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PubMed2001

Biogenic production of cyanide and its application to gold recovery.

Chromobacterium violaceum is a cyanogenic (cyanide-producing) microorganism. Cyanide is used on an industrial scale to complex and recover gold from ores or concentrates of ores bearing the precious metal. A potentially useful approach in gold mining operations could be to produce cyanide biologically in relatively small quantities at the ore surface. In this study, C. violaceum grown in nutrient broth formed a biofilm and could complex and solubilize 100% of the gold on glass test slides within 4-7 days. Approximately 50% of the cyanide- recoverable gold could be mobilized from a biooxidized sulfidic-ore concentrate. Complexation of cyanide in solution by gold appeared to have a beneficial effect on cell growth--viable cell counts were nearly two orders of magnitude greater in the presence of gold-coated slides or biooxidized ore substrates than in their absence. C. violaceum was cyanogenic when grown in alternative feedstocks. When grown in a mineral salt solution supplemented with 13.3% v/v swine fecal material (SFM), cells exhibited pigmentation and suspended cell concentrations comparable to cultures grown in nutrient broth. Glycine supplements stimulated production of cyanide in 13.3% v/v SFM. In contrast, glycine was inhibitory when added at the time of inoculation in the more concentrated SFM, decreasing cell numbers and reducing ultimate bulk-solution cyanide concentrations. However, aeration and addition of glycine to stationary phase cells grown on 13.3% v/v SFM anaerobically resulted in rapid production and high concentrations (up to 38 mg l(-1)) of cyanide. This indicates that biogenesis of cyanide may be supported in remote areas using locally produced and inexpensive agricultural feedstocks in place of commercial media.

Animals↗
PubMed2005

Chemiluminescence accompanied by the reaction of gold nanoparticles with potassium permanganate.

It was found that potassium permanganate (KMnO(4)) could react with gold nanoparticles in a strong acid medium to generate particle size-dependent chemiluminescence (CL). For gold nanoparticles with the size of 2.6 or 6.0 nm, the reaction was fast and could produce the excited state Mn(II) with light emission around 640 nm. For gold nanoparticles larger than 6.0 nm, no light emission was observed due to a much slower reaction rate. The CL intensity was found to increase linearly with the concentration of 2.6 nm gold nanoparticles. The effects of the acid medium, concentration of KMnO(4) and presence of N(2) and O(2) were investigated. UV-Vis absorption spectra and X-ray photoelectron spectra (XPS) measured before and after the CL reaction were analyzed. A CL mechanism has been proposed suggesting that the potassium permanganate was reduced by gold nanoparticles in the strong acid medium to the excited state Mn(II), yielding light emission. The results bestow new light on the size-dependent chemical reactivities of the gold nanoparticles and on nanoparticle-induced chemiluminescence. The CL reaction was considered to be of potential use for bioanalysis applications.

Biosensing Techniques↗
PubMed2006

Subfemtomolar electrochemical detection of target DNA by catalytic enlargement of the hybridized gold nanoparticle labels.

After showing the failure of conventional gold-enhancement procedures to amplify the gold nanoparticle-based electrochemical transduction of DNA hybridization in polystyrene microwells, a new efficient protocol was developed and evaluated for the sensitive quantification of a 35 base-pair human cytomegalovirus nucleic acid target (tDNA). In this assay, the hybridization of the target adsorbed on the bottom of microwells with an oligonucleotide-modified Au nanoparticle detection probe (pDNA-Au) was monitored by the anodic stripping detection of the chemically oxidized gold label at a screen-printed microband electrode (SPMBE). Thanks to the combination of the sensitive Au(III) determination at a SPMBE with the large amount of Au(III) released from each pDNA-Au, picomolar detection limits of tDNA can be achieved. Further enhancement of the hybridization signal based on the autocatalytic reductive deposition of ionic gold (Au(III)) on the surface of the gold nanoparticle labels anchored on the hybrids was first envisaged by incubating the commonly used mixture of Au(III) and hydroxylamine (NH(2)OH). However, due to a considerable nonspecific current response of poor reproducibility it was not possible to significantly improve the analytical performances of the method under these conditions. Complementary transmission electronic microscopy experiments indicated the loss of most of the grown gold labels during the post-enlargement rinsing step. To circumvent this drawback, a polymeric solute containing polyethyleneglycol and sodium chloride was introduced in the growth media to act as an aggregating agent during the catalytic process and thus retain the enlarged labels on the bottom of the microwell. This strategy, which led to an efficient increase of the hybridization response, allowed detection of tDNA concentrations as low as 600 aM (i.e., 10(4) lower than without amplification), and thus offers great promise for ultrasensitive detection of other hybridization events.

Catalysis↗
PubMed1987

The detection of substructures within proteoglycan molecules. Electron-microscopic immuno-localization with the use of Protein A-gold.

Proteoglycan monomers from pig laryngeal cartilage were examined by electron microscopy with benzyldimethylalkylammonium chloride as the spreading agent. The proteoglycans appeared as extended molecules with a beaded structure, representing the chondroitin sulphate chains collapsed around the protein core. Often a fine filamentous tail was present at one end. Substructures within proteoglycan molecules were localized by incubation with specific antibodies followed by Protein A-gold (diameter 4 nm). After the use of an anti-(binding region) serum the Protein A-gold (typically one to three particles) bound at the extreme end of the filamentous region. A small proportion of the labelled molecules (10-15%) showed the presence of gold particles at both ends. A monoclonal antibody specific for a keratan sulphate epitope (MZ15) localized a keratan sulphate-rich region at one end of the proteoglycan, but gold particles were not observed along the extended part of the protein core. This distribution was not changed by prior chondroitin AC lyase digestion of the proteoglycan. Localization with a different monoclonal antibody to keratan sulphate (5-D-4) caused a change in the spreading behaviour of a proportion (approx. 20%) of the proteoglycan monomers that lost their beaded structure and appeared with the chondroitin sulphate chains projecting from the protein core. In these molecules the Protein A-gold localized antibody (5-D-4) along the length of the protein core whereas in those molecules with a beaded appearance it labelled only at one end. Labelling with either of the monoclonal antibodies was specific, as it was inhibited by exogenously added keratan sulphate. The differential localization achieved may reflect structural differences within the proteoglycan population involving keratan sulphate and the protein core to which it is attached. The results showed that by this technique substructures within proteoglycan molecules can be identified by Protein A-gold labelling after the use of specific monoclonal or polyclonal antibodies.

Animals↗
PubMed2003

[Are titanium implants superior to gold implants in the tympanic cavity?].

BACKGROUND: Gold implants in reconstructive surgery of the middle ear have proved to work sufficiently: That applies to tympanic cavity conditions without signs of chronic inflammation as also to the bacterially infected middle ear. For some years titanium implants are also in the use and established as well. The biocompatibility of titanium, the clinical and the audiological results are satisfactory. When using gold-prostheses in stapes surgery however, the still unsolved problem of occasional deafness has to be considered. PATIENTS: The clinical and functional results of middle ear surgery were examined retrospectively. There was no preselection of patients. 53 patients underwent middle ear surgery with titanium prostheses, 42 patients with gold prostheses. RESULTS: Due to their material properties and due to their delicate shape titanium prostheses (PORP, TORP) can be inserted into the tympanic cavity more simply and with better fit. The audiological results of gold and titanium prostheses are comparable. The extruding rate of the gold prostheses is substantial, whereas the extruding rate of titanium is negligible. CONCLUSION: The functional results of both materials are comparable. Due to the high extruding rates of gold prostheses titanium is clearly superior.

Auditory Threshold↗
PubMed2007

[Results after lidloading with rigid gold weights--a meta-analysis].

INTRODUCTION: For the surgical therapy of lagophthalmos rigid gold implants were used. There are a lot of studies using rigid gold implants with widely different complications. In the primary study the small amount of patients is often a problem. The aim of our study was to survey the postoperative results and complications after insertion of rigid gold implants and to statistically compare the results with a meta-analysis. MATERIAL AND METHODS: 38 publications on 1000 rigid gold implants were analyzed in the context of a meta-analysis of the postoperative results. RESULTS: Complete lid closure can be obtained in 84.5 % with the rigid gold implants. The postoperative complication rates were 13.4 % for bulging, 6.4 % for migration, 6.8 % for extrusion, 11.5 % for corneal astigmatism and 7.0 % postoperative infections. DISCUSSION: Lidloading is a very simple and reversible procedure for the surgical treatment of lagophthalmos. The statistical analysis in using rigid gold implants showed a significant rate of postoperative complications. To increase the effectivity of the treatment method these results should be taken into account for alternative implants.

Eyelid Diseases↗
PubMed2001

Operator-induced compressive axial forces during implant gold screw fastening.

STATEMENT OF PROBLEM: The gold screw of an implant is put under tension during fastening. An increase in operator-induced compressive axial force during fastening may diminish screw tension, lower the friction between the screw threads, and allow for increased tightening torque. PURPOSE: This study was undertaken to assess and compare the compressive axial forces and torques placed simultaneously on implant gold screws by persons with varying degrees of expertise. MATERIAL AND METHODS: A calibrated electric torque driver was used to fasten implant gold screws. Three groups of operators with various levels of implant experience (faculty [F; n = 4], prosthodontic residents [R; n = 4], and undergraduate dental students [S; n = 6]) were asked to repeatedly tighten and loosen a new gold abutment screw into a standard 3.75-mm diameter Branemark abutment. Compressive axial forces during torquing were assessed over the tightening time by means of a miniature load cell adapted to the electric torque driver. Each operator repeated the experiment 3 times after calibration. Within operator and between operator reliability were evaluated. RESULTS: Loosening compressive axial forces were always higher than tightening compressive axial forces, and peak torque was less on loosening than tightening. Faculty placed a smaller range of forces on the screws (mean = 3.29 N, SD +/- 1.45 N) than did the residents (mean = 2.74 N, SD +/- 1.96) or the students (mean = 3.01 N, SD +/- 2.54). CONCLUSION: The clinical experience of operators seems to influence their application of compressive axial force during gold screw tightening. Less torque during unfastening of gold screws seems to be related to increased axial loading.

Analysis of Variance↗
PubMed1981

Colloidal gold--low density lipoprotein conjugates as membrane receptor probes.

We have developed a method for conjugating low density lipoproteins (LDL) with colloidal gold. Conjugation, complete after 1 min, occurs by electrostatic adsorption of the LDL to the negatively charged gold particle. Each conjugate consists of approximately eight biologically active LDL molecules clustered around a central 19-nm gold granule. Acidic (pH 4), alkaline (pH 9), or high ionic (600 milliosmolar NaCl) environments do not dissociate the conjugate. Colloidal gold is an electron-dense, nondegradable marker that is easily identified within the cell and serves as a valuable probe for studying receptor binding and endocytosis. By using a modified method of ruthenium red staining, the LDL molecules of the conjugate can be directly visualized when they are bound to the cell surface receptor. Receptor binding (4 degrees C) of the conjugate by cultured human fibroblasts reveals that the gold granule is positioned 18-21 nm from the coated pit region of the membrane. This distance, similar to the diameter of LDL, suggests concomitant internalization of the receptor during vesicular endocytosis and early lysosomal incorporation (10 min at 37 degrees C). Continued internalization (30-60 min at 37 degrees C) results in the formation of free pools of gold within the lysosome.

Cell Membrane↗
PubMed1985

Uptake of gold- and [3H]cholesteryl linoleate-labeled human low density lipoprotein by cultured rat granulosa cells: cellular mechanisms involved in lipoprotein metabolism and their importance to steroidogenesis.

We used electron microscopy, acid hydrolase cytochemistry, and biochemistry to analyze the uptake and metabolism of colloidal gold- and [3H]cholesteryl linoleate-labeled human low density lipoprotein (LDL) by cultured rat granulosa cells. The initial interaction of gold-LDL conjugates with granulosa cells occurred at binding sites diffusely distributed over the plasma membrane. After incubation with ligand in the cold, 99.9% of the conjugates were at the cell surface but less than 4% lay over coated pits. Uptake was specific since it was decreased 93-95% by excess unconjugated LDL and heparin, but only 34-38% by excess unconjugated human high density lipoprotein. LDL uptake was related to granulosa cell differentiation; well-luteinized cells bound 2-3 times as much gold-LDL as did poorly luteinized cells. Ligand internalization was initiated by warming and involved coated pits, coated vesicles, pale multivesicular bodies (MVBs), dense MVBs, and lysosomes. A key event in this process was the translocation of gold-LDL conjugates from the cell periphery to the Golgi zone. This step was carried out by the pale MVB, a prelysosomal compartment that behaves like an endosome. Granulosa cells exposed to LDL labeled with gold and [3H]cholesteryl linoleate converted [3H]sterol to [3H]progestin in a time-dependent manner. This conversion was paralleled by increased gold-labeling of lysosomes and blocked by chloroquine, an inhibitor of lysosomal activity. In brief, granulosa cells deliver LDL to lysosomes by a receptor-mediated mechanism for the hydrolysis of cholesteryl esters. The resulting cholesterol is, in turn, transferred to other cellular compartments, where conversion to steroid occurs. These events comprise the pathway used by steroid-secreting cells to obtain the LDL-cholesterol vital for steroidogenesis.

Animals↗
PubMed1988

Translocation of RNA-coated gold particles through the nuclear pores of oocytes.

In the present study, various sized gold particles coated with tRNA, 5S RNA, or poly(A) were used to localize and characterize the pathways for RNA translocation to the cytoplasm. RNA-coated gold particles were microinjected into the nucleus of Xenopus oocytes. The cells were fixed after 15, 60 min, or 6 h, and the particle distribution was later observed by electron microscopy. Similar results were obtained with all classes of RNA used. After nuclear injection, particles ranging from 20-230 A in diameter were observed within central channels of the nuclear pores and in the cytoplasm immediately adjacent to the pores. Particles of this size would not be expected to diffuse through the pores, suggesting that some form of mediated transport occurred. In addition, it was found that the translocation process is saturable. At least 97% of the pores analyzed appeared to be involved in the translocation process. Gold coated with nonphysiological polynucleotides (poly[I] or poly[dA]) were also translocated. When nuclei were injected with either BSA-, ovalbumin-, polyglutamic acid-, or PVP-coated gold, the particles were essentially excluded from the pores. These results indicate that the accumulation of RNA-gold within the pores and adjacent cytoplasm was not due to non-specific effects. We conclude that the translocation sites for gold particles coated with different classes of RNA are located in the centers of the nuclear pores and that particles at least 230 A in diameter can cross the envelope. Tracer particles injected into the cytoplasm were observed within the nuclear pores in areas near the site of injection. However, only a small percentage of the particles actually entered the nucleus. It was also determined, by performing double injection experiments, that individual pores are bifunctional, that is, capable of transporting both proteins and RNA.

Animals↗
PubMed1993

Unconfined lateral diffusion and an estimate of pericellular matrix viscosity revealed by measuring the mobility of gold-tagged lipids.

Nanovid (video-enhanced) microscopy was used to determine whether lateral diffusion in the plasma membrane of colloidal gold-tagged lipid molecules is confined or is unrestricted. Confinement could be produced by domains within the plane of the plasma membrane or by filamentous barriers within the pericellular matrix. Fluorescein-phosphatidylethanolamine (F1-PE), incorporated into the plasma membranes of cultured fibroblasts, epithelial cells and keratocytes, was labeled with 30-nm colloidal gold conjugated to anti-fluorescein (anti-F1). The trajectories of the gold-labeled lipids were used to compute diffusion coefficients (DG) and to test for restricted motion. On the cell lamella, the gold-labeled lipids diffused freely in the plasma membrane. Since the gold must move through the pericellular matrix as the attached lipid diffuses in the plasma membrane, this result suggests that any extensive filamentous barriers in the pericellular matrix are at least 40 nm from the plasma membrane surface. The average diffusion coefficients ranged from 1.1 to 1.7 x 10(-9) cm2/s. These values were lower than the average diffusion coefficients (DF) (5.4 to 9.5 x 10(-9) cm2/s) obtained by FRAP. The lower DG is partially due to the pericellular matrix as demonstrated by the result that heparinase treatment of keratocytes significantly increased DG to 2.8 x 10(-9) cm2/s, but did not affect DF. Pericellular matrix viscosity was estimated from the frictional coefficients computed from DG and DF and ranged from 0.5 to 0.9 poise for untreated cells. Heparinase treatment of keratocytes decreased the apparent viscosity to approximately 0.1 poise. To evaluate the presence of domains or barriers, the trajectories and corresponding mean square displacement (MSD) plots of gold-labeled lipids were compared to the trajectories and MSD plots resulting from computer simulations of random walks within corrals. Based on these comparisons, we conclude that, if there are domains limiting the diffusion of F1-PE, most are larger than 5 microns in diameter.

Animals↗
PubMed2004

Identification of second harmonic optical effects from vaccine coated gold microparticles.

This study investigates the optical effects observed from uncoated and protein vaccine coated gold microparticles while imaging with two-photon excitation in the Mie scattering regime. When observed with time correlated single photon counting fluorescence lifetime microscopy, the emission from the gold microparticles appeared as an intense instrument-limited temporal response. The intensity of the emission showed a second-order dependence on the laser power and frequency doubling of the emitted light was observed for fundamental light between 890 and 970 nm. The optical effect was attributed to two-photon induced second harmonic generation. The vaccine coated gold microparticles had a much weaker second harmonic signal than the uncoated gold microparticles. Chemical analysis of the surface of the gold microparticles revealed that the vaccine coating decreases the surface charge thereby diminishing the observed second harmonic signal. These optical properties can be exploited to identify both the location of the protein vaccine coating as well as the gold microparticles in vitro and potentially to investigate the vaccine delivery kinetics in vivo.

Drug Delivery Systems↗
PubMed1992

Lipogranulomas and gold in the liver in rheumatoid arthritis.

Liver biopsies have been performed routinely as part of a protocol to evaluate methotrexate therapy in severe rheumatoid arthritis. All patients in the study had failed standard medical therapy, including gold treatment. Twenty-three of 41 patients (56%) had well-formed lipogranulomas (LGs) in the lobules, compared with an incidence of approximately 5% in our general biopsy population. Twenty-seven of 41 patients (66%) had a unique pigment in their livers. In 20 of these, the pigment was in LGs; in the seven patients with pigment not associated with lobular LG, it was found in lipid droplets in portal triads. The pigment varied from irregular pale brown granules slightly larger than those of hemosiderin, to smaller black round granules. Lipogranuloma-associated pigment of this type is an unusual finding, reminiscent of argyria. There was a variable appearance upon polarization, the black granules at times being strikingly refractile. There was a positive correlation between the prominence of LG and the quantity of pigment. The pigment resembled that described with gold deposition in other tissues. Radiographic microanalysis of both brown and black granules was performed in three cases. Characteristic spectra (energy-dispersive spectroscopy) demonstrated the presence of gold in each case. Silver was not identified. The high incidence of LG may reflect the frequent administration of gold in an oily vehicle. Gold may remain trapped in the liver for a prolonged time. Thus far, we have not detected any adverse effect from the presence of LG-associated gold.

Arthritis, Rheumatoid↗
PubMed1998

Synthesis and biological activity of gold and tin compounds in ovarian cancer cells.

We have investigated the patterns of in vitro cytotoxicity, induced by six newly synthesized gold and tin compounds, in three human ovarian cancer cell lines (SW 626, IGROV 1 and OVCAR-3). Four gold compounds, i.e. gold(I)lupinylsulfide hydrochloride [1] (containing a naked gold atom), triethylphosphinogold(I)lupinylsulfide hydrochloride [2], triphenyl-phosphinogold(I)lupinylsulfide hydrochloride [3] and 1 ,2-bis(diphenylphosphino)ethane bis[gold(I)lupinylsulfide] dihydrochloride [4] (all containing a gold atom coordinated with different phosphines), were prepared. Moreover, the triethylphosphinogold(I)(2-diethylamino)ethylsulfide hydrochloride [5] in which the simple diethylaminoethylthiol replaced the bulky lupinylthiol was synthesized. The tin compound, triethyltin(IV)lupinylsulfide hydrochlorlde [6], was also studied. Comparative tests with cisplatin, the most widely used antitumor agent in ovarian cancer, were carried out in biological Investigations. In vitro cytotoxicity, by MTT assay, showed that compound [4] and compound [6] exhibited interesting antiproliferative activity in all the three cell lines (mean IC50=1.3 and 0.7 microM, respectively) compared to cisplatin (mean IC50=4.8 microM). In addition, the PA-1 cell line, more sensitive to cisplatin (IC50=0.6 microM), was included as a comparison in the study. Cell count assays confirmed the cytotoxic properties of compounds [4] and [6] against the four cell lines, reporting higher growth Inhibition potency than cisplatin, with IC50 values in the sub-micromolar range.

Antineoplastic Agents↗
PubMed1978

Membranous nephropathy in patients with rheumatoid arthritis: relationship to gold therapy.

Of 90 patients with membranous nephropathy proved by biopsy, 8 (8.9%) had pre-existing rheumatoid arthirtis. Four of these eight patients received systemic treatment with gold. Two others received only token amounts of gold. In two patients who received gold, the renal lesions did not occur until months after discontinuance of gold therapy. We found that clinically significant renal lesions (lesions associated with proteinuria) in patients with rheumatoid arthritis were more likely to be membranous nephropathy than occult amyloidosis or adult lipoid nephrosis. The membranous lesion in patients with rheumatoid arthritis may be difficult to identify by light microscopy, and, although special strains can be helpful, the pathology is frequently sufficiently subtle to require immunofluorescence and electron microscopy for definitive diagnosis. We postulate that chrysotherapy may not be the cause of membranous nephropathy in patients with classic rheumatoid arthritis in whom gold has been used. Whether it merely exacerbates a lesion already present in these patients, or whether it plays little or no role in the development of membranous nephropathy is an unsettled question. Our data lead to think that RA can induce MN and that gold is not the primary inciting agent.

Adult↗
PubMed1995

The effect of cementing agent and technique on the retention of a CeraOne gold cylinder: a pilot study.

Endosseous dental implants are routinely used for the replacement of missing teeth. The CeraOne system uses a gold cylinder that is luted to a metal abutment. This study evaluated two luting agents and two luting techniques on the retention of a CeraOne gold cylinder to a CeraOne titanium abutment. A mechanical testing instrument was used to provide an uniaxial tensile force on the gold cylinder, which was cemented with zinc phosphate or Tempbond NE. The access opening to the gold abutment screw was filled or unfilled. Filling the access opening resulted in significantly higher retentive values (P < 0.01) compared to leaving the access opening unfilled. The gold cylinder was significantly more retentive when cemented with zinc phosphate as compared with Tempbond NE (P < 0.01). A Tukey post hoc test demonstrated that all means were significantly different at the P = 0.01 level. The results suggest that the choice of luting agent and luting technique may affect retention of a CeraOne gold cylinder.

Analysis of Variance↗
PubMed2003

Neurophysiological anomalies in brainstem responses of mercury-exposed children of Andean gold miners.

The health hazards of occupational exposure to Mercury (Hg) in adult gold miners are well known, but little attention has been given to the effects of Hg exposure in the children of gold miners. Children who assist their parents in gold mining operations or live in mining enclaves may be exposed to elemental Hg vapors or methylmercury-contaminated food, both of which may induce neurodevelopmental disabilities. Brainstem auditory-evoked responses (BAER) were measured as biomarkers of subtle mercury-induced neurological impairment in Andean children of gold miners living in the Ecuadorian gold mining settlement of Nambija, where Hg exposure is prevalent. Thirty-one children (19 boys and 12 girls, aged 4-14 years, mean age: 10 years) in the study group were found to have a mean blood mercury (HgB) level of 23.0 micrograms/L (SD: 19, range: 2.0-89.0 micrograms/L; median: 20 micrograms/L), which was significantly higher than the mean HgB level of a reference group of 21 Ecuadorian children (4.5 micrograms/L, SD: 2.3; t = 4.39, P = 0.0001), and in excess of the health-based biological limits for the U.S. (10 micrograms/L). The BAER measures indicated statistically significant differences in interpeak III-V (P = 0.03) and I-V (P = 0.008) neural conduction times for children with HgB levels above the median. BAERs at the conventional click stimulus rate of 10/second showed statistically significant positive correlations between HgB level and the absolute latency of wave V (P = 0.03), and the neural conduction times of the eighth nerve to midbrain I-V interval (P = 0.02). BAER at 50/second revealed statistically significant relationships between HgB and the latency of wave VI (P = 0.03), and the I-VI interpeak interval (P = 0.02). Brainstem neural conduction times suggested that some of the Hg-intoxicated children in the study group have subtle neurophysiological anomalies that may be more manifest at higher BAER stimulus rates, and that the Hg-exposed children of gold miners are at risk for neurodevelopmental disabilities.

Adolescent↗
PubMed2004

Processed human pericardium barrier for gold weight implantation.

PURPOSE: To determine the safety and efficacy of processed human pericardium as a barrier material for gold weight implantation. METHODS: In this retrospective, noncomparative case series, all patients undergoing gold weight implantation with human pericardium barrier between November 2000 and May 2002 were studied. Charts were reviewed for surgical indications, gold weight size, follow-up interval, and complications. RESULTS: Twenty-three eyelids of 23 patients underwent gold weight implantation with processed human pericardium barrier material. There were 15 female and 8 male patients. Mean patient age was 53 years (range, 22 to 78 years). Indications for surgery included extruded implant (4 eyelids), thin tissues overlying existing implant (3 eyelids), thin anterior lamellar eyelid tissues (6 eyelids), radiotherapy (1 eyelid), and requirement for long-term gold weight therapy (9 eyelids). Mean follow-up was 11 months (range, 3 to 36 months). Acceptable tissue coverage was found in 23 of 23 eyelids. There were no complications of infection, extrusion, or thinning of overlying tissues. One patient had prolonged eyelid edema and erythema that resolved spontaneously 3 months after surgery. CONCLUSIONS: Human pericardium appears to be well tolerated on at least a short-term basis within the eyelid when used as a barrier material for gold weight implantation.

Adult↗