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Biomedical subjects

R L Abbott

Publications and source records attributed to R L Abbott.

14 recordsLinked to original sources
PubMed1992

Hypotony and corneal edema secondary to patching in normal eyes.

Over the past decade investigators have used patching when studying corneal response to eye lid closure. In these studies, corneal edema was thought to be secondary to hypoxia, and the results were used to predict corneal response to contact lens wear. None of these studies have measured or controlled the intraocular pressure (IOP) during eye patching. Reports in the literature indicate that hypotonous and hypertensive events may induce corneal edema. In order to evaluate the IOP and corresponding corneal changes, measurements were made on subjects with patched eyes. Thirty subjects were unilaterally patched and randomized into tight and light patch groups to maintain complete lid closure for 4 h. Measurements of IOP and corneal thickness (CT) were made at baseline and at hourly intervals. The contralateral eye served as the control for each subject. Our results indicate a significant decrease in IOP and a corresponding increase in CT in the tight patched group as compared to the light patch group, and baseline controls. These results suggest that the corneal edema which results from patching of the eye may be due to hypotony, or a combination of factors affecting corneal function, rather than hypoxia.

Bandages↗
PubMed1992

Microbial changes in the ocular environment with contact lens wear.

A group of 30 subjects, each fit with a single disposable or non-disposable soft contact lens, was further randomized to a daily wear or extended wear schedule to determine the effect of lens wear on the normal conjunctival flora. Cultures of the subjects' inferior cul-de-sacs were taken at baseline before any lens wear and after one week of lens wear. Additionally, each subjects' lens was removed in a sterile manner and cultured at the end of the one week wear period. In all subjects, the fellow eye was used as a control. There were no statistically significant differences with respect to bacterial culture results between experimental and control eyes. Also, there were no significant differences between the pre- and post-lens wear groups. And no significant differences were found when the larger groups were broken down into different wear schedules and lens types and compared. The results of this study suggest that the ocular flora is not markedly changed after one week of contact lens wear. Also raised is the question of whether an altered ocular flora is an etiologic factor in the development of infectious keratitis in contact lens wearers.

Bacteria↗
PubMed1991

Concurrent cisplatin, infusional fluorouracil, and conventionally fractionated radiation therapy in head and neck cancer: dose-limiting mucosal toxicity.

After a preliminary dose-finding study involving 12 patients with advanced or locally recurrent head and neck cancer, 27 patients were treated on a phase II protocol, using fluorouracil 350 mg/m2/d by continuous intravenous (IV) infusion over 5 days, followed on the sixth day by a 2-hour IV infusion of cisplatin 50 mg/m2, administered during the first and fourth weeks of radiation therapy to total doses between 60 and 64 Gy, using 2 Gy daily fractions. Eight of these 27 patients had American Joint Committee on Cancer Staging (AJCC) stage III disease, and 12 had stage IV disease. Four had recurrent disease after surgery. Three-year follow-up is now available. Twenty-one (77.8%) remitted completely following treatment, and 11 remain free of local and regional relapse at 3 years. Four have developed systemic metastases. Following successful salvage treatment in two cases, estimated determinate survival at 3 years is 64%. Acute toxicity was manageable with this regime. Eleven instances of grade 3 Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer (RTOG/EORTC) mucositis were observed, which caused interruptions to radiotherapy in only four cases. No late sequelae have so far been recorded. It is concluded that the protocol described is tolerable but probably did not cause a greater number of locoregional "cures" than would have been expected following conventional radiotherapy alone in this group of patients. The use of infusional fluorouracil with concurrent conventionally fractionated radiation therapy and cisplatin infusion results in mucositis that limits the dose of fluorouracil to levels that are probably subtherapeutic.

Adult↗
PubMed1979

Urinary ferritin protein in subjects with prosthetic heart valves and other disorders.

Twenty-four-hour urine ferritin protein excretion (UFPE) was elevated in the great majority of patients with prosthetic cardiac valves. In this group, there was a positive correlation with the presence of haemosiderin in the urine and with another indirect measure of reduced red-cell survival, namely, serum lactic dehydrogenase. In a number of hospital patients with various disorders, UFPE was also increased. In this latter group, however, there was no constant accompanying haemosiderinuria or elevation of lactic dehydrogenase. The measurement of UFPE can be added to the list of screening tests for intravascular haemolysis, but analysis of the different isoferritins in urine is necessary to fully understand the mechanism of excretion in the different groups.

Anemia, Hemolytic↗
PubMed1979

Determinants of graft clarity in penetrating kerotoplasty.

A total of 240 consecutive penetrating keratoplasties with a minimum six months' follow-up were examined to determine the influence of preoperative prognosis, donor age, death-enucleation time, death-surgery time, and surgical experience on graft clarity. Graft results, classified as clear, nebulous, or edematous, were compared within two prognostic categories in aphakic, combined, and phakic keratoplasty groups. Preoperative prognostic groups and surgical experience appeared to be most important in affecting graft clarity, whereas the donor age, death-enucleation time, and death-surgery time seemed to have little effect.

Age Factors↗
PubMed1979

Clinical specular microscopy and intraocular surgery.

Seventy patients were studied prospectively, using the clinical specular microscope, to compare and evaluate the effects on the corneal endothelium of routine intracapsular cataract extraction (ICCE), ICCE with intraocular lens (IOL) implantation, phacoemulsification, and penetrating keratoplasty. Results showed a 6% cell loss after ICCE, 12% loss after IOL insertion, 14% after phacoemulsification, and 21% loss after penetrating keratoplasty. Both phakic and aphakic grafts had 21% cell loss. Within the aphakic keratoplasty group, there was a 10% cell loss in patients who maintained an intact vitreous face compared with a 26% cell loss in patients who underwent an anterior vitrectomy (P less than .1).

Adult↗
PubMed1979

Superficial punctate keratitis of Thygeson associated with scarring and Salzmann's nodular degeneration.

A 59-year-old woman with superficial punctate keratitis of Thygeson was observed for 14 years. The patient was treated intermittently with topical corticosteroids and artificial tears. Immediate symptomatic relief was followed by multiple recurrences and exacerbations. This case was atypical because of its prolonged clinical course and development of permanent, subepithelial corneal scarring, and elevated lesions resembling Salzmann's nodular degeneration.

Administration, Topical↗
PubMed1979

Necrotizing erysipelas of the eyelids.

A 72-year-old, healthy white woman presented with rapidly advancing necrotizing erysipelas of the upper and lower eyelids. There was no previous history of trauma or skin abrasions. The patient was treated with intravenous methicillin (Staphcillin) for 2 weeks and oral cloxacillin (Tegopen), for 1 week with intensive wound cleaning and debridement. After 3 months of continuous wound care, the patient has healed her wounds by second intention, with a moderate amount of lid contracture. Further surgical correction of the lower lid defect may be necessary.

Aged↗
PubMed1978

Adult acute lymphoblastic leukaemia: a five-year experience.

The case histories of all patients for whom the diagnosis of acute lymphoblastic leukaemia (ALL) was made over a five-year period at the Royal Adelaide Hospital and Institute of Medical and Veterinary Science were studied. There were 34 patients with a median age of 47.5 years. Adequate follow-up was obtained on 33 patients, and their median survival was 5.4 months. The remission rate was 77% in the under-30 years age group, but only 15% in the over-30 years age group. The median duration of remission was 24 months while the median survival of remitters has not yet been reached. The median survival of non-remitters was two months with 100% being dead at 12-3 months. Of 20 patients without remission, seven died of haemorrhage and/or infection before an adequate trial of therapy had been completed, while nine patients had "adequate" intensive therapy but failed to achieve remission.

Acute Disease↗
PubMed1978

Epithelialization of the anterior chamber after transcorneal (McCannel) suture.

A 35-year-old woman developed epithelialization of the anterior chamber with secondary glaucoma, following the use of a transcorneal (McCannel-type) suture to repair a traumatic iridodialysis. Clinical photographs and histologic documentation illustrate the potential for this serious complication from this surgical technique.

Adult↗
PubMed1978

Listeria monocytogenes endophthalmitis with a black hypopyon.

A 68-year-old woman had a marked decrease in visual acuity, increased intraocular pressure, and acute iridocyclitis. She developed a pigmented hypopyon simulating an occult intraocular melanoma. Two anterior chamber paracenteses showed growth of Listeria monocytogenes. The patient received systemic intravenous penicillin, topical fortified gentamicin sulfate drops, and intraocular injections of cephaloridine. On discharge from the hospital after a two-week stay, visual acuity had improved and intraocular pressure had decreased.

Aged↗
PubMed1978

Saccadic velocity studies in Möbius syndrome.

Eight patients with Möbius syndrome were examined and their eye movements studied with horizontal saccadic velocity measurements. A marked decrease in velocity of horizontal saccades was noted, indicating both medial and lateral rectus weakness. Significant esotropia, when present, may be improved with conventional recession-resection surgery.

Abnormalities, Multiple↗
PubMedDate not supplied

Pharmacologic studies of cyclocytidine and arabinosylcytosine in dogs.

Cyclocytidine (cyclo-C) and arabinosylcytosine (ara-C) were compared as to distribution and metabolism in dogs after administration by the intravenous, subcutaneous, intramuscular, and oral routes. After cyclo-C, two metabolites were found in the plasma and urine--a hydrolytic product, ara-C, and its deaminated product, arabinosyluracil (ara-U). The urinary excretion of cyclo-C is rapid; Five hours after parenteral administration, 60% of the given drug is excreted; 45% as cyclo-C, 10% as ara-C, and about 5% as ara-U. In contrast, after similar injections of ara-C, 45% of the drug is excreted; 33% as ara-C and 12% as ara-U. When compared with those in human and mouse tissues, the deoxycytidine deaminase levels in dog tissues are extremely low. This agrees with the finding of low ara-U levels in dog plasma and urine after administering cyclo-C or ara-C. Regardless whether cyclo-C or ara-C is injected, the plasma decay curve of the resultant ara-C is biphasic, with calculated half-lives of 40 min and 2-2.5 hr. However, if ara-C is given, the plasma ara-C peak level is higher. Higher ara-C levels are also maintained throughout the measured 5 hr. There are no differences in pharmacologic disposition after iv, sc, or im administration of ara-C. This is also true for cyclo-C. These findings suggest that for both drugs, the above routes of administration may be equally effective. Neither cyclo-C nor ara-C is well absorbed after oral administration, and the drug concentration in the plasma is too low to be measurable. Whether the dog is fasted overnight or fed, the drug is excreted slowly. In 5 hr. no more than 3% is excreted, and by 12 hr. only 10% is excreted.

Administration, Oral↗