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At least 685 records · Page 38Linked to original sources
PubMed1998

Traumatic lumbar pseudomeningocele occurring with spina bifida occulta.

Pseudomeningocele in the lumbar spine due to spinal fractures or surgical procedures are well-recognized complications. We treated a 24-year-old man who fell from a horse, landing on his buttocks, and developed headaches, back pain, and a large lumbar subcutaneous fluid collection. Plain radiographs and magnetic resonance (MR) imaging revealed a midline defect in the sacral lamina and a large fluid collection in the subcutaneous space consistent with cerebrospinal fluid (CSF). He was treated conservatively, his symptoms resolved, and follow-up MR imaging showed resolution of the CSF accumulation. To our knowledge, there have been no cases of traumatic pseudomeningocele related to spina bifida occulta reported in the literature. The authors postulate that congenital defects in the neural arch contribute to the occurrence of this entity, and nonsurgical treatment should be the initial course.

Adult↗
PubMed1998

[Man and the diversity of his genome. An extraordinary phase in the history of population genetics].

Population genetics is almost eighty years old, but benefited only very recently from the advantages of direct DNA analysis. Nevertheless, much knowledge had already accumulated and was completely confirmed by the study of DNA markers. Major benefits of the latter came with microsatellites. It allowed to discover an error made with classical markers but even more seriously with RFLPs, because of the practically involuntary sampling of individuals almost exclusively of European origin for the detection of polymorphisms. Among other evolutionary application of microsatellites, the most attractive is their very recent use for dating population separations during the recent migration out of Africa of modern humans. They confirm the theory that this expansion was quite recent. Single nucleotide substitutions are the major material of evolution, and so far markers of this kind were rare. A new method, DHPLC, is excellent for their detection and testing. In humans it has been applied almost exclusively to the Y chromosome, and in a year it has given a completely new picture of Y chromosome genetics. Some applications of statistical methods to genetic geography of classical markers and ADN markers will show the power of the geographical approach, and therefore the need of a wide collection of population samples, as will be made possible by the HGDP (Human Genome Diversity Project).

Africa↗
PubMed1995

Chronic accumulation of cadmium in the edible tissues of Oreochromis aureus (Steindachner): modification by mercury and lead.

The influence of mercury and lead on cadmium accumulation was investigated by exposing the fish Oreochromis aureus, or Blue Tilapia, to two heavy metals simultaneously. The chronic accumulation profile of cadmium in the liver, brain, gill filaments, intestine, caudal muscle, spleen, trunk kidney, and gonads was determined for exposure to cadmium alone and with lead or mercury. O. aureus was exposed to cadmium alone at 0.05 and 0.10 mg/L, and mixtures of 0.05 mg/L cadmium with 0.05 mg/L mercury or lead (0.05 and 0.50 mg/L). Little research has previously been carried out on the long-term interaction between these heavy metals and their effects on tissue accumulation of heavy metals. In a food fish such as O. aureus, a knowledge of toxic metal accumulation patterns is of great importance. The highest levels of cadmium were consistently accumulated by the kidney, and the presence of other mercury or lead did not change this trend. The spleen, intestine, and liver also accumulated high levels of cadmium, while the caudal muscle and brain accumulated the lowest levels of cadmium. Separating the viscera from the muscle would therefore reduce the cadmium burden of fishmeal.

Animals↗
PubMed2005

Molecular pathology of prostate cancer.

The molecular pathology of prostate cancer is complex; not only are multiple genes involved in its pathogenesis, but additional environmental factors such as diet and inflammation are also involved. The exhaustive research into prostate cancer to date has demonstrated a complex interaction of multiple genes and environmental factors, some of which may be more important in individual prostate cancer cases. This is an exciting era, with the emergence of new investigative tools such as DNA microarray technology and the application of the field of proteomics to the study of human cancers. Knowledge of genetic changes underlying the initiation, development, and progression of prostate cancer is accumulating rapidly. With increasing knowledge, it may be possible to distinguish indolent from aggressive prostate tumours by molecular fingerprinting. This review discusses the most consistently reported molecular pathological findings in hereditary and sporadic prostate cancer, together with new concepts and technologies.

Chromosome Aberrations↗
PubMed2004

Signalling pathways activated by all-trans-retinoic acid in acute promyelocytic leukemia cells.

Acute promyelocytic leukemia is a form of acute myelogenous leukemia, characterized by the t(15;17) chromososmal translocation and the presence of the abnormal PML-RARalpha fusion protein. All-trans-retinoic acid is a potent agent for the treatment of this fatal subtype of AML, and is particularly effective when combined with cytotoxic chemotherapy. The important biological activities of all-trans-retinoic acid in vitro and in vivo have provoked extensive studies over the years, aimed to define the mechanisms by which it induces its antileukemic effects. It is now well established that all-trans-retinoic acid when administered at pharmacological doses can reverse the dominant-negative effects that the PML-RARalpha oncoprotein exhibits on the functions of the wild type PML and RARalpha proteins. All-trans-retinoic acid induces gene transcription via retinoic acid responsive elements (RARE) that are present in the promoters of retinoid-responsive genes that ultimately result in the production of protein products that regulate leukemic cell differentiation and induce cell-cycle arrest. There is now accumulating evidence that additional signalling pathways are activated during all-trans-retinoic acid-treatment of cells, involving Stat-proteins, tyrosine kinases and mitogen-activated protein (Map) kinases. This review summarizes the current knowledge on the signalling cascades activated by all-trans-retinoic acid in APL cells. The clinical implications and potential translational applications from the accumulating knowledge in the field are also discussed.

Animals↗
PubMed1999

A tobacco plasma membrane calmodulin-binding transporter confers Ni2+ tolerance and Pb2+ hypersensitivity in transgenic plants.

All organisms require a minimal amount of metal ions to sustain their metabolism, growth and development. At the same time, their intrinsic metal-uptake systems render them vulnerable to toxic levels of metals in the biosphere. Using radiolabeled recombinant calmodulin as a probe to screen a tobacco cDNA library, we have discovered a protein designated NtCBP4 (Nicotiana tabacum calmodulin-binding protein) that can modulate plant tolerance to heavy metals. Structurally, NtCBP4 is similar to vertebrate and invertebrate K+ and to non-selective cation channels, as well as to recently reported proteins from barley and Arabidopsis. Here we report on the subcellular localization of NtCBP4 and the phenotype of transgenic plants overexpressing this protein. The localization of NtCBP4 in the plasma membrane was manifested by fractionating tobacco membranes on sucrose gradients or by aqueous two-phase partitioning, and subsequently using immunodetection. Several independent transgenic lines expressing NtCBP4 had higher than normal levels of NtCBP4. These transgenic lines were indistinguishable from wild type under normal growth conditions. However, they exhibited improved tolerance to Ni2+ and hypersensitivity to Pb2+, which are associated with reduced Ni2+ accumulation and enhanced Pb2+ accumulation, respectively. To our knowledge this is the first report of a plant protein that modulates plant tolerance or accumulation of Pb2+. We propose that NtCBP4 is involved in metal uptake across the plant plasma membrane. This gene may prove useful for implementing selective ion tolerance in crops and improving phytoremediation strategies.

Amino Acid Sequence↗
PubMed1990

Translatability of a plant-mRNA strongly influences its accumulation in transgenic plants.

Current knowledge of parameters affecting RNA stability is very restricted in plants. Here we investigated factors which might contribute to the stability of a particular plant messenger RNA. To this end, insertion and deletion mutants were made in two different exons and an intron of the transcribed region of a well characterised patatin gene (pgT5). Mutant genes were expressed under the control of a strong leaf-stem specific promoter (ST-LS1) and analysed in vivo in transgenic tobacco plants. Northern analysis revealed the importance of the translatability of the mature messenger RNA with respect to its accumulation in transgenic plants. Enlargement of the 3' non-translated region by several hundred base-pairs reduced the steady state mRNA level slightly; the introduction of a stop codon leading to premature termination of translation of the RNA led to a dramatic decrease of the steady state mRNA level.

Base Sequence↗
PubMed2001

Managing newborn health in the global community.

The largest health disparities in the world are found in maternal and neonatal mortality figures between the industrialized countries and the poorest sections of the poorest countries. Young lives would be saved if the skills and knowledge that have been accumulated by health workers around the world could be readily applied. The problems reside with lack of management resources rather than lack of scientific knowledge. "The Healthy Newborn: A Reference Manual for Program Managers" is a graduate course in management aimed at providing health to newborns and healthy newborns to communities.

Child Health Services↗
PubMed1992

Assessment of accumulated body burden of metals.

Knowledge of the body burden of a metal is important for evaluation of exposure and risk. Traditionally, the burden has been estimated through levels in blood, urine, hair, or shed teeth, or by mobilization tests. However, all these methods have limitations. In vivo methods for determination of cadmium in kidney by neutron activation analysis or X-ray fluorescence (XRF) reflect the burden, long-term exposure, and risk of toxic effect. In vivo determination by XRF of lead in fingerbone, tibia, or calcaneus reflect the long-term exposure, and should become a valuable tool in epidemiological studies, especially of chronic effects.

Body Burden↗
PubMedDate not supplied

Test wiseness.

Most test will have some questions worded in such a way that the recall button is automatically triggered. Answer those questions first, utilizing the body of knowledge that has been accumulated from the course content and assignments. Answer the remaining questions on the test by applying the answer analysis techniques outlined above. Review the answers and make the necessary changes. The combination of knowledge and answer analysis techniques will improve the ability of students to pass all types of examinations.

Cues↗
PubMed2006

Benefits of an external focus of attention: common coding or conscious processing?

We conducted two experiments to assess the effect attentional focus has on learning a complex motor skill and subsequent performance under secondary task loading. Participants in Experiment 1 learnt a golf putting task (300 practice trials) with a single instruction to either focus on their hands (internal focus) or the movement of the putter (external focus). No group differences were evident during learning or retention. Differences between the groups were only apparent under secondary task load; the external group's performance remained robust, while the internal group suffered a drop in performance. Verbal protocols demonstrated that the internal group accumulated significantly more internal knowledge and more task-relevant knowledge in general than the external group. Experiment 2 was designed to establish whether greater internal focus knowledge or greater explicit rule build up in general was responsible for performance breakdown. Two groups were presented with a set of six internal or external rules. Again, no performance differences were found during learning or retention. During the secondary task, both groups experienced performance deterioration. It was concluded that accumulation of explicit rules to guide performance was responsible for the internal group's breakdown in performance under secondary task loading and may be responsible for some of the performance differences reported previously.

Adult↗
PubMed2001

Effects of Cu2+, Ni2+, Pb2+, Zn2+ and pentachlorophenol on photosynthesis and motility in Chlamydomonas reinhardtii in short-term exposure experiments.

BACKGROUND: Heavy metals, especially copper, nickel, lead and zinc, have adverse effects on terrestrial and in aquatic environments. However, their impact can vary depending on the nature of organisms. Taking into account the ability of heavy metals to accumulate in sediments, extended knowledge of their effects on aquatic biota is needed. In this context the use of model organisms (often unicellular), which allows for rapid assessment of pollutants in freshwater, can be of advantage. Pentachlorophenol has been extensively used for decades as a bleaching agent by pulp- and paper industry. Pentachlorophenol tends to accumulate in the nature. We aim to determine if photosynthesis and motility can be used as sensitive physiological parameters in toxicological studies of Chlamydomonas reinhardtii, a motile green unicellular alga. It is discussed if photosynthesis and motility can be used as sensitive physiological parameters in toxicological studies. RESULTS: The concentrations studied ranged from 0.1 to 2.0 mg l-1 for copper, nickel, lead and zinc, and from 0.1 to 10.0 mg l-1 for pentachlorophenol. Exposure time was set to 24 h. Copper and pentachlorophenol turned out to be especially toxic for photosynthetic efficiency (PE) in C. reinhardtii. CONCLUSION: Copper and pentachlorophenol turned out to be especially toxic for PE in C. reinhardtii. Zinc has been concluded to be moderately toxic while nickel and lead had stimulatory effects on the PE. Because of high variance, motility was not considered a reliable physiological parameter when assessing toxicity of the substances using C. reinhardtii.

Animals↗
PubMed1995

Soft-tissue accumulation of lead in the blue tilapia, Oreochromis aureus (Steindachner), and the modifying effects of cadmium and mercury.

The interaction of mercury and cadmium with lead was investigated by exposing Oreochromis aureus to two heavy metals simultaneously. The chronic accumulation profile of lead was determined by analyzing the liver, brain, gill filaments, intestine, caudal muscle, spleen, trunk kidney, and gonads following exposure to lead alone and in mixtures with mercury and cadmium. Nominal exposure concentrations of lead were 0.05, 0.10, 0.50, and 1.00 mg/L. Mixtures of lead (0.50 or 0.05 mg/L) with cadmium (0.05 mg/L) and lead (0.50 or 0.05 mg/L) with mercury (0.05 mg/L) were also used. Following 140 d of exposure to lead, the highest concentrations of lead consistently accumulated in the trunk kidney. The concentration of lead in the kidney was decreased by coexposure to mercury or cadmium, but increased in the muscle and liver. Under all exposure regimes, the median concentration of lead in the muscle exceeded safety levels recommended for human consumption. In a food fish, such as O. aureus, a knowledge of toxic metal accumulation patterns is of great importance.

Animals↗
PubMed1995

Long-term mercury accumulation in the presence of cadmium and lead in Oreochromis aureus (Steindachner).

The effects of cadmium and lead on chronic mercury accumulation were investigated in O. aureus. After 140 days' exposure the accumulation of mercury in the liver, brain, gill filaments, intestine, caudal muscle, spleen, trunk kidney and eye was analysed. The exposure concentrations were 0.05, 0.10 and 0.20 mg/L for mercury alone. O. aureus was also exposed to mixtures of 0.05 mg/L mercury with lead (0.05 mg/L and 0.50 mg/L or cadmium (0.05 mg/L) and 0.10 mg/L mercury with 0.10 mg/L cadmium. In food fish, a knowledge of toxic metal accumulation patterns is of great importance because of their contribution to the human diet and, as fishmeal, to the diet of agricultural animals. The trunk kidney consistently accumulated higher concentrations of mercury than any of the other tissues investigated.

Animals↗
PubMed2002

Two distinct jacalin-related lectins with a different specificity and subcellular location are major vegetative storage proteins in the bark of the black mulberry tree.

Using a combination of protein isolation/characterization and molecular cloning, we have demonstrated that the bark of the black mulberry tree (Morus nigra) accumulates large quantities of a galactose-specific (MornigaG) and a mannose (Man)-specific (MornigaM) jacalin-related lectin. MornigaG resembles jacalin with respect to its molecular structure, specificity, and co- and posttranslational processing indicating that it follows the secretory pathway and eventually accumulates in the vacuolar compartment. In contrast, MornigaM represents a novel type of highly active Man-specific jacalin-related lectin that is synthesized without signal peptide or other vacuolar targeting sequences, and accordingly, accumulates in the cytoplasm. The isolation and cloning, and immunocytochemical localization of MornigaG and MornigaM not only demonstrates that jacalin-related lectins act as vegetative storage proteins in bark, but also allows a detailed comparison of a vacuolar galactose-specific and a cytoplasmic Man-specific jacalin-related lectin from a single species. Moreover, the identification of MornigaM provides the first evidence, to our knowledge, that bark cells accumulate large quantities of a cytoplasmic storage protein. In addition, due to its high activity, abundance, and ease of preparation, MornigaM is of great potential value for practical applications as a tool and bioactive protein in biological and biomedical research.

Amino Acid Sequence↗
PubMed2005

Women's sleep in health and disease.

A huge amount of knowledge about sleep has accumulated during the last 5 decades following the discovery of rapid eye movement (REM) sleep. Nevertheless, there are numerous areas of considerable ignorance. One of these concerns the particularities of sleep in women. Most basic and clinical studies have been performed in male subjects, and only very recently research groups around the world have addressed women's sleep in health and disease. In this review, we summarize the present knowledge on the influence of oestrogens on the brain and on the distinctive changes of sleep across the menstrual cycle, during pregnancy and menopause. In addition, studies in female rodents are reviewed as well as the knowledge on female peculiarities regarding the interactions between sleep regulation and age-related changes in circadian rhythms. We also address specific aspects of sleep loss and sleep disorders in women. Finally, very recent studies on the sociology of sleep are summarized and future directions in the field are discussed.

Adult↗
PubMed2005

Determination of select antidepressants in fish from an effluent-dominated stream.

Increasing evidence indicates widespread occurrence of pharmaceuticals and personal care products (PPCPs) in municipal effluent discharges and surface waters. Studies that characterize the fate and effects of PPCPs in aquatic systems are limited, and to our knowledge, data regarding pharmaceutical accumulation in fish of effluent-dominated ecosystems have not been previously reported. In the present study, fish populations were sampled from a reference stream and an effluent-dominated stream in north Texas, USA. Lepomis macrochirus, Ictalurus punctatus, Cyprinus carpio, and Pomoxis nigromaculatus were killed; the liver, brain, and lateral filet tissues dissected; and the tissues stored at -80 degrees C until analysis. Fish tissues were extracted using solid-phase extraction and then analyzed by gas chromatography-mass spectrometry in the negative chemical ionization mode. The selective serotonin reuptake inhibitors (SSRIs) fluoxetine and sertraline and the SSRI metabolites norfluoxetine and desmethylsertraline were detected at levels greater than 0.1 ng/g in all tissues examined from fish residing in a municipal effluent-dominated stream. To our knowledge, the present study is the first report of SSRI residues in fish residing within municipal effluent-dominated systems.

Animals↗