Association Between Depression and Anxiety Status With Uptake of Colorectal Cancer Screening Among US Adults: A Population-Level Study.

BACKGROUND: Individuals with different mental disorders tend to experience higher rates of colorectal cancer (CRC)-related mortality compared to the general population. Discrepancies in CRC screening behaviors have been suggested as a potential contributing factor to this difference in mortality. However, existing evidence on this topic has been inconclusive and conflicting. OBJECTIVE: This study aims to explore the relationship between mental health status (specifically, depression and/or anxiety) and the uptake of CRC screening. To achieve this, a larger and nationally representative sample from the adult population of the United States was utilized. METHODS: We employed a cross-sectional approach using data from the 2019-2020 edition of the Health Information National Trends Survey (HINTS). The study examined disparities in CRC screening between individuals with self-reported history of depression diagnosis and the general population. Chi-square tests were used for analysis. Multivariable logistic regression models were applied to adjust for variables such as gender, age, education level, race, comorbidities, healthcare access, smoking status, household income, geographical residence, and insurance status. Adjusted odds ratios (AORs) with 95% confidence intervals (CIs) were reported. RESULTS: The findings of the study indicated that out of 5,398 eligible individuals, approximately 1,220 (weighted percentage: 22.8%) reported experiencing depression and/or anxiety, and approximately 4,154 (weighted percentage: 68.9%) reported adherence to colorectal cancer screening. In the bivariate analysis, there was no significant difference in participation in colorectal cancer screening between individuals with and without depression and/or anxiety (72.0% vs. 68.0%). Similarly, after adjusting for sociodemographic and health-related factors, the study found that the odds of participating in colorectal cancer screening did not vary based on an individual's depression status (OR 1.34, 95% CI 0.94-1.91, P = 0.05). CONCLUSION: Individuals with depression participate in colorectal cancer screening at comparable rates to the general population. The findings of this study suggest that factors beyond CRC screening may play significant roles in the higher CRC-associated mortality rate. Therefore, further research is needed to uncover the various mechanisms contributing to the increased cancer-related mortality rates among susceptible populations.

Simplified approach for in-vitro production and purification of cell derived Cancer Antigen 15-3.

Cancer antigen 15-3 (CA15-3) is a key biomarker, currently used for understanding the onset and prognosis of breast cancer. In present investigation, CA15-3 has been purified from the culture supernatant of breast cancer T47-D cell line with 76% yield and 3350 fold purification. Isolated CA15-3 was analyzed by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), immunoblotting (western blotting), chemiluminescence immunoassay (CLIA) and Fourier-transform infrared spectroscopy (FTIR). CA15-3 is a monomeric protein with an apparent molecular mass in between ∼250-350kDa. The FTIR spectroscopy revealed similar profiles of T47-D derived CA15-3 and commercially available CA15-3 protein. With the easy availability of T47-D cell line and a simple purification approach described here will support for the large scale production of CA15-3 to be used for various clinical and diagnostic applications.

Development of an indirect immunofluorescence based assay for diagnosis of ulcerative colitis in Indian population.

The prevalence of Ulcerative Colitis (UC), once thought to be negligible, has increases exponentially in the Indian population. The development of novel, cost effective and time efficient Indirect Immunofluorescence (IIF) based assay for detection of anti-neutrophil cytoplasmic antibodies (ANCA) and diagnosis of UC in the Indian population is discussed. A novel IIF based assay was developed using intact nuclei from human neutrophils to detect atypical p-ANCA in patients suffering from UC. Sera from 45 patients diagnosed with UC, 45 healthy controls and one related disease control were tested using a novel UC-ANCA assay and validated by commercially available ANCA IIF assay. Prevalence of ANCA amongst UC patients in the Indian population was determined. Atypical p-ANCA was detected in 86.6% of the patients using the UC-ANCA assay as compared to 71.1% using the commercial ANCA assay. The validation of UC-ANCA assay with a commercially available ANCA IIF assay resulted in higher sensitivity. The UC-ANCA assay proved to be not only enhanced in terms of performance but also comparatively economical and rapid. The novel UC-ANCA assay may prove to be very useful in identification and differentiation of UC patients from typical ANCA positive subjects suffering from other autoimmune diseases at one tenth the cost of clinically available ANCA IIF tests which will immensely benefit the cost constrained diagnostic field of developing countries.

Development of glycan specific lectin based immunoassay for detection of prostate specific antigen.

We describe an analytical approach for the detection and verification of glycosylation patterns of prostate specific antigen (PSA), a key biomarker currently used for understanding the onset and prognosis of prostate cancer. PSA has been purified from the human seminal plasma and total PSA from prostate cancer sera. PSA is a monomeric glycoprotein with an apparent molecular mass 28040.467 Da, which exhibits a characteristic protease activity against casein and gelatin. Its optimal protease activity is centered on neutral pH. Peptide mass fingerprint analysis of the purified PSA has yielded peptides that partially match with known database sequences (Uniprot ID P07288). Tryptic digestion profile of isolated PSA, infer the exclusive nature of PSA and may be additive molecule in the dictionary of seminal proteins. Surface plasmon resonance and lectin immunoassay revealed direct interaction between a newly developed anti-PSA monoclonal antibody (C4E6) and PSA. A lectin based immunoassay is reported here which was achieved with the C4E6 anti-PSA antibody and biotinylated plant lectins. This investigation provides an alternative method to isolate and quantify PSA with altered glycosylation which might be seen in the prostate cancer and developing a lectin based immunoassay to detect PSA in serum of prostate cancer patients.

Proliferation and decidualization of endometrial stromal cells during embryo-attachment stage in bonnet monkeys (Macaca radiata).

We report embryo-induced alterations occurring in endometrial stromal cells (ESCs) during the embryo-attachment stage in bonnet monkeys (Macaca radiata). Laser micro-dissected ESCs obtained from pregnant and non-pregnant animals were compared for levels of selected proliferation and decidualization-associated factors by analysis with quantitative real-time polymerase chain reaction or immunohistochemistry. Stromal cells exhibited extensive cellular proliferation, as indicated by cellular compaction and significantly higher (P < 0.05) levels of proliferating cell nuclear antigen and of estrogen receptor 1, c-Myc, and Cyclin D1 transcripts in pregnant animals as compared with non-pregnant animals. A significant decrease (P < 0.05) was observed in the transcript levels of stromal interleukin-6 (IL-6) in pregnant animals. Cell proliferation was accompanied by a significant increase (P < 0.001) in the levels of decidualization-associated molecules such as IL-1ß in the luminal and glandular epithelium and of stromal insulin-like growth-factor-binding protein-1 (IGFBP-1) and prostaglandin-endoperoxide synthase-2 (PTGS-2) proteins. In pregnant animals, proliferation was evident throughout the gestational stroma, whereas decidualization was more pronounced in the embryo-attachment zone than in the non-attachment zone. To our knowledge, this is the first report of alterations in the endometrial stroma during the embryo-attachment stage in a non-human primate model.

Endometrial epithelial cell modifications in response to embryonic signals in bonnet monkeys (Macaca radiata).

The present investigation reports embryo-induced modifications in the epithelial cells of the endometrium in a primate species. In vivo, epithelial cell response to the embryonic signals was assessed at the embryo attachment stage in the gestational uterus of bonnet monkeys (Macaca radiata) and in vitro response was investigated by treating human endometrial epithelial cell line (Ishikawa) with human embryo conditioned media (CM). Endometrial epithelial (EE) cells at the embryo attachment stage in bonnet monkeys revealed higher proliferation accompanied by significant up regulation (p < 0.05) in the expression of estrogen receptor (ER)α and down regulation (p < 0.05) in ERß expression. Further gestational EE cells showed higher (p < 0.001) expression of mucin-1, except in the embryo attachment site. Also, observed were significantly higher expression (p < 0.05) and altered cytoplasmic distribution of α(v) and ß(3) integrins, when compared to non-pregnant animals. In pregnant animals, the embryo attachment zone showed differential expression of immunoreactive integrins as compared to the non-attachment zone. This suggested the role of embryo secreted factors in modulation of the epithelial cell profile. In vitro studies partially supported this assumption. Significantly higher proliferation (p < 0.05), as well as increased expression of ERα, integrin ß(3) and mucin-1 (p < 0.05) were observed in Ishikawa cells, on stimulation with CM. Taken together, these results indicated the proliferation and modulation in the expression of estrogen receptors and cell adhesion molecules in the EE cells; at the embryo attachment stage in bonnet monkeys. Further it is likely that embryo secreted factors contribute to some of these modifications in EE cells. This report is the first account of discrete cellular events, which occur in the uterine epithelium, at the embryo attachment stage in a primate species.

Embryo-induced alterations in the molecular phenotype of primate endometrium.

Reproductive biomedicine has made significant advances in the area of assisted reproductive technologies in the last two and half decades. However, embryo implantation remains a major obstacle in securing high pregnancy rates. Various non-human primate models including rhesus, marmoset and baboon have been employed to elucidate in vivo mechanisms underlying the uterine events that initiate, sustain and complete implantation. This review collates the information available on the molecular profile of gestational endometrium in primates. Collectively, these studies reveal dynamic spatio-temporal changes in the expression of cytokines, growth factors, cell-adhesion molecules, cytoskeleton elements and other factors in the endometrium during the post-implantation phase of pregnancy. Considering that the endometrial events during the pre-implantation stages of pregnancy may dictate implantation success, we have developed a bonnet monkey (Macaca radiata) model where pregnancy can be detected at the pre-implantation stage. Using this model, we investigated some of the endometrial events that occur before the completion of implantation. Remarkable changes were observed in endometrial expression of pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNFalpha), as well as expression of immunosuppressive factors such as transforming growth factor beta-2 (TGFbeta2), interleukin-6 (IL-6) and placental protein-14 (PP-14), even before the embryo starts invading the endometrium. This highlights the super-imposition of endometrial receptivity by embryonic stimuli, marked by differential expression and/or localization of the factors that regulate endometrial transformation for embryo survival, growth and development.

Expression of endometrial protein kinase a during early pregnancy in bonnet monkeys (Macaca radiata).

Embryo-induced signaling pathways are considered to be important for initiation and sustenance of pregnancy. However many of these pathways remain to be deciphered in primates. In the present study, differential display RT-PCR was used to identify genes or gene fragments that are differentially expressed in endometrium of bonnet monkeys (Macaca radiata) on Day 6 of pregnancy. Of several fragments found to be differentially expressed, a fragment of 567 base pair (named GG1) was characterized in detail. GG1 was highly represented in endometrium of pregnant animals compared with that of nonpregnant animals. Sequencing analysis revealed homology of this fragment to exons 7, 8, 9, and 10 and surprisingly to intron 6 of cAMP-dependent protein kinase A (PKA) regulatory type I alpha (tissue-specific extinguisher 1) (PRKAR1A). The increased expression of this fragment in gestational endometrium was confirmed by quantitative PCR studies. Two transcripts of 3.0 kilobase (kb) and 1.5 kb were detected in Northern blot probed with labeled GG1. Protein expressions of alpha regulatory (PRKAR1A) and alpha catalytic (PRKCA) subunits of PKA were also higher in gestational endometrium compared with that in nongestational endometrium. Further in vitro studies using human endometrial explants demonstrated regulation of PRKAR1A (or GG1) and prostaglandin-endoperoxide synthase 2 or cyclooxygenase 2 (PTGS2) by estradiol. This is the first study to date on the differential expression of PKA in primate endometrium during early pregnancy and its in vitro regulation by estradiol.

Protein profiling of human endometrial tissues in the midsecretory and proliferative phases of the menstrual cycle.

OBJECTIVE: To identify the proteins displaying differential expression in midsecretory phase endometrium as compared with proliferative phase endometrium. DESIGN: Prospective study with two groups of women in the midsecretory or proliferative phase. SETTING: Clinical research outpatient department. PATIENT(S): Healthy, regularly cycling women of proven fertility. INTERVENTION(S): Collection of endometrial biopsy samples. MAIN OUTCOME MEASURE(S): Image analysis software was used to compare two-dimensional protein maps of midsecretory phase endometrial tissues (MSE) with maps of proliferative phase endometrial tissues (PROE) and midsecretory phase uterine fluids (MSU). Matrix-assisted laser desorption/ionization time of flight in tandem (MALDI-TOF-TOF) analysis was carried out to identify eight proteins that were differentially expressed between the two phases and also to identify the spots that shared similar coordinates in the two-dimensional maps of MSE and MSU. RESULT(S): Densitometry analysis and subsequent MALDI-TOF-TOF analysis revealed up-regulation of calreticulin, the beta chain of fibrinogen, adenylate kinase isoenzyme 5, and transferrin in the PROE and of annexin V, alpha1-antitrypsin, creatine kinase, and peroxidoxin 6 in MSE compared with the other phase. Superimposition of the two-dimensional maps of MSE on those of MSU revealed the presence of heat-shock protein 27, transferrin, and alpha1-antitrypsin precursor in both endometrial tissues and uterine secretions. CONCLUSION(S): Differentially expressed proteins identified in the present study could be of relevance in endowing the endometrium with receptivity.

Derivation and characterization of two genetically unique human embryonic stem cell lines on in-house-derived human feeders.

This study describes the successful derivation of two human embryonic stem (hES) cell lines using 53 frozen and 18 fresh "slow-growing" surplus embryos, obtained from collaborating in vitro fertilization clinics, on in-house-derived human feeder layers. The cell lines have been derived by whole embryo culture followed by further expansion of manually dissected inner cell mass from the surrounding trophoectodermal cells. Immunocytochemical localization of cell surface markers like SSEA-3, SSEA-4, TRA-1-60, and TRA-1-81, staining for alkaline phosphatase and reverse transcriptase polymerase chain reaction (RT-PCR) analysis of pluripotency state markers viz. Oct-4, TERT, Nanog, Rex1, and Sox2 indicate that both cell lines possess typical features of embryonic stem cells. Both cell lines exhibit normal female karyotype after 40 passages in culture. Pluripotent nature of the cell lines was confirmed both in vitro and in vivo. Embryoid bodies, formed in suspension culture, express markers for all three lineages as indicated by RT-PCR analysis for SOX 1 (ectoderm), HAND 1 (mesoderm), AFP (endoderm), and CDX2 (trophoectoderm). Teratoma formed in vivo in severe combined immunodeficient mice revealed cells of all the three embryonic germ layers. Comparison of the STR and human leukocyte antigen profiles of these cell lines with the existing human ES cell lines indicate that they are genetically distinct. The addition of our hES cell lines contributes usefully to the globally restricted repertoire of human ES cell lines.

Endometrial modifications during early pregnancy in bonnet monkeys (Macaca radiata).

The present study was undertaken to investigate endometrial modifications that occur before embryo invasion in bonnet monkeys (Macaca radiata). These changes were analysed in luminal epithelium, glandular epithelium and stroma of endometrial functionalis on Day 6 post ovulation from pregnant and non-pregnant animals (n = 4 each) by transmission electron microscopy. Distinct features (i.e. loss of columnar shape by epithelial cells, changes in mitochondrial size and diffused apicolateral gap junctions) were observed in the luminal and glandular epithelium in pregnant animals. Stromal compaction was also observed in pregnant animals. Further, immunogold localisation studies demonstrated significantly higher expression (P < 0.05) of oestrogen receptor alpha, an oestrogen-regulated gene, in the glandular epithelium and stroma of the endometrium in pregnant animals compared with non-pregnant animals. Expression of two other genes known to be regulated by oestradiol, namely beta-actin and cyclo-oxygenase-1, were also significantly higher (P < 0.05) in the endometria of pregnant animals. These studies demonstrate marked changes in the endometrium before embryo invasion in bonnet monkeys. These studies also indicate altered oestrogenic activity in the uterine milieu before embryo invasion.

Developmental expression and cellular distribution of Mullerian inhibiting substance in the primate ovary.

Ovarian follicle formation during development and follicle maturation in adulthood are crucial determinants of female fertility and disruptions in these processes may result in subfertility or infertility. Among the several factors that are involved in ovarian physiology, Müllerian inhibiting substance (MIS) also known as anti-Müllerian hormone has emerged as an important marker to predict the follicle reserve. However, the roles of MIS in human ovarian physiology are unknown. To gain an insight into the potential roles of MIS in human ovarian differentiation during development and its regulation in adulthood, the expression profiles of MIS mRNA in the developing and adult human and monkey ovaries was examined by in situ hybridization. The results revealed that in the fetal human ovaries, MIS is specifically expressed at low levels in the granulosa cells of the developing primordial follicles; a small subset (approximately 2-3%) of oocytes express high amounts of MIS. In the adult human and monkey ovary, MIS mRNA is expressed at low levels in the primordial follicles, maximally in the primary and secondary follicles, and the expression is downregulated in the antral and atetric follicles. MIS expression is extinguished in the granulosa cells only after ovulation. These observations strongly favor the regulatory roles of MIS in folliculogenesis. MIS in the primate ovary may exert its effect during the primordial follicle formation to the terminal granulosa cell differentiation. The presence of MIS in a small subset of oocytes in the fetal ovary further points towards its additional role during fetal oocyte development.

Information, education and communication for emergency contraception.

The utilisation of the emergency contraception pills is very low both in the public and private sectors. The major reason for this under-utilisation is the lack of awareness about the method among the users or the providers. A real need arises to aware the potential users or the healthcare providers like obstetrician and gynaecologists, medical practitioners, family planning counsellors, nurses and ANMs. Wider dissemination of information, education and communication about emergency contraception relating to the proper usage, mode of action and provision is the need. The information, education and communication materials developed should always be in languages socioculturally appropriate to the target audience. Mass media like TV, newspapers and women's magazine should also be included for dissemination of messages. Service providers should be informed correctly about the method. Healthcare providers would need basic scientific information of the contents of the emergency contraception pills, mode of action, indications, contra-indications, etc. Emphasis should be put on the method for use only as an emergency or 'second chance' when a primary method is not used or has failed.

N-terminal region of progesterone receptor B isoform in human spermatozoa.

Progesterone is known to act on human spermatozoa by an unidentified membrane receptor. Previous studies have demonstrated the existence of transcripts of conventional progesterone receptor (PR) in sperm RNA; antibodies directed against the C-terminal region of the conventional PR recognize a protein in sperm extracts. The present study aimed at characterizing the sperm PR using probes unique to the N-terminal region of the PR-B isoform. PR-B transcripts that were homologous to the conventional PR were detected in sperm RNA and localized in the midpiece region. Using specific antibody against the N-terminal region of PR-B, strong immunoreactivity was observed on the acrosomal region of digitonin-treated spermatozoa; Western blot analysis revealed a single band of approximately 55 kDa. Immunogold labelling studies using the same antibody localized the protein at the inner acrosomal membrane of testicular spermatids. This antibody blocked the binding of fluorescent-tagged progesterone to digitonin-treated spermatozoa and inhibited the progesterone-mediated kinase activation. The results of the present study gives an insight to speculate that the sperm membrane PR may have homology at the N-terminal region of the conventional PR-B isoform, or the membrane PR protein may share structural motifs that allows progesterone binding and interactions with the antibodies against the conventional PR.

Enhanced expressions of endometrial tumour necrosis factor alpha and its receptors during early pregnancy in bonnet monkeys.

Tumour necrosis factor alpha (TNF-alpha), a pro-inflammatory cytokine may play an active role in stimulating inflammatory reactions during pregnancy. However, the expression of endometrial TNF-alpha has not been investigated especially during early pregnancy, a phenomenon invariably accompanied by inflammatory reaction. In the present study, the endometrial expressions of TNF-alpha and its receptors (TNFR1 and TNFR2) during early pregnancy, when the embryo lies free in the zona hatched state in the uterine lumen, were analyzed by immunohistochemistry. The endometrial expressions of TNF-alpha, TNFR1 and TNFR2 were found to be significantly up-regulated (p < 0.05) in the glandular epithelium on day 6 post-ovulation in pregnant animals. The alteration in the expression of these molecules may contribute to the induction of local inflammatory reactions during implantation.

Progesterone receptors: various forms and functions in reproductive tissues.

The unequivocal role of progesterone in a variety of events like ovulation, mammary gland development, establishment and maintenance of pregnancy etc are well established. Also the data are accumulating on its role in male reproductive events. In vertebrates and humans, the biological activity of progesterone is mediated by two progesterone receptor proteins PR-A and PR-B, that arise from the same gene and are the members of nuclear receptor superfamily of transcriptional factors. Several studies have demonstrated that the blockage of progesterone receptor using antiprogestins impairs folliculogenesis, ovulation, implantation and pregnancy. Progesterone receptor (PR), have also been detected in human spermatozoa. However, unlike the conventional PR, sperm PR was localized on the membrane and showed distinct characteristics in terms of its size. There are data to demonstrate the inhibition of progesterone driven functions such as hyperactive motility, acrosome reaction on neutralization of sperm membrane PR with specific antibodies against PR. Further significant decrease in the % of PR positive spermatozoa was observed in infertile cases as compared to the fertile men. This indicated that PR can serve as the marker to define the fertilizing potential of the spermatozoa. Recently we have also shown that the PR is expressed in human testis. This reinforced that this PR protein is an inherent testicular protein and not a secretion of accessory reproductive organs. This review compiles the major observations on the forms of the progesterone receptor in various reproductive tissues.

Characterization of a critical region in the hormone binding domain of sperm progesterone receptor.

Our previous studies have demonstrated that the ligand binding characteristics of the non-genomic sperm progesterone receptor (sPR) are different from those of the conventional progesterone receptor (PR). Unlike PR, sPR does not bind efficiently to progesterone antagonists i.e. mifepristone (RU38486), onapristone (ZK98.299) etc. The present study was undertaken to determine the molecular composition of a region that plays a critical role in the interaction of the hormone-binding domain (HBD) of sPR with progesterone and its antagonists. Detection, cloning and sequencing of the HBD region of sPR revealed its complete sequence homology to the corresponding region in the conventional PR. No nucleotide substitution/mutation/deletion, which could account for the differential antihormone binding, was observed in the HBD of sPR. The critical codon (nucleotide 3216-3218) in all three clones for the HBD of sPR was found to encode for glycine. This ruled out the possibility of steric hindrance because of the placement of amino acids with side chains at a critical position in the HBD, which may interfere in binding of sPR with antiprogestins. It is likely that the post-transcriptional modifications contribute to the differential binding characteristics of sPR. This warrants future investigations to focus more on the characterization of the mature sPR protein.

Coexistence of intracellular and membrane-bound progesterone receptors in human testis.

Progesterone and progesterone receptors (PR) play a crucial role in female reproduction, but their roles in male reproductive physiology are largely unknown. Our previous studies demonstrated the presence of a specific membrane-bound PR in mature human spermatozoa that is known to regulate important sperm functions. The present study was undertaken to determine whether there exist PR in human testis and to investigate their molecular characteristics and expression profiles. PR mRNA and protein were detected in the spermatogenic cells, Sertoli cells, and occasionally the Leydig cells. PR protein was localized in nucleus and cytoplasm of spermatogonia, primary and secondary spermatocytes, and round spermatids in a stage-specific manner. Intense PR localization was observed in stages IV and V, whereas it was low at stages I, II, and III of spermatogenesis. RT-PCR studies revealed the presence of transcripts for PR in human testis and spermatogenic cells. In accordance with the reported molecular sizes of the known isoforms of PR, two mRNA transcripts of 3.8 and 2.8 kb for PR in adult human testis and spermatogenic cell RNA were detected by Northern blot hybridization. Western blot analysis of testicular and spermatogenic cell lysates revealed two bands of 120 and 90 kDa, corresponding to the conventional PR. In these tissue lysates, an additional band of approximately 55 kDa was detected that was also observed as a single band in sperm lysates, indicating that this smaller protein may correspond to the membrane-bound PR. The membrane-bound PR protein was demonstrated on the spermatogenic cells when probed with progesterone-bound fluorescein conjugate. The results of the present study demonstrate the existence of both intracellular PR-B and PR-A mRNA and protein in the spermatogenic cells of the human testis. A membrane-bound PR was also localized in these cells. The varying levels of intracellular PR during different stages of spermatogenesis and the presence of the membrane-bound PR imply the significance of progesterone in male reproductive events such as regulation of spermatogenesis.

Morphological events in the primate endometrium in the presence of a preimplantation embryo, detected by the serum preimplantation factor bioassay.

BACKGROUND: Hormonal modulation of the endometrium towards receptivity is well established; however, the role of embryonic stimuli in modulation of the endometrium prior to implantation, especially in primates, is unknown. The aim of the present study was to evaluate the endometrial histology when the embryo was present in its vicinity prior to implantation. METHODS: Preimplantation factor (PIF) bioassay was used as a tool to detect the presence of an embryo in the uterine lumen of mated bonnet monkeys (Macaca radiata) (n=9). The control group comprised seven non-mated animals. The specificity of the PIF bioassay for the presence of an embryo was tested by studies in pregnant humans and monkeys. The effects of embryonic stimuli on the endometrial morphology were analysed by routine haematoxylin-eosin staining. The expressions of CD34, an endothelial cell marker, alpha-smooth muscle actin (alpha-SMA), a marker for blood vessel maturation, and prolactin, a marker of endometrial decidualization, were studied by immunohistochemistry. RESULTS: That PIF is embryo specific was established by its presence in sera of pregnant humans, monkeys and also in embryo culture media. Six mated bonnet monkeys were found to be PIF positive. Morphologically, the endometria from these PIF-positive animals showed the presence of the pre-epithelial plaque reaction, increased angiogenesis and stromal compaction. The significantly increased number of CD34- and alpha-SMA-positive blood vessels (P<0.05) in the endometria of PIF-positive animals indicated increased angiogenesis in response to embryonic stimuli. The endometrial expression of immunoreactive prolactin was also significantly increased (P<0.05) in the PIF-positive animals, indicating decidualization. CONCLUSIONS: Using PIF as a marker to detect early pregnancy in bonnet monkeys, we have shown that the embryo induces a pre-epithelial plaque type of reaction, increased angiogenesis and decidual reaction in the endometrium prior to implantation.

Role of progesterone in structural and biochemical remodeling of endometrium.

The endometrial response to the varying levels of ovarian steroids is exhibited as alterations in its form and function. These changes in endometrial morphology and physiology, especially those observed during the implantation window are prerequisites to support embryo attachment and invasion. However the state of endometrial receptivity to embryo results from an operative network of several molecular events triggered by estrogen, progesterone and probably some other factors, yet to be discovered. It is well established that estrogen and progesterone are the critical endocrine determinants of endometrial functions. However the precise delineation of hormone driven events and their interaction is yet to be ascertained. Several attempts have been made to understand these cascades, however most of these studies have been conducted in vitro using one or the other component of endometrial tissues. We have attempted to investigate in vivo morphological and biochemical/molecular changes in endometrium in response to neutralization of progesterone synthesis/ function in two primate animal models. In one of the models, ovariectomized rhesus monkeys, artificial menstrual cycles were simulated and subsequent effects on the _expression of various genes were investigated in presence and absence of sufficient progesterone levels. The results coincided with those observed in the endometrium of the other model, bonnet monkeys presenting normal hypothalamus-ovarian-pituitary function but displaying retarded endometrial growth due to blocked progesterone receptor. A significant decline was observed in the expression of transforming growth factor beta, transforming growth factor beta receptor, leukaemia inhibitory factor, whereas no remarkable changes were observed in the expression of estrogen receptor and progesterone receptors in response to neutralization of progesterone synthesis/function in these two animal models. Taking support from the inferences drawn from previously published in vitro studies and our data from in vivo studies conducted in these two models, we propose a hypothesis supporting a potential link between the expressions of transforming growth factor beta, leukaemia inhibitory factor, cyclooxygenases and integrins.