 cm away from the clitoris, with a gel pad or water pad being placed in between. The pads allowed the delicate structures to be imaged without noticeable deformation. Quality images could be obtained with use of a water pad in all patients. The imaging volume was big enough to cover the clitoral glans and body simultaneously, allowing real-time 3D visualisation. To cover the entire clitoris, the probe was moved from one side of the crus to the other, or a four subvolume scan was performed. 3D clitoral anatomy was depicted from 71% of 51 water pad data-sets. The study demonstrates the feasibility of obtaining 3D clitoral ultrasound images. This will improve scientific and clinical understanding of the clitoral role in sexual activity. The minimally-compressive scanning offers an opportunity to visualise dynamic 3D (4D) morphology of other deformable body parts.

Adult↗
PubMed1992

Solution conformation of human big endothelin-1.

The solution conformation of human big endothelin-1, a 38-residue peptide which serves as the putative precursor to the potent vasoconstrictor endothelin-1 has been examined by 1H NMR. NOEs were utilized as distance restraints in the distance geometry program DSPACE to generate initial structures. Further refinement of these structures was accomplished through molecular mechanics/molecular dynamics in an iterative process involving the incorporation of stereospecific assignments of prochiral centers and the use of back-calculation of NOESY spectra. A family of structures consisting of a type II beta-turn for residues 5-8 and an alpha-helix extending from residues 9-16 constitute a well-defined region, as reflected by the atomic root-mean-square (RMS) difference of 1.56 A about the mean coordinate positions of the backbone atoms (N, C, C alpha and O). This core region (residues 1-15) is very similar to the core residues of endothelin-1 (Donlan, M. et al. (1991) J. Cell. Biochemistry, S15G, 85). While the evidence from NOESY and coupling constant data suggests that the C-terminal region, residues 17-34, is not a mixture of randomly distributed chain conformations, it is also not consistent with a single chain conformation. Under the conditions studied, residues 17-38 in human big endothelin-1 in water at pH 3.0 between 20-30 degrees C appear to be represented by a series of conformers in dynamic equilibrium.

Amino Acid Sequence↗
PubMed1998

Value of cardiopulmonary exercise testing and big endothelin plasma levels to predict short-term prognosis of patients with chronic heart failure.

OBJECTIVES: We tested the hypothesis that, in patients with stable heart failure, measuring big endothelin-1 (ET-1) plasma level at rest predicts short-term prognosis better than peak oxygen consumption (VO2max) at exercise. BACKGROUND: Cardiopulmonary exercise testing and evaluation of neurohumoral plasma factors are established tools to estimate survival in patients with heart failure. No data, however, exist comparing the prognostic value of both marker categories simultaneously. METHODS: Two hundred twenty-six heart failure patients were studied in regard to a combined end point of death and prioritization for urgent cardiac transplantation within 1 year follow-up. RESULTS: During the study period 149 patients were without cardiac events (group A), 69 patients died or were urgently transplanted (group B) and 8 patients were alive after a nonurgent heart transplant operation. Norepinephrine (p < 0.0001), atrial natriuretic peptide (p < 0.001), big endothelin plasma levels (p < 0.0001 as well as workload, VO2max and achieved percentage of predicted peak oxygen consumption (pVO2max) (all p < 0.0001) differed significantly between groups A and B. In multivariate stepwise regression analysis, however, only big ET-1 plasma concentration (chi2=74.4, p < 0.0001), New York Heart Association function class (chi2=33.9, p < 0.0001), maximal workload (chi2=7.2, p < 0.01, and plasma atrial natriuretic peptide (ANP) concentration (chi2=4.6, p < 0.05) were independently related to outcome. Peak oxygen consumption or pVO2max did not reach statistical significance in this model. Event-free survival rates were significantly lower in patients with a big ET-1 level of 4.3 fmol/ml or more than with lower big ET-1 levels (p < 0.0001). CONCLUSION: We conclude that in patients with chronic heart failure who are stable on oral therapy measuring big ET-1 and ANP plasma levels may be a valuable noninvasive adjunct to improve the prognostic accuracy of detecting high risk patients compared with exercise testing alone.

Adult↗
PubMed1990

Three-wheeled vehicle injuries in children.

Injuries associated with nonmotorized three-wheeled vehicles were prospectively evaluated through a standard questionnaire during the summer months at the emergency department of the Children's Hospital of Philadelphia, Pa. Forty-four children, including 32 boys, with a mean age of 3.77 years, reported such injuries. Most fell (36.4%), but a second vehicle was often involved. Most children (33 of 44) were on low-slung Big Wheels. Head, neck, and dental injuries accounted for the majority. Most injuries were not serious. Two patients were admitted; both had fractures, one of them had a concussion. Data from the US Consumer Product Safety Commission corroborate the epidemiology of these injuries. Recommendations of safety precautions with non-motorized three-wheeled vehicles are reviewed.

Accidents↗
PubMed2006

The usefulness of artificial neural networks in the evaluation of pulmonary efficiency and antioxidant capacity of welders.

OBJECTIVE: The aim of the study was to determine if artificial neural networks (ANNs) may be useful to analyse a complex and large set of data derived from smoking welders for the purpose of finding relationships between parameters describing respiratory system efficiency and antioxidant defence. METHODS: A group of 94 welders employed in a big metallurgic enterprise in Krakow, Poland (men only, aged 29-57 years, all active smokers) occupationally exposed to O(3) and NO(x), were the subjects of this study. They underwent biochemical measurements including total antioxidant status (TAS) and the anti-oxidative defence enzymes superoxide dismutase (SOD) and catalase (CT); biominerals: Fe, Cu, Zn, Mg in blood serum and in hair; the concentrations of albumin, bilirubin, uric acid in blood. The determination of respiratory efficiency was based on a "flow-volume" curve and spirometry. The dependant variables for ANNs were: TAS, SOD, CT. Thirty-one subjects with normal values of all spirometric parameters were selected for the final analysis. RESULTS: Statistically valid relationship between TAS and albumin, Zn and Cu in blood and the two pulmonary parameters forced expiratory volume after 1s (FEV(1)) and middle expiratory flow of 25-75% of vital capacity (MEF(25/75)) were found. Zn concentration almost linearly influenced TAS. For Cu a sigmoid curve was obtained. For albumin concentration as well as for FEV(1) a two-stage curve was observed. CONCLUSIONS: ANNs are useful for the reduction of dimensionality and are suited to analyse a complex and relatively large set of parameters when it is unknown which of these are related. ANNs were useful for finding the relationship between the antioxidant defence and the respiratory system capacity in welders who smoke.

Adult↗
PubMed2002

The evolution of monogenean diversity.

The Monogenea are an ideal group for investigations of the processes behind their past diversification and their present diversity for at least three reasons: they are diverse both in terms of morphology and numbers, they are generally host specific, and their phylogeny is well resolved, at least to the family level. The present investigation takes a broad look at monogenean diversity in order to try to determine whether the diversification of monogeneans is driven by some ecological features of the parasites themselves, or by extrinsic factors associated with their hosts. First, our current knowledge of monogenean diversity appears good enough to warrant investigation into its evolution. The body size of new species correlates negatively with their year of description both generally and within given families, i.e. it decreases over time in a way that suggests that only some of the smallest species are left to be discovered. Second, the occurrence of congeneric monogenean species on the same host species is not associated with host body size, once phylogenetic influences are controlled. This analysis suggests that host size is not one of the factors promoting local diversification of monogenean taxa. Third, the species richness of the different monogenean families does not correlate with the average body size of their members. Thus, this basic parasite life-history trait is not a determinant of diversification rates. Combined, the results of these separate analyses provide preliminary answers to some of the big questions concerning the diversification of monogeneans, but leave many other questions unanswered. The phylogenetic analytical framework adopted here should allow these questions to be tackled once the necessary data become available.

Animals↗