Preservation of episodic musical memory in a pianist with Alzheimer disease.
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Activities of Daily Living↗
Biomedical subjects
D Miranda
Publications and source records attributed to D Miranda.
CA-125 levels in predicting optimal cytoreductive surgery in patients with advanced epithelial ovarian carcinoma.
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Adult↗
Quantitative trait loci for lodging resistance, plant height and partial resistance to mycosphaerella blight in field pea (Pisum sativum L.).
With the development of genetic maps and the identification of the most-likely positions of quantitative trait loci (QTLs) on these maps, molecular markers for lodging resistance can be identified. Consequently, marker-assisted selection (MAS) has the potential to improve the efficiency of selection for lodging resistance in a breeding program. This study was conducted to identify genetic loci associated with lodging resistance, plant height and reaction to mycosphaerella blight in pea. A population consisting of 88 recombinant inbred lines (RILs) was developed from a cross between Carneval and MP1401. The RILs were evaluated in 11 environments across the provinces of Manitoba, Saskatchewan and Alberta, Canada in 1998, 1999 and 2000. One hundred and ninety two amplified fragment length polymorphism (AFLP) markers, 13 random amplified polymorphic DNA (RAPD) markers and one sequence tagged site (STS) marker were assigned to ten linkage groups (LGs) that covered 1,274 centi Morgans (cM) of the pea genome. Six of these LGs were aligned with the previous pea map. Two QTLs were identified for lodging resistance that collectively explained 58% of the total phenotypic variation in the mean environment. Three QTLs were identified each for plant height and resistance to mycosphaerella blight, which accounted for 65% and 36% of the total phenotypic variation, respectively, in the mean environment. These QTLs were relatively consistent across environments. The AFLP marker that was associated with the major locus for lodging resistance was converted into the sequence-characterized amplified-region (SCAR) marker. The presence or absence of the SCAR marker corresponded well with the lodging reaction of 50 commercial pea varieties.
Ascomycota↗
Clonal composition of human adamantinomatous craniopharyngiomas and somatic mutation analyses of the patched (PTCH), Gsalpha and Gi2alpha genes.
Craniopharyngioma is the most common childhood tumor and thought to arise from embryonic remnants of Rathke's pouch. The paucity of published data on the molecular basis of these tumors prompted us to examine 22 adamantinomatous craniopharyngiomas looking for genetic abnormalities. Using the X-linked polymorphic androgen receptor gene as a tool for X-chromosome inactivating analysis, we found that a subset of craniopharyngiomas are monoclonal and therefore are probably due to acquired somatic genetic defects. Thus, we investigated these tumours for mutations within three candidate genes, Gsalpha, Gi2alpha and patched (PTCH). Using single stranded conformational polymorphism (SSCP), denaturing gradient gel electrophoresis and direct sequencing, the presence of somatic mutations in these genes could not be demonstrated in any tumor. Our data indicate that a subset of craniopharyngiomas are monoclonal and the mutations in the PTCH, Gsalpha, and Gi2alpha contribute little if any to craniopharyngioma development.
Adenoma↗
Effect of Salmonella-infected human monocytes on natural killer cell cytotoxicity. In vitro studies.
Various chemicals, including some bacteria-derived components, modulate natural killer cell (NKC) activity. We have analyzed the effect of wild-type Ty2 and of mutant strain TYT1231 Salmonella typhi-infected monocytes (U937 cells and human autologous monocytes) on NKC cytotoxicity of peripheral blood mononuclear cell (PBMC) and highly purified NKC (HPNKC; CD16+/56+ > 95%; the rest corresponding to CD3+ T-cells). PBMC's co-culture with either S. typhi strain infected U937 cells (medium or non-infected U937 cells as controls) resulted in the induction of lymphocyte activated killer (LAK) cell activity showing cytotoxicity against target human NKC-resistant lymphoblastoid Daudi cell line. Comparable experiments using autologous monocytes gave similar results. Co-culture of HPNKC preparations with either S. typhi strain infected U937 cells resulted in increased LAK cell activity against target Daudi cells in each and everyone of the five samples tested; paired Student's t-test p < 0.01 for both times (20 and 40 h) tested. Similar to the results observed in the experiments using PBMC, we did not find significant differences in the ability between medium and non-infected cells, or between wild-type S. typhi Ty2 and mutant strain TYT1231 infected U937 cells, to induce LAK activity in HPNKC preparations. PBMC co-incubation with either S. typhi strain infected U937 cells or autologous monocytes resulted in significant increases in IL-12, TNF-alpha, and IFN-gamma secretion. In similar experiments using HPNKC samples instead, infected U937 cells significantly increased IL-12 and IFN-gamma, but not TNF-alpha secretion. PBMC co-incubation with non-infected U937 cells, but not with non-infected monocytes, significantly increased supernatant IL-12 and TNF-alpha levels (no significant changes in IFN-gamma were recorded). Secreted cytokines remained essentially unchanged after co-incubating HPNKC preparation with non-infected U-937 cells. Incubation of PBMC or HPNKC preparations with either S. typhi strain infected U937 cells failed to produce significant changes in the expression of NKC lineage (CD16+/56+) or activation (CD28+, CD69+ and CD95+) markers. The ability of infected monocytes to induce LAK activity, release NKC cytokines and upmodulate NKC's CD95+ marker expression was essentially the same for both infecting Salmonella strains used. These results suggest a role for NKC in the physiological defensive response against intracellularly infected monocytes representing, perhaps one of the earliest antimicrobial mechanisms of the innate immune system.
Acid Phosphatase↗
How clean is the home environment?: a tool to assess home hygiene.
The role of the home environment in the transmission of infectious diseases has been well described in the developing world but has received less attention in developed countries. An increasing focus on home hygiene has emerged in debates regarding the use of antimicrobial products in the home and the potential for development of resistance and in discussions regarding "when is clean too clean" and "what is clean." Studies are clearly needed to further explicate the role of the home in the spread of infectious agents, but before these can be conducted, adequate measurement tools are essential. This article describes extensive psychometric testing undertaken to develop valid and reliable methods and tools to measure home hygiene and focuses on a neighborhood that was primarily Spanish speaking in New York City. The Home Hygiene Assessment Tool described in this article can be used by clinicians and researchers to further elucidate the role of the home environment in the prevention and control of infections.
Colony Count, Microbial↗
Preventing medical errors: communicating a role for Medicare beneficiaries.
This study used a focus group methodology to examine how Medicare beneficiaries reacted to messages on specific kinds of preventive action, including those adopted by public and private section health organizations. Beneficiaries were asked to rank the messages on their own, and then to discuss their rankings in focus groups. The best-received messages advocated a collaborative patient-provider relationship. They also specified which actions to take, and how to implement them. The authors conclude that public health campaigns to reduce errors need not undermine trust in providers.
Aged↗
Assessing Medicare beneficiaries' readiness to make informed health plan choices.
The Transtheoretical Model (TTM, the "stage model") can guide development of programs to increase Medicare beneficiaries' readiness to make informed health plan choices. In this study, TTM staging algorithms were developed to assess readiness to engage in three types of informed choice: (1) learning about the Medicare program; (2) learning about Medicare health maintenance organizations (HMOs); and (3) reviewing different plan options. Stage of change based on all three algorithms is related to knowledge about the Medicare program and information-seeking. Findings provide evidence for the construct validity of the stage measures and for the applicability of the TTM to informed choice among beneficiaries.
Aged↗
Effect of Salmonella typhi wild type and O-antigen mutants on human natural killer cell activity.
We investigated the effect of glutaraldehyde-fixed Salmonella typhi Ty2 (Vi(-)) wild-type (World Health Organization's vaccine strain) and mutant strains MEI028 (rough, O-antigen(-)) and MEI012 [smooth (O-antigen(+)95%), immunomagnetically isolated NK cell preparations. Incubation of PBMC with each and every one of the S. typhi strains studied consistently and significantly, increased this cellular immune function, as well as the supernatant level of the various cytokines tested e.g. IFN-gamma, TNF-alpha, IL-10 and IL-12 (ELISA). In similar experiments, a significant increase in the cytolytic activity of HPNK cells was elicited by S. typhi Ty2 but not by mutant strain MEI028; neither of the cytokines assayed (IFN-gamma and TNF-alpha) was detected in the supernatant. Our results suggest that S. typhi O-antigen plays an essential role in a mechanism resulting in the direct activation of NK cell activity in HPNK cell preparations. However, the relative quantitative significance of this antigen in the direct stimulation of NK cell cytotoxicity expression in PBMC samples is less clear, as it appears that in this case bacterial-induced monocyte-released cytokines plays a most important role. Incubation with S. typhi Ty2 or MEI028 elicited significant expression of CD69, an early marker of NK cell activation, in PBMC but not in HPNK cell samples (flow cytometry); in similar experiments, the expression of CD16/56 and activation marker CD25 remained essentially unchanged.
Adult↗
Cytogenetic damage related to low levels of methyl mercury contamination in the Brazilian Amazon.
The mercury rejected in the water system, from mining operations and lixiviation of soils after deforestation, is considered to be the main contributors to the contamination of the ecosystem in the Amazon Basin. The objectives of the present study were to examine cytogenetic functions in peripheral lymphocytes within a population living on the banks of the Tapajós River with respect to methylmercury (MeHg) contamination, using hair mercury as a biological indicator of exposure. Our investigation shows a clear relation between methylmercury contamination and cytogenetic damage in lymphocytes at levels well below 50 micrograms/gram, the level at which initial clinical signs and symptoms of mercury poisoning occur. The first apparent biological effect with increasing MeHg hair level was the impairment of lymphocyte proliferation measured as mitotic index (MI). The relation between mercury concentration in hair and MI suggests that this parameter, an indicator of changes in lymphocytes and their ability to respond to culture conditions, may be an early marker of cytotoxicity and genotoxicity in humans and should be taken into account in the preliminary evaluation of the risks to populations exposed in vivo. This is the first report showing clear cytotoxic effects of long-term exposure to MeHg. Although the results strongly suggest that, under the conditions examined here, MeHg is both a spindle poison and a clastogen, the biological significance of these observations are as yet unknown. A long-term follow-up of these subjects should be undertaken.
Adolescent↗
In vitro effect of bacterial lipopolysaccharide on the cytotoxicity of human natural killer cells.
Preincubation with a number of mediators of infection, such as Gram negative bacteria (S. typhi), bacterial lipopolysaccharide (LPS), tumor necrotic factor-alpha (TNF-alpha), and interleukin-2 (IL-2), significantly increases natural killer (NK) cell activity in samples of human peripheral blood mononuclear cells (PBMC), without changing the levels of either the phenotypic CD16/56 or stimulatory CD25 marker. We now report similar results after preincubation of highly purified NK cell preparations (CD16 + 56 > 95%; the rest corresponding to CD3+ T-cells) with either S. typhi, TNF-alpha or IL-2. However, in similar experiments, LPS inhibits, in a dose-dependent manner (final conc. 2.5, 5.0 or 10.0 micrograms/mL), NK cell cytotoxicity against K-562 tumor cells. Preincubation of purified NK cells with LPS (25 micrograms/mL; 10 and 30 min) produced significant alterations in the tyrosine phosphorylation/dephosphorylation pattern of several intracellular proteins, including a significant increase (10 min) in the phosphorylation of the 120; 100; 72 and 59 kDa proteins, followed (30 min) by the essentially complete desphosphorylation of the p59 protein. Qualitatively similar results were obtained at lower LPS concentrations e.g., range 2.5 to 20 micrograms/mL. The absence of phosphoproteins in the 40-44 kDa range, known to be present after incubation of monocytes with LPS, raises the possibility that these "class" of proteins may be critical in explaining the LPS inhibitory effect on NK lytic function. Our finding may contribute to a better understanding of the mechanisms involved in the complex in vivo interaction between LPS, monocytes and NK cells.
Adult↗
Endomyocardial fibrosis in Egypt: an illustrated review.
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Bibliographies as Topic↗
Volume regulation in NIH/3T3 cells not expressing P-glycoprotein. I. Regulatory volume decrease.
Exposure of NIH/3T3 fibroblasts not expressing P-glycoprotein to 50, 30, 20, and 10% hyposmotic solutions led to cell volume increases of 70, 32, 21, and 12%, respectively. After swelling, NIH/3T3 cells exhibited regulatory volume decrease (RVD), attaining complete volume recovery after 30 min except in 50% hyposmotic solution, in which volume recovery was 76%. RVD was accelerated by gramicidin and inhibited by the Cl channel blockers 5-nitro-2-(3-phenylpropylamino)-benzoic acid, 1,9-dideoxyforskolin, dipyridamole, and niflumic acid and by the K channel, blocker quinidine. RVD was reduced 15% by removal of extracellular Ca. The pathway opened by hypotonicity was highly permeable to K and Rb and only partly permeable to other cations. Most anions were able to permeate, with a permeability ranking of nitrate > benzoate = iodide > thiocyanate > chloride > > gluconate. The pathway was permeable to neutral amino acids, with a permeability ranking of glycine > alanine > glutamate > taurine > gamma-aminobutyric acid > glutamine. The pathway was not permeable to basic amino acids. These results show that, despite the absence of P-glycoprotein, NIH/3T3 cells exhibit RVD with properties similar to those expressed in most cell types.
3T3 Cells↗
Volume regulation in NIH/3T3 cells not expressing P-glycoprotein. II. Chloride and amino acid fluxes.
The osmolyte function of amino acids and Cl in native NIH/3T3 cells not expressing the P-glycoprotein was examined by investigating the free amino acid concentration and the swelling-activated efflux of [3H]taurine, as representative of amino acids, and of 125I, as a tracer for Cl. Taurine and 125I efflux was activated by 20 and 30% hyposmotic solutions. At 50% hyposmotic solutions, the osmolyte pool was essentially depleted. The Cl channel blockers 5-nitro-2-(3-phenylpropyl-amino)benzoic acid, 1,9-dideoxyforskolin, dipyridamole, and niflumic acid inhibited the release of the two osmolytes by 80-95%. 4,4'-Diisothiocyanostilbene-2,2'-disulfonic acid (400 microM) decreased the efflux of taurine 80% without affecting that of 125I. Linolenic and arachidonic acids (5-20 microM) showed a concentration-dependent inhibitory effect on taurine and 125I fluxes. Omission of Ca decreased osmolyte fluxes by 16%. Verapamil inhibited the osmolyte release only at 500 microM. Nimodipine at 25 and 50 microM decreased the release of [3H]taurine and 125I by approximately 60 and 80%, respectively, but this effect was independent of the presence of extracellular Ca. These results indicate that amino acids and Cl function as osmolytes during regulatory volume decrease in native NIH/ 3T3 cells.
3T3 Cells↗
Oncocytic adenocarcinoma of the ovary.
A rare case of ovarian adenocarcinoma with extensive oncocytic differentiation is presented. Light and electron microscopy examination and a specific stain for mitochondria (chromotrope-alcian blue) confirmed the diagnosis. The tumour cells revealed abundant granular and eosinophilic cytoplasm containing a large number of mitochondria. The tumour had a malignant infiltrative pattern and cellular atypia.
Adenocarcinoma↗
Association between Helicobacter and gastric ulcer disease of the pars esophagea in swine.
BACKGROUND & AIMS: Swine present spontaneously peptic ulcer in the gastric pars esophagea and are frequently colonized by a spiral bacterium that is of the same species as Helicobacter heilmannii type 1. This organism is also observed in the gastric mucosa of patients with gastric symptoms and who present with gastritis at histology. The aim of this study was to investigate the association between the presence of H. heilmannii type 1 and lesions of the pars esophagea. METHODS: H. heilmannii type 1 infection was investigated by mouse inoculation, urease test, and carbolfuchsin stain in 20 stomachs with ulcer, 30 stomachs with preulcer lesions, and 20 stomachs with a macroscopically normal pars esophagea. RESULTS: The microorganism was more frequently found in the stomachs with ulcer (100%) and in those with preulcer lesions (90%) than in stomachs with macroscopically normal pars esophagea (35%). Histological alterations were observed in the pars esophagea and in the glandular regions of bacterium-positive stomachs. CONCLUSIONS: It has been shown that the microorganism is strongly associated with naturally occurring ulcer and preulcer lesions of the pars esophagea of swine, which raises the possibility that the bacterium is an important factor in the pathogenesis of these lesions.
Animals↗
Activation of protein tyrosine kinase: a possible requirement for fixed-bacteria and lipopolysaccharide-induced increase in human natural killer cell activity.
Preincubation of peripheral blood lymphocytes (PBL) from drug-free, healthy volunteers with either the protein tyrosine kinase inhibitor genistein (GNT, n = 10, final concentration 200 microM) or the protein kinase A activator dybutiryl-cyclic-AMP (cAMP, n = 11, final concentration 10 microM), resulted in a significant inhibition of natural killer cell activity (NKCA, expressed as percentage of specific chromium release). With the exception of 4 out of the 11 cAMP-treated samples, individual values for NKCA in the drug preincubated specimens were at least 20% below the same subject baseline activity; furthermore, NKC lytic function was non-detectable in 4 out of the 10 and in 1 out of the 11 samples pretreated with either GNT or cAMP, respectively. PBL preincubation with glutaraldehyde-fixed Gram-negative bacteria (GNB, n = 13, final GNB-to-effector cell ratio of 50 : 1) resulted in a statistically significant increase in NKCA (baseline (x +/- SD) of 21.6 +/- 16.4 and bacteria treated samples of 41.5 +/- 24.6, respectively, Student's paired t-test p < 0.05). At least a 20% increase in NKC lytic function over its own baseline value was recorded for 11 out of the 13 samples tested (Table 1). Preincubation with GNB and GNT (5 samples) not only blocked the immunostimulant effects of GNB (Student's paired t-test p < 0.05), but in most cases individual values for NKCA were similar to those recorded for GNT-only treated samples. Use of cAMP instead of GNT also blocked, but to a smaller extent, the GNB-produced increases in NKC lytic function (paired Student's t-test < 0.05). PBL preincubation with lipopolysaccharide (LPS, n = 11, final concentration 50 micrograms/ml) resulted in a statistically significant increase in NKCA (baseline (x +/- SD) of 20.7 +/- 14.1 and LPS treated samples of 39.2 +/- 18.5, respectively, Student's paired t-test < 0.05). At least a 20% increase in NKCA over its own baseline value was observed for each and everyone of the 11 samples studied (Table 2). Addition of LPS and GNT to the incubation mixture resulted not only in inhibition of the NKCA upmodulating LPS effects (Student's paired t-test p < 0.05), but each and everyone of the individual samples' NKCA were, in fact, significantly lower than their corresponding control baseline values and similar to those recorded for GNT-only treated samples. However, the use of LPS and cAMP (Table 2) produced less dramatic results, significant inhibition of LPS effect were recorded in only 2 samples (Nos 8 and 10), and individual NKCA in the remaining 3 specimens was significantly higher than the corresponding baseline value. Whereas experimental results obtained with GNT support the involvement of PTK-dependent pathways in the stimulation of human NKCA produced by GNB and LPS, cAMP experiments suggest modulation of PKA-dependent pathways as responsible for the decrease in NK lytic function produced by a number of chemicals involved in the pathophysiology associated with certain forms of stress, including septic shock. Further research in this area could help in the rational design of pharmacological approaches for the treatment of these conditions.
Adult↗
Evidence of early nervous system dysfunction in Amazonian populations exposed to low-levels of methylmercury.
There is increasing concern about the potential neurotoxic effects of exposure to methylmercury in Amazonian populations due to mercury (Hg) release from gold-mining activities. A preliminary study was undertaken in two villages on the Tapajos River, an effluent of the Amazon, situated over 200 km downstream from the extraction areas. The study population included 29 young adults (< or = 35 years), 14 women and 15 men, randomly chosen from a previous survey. Hair analyses were conducted with cold vapor atomic fluorescence spectrophotometry. Total hair Hg (THg) varied between 5.6 micrograms/g and 38.4 micrograms/gl, with MeHg levels from 72.2% to 93.3% of the THg. A quantitative behavioural neurophysiological test battery, designed for use under standard conditions, in an area without electricity and for persons with minimal education was administered to all participants. The results of visual testing showed that although all participants had good near and far visual acuity, color discrimination capacity (Lanthony D-15 desaturated panel) decreased with increasing THg (F = 4.1; p = 0.05); near visual contrast sensitivity profiles (Vistech 6000) and peripheral visual field profiles (Goldman Perimetry with Targets I and V) were reduced for those with the highest levels of THg. For the women, manual dexterity (Santa Ana, Helsinki version) decreased with increasing THg (F = 16.7; p < 0.01); this was not the case for the men. Although the women showed a tendency towards reduced grip strength, muscular fatigue did not vary with THg for either sex. The findings of this study demonstrate that it is possible, using a sensitive test battery, to detect alterations in nervous system functions, consistent with knowledge on Hg toxicity, at levels below the currently recognized threshold of 50 micrograms/g THg.
Adolescent↗