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J D Aplin

Publications and source records attributed to J D Aplin.

At least 91 records · Page 5Linked to original sources
PubMed1989

Luteal phase defect: the possibility of an immunohistochemical diagnosis.

Monoclonal antibody D9B1 has been shown to bind to a carbohydrate epitope associated with high molecular weight secretory sialoglycoprotein(s) of human endometrium. The authors demonstrate that, in a group of 28 patients diagnosed on the basis of histopathologic assessment as exhibiting luteal phase defect, 68% reveal significantly diminished expression of the epitope. Furthermore, histologic assessment of the secretory activity in single glands does not correlate simply with the level of expression of the epitope. Of specimens from patients complaining of infertility, 92% showed defective production of the D9B1 epitope. Thus, D9B1 immunohistochemistry provides a new molecular criterion for defective endometrial function.

Antibodies, Monoclonal↗
PubMed1989

The endometrial cycle: the expression of a secretory component correlated with the luteinizing hormone peak.

This paper reports the pattern of production and secretion of a secretory phase epitope in the endometrium of 44 normal fertile women. Peroxidase immunochemistry was used to detect the monoclonal antibody D9B1, which binds to a peptide-associated sialylated oligosaccharide, in endometrial biopsies all chronologically dated from the luteinizing hormone (LH) peak. During the proliferative phase, the epitope was shown to be absent from tissue sections. It first made its appearance within gland cells 2 days after the LH peak. By LH+3 a rapid accumulation of the D9B1 epitope was noted in the base of the cell, below the nucleus. On subsequent days, increasing amounts of the antigen were detected in the apical cytoplasm, apparently in a more concentrated form than in the basal cell zone. On day LH+6, around the time of implantation, secretory vesicles in the cell apex were discharged into the gland lumen where the glycoconjugate finally accumulated. This immunohistochemical approach introduces a new parameter for evaluation of endometrial function and could be used to improve the accuracy of histological assessment of the endometrial cycle.

Adolescent↗
PubMed1989

Attempts to identify trophoblast in peripheral blood during pregnancy using monoclonal antibody H315.

In view of its potential importance in antenatal diagnosis of genetic disease, we have used flow cytometry to attempt to enumerate trophoblast cells in the peripheral blood of pregnant females. As a trophoblast marker we have used the monoclonal antibody (MAB) H315, which reacts with placental-type alkaline phosphatase (PLAP) associated with the cell-membrane of the syncytiotrophoblast. We analyzed blood leucocytes from 62 pregnant females between 6 and 22 weeks' gestation, 26 nonpregnant females, and 21 males. Overall, we detected more H315+ cells in pregnant than in nonpregnant female blood but, because of the wide variation in both groups, we found no statistically significant difference between them. We were unable to detect H315+ cells in 25% of pregnant females within the resolution of the technique. There was, in contrast, a significant difference between the number of H315+ cells in pregnant females and males. Because we were unable to demonstrate other trophoblast markers on H315+ cells isolated from maternal peripheral blood, the origin of these cells is unclear. This implies that these cells may be an unsuitable source of material for antenatal diagnosis.

Antibodies, Monoclonal↗
PubMed1989

The translaminal fibrils of the human amnion basement membrane.

The organisation of extracellular matrix beneath the human amniotic epithelium was investigated in order that the co-ordinate synthesis of basal lamina and stroma by these cells could be better understood. Transmission electron microscopy of intact tissue confirmed that stromal matrix fibrils are located between the cell surface and the basal lamina, and also penetrate the lamina. The distribution of the supralaminal fibrils and their association with the lamina was further investigated by scanning electron microscopy (SEM) after removal of the overlying epithelium. Five complementary procedures were used to remove the cells from the underlying lamina. Trypsin-EDTA treatment caused the epithelial cells to retract or detach from the lamina. SDS or ammonium hydroxide was used to extract the epithelium, which was then removed by physical shearing. Transmission electron microscopy (TEM) confirmed that the lamina densa and supralaminal fibres were present after extraction by these agents. Incubation in CHAPS, a zwiterionic detergent, did not remove the epithelium but permitted exposure of the basal lamina by mechanical scoring. Extraction with boric acid followed by osmium tetroxide produced epithelial disruption and revealed the lamina and stroma in different areas. Although the extraction pattern was different in each case, all of the five methods confirmed that individual fibrils and fibril bundles are present on the apical surface of, and enter, the lamina densa. Examination of the stromal surface of the basal lamina after fracture revealed fibrils passing from the stroma into the lamina densa. We therefore suggest that, in this tissue, newly synthesised stromal matrix components appear in an assembled fibrillar form between the basal cell surface and the basal lamina before becoming associated with the sublaminal stroma.

Amnion↗
PubMed1988

An immunohistochemical study of human endometrial extracellular matrix during the menstrual cycle and first trimester of pregnancy.

Changes in the organisation and composition of extracellular matrix in human endometrium during the menstrual cycle and early pregnancy have been assessed by immunofluorescence. Amongst interstitial components, type-III and type V-collagens and fibronectin are present in endometrial stroma throughout the menstrual cycle as well as in first trimester decidua. Type V-collagen epitopes are masked early in the cycle, but become accessible in first trimester decidua. Type VI-collagen is abundant in endometrium in the proliferative phase, but is progressively lost in the secretory phase and decidua, in which it is retained only in blood vessel walls. Vitronectin is present in some blood vessels in decidua. Decidualising stromal cells also produce basement membrane components (type IV-collagen, laminin, heparan sulphate proteoglycan and a glycoprotein family recognised by monoclonal antibody G71) and these become organised into a pericellular aura.

Basement Membrane↗
PubMed1988

Expression of a secretory product by microvillous and ciliated cells of the human endometrial epithelium in vivo and in vitro.

A monoclonal antibody which identifies a component of post-ovulatory endometrial secretions is now shown to be expressed within the cytoplasm and on the cell surface of both microvillous and ciliated epithelial cells. A glandular explantation model was developed in order to study the 'carry over' of this secretion to the regenerative phase endometrium. A loss of cytoplasmic antigen was observed in vitro. However, it was retained on the cell surface in a fashion consistent with its expression at the time of explantation. Mosaicism of expression of this secretory component occurs throughout the secretory-phase and is particularly pronounced at the time of transition from proliferative to secretory phase. It is concluded that both ciliated and microvillous epithelial cells produce a post-ovulatory secretory component which may be retained on the cell surface in the absence of hormonal stimulation.

Cells, Cultured↗
PubMed1988

Surface visualisation of tissue interfaces by scanning electron microscopy. Methods for exposure of the basal lamina and associated structures in human amnion.

Tissue interfaces such as basal lamina have been traditionally investigated in transmission electron microscopy by sections cut vertical to the lamina, presenting information restricted to a single ultrathin plane. In order to overcome this limitation, a methodology for surface visualisation of the underside cell membranes of the amniotic epithelium, the upper and lower basal lamina surfaces, and their relationship to the stromal collagen has been devised. This involves alkaline, detergent or enzymatic loosening and/or removal of the epithelial monolayer prior to fixation, followed by dry fracture after critical point drying. In this way we have visualised large areas of all interfaces and the inter-relationships between these elements during the process of stromal collagen production by the amniotic epithelial cells.

Ammonium Hydroxide↗
PubMed1987

A monoclonal antibody to a cell surface determinant in human endometrial epithelium: stage-specific expression in the menstrual cycle.

A monoclonal antibody (CC25) was obtained after immunization of mice with intact glandular epithelial cells from secretory phase endometrium. Here we report a preliminary immunohistologic study in the endometrium of 29 patients in different phases of the menstrual cycle and early pregnancy. In immunofluorescence, CC25 binds to a basolaterally oriented epithelial cell surface antigen that is absent during the proliferative phase and appears suddenly in both glandular and uterine surface locations soon after ovulation. In mid and late secretory phase, the level of expression diminishes slowly. The epitope is absent from glandular epithelial cells in first-trimester decidua. However, it is associated with vascular smooth muscle cells in endometrium and decidua. CC25 promises to be a useful reagent for the analysis of endometrial function during the menstrual cycle.

Animals↗
PubMed1985

Monensin-dependent and -independent mechanisms of cell-matrix adhesion.

Attachment and spreading of human FL cells on a subcellular matrix (SCM) preparation made by treating confluent cell monolayers with deoxycholate are insensitive to the presence of monensin. However, if the cell suspension is surface-iodinated prior to adhesion using the LPO/H2O2 system, cell spreading on SCM is inhibited by 1 microM monensin. The suggested interpretation is that cell surface components required for cell spreading on SCM are inactivated by iodination and need replacement from intracellular reserves by a monensin-sensitive pathway. This pathway is not required in the absence of iodination when sufficient surface components (or a monensin-independent pathway of surface expression) are available. Support for this interpretation is obtained by means of double-iodination experiments in which surface-labelled cells adhere and spread, are detached and labelled a second time and then allowed to adhere again to SCM. Cell spreading in the second case is inhibited by approximately 80%, suggesting that both previously expressed and newly recruited receptors are inactivated.

Amnion↗
PubMed1985

Basally located epithelial cell surface component identified by a novel monoclonal antibody technique.

Tubular aggregates of glandular epithelial cells (gland fragments) were isolated from human endometrium by collagenase digestion of surrounding stroma, thus exposing the basal surfaces of the cells. Using these aggregates as immunogen, monoclonal antibodies could be derived that recognized basally located antigens. One such antibody, G71, is described, that binds to a basal epithelial cell antigen present in a variety of human epithelia. Epitope-bearing molecules in the range Mr 60 000-180 000 are present in two of the tissues studied, amnion and endometrium. The epitope is associated with areas of epithelial cell-extracellular matrix contact.

Amnion↗
PubMed1985

Defective adhesion to extracellular matrix leads to altered social behaviour in cultured fibroblasts.

We describe the properties of variant mouse fibroblasts selected for poor adhesion to growth substratum containing subcellular matrix accumulated by adherent cells at confluence. The variant cells adhere to virgin plastic and grow normally to confluence in the presence of serum. After subculture and reseeding onto the same surface the cells initially adhere, but after a further 2 days of growth they retract into aggregates and detach. If the aggregates are dispersed and cells reseeded onto the same surface they remain rounded. However, if the same cells are added back to virgin plastic they adhere and grow normally. The retraction can be abolished by treating the subcellular matrix-coated plastic with papain. This behaviour therefore reflects the ability of the cells to modify the composition of the underlying substratum during growth. The variant cells also exhibit retraction 2 days after seeding on a surface previously containing wild-type cells at confluence, while wild-type cells do not retract on subcellular matrix deposited by variants. This shows that the variant behaviour arises not from a deficiency in the subcellular matrix, but from an alteration in the adhesive capacity of the cells. The results are interpreted in terms of three putative adhesion mechanisms: cell-cell adhesion in confluent monolayers and aggregates; 'early' type cell-substratum adhesion, which occurs during culture on virgin plastic; and 'late' type cell-substratum adhesion occurring on surfaces containing accumulated subcellular matrix. The variant phenotype is characterized by a deficiency in the last of these. It is also associated with an increased ability to grow in suspension culture at high dilution.

Animals↗
PubMed1985

The extracellular matrix of human amniotic epithelium: ultrastructure, composition and deposition.

Ultrastructural comparisons have been made between human amnion extracellular matrix in tissue and cell culture. Immunochemical analysis of matrix deposited by monolayers of cultured amnion epithelial cells has also been undertaken. The basal cell surfaces are highly invaginated with an associated basal lamina that is more electron dense at the distal tips of basal cell processes where hemidesmosomes are frequent. Immediately below the lamina densa is a zone rich in collagen bundles. In the underlying stroma two types of fibril predominate, one striated of 50 nm diameter and one of 18 nm diameter. The observations suggest that at gestational term the epithelial cells are still active in the production of matrix. Secretion appears to occur into invaginations in the basal cell surface where a loosely organized mixture of stromal-type and basal laminal-type aggregates is formed. In culture on plastic, cells also deposit a mixture of basal laminal (type IV collagen + laminin) and stromal (collagens type I + III) components as well as fibronectin. However, segregation into a true basal lamina with underlying stroma does not occur in vitro, suggesting the need for an organized subcellular template to complete matrix morphogenesis. The in vitro and in vivo evidence suggest that the epithelium contributes to the subjacent dense collagenous zone as well as to the basal lamina.

Amnion↗
PubMed1984

Adhesion of human amnion epithelial cells to extracellular matrix. Evidence for multiple mechanisms.

Human amnion epithelial cells attach and flatten slowly (approximately 65 min) onto plastic in the presence of serum but much more rapidly (20-30 min) onto subcellular matrix (SCM) deposited by the same cells. This matrix contains both fibronectin and laminin, but neither molecule on its own can reproduce its adhesive properties. Cells attach on surfaces containing fibronectin and laminin and extend filopodial and lamellipodial areas of cytoplasm without extensive flattening in the perinuclear region. Matrix deposited onto plastic by amnion epithelial cells has trypsin-sensitive and trypsin-resistant, papain-sensitive adhesion-promoting components. Cell spreading triggered by the latter but not the former can be inhibited by pretreating the adhering cells with heparin. Other GAGs are without effect. The results are discussed in terms of multiple interactions between epithelial cells and basal laminae.

Amnion↗
PubMed1984

Novel substratum-dependent dendritic morphology and motility in epithelial cells.

Qualitative and quantitative light microscopy including time-lapse observations, and scanning electron microscopy are applied to study the response of cultured primary amnion epithelial cells to surfaces coated with a fibronectin-containing aggregate extracted from placenta (PSF). Cell shapes are compared with those observed in medium containing serum and amniotic fluid. Cells respond rapidly to PSF in serum-free medium to give unusual dendritic structures. Cell bodies remain rounded with numerous long and complex processes appearing and disappearing over a period of 6 to 6 1/2 h. This behaviour is associated with an 18-fold increased motility relative to control cells. Few attachments to substratum occur beneath cell bodies or along dendritic processes, points of adhesion being largely confined to the termini of extensions. Later in the response to PSF, a reduction in cell extensions is accompanied by flattening of the cell body and more conventional shapes reminiscent of control cells are restored. In serum, cells spread more slowly to give well-flattened discoid or polygonal morphologies. In amniotic fluid, blebbed, bipolar and asymmetrical cells are observed with some dendritic extensions, reminiscent of those seen on PSF. The profound influence of substratum-associated ligands on cellular behavior is noted.

Amnion↗
PubMed1983

Kinetic analysis of cell spreading. I. Theory and modelling of curves.

The spreading of cells on suitably treated surfaces is briefly discussed and the need to analyse this phenomenon numerically is emphasized. Possible mathematical models for fitting experimental data are classified as statistical, kinetic or empirical and examples of each of these types are given. A possible protocol for analysing cell spreading kinetics and determining goodness of fit and parameter redundancy is presented.

Cell Line↗
PubMed1983

Kinetic analysis of cell spreading. II. Substratum adhesion requirements of amniotic epithelial (FL) cells.

The kinetics of spreading of trypsinized FL cells on plastic or glass substrata covalently or passively coated with various proteins to make simplified model extracellular matrices have been measured. Kinetics have also been obtained in the presence and absence of serum and amniotic fluid. Data from such experiments are shown to be sigmoid and have been computer-fitted with great accuracy to 12 mathematical models discussed in the accompanying paper. A log normal distribution function is shown to give the best fit over 18 different types of experiment. For the first time, therefore, such data can be characterized quantitatively and compared. We obtain the simple parameters mu (mean time to spread) and sigma (standard error of the mean) and show that the cells spread most rapidly in amniotic fluid or on fibronectin 'carpets'. They also spread rapidly on a fibronectin-fibrinogen complex extracted from placenta. Spreading is slower in serum, in amniotic fluid lacking fibronectin and on type I collagen or cellular microexudate from FL cells or fibroblasts. On concanavalin A, spreading is rapid but the distribution of times to spread (as expressed by sigma) is relatively wide.

Amnion↗