Search PubMed⌕ Search

Biomedical subjects

P C Stone

Publications and source records attributed to P C Stone.

26 records · Page 2Linked to original sources
PubMed1983

Quantitative cytochemistry of the toxic granulation blood neutrophil.

A quantitative cytochemical study has been made, using scanning-integrating microdensitometry, of 1000 toxic granulation blood neutrophils from 20 infected patients, in comparison with 1250 normal blood neutrophils. Myeloid precursor cells in 10 normal marrows were also studied. Normal bone marrow granulocyte maturation was associated with a progressive decrease in azurophilic granule enzymes (myeloperoxidase, beta-glucuronidase, acid phosphatase, chloroacetate esterase), and also Alcian blue staining from acid mucosubstance, but an increase in the specific granule marker lactoferrin. Toxic granulation blood neutrophils showed minor changes in the enzyme content of their azurophilic and specific granules, consistent with cell immaturity, and an increase in acid mucosubstance in azurophilic granules. Abnormal maturation of azurophilic granules, with persistence of acid mucosubstance, is the likely explanation for the intense Romanowsky dye staining of the toxic granulation neutrophil.

Acute Disease↗
PubMed1983

Quantitative cytochemistry of blood neutrophils in acute myeloid leukaemia.

Blood neutrophils were studied by quantitative cytochemistry in patients with acute myeloid leukemia at diagnosis (17 patients), during remission (17 patients) and in relapse (seven patients). Scanning and integrating microdensitometry was used to quantify components of azurophilic granules (myeloperoxidase, chloroacetate esterase, beta-glucuronidase, acid phosphatase, acid mucosubstance) and also specific granules (lactoferrin). At diagnosis, neutrophil myeloperoxidase, chloroacetate esterase, and lactoferrin were significantly decreased, compared with normal neutrophils from 25 controls, with 13 of the 17 patients showing a partial or complete deficiency of at least one granule constituent. Five of seven patients, followed serially from remission into relapse, showed a fall in activity of azurophilic or specific granule components before overt blast cell infiltration of the marrow had occurred and this may predict relapse.

Acid Phosphatase↗
PubMed1983

An improved chromogenic substrate endotoxin assay for clinical use.

An improved quantitative assay for endotoxin in plasma was developed after evaluating three different chromogenic substrates and seven methods for removal of plasma inhibitors. Optimal storage conditions for plasma samples prior to assay were also determined. Using chromogenic substrate S2423 with plasma diluted 1/10 in water and heated to 75 degrees C for 5 min to remove inhibitors, a within-batch coefficient of variation of 4% was obtained at levels of endotoxin likely to be encountered clinically. The limit of assay sensitivity was less than 10 pg/ml. This assay provides a sensitive quantitative test for single episodes of endotoxaemia in individual patients but variable activation of the Limulus proenzyme by endotoxin from different bacterial strains limits quantitative comparisons between patients.

Blood Preservation↗
PubMed1982

Variant cell lines from the human promyelocyte line HL60.

The continuous human promyeloid cell line HL60 may be induced to differentiate into neutrophils by the presence of 1.25% dimethylsulphoxide (DMSO) and related compounds [4]. When treated with 12-O-tetradecanoylphorbol-13-acetate (TPA), the cells exhibit may features characteristic of monocytes/macrophages [13]. In both cases, the induced HL60 cells lose their proliferative ability. The availability of this inducible cell line has led to an increasing number of studies aimed at dissecting the process of myeloid differentiation. However, the correct interpretation of such studies may only be reached through the use of appropriate cellular controls; specifically, variant HL60 cell lines which do not differentiate in response to the inducing agents. Here we report the isolation and characterization of two variant cell lines of HL60 which do not differentiate in the presence of 1.25% dimethylsulphoxide but still respond to TPA. Comparison of these HL60 variants with the parental line should facilitate the elucidation of molecular events which regulate myeloid differentiation.

Cell Division↗
PubMed1982

Serum levels of acute phase and cardiac proteins after myocardial infarction, surgery, and infection.

C-reactive protein and four other acute phase reactant proteins of non-cardiac, origin (orosomucoid, alpha 1- antitrypsin, heptoglobin, and alpha 2- macroglobulin) were studied serially by laser immunonephelometric assay in sera from 17 patients with myocardial infarction. A similar comparison was made in 57 patients undergoing surgery and 72 patients with acute infection. C-reactive protein was consistently the most sensitive acute phase reactant in all three conditions. After myocardial infarction, a raised serum C-reactive protein level was found on admission in four patients before a rise in creatine kinase MB isoenzyme (CK MB). The peak C-reactive protein level was reached on the third post-infarct day and it then declined over seven days with a half-life similar to myocardial tropomyosin. Serial monitoring of serum C-reactive protein, in parallel with cardiac proteins of short half-life (CK MB) and long half-life (tropomyosin), provides maximal information for diagnosis and for detecting post-infarct complications.

Alpha-Globulins↗
PubMed1982

Studies of human myeloid antigens using monoclonal antibodies and variant lines from the promyeloid cell line HL60.

Monoclonal antibodies were produced using mice immunized with the human promyeloid cell line HL60. Two antibodies are described which identify antigens selectively expressed by myeloid cells. Studies using normal bone marrow and myeloid leukaemia cells demonstrated that one of these antibodies (AGF4.48) identifies an antigen expressed throughout the promyeloid to neutrophil stages of maturation. In contrast, the second antibody (AGF4.36) identifies an antigen expressed at the promyeloid to metamyeloid stages and is absent from most blood neutrophils. The HL60 line can be induced to differentiate into neutrophils by 1 . 25% dimethylsulphoxide (DMSO) (Collins et al., 1978). Variant lines from HL60, unresponsive to 1 . 25% DMSO, lack the 'transient' myeloid antigen (AGF4.36) and show a reduced expression of the myeloid antigen (AGF4.48). The variant lines can be induced to mature using higher DMSO concentrations (1 . 5-1 . 75%) and do not express the 'transient' antigen (AGF4.36) during their maturation. The use of these lines in studies of myelopoiesis is discussed.

Animals↗
PubMed1976

Response of crickets to amount of forage in the diet.

Three replicated tests were to define the conditions needed to use house crickets (Acheta domesticus) to evaluate forages. Crickets were placed on various proportion of forage-to-concentrate mixtures to determine the relative proportions best suited for cricket survival, growth, and maturity. The concentrate portion alone was adequate to support nominal cricket performance. Forages used were timothy, alfalfa, and alfalfatimothy (1:1). Forages replaced from 0 to 100%, in increments of 10% of the concentrate portion. A diet of 40% concentrate and 60% roughage was suitable for evaluating growth and survival effects. The 28-day tests were not long enough to evaluate fully the effects of diet on maturity.

Animal Feed↗