Factors associated with anxiety in patients attending a sexually transmitted infection clinic: qualitative survey.

We used qualitative methods to explore factors, which might explain increased anxiety in patients attending a sexually transmitted infection (STI) clinic. Twenty patients, who scored significantly for anxiety on the Hospital Anxiety and Depression Scale (HADS) attended a 20-minute interview. This explored factors contributing to their current psychological symptoms. Transcripts revealed three main themes. First were factors related to possible STIs and the clinic visit. These included health anxieties about HIV or fertility and clinic factors, including staff attitudes and clinic location. Second were factors unrelated to the clinic, including previous emotional difficulties or substance misuse. Third were issues concerning stigma, embarrassment and shame. The origins of anxiety in STI patients are multifactorial and difficult to identify during brief appointments. Despite modern clinics and attitudes, stigma and embarrassment remain prominent. Interventions to address these factors could improve psychological health in this patient group.

Human endothelial gelatinases and angiogenesis.

Endothelial cell invasion is an essential event during angiogenesis (formation of new blood vessels). The process involves the degradation of the basement membrane and the underlying interstitium. The matrix metalloproteinase (MMP) family is considered to be primarily responsible for matrix degradation. Two members of the family, gelatinase A and B play an important role in angiogenesis. This review outlines recent findings on their regulation in human endothelial cells. Latent gelatinase B is secreted from endothelial cells. This enzyme can also accumulate in the cytosol as an active enzyme, free of TIMP-1. In contrast, latent gelatinase A is constitutively secreted from the cells. Unlike other MMPs, gelatinase A activation occurs on the cell membrane and is mediated by MT1-MMP. A number of physiological activators have recently been described. These include thrombin and activated protein C, both of which activate gelatinase A independent of the MT1-MMP pathway. These new findings may lead to therapeutic interventions for the treatment of angiogenic-dependent diseases such as cancer and arthritis.

Selective matrix metalloproteinase (MMP) inhibition in rheumatoid arthritis--targetting gelatinase A activation.

The matrix metalloproteinases (MMP) are a large group of enzymes responsible for matrix degradation. They contribute to joint destruction in rheumatoid arthritis (RA) by directly degrading the cartilage and bone and indirectly promoting angiogenesis (formation of new blood vessels). Inhibition of MMPs is a primary therapeutic target in RA. However, the results of limited clinical trials performed to date are disappointing. Improvements in therapeutic benefit may be achieved by targetting specific MMPs. A subclass of the MMPs, the gelatinases, contribute directly to joint destruction as well as being vital during angiogenesis. Gelatinase A is released as a latent enzyme and must be activated to degrade the matrix. It has a unique mechanism of activation on the cell surface involving membrane-type MMP (MT-MMP). Recently, the serine protease, activated protein C (APC), has been shown to directly activate gelatinase A, without requiring MT-MMP Inhibition of APC represents a selective approach to prevent gelatinase A activation and may prove to be of therapeutic benefit in RA.

Three-dimensional collagen matrices induce delayed but sustained activation of gelatinase A in human endothelial cells via MT1-MMP.

Gelatinase A, a member of the matrix metalloproteinase (MMP) family, plays an important role during angiogenesis. It is constitutively expressed by human endothelial cells as a latent enzyme and requires activation. Thrombin is the only described physiological inducer of gelatinase A in human endothelial cells. In this study, we investigated the mechanisms of gelatinase A activation by another physiological inducer, collagen. Endothelial cells were cultured on various ECM components for 24 h and the conditioned media were assessed for gelatinase A activity using gelatin zymography. The results demonstrated that type I collagen matrix specifically activates gelatinase A after 24 h in human umbilical vein and 48 h in neonatal foreskin endothelial cells. In contrast, thrombin activated gelatinase A after only 2 h. Activation by collagen was sustained over long periods of time in culture (96 h). Unlike thrombin-induced activation, collagen required active membrane type 1-MMP (MT1-MMP) on the endothelial cell surface to activate gelatinase A. In addition, collagen-induced activation of gelatinase A was inhibited by antibodies to the integrin receptor, alpha(2)beta(1), but not alpha(3)beta(1). Our findings, that collagen can provide long-term activation of gelatinase A are likely to be relevant to endothelial cell invasion during angiogenesis.

Activated protein C directly activates human endothelial gelatinase A.

Angiogenesis (formation of new blood vessels) occurs in a number of diseases such as cancer and arthritis. The matrix metalloproteinase (MMP), gelatinase A, is secreted by endothelial cells and plays a vital role during angiogenesis. It is secreted as a latent enzyme and requires extracellular activation. We investigated whether activated protein C (APC), a pivotal molecule involved in the body's natural anti-coagulant system, could activate latent gelatinase A secreted by human umbilical vein endothelial cells (HUVEC). APC induced the fully active form of gelatinase A in a dose (100-300 nM)- and time (4-24 h)-responsive manner. The inactive zymogen, protein C, did not activate gelatinase A when used at similar concentrations. APC did not up-regulate membrane type 1 MMP (MT1-MMP) mRNA in HUVEC. In addition, the MMP inhibitor, 1, 10-phenanthroline (10 nM), was unable to inhibit APC-induced activation. These results suggested that MT1-MMP was not involved in the activation process. APC activation of gelatinase A occurred in the absence of cells, indicating that it acts directly. APC may contribute to the physiological/pathological mechanism of gelatinase A activation, especially during angiogenesis.

Preeclamptic decidual microvascular endothelial cells express lower levels of matrix metalloproteinase-1 than normals.

In preeclampsia, invasion of intrauterine decidual blood vessels by placental cytotrophoblasts is significantly reduced. This study examined the secretion of matrix metalloproteinases (MMP) by cultured human decidual endothelial cells from normal (NDEC) and preeclamptic (PEDEC) pregnancies. MMPs secreted into the culture medium were measured using zymography, Western blotting, and ELISA. Results were confirmed by Northern analysis. Phorbol myristate acetate, known to induce protease activity in other endothelial cell populations, stimulated MMP1, MMP9, and TIMP1 secretion in both NDEC and PEDEC. Neither tumor necrosis factor-alpha nor transforming growth factor-beta, both thought to have significant roles in the control of placentation, affected MMP secretion. MMP9 and TIMP1 levels were similar between the two cell types; however, MMP1 secretion was markedly different between the cell types. NDEC expressed higher levels of MMP1 under both basal (160 +/- 32 ng/10(6) cells) and stimulated (275 +/- 50) conditions compared to PEDEC (32 +/- 24 and 70 +/- 53, respectively). The lower MMP1 expression of decidual endothelial cells from preeclamptic women may inhibit endovascular invasion by cytotrophoblasts. These findings may, at least partly, explain the relative failure of trophoblasts to invade maternal decidual blood vessels in preeclamptic pregnancy.

Thrombin rapidly and efficiently activates gelatinase A in human microvascular endothelial cells via a mechanism independent of active MT1 matrix metalloproteinase.

Thrombin has been shown previously to activate gelatinase A in human umbilical vein endothelial cells. The activation is thought to be mediated by membrane-type 1 matrix metalloproteinase (MT1-MMP) on the cell surface, which generates the 62-kd intermediate and the 59-kd fully active forms. We used microvascular endothelial cells derived from human neonatal foreskin to investigate the mechanism of gelatinase A activation by thrombin. Gelatinase A was measured using zymography. Whereas activation by PMA generated both the 62-kd intermediate and the 59-kd fully active forms of gelatinase A after 24 hours, activation by thrombin produced only the 59-kd species rapidly (within 2 hours). Four findings indicate that MT1-MMP was not involved in thrombin-induced activation: (1) there was no up-regulation of MT1-MMP after 2 hours stimulation by thrombin, even though there was activation of gelatinase A; (2) the 62-kd intermediate species was never detected in response to thrombin; (3) tissue inhibitor of matrix metalloproteinase-2 completely prevented gelatinase A activation induced by PMA but not by thrombin; and (4) the metalloproteinase inhibitor 1,10-phenanthroline did not inhibit thrombin-induced activation. Together, these data demonstrate that activation of gelatinase A by thrombin is different from PMA and operating via a pathway independent of MT1-MMP. The ability of thrombin to rapidly and efficiently activate gelatinase A is likely to be a major contributing factor to its potent angiogenic activity.

Rheumatoid synovial endothelial cells secrete decreased levels of tissue inhibitor of MMP (TIMP1).

OBJECTIVES: Angiogenesis (the formation of new blood vessels) is a major component of the inflammatory pannus in rheumatoid arthritis (RA). Matrix metalloproteinase (MMP) secretion by microvascular endothelial cells is an essential step in angiogenesis. The secretion of MMP1, MMP2, MMP9, and TIMP1 by human microvascular endothelial cells derived from RA synovium (RASE) to normal synovium (NSE) and neonatal foreskin (FSE) was compared. METHODS: Confluent monolayers of endothelial cells in basal medium were pre-incubated for 24 hours in the presence or absence of phorbol myristate acetate (PMA, 100 ng/ml). MMP1 activity was measured using a spectrophotometric assay and western blotting. MMP2 and MMP9 were measured using zymography. TIMP1 was measured by enzyme linked immunosorbent assay and western blotting. RESULTS: There was little difference between the amounts of MMP2 secreted by any of the cell lines. In response to PMA both synovial cell types showed a significantly higher MMP1 and MMP9 activity compared with FSE, although there was no difference between RASE and NSE. Tumour necrosis factor alpha had minimal effect on MMP activity. There was a striking decrease in the amount of TIMP1 secreted by RASE compared with normal synovium. CONCLUSIONS: As overall MMP activity is a balance between the amount of MMP and TIMP1 present, the low levels of TIMP1 produced by RASE would shift the balance in favour of increased MMP activity by these cells. This is likely to contribute to the angiogenic potential of RASE.

Active and tissue inhibitor of matrix metalloproteinase-free gelatinase B accumulates within human microvascular endothelial vesicles.

Human gelatinase B is involved in tissue remodeling and angiogenesis. It is thought to be synthesized and rapidly secreted as an inactive precursor. In this report, we have shown that human endothelial cells accumulate active forms of gelatinase B in the cytosol. Microvascular but not macrovascular endothelial cells dramatically increased the expression of cytosolic gelatinase B in response to phorbol myristate acetate. Western blotting showed that tissue inhibitor of metalloproteinase-1 (TIMP1) was also present in the cytosol. Whereas gelatinase B was complexed with TIMP1 in the conditioned medium, it existed as a free enzyme in the cytosol, suggesting that the formation of gelatinase B and TIMP1 complex occurs after their secretion. Immunogold electron microscopy revealed that gelatinase B was localized in secretory vesicles which were especially prominent in invading pseudopodia. In contrast, TIMP1 was found throughout the cytoplasm but was not present in the gelatinase vesicles. The accumulation of intracellular activated gelatinase B, ready for rapid release, may facilitate the migration of microvascular endothelial cells during angiogenesis.

The language teaching device.

An overview is presented which seeks to describe the typical behaviours and features which characterize communicative acts between caregivers and young infants from birth through to the early stages of language acquisition. These behaviours are held to be significantly different from those which may be observed in adult-to-adult discourse. They are automatically adjusted to the received level of language development in the child and are dependent upon the parent-child relationship. It is hypothesized that these special properties of maternal communicative behaviour are crucial in enabling children to substantiate their language learning capacities. To this extent these properties may be perceived as language teaching strategies even though they are not employed with conscious didactic intent. Because these strategies apparently occur universally and with natural spontaneity in the communicative behaviour adopted by adults towards children, the term 'language teaching device' is proposed to encapsulate them. A short consideration is given to the educational implications of the language teaching device for professionals working with children and concerned with promoting language development. Particular reference is made to the very young, the impaired and the developmentally delayed.