Review of spectral domain-enhanced depth imaging optical coherence tomography of tumors of the retina and retinal pigment epithelium in children and adults.

Background: Spectral domain (SD) enhanced depth imaging optical coherence tomography (EDI‑OCT) is a useful tool for anatomic, cross‑sectional imaging of retinal conditions. Aims: The aim was to identify characteristic patterns of retinal and retinal pigment epithelial tumors on EDI‑OCT in children and adults. Settings and Design: Retrospective review. Materials and Methods: Analysis of published reports and personal observations using office‑based EDI‑OCT for adults and portable hand‑held SD OCT for infants and children. Results: Using EDI‑OCT, retinal tumors such as small retinoblastoma, astrocytic hamartoma, and hemangioblastoma arose abruptly from the retina, immediately adjacent to normal retina. Small exophytic retinoblastoma and retinal hemangioblastoma showed the full‑thickness, homogeneous retinal disorganization with surrounding normal retina “draping” over the margins. Retinoblastoma occasionally had intralesional cavities and surrounding subretinal fluid. Hemangioblastoma often had adjacent intraretinal edema and subretinal fluid. Astrocytic hamartoma arose within the nerve fiber layer and sometimes with a “moth‑eaten” or cavitary appearance. Retinal pigment epithelial (RPE) lesions such as congenital hypertrophy of RPE appeared flat with shadowing, occasional subretinal cleft, and abrupt photoreceptor loss. Congenital simple hamartoma showed an abrupt elevation from the inner retina with crisp, dark posterior shadowing. Combined hamartoma of the retina/RPE showed vitreoretinal traction causing “sawtooth mini‑peak” or gently “maxi‑peak” folding of the retina. RPE adenoma often produces remote macular edema or epiretinal membrane and the tumor has an irregular, “rugged” surface with deep shadowing. Conclusions: Enhanced depth imaging optical coherence tomography shows characteristic patterns that are suggestive of certain retinal and RPE tumors.

Review of spectral domain enhanced depth imaging optical coherence tomography of tumors of the choroid.

Background: Spectral domain enhanced depth imaging optical coherence tomography (EDI‑OCT) can provide anatomic localization of intraocular tumors. Aims: The aim was to identify topographical and intrinsic patterns of choroidal tumors on EDI‑OCT. Settings and Design: Retrospective review. Materials and Methods: Analysis of published reports and personal observations using office based EDI‑OCT. Results: Using EDI‑OCT, choroidal nevus displayed a smooth, dome‑shaped topography with overlying retinal pigment epithelium alterations, drusen, and occasional subretinal cleft demonstrating photoreceptor loss. Small choroidal melanoma showed smooth, moderately dome‑shaped topography, commonly with overlying shallow subretinal fluid that often depicted “shaggy” photoreceptors. Choroidal metastasis showed a minimally “lumpy, bumpy” surface topography and with overlying subretinal fluid and shaggy photoreceptors. Choroidal hemangioma showed a smooth, dome‑shaped topography, with expansion of the affected small, medium, and large choroidal vessels. Choroidal lymphoma showed varying topography with increasing tumor thickness as “flat, rippled, or undulating (seasick)” surface. Choroidal osteoma displayed a smooth undulating surface with visible intralesional horizontal lines suggestive of bone lamellae and occasional horizontal and vertical tubules with intralesional “spongy” flecks. Choroidal melanocytosis appeared as uniformly thickened choroid with increased stromal density surrounding the normal choroidal vascular structures. Conclusions: Enhanced depth imaging‑OCT can depict characteristic patterns that are suggestive of various choroidal tumors.

Expression and regulation of integrin receptors in human trophoblast cells: role of estradiol and cytokines.

Embryo implantation and placentation are dynamic cellular events that require not only synchrony between the maternal environment and the embryo, but also complex cell-cell communication amongst the implanting blastocyst and the receptive endometrium through integrins, a large family of proteins involved in the attachment, migration, invasion and control of cellular functions. Integrins display dynamic temporal and spatial patterns of expression by the trophoblast cells during early pregnancy in humans. However, the precise mechanism of embryo implantation and the modulation of the integrin receptors during blastocyst attachment and further implantation remain elusive in the humans. The present study elucidates the expression and hormonal modulation of fibronectin, vitronectin and laminin integrin receptors by estradiol and IL-1alpha in human trophoblast cells. Human first trimester trophoblast cells showed the induction of the classical estrogen receptor (ER)-alpha by its own ligand, estradiol. Treatment with either estradiol or IL-1alpha induced the expressions of alpha4, alpha5, alpha6 and alpha(v) integrin receptor subunits at both the mRNA and protein levels, while expression of beta1 remained unaltered. Furthermore, estradiol upregulated the expression of IL-1alpha, thereby suggesting the possibility that estrogen may either directly or via the proinflammatory cytokine induces the expression of the cell surface integrin receptors. The findings delineate the role of hormones and the cytokines in modulating the adhesiveness and attachment of the trophoblast cells. This may reflect the in vivo scenario where the implanting embryo is surrounded by a hormone-cytokine rich uterine microenvironment that may precisely regulate the expression of integrins and thereby facilitate implantation.

Extra-pituitary action of gonadotropin releasing hormone: possible application.

Chronic administration of a potent gonadotropin releasing hormone inhibits ovulation in women. The suppression of gonadal function during long term treatment with the GnRH analogues is ascribable to inhibition of gonadotropin secretion caused by the down regulatory action of the decapeptide at the pituitary level. Reduced progesterone production with premature onset of menstruation has been observed in women injected with the agonist during the midluteal phase. The decapeptide however, has no effect on in vitro human ovarian steroidogenesis. Specific receptors for GnRH have been located on rodent ovarian cells, but corpora lutea of rhesus monkey and human ovaries seem to lack these receptors. The luteolytic effect in women thus appears to be central in origin and not a direct effect on the corpus luteum. Recently, a superactive agonist of GnRH given around the peri-implantation period has been shown to terminate pregnancy in baboons. Monoclonal antibodies against GnRH administered during the same period in a fertile cycle also abrogated pregnancy in these animals. Using immuno-enzymatic techniques GnRH has been localized on the placenta. GnRH also exerts a stimulatory effect on hCG production by the placental villi maintained in culture. Addition of anti-luteinizing hormone releasing hormone antibodies blocks this effect completely. It seems that placenta is the only other tissue besides the pituitary where GnRH has probably a regulatory role in the human female.