Health risks from PAHs and potentially toxic elements in street dust of a coal mining area in India.

Polycyclic aromatic hydrocarbons (PAHs) and potentially toxic elements (PTEs) (Ba, Zn, Pb, Cu, Cr, Ni, As, Co) were determined in the road dusts of a coal mining area (Dhanbad, India) to assess their content and potential human health risks. Dust samples were collected from sign boards of the heavy traffic road connecting Dhanbad and Sindri. The total PAHs (∑PAHs, all values in mg/kg) content in the road dust samples varied from 3.98 to 13.1, with carcinogenic PAHs content of 14.8-34.4% of the ∑PAHs. Phenanthrene (2.72), fluorene (0.715) and pyrene (0.575) are the major PAHs. Principal component analysis revealed that these PAHs are probably originated from pyrogenic (coal combustion and traffic emission) and petrogenic (coal dust, tyre and road particles) sources. Among the PTEs, the mean content was higher for Ba (293 mg/kg) followed by Zn (224), Pb (128), Cu (52.6), Cr (45.2), Ni (22.0), As (17.5) and Co (8.11). The overall pollution load index varied from 0.43 to 1.0. Source analysis showed that PTEs in the road dust of the study site were derived from traffic emission (Zn, Fe, Mn, Co and Pb), coal dust (Cr, As and Ni) and soil (K, Mg, Ba, Sr and Ca). In general, the PTEs are lower, but the PAHs contents were elevated in the road dust samples. Although the exposure risks from PTEs are low, the risk to children (expressed as hazardous quotient) for As and Pb is near to the permissible limit of 1.0. Cancer risk from PAHs for adult (4.8 × 10-6) and child (5.3 × 10-6) has exceeded the acceptable limit of 10-6.

Clinical evaluation of immediate implants using different types of bone augmentation materials.

BACKGROUND: The immediate placement of implants into fresh extraction socket has proven to be a safe and predictable procedure. However, there is lack of scientific evidence regarding the healing pattern and osseointegration associated with immediate implants especially with different grafting materials. METHODS: A total of 30 patients male or female, with a mean age of 23.1 years ± 6.0 in the age group of 18-38 years, each having at least one tooth indicated for extraction (either maxillary or mandibular anterior teeth) were selected and randomly divided in to two groups. 30 Implants (Xive(®) friadent, Germany) were placed into fresh extraction sockets during this study. Two types of graft materials namely Dembone(®) (freeze-dried bone allograft) for group A and G-Bone(®) (modified hydroxyapatite) for group B were used. After implant placement all implants were evaluated clinically and radiographically at baseline, 3 months, 6 months, 9 months and 12 months. All clinical and radiographic parameters were subjected to statistical analysis. Intragroup comparisons were made with paired 't' test and intergroup comparisons with unpaired 't' test (P > 0.05 NS, ≤0.05 S, ≤0.01 HS). RESULT: During the 1-year interval, no implant was lost and the mean bone level at the implants was maintained or even improved. CONCLUSION: Immediate restoration of single tooth implants placed in fresh extraction sockets could be considered a valuable option to replace a missing tooth. The graft materials used in both groups have been found to be equally effective.

Intraocular pressure increases with fenoldopam, but not nitroprusside, in hypertensive humans.

Fenoldopam mesylate stimulates adenyl cyclase in porcine ocular trabecular meshwork and raises intraocular pressure in humans. To clarify whether this results from direct activation of the dopamine-1 receptor or indirectly from baroreflex sympathetic stimulation after blood pressure reduction, intraocular pressure was measured in 14 patients with accelerated/malignant hypertension, randomized between intravenous fenoldopam or sodium nitroprusside. Intraocular pressure was measured with a Perkins tonometer, before and at the twentieth minute of each dose increment. In seven patients with a mean blood pressure of 232/131 mm Hg treated with fenoldopam, intraocular pressure increased in a dose-dependent fashion, from 16 +/- 1 to 20 +/- 2 mm Hg (p less than 0.005). In contrast, seven patients with a mean blood pressure of 225/134 mm Hg treated with sodium nitroprusside exhibited no change in intraocular pressure (15 +/- 1 versus 14 +/- 1 mm Hg) despite similar blood pressure reduction. Increases in heart rate were not significantly different. Rates of urinary excretion of norepinephrine plus epinephrine increased significantly relative to baseline (p less than 0.05) but were not different between groups. These data suggest that the increase in intraocular pressure with fenoldopam results from specific activation of the dopamine-1 receptor and is not caused by baroreflex sympathetic stimulation. Because dopamine-1 receptors may modulate intraocular pressure, dopamine-1 receptor blockers might be useful therapy for glaucoma.

Evidence for the neuroectodermal origin of the human lacrimal gland.

Immunohistochemical staining with antineuronal-specific enolase antibodies showed a positive reaction product in the acini and in the nerves of human major and accessory lacrimal glands. The fibrous tissue interstitium, septae, capsule, and blood vessels reacted negatively. Our findings indicate that the acinar portion of the lacrimal gland, but not the fibrous tissue component, is derived from neuroectoderm. We propose that the acini of the human lacrimal glands develop, not as an ingrowth into the mesenchymal stroma from the surface ectoderm that forms the conjunctiva, but as an outgrowth from the embryonic neuroectoderm, and more specifically, from cells that have migrated from the neural crest.

Effect of arachidonic acid on normal and dystrophic retinal pigment epithelium in tissue culture.

With carmine particles used as markers, no significant difference was observed between the phagocytic activity of 1- to 3-week-old confluent monolayer cultures of normal and dystrophic retinal pigment epithelial (RPE) cells harvested from 1-day-old Royal College of Surgeons rats. The phagocytic activity of both normal and dystrophic RPE was markedly suppressed in a medium containing 1 mg/ml arachidonic acid (AA), and the cells rapidly assumed a rounded profile. With 100 micrograms/ml AA, the phagocytic activity of dystrophic RPE was differentially reduced compared with that of the normal sample (p greater than or equal to 0.001); this effect was subsequently accompanied by a gradual change in the shape of the cells. Lower concentrations of AA (5 microgram/ml and below) did not produce a significant effect in either group.

Analysis of glycoprotein deposits on disposable soft contact lenses.

By using gel electrophoresis, as well as Western blotting with specific antibodies or with the lectin concanavalin A, we characterized the types and amounts of proteins that are deposited on 58% ionic and 38% nonionic water-content disposable soft contact lenses (DSCLs) worn for 1 to 21 days by asymptomatic subjects with mild to moderate myopic refractive errors. The total amounts of protein eluted from the lenses ranged from 0.1 to 80 micrograms/lens. The amount of protein deposited on 58% water-content lenses was greater than that on 38% water-content DSCLs. We did not find a strict correlation between the amount of protein deposited and the duration of wear for either type of lens. The major polypeptide fractions detected had apparent molecular weights of 14, 17, 21, 30, and 60 kD. The fractions at 14 kD-bound antibodies specific for human lysozyme, and those at 17 kD corresponded to prealbumin. The 60 kD fraction included IgG heavy chains. The identity of the fractions at 21 kD and 30 kD is unknown. Because oligosaccharide side chains on the proteins attract microbes and facilitate their adherence, knowledge about the types of carbohydrate moieties in lens deposits can provide a rational approach to inhibiting or reversing microbial infection.

Modulation of pre-mRNA splicing and protein production of fibronectin by TGF-beta2 in porcine trabecular cells.

PURPOSE: To determine the effect of transforming growth factor (TGF)-beta2 on the pre-mRNA splicing pattern of fibronectin, as well as on the synthesis and secretion of this glycoprotein by porcine trabecular cells. METHODS: First-passage porcine trabecular cells were rendered quiescent and incubated in culture medium containing 15% newborn calf serum, in serum-free culture medium containing either activated TGF-beta2 (concentration range: 0.2-2.7 ng/ml) or activated TGF-beta1 (1 ng/ml), or in serum-free medium alone (untreated control samples). For investigation of alternative splicing, total RNA was extracted, and reverse transcription-polymerase chain reaction (RT-PCR) was performed with primer pairs located in exons flanking the exon (extra domain [ED]A, or EDB) that undergoes alternative splicing. The polymerase chain reaction (PCR) products were verified by Southern hybridization and quantified by using laser densitometry. The percentage of EDA-positive (+) isoforms was compared with that of the EDB+ isoforms among the groups. To study the effect of TGF-beta2 on the synthesis and secretion of fibronectin, total protein was extracted from both cultured cells and conditioned medium, Western blot analysis was performed using an anti-fibronectin antibody, and the products were quantified by laser densitometry. Immunocytochemical analysis was also performed on cultured trabecular cells to detect fibronectin. RESULTS: Fibronectin mRNA that was detected in untreated serum-starved control cells was EDA and EDB negative. Incubation of trabecular cells in medium containing 1 ng/ml TGF-beta2, 1 ng/ml TGF-beta1, or 15% newborn calf serum induced the expression of EDA+ and EDB+ mRNA to varying degrees. At concentrations of 0.2, 0.5, 1.5, and 2.7 ng/ml, TGF-beta2 increased the concentration of fibronectin by 2-, 3-, 3.8-, and 5-fold in the conditioned medium, and by 3-, 3.7-, 4-, and 4.3-fold in the cell extracts, respectively. The trabecular cells treated with TGF-beta2 exhibited strong immunoreaction for fibronectin, whereas the cells incubated in serum-free medium showed only minimal immunoreactivity. CONCLUSIONS: Our results demonstrate that TGF-beta2 and TGF-beta1 modified the alternative splicing pattern of fibronectin pre-mRNA and enhanced the synthesis and secretion of this extracellular matrix molecule by trabecular cells in a dose-dependent fashion. These findings indicate a mechanism whereby TGF-beta2, the concentration of which is elevated in aqueous humor of patients with primary open-angle glaucoma, contributes to the increased deposition of extracellular matrix molecules in the outflow pathway.

Identification and partial characterization of TGF-beta 1 receptors on trabecular cells.

By using two specific receptor assays, we identified and partially characterized receptors for transforming growth factor-beta 1 (TGF-beta 1) on porcine trabecular cells in vitro. Cultured trabecular cells were incubated with labeled TGF-beta 1 and analyzed by flow cytometry. Pretreatment with trypsin or preincubation with cold TGF-beta 1 or a neutralizing antibody to TGF-beta 1 inhibited the binding of labeled TGF-beta 1. 125I-TGF-beta 1 was cross-linked covalently to cell surface receptors on the trabecular cells. By SDS-PAGE and autoradiography, we identified three labeled macromolecular species of receptors, two of which had apparent molecular weights greater than 212 kDa and one of which had an apparent molecular weight of approximately 80-90 kDa under reducing conditions. The low and high molecular weight species probably represent type II and type III TGF-beta 1 receptors, respectively. At concentrations of 0.5 and 1 ng/ml, activated TGF-beta 1 caused retraction and a marked decrease in the rate of proliferation and in the motility of trabecular cells in vitro. Our findings implicate TGF-beta 1 in the modulation of the functional homeostasis of trabecular cells and suggest that the aqueous humor contains a level of TGF-beta 1 which, once activated, is sufficient to exert a biologic effect on the trabecular meshwork.

Transforming growth factor-beta 1 and -beta 2 positively regulate TGF-beta 1 mRNA expression in trabecular cells.

PURPOSE: To determine whether transforming growth factor (TGF)-beta 1 and -beta 2 and basic fibroblast growth factor (bFGF) induce the gene expression of TGF-beta 1 in the first-passage trabecular meshwork cells of the eye. METHODS: Trabecular meshwork cells were cultured from fresh porcine eyes and treated with 1 ng/ml of TGF-beta 1, TGF-beta 2, or bFGF for 1 hour. Cells maintained in serum-free medium were used as controls. Total cellular RNA was extracted, and the first-strand cDNA was synthesized. Multiplex polymerase chain reaction (PCR) and competitive PCR were performed on aliquots of the cDNAs by using either endogenous (glyceraldehyde-3-phosphate dehydrogenase [G3PDH]) or exogenous sequence (PCR mimic for TGF-beta 1) as internal standards, respectively. The obtained products were quantitated by laser densitometry, and statistical analysis was performed. RESULTS: The findings show that trabecular cells in vitro express the TGF-beta 1 messenger RNA constitutively. Both the techniques of multiplex PCR and competitive PCR demonstrated that the addition of either TGF-beta 1 or TGF-beta 2 at a concentration present in normal aqueous humor increased the mRNA levels of TGF-beta 1 by 2.82-to 3.07-fold over the controls, and these results were statistically significant (P < 0.01). Basic fibroblast growth factor did not have an effect on TGF-beta 1 expression (P < 0.05). CONCLUSIONS: Transforming growth factor-beta 1 activates its own gene expression in trabecular cells. Considering the multifunctional property of this cytokine, which includes increased deposition of extracellular matrix material and growth inhibition of trabecular cells, a change in its concentration within the eye would have a profound effect because of this autoinductive activity. Transforming growth factor-beta 2 treatment of trabecular cells also increased their expression of the TGF-beta 1 gene. The authors previously showed that the level of TGF-beta 2 in the aqueous humor of glaucomatous eyes is significantly higher than that of age-matched nonglaucomatous controls. The current finding suggests that this growth modulator may exert its effects directly on the trabecular cells or that it may act indirectly through upregulating the production of TGF-beta 1.

Extracellular release of tissue plasminogen activator is increased with the phagocytic activity of the retinal pigment epithelium.

Primary confluent cultures of retinal pigment epithelium (RPE) cells harvested from porcine eyes were challenged with latex spheres. The extracellular release of tissue plasminogen activator (t-PA) that was associated with phagocytosis of the beads by the RPE was measured by using enzyme-linked immunosorbent and chromogenic substrate assays. In the presence of serum and as compared to the controls, the phagocytosis of latex spheres produced a 5.5-fold increase in the amount of t-PA released into the ambient medium. Cell lysis was not a significant feature in either treated or control groups. Because the RPE in vivo is exposed to serum through the fenestrated choriocapillaris, and because phagocytosis by the RPE outer segments shed by the photoreceptors contributes to the maintenance of the functional integrity of the neural retina, we suggest that the release of t-PA associated with the phagocytic activity of RPE cells is an important physiologic event.

Changes in outflow facility in experimental hyphema.

To characterize the pathophysiology of hyphema clearance, we studied changes in the facility of outflow in experimental hyphema in freshly enucleated rabbit eyes. Hyphemas, with washed normal or sickled red cells (RBCs) (suspended in isotonic phosphate buffer to obtain a hematocrit value comparable to that of whole blood) and occupying 50% to 100% of the anterior chamber volume, caused a marked cell "crowding" in the chamber angle and an increase in the outflow resistance; the facility stabilized at a value 60% lower than the control (p = < 0.001). No significant change in outflow facility was observed in hyphemas of either RBC type occupying 25% of the anterior chamber volume (p = N.S.). Whole blood hyphema occupying 50% of the anterior chamber volume reduced the facility of outflow by 80% of the control mock aqueous value (p = < 0.001); a comparison with 50% hyphema produced by washed RBCs indicated a significant contribution by the plasma (fibrin) component (p = 0.0025) in increasing the resistance to outflow.

Trabecular cells of the eye express messenger RNA for transforming growth factor-beta 1 and secrete this cytokine.

PURPOSE: To determine whether trabecular tissue in vivo and cultured trabecular cells have the messenger RNA transcript for transforming growth factor-beta 1 (TGF-beta 1), and to examine whether these cells synthesize and secrete TGF-beta 1 in vitro. METHODS: Total RNA was isolated from the trabecular meshwork, iris, and ciliary body freshly excised from porcine eyes as well as from cultured trabecular cells, and the reverse transcriptase-polymerase chain reaction and Southern hybridization were used for detection of TGF-beta 1 messenger RNA. The amount of TGF-beta 1 secreted by trabecular cells in culture was determined by radioimmunoassay. RESULTS: Excised whole trabecular tissue, iris, and ciliary body, as well as cultured trabecular cells expressed messenger RNA transcripts for TGF-beta 1. On the ethidium bromide-stained agarose gel, two PCR-amplified products (161 and 400 base pairs) were found in the total RNA isolated from cultured trabecular cells. The oligonucleotide probe specific for TGF-beta 1 detected only one band with the expected length of 161 base pairs. The secretion of TGF-beta 1 into conditioned medium was at the level of 16.7-20 pg/ml per 2 million trabecular cells during a 24-hr period. CONCLUSIONS: These investigations show that the trabecular meshwork, iris, and ciliary body in vivo express the messenger RNA transcript for TGF-beta 1, and that trabecular cells in vitro synthesize and secrete this cytokine. The TGF-beta 1 present in normal aqueous humor may be derived locally, at least in part, from the cells of the trabecular meshwork, iris, and ciliary body. Abnormal synthesis, secretion, activation, and clearance of TGF-beta 1 may contribute to the pathogenesis of many ocular disorders, including primary open-angle glaucoma.

Species variations in distribution of S100 in retina. Demonstration with a monoclonal antibody and a polyclonal antiserum.

The S100 protein has been found consistently in glial cells both in the central nervous system (CNS) and peripheral nervous system (PNS). However, in the retina we find substantial species variation in the distribution of this protein. Immunohistochemically, in the human retina we do not find any S100. In the rabbit retina it is present both in Müller cells and in astrocytes and in the chicken retina it is in neurons. This demonstrates how misleading it can be to use the distribution of a protein in one species to generalize about the distribution of the same protein in other species. It is also clear that even though immunohistochemical staining for the S100 protein could be used to study pathologic conditions that involve Müller cells in guinea pigs, hamster, rat, and rabbit retina it is going to be of limited value in investigations of the same conditions in the human eye.

Identification and quantification of transferrin receptors on trabecular cells.

The authors identified and quantified the receptor for transferrin on trabecular meshwork (TM) cells cultured from porcine eyes by using two receptor assays. Flow-cytometric analysis of TM cells that were incubated with a monoclonal antibody to the transferrin receptor revealed such receptors, which decreased in number as the cells passed from the pre- to the post-confluent phase. Quantitative characterization by radioligand binding of 125I-transferrin to trabecular cells followed by Scatchard analysis showed that pre-confluent cultures expressed 23,839 +/- 6746 high-affinity receptors/cell and post-confluent cultures expressed 5104 +/- 3639 receptors/cell. The expression of the receptor for transferrin reflects the index of mitotic activity and can be correlated with the proliferative state of the trabecular cells. Further characterization of the receptors for transferrin in the TM may open up the possibility of a pharmacologic approach that enhances the TM cell population, which is known to decrease with age and in glaucomatous states of the eye.

Quantitative and qualitative analyses of transferrin in aqueous humor from patients with primary and secondary glaucomas.

By using a highly sensitive and specific radioimmunoassay and the slot-blot technique, transferrin was quantified in fresh samples of aqueous humor from patients with primary open-angle glaucoma (POAG, n = 36) or secondary glaucoma (SG, n = 18). The levels were compared with those in aqueous humor obtained from age-matched patients without glaucoma (n = 33) and in primary and secondary aqueous humor from normal dogs (n = 10) in which breakdown of the blood-aqueous barrier was induced experimentally. The concentration of transferrin in the aqueous humor of human control subjects ranged from 0.3-3.4 mg/dl (mean +/- standard deviation, 1.36 +/- 0.66 mg/dl); in POAG samples, from 0.34 to greater than 10 mg/dl (2.07 +/- 1.90 mg/dl); and in SG samples, from 0.29 to greater than 10 mg/dl (2.79 +/- 2.24 mg/dl). The level of transferrin in secondary aqueous humor samples obtained from dogs was as much as ninefold greater than that in primary aqueous humor. The protein concentration in the human aqueous humor samples was 11.87 +/- 4.47 mg/dl for control subjects, 62.11 +/- 56.74 mg/dl for patients with POAG, and 124.53 +/- 152.67 mg/dl for those with SG. In dogs, the protein levels were 7.97 +/- 3.12 mg/dl for primary aqueous humor and 191.9 +/- 149.8 mg/dl for secondary aqueous humor. A significant correlation (r = 0.744, P less than 0.01) was found between total protein and transferrin contents in the samples of aqueous humor from patients with glaucoma but not in the samples from age-matched control subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Synthesis of a thrombospondin-like cytoadhesion molecule by cells of the trabecular meshwork.

Thrombospondin is a large extracellular-matrix protein that is released by smooth muscle cells and platelets and is distributed widely in mammalian brain. By using western blotting with a monoclonal antibody against the calcium-binding domain of thrombospondin, the authors detected a 180-kD glycated polypeptide in the trabecular meshwork tissue of normal human and porcine eyes. The epitope-bearing polypeptide was soluble in sodium dodecylsulfate/urea (SDS/urea), and apparently it was stabilized in part by disulfide bonding to the Triton X-100 and SDS/urea-insoluble pellet of this tissue. Treatment of the insoluble matrix with beta-mercaptoethanol led to an enriched extraction of the approximately 160-kD form of thrombospondin. On immunohistochemical study, the thrombospondin antibody also reacted positively with the extracellular matrix and intracellular structures of trabecular cells in primary monolayer culture. This suggested that the presence of thrombospondin in the trabecular meshwork was probably due to local synthesis. These findings are relevant to the establishment of a model in vitro for assessment of adhesion of trabecular cells. Because thrombospondin is a cell-substrate adhesion molecule, its role in the loss of cellularity that occurs in the trabecular meshwork of the aging eye and in eyes with primary open-angle glaucoma is worthy of further investigation.

Effects of dopamine receptor activation on the level of cyclic AMP in the trabecular meshwork.

We examined the effects of dopamine and of a selective DA1 agonist, fenoldopam, on the levels of cyclic AMP in the trabecular meshwork, freshly excised from porcine and canine eyes. As measured by radioimmunoassay, fenoldopam at a concentration of 10(-5) M caused a 4-fold increase in the cyclic AMP content, from a basal level of 24.4 +/- 1.9 to 101.8 +/- 6.3 pmol/mg protein, of the trabecular meshwork samples from porcine eyes. In tissue samples from canine eyes, fenoldopam at a concentration of 10(-4) M increased the endogenous cyclic AMP level from a basal value of 26.0 +/- 4.6 to 64.2 +/- 5.7 pmol/mg protein. Dopamine, although less potent, produced a similar response. Preincubation with a DA1 receptor antagonist, SCH 23390, inhibited the increase in cyclic AMP levels by 90%. Such inhibition did not occur with the alpha- and beta-receptor antagonists phenoxybenzamine and propranolol, respectively. This investigation demonstrates that adenylate cyclase-coupled DA1 receptors are present in porcine and canine trabecular meshwork tissue.

Trabecular cells express receptors that bind TGF-beta 1 and TGF-beta 2: a qualitative and quantitative characterization.

PURPOSE: To quantitate the receptors for transforming growth factor (TGF)-beta 1 on trabecular cells in culture and to determine the relative affinities of TGF-beta 1 and TGF-beta 2 for these receptors. METHODS: We quantitated the receptors for TGF-beta 1 by Scatchard analysis of radioligand binding of 125I-TGF-beta 1 to cultured porcine trabecular cells. We established the relative affinities of TGF-beta 1 and TGF-beta 2 for the receptors by competitive binding of 125I-TGF-beta 1 with increasing concentrations of the unlabeled TGF-beta 1 or TGF-beta 2. We also investigated the binding of 125I-TGF-beta 1 after pre-treatment of trabecular cells with heparinase. RESULTS: Trabecular cells expressed approximately 4,000 high-affinity receptors per cell for TGF-beta 1, with a dissociation constant (Kd) of 15.8 +/- 7.6 pmol/l. By varying the concentrations of the unlabeled growth factors, we determined that the relative affinities of TGF-beta 1 and TGF-beta 2 for the receptors were 16 pmol/l and 50 pmol/l, respectively. Heparinase treatment of the trabecular cells did not change the binding affinity of the receptor for 125I-TGF-beta 1. CONCLUSIONS: Our findings show that trabecular cells express heparinase-insensitive TGF-beta receptors that have an approximately threefold greater affinity for TGF-beta 1 than for TGF-beta 2. Based on the present investigation, together with our previous data on the molecular weights of the binding sites, we conclude that trabecular cells do possess types II and III receptors but not type I receptors.

Tissue plasminogen activator in the trabecular endothelium.

By quantitative analysis of tissue plasminogen activator (TPA) in the trabecular endothelium, corneal endothelium, and iris in the eyes of monkeys and dogs, we found significant levels of TPA activity. In a [125I]fibrin-coated well assay, the levels for the dog and monkey were, respectively: trabecular endothelium, 0.2 and 0.5; corneal endothelium, 0.8 and 0.5 IU per mg protein. The iris tissue showed high TPA activity, but its protein content could not be measured with the techniques employed. Activity in the aqueous humor was not detectable. By the ELISA technique, the values (in ng TPA/mg tissue protein) for the dog and monkey were, respectively: trabecular endothelium, 0.16 and 0.44; corneal endothelium, 0.48 and 0.92. Again, iris tissue showed high TPA activity, whereas the aqueous humor showed low activity (0.86 ng/ml). The data obtained with the two methods showed a reasonable consistency, although a direct comparison was not possible because two separate standards were used. The presence of TPA in the trabecular endothelium, corneal endothelium, and iris may be important in modulating the resistance to aqueous outflow under normal conditions as well as those of hyphema.

Multiple dosing of prostaglandin F2 alpha or epinephrine on cynomolgus monkey eyes. III. Histopathology.

Prostaglandins (PGs), or their derivatives, are potent ocular hypotensive agents which may prove useful in glaucoma therapy. PGF2 alpha (250 micrograms in 50 microliter saline) or epinephrine 2% solution (50 microliter) was topically applied twice daily for 2 weeks to one eye of six cynomolgus monkeys for each agent. Contralateral control eyes received their respective vehicles. By light microscopy, there was no evidence of inflammation, corneal changes, retinal pathology (including cystoid macular edema), or other adverse effects. Likewise, by electron microscopy of the peripheral cornea, anterior chamber angle, iris base and ciliary body, no differences were noted between treated and control eyes. Therefore, multiple dosing with PGF2 alpha in subhuman primate eyes did not result in notable histopathological changes that would contraindicate a clinical trial in glaucoma patients.