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At least 631 records · Page 35Linked to original sources
PubMed1999

In vivo skin decontamination of methylene bisphenyl isocyanate (MDI): soap and water ineffective compared to polypropylene glycol, polyglycol-based cleanser, and corn oil.

In the home and workplace, decontamination of a chemical from skin is traditionally done with a soap-and-water wash, although some workplaces may have emergency showers. It has been assumed that these procedures are effective, yet workplace illness and even death occur from chemical contamination. Water, or soap and water, may not be the most effective means of skin decontamination, particularly for fat-soluble materials. This study was undertaken to help determine whether there are more effective means of removing methylene bisphenyl isocyanate (MDI), a potent contact sensitizer, from the skin. MDI is an industrial chemical for which skin decontamination, using traditional soap and water and nontraditional polypropylene glycol, a polyglycol-based cleanser (PG-C), and corn oil were all tried in vivo on the rhesus monkey, over 8 h. Water, alone and with soap (5% and 50% soap), were partially effective in the first h after exposure, removing 51-69% of the applied dose. However, decontamination fell to 40-52% at 4 h and 29-46% by 8 h. Thus, the majority of MDI was not removed by the traditional soap-and-water wash; skin tape stripping after washing confirmed that MDI was still on the skin. In contrast, polypropylene glycol, PG-C, and corn oil all removed 68-86% of the MDI in the first h, 74-79% at 4 h, and 72-86% at 8 h. Statistically, polypropylene glycol, PG-C, and corn oil were all better (p < 0.05) than soap and water at 4 and 8 h after dose application. These results indicate that a traditional soap-and-water wash and the emergency water shower are relatively ineffective at removing MDI from the skin. More effective decontamination procedures, as shown here, are available. These procedures are consistent with the partial miscibility of MDI in corn oil and polyglycols.

Administration, Topical↗
PubMed2002

Craniofacial reconstruction with computer-generated HTR patient-matched implants: use in primary bony tumor excision.

The aim of this clinical series is to report the effectiveness and safety of using computer-generated alloplastic hard tissue replacement (HTR) implants for the reconstruction of large defects of the cranio-orbital region when combined with simultaneous bone tumor excision. Seven patients who had large nonmalignant bony lesions of the anterior cranial vault and orbit underwent simultaneous bony excision and reconstruction with preoperatively fabricated custom alloplastic implants. Preoperatively, a 3D computed tomography (CT) scan was obtained from which an anatomical model was fabricated. On the anatomical model, the predicted amount of bone excision was performed. The defect in the model was then used to create an alloplastic (HTR polymer) implant for reconstruction and surgical placement. At the time of surgery, the implant was secured into position with either metal or resorbable plates and screws. In cases where the frontal sinus was in proximity to the implant, it was either cranialized and covered with a pericranial flap or obliterated with hydroxyapatite cement. All computer-generated implants required some modification intraoperatively due to a larger amount of bony excision than was preoperatively planned. This was accomplished by modifying the sterile back-up of the implant as an addition to the original implant or completing reconstruction of the bony defect with hydroxyapatite cement. All patients have healed uneventfully with a minimum of 1 year follow-up (average, 2.6 years). In all cases, excellent contours have been maintained and all patients have remained infection-free. In the management of large benign bony tumors of the cranio-orbital region, simultaneous reconstruction with custom implants fabricated from porous, hydrophilic HTR polymer can be preoperatively fabricated based on an estimate of the subsequent bony defect. The successful use of this approach depends on a favorable tissue quality of the recipient site, a generous preoperative estimate of the amount of bone that will be resected so that the implant is adequate, intraoperative techniques of expanding the implant reconstruction, and intraoperative methods to assure a partitioning of the implant from the frontal sinus.

Absorbable Implants↗
PubMed1996

Sucralfate and basic fibroblast growth factor promote endothelial cell proliferation around porous alloplastic implants in vitro.

Enhanced ingrowth of fibrovascular tissue into alloplastic orbital implants is clinically desirable. Basic fibroblast growth factor (bFGF) is an angiogenic factor that promotes proliferation of endothelial cells. Sucralfate is known to bind bFGF and render it stable by protecting it from degradation. To test the ability of bFGF to stimulate endothelial cell proliferation, porous orbital implants coated with a sustained-release and bioactively-stabilized preparation of the angiogenic peptide bFGF were studied. Hydroxyapatite (HA) and porous polyethylene (PP) implant discs (15 x 3 mm) were coated with sustained-release polymer polyhydroxyethylmethacrylate (hydron), sucralfate (a bFGF stabilizer), hydron plus or hydron/sucralfate plus bFGF. Discs were placed in tissue culture wells plated with 50,000 endothelial cells/well. After 5 days, cells were trypsinized and counted electronically using a Coulter counter. Statistical analysis was performed using unpaired Student's t-test. Implant discs coated with hydron/sucralfate/bFGF had significantly increased endothelial cell proliferation compared to discs coated with hydron alone or hydron/sucralfate (p < 0.05). There was no significant difference in the degree of enhanced proliferation between the HA and PP implants treated with hydron/sucralfate/bFGF (p > 0.05). Minimal proliferation occurred around discs treated with hydron alone or hydron/sucralfate. Coating both HA and PP orbital implants with the sustained-release form of sucralfate/bFGF promoted endothelial cell proliferation in vitro. The enhanced proliferation with hydron/sucralfate/bFGF warrants further exploration in an in vivo model.

Animals↗
PubMed2003

Melting after keratoprosthesis implantation: the effects of medroxyprogesterone.

PURPOSE: This study was conducted to evaluate the effect of topical medroxyprogesterone (MPG) following KPro implantation in human subjects in whom donor tissue grafts had been contraindicated by high risk of failure. METHODS: Outcomes of implantation of the Chirila KPro, now known as AlphaCor, were reviewed with respect to postoperative MPG therapy. Ten of 45 (22%) patients had received MPG for a period of 12 months, while 35/45 (78%) had not. MPG treatment was halted because the drug is not approved as an adjunctive treatment of KPro patients. The main outcome measures were the incidence and timing of corneal stromal melting and visual acuity. RESULTS: Of those untreated with MPG, 34% developed a melt (mean follow-up 9.7 months), whereas of those who received MPG, 60% developed a melt (mean follow-up 28.4 months). However, mean time to melt onset for untreated cases was 8.8 months, whereas mean time to melt onset for treated cases was 23.2 months. There is a statistically significant association between time to melt onset, where melts occurred, and MPG therapy (chi2 = 0.001). In both groups, melts were strongly associated with a history of ocular HSV, which represented 17.1% of untreated and 20% of treated cases and is now considered a contraindication for AlphaCor. Preoperative visual acuities were in the range Perception Light (PL)-Count Fingers (CF) in all cases, whereas mean best postoperative best corrected visual acuity was 20/200 (range PL-20/30) in untreated cases and was 20/120 [range Hand Movements (HM)-20/30)] in MPG-treated cases. CONCLUSIONS: Although MPG may not influence the underlying incidence of melt-related complications, which are likely to be associated with other risk factors especially HSV, it may have a protective effect with regard to melt onset and severity. Controlled studies would assist evaluation of its use in this indication.

Administration, Topical↗
PubMed1979

Achilles tendon repair with the plantaris tendon compared with repair using polyglycol threads.

Therapeutic results in 56 surgically treated patients with rupture of the Achilles tendon are presented. Results with repair using plantaris tendon and by suture of polyglycol threads are compared in 41 patients in a long-term followup study. Although 54 patients returned to their pre-accident physical activity, in all cases residual phenomena like calf atrophy, thickening of tendon, and tendon excursion were analyzed. The use of synthetic absorbable threads shortens the convalescence period. Covering the repair site with the fanned plantaris tendon seems to help to avoid painful adhesions with the skin.

Achilles Tendon↗
PubMed1980

The effect of Hydron burn wound dressing on burned rat and rabbit ear wound healing.

The effect of Hydron burn wound dressing was evaluated using a standard Walker burned rat model (N = 156) and a rabbit ear wound model (N = 34). In both studies Hydron was administered only once in one group and changed twice weekly in another. Animals were predesignated as controls and for pathologic examination. Gross observations, including photographic documentation, and the pathologic analyses revealed no gross purulence or sepsis. No deaths occurred in the rabbit study. Of the 156 animals in the rat study only two died; a culture of the wounds revealed no sepsis. Statistical analyses revealed that in the rat study the once only application was significantly better at 7 days postburn than the twice weekly treatment and control groups. No significant differences among the treatment and control groups used in the rabbit study were revealed. The application of Hydron burn wound dressing did not adversely affect the wound healing.

Animals↗
PubMed1978

Oxygen flux into the human cornea when covered by a soft contact lens.

Corneal thickness was measured in human subjects who wore gel lenses that varied only in center thickness. The amount of corneal swelling that developed was a function of center lens thickness. Based on these data and the results of a previous study, the minimum oxygen tension under the lens necessary to maintain normal corneal hydration was determined to be 10 mm Hg. The critical oxygen flux into the cornea at this oxygen tension is 2 microliter/cm2 x hr. Gel-lens center thickness and oxygen permeability can be altered to increase the oxygen tension at the tear/lens interface and resultant oxygen flux into the cornea by increasing the oxygen transmissibility of the lens.

Adult↗
PubMed1984

Effect of in vivo and in vitro surface protein deposits on the oxygen permeability of polyhydroxyethylmethacrylate gel contact lenses.

The effect of surface protein deposits on the oxygen permeability of polyhydroxyethylmethacrylate ( polyHEMA ) gel contact lenses was studied using: (1) previously worn lenses with protein deposits accumulated in vivo, and (2) new lenses with protein deposited in vitro. The oxygen permeability (Dk) of the protein-deposited in vivo lenses was determined before and after cleaning, and that of the new lenses before and after in vitro protein deposition. For both groups of lenses, the oxygen permeability did not change significantly after either cleaning (in vivo lenses) or protein deposition (in vitro lenses). It is concluded that surface protein deposits on polyHEMA lenses do not alter the oxygen permeability of the lenses.

Contact Lenses, Hydrophilic↗
PubMed1998

Modulation of bacterial adhesion to hydrogel contact lenses by albumin.

PURPOSE: The purpose of this investigation was to measure the abilities of Pseudomonas aeruginosa and Staphylococcus epidermidis strains to adhere to two hydrogel lens materials and measure the effect of a protein-coated surface on the number of adhered bacteria. METHODS: Proteins absorbed to contact lenses during sleep were extracted, subjected to sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS-PAGE), and probed for the presence of albumin. Bacterial adhesion was measured by counting bacteria adherent to contact lenses coated in vitro in increasing concentrations of albumin, examining the ability of albumin in solution to prevent adhesion to albumin-coated lenses, and examining the topography of bacterial adhesion by electron microscopy. RESULTS: Albumin adsorbed to lenses during overnight wear. In vitro studies demonstrated that Polymacon lenses adsorbed more albumin than Etafilcon A lenses. In general, the numbers of adherent bacteria increased with increasing concentration of albumin. Bacteria adhered in higher numbers to Polymacon lenses than Etafilcon A (p < 0.05). P. aeruginosa showed an increased adhesion as the amount of albumin on Etafilcon A lenses increased. There was a decrease in numbers of bacteria adhering per milligram of albumin as the level of albumin increased on Polymacon lenses. Cells tended to adhere to "deposits" on albumin-coated lenses. DISCUSSION: Albumin adsorbed onto the surface of contact lenses modulated the ability of P. aeruginosa and S. epidermidis to adhere. P. aeruginosa is commonly associated with contact lens-associated microbial keratitis, where bacterial adhesion to contact lenses is believed to be an important first step in the pathogenesis of the disease.

Adsorption↗
PubMed1998

Antimicrobial efficiency of hydrogel contact lens soaking solutions marketed in Spain.

The antimicrobial efficiency of 20 commercially available solutions for soaking and rinsing soft contact lenses was studied in relation to 5 bacteria (Escherichia coli, Staphylococcus epidermidis, Pseudomonas aeruginosa, Bacillus subtilis, and Serratia marcescens) and 1 fungus (Candida albicans). Each product was separately inoculated with each of six microorganisms, and samples of the inoculated contact lens solutions were taken at predetermined times, placed in a recovery medium, and incubated. Where there was growth, the colonies were counted. There were differences in performance even between solutions labeled as having the same antimicrobial content. One of the solutions marketed in Spain to soak hydrogel contact lenses failed to inactivate all six test strains.

Bacteria↗
PubMed1990

Evaluation of HTR polymer as a craniomaxillofacial graft material.

An experimental animal study was undertaken to evaluate the potential use of HTR polymer as a craniomaxillofacial reconstructive material. Its properties of marked hydrophilicity, a negative surface charge, and extensive porosity combined with a calcium graft coating suggested favorable osteoconductive properties. Four sites of the rabbit craniomaxillofacial skeleton were evaluated by placement of both inlay and onlay implants. Postoperative assessment at 60, 120, and 240 days consisted of histologic evaluation by tetrachrome staining of calcified sections. At 60 days, extensive osseous ingrowth into the inlay implants had occurred extending up to 2000 microns. The onlay implants, however, exhibited more limited ingrowth extending only 100 to 200 microns into the material. Over the ensuing 120- and 240-day postoperative periods, the average depth of bony ingrowth did not progress in either the inlay or onlay specimens over that observed at 60 days. Differences also were noted between the inlayed skeletal sites, with increased marrow at the recipient site resulting in increased bony ingrowth. The material appears to be biocompatible, with no evidence of infection, inflammatory reaction, or bone resorption observed around any of the implants. The implants exhibited a significant osteoconductive capability that was most manifest when implants were exposed to bleeding cortical/marrow surfaces as inlay grafts.

Analysis of Variance↗
PubMed1995

Miragel versus silastic used as episcleral implants in rabbits. An experimental and histopathologic comparative study.

PURPOSE: Tissue reactions to two different biomaterials implanted on the sclera of rabbit eyes, a silicone implant (Silastic; Dow Corning) and a hydrogel (Miragel; Mira Inc.), were evaluated. METHODS: Both materials were implanted on the scleral surface under the superior rectus to obtain a focal scleral buckling. Histopathologic examination of the 32 eyes was performed with transmission electron microscopy 5 to 8 months after implantation. RESULTS: During the follow-up period, 6 silicone implants were extruded, compared with only one hydrogel implant. Histopathologically, both types of implants were surrounded by a newly formed fibrous capsule. Only the hydrogel implant gave rise to a granulomatous foreign body reaction against its own fragments, however. CONCLUSION: The main difference between the two types of material was a superficial fragmentation of the hydrogel implants. The reason for this fragmentation is unknown. To our knowledge, this is the first reported case of foreign body giant cell granuloma that developed against a hydrogel implant.

Animals↗
PubMed2003

Late swelling and removal of Miragel buckles: a comparison with silicone indentations.

BACKGROUND: To describe the indications for removal of Miragel episcleral buckles and to compare them with removed silicone sponges and solid silicone indentations. METHODS: Retrospective analysis of the charts of patients successfully treated for retinal detachment in whom the episcleral buckle was removed after surgery, with a minimal follow-up of 6 months. RESULTS: In a series of 90 eyes of 90 patients, including 38 cases of Miragel elements, 25 cases of solid silicone, and 27 cases of silicone sponge removal, the duration of indentation before removal was significantly longer with Miragel (91.9 months) than with solid silicone (10.6 months) and silicone sponges (18.6 months). In eyes treated with Miragel elements, swelling of the material with progressive limitation of ocular motility and protrusion of the buckle beneath the eyelids indicated its removal in 34 (89.5%) eyes. Infection of the buckle and erosion of the conjunctiva with an exposed indentation were significantly more common with silicone buckles. Overall, scleral perforation occurred in four (4.4%) eyes, and retinal redetachment occurred in eight (8.8%) eyes. CONCLUSION: Late swelling of Miragel buckling elements represents a common indication for buckle removal, significantly different from silicone indentations.

Adult↗
PubMed1994

A comparison of dentoalveolar and venous blood.

Dentoalveolar blood from extraction sites immediately after surgery and venous blood from 28 adult patients was compared for quantitative, qualitative, chemical, and cellular differences. The absence of stem cells, osteoblasts, and osteoclasts from dentoalveolar blood suggests a very low osteogenic potential, no more than that of venous blood. This finding contradicts information supplied by the manufacturer of a microporous, polymeric, composite graft material recommended for use with placement of implants in immediate extraction sites and as onlay grafts to treat ailing implants. The manufacturer's directions call for mixing the alloplast with bleeding marrow harvested from holes drilled in the mandibular symphysis or from a curetted dental socket immediately after a dental extraction in order to stimulate immature marrow cells to form osteoblasts.

Adult↗
PubMed1998

Five-year 224-patient prospective histological study of clinical applications using a synthetic bone alloplast.

Clinical and histologic evaluations of a synthetic bone were performed in 224 patients in a well monitored environment. This material (Bioplant HTR, Bioplant Inc., South Norwalk, CT) was used to obliterate cysts, treat periodontal defects, correct jawbone contours and deficiencies, and gain sufficient support for the placement of dental implants in maxillary subantral augmentation. Implants were positioned either at the time of the synthetic bone graft or after the new supporting tissue was formed. Evidence of new bone formation between the synthetic granules and host tissue was observed during histological examinations. After the material was placed, tissue that could strengthen and augment the inferior wall of the maxillary sinus formed in 3 months. This was observed both clinically and radiographically. After 8 to 12 months, this tissue provided sufficient hard tissue support for the placement of dental implants. This clinical study reconfirmed the applicability of a synthetic bone for bone replacement and augmentation in oral and maxillofacial surgery. No complications caused by infection, inflammation, or rejection of the implanted graft material were observed.

Adult↗