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P R Gilmer

Publications and source records attributed to P R Gilmer.

16 recordsLinked to original sources
PubMed1988

The "diff-if". Use of microcomputer analysis to triage blood specimens for microscopic examination.

Increasingly, all automated blood counts are not accompanied by a microscopic white blood cell differential. A popular strategy is to obtain a manual differential if any part of the automated blood count and differential is outside specified limits (the "diff-if" strategy). The authors compared two sets of criteria to triage blood counts for manual differentials: previously recommended numeric values, and the analysis of a microcomputer program. In a population of subjects with a high percentage of hematologic disorders, the microcomputer program and the numeric criteria were equally specific (excluding normal blood smears); the program was more sensitive for bands, immature granulocytes, monocytes, nucleated red blood cells, reticulocytosis, teardrops, red blood cell fragments, and hypersegmented neutrophils. The numeric criteria were more sensitive for eosinophilia (less than 1.0 X 10(9)/L) and mandated fewer manual differentials. In a population of predominantly normal subjects, the program was more sensitive for increased bands and equally sensitive for eosinophilia, the only abnormalities observed on the smear. In a population of subjects with predominantly abnormal blood counts, but excluding most primary hematologic disorders, there were few blood smears with abnormalities beyond eosinophilia or increased bands. In both of these groups, the computer program mandated more manual differentials than did the numeric criteria. The authors conclude that microcomputer analysis by the program tested was more sensitive than numeric criteria to identify specimens with abnormal blood smears. Specificity depended on the patient population. The choice of a triage strategy should be based on the individual laboratory's patient population.

Blood↗
PubMed1986

A solution to declining autopsy rates--the Decedent Affairs Office.

Can the decline in autopsy rates be reversed by solving logistical problems that impede or deter permissions and arrangements? The authors report an increase in the autopsy rate at their institution after a Decedent Affairs Office was established. Furthermore, the time between death and autopsy has been greatly narrowed, thus providing optimal tissue for diagnosis. As an additional benefit, the number of organ donations has also risen.

Autopsy↗
PubMed1985

Use of mean platelet volume improves detection of platelet disorders.

Classification of platelet disorders has been based on the platelet count. Addition of a second variable, mean platelet volume (MPV), to the routine blood count allows classification of patients into 9 categories: high, low, or normal MPV, and high, low or normal platelet count. We studied 1,244 adult inpatients. 1,134 had both platelet values normal. 11 patients had high MPV and low platelet count: all had hyperdestructive causes. 15 patients had high MPV and normal platelet count: 12 had heterozygous thalassemia, and three had iron deficiency. Seven patients had high MPV and high platelet count: causes included myeloproliferative disorders, inflammation, iron deficiency, and splenectomy, 25 patients had high platelet counts and normal MPV: the causes were inflammation, infection, sickle cell anemia, iron deficiency, or chronic myelogenous leukemia. 52 patients had an MPV that was inappropriately low for the platelet count (high, normal, or low). All had sepsis, splenomegaly, aplastic anemia, chronic renal failure, or a disease being treated with myelosuppressive drugs. High MPV thus appears correlated with myeloproliferative disease or thalassemia; and low MPV, with cytotoxic drugs or marrow hypoplasia. Addition of MPV to the platelet count allows subtler disorders to be detected (when the platelet count is normal), and allows distinction of the cause of thrombocytopenia.

Blood Cell Count↗
PubMed1983

Improved classification of anemias by MCV and RDW.

New automated blood cell analyzers provide an index of red cell volume distribution width (RDW) or heterogeneity and a histogram display of red cell volume distribution. We have developed a classification of red cell disorders, based on mean corpuscular volume (MCV) or red cell size, heterogeneity, and histograms, to guide diagnosis from the peripheral blood analysis. The distinction of iron deficiency anemia from heterozygous thalassemia or the anemia of chronic disease and the detection of early iron and folate deficiency is improved. Red cell volume distribution histograms identify red cell fragmentation or agglutination, dimorphic populations, and artifactual counting of lymphocytes as red cells. We recommend the use of these new variables in the initial classification of anemia by the practicing physician.

Anemia↗
PubMed1982

Platelet size in health and hematologic disease.

In normal subjects, mean platelet volume (MPV) has an inverse, nonlinear relation with platelet count, while platelet volume heterogeneity has a direct, nonlinear relation with MPV. Compared with the reference range established for normal subjects, patients with chronic lymphocytic leukemia, atherosclerotic heart disease, diabetes mellitus, and chronic undifferentiated schizophrenia had normal platelet volume mean and heterogeneity. Patients treated with cytotoxic chemotherapy for acute nonlymphocytic leukemia, patients with megaloblastic anemia, and patients with aplastic anemia had abnormally small platelets with increased heterogeneity. Patients with chronic myelogenous leukemia had abnormally large platelets with increased heterogeneity.

Anemia, Megaloblastic↗
PubMed1981

Mean platelet volume. The inverse relation of platelet size and count in normal subjects, and an artifact of other particles.

We measured whole-blood mean platelet volume (MPV) and platelet count, determined by the Coulter Counter model S-Plus, in 683 normal subjects. There was nonlinear, inverse relation between MPV and platelet count throughout the normal range of platelet count: the change in MPV was most pronounced at the lower platelet counts. Because of this non-linear relation, "platelet-crit," the product of platelet count and MPV, was not constant, but varied directly with platelet count. Thus, the definition of "normal" values for MPV requires simultaneous reference to platelet count. In the whole blood of 13 patients, non-platelet cell fragments spuriously increased the automated platelet count. Seven patients with erythrocyte fragmentation had spuriously high MPV also: correct MPV and platelet count could be obtained from platelet rich plasma (PRP). In five patients with leukemic blast fragmentation, MPV remained spuriously low and platelet count spuriously high in PRP: only phase count allowed correct count. A patient with megakaryoblastic leukemia had megakaryoblast fragments confused for platelets.

Adolescent↗
PubMed1980

The status of methods of calibration in hematology.

Three years ago, the authors described methods for calibration and quality control of Coulter automated hematology instruments. These and other methods have received fairly widespread use in hematology laboratories. The effectiveness of such use was tested through special questionnaires conducted by the College of American Pathologists in 1978. Current information indicates no clear-cut advantages between fresh whole blood and preserved-cell control materials when properly used for calibration or quality control procedures. Minor but troublesome differences persistently appear between manual or semiautomated methods and in results on fully automated systems. Likewise, daily internal quality control may be monitored by preserved cells or by continuous process control using patient samples. The various systems for calibration and quality control have certain advantages and disadvantages.

Blood Cell Count↗
PubMed1977

Calibration methods for automated hematology instruments.

Recent CAP survey data have documented marked improvement in the reproducibility of hematologic tests. The favorable outcome is attributable largely to the widespread use of automated whole-blood analyzers. Calibration variability, however, detracts from this enhanced precision, and there are clear indications that improvement is necessary. Primary calibration methods for hemoglobin, hematocrit and cell counting procedures are presented. The methods of applying these primary calibration methods to automated whole-blood analyzers are delineated. The use of both preserved reference blood and statistical control technics for the identification of calibration loss is described.

Automation↗
PubMed1977

The prediction of prothrombin time system performance using secondary standards.

A method for the comparison of prothrombin time systems using single large lots of lyophilized plasma in the College of American Pathologists Surveys is presented. Systematic biases for prothrombin time methods as well as for thromboplastins have been measured, and their use allows a very accurate (within 2.25%) prediction of the prothrombin time for the great number of prothrombin time systems presently being used in the United States.

Blood↗
PubMed1976

The reticulocyte. An approach to definition.

Experiences of the CAP Survey Program in reticulocyte counts and morphologic identification of reticulocytes from 1971 to 1974 are reviewed. Problems of morphologic identification are reflected in an excessive variance of reticulocyte counts. Statistical sources of variations in counting are identified. The older, original descriptions and definitions of morphologic criteria are reviewed and discussed in relationship to Survey performance.

Analysis of Variance↗
PubMed1975

Studies of fibrinogen measurement in the CAP survey program.

A review of the College of American Pathologists' Surveys experience in fibrinogen testing from 1967 to 1974 is reported. Trends in fibrinogen methodology and the emergence of a consensus choice of the modified thrombin time method are documented. The reasons for these changes from former methods are discussed.

Biuret Reaction↗