Mean Cell Volume (mean + cell_volume)

Distribution by Scientific Domains

Selected Abstracts

Hematotoxic and hepatotoxic effects of dichlorvos at sublethal dosages in rats

Ismail Celik
Abstract The present study was designed to understand the effects of sublethal concentrations of dichlorvos (DIC) on hematological constituent [red blood corpuscles, white blood corpuscles (WBC), mean cell volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, platelet counts, hemoglobin and hematocrite levels] and serum damage marker enzymes (aspartate aminotransferase, alanin aminotransferase, alkaline phosphatase, and lactate dehydrogenase) in rats at subacute period under laboratory conditions. DIC at dosages of 5 and 10 ppm was administered orally to six male rats ad libitum during the tests for 4 weeks consecutively. According to the results, DIC treatments increased significantly the levels of serum marker enzyme activities, whereas they did not change hematologic constituent except for WBC number treated with both dosages of DIC. The observations presented led us to conclude that the administrations of subacute DIC induced the levels of damage marker enzymes and leukocytosis. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2009. [source]

Use of advanced red blood cell and reticulocyte indices improves the accuracy in diagnosing iron deficiency in pregnant women at term

Mari Ervasti
Abstract Objectives:, Detection of iron deficiency during pregnancy with hemoglobin (Hb) and serum measurements is insignificant as the measurements may be affected by e.g. hemodilution or accelerated erythropoiesis. This study tests whether cell indices will give a more reliable measure of iron deficiency in pregnant women at term. Methods:, The population was 202 pregnant women. Using the ADVIA 120 hematology system, Hb, mean cell volume (MCV), percentage of hypochromic red blood cells (%HYPOm) and reticulocytes (%HYPOr), and cellular hemoglobin in reticulocytes (CHr) were tested. Additionally, transferrin saturation (TfSat), ferritin, and transferrin receptor (TfR) were analyzed. Receiver operating characteristic (ROC) curves and area under the ROC curves (AUC) were used as statistical methods. Results:, When TfSat (,11%) was used as the reference test for iron deficiency, %HYPOm and CHr had a sensitivity of 58.1% and 80.7%, while the specificities were 82.6% and 71.3%, respectively. Additionally, the AUC values were %HYPOr 0.80, CHr 0.79, ferritin 0.77, %HYPOm 0.75, TfR 0.67, MCV 0.63 and Hb 0.64. The results provided by the cell indices alone (%HYPOm or CHr) were in good agreement with the results based on the usage of a combination of three commonly used tests (Hb, MCV, ferritin). Conclusions:, This study suggests that the most practical way to diagnose iron deficiency in pregnant women at term is to use cell indices such as CHr and %HYPOm provided by the automated hematological analyzer. Further studies are needed to determine the usefulness of the cell indices in diagnosing iron deficiency longitudinally during the course of pregnancy. [source]

Effect of Clostridium perfringens epsilon toxin on MDCK cells

Erika Borrmann
Abstract Epsilon toxin is one of the major lethal toxins produced by Clostridium perfringens type D and B. It is responsible for a rapidly fatal disease in sheep and other farm animals. Many facts have been published about the physical properties and the biological activities of the toxin, but the molecular mechanism of the action inside the cells remains unclear. We have found that the C. perfringens epsilon toxin caused a significant decrease of the cell numbers and a significant enlargement of the mean cell volume of MDCK cells. The flow cytometric analysis of DNA content revealed the elongation of the S phase and to a smaller extent of the G2+M phase of toxin-treated MDCK cells in comparison to untreated MDCK cells. The results of ultrastructural studies showed that the mitosis is disturbed and blocked at a very early stage, and confirmed the toxin influence on the cell cycle of MDCK cells. [source]

Temporal dynamics and growth of Actinophrys sol (Sarcodina: Heliozoa), the top predator in an extremely acidic lake

Summary 1. The in situ abundance, biomass and mean cell volume of Actinophrys sol (Sarcodina: Heliozoa), the top predator in an extremely acidic German mining lake (Lake 111; pH 2.65), were determined over three consecutive years (spring to autumn, 2001,03). 2. Actinophrys sol exhibited pronounced temporal and vertical patterns in abundance, biomass and mean cell volume. Increasing from very low spring densities, maxima in abundance and biomass were observed in late June/early July and September. The highest mean abundance recorded during the study was 7 × 103 Heliozoa L,1. Heliozoan abundance and biomass were higher in the epilimnion than in the hypolimnion. Actinophrys sol cells from this acidic lake were smaller than individuals of the same species found in other aquatic systems. 3. We determined the growth rate of A. sol using all potential prey items available in, and isolated and cultured from, Lake 111. Prey items included: single-celled and filamentous bacteria of unknown taxonomic affinity, the mixotrophic flagellates Chlamydomonas acidophila and Ochromonas sp., the ciliate Oxytricha sp. and the rotifers Elosa worallii and Cephalodella hoodi. Actinophrys sol fed over a wide-size spectrum from bacteria to metazoans. Positive growth was not supported by all naturally available prey. Actinophrys sol neither increased in cell number (k) nor biomass (kb) when starved, with low concentrations of single-celled bacteria or with the alga Ochromonas sp. Positive growth was achieved with single-celled bacteria (k = 0.22 ± 0.02 d,1; kb = ,0.06 ± 0.02 d,1) and filamentous bacteria (k = 0.52 ± <0.01 d,1; kb = 0.66 d,1) at concentrations greater than observed in situ, and the alga C. acidophila (up to k = 0.43 ± 0.03 d,1; kb = 0.44 ± 0.04 d,1), the ciliate Oxytricha sp. (k = 0.34 ± 0.01 d,1) and in mixed cultures containing rotifers and C. acidophila (k = 0.23 ± 0.02,0.32 ± 0.02 d,1; maximum kb = 0.42 ± 0.05 d,1). The individual- and biomass-based growth of A. sol was highest when filamentous bacteria were provided. 4. Existing quantitative carbon flux models for the Lake 111 food web can be updated in light of our results. Actinophrys sol are omnivorous predators supported by a mixed diet of filamentous bacteria and C. acidophila in the epilimnion. Heliozoa are important components in the planktonic food webs of ,extreme' environments. [source]

Foetal haemoglobin in homozygous sickle cell disease: a study of patients with low HBF levels*

A. Donaldson
High foetal haemoglobin (HbF) levels are believed to ameliorate the manifestations of homozygous sickle cell (SS) disease. The corollary implies that patients with low HbF levels should have more severe clinical courses. We investigated this in a retrospective study of 50 Jamaican patients with steady-state HbF levels below 1% compared with a control group (A) of 54 subjects with steady-state HbF levels between 2.5 and 3.4% (around the 25th centile for our population), and a second control group (B) of 60 patients with steady-state HbF levels between 4.6 and 5.2% (around the 50th centile). Comparisons across the groups indicated significantly fewer females in the study group (16, 50 and 57%, respectively). Examination for haematological trends across the groups showed positive linear trends for haemoglobin (Hb) (P=0.004), packed cell volume (PCV) (P=0.01), mean cell volume (MCV) (P=< 0.001), mean cell haemoglobin (MCH) (P=< 0.001) and a negative trend for haemoglobin A2 (P=0.03). Clinically, there were no differences in the incidence of painful crises, abdominal crises and the acute chest syndrome, but leg ulcers were significantly less frequent in the study group (P=0.04). Therefore low HbF levels do not appear to increase the clinical severity of SS disease and may be protective against leg ulceration. [source]

Effect of cyclosporin A in Lewis rats in vivo and HeLa cells in vitro

Andrea Sovcikova
Abstract The aim of this study was to compare the effect of cyclosporin A (CsA) in inbred Lewis rats with published assessment of immunotoxicity in ,classical' outbred Wistar rats. A second purpose was to consider the contribution of a panel of in vitro assays in cell cultures when added to an immunotoxicity study in vivo. The in vivo effect of CsA was investigated in a 28-day subacute immunotoxicity study in male Lewis rats at three different concentrations: 1.25, 5 and 20 mg kg,1. The highest dose of CsA exceeded the maximum tolerated dose. A drop in body, spleen and popliteal lymph node weight of exposed animals displayed symptoms of toxicity. At a high toxic dose, haematological changes showed a decrease in the leucocyte count and in the percentage of lymphocytes, and an increase in the percentage of polymorphonuclear leucocytes. The haematocrit was significantly dose-dependently suppressed in all rats exposed to CsA. A similar dose-dependent depression of the mean cell volume of erythrocytes was found in rats given high and middle doses of CsA. The phagocytic activity of polymorphonuclear leucocytes and monocytes also was significantly dose-dependently suppressed. No significant changes in primary antibody response to sheep erythrocytes or in vitro proliferative response of spleen lymphocytes to mitogens were found in those rats. A battery of in vitro cytotoxicity methods was selected for the evaluation of metabolic and functional activity of subcellular organelles (mitochondria, lysosomes) and for the detection of drug-induced superoxide-mediated damage in HeLa cells. This cell line was chosen because it has a lower activity of superoxide dismutase (SOD) than normal cells and is sufficiently sensitive for the detection of the induction of oxygen radicals. The in vitro results indicated a direct relationship between CsA cytotoxicity and a change in the mitochondrial enzyme activity, as well as an induction of superoxide production. The results of the study indicated that a combination of selected in vivo and in vitro methods is an inexpensive way to obtain more complex information on cell status affected by xenobiotics. Copyright © 2002 John Wiley & Sons, Ltd. [source]


Sébastien Mas
Diel variations of cellular optical properties were examined for cultures of the haptophyte Imantonia rotunda N. Reynolds and the diatom Thalassiosira pseudonana (Hust.) Hasle et Heimdal grown under a 14:10 light:dark (L:D) cycle and transferred from 100 ,mol photons · m,2 · s,1 to higher irradiances of 250 and 500 ,mol photons · m,2 · s,1. Cell volume and abundance, phytoplankton absorption coefficients, flow-cytometric light scattering and chl fluorescence, and pigment composition were measured every 2 h over a 24 h period. Results showed that cell division was more synchronous for I. rotunda than for T. pseudonana. Several variables exhibited diel variability with an amplitude >100%, notably mean cell volume for the haptophyte and photoprotective carotenoids for both species, while optical properties such as flow-cytometric scattering and chl a,specific phytoplankton absorption generally showed <50% diel variability. Increased irradiance induced changes in pigments (both species) and mean cell volume (for the diatom) and amplified diel variability for most variables. This increase in amplitude is larger for pigments (factor of 2 or more, notably for cellular photoprotective carotenoid content in I. rotunda and for photosynthetic pigments in T. pseudonana) than for optical properties (a factor of 1.5 for chl a,specific absorption, at 440 nm, in I. rotunda and a factor of 2 for the absorption cross-section and the chl a,specific scattering in T. pseudonana). Consequently, diel changes in optical properties and pigmentation associated with the L:D cycle and amplified by concurrent changes in irradiance likely contribute significantly to the variability in optical properties observed in biooptical field studies. [source]

Ageing of substantia nigra in humans: cell loss may be compensated by hypertrophy

C. R. Cabello
In a stereological study of the human substantia nigra (SN), the total number of melanin-positive and melanin-negative neurones from 28 male subjects aged 19,92 years was estimated using a uniform sampling design and optical disectors. There was a significant decrease in the total number of melanin-positive neurones as a function of age (r2=0.18, residual-CV=0.35, 2P=0.032). Using the rotator method, the size distribution of the melanin-positive neurones was estimated and showed a significant difference in mean cell volume of melanin-positive neurones between the seven youngest (21,077 µm3) and the seven oldest individuals (32,011 µm3), 2P=0.022. Using a combination of the total number of melanin-positive neurones and their size distribution, the total perikaryon volume of melanin-positive neurones could be estimated and showed no decrease with increasing age (r2=0.01, residual-CV=0.41, 2P=0.62). Age-related decline in dopamine-transporter neurones within the SN might explain the occurrence of extrapyramidal symptoms in many elderly individuals. Although age-related cell hypertrophy is usually considered to be an indication of cell degeneration or necrosis, this might not always be the case. The fact that motor symptoms, although present in many of the elderly, are of a limited nature despite the high percentage of lost neurones could be due to a compensatory increase in the cell body of dopamine-producing SN neurones. Thus, the total amount of cell substance capable of producing the essential transmitters might not be reduced to a critically low level as a result of ageing. [source]

Quantitative cell and matrix changes in human humeral head osteoarthritic cartilage

APMIS, Issue 10 2000
A new quantitative method was devised both to establish an objective standard for morphometric diagnosis and to determine the extent of degeneration in osteoarthritic cartilage. Eight normal and forty-eight osteoarthritic humeral heads, subsequently confirmed by light microscopy, were obtained at necropsy. The articular cartilage was observed in situ with a laser scanning confocal microscope (LSCM) and morphometric measurements determined cell density (cells/mm), cell volume fraction (%) and mean cell volume (,3). The osteoarthritic cartilages were classified according to the following four characteristics: increase in thickness, increase in cell volume fraction, decrease in cell volume fraction, and fibrous pannus. Deviations in cell density and cell volume fraction from normal means were calculated as extent of degeneration. Our present approach aims to provide valuable clues, such as objective stereological information and a unique reference for biochemical and traditional morphlogical analyses, that clinicians will be able to use in combination with other methods in order to establish a reliable diagnosis. [source]

Biochemical responses of matrinxćBrycon cephalus (Günther, 1869) after sustained swimming

Araceli Hackbarth
Abstract Juvenile matrinxć, Brycon cephalus, were submitted to sustained swimming for 72 days at 1.0 body length s,1. Exercised fish (EF) grew more than non-EF and their feed conversion ratio (FCR) improved; haematological responses demonstrated a decrease in haemoglobin and mean cell haemoglobin contents and increase in the mean cell volume. In the plasma, sodium, ammonia and amino acid concentrations increased; plasma triglycerides decreased while free fatty acids increased. Liver glucose, free amino acids, ammonia, the rate protein per fish weight and total lipid content increased, while the glycogen per fish ratio declined. Glutamate dehydrogenase (GDH) activity increased while pyruvate kinase (PK) and lactate dehydrogenase (LDH) decreased. White muscle glucose, lactate, the glycogen per fish-weight ratio and total lipid content exhibited a decrease in their values; ammonia, free amino acids and the protein per fish-weight ratio increased. GDH and PK decreased their activities. In the red muscle glycogen store, the glycogen per fish-weight ratio and glucose were reduced. Juvenile matrinxćs, under sustained swimming, were physiologically and biochemically adapted to exercise as indicated by improved blood flow, transport and oxygen uptake, FCR, amino acid and protein incorporation and growth. Continuous exercise is a good practice for B. cephalus cultivation. [source]

Co-inheritance of ,+ -thalassaemia and sickle trait results in specific effects on haematological parameters

Sammy Wambua
Abstract Both the sickle cell trait (HbAS) and ,+ -thalassaemia are common in many tropical areas. While their individual haematological effects are well described, few studies describe their effects when inherited together. We present data from the Kenyan coast, which suggest that HbAS and ,+ -thalassaemia may interact to produce specific effects on haematological parameters. Overall, the difference in Hb concentrations between non-thalassaemics (,,/,,) and ,+ -thalassaemia homozygotes (,,/,,) was greater in non-HbAS (HbAA) (0·63 g/dl) than in HbAS children (0·25 g/dl). HbAS also ameliorated both the reduced mean cell volume and mean cell haemoglobin normally associated with the ,,/,, genotype. Potential mechanisms and implications are discussed. [source]

Are there clinical phenotypes of homozygous sickle cell disease?

Neal Alexander
Summary The distribution of clinical features was examined in subjects with homozygous sickle cell (SS) disease in the Jamaican Cohort Study to determine whether there is evidence of distinct clustering of symptoms or clinical phenotypes. A twofold model yielded groups that could be interpreted as painful crisis or leg ulcer phenotypes and 78% of patients were classified with 95% confidence into one of these. The painful crisis phenotype also manifested higher frequencies of dactylitis, meningitis/septicaemia, acute chest syndrome and stroke. Attempts to define a three-group model were less convincing although 43% of patients could be allocated with 95% confidence. The three-group model essentially divided subjects with the leg ulcer phenotype into subgroups with higher and lower frequencies of painful crisis, dactylitis, meningitis/septicaemia and acute chest syndrome. In the three-group model, the painful crisis phenotype had lower total haemoglobin, fetal haemoglobin, mean cell volume and higher reticulocytes but there was no apparent influence of alpha thalassaemia or beta globin haplotype. Both environmental and genetic factors are likely to contribute to most manifestations of SS disease and the evidence for different clinical phenotypes suggests that a search for associated genetic polymorphisms may provide insights into the mechanisms of clinical variability in SS disease. [source]

,-Thalassaemia intermedia in a Turkish girl: homozygosity for G,A substitution at +22 relative to the ,-globin cap site

R. Öner
We provide the first description of a homozygote patient for the G,A substitution in the 5, UTR of the ,-globin gene. The proband was a 17-year-old girl with ,-thalassaemia intermedia who had never received a blood transfusion. The physical examination revealed a well-developed women with no facial or bony abnormalities. There was mild paleness and mild splenomegaly which was 2 cm below the costal margin. The haemoglobin (Hb) was 7·6 g/dl, Hb A2 5·4% and Hb F 14·6% of the total Hb. The Hb A2 of both parents was 3·5%. The Hb F level in the mother and father were 0·9, 1·2% and the mean cell volume (MCV) value was 70 and 72 fl respectively. DNA analysis of the ,-gene region of the propositus revealed homozygosity for a G,A substitution at nucleotide +22 relative to the ,-gene cap site, within a functional downstream region that was referred to as the DCE (downstream core element). In addition to the data obtained previously from in vitro transcription assays, clinical findings and in vivo expression studies gave some valuable clues about the effect of +22 G,A mutation on the expression of ,-gene. Phenotypic expression of this homozygous patient is highly suggestive that G,A substitution at nt +22 confers a relatively mild (silent) ,+ -thalassaemia phenotype. [source]

Randomized double-blind controlled trial on the effects on iron status in the first year between a no added iron and standard infant formula received for three months,

DP Tuthill
Recent research has not only questioned the necessity of iron supplementation in human milk substitutes prior to weaning, but also suggested some potential adverse effects. This study investigated the hypothesis that infant formula need not contain added iron in the first 3 mo. Healthy term infants were recruited into a double-blind controlled trial and randomized to receive either a new no added iron formula (New; <0.1 mg Fe 100 ml,1) or a standard formula (Standard; 0.5 mg Fe 100 ml,1) for the first 3 mo of life. A breastfed reference group was also studied. Iron status was assessed at 3 and 12 mo from heel-prick capillary blood samples evaluated by full blood-count analysis, including reticulocytes and serum ferritin. In total, 149 infants were entered (51 New, 49 Standard, 49 breastfed) with no differences between the groups in gender distribution, birthweight, gestation or numbers completing the study. There were no significant differences between the principal outcome measures: mean values for haemoglobin, mean cell volume and ferritin, between the two formula-fed groups, and the proportion with a haemoglobin level <11 g dl,1 or ferritin <10 ,g l,1 did not differ. Conclusion: The use of a "no added iron" infant formula in place of an iron-fortified formula during the first 3 mo of life did not clinically affect iron status at 3 and 12 mo of age. The universal supplementation of formulae with iron during this initial period needs further consideration. [source]