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Biomedical subjects

M A Warren

Publications and source records attributed to M A Warren.

At least 19 recordsLinked to original sources
PubMed2001

Interleukin-11 (IL-11) in human endometrium: expression throughout the menstrual cycle and the effects of cytokines on endometrial IL-11 production in vitro.

Interleukin-11 is a member of the IL-6 family of cytokines. Its presence in mouse decidua has been shown and experiments in genetically modified mice have suggested the importance of its receptor in stromal cell decidualization. In this study we used immunocytochemistry to determine expression of IL-11 in human endometrium. The effects of TNFalpha, IL-1alpha and TGFbeta on IL-11 production by epithelial and stromal cells was also investigated. Immunocytochemical staining in sections cut from 19 endometrial biopsies obtained throughout the menstrual cycle showed that IL-11 was expressed in both human endometrial epithelial and stromal cells, with epithelial staining being more intense than that seen in the stromal cells, at all times except the late secretory phase when the intensity was similar. Basal IL-11 production by cultured epithelial cells was greater than basal production by stromal cells. IL-1alpha, TNFalpha and TGFbeta (0.1-10 ng/ml) all caused a concentration-dependent increase in IL-11 production by both epithelial and stromal cells, but stimulated: basal values were greater for stromal than epithelial cells for all three cytokines. This work shows, for the first time, the presence of IL-11 within the human endometrium and that its production is controlled by other cytokines, which are postulated to play a role in implantation. Thus IL-11 may also play an important role in human endometrial function and embryo implantation.

Adult↗
PubMed1999

Morphological evidence for the 'implantation window' in human luminal endometrium.

Endometrial tissue was taken from 21 normal fertile women (aged 18-40 years) between 4 and 13 days after the luteinizing hormone (LH) surge. Systematic random samples of luminal epithelium were taken for both light and electron microscopy and examined morphometrically. Throughout the luteal phase there were remarkably few changes in the volume fraction of nucleus, mitochondria, rough endoplasmic reticulum and 'vesicular system' to cell. Nuclear profile dimensions and cell height also did not change over time. Cell and organelle volume (estimated as volume weighted mean volume) did not change significantly, but showed numerically smallest values on day LH + 13. However the ratio of desmosomes to whole cell and both arithmetic mean thickness and harmonic mean thickness of basement membrane were minimal at the time when implantation would be most likely to occur, i.e. approximately 6 days after the LH peak. Therefore it appears that while some morphometric parameters in human luminal epithelial cells change little during the luteal phase, specific cellular changes occur to the basement membrane and desmosomes which may facilitate embryo implantation. These changes occurred around day LH+ 6 and may be a morphological representation of the 'implantation window'.

Adolescent↗
PubMed1998

Synthesis and characterisation of oligodeoxynucleotides containing thio analogues of (6-4) pyrimidine-pyrimidinone photo-dimers.

A method for the preparation of an oligodeoxynucleotide, 20 bases in length, containing centrally located thio analogues of (6-4) pyrimidine-pyrimidinone thymine photo-dimers is reported. The approach is based on the selective irradiation, at 350 nm, of a Tp4ST (4ST = 4-thiothymidine) step within a 20-mer having the sequence: d(ACTCGGACCT(4sT)CGCTGTGAT). Conversion of the S5-(6-4)/S5-thietane pyrimidine-pyrimidinone, initially formed, to its S5-Dewar isomer is by a subsequent irradiation at 300 nm. Both of the photo-dimer-containing oligonucleotides were purified by HPLC (ion exchange and reverse phase) and characterised by base composition analysis. The S5-(6-4)/S5-thietane pyrimidine-pyrimidinone containing 20-mer has a characteristic UV absorbance at 320 nm and exhibits strong fluorescence when excited at this wavelength. As expected, conversion to the S5-Dewar isomer abolished both the 320 nm absorbance and the fluorescence emission. The lengths of the oligonucleotides produced allowed the formation of stable double-stranded DNA, by hybridisation to a complementary sequence. Examination of these duplexes by circular dichroism spectroscopy showed that they formed B-DNA, with little changes to their gross structure as compared to the parent duplex. However, local structural perturbations in the region of the photo-dimer cannot be excluded. The S5-(6-4)/S5-thietane photoproduct lowered the tm by 10.5 deg. C and the Dewar isomer by 12 deg. C. The degree of curvature induced in the DNA sequence by the introduction of the photo-dimers was assessed by analysing the migration of modified and unmodified multimer ladders on polyacrylamide gels. Both photoproducts induced considerable bending into the DNA. A comparison with a six-base-pair T tract, a bending standard that has a known bend angle of 19 degrees, gave values of around 47 degrees for the S5-(6-4)/S5-thietane product and about 28 degrees for the S5-Dewar isomer.

DNA↗
PubMed1997

Response of human spermatozoa to an internal calcium ATPase inhibitor, 2,5-di(tert-butyl) hydroquinone.

This study has investigated the effect of elevating intracellular calcium levels, using an internal calcium ATPase inhibitor, 2,5-di(tert-butyl) hydroquinone (TBQ), on human sperm function. Isolated sperm samples from five fertile donors were incubated in a capacitating media for up to 6 hr. After 0, 3, and 6 hr incubation, sperm were exposed to a range of TBQ concentrations; 100 microM, 10 microM, and 1 microM, for a fixed incubation period of 5 min. Controls were run for each experiment where sperm were incubated for 5 min in the absence of TBQ. Sperm capacitation and the acrosome reaction were monitored prior to and after exposure to TBQ, using the Chlortetracycline assay. In addition, sperm motility was assessed at each time point and after sperm had been exposed to TBQ. The treatment of sperm with TBQ caused a significant increase in the number of capacitated sperm with an optimum response being achieved in the presence of 100 microM TBQ. However, sperm motility was found not to be effected by the addition of TBQ. The results from the present study suggest that elevating intracellular calcium levels in human sperm by short exposure to a high concentration of TBQ can rapidly accelerate the capacitation process. Furthermore, the observation that TBQ did not elicit a change in sperm motility suggests that TBQ may be highly specific in its mode of action by acting within the head region of human sperm.

Acrosome↗
PubMed1997

Elevating intracellular calcium levels in human sperm using an internal calcium ATPase inhibitor, 2,5-di(tert-butyl) hydroquinone (TBQ), initiates capacitation and the acrosome reaction but only in the presence of extracellular calcium.

The aim of this study was to investigate the effect of an internal calcium ATPase inhibitor, TBQ, on human sperm capacitation and the acrosome reaction during incubation in a calcium-depleted media. Sperm were isolated into and incubated for up to 6 hr in media depleted of Ca2+ and two Ca(2+)-containing media controls. At set time intervals, sperm in each media group were treated with 100 microM TBQ for 5 min. Afterwards, sperm were induced to acrosome react using the divalent cation ionophore, A23187, as a measure of sperm fertilizing potential. It was established, using the Chlortetracycline assay, that incubation of sperm in a Ca(2+)-depleted media inhibited or delayed sperm capacitation resulting in fewer spontaneous or A23187-induced acrosome reacted sperm. However, incubation of sperm in a Ca(2+)-depleted media did not appear to inhibit sperm motility. The treatment of sperm with TBQ during their incubation in Ca(2+)-depleted media was found to have very little effect resulting in low numbers of capacitated and acrosome reacted sperm. The results from this study suggest that human sperm have an obligatory requirement for extracellular calcium during capacitation and the acrosome reaction, but may require either very little extracellular Ca2+ to maintain motility or possess internal Ca2+ stores sufficient for their requirements. In addition, TBQ did not increase the number of capacitated and acrosome reacted sperm during incubation in a Ca(2+)-depleted media suggesting that the TBQ-effect of accelerating sperm capacitation is dependent on presence of extracellular Ca2+.

Acrosome↗
PubMed1997

The effect of a single dose of mifepristone (RU486) on the fine structure of the human endometrium during the early luteal phase.

This study examined the fine structure of the human endometrial glandular epithelium after the administration of a single dose of RU486 (mifepristone), given in the early luteal phase. The drug was administered on days 2, 3, 5 and 6 after the luteinizing hormone peak (LH + 0). Biopsies were performed on days LH + 5, 6, 8 and 9. These were compared with control biopsies taken on corresponding days. Qualitatively, the main cytological effect of the RU486 was on the secretory apparatus and on the polarity of the cell. The formation of the nuclear channel system was also affected by the drug. A two-way analysis of variance on cell and nuclear volume data revealed no significant effect of day of biopsy, condition or interaction. Mitochondrial volume and secretory apparatus volume data revealed a significant effect of day of biopsy and interaction term; mitochondrial volume at LH + 5 was 95.9 +/- 25.3 microm3 (mean +/- SD) for control and 57.7 +/- 31.9 microm3 for RU486-treated epithelium. The volume of the secretory apparatus in the treated group was smaller on days LH + 5 and 6 (14.6 +/- 4.2 microm3, 6.41 +/- microm3) when compared to day-matched control biopsies (35.9 +/- 10.5 microm3, 41.7 +/- 26.4 microm3). RU486 administration in the early luteal phase disrupted the secretory activity of the cells. These findings provide an insight into the cellular mechanisms of progesterone receptor blockade in the peri-implantation period.

Adolescent↗
PubMed1997

Greater numbers of human spermatozoa associate with endosalpingeal cells derived from the isthmus compared with those from the ampulla.

A simple co-culture bioassay system was used to investigate whether or not the anatomical origin affected the ability of epithelial cells from the human uterine (Fallopian) tube to 'bind' spermatozoa. This study was also used to identify some of the factors which may be involved in the regulation of sperm-epithelial interactions in vitro by comparing different tissue culture models and assessing the effect of oestradiol concentration. Epithelial explants harvested from different regions of human uterine tubes were co-incubated with a known concentration of motile donor spermatozoa. All results were adjusted to reflect a standard sperm concentration of 5 x 10(6)/ml. More spermatozoa associated per field of isthmic compared to ampullary epithelium [isthmus 9.5 +/- 0.9, ampulla 7.1 +/- 0.7 (mean +/- SEM); n = 36, P < 0.05, ANOVA] and cells from post-menopausal patients had an apparently reduced ability to bind spermatozoa [isthmus 5.5 +/- 2.0, ampulla 4.3 +/- 1.4 (mean +/- SEM); n = 4]. Neither menstrual cycle stage nor addition of mid-cycle concentrations of 17beta-oestradiol (750 pmol/l) affected the number of spermatozoa which bound to epithelium from either tubal region. In addition, the number of spermatozoa which bound per field of polarized explants was greater (P < 0.05) than that bound to dissociated primary and passaged epithelial cell monolayers. This report is the first to provide evidence suggestive of a role for sperm-epithelial binding in the formation of an isthmic sperm reservoir in the human uterine tube. Results also indicate that oestrogen is not involved in the regulation of these interactions, and that cell polarity is an important factor for such associations in vitro.

Cell Adhesion↗
PubMed1997

Effects of non-conservative changes to tyrosine 76, a key DNA binding residue of DNase I, on phosphodiester bond cleavage and DNA hydrolysis selectivity.

Non-conservative changes, consisting of Y76E, Y76L, Y76Q and Y76W, have been made to tyrosine 76, one of the key DNA binding residues in DNase I. Normally Y76 inserts into the minor groove of DNA and makes an unusual, hydrophobic, stacking interaction with one of the sugars. All four mutants bind to DNA more tightly than the wild type, but cut it more slowly as assessed by Kunitz assays. This gives a rather small decrease in the specificity constants (Vmax/K(m)) for the hydrolysis of DNA, which is roughly paralleled by the loss of activity towards the non-DNA small chromophoric substrate, thymidine-3',5'-di(p-nitrophenyl)phosphate. These non-conservative mutants, therefore, show different behaviour to Y76A and Y76G, studied previously [Doherty A.J., Worrall A.F. and Connolly B.A. (1995) J: Mol. Biol., 251, 366-377]. These two mutants both bind to and cut DNA poorly, resulting in large decreases in Vmax/K(m) values. However, they showed little reduction in rates with the chromophoric substrate. It is likely that the altered side chains in the non-conservative mutants are still able to interact productively with the DNA and contribute to the observed DNA distortion that is essential for efficient catalysis. However, these mutations disrupt the active site, most probably by interference with the hydrogen bonded Y76-E78-H134 triad. H134 is a critical hydrolytic residue of DNase I that is essential for catalysis. The DNA cleavage selectivity of the Y76E, Y76L, Y76Q and Y76W mutants were little altered as compared with the wild-type enzyme as measured using the cutting patterns of a 160 base-pair Escherichia coli Tyr T promoter DNA fragment. This confirms earlier observations, with Y76F, Y76A and Y76G, that showed that this tyrosine has little role in DNA cleavage specificity.

Autoradiography↗
PubMed1996

Changes in nuclear morphology in the human endometrial glandular epithelium in women with unexplained infertility.

In the light and electron microscopical study reported here, we documented the structure of the nucleus, nucleolus and nuclear channel system (NCS) in the uterine glandular epithelium in both fertile and infertile women during the early luteal phase. Nuclear volume was found to be larger in the infertile group at day 5 after the luteinizing hormone surge (LH+5) compared to day-matched fertile subjects. A two-way analysis of variance performed on nucleolar volume data from fertile and infertile women biopsied on days LH+5, +5, and +6 revealed a significant effect of condition but no effect of day or interaction. Nucleolar volume decreased from day LH+2 to day LH+6 in the fertile group, the sharpest decrease occurring between day LH+3 and day LH+4. The largest mean volume of the NCS was found at day LH+5 in the fertile group and day LH+6 in the infertile group. The results suggest a delay in the development of this organelle in the infertile women. The present study has documented alterations in the nuclei of uterine glandular cells from infertile patients. In these infertile women, there is also a delayed elaboration of the secretory apparatus and this delay correlates well with the delayed/reduced expression of a luteal-specific glyco-protein.

Analysis of Variance↗
PubMed1996

Comparative study of the effect of human cervical mucus and a cervical mucus substitute, Healonid, on capacitation and the acrosome reaction of human spermatozoa in vitro.

The present study was designed to investigate the effect of human cervical mucus on capacitation and the acrosome reaction of human spermatozoa and compare its effect to that of a cervical mucus substitute, sodium hyaluronate (Healonid). Spermatozoa from donors of proven fertility were isolated from semen using cervical mucus, Healonid or a direct swim-up (acting as the control). Sperm capacitation and the acrosome reaction were monitored by the chlortetracycline assay. In the mucus-treated group, there was a significantly higher percentage of capacitated spermatozoa, but a low incidence of spontaneous and A23187-induced acrosome reactions compared to the control. The use of Healonid during sperm isolation mimicked the effect of mucus relatively successfully. Since mucus and Healonid show very little chemical similarity, this finding would imply that cervical mucus exerts a physical effect during its interaction with spermatozoa, although a chemical effect cannot be completely dismissed. In conclusion, this study confirms early reports describing the ability of cervical mucus to capacitate spermatozoa but at the same time conserve sperm function. The finding that Healonid exerts an almost identical effect on spermatozoa would lend support to its use as a cervical mucus substitute during in-vitro fertility assessments and research studies.

Acrosome↗
PubMed1996

St. Francis Hospice: Medicare and health care reform.

The St. Francis Hospice Program is symbolic of more than 100 years of Franciscan dedication to the people of Hawaii. Since Mother Marianne's arrival in November of 1883, the Sisters of the Third Franciscan Order Syracuse, New York have responded to the calling; "the charity of Christ impels us." It is through this calling that care and comfort for the terminally ill is a part of the mission of St. Francis Healthcare System. The magnificent spirit through which Hospice services have been made possible, is a reflection of God's great generosity to us throughout the years.

Hawaii↗
PubMed1995

The production of placental protein 14 by human uterine tubal epithelial cells in culture.

Cells prepared from the mucosal layer obtained from the fimbrial, proximal ampullary and distal ampullary regions of the human uterine (Fallopian) tube have been grown in monolayer culture. Immunocytochemistry with anti-cytokeratin, anti-vimentin or anti-CD 45 antibodies indicated that the overwhelming number of cells were epithelial in nature and were free of fibroblasts and leukocytes. Basal and steroid-stimulated placental protein 14 (PP14) production was investigated in tissue obtained from nine patients undergoing hysterectomy, by addition of oestradiol and/or progesterone to confluent cultures. Basal PP14 production varied considerably between experiments, probably due to differences between individuals from whom the tissue had been obtained. However, there was no difference in basal PP14 production by cells prepared from the fimbrial, proximal ampullary and distal ampullary parts of the tube obtained from the same patient. When total PP14 production by cells obtained from an individual uterine tube was pooled both progesterone and oestradiol significantly (P < 0.05) stimulated the production of PP14 but the effect of progesterone either alone or in the presence of oestradiol was numerically greater than that of oestradiol alone. Considering PP14 production by cells prepared from the different regions of the tube showed that cells from the fimbrial region were more responsive to steroid stimulation than cells prepared from either the proximal or the distal ampullary regions. All combinations of hormonal supplementation stimulated PP14 production by cells from the fimbrial region on all days measured (P < 0.05 - P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Cells, Cultured↗
PubMed1995

Hyperactivation may assist human spermatozoa to detach from intimate association with the endosalpinx.

The behaviour of human spermatozoa was observed during incubation with epithelial cells isolated from the isthmic and ampullary sections of human uterine (Fallopian) tubes. During incubation, spermatozoa were observed to bind to the epithelial cells of the tube (the endosalpinx), and individual spermatozoa attached and detached at intervals. The kinematic characteristics of spermatozoa during these behaviour patterns were determined. The results showed that detached spermatozoa typically had an increased curvilinear velocity and amplitude of lateral head displacement, accompanied by a decrease in their linearity. Significantly (P < 0.01) more of the detaching spermatozoa were hyperactivated than were spermatozoa prior to attachment for both isthmic (35.3 +/- 5.5 versus 4.0 +/- 3.3%; mean +/- SEM) and ampullary (26.0 +/- 7.0 versus 2.0 +/- 1.4%) regions. Incubation with epithelial cells from either region produced no differences in any category of sperm behaviour. Furthermore, there was no significant difference between regions in the amount of time spermatozoa spent bound (33.6 +/- 12.9 and 20.6 +/- 3.0 s for isthmic and ampullary tissue respectively). These results support the hypothesis that hyperactivation may assist spermatozoa in breaking connections with epithelial cells.

Cell Adhesion↗
PubMed1995

The measurement of CA 125 and placental protein 14 in uterine flushings in women with recurrent miscarriage; relation to endometrial morphology.

The concentrations of CA 125 and placental protein 14 (PP14) were measured in uterine flushings obtained throughout the luteal phase of the cycle from eight normal fertile women. The concentrations of both proteins increased in a similar pattern throughout the luteal phase of the cycle, with the most dramatic increase occurring 6 days after their luteinizing hormone surge (day LH +6). However, a greater variation in CA 125 concentrations was seen compared to that seen for PP14. The concentrations were compared to those obtained on day LH +7 of the cycle from a group (n = 35) of women with recurrent miscarriage. The ranges in concentration of PP14 and CA 125 in the flushings of fertile and recurrent miscarriage patients were very similar. However, a greater proportion of women with recurrent miscarriage (55%) had low concentrations (< 5 ng/ml) of PP14 than in the control group (12.5%) and the concentrations of PP14 in the uterine flushings were significantly less (P < 0.05) in women with recurrent miscarriage compared to the normal fertile group. There was no significant difference in the concentration of CA 125 in the uterine flushings between the two groups. Histological observation of the endometrial biopsy samples from recurrent miscarriage patients gave menstrual cycle datings that ranged from day LH +2.5 to LH +6.5 with retarded endometrium (< day LH +5) in 12 of 35 (34%) patients. Of these 12 patients, 10 (83%) had low PP14 concentrations and six (50%) had low CA 125 concentrations in their uterine flushings. In the recurrent miscarriage patients with histologically normal (> or = day LH +5) endometrial development, 10 out of 23 (43%) also had low PP14 concentrations and 8 out of 23 (35%) had low CA 125 in their uterine flushings. The results suggest that PP14 is better than CA 125 as a marker for endometrial function in this group of women. In some cases (52%) the low concentrations of PP14 in the uterine flushings could be explained by retarded endometrial development but for the others the reduction in PP14 concentration in the uterine flushing was not associated with retardation of endometrial development.

Abortion, Habitual↗
PubMed1995

The interaction in vitro of human spermatozoa with epithelial cells from the human uterine (fallopian) tube.

The physical interaction between human spermatozoa and the epithelium of the human uterine (Fallopian) tube was investigated in vitro using a variety of techniques. The 'live' observation of human spermatozoa incubated with 1 day old cultures of tubal epithelium demonstrated that spermatozoa can show a strong physical interaction with epithelial cells; contact with the epithelium appeared to be random and there was no evidence of any taxis toward epithelial cells. The physical interaction (or 'binding') was resistant to gentle washing and was maintained following the addition of glutaraldehyde fixative. The intimate nature of the interaction was confirmed ultrastructurally where both spermatozoa and epithelial membranes were observed to be in close apposition. These results are the first descriptions of sperm-epithelial 'binding' in the human. They are similar to other observations made in a variety of non-human mammalian species. It is suggested that this interaction may be an important feature of normal sperm transport in the human uterine tube in vivo.

Cell Communication↗
PubMed1995

A light microscopical morphometric study of the luminal epithelium of human endometrium during the peri-implantation period.

Different aspects of the histology of luminal epithelial cells were examined quantitatively at the light microscopical level. For the first time, using a variety of morphometric indices, an attempt was made to quantify and compare the cellular events in a group of well defined fertile controls and infertile subjects during the peri-implantation period. The most striking observation was that the majority of the features examined, including all nuclear parameters and most cell dimensions, were similar and did not differ significantly between the fertile controls and the infertile subjects over the period of study. The coefficients of variation of most of the parameters investigated were similar and within a narrow range in both the fertile and infertile population, indicating little variation either between individuals at a particular stage or between subjects on different days. This low inter-subject variability may suggest that the cellular events which we have been able to quantify at the light microscope level in the uterine surface epithelium around the anticipated time of implantation are precisely regulated. Such precise regulation does not mean that changes do not occur in luminal epithelial cells during this time, but that those which do occur are well controlled and co-ordinated. Possible changes in biochemistry, physiology and ultrastructure of these cells remain to be determined.

Adult↗
PubMed1995

Morphologic observations on the dermal nerves in vitiligo: an ultrastructural study.

BACKGROUND: Vitiligo is a common idiopathic skin disorder. The etiology is unknown, although various hypotheses have been advanced. These include the neuronal hypothesis, where neuronal factors are thought to play a role in the pathogenesis of this disease. METHODS: Skin biopsies were taken from marginal and central parts of four vitiligo patients. Biopsies were also taken from nonvitiliginous skin of each patient and from four normal control subjects. Sections were examined under the electron-microscope. Nerve fibers in the superficial dermis were examined. RESULTS: Subtle ultrastructural changes, including regeneration and degeneration, were consistently found in dermal nerves of vitiligo lesions. The most consistent feature, seen in all four vitiligo patients studied (in both lesional and marginal areas), was an increased thickness of the basement membrane of Schwann cells. This change was found in approximately three-quarters of all dermal nerves in vitiligo biopsies, but in only about one-quarter of dermal nerves in normal control skin. About half the abnormal dermal nerves in vitiligo skin showed minor axonal damage, although indicators of regeneration (increased mitochondria and rough endoplasmic reticulum) predominated. The dermal nerves in vitiligo showed no difference in fiber diameter or fiber density in comparison with controls. CONCLUSIONS: In vitiligo both axonal degeneration and nerve regeneration may occur, with the latter possibly being a reactive change to earlier axonal damage. These findings support the hypothesis that there is a neuronal component to this disease.

Adult↗