Ultrastructural changes in the synthetic and secretory patterns of pulmonary surfactant following pilocarpine in vivo

Previous studies have demonstrated that the muscarinic agonist pilocarpine stimulates the secretion of pulmonary surfactant from mammalian alveolar type II cells. The results of the present study quantify, via ultrastructural stereologic analysis, this response through 24 hours. The cytoplasmic volume density of lamellar bodies decreases significantly at 0.5 and 4 hours post-injection. This value is increased significantly at 12 hours post-injection. Elements of the secretory apparatus increase significantly at many of the post-injection times. At 12 hours post-injection many of the type II cells are quite laden with lamellar bodies, with some appearing surprisingly large. This may be a useful model for continued study of the relationship between synthesis and secretion of pulmonary surfactant.

Distribution of the A and B forms of the progesterone receptor messenger ribonucleic acid and protein in uterine leiomyomata and adjacent myometrium

The two forms of the progesterone receptor, PR-A and PR-B, are independently regulated at the transcriptional level, and show distinct responses to progesterone antagonists. We were interested in possible differences in the PR-A to PR-B ratio between uterine myometrium and leiomyomata (fibroid), that might influence the response of fibroids to progesterone agonists and antagonists, and thus have consequences for the treatment of this condition. Fibroid and adjacent normal myometrium were obtained from 11 women undergoing hysterectomy. Immunohistochemistry using a monoclonal antibody which recognizes both PR-A and PR-B showed exclusively nuclear staining, and this was stronger in the leiomyomata than in adjacent myometrium. An antibody specific for PR-B gave fainter staining of both tissues. Western blotting confirmed a higher concentration of PR in leiomyomata than myometrium in eight out of 11 cases. In all cases both forms were present, with a consistent dominance of PR-A over PR-B. However an RNase protection assay showed that there was no difference between the concentrations of mRNA encoding PR-A and PR-B, or between the mRNA concentrations in leiomyomata and normal myometrium. We conclude that the observed differences between the levels of immunoreactive PR in leiomyomata and myometrium may result from post-translational control, and support the use of progesterone antagonists in the treatment of leiomyomata.

Immunolocalization of the apoptosis regulating proteins Bcl-2 and Bax in human endometrium and isolated peritoneal fluid macrophages in endometriosis

Endometriosis, a debilitating disease associated with infertility, is characterized by the prolonged presence of ectopic endometrial tissue and the involvement of activated peritoneal fluid macrophages. Apoptosis, which occurs in both endometrium and peritoneal fluid macrophages, is controlled in part by members of the Bcl-2/Bax family of proteins. Here, through immunohistochemical staining, we investigated the Bcl-2/Bax status in endometrium and peritoneal fluid macrophages in endometriosis. Bcl-2/Bax immunoreactivity was found predominantly in the glandular epithelial cells, mainly during the proliferative phase of the menstrual cycle for Bcl-2 but throughout the entire menstrual cycle for Bax. Ectopic endometrium contained a population of Bcl-2 positive. Bax negative tissue macrophages. Fluorescence-activated cell sorting of isolated peritoneal fluid macrophages showed that women with endometriosis had a significantly higher proportion of Bcl-2 positive macrophages than the non-endometriotic group. The proportion of Bax positive peritoneal fluid macrophages was significantly elevated in women without endometriosis. The increased proportion of Bcl-2 positive macrophages found in women with endometriosis may predispose these cells to resist apoptosis. The continued survival of these active cells could have important consequences for the survival and proliferation of the ectopic endometrial tissue.

In-vivo gene transfer to the uterine endometrium

Therapeutic interventions in reproductive biology have relied largely on steroids and antisteroids which act to regulate gene expression in target tissues. Whilst their use has transformed women's lives, few conceptual advances have been made in contraceptive technology, no means identified to improve human implantation and no new strategies developed for the treatment of benign gynaecology. A novel alternative is direct gene transfer to the organ of interest. As a first step to achieving this goal in the uterus, we used reporter gene constructs to transfect mouse endometrium in vivo and human endometrial epithelial cells in vitro. We injected DNA-liposome complexes into the uterine lumen of mice on day 2 of pseudopregnancy and detected reporter gene activity 2 days later. The liposomes used were a 3:1 (w/w) mixture of 2,3-dioleyloxy-N-[2(sperminecarboxamido) ethyl]-N-N-dimethyl-1-propanaminium trifluoroacetate and dioleoylphosphatidyl ethanolamine. Freshly isolated human endometrial epithelial cells were successfully transfected in vitro with similar DNA-liposome complexes. These data suggest that endometrial gene transfer may be effective in humans. This may lead to the development of new therapeutic agents, including contraceptives, for the improvement of women's health.

Maternal plasma levels of vascular endothelial growth factor in normotensive pregnancies and in pregnancies complicated by pre-eclampsia

We have measured the level of vascular endothelial growth factor (VEGF) in maternal plasma during normotensive pregnancy and in pregnancies complicated by pre-eclampsia. VEGF was measured using a competitive enzyme immunoassay. Plasma VEGF was significantly elevated (P < 0.0001) in the pre-eclamptic group (median value 32.7 ng mL-1, range 10.3-64.0), compared with the normotensive group (median value 11.7 ng mL-1, range 6.3-24.3). VEGF is a potent regulator of endothelial cell function. The increased level found in women with pre-eclampsia indicates that VEGF may be involved in the maternal endothelial cell dysfunction associated with this condition. An increase in VEGF, a potent regulator of microvascular permeability, may also contribute to the extravasation of plasma proteins and the subsequent development of proteinuria, both characteristic features of pre-eclampsia.

VEGF mRNA levels in placentae from pregnancies complicated by pre-eclampsia

OBJECTIVE

To measure the mRNA levels of vascular endothelial growth factor and its receptor in the placenta following delivery after uncomplicated pregnancy and after pregnancies complicated by pre-eclampsia.

SETTING

Rosie Maternity Hospital, Cambridge.

MATERIAL

Placental biopsies were obtained following delivery by caesarean section in 23 cases of pregnancy presenting at a range of gestational ages with pre-eclampsia. These were compared with biopsies from 20 appropriately matched women with uncomplicated pregnancies.

MAIN OUTCOME MEASURE

mRNA levels of vascular endothelial growth factor (VEGF) and its receptor the fins-like tyrosine kinase (flt), were quantified in total RNA isolated from placental biopsies using the RNAse protection assay. The amount of RNA was compared with that of the housekeeping gene glyceraldehyde 3-phosphate dehydrogenase (GAPDH), used as a standard. Results were expressed as arbitrary optical density units of VEGF/GAPDH and flt/GAPDH.

RESULTS

In both control and pre-eclamptic women regression analysis showed that the level of mRNA encoding VEGF declined significantly with gestational age (P < 0.0001). However, levels of VEGF mRNA were significantly lower in the pre-eclamptic women compared with the control women (P < 0.023).

CONCLUSIONS

This study provides evidence of an abnormality of growth factor expression in the placenta during pregnancies complicated by pre-eclampsia. Such placentae exhibit deficient growth and differentiation of terminal villi and reduced fetal capillary branching and reduced levels of VEGF could well account for these morphometric changes. This finding provides a molecular explanation for this abnormal placental development and points to VEGF as a factor in the aetiology of pre-eclampsia and its complications.

Hepatocyte growth factor/scatter factor and its receptor c-met: localisation and expression in the human placenta throughout pregnancy

Hepatocyte growth factor (HGF), also known as scatter factor, acts via the c-met receptor resulting in pronounced effects on certain epithelial cells. We hypothesised that HGF would be important in placental development where the trophoblast represents a specialised barrier of epithelial origin. In this paper we examine the expression and production of HGF and its receptor in the human placenta throughout pregnancy. In addition, RT-PCR was undertaken on human embryos to ascertain whether pre-implantation embryonic or trophoblast cells were under the influence of this growth factor. In samples from the first trimester of pregnancy in situ hybridisation with a c-met antisense probe detected message expression in villous cytotrophoblast and in decidual glands but not in extravillous trophoblast. Some c-met expression was detected in cytotrophoblast from the second trimester placentae; this declined to negligible levels by term. Staining with an anti c-met antibody largely confirmed these findings but found relatively strong staining of cytotrophoblast at term. HGF was confined to the villous core throughout pregnancy when examined by both in situ hybridisation and immunohistochemistry. Trophoblast was consistently negative for HGF. Pre-implantation embryos examined by RT-PCR were negative for both c-met and HGF mRNA. These results indicate that the HGF may exert an important influence on cytotrophoblast throughout the process of placental formation and growth.

Expression of prostacyclin and thromboxane synthases in placenta and placental bed after pre-eclamptic pregnancies

Prostacyclin and thromboxane are potent antagonistic regulators of vascular tone and platelet aggregation. In pre-eclampsia, the ratio of their metabolites is decreased. Little is known about the local regulation of intrauterine prostacyclin and thromboxane production in this condition. Placenta and placental bed biopsies were obtained from uncomplicated and pre-eclamptic pregnancies. Prostacyclin synthase (PCS) and thromboxane synthase (TXS) and their mRNA's were localized by immunohistochemistry using monoclonal antibodies and in situ hybridization. Protein and mRNA levels were quantified by immunoblot and RNase protection assay. PCS-like immunoreactivity was found in endothelial cells and leiomyocytes, whereas fetal and maternal macrophages showed positive staining for TXS. Their mRNA was localized to trophoblast and endothelium, and TXS mRNA could also be detected in macrophages. Quantitative analysis showed no significant difference in intrauterine protein or mRNA expression after pre-eclampsia. The prostacyclin and thromboxane production seems to be compartmentalized within the uteroplacental unit. The expression of their synthesizing enzymes might be regulated post-transcriptionally. Additional regulation of prostaglandin production could be metabolically or on the substrate level and requires further elucidation.

Activation of protein kinase C is required for oxytocin-induced contractility in human pregnant myometrium

Intracellular mediators regulating the initiation of parturition are not fully understood. This study was designed to determine the possible mechanism of oxytocin-induced uterine contractility during labour. In-vitro isometric contraction studies were performed with longitudinal strips of human pregnant myometrium in the presence and absence of the protein kinase C inhibitors, staurosporine and RO 31-8220, and the tyrosine kinase inhibitor, genistein. Phospholipase D activity was measured by employing the transphosphatidylation reaction. Staurosporine significantly reduced oxytocin-stimulated contractile activity with mean activity reduced by > 50% following the addition of 10(-6) M staurosporine (P < 0.01), while addition of 10(-5) M resulted in a measured mean contractile activity of approximately 10% of the control (P < 0.001, n = 5). Similarly, uterine activity was minimal with oxytocin application following incubation with RO 31-8220, mean contractile activity being reduced by approximately 40% by the addition of 10(-7) M RO 31-8220 (P < 0.05) and by approximately 87% by the addition of either 10(-6) or 10(-5) M (P < 0.01, n = 3). Conversely, addition of genistein (10(-7) and 10(-6) M) had little effect on oxytocin-induced contractions, although at a higher concentration (10(-5) M) a significant reduction in oxytocin-induced contractile activity was observed (P < 0.01). Oxytocin evoked phospholipase D activation in a concentration- and time-dependent manner in cultured human pregnant myometrial cells (n = 4). These results indicate that activation of protein kinase C and tyrosine kinase are involved in the regulation of oxytocin-mediated myometrial contractile activity and that a coupled phospholipase D/phosphatidate phosphohydrolase pathway may play a role in the sustained stimulation of myometrial activity during labour.

Messenger RNA encoding thiol protein disulphide isomerase in amnion, chorion and placenta in human term and preterm labour

OBJECTIVE

To investigate levels of messenger RNA (mRNA) encoding thiol protein disulphide isomerase, in human amnion, chorion and placenta during pregnancy and in relation to term and preterm labour.

DESIGN

Amnion, chorion and placenta from 33 women delivered between 24 and 41 weeks of gestation were used in the study.

SETTING

Reproductive Molecular Research Group, Department of Obstetrics and Gynaecology, University of Cambridge Clinical School, Rosie Maternity Hospital, Cambridge.

RESULTS

Women who were delivered spontaneously before 30 weeks of gestation had higher levels of mRNA encoding thiol protein disulphide isomerase in placenta and chorion than those who were delivered spontaneously after this time (placenta (P < 0.01, chorion P < 0.01) and compared with those who were delivered by elective caesarean section before 30 weeks of gestation (placenta (P < 0.01, chorion P < 0.05). In the group in whom spontaneous labour occurred, at all gestations studied, there were increased levels of mRNA encoding thiol protein disulphide isomerase in the placenta (P < 0.001) and chorion (P < 0.001) compared with the amnion.

CONCLUSION

Changes in the steady state level of mRNA encoding thiol protein disulphide isomerase may play a role in the onset of preterm labour before 30 weeks of gestation.

Characterization and expression of vascular endothelial growth factor (VEGF) in the ovine corpus luteum

The corpus luteum undergoes tremendous growth, development and regression each oestrous or menstrual cycle. These changes are reflected by equally impressive growth and regression of the luteal vasculature. We have previously shown that angiogenic factors from corpora lutea are primarily heparin binding and that one of these factors is similar to vascular endothelial growth factor (VEGF). In an effort to identify this factor, and to define its role in luteal vascular development, the cDNA for the coding region of ovine VEGF was sequenced and a sensitive RNase protection assay was developed to quantitate mRNA encoding VEGF in luteal tissues from ewes in the early (days 2-4), mid- (day 8) and late (days 14-15) stages of the oestrous cycle. In addition, an N-terminal peptide was synthesized from the translated ovine cDNA sequence for VEGF and an antiserum was raised against this peptide for use in western immunoblotting procedures. Nested reverse transcriptase (RT)-PCR of RNA from ovine corpora lutea resulted in three products that correspond in size to the alternatively spliced variants of VEGF (VEGF120, VEGF164, and VEGF188) predicted from other species. The RNase protection assay revealed that the proportion of mRNA encoding VEGF was 2- to 3-fold greater on days 2-4 than on day 8 or days 14-15. Densitometric analysis of gels from the RNase protection assay showed that VEGF120 represented approximately one third of the total mRNA encoding VEGF in the corpus luteum and that this proportion did not vary with stage of the oestrous cycle. SDS-PAGE and western immunoblot analysis of a homogenate from corpora lutea showed a single 18 kDa protein. These data demonstrate that VEGF is expressed in luteal tissue throughout the ovine oestrous cycle and that expression of mRNA encoding VEGF is upregulated during the period of rapid luteal development, when luteal vascular growth is at its maximum.

Vascular endothelial growth factor is produced by peritoneal fluid macrophages in endometriosis and is regulated by ovarian steroids

Angiogenesis is important in the pathophysiology of endometriosis, a condition characterized by implantation of ectopic endometrium in the peritoneal cavity. Vascular endothelial growth factor (VEGF) is a potent angiogenic factor involved in physiological and pathological angiogenesis, and elevated levels of VEGF are found in peritoneal fluid of patients with endometriosis. Our aim was to investigate the site of expression and regulation of VEGF in endometriosis. VEGF immunoreactivity was found in tissue macrophages present in ectopic endometrium and in activated peritoneal fluid macrophages. Macrophage activation was highest in women with endometriosis, and media conditioned by peritoneal fluid macrophages from these women caused a VEGF-dependent increase in endothelial cell proliferation above that seen from normal women. Peritoneal fluid macrophages secreted VEGF in response to ovarian steroids, and this secretion was enhanced after activation with lipopolysaccharide. Peritoneal fluid macrophages expressed receptors for steroid hormones. VEGF receptors flt and KDR (kinase domain receptor) were also detected, suggesting autocrine regulation. During the menstrual cycle, expression of flt was constant but that of KDR was increased in the luteal phase, at which time the cells migrated in response to VEGF. KDR expression and the migratory response were significantly higher in patients with endometriosis. This study demonstrates that activated macrophages are a major source of VEGF in endometriosis and that this expression is regulated directly by ovarian steroids.

Localization of VEGF and expression of its receptors flt and KDR in human placenta throughout pregnancy

Vascular endothelial growth factor (VEGF) is a potent secreted angiogenic growth factor. Its action is mediated through the tyrosine kinase receptors flt and KDR. We here examine, in detail, the distribution of this ligand and its receptors in human placentae throughout gestation. In the first trimester, in-situ hybridization revealed uneven distribution of flt mRNA around the villous trophoblast indicating spatial regulation. Temporal regulation of flt was observed with no flt mRNA expression detected in villi from mid-gestational placenta, while low levels were found in term villi. Extravillous trophoblast was found to contain both mRNA encoding flt and flt-like immunoreactivity throughout pregnancy. In contrast, KDR mRNA was found only in association with endothelial cells. Within the decidua the anti-flt antibody stained multiple cell types during the first trimester of pregnancy but only the extravillous trophoblast later in gestation. VEGF immunoreactivity tended to co-localize with the staining for flt. These results indicate that VEGF may exert an important role within both the placental villi and the maternal decidua in relation to the growth, differentiation and migration of trophoblast and that this is mediated primarily through the spatial and temporal regulation of the flt receptor rather than the KDR receptor.

Demographic effects of natural disasters: a case study of Hurricane Andrew

Many studies have considered the economic, social, and psychological effects of hurricanes, earthquakes, floods, tornadoes, and other natural disasters, but few have considered their demographic effects. In this paper we describe and evaluate a method for measuring the effects of Hurricane Andrew on the housing stock and population distribution in Dade County, Florida. Using information collected through sample surveys and from other data sources, we investigate the extent of housing damages, the number of people forced out of their homes, where they went, how long they stayed, and whether they returned to their prehurricane residences. We conclude that more than half the housing units in Dade County were damaged by Hurricane Andrew; that more than 353,000 people were forced to leave their homes, at least temporarily; and that almost 40,000 people left the county permanently as a direct result of the hurricane. We believe that this study will provide methodological guidance to analysts studying the demographic effects of other large-scale natural disasters.

Patient noncompliance with wearing and replacement schedules of disposable contact lenses

BACKGROUND

Corneal ulcers related to contact lens wear are four to 15 times more likely to occur with extended wear lenses versus daily wear lenses. The introduction of disposable contact lenses raised hopes that this product would reduce complications related to contact lens wear. Such has proven not to be the case, especially when patients are noncompliant with the prescribed wear and care regimen.

METHODS

The ordering patterns of a group of 145 patients wearing disposable contact lenses were monitored for a period of one year, 5 months in an attempt to identify those individuals who were potentially noncompliant in their wearing schedules.

RESULTS

Up to 69 percent of the patients studied were identified as potentially noncompliant. A program to counsel and re-educate these patients about proper disposable contact lens wear was proposed.

CONCLUSIONS

Eye care professionals have a legal and ethical responsibility to provide appropriate follow-up care for patients. The ability to track ordering patterns of patients who wear disposable contact lenses provides a valuable tool to use in identifying patients who could be putting themselves at risk to develop complications related to contact lens wear.

Immunisation of sheep with an integral membrane glycoprotein complex of Haemonchus contortus and with its major polypeptide components

Sheep were immunised against Haemonchus contortus with an integral membrane glycoprotein complex isolated from the intestines of the parasite as antigen. This antigen has been termed Haemonchus galactose-containing glycoprotein complex. Sodium dodecyl sulphate (SDS) polyacrylamide gel analysis has shown that it is composed of several polypeptides but so far these have proved refractory to separation when in the native state. However when dissociated by SDS, it was found to be as efficacious as in its native state, although it was less consistently protective when tested after being dissociated and reduced. An attempt was therefore made to identify the protective ingredient(s) of the dissociated complex by testing its major polypeptides individually after they had been separated on SDS polyacrylamide gels under non-reducing conditions. Partial protection was induced by protein bands with molecular weights of about 200 kD and less than 50 kD, but none of the individual fractions tested was as efficacious as the unseparated complex, suggesting that either more than one component was essential for a consistent effect or that the separation technique had damaged crucial protective epitopes.

Cloning, expression and genomic organization of human placental protein disulfide isomerase (previously identified as phospholipase C alpha)

Phosphoinositol-specific Phospholipase C plays an important role in transducing receptor generated signals to the rest of the cell. A cDNA encoding a phospholipase has been described (Bennett et al., 1988, Nature 334, 268-270). However it is probable that this cDNA in fact encodes a protein disulfide isomerase. Since the original work suggested that this enzyme was important in the reproductive tract we sort to clone, sequence, express and characterize the recombinant protein isolated from the placenta. We have cloned and sequenced the cDNA encoding the human homolog of this cDNA from human placenta, although the mRNA was widespread in the female reproductive tract. We have transiently expressed it in both COS cells and also 1BR fibroblasts. Cell lysates were assayed for increased phospholipase activity and protein disulfide activity. We describe the entire cDNA sequence which is highly conserved between species. We have also cloned a portion of the genomic gene and described the intron/exon boundaries. In vitro translation of this cDNA showed that it encoded a protein of 61 kD with a cleavable signal peptide. Transient expression showed the protein produced had no phospholipase activity but did show protein disulfide isomerase activity. The expression work shows that this cDNA indeed encodes a protein disulfide isomerase and not a phospholipase. The nucleotide sequence shows marked conservation of the coding and regulatory regions which may suggest that this enzyme has evolved to perform a highly specialized function.

Vascular endothelial growth factor (VEGF) concentrations are elevated in peritoneal fluid of women with endometriosis

Active endometriosis is characterized by hypervascularization both within and surrounding the implant; therefore the presence of angiogenic factors in the peritoneal environment would be of great importance. Vascular endothelial growth factor (VEGF) is a potent angiogenic factor involved in both physiological and pathological angiogenesis. We sought to determine if VEGF was present in the peritoneal fluid of women with and without endometriosis, and to establish if differences exist between these groups. VEGF was present in all patients sampled. The fluid from patients with endometriosis contained significantly greater amounts of VEGF than controls. Cyclic variations in VEGF concentration were seen in fluid from patients with endometriosis, the VEGF concentration in proliferative phase being significantly higher than in the secretory phase. The concentration of VEGF in this fluid was also significantly higher than that found in the proliferative and secretory phases of women without endometriosis. No cyclic variations in VEGF were seen in the control group. We suggest that elevated levels of VEGF in the peritoneal fluid of patients with endometriosis may be critical in the pathogenesis of endometriosis.

Localization of vascular endothelial growth factor and its receptor, flt, in human placenta and decidua by immunohistochemistry

Vascular endothelial growth factor is a secreted angiogenic growth factor the mRNA of which is present in the placenta. The mRNA encoding the vascular endothelial growth factor receptor, flt, has also been demonstrated in placenta, with trophoblast appearing to be a novel site of flt expression. We investigated the expression of both vascular endothelial growth factor and flt-like immunoreactivity in first trimester and term placentae. In the first trimester, vascular endothelial growth factor immunoreactivity was localized to placental macrophages (Hofbauer cells), and in decidua, to glandular epithelium and maternal macrophages. In the term placenta, vascular endothelial growth factor immunoreactivity was present in extravillous trophoblast and in extracellular material. Flt immunoreactivity was demonstrated on extravillous trophoblast in first trimester and term, and on Hofbauer cells within placental villi. This complex pattern of both vascular endothelial growth factor and flt-like immunoreactivity suggests that vascular endothelial growth factor may be involved not only in the regulation of placental angiogenesis, but also in trophoblast invasion.

Stage-specific expression of cytokine and receptor messenger ribonucleic acids in human preimplantation embryos

There is considerable evidence to suggest that polypeptide growth factors from either the oviduct or the endometrium can control preimplantation development of the mammalian embryo. These act directly through receptors expressed on the embryo. In addition, embryos also produce growth factors. The reverse transcriptase-polymerase chain reaction (RT-PCR) was used to determine the pattern of expression of mRNAs encoding several growth factor ligand and receptor genes throughout preimplantation development of cryopreserved human embryos. Transcripts encoding the receptor for c-fms, the receptor for colony-stimulating factor-1 (CSF-1), and c-kit (the receptor for stem cell factor [SCF]) were expressed throughout preimplantation development. Other growth factor ligand and receptor transcripts were expressed in a stage-specific manner: these included receptors for interleukin (IL)-6 (IL-6R), leukemia inhibitory factor (LIFR), tumor necrosis factor alpha (TNF alpha) (TNFRp80 and TNFRp60), and gp130. The transcripts for gp130 and the ligand SCF showed stage-specific splice variants. Blastocysts expressed a novel cDNA encoding gp130, which predicts a truncated form lacking the intracellular signaling domain. No expression of mRNAs encoding LIF, CSF-1, or the cloned receptor for platelet-activating factor was seen in any embryonic stage studied. We have shown that RT-PCR provides a sensitive and powerful method for identifying transcripts encoding growth factors and their receptors in single human embryos. The method is economical, allowing the expression pattern of many genes to be determined from a single embryo. These data are important in defining which cytokines may be involved in regulating human preimplantation development and when they may act.