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Biomedical subjects

R L Green

Publications and source records attributed to R L Green.

At least 19 recordsLinked to original sources
PubMed2005

Changes in axial length following trabeculectomy and glaucoma drainage device surgery.

AIM: This study examines the changes in axial length (AL) after trabeculectomy and glaucoma drainage device (GDD) surgery and enabled an equation to be derived allowing prediction of AL change after filtering surgery. METHODS: This was a prospective, interventional case series from the Glaucoma Service of the Doheny Eye Institute. PATIENT POPULATION: One eye of 39 patients undergoing trabeculectomy and 22 undergoing Baerveldt tube shunt implantation for uncontrolled glaucoma. INTERVENTION: These patients had AL measurements by non-contact, partial coherence interferometry preoperatively, at 1 week, 1 month, and >3 months after surgery. MAIN OUTCOME MEASURES: Axial length and intraocular pressure were compared at preoperative and postoperative visits. Postoperative intraocular pressure (IOP) was categorised as hypotonous (0-4 mm Hg), low (5-9), normal (10-17), and high (18 or more). RESULTS: There was a statistically significant reduction in IOP after 3 months of -12.8 (SD 1.5) mm Hg following trabeculectomy (p<0.001), and -10.7 (1.9) mm Hg after GDD (p<0.001). There was a statistically significant reduction in AL, which was similar after trabeculectomy and GDD at all time points (p<0.001), of -0.15 (0.03) and -0.21 (0.04) mm (1 week), -0.18 (0.02) and -0.10 (0.02) mm (1 month), and -0.16 (0.03) and -0.15 (0.03) mm (3 months). At 3 months or later the AL reduction was related to postoperative IOP and to the amount of IOP reduction (p<0.05, stepwise multiple regression). 10.2% (4/39) of trabeculectomy patients had hypotony after 3 months, with a mean AL reduction (-0.39 (0.11)) that was statistically significantly lower (p<0.01) than the other trabeculectomy eyes (-0.14 (0.15)). CONCLUSIONS: There is a small but statistically significant decrease in AL after both trabeculectomy and GDD surgery, greater in eyes that are hypotonous after surgery. The authors suggest that AL reduction can be predicted after 3 months by the formula: AL reduction (mm) = -199+0.006 x IOP reduction+0.008 x final IOP.

Aged↗
PubMed2002

Environmental fate of metalaxyl and chlorothalonil applied to a bentgrass putting green under southern California climatic conditions.

Putting greens usually receive high inputs of fertilizers and pesticides to meet the high demand for visual quality and to overcome the stress from close mowing and traffic. In this study, two commonly used fungicides, metalaxyl (methyl N-(methoxyacetyl)-N-(2,6-xylyl)-DL-alaninate) and chlorothalonil (2,4,5,6-tetrachloro-1,3-benzenedicarbonitrile), were evaluated for their partitioning and persistence in a bentgrass (Agrostis palustris Huds) putting green under southern California climatic conditions. The putting green site was constructed according to the US Golf Association (USGA) specifications. Lysimeter assemblies installed at the center of each plot were used to monitor the leachate, flux chambers were used to measure volatilization, clippings were collected to determine the residues on grass, and soil cores were sampled to determine residues in the soil profile. Results showed that cumulative volatilization loss accounted for 0.10 and 0.02%, clipping removal 0.11 and 0.13%, and cumulative leaching 0.71 and 0.002% of the applied metalaxyl and chlorothalonil, respectively. The two fungicides were mainly found in the top 10 cm of the soil profile due to the high organic carbon content in the thatch and mat layers. The dissipation half-life was 1.4 days for metalaxyl and 4.9 days for chlorothalonil on grass, shorter than those found in agricultural fields. This study showed that, under normal turf management practices, the offsite transport of the parent fungicides was minimal. Future research should focus on investigating the fate and mobility of the metabolites of the fungicides.

Adsorption↗
PubMed2001

Metastatic adenocarcinoma with rupture through the Bruch membrane simulating a choroidal melanoma.

PURPOSE: To report a case of adenocarcinoma metastatic to the choroid with rupture through the Bruch membrane, thus, simulating a choroidal melanoma. METHODS: Interventional case report. Evaluation in a university-based clinic, including a complete eye examination, fluorescein angiography, and ultrasonography; oncological evaluation; and eventual enucleation with histopathological study, including immunohistochemical stains. RESULTS: A 62-year-old Hispanic female presented with visual loss, right eye, of short duration because of a choroidal mass with retinal detachment. Ultrasonography showed a dome-shaped lesion with an eccentric collar-button projection and medium internal reflectivity, which suggested a choroidal melanoma. Initial systemic evaluation was negative. Severe pain necessitated enucleation, RE, and histopathology of the choroidal mass demonstrated an adenocarcinoma. Further examination revealed a left, upper lobe, nonsmall cell lung carcinoma. CONCLUSION: Metastatic choroidal tumors may present, although rarely, with collar-button configurations.

Adenocarcinoma↗
PubMed2001

Exudative retinal detachment in relapsing polychondritis : case report and literature review.

OBJECTIVE: To report the atypical ocular symptoms (arterialized conjunctival vessels, exudative retinal detachment) that can be the presenting manifestations of relapsing polychondritis. DESIGN: Observational case report and literature review. METHODS: A complete ocular and systemic evaluation was performed on a patient with relapsing polychondritis and exudative retinal detachment. MAIN OUTCOME MEASURES: Retinal, choroidal, and scleral findings. RESULTS: A 73-year-old man with relapsing polychondritis presented with a unilateral large bullous exudative retinal detachment and marked choroidal and scleral thickening bilaterally. CONCLUSIONS: Ophthalmologists should consider relapsing polychondritis in the differential diagnosis of exudative retinal detachment. A combination of echographic and laboratory findings can assist in the accurate diagnosis of this rare condition.

Aged↗
PubMed2000

Volatility of radiopharmacy-prepared sodium iodide-131 capsules.

OBJECTIVE: The aims of this study were to quantify the extent of volatilization from 131I-NaI therapeutic capsules prepared in a centralized radiopharmacy and to quantify the amount of volatile 131I released from a dispensing vial containing a compounded 131I-NaI therapy capsule. METHODS: Therapy capsules were prepared by injecting 131I oral solution into capsules containing anhydrous dibasic sodium phosphate. Volatilized activity was obtained by filtering air drawn across samples that were placed open on the bottom of a sample holder cup. Volatile 131I was captured by filtering it through 3 triethylenediamine-impregnated carbon cartridge filters, arranged in series. To quantify the amount of volatile 131I released from a dispensing vial during a simulated patient administration, a vial containing a compounded 131I therapy capsule was opened inside a collapsible plastic bag and all the air was drawn across TEDA-impregnated carbon cartridge filters. RESULTS: The 370-MBq (10-mCi) 131I capsules from the first part of the experiment released an average of 0.035% (SD 0.031%) of the capsule activity on the first day, 0.012% (SD 0.002%) on the second day, and 0.012% (SD < 0.001%) for days 3 through 5. The 37-MBq (1-mCi) 131I capsules released an average of 0.058% (SD 0.025%) on the first day, 0.029% (SD 0.009%) on the second day, and 0.020% (SD 0.004%) on the third day. The activity released from the vial during a simulated patient administration was 0.00093% of the 131I capsule activity. CONCLUSION: The amount of 131I, which volatilized daily from the exposed therapy capsules, was a small percentage of the capsule activity. The volatile 131I that would be released during a patient administration was much less than the activity that volatilized from the exposed therapy capsules.

Humans↗
PubMed1999

The caudal infrasylvian surface in dyslexia: novel magnetic resonance imaging-based findings.

OBJECTIVE: To detect anatomic abnormalities of auditory association cortex in dyslexia by measuring the area of the perisylvian region known as the caudal infrasylvian surface(s) (cIS) in dyslexic and control subjects. BACKGROUND: Several quantitative morphometric investigations of cortical areas in dyslexia have focused on the cIS, which encompasses the supratemporal plane and the inferior bank of the posterior ascending ramus of the sylvian fissure. Inconsistencies in the results of these studies may be attributable in part to the use of measurement methods that do not account fully for surface undulations of the cIS. METHODS: The authors used an MRI-based surface reconstruction technique that models the curvature of the cerebral cortex in three dimensions to obtain whole-hemisphere and regional surface area estimates. Measurements were obtained in both hemispheres of eight right-handed male dyslexic subjects and eight right-handed male control subjects. RESULTS: The cIS area of dyslexic subjects was significantly larger than that of control subjects, and this result was not attributable to a difference in whole-hemisphere surface area. Neither the dyslexic nor control subjects showed a left or right asymmetry in this region, although there was a trend toward less variance of the asymmetry scores in dyslexic subjects. CONCLUSIONS: The gross anatomic organization of this region is different in dyslexic subjects, and elucidation of the precise nature of these differences may be aided by surface modeling techniques.

Adult↗
PubMed1999

Search for the trematode Prouterina wescotti in black bears in Oregon.

Forty-six heads of free-ranging black bears (Ursus americanus) collected in May and June of 1995 and 1996 from Oregon (USA) were examined for the trematode Prouterina wescotti and other parasites. Only Sarcocystis sp. was detected in two adult male bears. Prouterina wescotti has been found only once previously in one black bear from Idaho (USA); its normal definitive host remains unknown.

Animals↗
PubMed1998

Uveal lymphoid infiltration. Report of four cases and clinicopathologic review.

PURPOSE: The purpose of the study was to report the clinicopathologic features of four patients with uveal lymphoid infiltration who were diagnosed by a conjunctival biopsy. DESIGN: A case series. PARTICIPANTS: Four patients at four institutions participated. MEASURES: The histopathologic findings of the conjunctival and episcleral biopsy specimens from four patients with the diagnosis of uveal lymphoid infiltration were recorded. The conjunctival specimens were placed in 10% neutral buffered formaldehyde solution or B5 solution and processed routinely for light microscopic examination and immunohistochemical analysis for B cells and T cells and kappa and lambda light chains. The clinical and histopathologic findings were compared with 47 previously reported cases of uveal lymphoid infiltration. RESULTS: Two men and two women (average age = 57 years) presented with diffuse punctate to coalescent yellow uveal infiltrates and epibulbar pink fleshy lesions. Ultrasonography of the lesions showed diffuse choroidal thickening and a lack of choroidal or scleral excavation. The conjunctival biopsy specimens showed diffuse infiltration of the substantia propria with B lymphocytes with variable kappa and lambda restriction. Scattered T lymphocytes also were present. Plasmacytoid cells and a prominent Grenz zone were present. CONCLUSIONS: Patients with solitary or multiple yellow uveal infiltrates should have careful conjunctival evaluation for the presence of pink conjunctival lesions. Biopsy specimens of the conjunctival lesion may establish the diagnosis of uveal lymphoid infiltration.

Adult↗
PubMed1998

Brain size, head size, and intelligence quotient in monozygotic twins.

Many studies of monozygotic (MZ) twins have revealed evidence of genetic influences on intellectual functions and their derangement in certain neurologic and psychiatric diseases afflicting the forebrain. Relatively little is known about genetic influences on the size and shape of the human forebrain and its gross morphologic subdivisions. Using MRI and quantitative image analysis techniques, we examined neuroanatomic similarities in MZ twins and their relationship to head size and intelligence quotient (IQ). ANOVA were carried out using each measure as the dependent variable and genotype, birth order, and sex, separately, as between-subject factors. Pairwise correlations between measures were also computed. We found significant effects of genotype but not birth order for the following neuroanatomic measures: forebrain volume (raw, p < or = 0.0001; normalized by body weight, p = 0.0003); cortical surface area (raw, p = 0.002; normalized, p = 0.001); and callosal area (raw, p < or = 0.0001; normalized by forebrain volume, p = 0.02). We also found significant effects of genotype but not birth order for head circumference (raw, p = 0.0002; normalized, p < or = 0.0001) and full-scale IQ (p = 0.001). There were no significant sex effects except for raw head circumference (p = 0.03). Significant correlations were observed among forebrain volume, cortical surface area, and callosal area and between each brain measure and head circumference. There was no significant correlation between IQ and any brain measure or head circumference. These results indicate that: 1) forebrain volume, cortical surface area, and callosal area are similar in MZ twins; and 2) these brain measures are tightly correlated with one another and with head circumference but not with IQ in young, healthy adults.

Adult↗
PubMed1997

Annular peripheral choroidal detachment simulating aqueous misdirection after glaucoma surgery.

PURPOSE: The purpose of the study was to define a newly recognized complication after glaucoma surgery and to recommend a therapeutic regimen. METHODS: Eighteen patients diagnosed initially as having aqueous misdirection after glaucoma surgery, but who subsequently were found by ultrasonography to have an annular peripheral choroidal detachment that resulted in secondary angle closure glaucoma, were studied. Ten of these patients were treated with topical cycloplegics and corticosteroids, and 8 were treated with drainage of suprachoroidal fluid. Outcomes of these two treatment methods were compared. RESULTS: Annular peripheral choroidal detachment reliably was diagnosed with ultrasonography. Of the variables studied, time elapsed before resolution of the annular peripheral choroidal detachment was noted to be statistically significant (P < 0.00005). Immediate resolution followed drainage of suprachoroidal fluid, whereas a mean of 19.6 days was required for resolution after medical therapy. CONCLUSIONS: Annular peripheral choroidal detachment should be considered in the differential diagnosis of a flat or shallow anterior chamber with normal or high intraocular pressure after glaucoma surgery. The diagnosis of annular peripheral choroidal detachment can be confirmed most reliably by ultrasonography. Medical therapy is as effective as is surgery, although a significantly longer time to resolution is required.

Adult↗
PubMed1996

How lesioning the nucleus praeeminentialis affects electrolocation behavior in the weakly electric fish, Apteronotus leptorhynchus.

The ability to orient to and track moving electrolocation targets was assessed in normal Apteronotus leptorhynchus and in those with unilateral lesions of the nucleus praeeminentialis dorsalis. 1. Each fish was trained to hover between two vertical metal rods and track their movement. Two aspects of this behavior were measured: a) the hovering position of the fish relative to stationary rods; b) the latency between the onset of rod motion and the fish's tracking response. Control fish hovered midway between stationary rods, while lesioned fish hovered closer to the rod ipsilateral to the lesion. Response latency varied negatively with rod diameter in both sets of fish, and lesioned fish exhibited shorter latencies than control fish. While the response latencies of control fish were shortest when their starting position was midway between the rods, lesioned animals latencies were shortest when they hovered closer to the rod ipsilateral to their lesion. 2. Control fish responded to the approach of a single metal ball to either side of the body with nearly equal latencies and fish-to-object distances. After lesioning, response latency increased and fish-to-object distance decreased for approaches to the side ipsilateral to the lesion; opposite changes occurred for contralateral approaches.

Animals↗
PubMed1996

Posterior vitreoschisis. An echographic finding in proliferative diabetic retinopathy.

PURPOSE: To describe the echographic characteristics of splitting the outer posterior cortical vitreous in patients with proliferative diabetic retinopathy and vitreous hemorrhage. METHODS: The authors retrospectively reviewed the echographic findings in 270 patients who were evaluated at the Doheny Eye Institute between January 1983 to December 1989 for proliferative diabetic retinopathy and vitreous hemorrhage. None of the eyes had undergone pars plana vitrectomy before echographic examination. RESULTS: Forty-five patients (17%) had echographic evidence of splitting of the outer posterior vitreous cortex, a finding the authors have termed posterior vitreoschisis. In all patients, differentiation of the posterior vitreoschisis from a true posterior hyaloid detachment was possible, either on the initial or on serial echographic examination, by the separate detachment of the inner wall of the vitreoschisis cavity and the true posterior hyaloid from the retinal surface. The vitreoschisis cavities often were found to contain unclotted blood. In some eyes, the inner wall of the vitreoschisis cavity was adherent to the apex of the most highly elevated area of traction retinal detachment, suggesting that posterior vitreoschisis may itself result in clinically significant vitreoretinal traction, independent of the presence or extent of true posterior hyaloid separation. CONCLUSIONS: The authors' finding suggest that spontaneous splitting of the outer posterior vitreous cortex may occur in patients with proliferative diabetic retinopathy and vitreous hemorrhage, which may mimic a true posterior cortical vitreous detachment on echographic examination. Preoperative recognition of posterior vitreoschisis may be important in the surgical management of these patients.

Adult↗
PubMed1996

Trimethylamine N-oxidation in Turkish women with bacterial vaginosis.

Bacterial vaginosis (BV) is the most common cause of vaginal discharge in women of child-bearing age. A common symptom of this condition is a fishy-smelling vaginal discharge. Trimethylamine (TMA) is the substance which is primarily responsible for this distinctive odour. The ability to metabolize TMA is polymorphically distributed such that the majority of individuals metabolize a large part of the body burden of TMA to the odourless trimethylamine N-oxide (TMAO) which is excreted in urine with a small amount of TMA. However, in certain individuals, N-oxidation of TMA is impaired which results in the excretion of large amounts of TMA in the urine, breath, sweat and vaginal secretions. In the present study the metabolism of TMA to TMAO was determined in women with clinically diagnosed BV, women with fishy-smelling vaginal discharge but with no other evidence of BV and control women with no evidence of fishy-smelling vaginal discharge. An index of TMA N-oxidation was established for all subjects after analysis of a 24 h urine sample for free TMA and total TMA after reduction of TMAO. We show that, irrespective of diagnosis of BV or not, women with fishy-smelling vaginal discharge excrete significantly more free TMA and have a similarly significantly reduced capacity to N-oxidize TMA when compared to healthy control women. Thus, the results of this study suggest that a woman's ability to metabolize TMA to TMAO is an important factor which predisposes to a fishy-smelling vaginal discharge.

Adolescent↗