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Biomedical subjects

A Amir

Publications and source records attributed to A Amir.

At least 19 recordsLinked to original sources

Effect of facial pressure garments for burn injury in adult patients after orthodontic treatment.

Pressure garments are commonly used to prevent and control hypertrophic scar tissue. Complications are unusual, though in children with facial burns, pressure garments may lead to skeletal and dental deformities. Studies in adolescents and adults are sparse. We describe a 24-year-old woman who sustained facial burns. Prior to injury, the patient had undergone premolar extraction in preparation for orthodontic treatment. Her post-burn care consisted of application of a Jobst pressure garment. After 2 months treatment, severe deformation of the dental-alveolar structure was observed. This reports suggests that adults after dental extraction are at a high risk of dental-alveolar deformities from pressure garments and might benefit from the use of occlusal wafers.

Adult↗

Characterization of acute and delayed ocular lesions induced by sulfur mustard in rabbits.

PURPOSE: To establish an experimental model for sulfur mustard-induced acute and delayed ocular lesions in rabbits. METHODS: Rabbit eyes were exposed to sulfur mustard (HD) vapor (370, 420 microg/l) for a period of two minutes. A three months follow-up study was carried out, based on the evaluation of clinical, biochemical and histological parameters. RESULTS: HD exposure initiated typical clinical symptoms within 2-6 hrs, characterized by eye closure, eyelid swelling, conjunctival hyperemia, corneal erosions and inflammation. The clinical signs were significantly dose-dependent and reached a peak at 24--72 hrs post exposure. Biochemical evaluation of the aqueous humor exhibited an inflammatory reaction and oxidative stress at 4 hrs after exposure, subsiding at 28 hrs after exposure. Histological examination of corneas at 48 hrs revealed epithelial denudation and marked stromal edema, accompanied by cellular infiltration. Epithelial regeneration started after 72 hrs, and recovery was almost completed within 1--2 weeks, depending on the HD dose. A second phase of pathological processes started as early as two weeks post exposure and was characterized by corneal edema, opacity, recurrent erosions and neovascularization. The delayed injuries were found in 25 and 40% of the eyes respectively, and when appearing, were more severe than the initial ones. CONCLUSIONS: The development of HD-induced ocular lesions in rabbits is similar to the lesions described in human casualties. Quantitative analysis of the various clinical parameters emphasizes the contribution of each tissue to the overall toxic picture. Our experimental model is useful for studying the pathological mechanisms of HD-ocular lesions, and may serve for testing potential therapies.

Acute Disease↗

The digital pulp as a presenting site of metastatic esophageal carcinoma.

An unusual skin lesion may be a primary skin cancer or a sign of internal malignancy. Metastatic lesions to the hand are rare. The authors describe a patient who presented with a nodule of the digital pulp. Workup, including X-ray films and biopsy, revealed a metastatic squamous cell carcinoma invading the distal phalanx. The primary site of the tumor was the esophagus. To the best of their knowledge, this is the second case described in the literature of a metastatic carcinoma of the esophagus presenting as a lesion of the digital pulp.

Aged↗

Walk-through injuries: glass door facial injuries.

During 1998, 13 patients were treated in the Tel-Aviv Sourasky Medical Center for complex facial soft-tissue injuries caused by passing through large, clear glass doors. All epidemiological details were gathered and analyzed. Of 1,100 soft-tissue facial injury admissions in 1 year, 13 patients had a substantial soft-tissue facial injury after passing through a glass barrier. Nine were injured during leisure time activity, five in a shopping mall, and four in their residence. Interestingly, the authors found a common pattern of facial injuries in all patients. It consisted of large, irregular, composite skin and soft-tissue flaps as well as large, tom, irregular skin lacerations. The nose was injured predominantly, and the injury was particularly complex. Their recommended management of these injuries is a thorough and careful evaluation of flap viability. Surgical management of avulsed, viable flaps includes margin debridement and repositioning. If the flap is narrow enough, it can be debrided and the margins adapted primarily. If viability of part of the flap is in doubt, that part should be debrided and used as a composite graft. When this graft dies, a full-thickness graft is taken from another facial site. The cosmesis of such a graft is better than using the debrided, thin segment as a skin graft that is too thin. The authors emphasize that there is a need to encourage authorities to reinforce regulations relating to injury prevention from architectural glass. The first is to use special glazing, either tempered glass, laminated glass, or both. The other method of improving safety is by indicating glass using decorations or warning stickers, or by making it partly translucent. Unless these regulations are obeyed, fatal or complex trauma may occur.

Adult↗

Treatment of skin injuries induced by sulfur mustard with calmodulin antagonists, using the pig model.

Sulfur mustard (HD) is a potent cutaneous vesicant that penetrates rapidly through the skin, causing prolonged injuries and leading to severe incapacitation. Although there has been long and intensive efforts to find a treatment for HD skin lesions, no effective treatment is available for HD-induced skin injuries. Recently, ointments containing calmodulin antagonists were found to be effective in preventing skin injuries induced by HD in hairless mice. The present study was designed to investigate the beneficial effects of topical treatments with calmodulin antagonists against HD skin lesions in the pig model. The pig is used as a preferred animal model for human skin in many studies, including vesicants. Neat HD, either in liquid form (0.2-1 microl droplets) or as vapour, was applied to the back skin of female pigs (a cross Large White & Landrace, 10-12 kg) for various exposure durations. Evaluation was based on quantitative analysis of the degree of erythema and area of the lesions, as well as histological evaluation. Calmodulin antagonists (10% pentamide, 1% trifluoperazine, 2% thioridazine) and anaesthetics (20% lidocaine and 3% benoxinate) were dissolved in pluronic F-127 base according to Kim et al. (Eur. J. Pharmacol. 1996; 313: 107-114) or in saline, and were applied either topically as ointments or by intradermal injection, as early as 5 min post-exposure (twice a day for at least 3 days). The results demonstrated that topically applied pluronic base ointments containing lidocaine or pentamide produce beneficial effects when applied immediately after short-term HD exposure to pig skin.

Administration, Topical↗

Beneficial effects of topical anti-inflammatory drugs against sulfur mustard-induced ocular lesions in rabbits.

Ocular injuries following sulfur mustard (HD) exposure are characterized by an inflammatory response, observed as eyelid swelling, conjunctivitis, corneal oedema and cellular infiltration starting 1-4 h after exposure, depending on dose. These effects heal partially during the first 1-2 weeks after exposure, with the later appearance of neovascularization, recurrent erosions and recurrent oedema of the cornea (delayed response). We have shown previously that topically applied steroid treatment, administered after HD exposure, attenuated the extent of neovascularization, one of the characteristics of delayed ocular pathology in rabbits. The present study was designed to characterize further the initial inflammatory response and to elucidate the role of anti-inflammatory (AI) drugs as a potential therapy. Rabbit eyes were exposed to HD vapour (390 microg l(-1) for 2 min) and were treated with a topical commercial ophthalmic solution of dexamethasone or diclofenac, starting 1 h post-exposure (four times a day). Inflammation was evaluated by clinical observations, biochemical analysis of aqueous humour and by histology. Sulfur mustard exposure initiated typical clinical ocular symptoms within 4-6 h after exposure. Biochemical analysis of aqueous humour showed that protein content and prostaglandin E (PGE) increased significantly at 6 h and were still high 48 h after HD exposure. Light microscopy evaluation revealed severe damage to the cornea, characterized by epithelial denudation, oedema and cellular infiltration (mostly eosinophiles) in the stroma. Both treatments were effective in alleviating the clinical symptoms and in preventing the HD-induced increase in protein and PGE in the anterior chamber, as well as the cellular infiltration, in the corneal stroma. However, the AI treatments had no therapeutic effect on corneal erosions, and a short delay in epithelial regeneration was noted. It is concluded that AI drugs are potential candidates for the treatment of ocular lesions following HD exposure.

Animals↗

Sulfur mustard toxicity in macrophages: effect of dexamethasone.

Cells from the murine macrophage-like cell line J774A.1 (J774) and cultures of primary alveolar macrophages (PAM) obtained from guinea pigs were exposed to sulfur mustard (HD, 50-200 microM) and treated with dexamethasone (2.5 microM) 10 min after HD exposure. Cell cultures were studied at 3 and 24 h after exposure by the cleavage of Thiazolyl blue reaction (MTT) reaction and crystal violet staining (viability assays), by morphological observation and by [3H]thymidine incorporation. Exposure of J774 cells to HD caused a dose-dependent decrease in viability that was evident at 24 h. Although no significant change in viability was observed at 3-4 h after HD exposure, a dose-dependent decrease in [3H]thymidine incorporation was observed. Treatment with dexamethasone caused a dose-dependent decrease in viability. However, the combined exposure to HD and dexamethasone had a synergistic effect on the decrease of cell viability. This synergistic effect is not due to a change in DNA synthesis rate because [3H]thymidine incorporation was not affected by dexamethasone. In PAM cultures, HD caused some 'activating' effect on [3H]thymidine incorporation and an increase in cell number at the lower dose (100 microM) but this was less at 200 microM. Both effects were reduced by dexamethasone treatment. We conclude that macrophages derived from different sources exhibit a different responsiveness to immunomodulators (HD and dexamethasone) and that dexamethasone can reduce the 'inflammatory' effect of HD in PAM.

Animals↗

Palladium(II) complexes of NS donor ligandsderived from S-methyl-dithiocarbazate, S-benzyldithiocarbazateand thiosemicarbazide as antiamoebic agents.

Synthesis of palladium(II) complexes of the type [PdLCl(2)] (where L = Schiff bases derived from 2-acetylpyridine and S-methyldithiocarbazate, S-benzyldithiocarbazate or thiosemicarbazide) have been isolated by the reaction of [Pd(DMSO)(2)C1(2)] and respective ligands. The complexes have been characterized by elemental analyses, IR, 1H-NMR, electronic spectra and thermogravimetric analysis. It is concluded that the thionic sulphur and the azomethine nitrogen atoms of the ligands are bonded to the metal ion. Assessment of antiamoebic activity against Entamoeba histolytica (strain HK-9) was done by using a microdilution method. [Pd(2-Acpy-SMDT)C1(2)] and Pd(2-Acpy-SBDT)C1(2)] have shown greater activity, whereas [Pd(2-Acpy-TSC)C1(2)] showed similar activity as metronidazole in vitro.

Amebicides↗

Efficient nonviral transfection of dendritic cells and their use for in vivo immunization.

Immunization with dendritic cells (DCs) transfected with genes encoding tumor-associated antigens (TAAs) is a highly promising approach to cancer immunotherapy. We have developed a system, using complexes of plasmid DNA expression constructs with the cationic peptide CL22, that transfects human monocyte-derived DCs much more efficiently than alternative nonviral agents. After CL22 transfection, DCs expressing antigens stimulated autologous T cells in vitro and elicited primary immune responses in syngeneic mice, in an antigen-specific manner. Injection of CL22-transfected DCs expressing a TAA, but not DCs pulsed with a TAA-derived peptide, protected mice from lethal challenge with tumor cells in an aggressive model of melanoma. The CL22 system is a fast and efficient alternative to viral vectors for engineering DCs for use in immunotherapy and research.

Animals↗

The influence of helium-neon laser irradiation on the viability of skin flaps in the rat.

Low energy helium-neon (He-Ne) laser irradiation has been shown to induce various therapeutic effects. We investigated its effect on the viability of skin flaps in the rat. Thirty rats underwent skin flap elevation and were then divided into three equal groups. Group I (control) was not irradiated. Groups II and III were irradiated for 5 days postoperatively, Group II to the transition zone (between the live and expected necrotic areas) and Group III to the transitional and distal zones; total energy, 2.9 J/cm(2)for each rat. Ten days after the last treatment larger surviving areas were demonstrated macroscopically in Groups II and III (P< 0.01 and 0.001, respectively). Histological examination showed tremendous proliferation of capillaries (P</= 0.05) and fibroblasts in the responsive irradiated areas. In conclusion, postoperative low-energy (2.9 J/cm(2)) He-Ne laser irradiation of the expected ischaemic zone of the rat flap can enlarge the surviving area. Irradiation of the whole expected ischaemic zone seems to be superior to irradiating the transition zone alone.

Animals↗

Congenital Volkmann-Lesser ischemic contracture of the upper limb.

Neonatal vascular compromise to limbs has been associated traditionally with perinatal injury of the brachial plexus, fracture of the clavicle or humerus, or iatrogenic causes. Congenital Volkmann's ischemic contracture is an exceptional etiology of ischemic limb in the newborn. Fewer than 10 cases had been described in the literature. The authors report a newborn presenting at birth with partial bluish discoloration of the right forearm. The clinical picture and laboratory studies lead to the diagnosis of congenital Volkmann-Lesser ischemic contracture.

Arm↗

"Apron" flap and re-creation of the inframammary fold following TRAM flap breast reconstruction.

To the best of our knowledge, the recreation of an inframammary fold after TRAM flap breast reconstruction has not yet been described. This article offers a technique for the creation of an inframammary fold as a secondary procedure. The technique has been performed thus far in two patients with good aesthetic outcomes and no postoperative complications. It may also be suitable for adding bulk to the TRAM flap, especially in bilateral breast reconstruction, and for other minor chest deformities.

Adult↗