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R W Kelly

Publications and source records attributed to R W Kelly.

At least 73 records · Page 4Linked to original sources
PubMed1994

The immunosuppressive contribution of prostaglandin components of human semen and their ability to elevate cyclic adenosine monophosphate levels in peripheral blood mononuclear cells.

We have compared the ability of fractions from seminal plasma to suppress lymphocyte proliferation and examined the effects of these fractions in raising intracellular cyclic adenosine monophosphate (cAMP) in the same preparations of peripheral blood mononuclear cells. Human seminal plasma is very effective at raising cAMP but seminal plasma stripped by C-18 reverse phase columns is inactive. Both prostaglandin E (PGE) and 19-hydroxy PGE contribute to the elevation of cAMP and a combination of these two prostaglandins is as effective as whole seminal plasma in raising cAMP but not as effective in inhibiting lymphoproliferation. These results suggest that human seminal plasma prostaglandins act through the EP2 receptor to inhibit T cell and NK cell function and thus attenuate both the cellular and humoral actions of the female's immune system.

Cyclic AMP↗
PubMed1994

Prostaglandin inactivation is increased in endometrium after exposure to clomiphene.

Prostaglandin (PG) dehydrogenase inactivates PGs by oxidising the 15-hydroxyl group and thus plays a key role in controlling their effective local concentrations. This enzyme is thought to be under the control of steroid hormones and is found in human endometrium at high levels in the secretory phase of the menstrual cycle but is absent during the proliferative phase. We have examined the PG dehydrogenase activity in human endometrium from women who had been treated with the anti-oestrogen clomiphene at an earlier stage of the cycle and found high levels of the enzyme in the proliferative phase. This data was supported by the culture of endometrium from clomiphene treated women which showed both high PG production and extensive inactivation comparable to that seen in the secretory phase. This effect of clomiphene on the PG inactivating ability of endometrium could be of clinical use in management of disorders where elevated PGs are present.

Adult↗
PubMed1994

Expression of a common secretory granule specific protein as a marker for the extracellular organelles (prostasomes) in human semen.

OBJECTIVE: To further characterize prostasomes, trilamellar to multilamellar vesicles that are thought to originate from acinar cells of the human prostate and present in appreciable amounts in normal human semen. Purified prostasomes were shown to have immunosuppressive activity in vitro as measured by inhibition of mitogen-induced lymphocyte proliferation and inhibition of superoxide generation by neutrophils. A granule membrane protein, called granulophysin, has recently been identified in the membranes of platelet dense granules. Antibodies that recognize granulophysin also stain granules in different cell types including leukocytes, melanocytes, neurones, endothelial cells, and epithelial cells. DESIGN: The presence of epitopes recognized by antigranulophysin monoclonal antibody in prostasomes was investigated using indirect immunofluorescence and subsequent cytofluorimetric analysis. The protein was also analyzed by Western blotting. Reactivity of antigranulophysin antibody with the prostate tissue was studied by immunoperoxidase staining. RESULTS: A majority of prostasome particles specifically reacted with antigranulophysin antibody. In lysates prepared from prostasomes, a broad band of 32 to 37 kd was detected by Western blotting. CONCLUSION: This report defines granulophysin as a constituent membrane molecule of prostasomes that may serve as a useful marker in elucidation of prostasome function.

Antigens, CD↗
PubMed1994

Progesterone control of interleukin-8 production in endometrium and chorio-decidual cells underlines the role of the neutrophil in menstruation and parturition.

Interleukin-8 (IL-8) attracts neutrophils into tissues and causes them to degranulate. Both menstruation and parturition involve neutrophil migration into uterine tissues and therefore IL-8 is a likely mediator of the tissue re-arrangements that accompany these events. We have examined the ability of endometrium explants and chorion cells in culture to synthesize and release IL-8 and the ability of progesterone, a synthetic progestin [medroxyprogesterone acetate (MPA)] and dexamethasone to inhibit this production. In endometrium, the stage of the menstrual cycle did not affect IL-8 production but a 10(-6) M concentration of progesterone or dexamethasone significantly reduced the concentration of IL-8 in medium after 24 h. After a further 24 h with lipopolysaccharide (LPS) stimulation, only MPA and dexamethasone inhibited production significantly. In chorion cells, IL-8 production was significantly decreased by both MPA and dexamethasone in the LPS stimulated cells but the reduction in the first 24 h was not significant. The IL-8 produced in uterine tissues might act synergistically with prostaglandin E (PGE), a likely site for this interaction being blood vessels where PGE production is also repressed by progesterone. Such a cooperative action would maintain low leukocyte entry into uterine tissues in the presence of progesterone and falling steroid levels would induce leukocyte immigration and activation with consequent tissue destruction. Such steroid-dependent interactions are important in our understanding of the mechanisms of menstruation and parturition and could allow new approaches to the treatment of uterine pathology.

Cells, Cultured↗
PubMed1994

Perivascular location of a chemokine interleukin-8 in human endometrium: a preliminary report.

The cytokine interleukin-8 (IL-8) is capable of inducing selective neutrophil chemotaxis and activation and has been postulated as the signal for neutrophil recruitment and activation in reproductive tissues. The aim of this study was to examine the localization of IL-8 in non-pregnant human endometrium in view of its potential as a local modulator of endometrial function. Endometrial biopsies (proliferative, n = 8; secretory, n = 7) from 15 subjects were available for immunolocalization of IL-8. Primary antibody (rabbit polyclonal against IL-8) application was followed by either a horseradish peroxidase streptavidin detection system (proliferative, n = 5; secretory, n = 4) or an avidin-biotin alkaline phosphatase detection method (proliferative, n = 3; secretory, n = 3). All endometrial biopsies showed heterogeneous positive staining for IL-8 in association with blood vessels in both proliferative and secretory phase biopsies. The immunostaining was apparently not associated with endothelial cells but rather appeared to be associated with the smooth muscle layer of arterioles. Secretory phase biopsies exhibited immunoreactivity in association with small blood vessels and spiral arterioles. The perivascular location of IL-8 throughout the stages of the human menstrual cycle is consistent with its proposed biological role as a modulator of endometrial function, especially synergism with prostaglandin E and the transmigration of leukocytes.

Adult↗
PubMed1993

Interleukin-8 production by the human cervix.

OBJECTIVES: Our purpose was (1) to determine whether the human cervix is capable of producing interleukin-8 in vitro and to examine the possibility of stimulating an increase in any such output and (2) to examine the concomitant production of prostaglandins. STUDY DESIGN: Cervical tissue was obtained from 48 women, 29 pregnant women undergoing surgical termination of pregnancy (20 of whom were treated with the prostaglandin analog Cervagem), 14 nonpregnant, premenopausal women, and three postmenopausal women. Explants were cultured and the medium was assayed for interleukin-8 and prostaglandin E2. Analysis of variance and Newman-Keuls statistical tests were used. RESULTS: Significant quantities of interleukin-8 were produced by the tissue, and the data indicate that cervical explants from pregnant and nonpregnant women behave in a similar way when challenged by phorbol myristate acetate but that the postmenopausal cervix loses its capacity for interleukin-8 production. CONCLUSIONS: Human cervix is capable of producing large amounts of interleukin-8 in vitro, and it may be influenced by the steroid hormones. Thus interleukin-8 could be an excellent candidate for a prime role in neutrophil-mediated cervical ripening.

Abortifacient Agents, Nonsteroidal↗
PubMed1993

Correlation between umbilical artery resistance index, 6 ketoprostaglandin F1 alpha and thromboxane B2 in the fetoplacental compartment in patients with pregnancy induced hypertension.

Umbilical artery flow velocity waveforms (UAFVW's) were measured by Doppler ultrasound in 35 pregnant women with pregnancy induced hypertension. The stable hydration products of the vasoconstrictor and proaggregatory thromboxane A2 and vasodilatory and anti-aggregatory prostacyclin (i.e. thromboxane B2 (TxB2) and 6 ketoprostaglandin F1 alpha (6 keto PGF1 alpha) respectively) were measured in blood obtained from the umbilical vein and were assayed by radioimmunoassay. Abnormal umbilical artery Resistance Index (UARI) was associated with higher thromboxane B2 levels, lower 6-ketoprostaglandin F1 alpha levels and lower 6-keto PGF1 alpha/TxB2 ratio. Moreover, the umbilical artery Resistance Index was significantly correlated with the 6-keto PGF1 alpha/thromboxane B2 ratio suggesting an association between abnormal umbilical artery blood flow and altered prostacyclin/thromboxane balance in the fetoplacental compartment in patients with pregnancy induced hypertension (PIH).

6-Ketoprostaglandin F1 alpha↗
PubMed1993

The effects of mifepristone (RU486) on prostaglandin dehydrogenase in decidual and chorionic tissue in early pregnancy.

Prostaglandin dehydrogenase is the main inactivating enzyme for prostaglandins and therefore controls local levels of prostaglandins. Since there is some evidence that the expression of this enzyme is under progesterone control it is reasonable that one of the effects of antiprogestin is to reduce the concentration of this enzyme and thus increase the effective concentration of prostaglandin within tissue. We have investigated the amount of enzyme activity within decidua and chorionic villi from women receiving the antigestagen mifepristone (RU486) 12, 24 and 36 h prior to surgical abortion, and examined the effect on tissue concentrations of prostaglandin dehydrogenase. Women receiving mifepristone in all groups had a significant reduction in concentration of prostaglandin dehydrogenase enzyme in decidual tissue. There was also a marked reduction in prostaglandin dehydrogenase in decidual cells following RU486, as demonstrated by immunochemical methods. At this stage of pregnancy, prostaglandin dehydrogenase was present in abundance in cytotrophoblast cells of chorionic villi but virtually absent from syncytiotrophoblast. In chorionic villi after RU486 administration in vivo, there were no obvious differences in prostaglandin dehydrogenase distribution or reactivity in the majority of cases.

Abortion, Induced↗
PubMed1993

Plasma prostaglandin metabolite concentrations in normal and dysfunctional labour.

OBJECTIVE: To determine the concentrations of the metabolites of prostaglandin E2 (PGEM) and of prostaglandin F2 alpha (PGFM) prior to the onset of labour and during spontaneous labour, and to correlate the changes in concentrations of these metabolites with labour outcome. DESIGN: Longitudinal study throughout labour. SETTING: Labour ward of a large maternity unit. SUBJECTS: Seven primigravid and 11 parous women in the late third trimester with no signs of labour, and 17 primigravid and 11 parous women in spontaneous labour. INTERVENTIONS: Six of the primigravid women required augmentation with oxytocin because of dysfunctional labour. RESULTS: Before labour, parous women had significantly higher concentrations of both PGEM (P < 0.007) and PGFM (P < 0.006) compared with primigravid women. During labour, PGFM concentrations were significantly higher in both primigravid (P < 0.0002) and parous (P < 0.0001) women compared with the concentrations of these metabolites in women not in labour; the same was true for PGEM in primigravid (P < 0.003) but not in parous (P = 0.1) women. There was a small but significant increase (P < 0.02) in PGEM as labour progressed in both the normal groups. Amniotomy was associated with a significant increase in PGFM in primigravid and parous women (P < 0.002 and P < 0.009, respectively). The concentration of PGFM one hour following amniotomy correlated inversely with the amniotomy to delivery interval in both the normal primigravid (r = -0.624; P = 0.04) and the parous (r = 0.745; P = 0.021) groups. Women with dysfunctional labour showed no significant rise in PGEM or PGFM. Their PGFM concentrations were significantly lower than those seen in normal labour (P < 0.05). The concentration of PGFM in cord blood was significantly higher (P < 0.0001) in the parous women who laboured than in women delivered by elective caesarean section. There was no difference in the corresponding concentrations of PGEM (P = 0.9). CONCLUSIONS: These data show that spontaneous labour is associated with increased concentrations of prostaglandin metabolites in the maternal plasma, and are consistent with PGF2 alpha being an important stimulator of uterine contractility, with a relative deficiency of PGF2 alpha being associated with dysfunctional labour.

Adult↗
PubMed1993

The effect of mifepristone (RU486) on the immunohistochemical distribution of prostaglandin E and its metabolite in decidual and chorionic tissue in early pregnancy.

The widespread tissue distribution of prostaglandin dehydrogenase (PGDH), the main enzyme for the metabolism and deactivation of prostaglandin (PG), suggests that local effective levels of PG are controlled by catabolism. Previous reports have suggested that after the administration of mifepristone (RU486) in vivo, the levels of PGDH in uterine tissues fall, such results support earlier suggestions that PGDH is under progesterone control in reproductive tissues. In this study we have used immunohistochemistry to assess tissue concentrations of PGE and its main metabolite 13,14-dihydro-15-keto-PGE in chorionic villi and decidua from women treated with RU486 12, 24, and 36 h previously. In control villous tissue, PGE and 13,14-dihydro-15-keto-PGE2 (PGEM) are prominent in the syncytiotrophoblastic layer, whereas PGE stains only weakly in cytotrophoblasts, due to the presence of PGDH in this region; treatment with RU486 in vivo causes little change in distribution or intensity in villi. However, in decidua, staining for PGE2 was intense in the glands after RU486 and localized in the supranuclear region of the cells. Small blood vessels that were PGE negative and PGEM positive in the controls were PGE positive and PGEM negative in treated tissue. These findings show that PG stimulation by antiprogestin is by means of a direct effect on PGDH, and secondly, that the prominent rise in PGE in blood vessels may be a major mode of action of this steroid in causing abortion, as PGs may synergize with leukocyte chemotactic agents to stimulate neutrophil ingress and tissue destruction.

Chorionic Villi↗
PubMed1992

Choriodecidual production of interleukin-8 and mechanism of parturition.

Both prostaglandins and antiprogestagens can induce labour and ripen the cervix, but the mechanisms are unclear. The collagenases that bring about cervical ripening are neutrophil derived. We examined the potential of uterine tissues to control neutrophil attraction by measuring interleukin-8 production. Choriodecidual cells in culture produced substantial amounts of interleukin-8; release was inhibited by progesterone and stimulated by the antiprogestagen mifepristone. Interleukin-8 production was similar in cells from spontaneously delivered placentas and from those obtained at caesarean section. Since prostaglandin E and interleukin-8 have synergistic effects, we suggest that interleukin-8 activity is the final common step of prostaglandin and antiprogestagen action in parturition.

Cells, Cultured↗
PubMed1992

Relative immunosuppressive activity of human seminal prostaglandins.

Human seminal plasma contains uniquely high concentrations of prostaglandins of the E series which are believed to contribute to its immunosuppressive effects in vivo. In order to obtain further insight into their activity we have compared the immunosuppressive properties in vitro of PGE1, PGE2 and 19-OH PGE using three immunological systems known to be modulated by prostaglandins, namely, mitogen induced lymphocyte proliferation, IL-2 and transferrin receptor expression and NK-cell mediated cytotoxicity. These studies revealed that PGE1 and PGE2 exerted a greater immunosuppressive effect than 19-OH PGE, but considerably higher levels of 19-OH PGE in semen might contribute the majority of immunosuppressive activity in vivo. Our studies also show that the lower stability of 19-OH PGE in culture media may be responsible for its lower immunosuppressive effect observed in vitro.

Alprostadil↗
PubMed1992

The measurement of the main PGE metabolite, 13,14-dihydro-15-keto prostaglandin E by radioimmunoassay using methyl oxime stabilization.

The measurement of 13,14-dihydro-15-keto prostaglandin E2 [PGEM] is complicated by the artefactual formation of compounds of the corresponding A series which are reactive towards protein. Existing methods of assay depend on the deliberate dehydration to the 'A' form followed by cyclization in alkaline solution to a bicyclic derivative which is stable and can be measured by radioimmunoassay. We report an alternative approach using methyl oximation of the 9- and 15-keto groups which confer stability on the molecule. This derivatization is simple and does not involve an active intermediate such as those of the PGA series. The antiserum for radioimmunoassay is raised against the methyl oxime form. The label is the methyl oxime of PGEM coupled to a tripeptide Pro-gly-tyr through the nitrogen in the proline ring. This is a linkage distinct from that used to raise the antiserum and thus is not preferentially recognized over the endogenous analyte; this results in a high sensitivity assay. The results correlated well with those from the bicyclic assay when both assays were used to measure the same samples of peripheral blood from women receiving a sustained release PGE pessary for ripening the cervix. The technique provides a rapid and reliable method for determining prostaglandin E metabolites.

Alprostadil↗
PubMed1992

The effect of pH on release of PGE2 from vaginal and endocervical preparations for induction of labour: an in-vitro study.

OBJECTIVE: To study the effect of pH and precoating with obstetric cream on the release of prostaglandin E2 (PGE2) from commercially available triacetin and starch based gels, lactose based vaginal tablets and sustained release hydrogel polymer pessaries in-vitro. DESIGN: A prospective observational study. METHODS: PGE2 preparations held in dialysis bags were placed in Ringers lactate buffer and release of PGE2 into the buffer was measured over 8-12 h by radioimmunoassay. The hydrogel polymer pessary was also assessed after precoating with obstetric cream. MAIN OUTCOME MEASURES: In-vitro PGE2 release at pH 7.4, pH 5.4 and pH 3.4. RESULTS The gel preparations provided rapid and reliable release, while the lactose based vaginal tablet provided much lower release of PGE2 with sudden and variable release occurring after 5-8 h, an effect which was enhanced at low pH. With the triacetin gel preparation, release of PGE2 was reduced at lower pH, while the starch based gel appeared to provide optimal release at pH 5.4. The hydrogel polymer pessaries provided linear release in-vitro and this was reduced at pH 3.4. In addition, precoating the sustained release hydrogel polymer pessaries with obstetric cream virtually abolished release of PGE2. CONCLUSIONS: As the vagina is normally acid, these results suggest that vaginal pH could influence PGE2 release and this may result in variable clinical responses. In view of this, pH should be taken into account in the development of preparations for clinical use. Furthermore, the use of obstetric cream should be avoided when administering PGE2 preparations for induction of labour.

Cells↗
PubMed1992

Immunosuppression by human seminal plasma--extracellular organelles (prostasomes) modulate activity of phagocytic cells.

PROBLEM: Prostasomes are trilamellar to multilamellar vesicles produced by the acinar cells of the human prostate and are present in appreciable amounts in normal human semen. The aim of this work was to study the effect of prostasomes on human polymorphonuclear cell and monocyte function. METHODS: Functional activity of human neutrophils and monocytes was studied after incubation with prostasomes isolated from normal human seminal plasma. The following functional tests were employed: ability to ingest latex particles and opsonized bacteria (St. aureus) and ability to generate superoxide anion in response to PMA and FMLP. The latter was determined by measuring the superoxide-dismutase inhibitable reduction of ferricytochrome c to ferrocytochrome c at 550 nm. Expression of cell surface markers and interactions of prostasomes with cells were studied by cytofluorimetry. RESULTS: We show that prostasomes bind rapidly to the leukocyte cell membrane followed by internalization of adsorbed material. Interactions of prostasomes with neutrophils and monocytes inhibits their ability to phagocytose latex particles. The ability to ingest opsonized bacteria is, however, not impaired. Our results also show that incubation of leukocytes with prostasomes effectively inhibits superoxide anion generation in response to activation by PMA and FMLP. CONCLUSIONS: Prostasomes may play a complementary role to other immunosuppressive factors contained in the human semen. They may protect sperm cells from deleterious effects of phagocytosing cells, prolong their life, and consequently enhance the chance of conception. At the same time prostasomes may have a permissive effect on sexually transmitted diseases.

Cell Adhesion↗
PubMed1991

Effects of mifepristone in vivo on decidual prostaglandin synthesis and metabolism.

Mifepristone is an effective abortifacient in combination with an exogenous prostaglandin but its mechanism of action is unknown. Mifepristone stimulates prostaglandin production from decidua in tissue culture. To determine whether this effect also operates in vivo, we treated women with mifepristone 24, 36 and 48 hours prior to surgical termination. Decidua was removed at operation and the ability of the tissue to generate prostaglandin in culture subsequently assessed. Pretreatment with mifepristone 36 hours prior to termination of pregnancy resulted in an increased production of PGF2 alpha in tissue culture (p less than 0.01). A significant decrease in PGFM production was seen 24 hours after pretreatment with mifepristone in vivo (p less than 0.01). These results suggest that the increased uterine activity observed after administration of mifepristone may be due to stimulation of endogenous prostaglandin production and inhibition of prostaglandin metabolism.

Culture Techniques↗
PubMed1991

The mechanisms of action of progesterone and the anti-progestin ZK 98734 on PGF2 alpha synthesis by early human decidua.

The inhibition of prostaglandin (PG) synthesis found in early human decidua is antagonized by the anti-progestin, ZK 98734. This action of ZK 98734 is abolished by actinomycin, an inhibitor of protein synthesis and by the calcium channel blocker, verapamil. Calmidazolium, an antagonist of the intracellular calcium binding protein calmodulin was less effective in inhibiting the stimulation of PG synthesis induced by the anti-progestin. Chronic stimulation of protein kinase C activity by 1-oleoyl-2-acetyl-sn-glycerol (OAG) induced a slight reduction of PG release and was antagonized by polymixin. These findings suggest that inhibition of PG synthesis in early pregnancy is caused by progesterone and that increased release of PGs induced by anti-progestins is dependent on new protein formation and requires extracellular calcium.

Abortion, Spontaneous↗