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Biomedical subjects

N Chegini

Publications and source records attributed to N Chegini.

At least 37 records · Page 2Linked to original sources
PubMed1999

The expression, activity and regulation of granulocyte macrophage-colony stimulating factor in human endometrial epithelial and stromal cells.

The expression of granulocyte macrophage-stimulating factor (GM-CSF) and GM-CSF receptors in the human endometrium suggests an autocrine/paracrine role for GM-CSF in this tissue. Using primary cultures of isolated endometrial glandular epithelial and stromal cells, the present study examined: (i) the cell specific expression of GM-CSF and GM-CSF receptor mRNA and protein; (ii) direct action of GM-CSF on the rate of DNA synthesis and cell proliferation; and (iii) regulation of GM-CSF expression through its interaction with transforming growth factor (TGF)-beta1 in these cells. Quantitative reverse transcription-polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay and immunocytochemistry indicates that glandular epithelial and stromal cells express GM-CSF, GM-CSF alpha and GM-CSF beta receptor mRNA and protein. The epithelial cells express a significantly higher level of GM-CSF mRNA than stromal cells while both types produce low concentrations of protein. At 0.01-100 ng/ml GM-CSF did not have a significant effect on the rate of [3H]-thymidine incorporation or proliferation of epithelial and stromal cells. However, GM-CSF (1 ng/ ml) up-regulates its own protein expression, but does not effect TGF-beta1 mRNA protein expression in epithelial and stromal cells, and actually inhibits the cell-associated TGF-beta1 protein in stromal cells (P<0.05). At 1 ng/ ml TGF-beta1 up-regulates its own mRNA and protein expression in epithelial and stromal cells (P<0.05), with no significant effect on GM-CSF expression. Co-treatment of the cells with GM-CSF + TGF-beta1 resulted in an increased production of GM-CSF protein as well as TGF-beta1 mRNA and protein expression by epithelial and stromal cells, compared with untreated controls (P<0,001). In conclusion, the results suggest that GM-CSF is not a mitogenic factor for endometrial glandular epithelial and stromal cells, however, in an interactive manner with TGF-beta1 it regulates its own and the expression of TGF-beta1.

Adult↗
PubMed1999

An inverse relation between the expression of tumor necrosis factor alpha (TNF-alpha) and TNF-alpha receptor in human endometrium.

PROBLEM: To determine whether the expression of tumor necrosis factor (TNF-alpha) correlates with TNF-alpha receptor expression in human endometrium. METHOD OF STUDY: A multiprimer synthetic cDNA standard template containing complimentary sequences for several cytokines including TNF-alpha and TNF-alpha receptor type 2 was constructed and used in quantitative reverse transcription polymerase chain reaction (Q-RT-PCR). RESULTS: Endometrium from proliferative phase of the menstrual cycle expresses higher levels of TNF-alpha mRNA (2.35 +/- 0.2 x 10(5) copies/microg of total cellular RNA) than secretory phase ([1.3 +/- 0.08 x 10(5) copies] P < 0.05), with a significant reduction during menses (1.2 +/- 0.1 x 10(4) copies) and postmenopausal period (8.1 +/- 1.6 x 10(4) copies [P < 0.05]). In contrast, TNF-alpha type 1 receptor mRNA expression was higher in endometrium from the secretory phase (6.6 +/- 0.6 x 10(7) copies) compared to the menses (5.1 +/- 0.5 x 10(6) copies), proliferative phase (1.9 +/- 0.1 x 10(6) copies) and postmenopausal period (5.8 +/- 0.7 x 10(4) copies [P < 0.05]). Comparatively, TNF-alpha receptor type 2 is expressed 10 to 100 fold higher in the endometrium than TNF-alpha (P < 0.05). CONCLUSION: The data confirm that human endometrium expresses TNF-alpha; and provide the first evidence that TNF-alpha expression is inversely related to TNF-alpha type 1 receptor expression during the menstrual cycle. Such an inverse relation between TNF-alpha and TNF-alpha receptor expression may provide a regulatory mechanism necessary to overcome the detrimental effect of high levels of TNF-alpha on various endometrial cell types.

Actins↗
PubMed1999

The expression of granulocyte macrophage-colony stimulating factor (GM-CSF) and receptors in human endometrium.

PROBLEM: To determine the temporal and spatial expression of granulocyte macrophage-colony stimulating factor (GM-CSF) and GM-CSF alpha and beta receptor mRNA and protein in human endometrium. METHOD OF STUDY: The endometrial expression of GM-CSF and GM-CSF receptor mRNA and protein was determined using competitive quantitative reverse transcription polymerase chain reaction (Q-RT-PCR), in situ hybridization, and immunohistochemistry. RESULTS: Endometrium expresses GM-CSF and GM-CSF alpha receptor mRNA with maximal expression occurring during the mid-secretory phase (21.1 +/- 4.2 and 32.2 +/- 7.7 x 10(6) mRNA copies/microg total RNA) compared to the proliferative phase (1.46 +/- 0.4 and 7.5 +/- 0.5 x 10(6) copies) of the menstrual cycle, with a significant reduction (0.67 +/- 0.1 and 1.7 +/- 0.2 x 10(6) mRNA copies) during the post-menopausal period (P < 0.05). The endometrium expresses a significantly lower level of GM-CSF beta receptor mRNA (approximately 0.01 x 10(5) mRNA copies). Endometrial luminal and glandular epithelial cells are the primary site of GM-CSF mRNA and protein expression, while arteriole endothelial, stromal, and inflammatory cells are the primary site of GM-CSF alpha receptor protein. GM-CSF beta receptor protein has a similar cellular distribution as GM-CSF. CONCLUSION: Temporal and spatial expression of GM-CSF and GM-CSF receptors in human endometrium during the menstrual cycle suggests that epithelial-derived GM-CSF in an autocrine/paracrine manner may influence various endometrial biological activities, local inflammatory response, and macrophage survival.

Adult↗
PubMed1999

Regulation of transforming growth factor-beta1 expression by granulocyte macrophage-colony-stimulating factor in leiomyoma and myometrial smooth muscle cells.

Human myometrium and leiomyomas express granulocyte macrophage-colony-stimulating factor (GM-CSF), transforming growth factor-beta (TGFbeta), and their receptors. Overexpression of TGFbeta and, to a limited extent, GM-CSF has been associated with tissue fibrosis throughout the body, including leiomyomas. The objective of the present study was to determine the action of GM-CSF on leiomyoma and myometrial smooth muscle cells (LSMC and MSMC) and examine whether the action of GM-CSF is mediated through the induction of TGFbeta1 expression. Using competitive quantitative RT-PCR and enzyme-linked immunosorbent assay, we found that LSMC express significantly higher GM-CSF messenger ribonucleic acid (mRNA; 0.6 +/- 0.1 x 10(3) copies of mRNA/microg total RNA) and protein (0.75 +/- 0.2 ng/mL) than MSMC (0.5 +/- 0.1 x 10(2) copies of mRNA and 0.45 +/- 0.07 ng/mL protein; P < 0.05). In addition, LSMC expressed significantly higher TGFbeta1 mRNA (1.6 +/- 0.3 x 10(4) copies of mRNA/microg total RNA) than MSMC (2.4 +/- 0.4 x 10(3) copies) and synthesized and secreted more TGFbeta1 protein (1.7 +/- 0.2 vs. 0.5 +/- 0.02 ng/mL); whereas MSMC contained more cell-associated TGFbeta1 (56.2 +/- 1.2 ng/mL) than LSMC (35.2 +/- 1.2 ng/mL; P < 0.05). We found that GM-CSF (0.01-100 ng/mL) has limited mitogenic activity for LSMC but not for MSMC determined by the rate of [3H]thymidine incorporation and cell proliferation assay. However, GM-CSF at 1 ng/mL increased its own production, the expression of TGFbeta1 mRNA, the cell-associated TGFbeta1 protein content in both cell types, and TGFbeta1 released into the culture-conditioned medium of LSMC (P < 0.05). TGFbeta1 also increased its own mRNA and protein expression, but had no effect on cell-associated TGFbeta1 in both cell types (P < 0.05). Cotreatment of LSMC and MSMC with GM-CSF and TGFbeta1 induced changes similar to those produced by GM-CSF in both cells. In conclusion, our data suggest that GM-CSF is not a mitogen for MSMC and LSMC, but it regulates its own expression and the expression of TGFbeta1 by these cells, a regulatory interaction that may account for the GM-CSF-induced tissue fibrosis that occurs in leiomyomas.

Culture Media, Conditioned↗
PubMed1997

Detection of ebaf, a novel human gene of the transforming growth factor beta superfamily association of gene expression with endometrial bleeding.

Human endometrium is unique since it is the only tissue in the body that bleeds at regular intervals. In addition, abnormal endometrial bleeding is one of the most common manifestations of gynecological diseases, and is a prime indication for hysterectomy. Here, we report on a novel human gene, endometrial bleeding associated factor (ebaf), whose strong expression in endometrium was associated with abnormal endometrial bleeding. In normal human endometrium, this gene was transiently expressed before and during menstrual bleeding. In situ hybridization showed that the mRNA of ebaf was expressed in the stroma without any significant mRNA expression in the endometrial glands or endothelial cells. The predicted protein sequence of ebaf showed homology with and structural features of the members of TGF-beta superfamily. Fluorescence in situ hybridization showed that the ebaf gene is located on human chromosome 1 at band q42.1. Thus, ebaf is a novel member of the TGF-beta superfamily and an endometrial tissue factor whose expression is associated with normal menstrual and abnormal endometrial bleeding.

Adult↗
PubMed1997

Expression of alpha-smooth muscle actin, TGF-beta 1 and TGF-beta type II receptor during connective tissue contraction.

Closure of rat mesenteric perforation is considered to occur by connective tissue contraction, a process that has been shown to be stimulated by transforming growth factor-beta 1. In the present study, we assessed the expression of alpha-smooth muscle actin during closure by quantitative-reverse transcription-polymerase chain reaction and in situ hybridization. The expression of transforming growth factor-beta 1 and transforming growth factor-beta type II receptor was also estimated in mesenteric membranes and free peritoneal cells after wounding. A larger expression of alpha-smooth muscle actin was seen around the wound edges compared to unwounded tissue. Both alpha-smooth muscle actin and transforming growth factor-beta type II receptor were expressed during Days 0, 3, 5, 7, and 10. The expression of alpha-smooth muscle actin on Day 5 was > 100 times higher than on Day 0. Transforming growth factor-beta 1 was expressed in both membranes and free peritoneal cells of unoperated control animals but down-regulated after wounding, a finding that has not been reported previously. It reappeared on Days 7 and 10 in free peritoneal cells but not in perforated membranes. The enhanced expression of alpha-smooth muscle actin and down-regulation of transforming growth factor-beta 1 expression after wounding appears to be important phenomena in tissue contraction and repair.

Actins↗
PubMed1997

Extracellular-matrix gene expression during mouse submandibular gland development.

Early morphogenesis of mouse submandibular glands begins on late day 11 of fetal development when the epithelium begins to bud from the surrounding mandibular mesenchyme. Using total RNA collected from fetal BALB/c submandibular glands, steady-state levels of mRNA expression for extracellular matrix molecules were measured using quantitative competitive reverse transcription-polymerase chain reaction (RT-PCR). By comparing the PCR amplification products of both the cellular mRNA and a synthetic template, pMATRIX, it was possible to measure the direct expression of collagens alpha2(I), alpha1(III), alpha1(IV), fibronectin, laminin B2, elastin and lysyl oxidase genes. There was an observed trend for an increasing concentration of collagen alpha2(I), collagen alpha1(III) and lysyl oxidase mRNA molecules per cell on day 16 of development. The relative abundance of elastin mRNA was detectable only on day 16. Fibronectin and laminin B2 were more constitutively present but had their highest copy number per cell on day 16. The presence of extracellular-matrix protein was confirmed by immunohistochemistry using day-16 fetal glands and adult glands. With the construction of the pMATRIX supertemplate and the advent of quantitative, competitive RT-PCR technology, it has been possible to measure small changes in the steady-state concentrations for extracellular-matrix mRNA during salivary gland development.

Animals↗
PubMed1997

Detection of alterations in the levels of neuropeptides and salivary gland responses in the non-obese diabetic mouse model for autoimmune sialoadenitis.

The salivary glands of non-obese diabetic (NOD) mice and BALB/c controls were evaluated for the stimulatory effects of the following neuropeptides; substance P (SP), vasoactive intestinal polypeptide (VIP), and neuropeptide Y (NPY). Injection of either of the three neuropeptides in combination with the muscarinic-cholinergic agonist pilocarpine increased saliva flow rates in BALB/c mice while there was no observable augmentation to flow rates in pre-diabetic or diabetic NOD mice. Small increases in protein content of the stimulated saliva were observed in the BALB/c group of animals with the injection of any of the above neuropeptides in combination with pilocarpine. In pre-diabetic NOD animals, only VIP and NPY increased the protein content-ratio above pilocarpine alone. Radioimmunoassay determination of neuropeptide concentrations in the submandibular and parotid glands revealed reduced levels of SP with diabetes onset as compared with pre-diabetic NOD or BALB/c mice. The levels of NPY were similar between BALB/c and NOD animals except in the pre-diabetic parotid gland where NPY concentrations were 1.3-fold greater. On the other hand, VIP concentrations were substantially reduced in the submandibular gland of NOD mice, while in the parotid gland neuropeptide levels were evaluated 3.8-fold relative to BALB/c controls. Immunohistochemical staining of the parotid and submandibular glands for SP revealed primarily ductal cell staining which was reduced with diabetes onset in NOD animals. These findings further define the sialoadenitis observed in NOD mice to be due, in part, to a general loss of neurotransmitter responsiveness on the part of salivary gland cells.

Animals↗
PubMed1997

Differential expression of matrix metalloproteinases and their tissue inhibitors in leiomyomata: a mechanism for gonadotrophin releasing hormone agonist-induced tumour regression.

Tissue remodelling involving extracellular matrix (ECM) turnover plays a major role in leiomyoma growth and regression, regulated by the combined action of matrix metalloproteinases (MMPs) and the tissue inhibitors of MMPs (TIMPs). We postulated that leiomyomata express MMP and TIMP mRNA and protein, and their expression is inversely regulated during tumour growth and gonadotrophin releasing hormone agonist (GnRHa)-induced regression. We therefore examined the expression of mRNA and protein for MMPs (interstitial collagenase, MMP-1; gelatinases, MMP-2 and MMP-9; and stromelysin, MMP-3) and TIMPs (TIMP-1 and TIMP-2) in leiomyoma and matched unaffected myometrium from GnRHa (lupron)-treated and untreated patients. Reverse transcription-polymerase chain reaction (RT-PCR) and restriction enzyme analysis revealed that leiomyomata and myometrium expressed MMP-1, -2, -3 and -9, as well as TIMP-1 and -2 mRNA. Quantitative RT-PCR indicated that leiomyomata and myometrium during the secretory phase of the menstrual cycle expressed higher levels of MMP and TIMP mRNA compared to the proliferative phase (P < 0.05), with low to undetectable levels of MMP-1, -2 and -3 mRNA in the tumours. GnRHa therapy induced an overall reduction in MMP and TIMP mRNA expression in both leiomyomata and myometrium, but a significant decrease in TIMP-1, and an increase in MMP mRNA expression compared with untreated tumours (P < 0.05). Immunohistochemically, MMP-1, -2, -3 and -9 and TIMP-1 and -2 proteins were localized in leiomyomata and myometrial smooth muscle cells, arteriole wall and connective tissue fibroblasts, with an overall increase in MMP and a decrease in TIMP staining intensity in GnRHa-treated groups. The results suggest that MMP and TIMP expression in leiomyoma and myometrium are hormonally regulated, and that GnRHa-induced tumour regression is accompanied by an increase in MMP expression with a concomitant decrease in TIMP-1 expression, which may potentially provide an environment favouring ECM degradation.

Adult↗
PubMed1997

The expression of transforming growth factor-beta s and TGF-beta receptor mRNA and protein and the effect of TGF-beta s on human myometrial smooth muscle cells in vitro.

In this study we investigated the expression of transforming growth factor-beta (TGF-beta) isoform and TGF-beta receptor mRNA and protein, and the effect of TGF-beta 1-3 on the rate of DNA synthesis and proliferation of human myometrial smooth muscle cells in vitro. To determine these, we utilized primary cultures of myometrial smooth muscle cells, standard and competitive quantitative reverse transcription-polymerase chain reaction (RT-PCR), immunocytochemistry, enzyme-linked immunoassay, radioreceptor assay, [3H] thymidine incorporation and cell proliferation assay. Standard RT-PCR and immunocytochemistry revealed that myometrial smooth muscle cells express TGF beta 1-3 and TGF-beta type I-III receptor (TGF-beta R) mRNA and protein. Quantitative RT-PCR, using an external synthetic RNA standard, indicated that the cells express 10 copies/cell of TGF-beta 1 and TGF-beta 2, less than one copy/cell of TGF-beta 3 and TGF-beta type IR, three copies/cell of type IIIR, and > 200 copies/cell, of TGF-beta type IIR mRNA. The cells also synthesized and released TGF-beta 1 at the rate of 7.8 +/- 0.7 ng/10(6) cells, of which 1.4 +/- 0.2 ng/10(6) cells was in an active form. The rate of [3H] thymidine incorporation or proliferation of subconfluent quiescent smooth muscle cells was not altered by TGF-beta s (0.1-10 ng/ml) under serum-free conditions, nor in the presence of 10% fetal bovine serum (FBS). TGF-beta 1-3 at 0.25-0.5 ng/ml in the presence of 2% FBS, which induces half maximal stimulation of these cells, stimulated the rate (P < 0.05), whereas at higher doses it reduced the rate of [3H]-thymidine incorporation compared to the controls. The effect of TGF-beta was partially reversible using neutralizing antibodies specific to TGF-beta 1, TGF-beta 2 (10 micrograms/ml) or TGF-beta 3 (3-6 micrograms/ml). TGF-beta s had no significant effect on cell proliferation determined by cell counting. The data indicate that human myometrial smooth muscle cells express the necessary components of the TGF-beta system, suggesting an autocrine/paracrine role for TGF-beta s in myometrium.

Animals↗
PubMed1997

Inhibition of transforming growth factor-beta 1 alters the growth, anchor-dependent cell aggregation and integrin mRNA expression in human promonocytes: implications for endometriosis and peritoneal adhesion formation.

Transforming growth factor beta (TGF-beta) is a major secretory product of macrophages which, through autocrine/paracrine pathways, play a central role in normal reproductive tissues as well as in disorders such as endometriosis and intraperitoneal adhesion formation. Using TGF-beta antisense oligonucleotides and U937 cells (a promonocytic human cell line) as an in-vitro model, the present study examined the autocrine mediated action of TGF-beta 1 on proliferation, anchor-dependent and -independent cell aggregation and expression of several mRNAs of cell surface adhesion molecules including integrins and platelet-endothelial cell adhesion molecule (PECAM-1). Northern blot analysis and enzyme-linked inmmunosorbent assay (ELISA) revealed that treatment with TGF-beta 1 antisense, but not sense or nonsense oligomers, in a dose-dependent manner (0.1-10 microM) down-regulated the expression of TGF-beta 1 mRNA and protein to undetectable amounts at the highest antisense concentration. TGF-beta 1 antisense at < 1 mM slightly increased, while at > 3 microM significantly inhibited, the rate of DNA synthesis and proliferation of these cells (P < 0.05). Treatment with TGF-beta 1 antisense promoted cell aggregation under anchor-independent culture conditions (plastic dishes), while it suppressed colony formation under anchor-dependent culture conditions (soft agar assay). U937 cells expressed alpha 2, alpha 3, alpha 4, alpha 5, alpha 6, beta 1 and beta 2 integrin mRNA and PECAM-1 mRNA, while alpha v, beta 3 and beta 5 integrin mRNA was undetectable. The relative amount of alpha 2, alpha 3, alpha 4, alpha 6, beta 1 and beta 2 integrin and PECAM-1 mRNA expression were down-regulated in a dose-dependent manner after TGF-beta 1 antisense treatment, while alpha 5 integrin mRNA expression was up-regulated, although it was undetectable at 10 microM antisense. In contrast, TGF-beta 1 antisense up-regulated beta 3 mRNA expression with maximal effect occurring at 10 microM. These results provide evidence that the autocrine loop of monocyte/macrophage-derived TGF-beta 1 action is essential for regulation of growth, aggregation and the expression of adhesion molecules by these cells. We propose that in disorders such as endometriosis and peritoneal fibrous adhesions, significantly higher numbers of tissue macrophages with the capacity to express excess TGF-beta 1 yield an environment able to promote cell-cell and cell-matrix interactions, and thus lead to further complications from these abnormalities. We are currently investigating whether site-specific inhibition of TGF-beta using antisense strategy is a useful tool for management of these lesions, particularly after their post-surgical removal.

Base Sequence↗
PubMed1997

Endotoxin and particulate matter on surgical gloves.

Because of the continual need to protect of health care workers, gloves are increasingly used. Most gloves purchased are powdered. Besides having deleterious effects on wound healing, glove powder can act as a vehicle for latex allergens, endotoxin, and possibly bacteria. Few tested gloves had undetectable levels of endotoxin, and only one was free from particulate matter. Since powder particles can become airborne and are thus easily spread, concerns for health care professionals and patients arise. To reduce risks for exposure, glove-selection criteria must include low or undetectable levels of latex allergens, endotoxin, and particulate matter.

Endotoxins↗
PubMed1997

The role of growth factors in peritoneal healing: transforming growth factor beta (TGF-beta).

Processes that result in either normal peritoneal tissue repair of fibrous adhesion formation have until recently been largely unexplored at the molecular level. Our group is investigating the molecular events underlying peritoneal healing and hypothesizes that peptide growth factors, cytokines, and their receptors, which are expressed by various cell types at the site of injury and are present in the peritoneal fluid, play key roles in regulating tissue repair processes. This regulation is highly complex, involving the individual action of and/or synergistic interactions among many substances. These include various members of the growth factor family, such as transforming growth factors alpha and beta (TGF-alpha and TGF-beta), and of the cytokine family. These growth factors and cytokines are synthesized and released by activated macrophages in the peritoneal fluid and in the wound and by other major cell types in the wound, suggesting that they have a role in an autocrine/paracrine mechanism. For normal peritoneal healing to occur, the availability of these signaling substances must be optimal, precise, and synchronized. Inhibition, interruption, or excess expression of these signals seems to be responsible for failure in normal healing, either impairment (nonhealing) or excess tissue formation (adhesion development). Evidence of the key role of TGF-beta in peritoneal healing and adhesiogenesis falls into four main categories: 1) the characteristics of TGF-beta in other settings; 2) the presence and 3) activity of TGF-beta and/or its receptors in peritoneal wounds and fluid; and 4) the effects of the application of excess TGF-beta and anti-TGF-beta antibody on adhesion formation. TGF-betas are chemotactic for fibroblasts and inflammatory cells and promote cell proliferation and differentiation and angiogenesis. They also regulate the expression of various components of extracellular matrix. In mice, subcutaneous TGF-beta induces the formation of granulation tissue, and in several animal models and in humans, excess TGF-beta activity has been linked to the development of kidney and liver fibrosis. TGF-betas and their receptors are expressed by various cells in peritoneal wounds and fluid and are present at higher levels in injured compared with uninjured tissues. In vitro studies in peritoneal wounds and fluid show that TGF-beta 1 significantly upregulates its own expression and the expression of several extracellular matrix components and of tissue inhibitors of matrix metalloproteinases (TIMPs) but downregulates the expression of matrix metalloproteinases (MMPs). Following uterine horn injury, rats given TGF-beta daily for five days developed adhesions in significantly greater number and severity than did untreated controls. Although anti-TGF-beta neutralizing antibody in rats failed to significantly reduce adhesion formation, it did reduce cellularity of fibrous tissue. Antisense oligonucleotides to TGF-beta effectively blocked macrophage expression of TGF-beta, indicating the possible use of this technique in adhesion prevention. Another potential clinical application of some of our findings includes targeted delivery of an anti-TGF-beta preparation by means of a suitable biodegradable barrier during the first five to seven days following peritoneal injury.

Animals↗
PubMed1997

Adhesions: pathogenesis and prevention-panel discussion and summary.

This article summarizes the discussions of the faculty and chairpersons on four major topics on postsurgical adhesions examined at the symposium, "Adhesions: Pathogenesis and Prevention". These topics are: 1) clinical significance; 2) pathogenesis; 3) research status and directions; and 4) recommendations for reduction or prevention. Abdominal postsurgical adhesions develop following trauma to the mesothelium, which is damaged often by surgical handling and instrument contact, foreign materials such as sutures and glove dusting powder, desiccation, and overheating. Postoperative adhesions occur after most surgical procedures and can result in serious complications, including intestinal obstruction, infertility, and pain. A long-term and unpredictable problem, postoperative adhesions impact the surgical workload and hospital resources, resulting in considerable health care expenditures. Although understanding of the pathogenesis of adhesions has improved recently, the molecular mechanisms involved continue to be delineated. Adhesions result from the normal peritoneal wound healing response and develop in the first five to seven days after injury. Adhesion formation and adhesion-free re-epithelialization are alternative pathways, both of which begin with coagulation which initiates a cascade of events resulting in the buildup of fibrin gel matrix. If not removed, the fibrin gel matrix serves as the progenitor to adhesions by forming a band or bridge when two peritoneal surfaces coated with it are apposed. The band or bridge becomes the basis for the organization of an adhesion. Protective fibrinolytic enzyme systems of the peritoneum, such as the plasmin system, can remove the fibrin gel matrix. However, surgery dramatically diminishes fibrinolytic activity. The pivotal events determining whether the pathway taken is adhesion formation or re-epithelialization are therefore the apposition of two damaged surfaces and the extent of fibrinolysis. Research in postsurgical adhesion formation and prevention abounds in a variety of avenues of investigation, including: 1) identification on a molecular level of the components involved in adhesiogenesis and their interactions; 2) clarification of the role of fibrin and fibrinolysis in adhesion formation; 3) standardization of design in preclinical and clinical studies of adhesion formation and prevention; 4) delineation of the relationship between adhesion formation and adhesive complications; and 5) elucidation of efficient, site-specific methods of prophylactic drug delivery. Currently, it seems logical to focus preventive research on development of barriers, fibrinolytic drugs, and selected agents such as phospholipids. The major strategies for adhesion prevention or reduction are adjusting surgical practice and applying adjuvants. Surgeons should adjust their major practices by: 1) becoming aware of the potential adhesive complications of a procedure; 2) minimizing the invasiveness of surgery; and 3) minimizing surgical trauma, ischemia, exposure to intestinal contents, introduction of foreign material into the body, and the use of talc- or starch-containing gloves. Available adjuvants include a newly developed by hyaluronic acid-phosphate-buffered saline solution applied intraoperatively to protect peritoneal surfaces from indirect surgical trauma and three mechanical barriers. One of these, a bioresorbable membrane consisting of hyaluronic acid and carboxymethylcellulose, has demonstrated efficacy and safety in both general and gynecological surgery. The other two barriers, one made of expanded polytetrafluoroethylene and one developed from oxidized regenerated cellulose, are indicated only for use in gynecological surgery.

Humans↗
PubMed1996

Contraception potential of neem oil: effect on pregnancy success in the mouse.

PURPOSE: The aim of this study was to find out the role and mechanism of action of neem oil as a postcoital fertility blocker in mouse. METHODS: Female mice were injected with neem oil (20 or 40 microliters) surgically into each uterine horn on day 2 postcoitum (pc). Both the uterine horns of each mouse were injected. Arachis oil served as vehicle control. Pregnancy success was determined by the number of implanted embryos on day 8 pc and the number of live fetuses in the uteri on day 18 pc. Transforming growth factor-alpha (TGF alpha), epidermal growth factor (EGF), and epidermal growth factor receptor (EGFR) were immunolocalized in the paraffin-embedded sections of the uteri at 0600 hr on day 5 pc. The unimplanted embryos were assessed in the uteri at 2000 hr on day 5 pc. Uterine secretions were assessed for the leukocytes infiltration on day 4 through day 8 pc. RESULTS: The number of implantation sites on day 8 pc and the number of live fetuses on day 18 pc were lower in the neem oil-treated animals compared to their respective control animals at both the concentrations of neem oil (20 and 40 microliters/uterine horn). Neem oil also caused resorption of some embryos between day 8 pc and day 18 pc. In neem oil-treated mice, EGFR immunostaining decreased in the luminal and glandular epithelium and increased in the stroma as determined at 0600 hr on day 5 pc. Uterine secretions on day 4 through day 6 pc from the neem oil-treated mice showed massive leukocyte infiltration. Unimplanted preimplantation embryos, underdeveloped, degenerated, or at blastocyst stage, were recovered from the uteri after flushing at 2000 hr on day 5 pc from the neem oil-treated animals. A number of retrieved unimplanted embryos showed the direct attachment of the leukocytes to their zona pellucida. It is believed that the secretions of these leukocytes might be responsible for the underdevelopment of the early embryos and hence inhibition of implantation. The exact interaction of these leukocytes and their secretions with the early embryos is under investigation. CONCLUSIONS: Postcoital intrauterine treatment of neem oil during preimplantation period causes fertility block in mouse by lowering the EGFR localization in the luminal and glandular epithelium, by causing massive leukocytes infiltration into the uteri, by degenerating the early embryos, and by causing the postimplantation embryonic resorptions in the uteri. The possible mechanism of action of neem oil is discussed.

Animals↗
PubMed1996

Immunolocalization of eicosanoid enzymes and growth factors in human myometrium and fetoplacental tissues in failed labor inductions.

OBJECTIVE: To investigate the correlation between myometrial-derived eicosanoids and growth factors during the onset of parturition. METHODS: Myometrial samples were obtained from patients who were delivered by cesarean for failed induction or abnormal fetal heart rate tracings but who experienced normal labor progression until the occurrence of the abnormal tracing. Placentas and fetal membranes were obtained from patients with normal labor, no labor, and failed labor progression. The tissues were processed and sections were immunostained for cyclooxygenases, prostacyclin synthetase (PGI2-S), thromboxane A2 synthetase (TXA2-S), 5-lipoxygenase, epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha), and EGF receptor, using specific antibodies directed against these molecules. RESULTS: Myometrial and fetoplacental tissues from women with normal labor, no labor, and failed labor contain immunoreactive cyclooxygenases, 5-lipoxygenase, TXA2-S, PGI2-S, EGF, TGF-alpha, and EGF receptor. However, their immunostaining intensity, with the exception of EGF receptor, decreased substantially in myometrium from women with failed labor induction compared with those having normal labor progression. No difference was noted in the immunostaining intensity of growth factors and eicosanoid enzymes in the fetoplacental membranes from these patients, except for cyclooxygenases, which were prominent in fetal membranes from normal labor compared with failed labor and no labor. CONCLUSION: Myometrial-derived eicosanoids and growth factors may be important in processes of parturition because reduction in their production in the myometrium is correlated with failed labor induction. Because of the regulatory action of growth factors in eicosanoid biosynthesis in uterine and fetoplacental tissues, EGF/TGF-alpha may indirectly influence the process of parturition by regulating eicosanoid production in the myometrium.

Eicosanoids↗
PubMed1996

Ovarian intrabursal administration of transforming growth factor beta 1 inhibits follicle rupture in gonadotropin-primed mice.

We hypothesized that over-expression and/or activation of latent transforming growth factor betas (TGF betas) by various ovarian cell types may lead to disturbances in ovulation and fertilization. To test this hypothesis, active TGF beta ranging from 1 to 500 ng was administered intrabursally into the ovaries of gonadotropin-primed mice, and the rates of ovum recovery and fertilization were determined. Furthermore, the presence and cellular distribution of endogenous TGF betas and TGF beta type I and type II receptors were determined immunohistochemically in the ovarian tissues of TGF beta 1-treated and untreated groups. The total number of ova recovered per ovary from ovaries treated as pairs or treated singly with TGF beta 1 at 1 to 10 ng/ovary was similar to that from controls, whereas the number recovered from ovaries treated as pairs or singly with 50 or 100 ng of TGF beta 1 per ovary was significantly lower than the number from respective controls (p < 0.05, 0.001). The number of ova recovered per ovary from ovaries treated as pairs or singly with TGF beta 1 at 200 or 500 ng/ovary was similar to the number of ova obtained from ovaries treated with TGF beta 1 at 100 ng/ovary. The rate of in vitro fertilization was low in ova recovered from ovaries treated with 50, 100, 200, and 500 ng/ovary of TGF beta 1, compared to that in ova from untreated ovaries. Histologically, the TGF beta 1-treated ovaries contained large numbers of unruptured follicles, whereas untreated ovaries contained large numbers of corpora lutea. Immunohistochemically, the endogenous TGF beta 1 and TGF beta 2 was localized in theca, granulosa, and luteal cells, without a substantial difference in intensity or distribution, in both TGF beta 1-treated ovaries and in controls. Theca cells were the primary site of immunoreactive TGF beta protein. TGF beta type I and type II receptors were also present in these cells, and their relative immunoreactive intensity was considerably reduced, particularly in granulosa cells in TGF beta 1-treated ovaries compared to controls. The results support our hypothesis and suggest that TGF betas play an important regulatory role in follicular development, oocyte maturation, and the ovulatory process.

Animals↗