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Biomedical subjects

B S Sires

Publications and source records attributed to B S Sires.

At least 19 recordsLinked to original sources
PubMed2001

The color difference in orbital fat.

OBJECTIVE: To identify and quantify carotenoids found in white and yellow orbital fat. METHODS: Specimens of nasal (white) and preaponeurotic (yellow) orbital fat were obtained from patients during upper eyelid blepharoplasty. Carotenoids and retinoids were extracted and subjected to spectral and high-performance liquid chromatography analyses. RESULTS: The chromophore content of extracts from unsaponified fat, as measured by absorbance at 425 nm per gram of fat, was 2- to 4-fold higher in preaponeurotic fat than in nasal fat. High-performance liquid chromatography analysis from enzymatically digested fat revealed large amounts of lutein, beta-carotene, and retinol and small amounts of other unidentified carotenoids. The amount of beta-carotene and lutein in preaponeurotic fat was approximately 4-fold higher than in nasal fat. CONCLUSIONS: The higher carotenoid content of preaponeurotic fat might cause it to be more yellow than other orbital fat, and lutein and beta-carotene might be selectively absorbed from plasma by preaponeurotic fat. CLINICAL RELEVANCE: The results provide baseline information for studies of the physiological features of orbital fat in normal and diseased conditions.

Adipose Tissue↗
PubMed2001

Systemic corticosteroid use in orbital lymphangioma.

PURPOSE: To describe the clinical results of systemic corticosteroid use in a series of patients with orbital lymphangioma. METHODS: Four patients (two adults and two children) were treated with corticosteroids using intravenous, oral, or both routes for 2 days to a month. Corticosteroids were used with and without other therapies for symptomatic exacerbations. RESULTS: The adults showed more improvement with pain than with swelling, whereas the children had improvement with both the signs and symptoms. There were no complications in any patient. CONCLUSIONS: Systemic corticosteroids are a useful therapeutic option for patients with orbital lymphangioma and can be used as an adjuvant treatment to surgery and other modalities. Resolution of symptoms with corticosteroids was expedited compared with the natural history of the disease in the patients studied.

Administration, Oral↗
PubMed2000

Osteogenesis in a human hydroxyapatite orbital implant 5.5 years after implantation.

PURPOSE: We report the histological findings of a hydroxyapatite orbital implant 5.5 years after implantation. METHODS: The hydroxyapatite orbital implant was excised from the left orbit of a 17-year-old female, and it was decalcified and processed for routine light microscopic evaluation. RESULTS: The implant showed complete fibrovascularization with nearly complete osteogenesis with hematopoiesis. CONCLUSION: Bone may biointegrate throughout the pores of hydroxyapatite orbital implants.

Adolescent↗
PubMed2000

Effect of brief exposure to mitomycin C on cultured human nasal mucosa fibroblasts.

PURPOSE: To observe the effect of mitomycin C (MMC) on cultured human nasal mucosa fibroblasts. METHODS: Cultured human nasal mucosa fibroblasts were exposed to MMC (0.1-0.4 mg/ml) for 1 to 5 minutes. The viability of the fibroblasts was determined by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assay; DNA fragmentation (apoptosis) by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL); apoptotic percentage by flow cytometry; and morphology by light microscopy. RESULTS: A portion of the fibroblasts survived the mitomycin treatment and showed evidence of regrowth within 2 to 3 days. These cells reached confluence in 5 to 7 days. The inhibition rates by MTT assay of 0.4 mg/ml MMC for 5-minute exposures was 31.3%. Dose-response effect was noted with the lower concentrations and shorter exposure times where the inhibition rates were lower (but not significantly so). DNA fragmentation was observed in fibroblasts 24 hours after MMC exposure (0.4 mg/ml) for 5 minutes compared with normal control. The apoptotic rate of fibroblasts treated by 0.4 mg/ml MMC was significantly higher than the control (p < 0.05). CONCLUSIONS: Short MMC exposure times have a variable cytotoxic effect and inhibit proliferation of cultured nasal mucosa fibroblasts. MMC also can induce apoptosis with a 5-minute exposure time. Therefore, it is possible that MMC has a complex effect in dacryocystorhinostomy.

Alkylating Agents↗
PubMed1999

Congenital horizontal tarsal kink: clinical characteristics from a large series.

PURPOSE: To describe the clinical characteristics of congenital horizontal tarsal kink. METHODS: Retrospective clinical series derived from a literature review and mail survey. Characteristics included sex, race, association with systemic diseases, interval between birth and diagnosis, laterality, presence of corneal ulcer and causative infectious agent, treatment, and visual outcome. RESULTS: Twenty-five cases were reviewed. The typical patient is a white male diagnosed at 7.2 weeks of age. Right-sided and bilateral cases were most common. Ulcers were present in 12/24 patients; most were culture negative. Various methods of surgical repair were successful. Visual outcomes, in general, were favorable although amblyopia developed in 4/15 patients. CONCLUSIONS: Congenital horizontal tarsal kink is rare and its cause is unknown. A poor visual outcome usually results from a corneal ulcer scar and a delay in diagnosis. Amblyopia not related to corneal opacification can also occur.

Entropion↗
PubMed1999

A tarsal strip-periosteal flap technique for lateral canthal fixation.

Lateral canthal fixation is widely used. This article sought to determine if a periosteal flap used routinely in conjunction with a tarsal strip provides lasting lateral canthal fixation. This consecutive clinical series from two ambulatory surgery centers followed 79 patients who underwent 141 lateral canthal fixation procedures. Outcome was measured by the position of the lateral canthus. Correct positioning of the lateral canthus was achieved in 78 of 79 patients representing 139 of 141 procedures (98%). The failed case was a patient with floppy eyelid syndrome in whom the sutures tore through the tarsal strips. The tarsal strip-periosteal flap technique is a successful, technically direct method of lateral canthal fixation. It is promoted as an enhancement of the tarsal strip technique, and is especially helpful in patients with prominent eyes.

Aged↗
PubMed1998

Postimplantation density changes in coralline hydroxyapatite orbital implants.

The purpose of our study was to determine serial mineral density changes in coralline hydroxyapatite orbital implants after implantation into the human socket. Prospective analysis by quantitative computed tomography determined the mineral density of hydroxyapatite orbital implants in five patients before and at two time intervals after implantation. Mineral density of the spheres increased an average of 135% after implantation (3-8 months) from preoperative measurements. The density continued to rise an average of 5% (range, -9%-16%) at the second postoperative period (22-39 months). Average follow-up was 30 months. The increased density in the nonevisceration patients was noted in the regions of the scleral windows and the exposed posterior implant where the cornea had been removed from the scleral wrap. The mineral density of hydroxyapatite spheres markedly increases after implantation. Approximately 2 to 3 years later, the densities continue to increase slightly in enucleation and secondary implant cases. An evisceration implant was the only implant to lose density. This study shows no decrease in the mineral density of orbital coralline hydroxyapatite enucleation implants, suggesting a lack of implant mineral resorption.

Adult↗
PubMed1998

Characterization of human orbital fat and connective tissue.

This study was designed to evaluate the characteristics of human orbital fat and connective tissue. Two exenteration specimens were studied by light microscopy with special stains. Four distinct regions were identified on the basis of their connective tissue septa, which contained blood vessels and were composed of elastin and collagen types I, III, and IV. Transmission electron microscopy was performed on the opposite orbits. The fibroblasts and adipocytes appeared metabolically inactive and showed no regional differences. The fat was phase extracted from the connective tissue and subjected to biochemical analysis. No regional differences were found in the content of fatty acids and protein. The fatty acids included palmitic acid (22-24.6%), oleic acid (45-51.5%), and linoleic acid (15-18.6%). Despite demarcation of the orbital fat into distinct regions by the connective tissue septa, ultrastructural and biochemical analysis revealed no regional variations in the fat. The diagnostic and therapeutic implications of these findings are discussed.

Adipose Tissue↗
PubMed1998

Management of displaced lateral orbital wall fractures associated with visual and ocular motility disturbances.

Impacted fractures of the lateral orbital wall are a type of orbital blow-in fracture that may be accompanied by decreased visual acuity and ocular motility limitations. Eleven patients who suffered this injury triad were retrospectively reviewed to determine the nature of the ophthalmologic injuries and the effect of fracture reduction on recovery of ophthalmologic functions. Two patients with decreased visual acuity owing to trauma to the globe recovered to subjective pretrauma levels following surgery. Nine patients were thought to have a traumatic optic neuropathy with varying degrees of visual loss. Patients with an injury to the intraorbital portion of the optic nerve and a presurgical visual acuity of 20/400 or better recovered to subjective pretrauma levels. Those with visual acuity of less than 20/400 or an injury to the intracanalicular portion of the nerve had responses ranging from no improvement to objective improvement with large field defects. Ocular motility improved in all patients, many in the immediate postsurgical period consistent with removal of a mechanical restriction. No patients had worsening of ophthalmologic deficits as a result of manipulation of fracture fragments. Our experience suggests that early surgical intervention facilitates recovery of vision and eye movement. The traumatic optic neuropathy that accompanies this fracture is distinct from the indirect type of optic nerve injury that may respond to steroids, and the ophthalmoplegia is distinct from the usual traumatic superior orbital fissure syndrome that resolves spontaneously. An understanding of the impacted lateral orbital wall fracture and its ophthalmologic implications is essential for any surgeon who desires to manage craniomaxillofacial injuries.

Adolescent↗
PubMed1998

Association between orbital fracture location and ocular injury: a retrospective study.

BACKGROUND: Orbital fractures are frequently accompanied by ocular injury. Any findings that provide information for diagnosing a concurrent ocular injury should improve patient care. A greater incidence of severe ocular injury with certain fracture types was hypothesized, based on orbital wall thickness. METHODS: A retrospective review of 87 consecutive patients (107 fractured orbits) was performed by the Ophthalmology Department of an urban Level 1 trauma center. RESULTS AND CONCLUSIONS: Severe injuries were associated with orbital apex fractures (p = 0.00001), with lateral wall fractures (p < 0.04), and with Le Fort Type III fractures (p < 0.02). Moderate injuries were associated with isolated orbital floor fractures (p < 0.01). Apex, lateral wall, and Le Fort Type III fractures have a greater association with severe ocular injuries than other fracture types.

Accidents, Traffic↗
PubMed1998

Optic nerve size in traumatic optic neuropathy.

The assessment of traumatic optic neuropathy in a neurologically impaired patient is difficult, and the size of the optic nerve has been suggested as a potential adjunct in differential diagnosis. This controlled retrospective study was designed to evaluate the size of the optic nerve involved in traumatic optic neuropathy when compared to the optic nerve in the noninjured eye. Maxillofacial computerized tomographs of 22 patients were examined; intraorbital optic nerve diameter was measured on injured and noninjured sides, with the examiner unaware of the side of injury. No statistically significant difference in size was found between the traumatized optic nerves and those that remained intact. The authors have concluded that the size of the optic nerve is not a reliable predicator of the presence or absence of traumatic optic neuropathy when measured with computerized tomograph scans.

Confidence Intervals↗
PubMed1997

An anatomical basis for primary acquired nasolacrimal duct obstruction.

OBJECTIVE: To measure any sex size differences in the bony nasolacrimal drainage systems in a normal, age-matched population. METHODS: A retrospective study of axial cut maxillofacial computed tomographic scans was conducted. Three levels of the bony nasolacrimal duct (NLD) system on the right and left sides were measured along the anteroposterior diameter. The data were analyzed using 2-tail t test, analysis of variance, and linear regression methods. RESULTS: Scans from 71 adult patients (36 men and 35 women) were reviewed. Women were found to have a smaller bony diameter at the level of the lower fossa (P = .01) and the middle NLD (P = .06) compared with those of men. The adult inferior bony fossa increased in size with age in both men and women, while the middle NLD increased in size in men only. No significant size difference was found between the right and left side at any level. CONCLUSIONS: Size differences are found in measurements of bony nasolacrimal excretory systems in men vs women. Women have significantly smaller dimensions in the lower nasolacrimal fossa and the middle NLD. The anteroposterior dimension of the bony nasolacrimal canal at the fossa level enlarged in both sexes, with age co-inciding with osteoporotic changes throughout the body. These quantitative anatomical observations provide a contributory factor to explain the increased prevalence of primary acquired NLD obstruction in women.

Adult↗