Ratio of size of recipient and donor areas in treatment of vitiligo by autologous cultured melanocyte transplantation

BACKGROUND

Autologous melanocytes can be expanded in vitro, allowing the treatment of large lesions of vitiligo in one session. Theoretically, this procedure could provide a higher donor/recipient size ratio (DR ratio) compared with that in noncultured cell transplantation (with a DR ratio < 1 : 10). However, the exact DR ratio obtained from this procedure has not been reported.

OBJECTIVES

To study whether transplantation of cultured pure melanocytes at a high DR ratio is as efficient as that at a low DR ratio.

METHODS

One hundred and two patients with vitiligo were treated by transplantation of cultured pure melanocytes and were divided into two groups: a low DR ratio group, including patients with DR ratio ≤ 1 : 10 (mean 1 : 8, 35 cases) and a high DR ratio group with DR ratio > 1 : 10 (mean 1 : 27, 67 cases). The extent of repigmentation between these two groups was compared.

RESULTS

There was no significant difference in repigmentation between the low DR ratio group (mean ± SD 77·4 ± 22·5%) and the high DR ratio group (77·6 ± 24·8%). Multiple regression analysis showed that even after adjustment for age, sex, type of vitiligo and transplanted cell density, there was no significant correlation between the extent of repigmentation and the DR ratio, indicating that patients treated with high DR ratio obtained a satisfactory result and showed no difference from the low DR ratio group.

CONCLUSIONS

Various surgical procedures for the treatment of vitiligo which involve melanocyte transplantation or skin grafts have different inherent DR ratios. Transplantation of cultured pure melanocytes is an expensive and complicated procedure; however, it provides the highest DR ratio (> 1 : 10 and up to 1 : 60). Surgeons can select one of these methods for the treatment of vitiligo based on their experience and skill, on the size of lesions, and the availability of laboratory support.

Treatment of vitiligo in children and adolescents by autologous cultured pure melanocytes transplantation with comparison of efficacy to results in adults

BACKGROUND

Transplantation of autologous cultured pure melanocytes is a well-established procedure for the treatment of refractory and stabilized vitiligo. However, there was no report specifically comparing the efficacy with the regard to defined age groups (children-adolescence-adult).

OBJECTIVE

  We analysed the efficacy of this procedure in the treatment of vitiligo in children and adolescents and compare it with the results in adults treated during the same period and using identical procedures.

METHODS

Melanocytes were isolated from the roof of suction blister, cultured and expanded with Hu16 medium in vitro, and transplanted to laser-denuded receipt area. A total of 12 children (8-12 years), 20 adolescents (13-17 years) and 70 adults with vitiligo were treated using this procedure.

RESULTS

The patients obtained satisfactory results (repigmentation of 50% or more) results in children, adolescents and adults were 83.3%, 95.0% and 84.0% respectively. The mean extent of repigmentation in children, adolescents and adults was 80.7%, 78.9% and 76.6% respectively. There was no statistical difference in repigmentation among these three groups. After adjusting for all factors (gender, type of vitiligo, period of stability, location of the lesion or transplanted cell density) individually or totally using multiple regression analysis, age still did not correlate to the extent of repigmentation.

CONCLUSIONS

The satisfactory results obtained in the treatment of vitiligo in children and adolescents by transplantation of cultured autologous pure melanocytes are comparable with the results in adults. Therefore, this procedure can be considered in refractory and stable vitiligo in children and adolescents, especially in patients with large vitiliginous lesions.

Cleft lip with or without cleft palate and dermatoglyphic asymmetry: evaluation of a Chinese population

OBJECTIVE

To determine if Chinese individuals with non syndromic cleft lip with or without cleft palate (CL/P) display more dermatoglyphic asymmetry than unaffected relatives or controls.

DESIGN

Case-control study with two control groups (genetically related and unrelated).

SETTING AND SAMPLE POPULATION

A total of 500 CL/P probands from Shanghai, China, 421 unaffected relatives, and 66 controls of Chinese heritage.

METHODS

Finger and palm prints were collected, and pattern frequencies, total ridge counts (TRC), and atd angles were calculated. Asymmetry scores between right and left hands were defined for each of the three dermatoglyphic measures. Probands' asymmetry scores were compared statistically with the scores of unaffected relatives and controls.

RESULTS

In general, the probands' asymmetry scores for TRC and atd angle did not differ significantly from the scores of either unaffected relatives or controls. However, probands with a positive family history of clefting showed significantly more asymmetry in their pattern types than either probands without a family history, unaffected relatives or controls.

CONCLUSION

These results suggest that a unique genetic mechanism of developmental instability may obtain in CL/P individuals with a positive family history of clefting.

The effect of combined 5-fluorouracil and dexamethasone on cultured human retinal pigment epithelial cells

This study was designed to investigate the inhibitory effect of 5-fluorouracil (5-FU) and dexamethasone (DEX) on the proliferation of human retinal pigment epithelial (RPE) cells in vitro. The human RPE cells (R-50 cell line) were cultured and exposed to various concentrations of combined 5-FU (0, 250, 500, 1000, 2000 ng/ml) and DEX (0, 1, 10, 100, 200 micrograms/ml). The cells were incubated for 96 hr and the medium was changed every 48 hr to replenish the drug action. Cell viability was assessed using cell counting and trypan blue exclusion method. Tetrazolium salt, which can be metabolized by mitochondrial dehydrogenase to form a formazan dye, was used to assay cell proliferation. Treatment with 5-FU alone inhibited cell proliferation in a dose-dependent manner. The concentration of 5-FU that inhibited growth by 50% (IC50) was found to be 704.12 ng/ml. There was a bimodal effect of DEX on RPE cells--stimulation at low concentrations (1, 10 micrograms/ml) and inhibition at high concentrations (100, 200 micrograms/ml). When the two drugs were combined, there was additive inhibition in the concentration of 200 micrograms/ml of DEX. These results indicate that a combination of 5-FU and DEX is no more effective in the inhibition of human RPE cells, except in combination with high concentrations of DEX (> or = 200 micrograms/ml).

Patterns of retinal ganglion cell survival after brain-derived neurotrophic factor administration in hypertensive eyes of rats

We investigated the effect of brain-derived neurotrophic factor (BDNF) on retinal ganglion cell (RGC) survival after intraocular pressure (IOP) elevation at various time intervals. In adult Wistar rats, RGCs were labeled with 5% Fluorogold. Animals with 1.8-2.5-fold increase in IOP after cauterization of three episcleral vessels, were divided into three BDNF groups and three vehicle control groups, each receiving one, two or three injections. The RGC survival percentage on RGCs of the first, second and third injections were 93.9% (n = 7), 91.3% (n = 7), 82.7% (n = 5), respectively in BDNF groups; 91.6% (n = 6), 84.1% (n = 6) and 73.5% (n = 5), respectively in vehicle controls. The second and third injections of BDNF showed statistically significant survival effects. These findings demonstrated that BDNF has partial neuroprotection on RGCs in whole retina and enhances RGC survival in moderately chronic hypertensive eyes.

A functional study on prostanoid receptors involved in cultured human iridal melanocyte stimulation

The effects of various prostanoids on the growth, melanogenesis and dendrification of cultured iridal melanocytes were studied. Iridal melanocytes were isolated and cultured with medium supplemented with cAMP elevating agents and basic fibroblast growth factor (bFGF) (complete medium). The iridal melanocytes were plated into multiple well plates and cultured with complete medium or various deleted media with or without various prostanoids at different concentrations. After 6 days, the numbers of cells and dendrites were counted and melanin content was measured and compared with controls. Prostaglandin E(2), an EP(2)receptor agonist (AH 13205) and AGN 192093 (thromboxane mimetic) stimulated growth, melanogenesis and dendrification of cultured iridal melanocytes in cAMP-deleted medium. A mixed EP(1)and EP(3)receptor agonist (sulprostone), a EP(4)receptor agonist (ONO-AE1-329), IP receptor agonists (cicaprost or iloprost) and a TP receptor agonist (U-46619) showed no effect. Prostaglandin D(2)showed stimulating effects. However, these stimulating effects could not be blocked by the addition of a DP receptor antagonist (BW A868C). Furthermore, a DP receptor agonist (BW 245C) showed no effects, indicating that the effect of prostaglandin D(2)may involve receptors other than the DP receptor subtype. The present study indicates that: (1) among various EP receptor agonists, only an EP(2)receptor agonist has stimulating effects on iridal melanocytes; (2) DP, IP and TP receptor agonists do not have stimulating effects; and (3) the mechanisms of action of prostaglandin D(2)and AGN 192093 need further study.

Hepatocyte growth factor is increased in the aqueous humor of glaucomatous eyes

PURPOSE

To assess the concentrations of hepatocyte growth factor (HGF) in the aqueous humor of eyes with glaucoma compared with control eyes with cataract only.

METHODS

Concentrations of HGF were measured in aqueous humor aspirates taken during anterior segment surgery from 84 patients, of whom 72 had glaucoma (38 cases of primary open-angle glaucoma, 17 angle-closure glaucoma, and 17 exfoliative glaucoma) and 12 had cataract only, using a sandwich enzyme-linked immunosorbent assay kit.

RESULTS

Hepatocyte growth factor was detected in all samples. The concentration in eyes with cataract only was 563.3 +/- 178.8 pg/mL (mean +/- standard deviation), which was significantly lower than that in eyes with glaucoma (967.1 +/- 514.7 pg/mL, P < 0.01). Eyes with exfoliative glaucoma had significantly higher HGF concentrations (1,425.5 +/- 586.7 pg/mL) than did eyes with primary open-angle glaucoma (855.0 +/- 341.5 pg/mL) and angle-closure glaucoma (759.4 +/- 511.4 pg/mL) (P < 0.01). There was no effect of age, sex, or history of medical, laser, or surgical treatment on the aqueous humor HGF concentration (P > 0.05). Aqueous humor and plasma HGF concentrations were measured and compared in 28 patients. The aqueous humor HGF concentration (908 +/- 586.2 pg/mL) was significantly higher (P < 0.01) than the plasma concentration (521.3 +/- 183.1 pg/mL). No significant correlation could be found between aqueous humor and plasma HGF concentrations.

CONCLUSIONS

The relatively high concentration of HGF in human aqueous humor suggests that HGF may play an important role in ocular physiology and disease. The higher concentration in patients with glaucoma may indicate a response to injury.

Regulation of growth and melanogenesis of uveal melanocytes

We have developed methods for the isolation, cultivation, and investigation of human uveal melanocytes (UM). Uveal melanocytes grow well and produce melanin in vitro in the presence of basic fibroblast growth factor (bFGF), cyclic adenosine monophosphate-elevating agents, and serum. Cultured UM respond to various factors. Certain growth factors (bFGF and hepatocyte growth factor, etc.), endothelin, adrenergic beta2-receptor agonists, and some prostaglandins (EP2-receptor agonists and certain TP-receptor agonists) stimulate, while transforming growth factor-beta2, interleukin-6, and cholinergic agonists inhibit melanogenesis and/or growth of UM in vitro. Alpha-melanocyte-stimulating hormone, adrenocorticotropic hormone, various sex hormones, and prostaglandin F2alpha showed no effect on the growth and melanogenesis of cultured UM. The stability of UM in vivo may be controlled by these factors. Disturbance of this balance may lead to certain rare pathologic pigmentary changes of the iris. UM are relatively stable in vivo; they usually do not respond (proliferate or show dynamic changes in melanogenesis) to various environmental factors. The differences of the in vivo behavior between uveal and epidermal melanocytes may be determined by both cellular factors and environmental factors.

Characterization of a novel cationic drug transporter in human retinal pigment epithelial cells

Retinal pigment epithelial (RPE) cells transport a variety of solutes, but the capacity of human RPE cells to transport drugs and xenobiotics is not well understood. As an initial step to address this issue, we have examined human RPE transport of verapamil. Transport of [3H]verapamil was measured in two human RPE cell lines (RPE/Hu and ARPE-19) grown to confluence on 12-well culture plates. Verapamil uptake by RPE/Hu cells was highly concentrative, reaching cell-to-medium ratios as high as 42 by 1 h. Uptake was saturable, with an apparent K(m) of 7.2 microM. Verapamil uptake decreased in the presence of metabolic inhibitors, low temperature, and organic cations, including quinidine, pyrilamine, quinacrine, and diphenhydramine. However, other organic cations, including tetraethylammonium and cimetidine failed to inhibit. Verapamil uptake was also inhibited by the cationic antiglaucoma drugs diltiazem, timolol, and propranolol. Verapamil uptake was insensitive to changes in membrane potential. However, transport was markedly altered by changes in pH. Decreasing external pH inhibited uptake, whereas efflux was stimulated. Intracellular acidification via NH4Cl prepulse also stimulated uptake. Identical findings were obtained using the commercially available cell line ARPE-19. In view of its unique specificity, the RPE cell verapamil transporter described above is a novel, heretofore undescribed, organic cation transporter, distinct from the known members of the OCT family of organic cation transporters.

Relationship between outcome of proliferative vitreoretinopathy and results of tissue culture of excised preretinal membranes

The purpose of this study was to explore the relationship between clinical post-surgery outcome of proliferative vitreoretinopathy (PVR) and the laboratory results of tissue culture, the specimens of which were excised of pre- or subretinal membranes from PVR patients. Surgically excised membranes from 25 PVR patients were microdissected into small pieces and plated into culture dishes with F12 medium supplemented with 30% fetal bovine serum. After primary culture became confluent, cells were passaged in subculture with F12 medium (10% fetal bovine serum). PVR patients were followed-up after surgery for an average of 21 months. The clinical outcome was compared, according to the growth pattern of the cells derived from the explanted membranes. In 25 PVR patients, 16 cases showed cell migration in the membrane, and cells grew rapidly to confluence in the primary culture in 7 cases. All active growing cells were identified as retinal pigment epithelial (RPE) cells by immunocytochemistry. In 7 cases with active cell growth, all had recurrent retinal detachment. In 18 cases without active cell growth, only 4 cases had the same outcomes. Statistical study showed that the difference between these two groups was significant (P < 0.01). These results indicate that the growth capacity of cultured RPE derived from excised membranes of PVR patients strongly influenced the prognosis for surgery.

Latanoprost-induced increase of tyrosinase transcription in iridial melanocytes

PURPOSE

Latanoprost, the active principle of Xalatan eye drops, has been shown to cause increased iridial pigmentation as a side-effect in some patients. The purpose of the present study was to investigate whether latanoprost affects tyrosinase, the rate limiting enzyme in melanogenesis, at the gene transcription level in the iridial melanocytes.

METHODS

Four cynomolgus monkeys were treated unilaterally with 3 or 11 microg latanoprost once daily for 10 days. The contralateral eye received the vehicle only. Tyrosinase mRNA was visualized by in situ hybridization using radio-labelled riboprobes. The transcription of tyrosinase was also studied in vitro using cultivated human iridial melanocytes. Tyrosinase RNA was quantified by Northern blotting.

RESULTS

In the monkeys transcription of tyrosinase was found to be increased in iridial melanocytes of the treated eyes compared to the control eyes. Increased transcription of tyrosinase was in addition found in the iridial pigment epithelium and in melanocytes of the anterior choroid. Latanoprost was also found to increase the transcription of tyrosinase in melanocytes isolated from at least one human eye.

CONCLUSIONS

Although the tyrosinase enzyme has to undergo complex post-translational modification to become biologically active, which we have not studied, it appears that latanoprost treatment may increase the transcription of the tyrosinase gene in some individuals, consistent with increased melanogenesis in the iridial melanocytes leading to darker eye colour.

Photophysical studies on melatonin and its receptor agonists

Previous work has demonstrated that melatonin inhibits the growth of both dermal and uveal melanoma cells. Recent clinical trials have found that melatonin is an efficacious treatment for metastatic dermal melanoma. The goal of this study was to provide further insight into the oncostatic mechanism(s) of melatonin. The inhibition of the growth of uveal melanoma cells is dose-dependent (0.1-10 nM) within the range of endogenous melatonin concentrations (2 nM) found in the human aqueous humor. We know that this inhibition of growth is receptor-mediated, at least in part, because uveal melanoma cell growth was also blocked by the agonists of melatonin receptors. There are two known membrane receptors for melatonin (Mel(1a) and Mel(1b)) and one known nuclear receptor (Mel2). To determine if singlet oxygen production and/or quenching contributed to the growth inhibition of melatonin, we examined the photophysical properties of melatonin and its agonists. Using flash photolysis, we determined that melatonin and its membrane receptor agonist 6-chloromelatonin (Mel(1a-b), Lilly, Indianapolis, IN) produced very little singlet oxygen (psidelta = 0.073 and psidelta = 0.01, respectively). There was no detectable singlet oxygen phosphorescence at 1,270 nm for the nuclear receptor agonist CG-52608 (Mel2, Novartis, Basel, Switzerland). In contrast, the agonist of the Mel(1b) receptor, S-20098 (Servier, Paris, France), produced singlet oxygen with a quantum efficiency of psidelta = 0.34. Singlet oxygen was quenched by melatonin and 6-chloromelatonin at approximately the same rate (6.1 x 10(7) M(-1)s(-1) and 6.0 x 10(7) M(-1)s(-1) in CD3OD), while the rate of quenching for the nuclear receptor agonist CG-52608 and membrane receptor agonist S-20098 was less (2.2 x 10(7) M(-1)s(-1) and 1.5 x 10(7) M(-1) s(-1), respectively). It appears that the production of singlet oxygen by melatonin would not be sufficient to directly block the proliferation of melanoma cells, but may activate gene products that could contribute to the oncostatic effect.

Influence of autonomic neurotransmitters on human uveal melanocytes in vitro

The influence of autonomic neurotransmitters on the growth and melanogenesis of cultured uveal melanocytes was studied. Uveal melanocytes were cultured with medium supplemented with cAMP elevating agents and basic fibroblast growth factor (complete medium). The cells were plated into multiple well plates, and various concentrations of adrenergic and cholinergic agents were added to the media (complete medium or various deleted media). After 6 days, the cells were detached for cell counting and melanin measurement and compared to controls. Epinephrine, isoproterenol, salbutamol and metaproterenol (adrenergic agonists that can activate beta(2)-adrenoceptors) substantially stimulated growth and melanogenesis of cultured uveal melanocytes in cAMP-deleted medium. Methoxamine, clonidine, prenalterol and D-7114 (adrenergic agonists that do not activate beta(2)-adrenoceptors) showed no effect under similar experimental conditions. Muscarine (a cholinergic agonist) inhibited the growth and melanogenesis of uveal melanocytes in complete medium. It indicates that adrenergic agents (beta(2)-adrenoceptor agonists) stimulate growth and melanogenesis in uveal melanocytes, while cholinergic agonist has an inhibitory effect. This effect appears to involve the cAMP second messenger system. These studies suggest that homeostasis of the uveal melanocytes may be maintained, in part, by regulating the autonomic nervous system in vivo.

The combined effect of brain-derived neurotrophic factor and a free radical scavenger in experimental glaucoma

PURPOSE. Brain-derived neurotrophic factor (BDNF) had a limited effect on the survival of retinal ganglion cells (RGCs) in rats' eyes with elevated intraocular pressure (IOP). The combined treatment of BDNF and a nonspecific free radical scavenger N-tert-butyl-(2-sulfophenyal)-nitrone (S-PBN) was investigated on the RGCs in hypertensive eyes of rats.

METHODS

Adult Wistar rats were separated into five groups: BDNF (0.5 microg) + S-PBN; BDNF (1. 0 microg) + S-PBN; BDNF (1.0 microg); S-PBN; and phosphate-buffered saline. Right eyes served as normal controls (n = 10). RGCs were labeled with 5% Fluoro Gold; injected into the superior colliculus. Three days after intratectal injection, the episcleral veins of the left eyes were cauterized. Intravitreal injection of BDNF was performed on days 5, 13, 21, and 29 after IOP elevation. S-PBN was injected intraperitoneally (100 mg/kg body wt) every 12 hours starting 30 minutes after cauterization.

RESULTS

The survival of RGCs using BDNF treatment alone in moderately hypertensive eyes and systemic administration of S-PBN alone did not significantly rescue the RGCs. However, the combination of BDNF and S-PBN increased the survival of RGCs to 90.1%.

CONCLUSIONS

Trophic factors and antioxidants have synergistic effects on rescuing RGCs from death in eyes with elevated IOP. Further studies of different combined treatment therapies may provide avenues to save RGCs from death in eyes with elevated IOP.

Transplant of cultured autologous pure melanocytes after laser-abrasion for the treatment of segmental vitiligo

Segmental vitiligo is a special type of vitiligo with unilateral distribution of lesions and has a stable course. Clinically, many patients with segmental vitiligo have unsatisfactory responses to topical corticosteroid or UV phototherapy. We have developed a technique for the isolation of melanocytes from a small specimen of normally pigmented skin obtained via a suction blister. The melanocytes can be proliferated in culture and then replanted onto laser-abrased vitiliginous areas. We used this procedure to treat 25 patients with segmental vitiligo that were refractory to medical therapy. The repigmented portion of the total treated area amounted to 95-100% in 21 patients and 65 to 94% in 4 patients. The response rate to treatment was 100% in this study. No scarring or other side-effects developed. The results of this study demonstrate that this method is a valuable tool for the treatment of patients with segmental vitiligo.

Descriptive epidemiology of nonsyndromic cleft lip with or without cleft palate in Shanghai, China, from 1980 to 1989

OBJECTIVE

The purpose of this study was to characterize nonsyndromic cleft lip with or without cleft palate (CL+/- CP) in an Asian population.

DESIGN

Birth prevalence was assessed in a large birth series in Shanghai, China. A 1:3 sex-age-hospital matched case-control design was used to assess the effects of parental ages and pregnancy history on risk of CL+/- CP.

PARTICIPANTS

Records of live births from 1980 to 1989 in 22 hospitals in Shanghai, China, were reviewed, comprising 541,504 consecutive births, which is by far the largest such Chinese sample ever investigated. The case-control study included 528 (308 male, 220 female) nonsyndromic CL+/- CP cases and 1,563 (912 male, 651 female) controls.

RESULTS

From 1980 to 1989, the overall birth prevalence was 1.2 per 1,000 live births with statistically significant seasonal variation (more CL+/- CP births in January to July). The overall male:female ratio was 1.40:1. For males, statistically significant associations were identified with maternal age for the most severe clefts (bilateral overall, and also bilateral CL+CP subgroup). For females, statistically significant association was shown for pregnancy age with birth order (overall and in most subgroups).

CONCLUSIONS

The birth prevalence of CL+/- CP in this Asian population was similar to published Caucasian rates. The observed seasonal variation would be consistent with possible environmental factors. Significant associations with maternal age, pregnancy age, and birth order warrant additional study of pregnancy history in Asian CL+/- CP.

Melatonin receptors in human uveal melanocytes and melanoma cells

Previous work has demonstrated that melatonin inhibits growth of cultured human uveal melanoma cells. The goal of this study was to determine the expression of mRNA encoding the melatonin receptor subtypes and the effect of specific melatonin receptor agonists on cell growth of uveal melanoma cells and melanocytes. RNA expression of the human melatonin Mel1a and Mel1b receptor subtypes was determined by reverse transcription-polymerase chain reaction (RT-PCR) amplification of RNA isolated from two melanoma cell lines and from one cell line of normal melanocytes. PCR-amplified cDNA encoding the Mel1b melatonin receptor subtype, but not the Mel1a subtype, was detected in reverse-transcribed RNA obtained from both normal uveal melanocytes and melanoma cell lines. Uveal melanoma cells and melanocytes were cultured for 24 hr, then melatonin or one of its membrane receptor agonists, 6-chloromelatonin (Mel1a-1b) or S-20098 (Mel1b) or its putative nuclear agonist, CGP-52608 (Mel2), was added to the medium. After 5 days, the cells were detached, counted, and compared to untreated controls. Melatonin and its membrane receptor agonists (Mel1a-1b and Mel1b), but not its putative nuclear receptor agonist (Mel2), inhibited the growth of uveal melanoma cells, but not normal melanocytes, at very low concentrations. In uveal melanoma cells, the expression of RNA encoding the Mel1b receptor suggests that the growth inhibiting effect of melatonin on uveal melanoma cells is related to activation of the melatonin Mel1b membrane receptor. Furthermore, the expression of RNA encoding melatonin receptors in normal uveal melanocytes suggests that melatonin may play a role in the function of these cells.

Effect of prostaglandins A(2), E(1), F(2 alpha)and latanoprost on cultured human iridal melanocytes

The effect of various prostaglandins on the growth, melanogenesis and dendrification of cultured iridal melanocytes were studied. Iridal melanocytes were isolated and cultured with medium supplemented with cAMP elevating agents and basic fibroblast growth factor (complete medium). The iridal melanocytes were plated into multiple well plates and cultured with complete medium, cAMP-deleted medium with or without various prostaglandins at different concentrations. After 5-7 days, the numbers of cells and dendrites were counted and melanin content was measured and compared to controls. Prostaglandin A(2)and E(1)stimulated growth, melanogenesis and dendrification of cultured iridal melanocytes in cAMP-deleted medium. Prostaglandin F(2 alpha), PhXA85 and latanoprost showed no effect under similar experimental conditions. These results indicate that prostaglandin A(2)and E(1)stimulate growth and differentiation of iridal melanocytes through the activation of cAMP system. Failure of stimulation of melanogenesis of iridal melanocytes by prostaglandin F(2 alpha)and PhXA85 in vitro may be related to a different second messenger system activated by these prostaglandins and the selective stimulating effect of these prostaglandins on iridal melanocytes from mixed-colored irides.

Photophysical studies of A2-E, putative precursor of lipofuscin, in human retinal pigment epithelial cells

With age, human retinal pigment epithelial cells accumulate lipofuscin that can absorb photons in the visible range leading to light-induced damage and impaired vision. A putative precursor of lipofuscin, 2-[2,6-dimethyl-8-(2,6,6-trimethyl-1-cyclohexen-1-yl)-1E,3E, 5E,7E- octatetraenyl]-1-(2-hydroxyethyl)-4-[4-methyl-6-(2,6,6-trimethyl-1 - cyclohexen-1-yl)-1E,3E,5E-hexatrienyl]-pyridinium (A2-E), has recently been isolated and characterized from aged human retinal pigment epithelial cells. We have found that A2-E inhibits the growth of human retinal pigment epithelial cells at concentrations greater than 1 microM. Time-resolved fluorescence measurements of 1 microM A2-E in solution, performed under 413 nm excitation, showed that fluorescence wave forms integrated across the spectrum (450-600 nm) were best-fitted with three decay times in the nanosecond and subnanosecond time scale: 6.6, 1.9 and 0.33 ns. Untreated retinal pigment epithelial cells were characterized by three fluorescence lifetimes: 6.3, 1.7 and 0.35 ns. In retinal pigment epithelial cells treated with 1 microM A2-E, the fluorescence decay was significantly faster, with the marked presence (approximately equal to 30%) of a fourth short lifetime (0.12 ns). These fluorescence decay times for A2-E bound to human retinal pigment epithelial cells are similar to those of lipofuscin granules isolated from aged human retinal pigment epithelial cells. This similarity supports the hypothesis that A2-E is a precursor of lipofuscin and suggests that A2-E may play a role in the overall light damage associated with age-related retinal diseases.

The identification and differential expression of calcium-binding proteins associated with ocular melanoma

Calcium-binding proteins may endow tumor cells with properties related to their malignancy and metastatic phenotype. Chromatographic procedures and amino acid sequence analysis were used in this study to identify seven calcium-binding proteins, annexin VI, cap g, annexin V, calmodulin, S100A11, S100B and S100A6, associated with uveal melanoma, the primary ocular tumor of adults. This series of calcium-binding proteins was identified in both primary tumors and cell lines of uveal melanoma. Several of the proteins were shown by immunochemical methods to be differentially expressed between normal uveal melanocytes and malignant melanomas of the uvea. In addition, the expression of S100A6 may correlate with the malignant properties of the tumor.

Characterization of melanins in human irides and cultured uveal melanocytes from eyes of different colors

The presence of eumelanin and pheomelanin in irides from eyes of various colors was determined and quantified by a highly specific microanalytical procedure based on chemical degradation. Significant differences in the type of melanin were observed in the stroma and iris pigment epithelium (IPE) fractions obtained by micro-dissection of the iris specimens. Melanin from the IPE is essentially eumelanin, while the pigment in IPE-scraped iris (consisting mainly of stroma plus anterior IPE) proved to be both eumelanic and pheomelanic. A pheomelanic-type pigmentation was associated with green irides, while green-blue mixed-color irides were mostly eumelanic; by contrast, green-brown mixed-color and brown irides could not be placed into either of the two categories and probably feature a mixed pigment content. Blue irides invariably exhibited very low pigment content. Analysis of cultured iridial melanocytes in the growing stage showed a significant shift to pheomelanic pigmentation when compared with those in IPE-scraped tissues, providing evidence that growth of iridial melanocyte induce a marked change of melanin metabolism. After senescence, cultured melanocytes exhibited a marked increase in pigment content, most of the variation was associated with the eumelanin content. These results represent the first direct evidence for the presence of eumelanin and pheomelanin in human irides, and suggest that differences in stromal pigmentation are due not only to the quantity, but also the nature of the melanin pigment.

TGF-beta2 inhibits growth of uveal melanocytes at physiological concentrations

The effect of TGF-beta2 on growth of uveal melanocytes in vitro was studied and the dose-dependent inhibitory effect of TGF-beta2 was compared with the known concentration of TGF-beta2 in aqueous humor. Uveal melanocytes were isolated and cultured with medium supplemented with cAMP elevating agents and basic fibroblast growth factor. The uveal melanocytes were plated into multi-well plates. After 24 hr, TGF-beta2 was added to the medium in various concentrations. After 5 days, the cells were detached, counted and compared to the controls. The effect of TGF-beta2 on DNA synthesis (as evaluated by uptake of bromodeoxyuridine) were also tested. TGF-beta2 inhibited growth and DNA synthesis of cultured uveal melanocytes in a dose-dependent manner at concentrations from 0.03-10.0 ng ml-1. The growth-inhibition of TGF-beta2 was present even in serum-free medium. TGF-beta2 had little or no effect on melanogenesis of cultured uveal melanocytes. The serum used for cultivation did not contain active TGF-beta1 or TGF-beta2 as measured by immunoassay. The known amount of active TGF-beta2 in aqueous humor (0.2-0.4 ng ml-1) is sufficient to inhibit the growth of uveal melanocytes. It indicates that TGF-beta2 is a potent growth inhibit factor of uveal melanocytes and may play an important role in maintaining the non-proliferative, relatively quiescence status of uveal melanocytes in vivo.

Effects of melatonin, its precursors and derivatives on the growth of cultured human uveal melanoma cells

The effects of melatonin, its precursors and derivatives on the growth of cultured human uveal melanoma cells were studied. The melanoma cells were plated into 24-well plates. Melatonin, its 6-hydroxy or 6-chloro derivative, serotonin, tryptophan or kynurenine was added to the medium in concentrations of 0.001 to 1000 nM. After 5 days the cells were detached, counted, and compared with the controls. Melatonin inhibited the growth of uveal melanoma cell lines in a dose-dependent manner (0.1-10 nM). This growth inhibition occurred at concentrations of melatonin (2 nM) found in human aqueous humour. The melatonin derivatives also inhibited the growth of uveal melanoma cells; 6-chloromelatonin was more potent than melatonin and 6-hydroxymelatonin was the least active (6-chloromelatonin > melatonin > 6-hydroxymelatonin). The precursors of melatonin (tryptophan and serotonin) and the abnormal metabolite of tryptophan (kynurenine) did not inhibit the growth of the melanoma cells, indicating that changes to the metabolic processes of melatonin may play a role in the pathogenesis of uveal melanoma.

Pulse radiolysis studies of melatonin and chloromelatonin

The endogenous indole melatonin and the melatonin receptor agonist 6-chloromelatonin block the proliferation of both dermal and uveal melanoma cells by mechanisms that may involve redox reactions. The interactions of hydrated electrons, the azide radical, hydroxyl radicals and superoxide with melatonin and its 6-chloro analogue have been studied using the technique of pulse radiolysis. The reaction rate constants of eaq- and N3 x with these compounds were found to be dependent on substitution at the sixth position. The rate constants for reaction of 6-chloromelatonin and melatonin with solvated electrons are 4.5 x 10(9) M-1 s-1 and 4.2 x 10(8) M-1 s-1, respectively. The reaction rate constants of N3 x with malatonin and chloromelatonin are 9.8 x 10(9) M-1 s-1 and 3.5 x 10(9) M-1 s-1 and 3.5 x 10(9) M-1 s-1, respectively. Melatonin and 6-chloromelatonin react with hydroxyl radicals at near diffusion controlled rates (1.3 x 10(10) M-1 s-1, 8.2 x 10(9) M-1 s-1). Melatonin and 6-chloromelatonin did not react with superoxide radicals and we calculate an upper limit of 1.0 x 10(4) M-1 s-1 for the rate constant for reaction of melatonin and 6-chloromelatonin with superoxide ion.

Regulation of melanogenesis by human uveal melanocytes in vitro

The purpose of this study was to investigate factors regulating melanogenesis in cultured human uveal melanocytes. The effects of various substances on the melanin content, tyrosinase activity and growth of cultured uveal melanocytes were tested. 12-O-tetradecanoyl-phorbol-13-acetate (a protein kinase C activator) and various cAMP-elevating agents, including isobutylmethylxanthine, cholera, toxin, and dibutyryl-cAMP increased melanin content per culture, tyrosinase activity and cell numbers of uveal melanocytes in a dose dependent manner. Basic fibroblast growth factor (tyrosine kinase activator) stimulated growth but did not affect melanin content per culture of uveal melanocytes in vitro. These results indicate that cAMP-elevating agents and protein kinase C activator stimulate melanogenesis and growth of cultured uveal melanocytes. Tyrosine kinase activator stimulates growth but not melanogenesis of cultured uveal melanocytes.

Tissue culture of adult human retinal ganglion cells

PURPOSE

We wished to isolate and cultivate adult human retinal ganglion cells (RGC) from donor eyes.

METHODS

Small pieces of retina from donor eyes were plated in dishes and cultured with Ham's F12 medium with 10% serum for organ culture. For cell culture, cells were isolated by mechanical or enzymatic dissociation methods and cultured with F12 medium with 10% serum, with or without nerve growth factor (NGF) and/or basic fibroblast growth factor (bFGF).

RESULTS

In organ cultures, no neurite outgrowth from the retinal explants was observed. In cell cultures for which mechanical dissociation methods were used, the few cells that could be isolated showed poor viability. Better results were obtained with enzymatic dissociation methods. When cultured with medium supplemented with bFGF, some cells attached, spread, and sent out numerous dendrites, morphologically similar to RGC. These cells stained positively for neurofilaments and Thy-1 and negatively for glial fibrillary acidic protein (GFAP), indicating they were RGC.

CONCLUSIONS

Cell cultures of human RGC can be established. This is a potential model system for studying effects of damaging and protective factors on RGC in vitro.

Melatonin inhibits growth of cultured human uveal melanoma cells

The effects of melatonin on the growth of human uveal melanoma cells were studied in vitro. Three continuous uveal melanoma cell lines were tested. Cells were plated into multi-well plates. After 24 h, melatonin was added to the medium at concentrations from 0.001 to 1000 nM. Cells were collected and counted after 5 days and compared with the controls. Melatonin inhibited the growth of melanoma cells in a dose-dependent manner (0.1-10 nM) with a mean inhibition rate of 50%. The uptake of bromodeoxyuridine (BrdU) by the melanoma cells was also measured. Melatonin inhibited the uptake of BrdU of melanoma cells at concentrations of 0.1-10 nM with a mean inhibition rate of 40%. These results indicate that melatonin may offer a new treatment for metastatic uveal melanoma.

Isolation and culture of iris pigment epithelium from iridectomy specimens of eyes with and without exfoliation syndrome

OBJECTIVE

To culture iris pigment epithelium (IPE) from surgical iridectomy specimens of eyes with and without exfoliation syndrome.

METHODS

The IPE was treated to obtain a single cell suspension. Cells were cultured in Ham F12 nutrient mixture, which was supplemented with 30% fetal bovine serum, 50-micrograms/mL [corrected] gentamicin, and 2-mmol/L glutamine. After confluence, the cells were detached using a 0.125% trypsin-0.01% edetic acid solution, resuspended, diluted, and subcultured. The IPE from primary cultures and subcultures was studied by transmission electron microscopy. Immunocytochemical staining was performed.

RESULTS

In the primary cultures of IPE from patients with exfoliation syndrome, curved, cross-banded, fine fibrils (diameter, 10-15 nm; periodicity, 10-14 nm) were found on the cell surface. Thicker fibrils (diameter, 24-48 nm; periodicity, 24-36 nm) were found external to the fine fibrils. Subcultures contained mainly fine fibrils. The IPE cells stained positively with anticytokeratin, S100 protein, and vimentin antibodies.

CONCLUSION

Iris pigment epithelium can be successfully cultured from eyes with exfoliation syndrome. Studying the production of exfoliation material in vitro should provide information about the pathogenesis of exfoliation syndrome and about the nature of the exfoliation material. The cultivation of normal IPE from surgical specimens provides a source for the study of the growth regulation and pharmacophysiology of IPE in vitro.

Melanogenesis by human uveal melanocytes in vitro

PURPOSE

To study melanogenesis by cultured human uveal melanocytes, and the relationship between melanin production by uveal melanocytes in vitro with the degree of iris pigmentation in vivo.

METHODS

Melanin content, melanin production, and tyrosinase activity of cultured uveal melanocytes derived from eyes of various iris color were measured at different stages of cultivation.

RESULTS

Cultured uveal melanocytes maintained a constant level of melanin content, expressed tyrosinase activity, and produced measurable amounts of melanin in vitro. Melanosomes in different stages were seen ultrastructurally. Melanin production correlated directly with the degree of iris pigmentation of the eyes from which the uveal melanocytes were isolated. Tyrosinase activity of cultured uveal melanocytes from black versus white donors was significantly different, but, among white donors, there was no correlation with iris pigmentation or with melanin production in vitro.

CONCLUSION

Cultured uveal melanocytes can produce melanin in vitro. Cultured uveal melanocytes isolated from eyes of different iris color maintained their inherent capacity for melanogenesis. Therefore, cultured uveal melanocytes are an excellent model system for studying melanogenesis in uveal melanocytes in vitro.

Studies of human uveal melanocytes in vitro: isolation, purification and cultivation of human uveal melanocytes

PURPOSE

To develop the methods for isolation and cultivation of human uveal melanocytes (UM) from adult donor eyes.

METHODS

After removal of the pigment epithelium, the uvea was pretreated in trypsin solution at 4 degrees C overnight, incubated at 37 degrees C with trypsin for 1 hr, then incubated with collagenase for 3 hr. Released cells were collected each hour during the incubation and cultured with F12 medium supplemented with fetal bovine serum, basic fibroblast growth factor, isobutylmethylxanthine and cholera toxin. Contaminant cells were eliminated by adding a selective cytotoxic agent, geneticin, when necessary.

RESULTS

These methods provide pure melanocyte cultures with high cell yields, good viability, and rapid growth rates. UM isolated and maintained using these methods can be passaged 23 times for a period of 7 mo for more than 35 population doublings. This is comparable to results obtained with cultured neonatal dermal melanocytes and exceeds results obtained with adult dermal melanocytes cultured in media supplemented with phorbol ester, isobutylmethylxanthine, and cholera toxin.

CONCLUSION

A method for isolation and cultivation of UM has been developed that yields satisfactory results. Cultured UM may be useful in in vitro studies of UM physiology and may allow development of in vitro models of the pathogenesis of uveal malignant melanoma.

Studies of human uveal melanocytes in vitro: growth regulation of cultured human uveal melanocytes

PURPOSE

The authors studied the growth requirements and growth regulation of cultured human adult uveal melanocytes (UM).

METHODS

The effect of various mitogens and growth factors on the growth of UM were tested separately or combined on cultured UM in multiwell plates.

RESULTS

Basic fibroblast growth factor (bFGF) and 12-O-tetradecanoyl-phorbol-13-acetate (TPA) stimulate the growth of UM. Without these agents, the UM did not grow or survive. A cyclic adenosine monophosphate (cAMP) stimulator, such as isobutylmethylxanthine or cholera toxin, stimulated growth in the presence of bFGF. Fetal bovine serum (FBS) is also required for growth. In its absence, UM did not grow, even in the presence of bFGF and cAMP stimulators. Other substances, such as epidermal growth factor, acidic FGF, nerve growth factor, and platelet-derived growth factor had no stimulating effects on the growth of UM.

CONCLUSIONS

Three classes of agents are required for the growth of UM in vitro: bFGF or TPA, a cAMP stimulator, and FBS. Adult human UM cultured in medium containing all these agents grew well and could be passaged for many generations.

Cleft lip with or without cleft palate in Shanghai, China: evidence for an autosomal major locus

Orientals are at higher risk for cleft lip with or without cleft palate (CL +/- P) than Caucasians or blacks. We collected demographic and family data to study factors contributing to the etiology of CL +/- P in Shanghai. The birth incidence of nonsyndromic CL +/- P (Shanghai 1980-87) was 1.11/1,000, with a male/female ratio of 1.42. Almost 2,000 nonsyndromic CL +/- P probands were ascertained from individuals operated on during the years 1956-83 at surgical hospitals in Shanghai. Detailed family histories and medical examinations were obtained for the probands and all available family members. Genetic analyses of the probands' families were performed under the mixed model with major locus (ML) and multifactorial (MFT) components. The hypotheses of no familial transmission and of MFT alone could be rejected. Of the ML models, the autosomal recessive was significantly most likely and was assumed for testing three complex hypotheses: (1) ML and sporadics; (2) ML and MFT; (3) ML, MFT, and sporadics. None of the complex models were more likely than the ML alone model. In conclusion, the best-fitting, most parsimonious model for CL +/- P in Shanghai was that of an autosomal recessive major locus.

Isolation and cultivation of human iris pigment epithelium

There have been very few attempts to isolate and culture human iris pigment epithelium (IPE). Earlier efforts that used whole iris explant methods did not achieve pure cultures of IPE. We have developed methods for separating the IPE from the iris stroma of post-mortem eyes that avoid contamination by other cell types. Three different isolation methods were studied: direct dissection, enzyme digestion, and enzyme-assisted microdissection. The latter method yielded the best results. After treatment with enzyme solution, the IPE was easily separated from the stroma under the stereomicroscope and subsequently cultured with supplemented F12 medium. With this method, approximately 2.3 x 10(5) cells were isolated from each iris with an average viability of 90.2%. IPE cells isolated from 19 of 24 eyes grew to confluence in primary culture. The IPE could be maintained in pure culture for many generations over several months with up to 20 population doublings. Cultured IPE demonstrated cytokeratin and S-100 protein by immunocytochemistry. Some of these cells also displayed desmin, indicating origin from the anterior IPE. Cultured IPE cells retained most of the characteristics of IPE in vivo, such as apical/basal polarization, microvilli, and many cell junctions. Gradual dilution of pigment occurred in the dividing IPE cells, suggesting an inability to produce melanin in vitro. A subpopulation of the IPE cells contained myofilaments by electron microscopy, also indicating a anterior IPE origin. This method provides a source for large numbers of human IPE cells and could be useful in studies of the biology of IPE and the role of IPE in pathogenesis of several eye diseases, most notably exfoliation syndrome and its associated glaucomas.

Genetic aspects of antibiotic induced deafness: mitochondrial inheritance

Analysis of 36 pedigrees with a positive family history of aminoglycoside antibiotic induced deafness, ascertained in a population of 483,611 in Zhabei District in Shanghai, showed that the susceptibility to antibiotic ototoxicity was transmitted by females exclusively, indicating mitochondrial inheritance. Reanalysis of 18 other published pedigrees confirmed this conclusion.

Prevalence and mode of inheritance of major genetic eye diseases in China

The prevalence and mode of inheritance of major genetic eye diseases have been investigated in China since the establishment of the Section of Ophthalmic Genetics of the Chinese Society of Genetics. Mass screening of genetic eye diseases has been undertaken in many districts in China, covering more than 700,000 people, and more than 5000 pedigrees of genetic eye diseases have been collected and analysed all over China. Based on these data, the prevalence and mode of inheritance of dyschromatopsia, degenerative myopia, retinitis pigmentosa, congenital ptosis, congenital microphthalmos, congenital cataract, congenital glaucoma, Leber's optic atrophy, corneal dystrophy, congenital nystagmus, coloboma of the eye, congenital aniridia, retinoblastoma, macular dystrophy, simple myopia, primary glaucoma, and strabismus have been investigated, and the results are presented.

Prevalence and genetic aspects of deaf mutism in Shanghai

Two hundred and eighty-five cases of congenital deaf mutism were ascertained in a population of 483,611 in Zhabei District in Shanghai. The prevalence was 0.059% (1:1697). Inherited cases accounted for 84.83% of all cases. The mode of inheritance was autosomal recessive with complete penetrance and heterogeneity (consisting of at least five different loci). The fitness was 77.63%, the coefficient of selection was 0.2237, the mutation rate was 1.119 x 10(-4) mutation/gamete, and no heterozygote advantage was proven.

Genetic analysis of cleft lip with or without cleft palate in Chinese kindreds

Cleft lip with or without cleft palate (CL +/- P) affects 1 in 500-1,000 newborns worldwide; the cause remains unclear. For CL +/- P, Asians are at higher risk than Caucasians or Blacks. This report presents the results of a genetic analysis of 163 CL +/- P proband families ascertained in Shanghai, China. Based on statistical tests of several predictions from the classical multifactorial/threshold model, no evidence could be found to support it. Further, goodness-of-fit (PGOODFIT) tests of this model were also unsupportive, there being more families with two or more affected sibs than expected. Classical segregation analysis for Mendelian inheritance showed a maximum likelihood estimate of the segregation ratio of 0.187 +/- 0.068. This value was not significantly less than 0.25 (recessive inheritance) but was significantly less than 0.50 (dominant inheritance). Sex ratio data from these Chinese families suggest that manifestation of the putative single major gene is sex influenced. The apparent reduced penetrance is likewise to be expected if manifestation of CL +/- P also depends on in utero exposure to deleterious environmental agents, as demonstrated in a variety of human and animal model studies.

Genetics of cleft lip and cleft palate in China

During the past 10 years, 60 cases of cleft lip with or without cleft palate [CL(P)] were recorded among 45,072 newborns at Shanghai International Peace Maternity and Infant Hospital, China. The incidence was 1.33 per 1,000 births. The family histories of 163 CL(P) patients were analyzed. The incidences of CL(P) in the first-, second-, and third-degree relatives of CL(P) patients were 11/246 (4.47%), 10/1,032 (0.97%), and 6/1,727 (0.35%), respectively. Of the 163 probands, three had a history of consanguinity of the parents (1.8%), in contrast to 0.77% in the general population. These data are suggestive of multifactorial inheritance. The heritability of CL(P) in our study calculated by Falconer's formula was 77.6%.

Genetic aspects of retinitis pigmentosa in China

We analyzed 151 pedigrees (209 cases) of retinitis pigmentosa in Shanghai, China. Of the 209 cases, the proportion of autosomal recessive (AR), autosomal dominant (AD), X-linked recessive (XR), and simplex cases is 33.1, 11, 7.7, and 48.3% respectively. The average age of onset was 24.7 years in the AD type, 22.9 years in the AR and five years in the XR type. The average refractive errors were -1.88 D in the AD type, -2.37 D in the AR type, and -5.72 D in the XR type. In addition, 24,100 persons were screened and six cases of retinitis pigmentosa were found. The gene frequencies of the AR (including simplex cases), AD, and XR types as calculated from the disease prevalence were 0.0142267, 0.0000137, and 0.0000384, respectively. The gene frequency of the AR type as calculated from the frequency of consanguinity (15.9%) was 0.00389, which is much less than that calculated from the prevalence. The probable explanation is that the AR type of retinitis pigmentosa really consists of several different disease entities, with each entity representing a separate gene mutation. The number of different mutations within the AR group is estimated to lie between 11 and 41.