Differences In Mean Corpuscular Volume Research Articles

Changes in hematological parameters in free-living pigeons (Columba livia f. urbana) during the breeding cycle

The blood parameters—red blood cell (RBC) count, hematocrit (Ht), hemoglobin concentration (Hb), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC)—were studied for the first time in free ranging pigeons Columba livia f. urbana. The aim of the study was to establish a set of reference values for this ubiquitous urban species and to examine a potential influence of the factors such as sex and phase of the breeding cycle on the hematological parameters. Blood was sampled from the adult individuals of both sexes during the breeding cycle. Significant variations in Ht and Hb were observed, while RBC count remained unchanged. The lower hematocrit value and hemoglobin concentration found in both males and females during molt probably resulted from the increase of plasma volume not accompanied by an increase in RBC. On the other hand, a significant physiological stress of nutritional deficiency during this energy-consuming stage may manifest itself in the decreased Ht and Hb values. The higher values of Ht and Hb during the laying phase could be related to the dehydration status. There were no overall differences in MCV, MCH, and MCHC values in either of the breeding stage. A lack of sex dimorphism in the measured and calculated blood parameters was apparent. Data collected herein contribute to the better understanding of general physiology of the ubiquitous urban species. The knowledge of variation in the blood indexes with respect to sex and breeding stage is crucial before blood parameters can provide an useful information on physical condition of the bird.

Influences of hypercholesterolemia on red cell indices and erythrocyte sedimentation rate in elderly persons

Background: We investigated whether hypercholesterolemia influenced the values of mean corpuscular volume (MCV) and erythrocyte sedimentation rate (ESR). Methods: A total of 463 nonanemic elderly persons were evaluated regarding red cell indices, ESR, and ESR-related parameters, such as fibrinogen, albumin, and C-reactive protein (CRP). Results: There were no significant differences in MCV between elderly men with and without hypercholesterolemia (≥240 mg/dl) nor between the subjects with a marked increase of serum cholesterol concentrations (≥260 mg/dl) and with severely lowered cholesterol concentrations (<155 mg/dl). ESR in elderly men with hypercholesterolemia averaged 12.3±6.8 mm/h, which were significantly higher than in those without hypercholesterolemia (6.0±4.7 mm/h, p<0.01). ESR averaged threefold higher in the elderly men with serum cholesterol concentration ≥260 mg/dl versus those with serum cholesterol concentrations <155 mg/dl, although no significant differences were observed in fibrinogen, albumin, and CRP values between the two groups. Serum cholesterol concentrations were higher in elderly men with ESR≥15.0 mm/h (248.9±43.5 mg/dl), compared to those with ESR<2.0 mm/h (199.5±31.7 mg/dl, p<0.01). Serum cholesterol concentrations showed no associations with red cell indices but correlated significantly with ESR in elderly men ( r=0.24, p<0.01) and postmenopausal women ( r=0.21, p<0.01). Conclusion: Hypercholesterolemia does not appear to influence MCV but significantly accelerates ESR, especially in elderly men.

Biological and environmental factors affecting ultrasound-induced hemolysis in vitro: 1. HIV macrocytosis (cell size)

This paper reports the results of a further test of the hypothesis that the extent of ultrasound (US)-induced cell lysis in the presence of a US contrast agent to enhance cavitational effects is a function of cell size. The present data support the hypothesis. Human adult erythrocytes in vitro derived from patients with HIV ( n = 15) and apparently healthy individuals ( n = 15) were compared for US-induced hemolysis in vitro. The anticoagulated whole blood from patients with HIV and macrocytic erythrocytes had significantly greater ( p <0.0001) mean corpuscular volume (MCV) and a significantly greater ( p <0.03) extent of US-induced hemolysis in vitro relative to blood from apparently normal, healthy individuals. As a control to determine if disease state ( i.e., HIV infection per se) might be a contributing factor in US-induced hemolysis in vitro, the blood from patients with HIV and apparently normal MCVs ( n = 15) was also tested against an additional population of apparently normal, healthy individuals ( n = 15); there were no statistically significant differences in MCVs or US-induced hemolysis between the two groups ( p >> 0.05). There were also no statistically significant differences in viscosities or hematocrits of the whole blood or plasma in vitro from HIV-macrocytic or apparently healthy individuals but, for all blood types, a pooled correlation existed between hematocrit and whole blood viscosity. (E-mail: Morton_Miller@urmc.rochester.edu)

Haematological Values During Normal Pregnancy in Sprague-Dawley Rats

The present study was undertaken to investigate changes in haematology parameters over the course of gestation in Sprague–Dawley rats. Blood samples were alternatively collected from two groups of pregnant rats on gestational days (GD) 0, 3, 6, 9, 12, 15, 18 and 21 using a needle catheter. Red blood cell counts, haemoglobin and haematocrit on GD 6, 12, 18 and 21 were lower than those of normal non-pregnant rats. These values declined progressively during the course of gestation and reached minimum levels on GD 18 or 21. There were no differences in mean corpuscular volume, mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration between pregnant and non-pregnant rats. Platelet counts in pregnant rats increased gradually with advancing gestation and were much higher on GD 15 and 21 than in nonpregnant rats. Total white blood cell and lymphocyte counts on GD 0–15 were higher than those of non-pregnant rats. These values increased maximally by GD 6 and then decreased progressively to a nadir on GD 21. Neutrophil counts on GD 9–21 were higher than non-pregnant rat values. The neutrophils increased to a peak level on GD 12 and then steadily decreased. These data can be used not only as a historical database for the effective evaluation of data from reproductive toxicology studies, but also as a contribution to biological characterisation of Sprague–Dawley rats.

Congenital Neutropenia: How Low?

To the Editor.— The recent article by Reed and Diehl1shows clearly the difference in mean corpuscular volume (MCV) between white and black volunteer soldiers and notes the historical 7% to 8% incidence of heterozygous α and β-thalassemia in blacks. However, α-thalassemia is by far the most common in blacks, and most cases are α2- (one-deletion) thalassemia. These patients do not have an average MCV in the low seventies, but in the low eighties.2,3This explains the most striking feature in the MCV data provided by Reed and Diehl. There is a skew of the gaussian curve of MCV in the low eighties for black men and women, and not for white ones. Thus, their data in blacks are trimodal: the main peak with a mode of about 90 fL; the skew that probably represents 5% to 6% with α2-thalassemia and a mode of about 82 fL;

Randomized, Placebo-Controlled Trial of Iron Supplementation in Infants With Low Hemoglobin Levels Fed Iron-Fortified Formula

In spite of the declining prevalence of iron-deficiency anemia, a large proportion of low-income infants have "low-normal" (11-11.5 g/dL) and "low" (less than 11 g/dL) hemoglobin (Hgb) values. Because most of these infants are fed iron-fortified formulas, it was of interest whether additional iron supplementation would enhance Hgb values. A cohort of 334 healthy, inner-city, minority, 6-month-old infants, fed iron-fortified formulas, with Hgb values ranging from 9 to 11.5 g/dL, participated in a double-blind, randomized, placebo-controlled trial of supplemental iron at 0, 3, and 6 mg/kg per day for 3 months. Hemoglobin values increased significantly with age, regardless of assignment to placebo or supplemental iron (means for the entire cohort: 6 months 10.9 g/dL, 8 months 11.2, 10 months 11.3, and 12 months 11.4). The proportion of "responders" (Hgb level increased greater than or equal to 1 g/dL) was 34% and did not differ significantly by placebo or iron dose. There were no significant differences in mean corpuscular volume or levels of erythrocyte porphyrins or serum ferritin between treatment groups. The implications of this clinical trial are twofold: (1) screening healthy infants fed iron-fortified formula at the age of 6 months is not justified, regardless of socioeconomic status; (2) the clinical practice of routinely treating low-income, "low-Hgb" infants with iron supplementation, without regard to dietary considerations, is unwarranted.