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Biomedical subjects

P M Starkey

Publications and source records attributed to P M Starkey.

13 recordsLinked to original sources
PubMed1992

Tumor necrosis factor-alpha selectively stimulates prostaglandin F2 alpha production by macrophages in human term decidua.

OBJECTIVE: Our objective was to investigate the effect of tumor necrosis factor-alpha on prostaglandin production by human term decidual cell subtypes in vitro. STUDY DESIGN: We measured the effect of tumor necrosis factor-alpha on prostaglandins F2 alpha, E2, D2, F metabolite, and E metabolite production by decidual cells (n = 4) with radioimmunoassay. We used flow cytometry after labeling with an antibody to histocompatibility antigen DR, L243, which is specific for macrophages in this tissue, to prepare pure populations of decidual macrophages (n = 3). Differences in prostaglandin output were analyzed by Wilcoxon and Kruskal-Wallis tests. RESULTS: Tumor necrosis factor-alpha stimulated prostaglandin F2 alpha output by unfractionated decidual cells, without altering the output of any other prostaglandins. Tumor necrosis factor-alpha (10 nmol/L) increased prostaglandin F2 alpha production from decidual macrophages (HLA-DR-positive cells) by about threefold: from a median of 727 (range 423 to 1226) to a median of 1974 (range of 1550 to 2201), fmol/10(6) cells per 18 hours, as compared with a 1.4-fold increase from nonmacrophages from a median of 247 fmol/10(6) cells per 18 hours (range 125 to 611) to a median of 340 fmol/10(6) cells per 18 hours (range 201 to 505). CONCLUSION: Stimulation of decidual prostaglandin F2 alpha production by tumor necrosis factor-alpha may be important in the etiology of spontaneous labor at term or preterm labor associated with infection.

Adult↗
PubMed1992

Isolation and purification of human endometrial stromal and glandular cells using immunomagnetic microspheres.

Isolation of pure preparations of the different cell populations of human endometrium is a prerequisite for studies of in-vitro function. Sieving of dispersed endometrial cells, followed by adsorption onto immunomagnetic microspheres coated with antibody to Thy-1 was used to separate glandular and stromal cells. The purity of these cell populations was checked with antibodies to cytokeratin and Thy-1. The stromal cells were 98% pure and 90% viable, gland cells were 82% pure with 76% viability. The purified cells were able to proliferate in vitro as shown by thymidine incorporation.

Antigens, Surface↗
PubMed1992

Production of granulocyte colony-stimulating factor at the materno-foetal interface in human pregnancy.

A bioassay specific for human granulocyte colony-stimulating factor (G-CSF) was developed and used to measure G-CSF production in human pregnancy tissues. G-CSF was secreted by both foetal chorionic villous and maternal decidual tissues taken in the first trimester and at term. The level of G-CSF production by placental tissue was 6750 (1250-10,000) units of bioactivity per g of tissue in 48 hr in the first trimester and 104 (83-190) U/g at term. Bioactive G-CSF was also secreted by decidual tissue, more in the first trimester than at term. ELISA immunoassays measured 75 (10-820) ng/g/48 hr of G-CSF antigen from first trimester placenta, 15 (10-50) ng/g from first trimester decidua and less than 2 ng/g from term placenta. RNA isolated from decidual and chorionic villous tissue or from cells purified by flow cytometry, contained G-CSF mRNA in both tissues. In decidua, mRNA for G-CSF was confined to the macrophages, and cytotrophoblast from term amniochorion contained no detectable G-CSF mRNA. No G-CSF, measured as bioactivity or as mRNA, was detectable in choriocarcinoma cell lines.

Biological Assay↗
PubMed1992

Prostaglandin D2 production by term human decidua: cellular origins defined using flow cytometry.

OBJECTIVE: To measure prostaglandin (PG) D2 output by human decidua at term and to identify the cell population(s) responsible for its production. METHODS: Decidual cell suspensions were prepared enzymatically and the cells were labeled with either of two monoclonal antibodies: F10/89/4, which recognizes the leukocyte common antigen (CD45), or L243, which labels HLA-DR and is specific for macrophages in this tissue. Cells were sorted on a Coulter EPICS 541 flow cytometer. Prostaglandin levels were measured by radioimmunoassay. RESULTS: Human decidua is an important intrauterine source of PGD2 at term. Twenty-nine percent (median) of decidual cells were CD45-positive and 12% were HLA-DR-positive; sorted cell populations were 95% pure. Prostaglandin D2 output (fmol/10(6) cells per 3 hours) by bone marrow-derived (CD45-positive) cells was significantly higher than that by non-bone marrow-derived cells: median 63 (range 35-67) versus 20 (13-21), respectively; HLA-DR-positive cells (macrophages) had the highest PGD2 production rate (186, range 97-288 fmol/10(6) cells per 3 hours). Under basal conditions, PGD2 production by unsorted term decidual cells was not influenced by labor. CONCLUSION: Bone marrow-derived cells (macrophages) are the major source of decidual PGD2 at term. Further studies are required to investigate the possible role of PG production by human decidual macrophages in the mechanism of term and/or preterm labor.

Cell Separation↗
PubMed1991

Variation during the menstrual cycle of immune cell populations in human endometrium.

Morphometric analysis and immunohistology of tissue sections have been used to assess variation, during the normal menstrual cycle, of the bone marrow-derived cell populations in human endometrium. Levels of T cells and macrophages were found to be relatively constant throughout the cycle. In contrast, numbers of large granular lymphocytes, identified as being CD56-positive, were generally low between days 10 and 19, but increased sharply in the latter part of the luteal phase, decreasing again after menstruation. This LGL population is known to be abundant in first trimester pregnancy decidua, and is presumed to play a role in early pregnancy success.

Antigens, CD↗
PubMed1991

Expression of intermediate filament in endometrial glands changes with the onset of pregnancy and in endometriosis.

Appropriate endometrial differentiation is believed to be a prerequisite for pregnancy success. This study investigates the expression of two intermediate filament proteins, cytokeratin and vimentin, in human endometrium and first trimester decidua and in ectopic endometrium from women with endometriosis. Stromal elements, including vascular endothelial cells, were consistently vimentin-positive and cytokeratin-negative. Surface and glandular epithelial cells of human endometrium co-expressed vimentin and cytokeratin during all stages of the menstrual cycle, but failed to express vimentin after the onset of pregnancy. This suggests that intermediate filaments, and especially vimentin, may have a role to play in the proliferation and/or differentiation of the endometrial glands during decidualization. Ectopic endometrium showed a staining pattern similar to normal endometrium.

Decidua↗
PubMed1990

Cell populations in the human early pregnancy decidua: natural killer activity and response to interleukin-2 of CD56-positive large granular lymphocytes.

Large granular lymphocytes (LGL) have been shown previously to be the most abundant cell type in the first trimester human decidua. Purified populations of decidual LGL were prepared by flow cytometry of cell dispersions labelled with NKH1 (CD56), an antibody specific for peripheral blood LGL, and the functional properties of CD56-positive cells, CD56-negative and unsorted decidual cells compared. Both CD56-positive cells and unsorted decidual cells have cytotoxic activity against the natural killer (NK) cell target K562 which was weak compared with that of peripheral blood mononuclear cells (PBMC). The CD56-negative cells had no cytotoxic activity against K562. All three decidual cell populations proliferated in response to recombinant human interleukin-2 (rIL-2), but none produced detectable levels of IL-2 in culture. When unsorted decidual cells were cultured for 7 days in rIL-2 the proportion of CD56-positive cells increased and NK activity against K562 was augmented. The NK activity of purified CD56-positive decidual cells was also augmented by culturing in rIL-2. The potential role of decidual LGL in regulating the development of the semi-allogeneic placenta is discussed.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1977

The degradation of articular collagen by neutrophil proteinases.

The action of the serine proteinase (EC 3.4.21--)of human neutrophil leucocytes, elastase and cathepsin G, on cartilage and tendon was investigated. With cartilage, both enzymes first degraded the proteoglycan, then solubilized collagen by an attack on the terminal peptides, destroying the inter- and intramolecular cross-links. There was little degradation of the helical region of the type II collagen. Elastase also solubilized type I collagen from tendon, though this was less susceptible than cartilage collagen, and attacked the terminal peptides and perhaps the helical region of type I skin collagen in solution. Cathepsin G had little or no effect on type I collagen of skin or tendon. Since massive infiltration of joint tissues by neutrophil leucocytes is a prominent feature of inflammatory joint disease, it may well be that elastase and cathepsin G make a significant contribution to the tissue damage that occurs.

Achilles Tendon↗
PubMed1977

The effect of human neutrophil elastase and cathepsin G on the collagen of cartilage, tendon, and cornea.

The degradation of collagen in a number of inflammatory diseases is associated with infiltration of the tissues by neutrophil leucocytes. The neutrophil serine proteinases, elastase and cathepsin G, solubilize type II collagen from articular cartilage by an attack on the terminal peptides, destroying the inter- and intra-molecular crosslinks. Both enzymes also solubilize type IV collagen from kidney basement membrane. Elastase attacks the terminal peptides of type I collagen of tendon, cornea and skin, and also attacks the helical region of type I skin collagen. It seems probable that the neutrophil proteinases play an important role in collagen degradation in vivo in a variety of pathological conditions.

Animals↗
PubMed1976

Neutral proteinases of human spleen. Purification and criteria for homogeneity of elastase and cathepsin G.

1. Human spleen was found to contain proteinases active against azo-casein at neutral and alkaline pH values. 2. The activity was stimulated by high ionic strength and some detergents. 3. Optimal extraction of the proteinases from the tissue was achieved with 1.0M-NaCl containing 0.1% Brij 35 and 0.1% trisodium EDTA. 4. The proteinases were efficiently adsorbed to insoluble material in the absence of salt in the initial stages of purification. 5. Two distinct proteinases were separated by chromatography on DEAE-cellulose, an elastase and a chymotrypsin-like enzyme designated cathepsin G. 6. Both enzymes were highly purified by further column chromatography. 7. The molecular weights of the enzymes were estimated by gel chromatography and sodium dodecyl sulphate-gel electrophoresis. 8. It was shown by isoelectric focusing and gel electrophoresis that both enzymes are cationic proteins that occur in multiple forms.

Cathepsins↗
PubMed1976

Human lysosomal elastase. Catalytic and immunological properties.

1. The elastase of human spleen was shown to exhibit endopeptidase activity against azo-casein and elastin. 2. Activity against several synthetic substrates was detected, and benzyloxycarbonyl-L-alanine 2-naphthyl ester was found to be a good substrate for routine use. 3. The enzyme showed a broad pH optimum in the range of 8.2-9.2 against azo-casein and the synthetic substrate. 4. The effect of inhibitors on the spleen elastase showed it to be a serine proteinase with a specificity similar to that of porcine pancreatic elastase. 5. Specific antisera were raised against the enzyme, and it was shown to be immunologically identical with the lysosomal elastase of human neutrophil leucocytes.

Caseins↗
PubMed1976

Human cathepsin G. Catalytic and immunological properties.

1. The specificity of cathepsin G, a neutral proteinase from human spleen, was examined by use of low-molecular-weight substrates. The enzyme was found to hydrolyse several synthetic substrates also hydrolysed by chymotrypsin, but with different kinetic constants. 2. Maximal activity against benzoyl-DL-phenylalanine 2-naphthol ester and azo-casein was in the range pH 7.5-8.0. 3. The sensitivity of cathepsin G to the action of potential inhibitors was determined, and compared with those of bovine chymotrypsin and subtilisin. Cathepsin G showed the characteristics of a serine proteinase, but was less affected by the chloromethyl ketone of tosylphenylalanine than was chymotrypsin. 4. A rabbit anti-(human cathepsin G) serum was raised, and precipitin lines formed in agarose gel were stained for activity of the enzyme. 5. Cathepsin G was shown to be immunologically identical with the chymotrypsin-like enzyme of the azurophil granules of the neutrophil granulocytes.

Cathepsins↗