PubMed HealthSearch

Biomedical subjects

C Hanna

Publications and source records attributed to C Hanna.

At least 19 recordsLinked to original sources

The intensive mothercraft program--a report.

A report on the Intensive Mothercraft Program (IMP) developed at The Queen Elizabeth Hospital (TEQH) Adelaide. This program was developed in 1987 mainly in response to needs demonstrated by parents, who were physically and/or intellectually disabled.

Persons with Disabilities

Detection apparatus for multiple heterogeneous chemiluminescence immunoassay configurations.

We describe an apparatus for measuring signals emanated from two heterogeneous chemiluminescence immunoassay (CLIA) configurations: antibody-coated polystyrene beads, in reaction tray wells, and microparticles captured by a porous matrix. An optics and fluidics design which allows the use of a common detection head for these two different assay configurations is described. The detection head moves along three Cartesian coordinates to create a localized light-tight compartment around each individual disposable reaction vessel. Reproducibility of the light seal, trigger solution delivery, and mixing is achieved for acridinium-labeled CLIA. The coated polystyrene beads configuration is tested using beta HCG, CEA, and TSH assays. The microparticle-capture configuration is tested using beta HCG and HBsAg assays. The microparticle capture CLIA has shorter incubation times and the potential for ease of automation.

Data Interpretation, Statistical

Genetic dissimilarity of commensal strains of Candida spp. carried in different anatomical locations of the same healthy women.

Candida spp. carriage and strain relatedness were assessed in 52 healthy women at 17 anatomical locations by using an isolation procedure which assesses carriage intensity and by using a computer-assisted DNA fingerprinting system which computes genetic similarity between strains on the basis of the patterns of Southern blots probed with the moderately repetitive sequence Ca3. Candida spp. were cultured from 73% of the test individuals, most frequently from the oral (56%), vulvovaginal (40%), and anorectal (24%) regions. Half of the test individuals with Candida spp. carried the organism simultaneously in more than one of the three general areas of carriage. Isolates from different body locations of the same individual were either completely unrelated, identical, or highly similar but nonidentical. In 11 cases in which Candida spp. were simultaneously isolated from the oral cavity and vaginal canal, seven pairs of isolates were genetically unrelated and four pairs were similar but nonidentical. In the latter cases, the isolate pairs each appear to have arisen by genetic divergence from a single progenitor. A comparison of the genetic relatedness of isolates from different individuals further uncovered a single strain which was vaginospecific in the Iowa City, Iowa area and reduced genetic diversity among vulvovaginal strains compared with those isolated from other body locations. These results suggest that strains adapt to different anatomical locations and, conversely, that in a healthy individual there is anatomical selection of vaginotropic, anotropic and orotropic strains of Candida spp.

Adult

Evaluation of drugs in ointment for mydriasis and cycloplegia.

Ointment preparations of cyclopentolate hydrochloride and tropicamide were compared with aqueous drops of these medications for the production of mydriasis and/or cycloplegia in clinic patients. Mydriasis and/or cycloplegia could be accomplished by the single application of a minute volume (around 0.005 ml) of ointment containing these drugs. With the use of ointment preparation, ocular irritation was minimal, and there was no interference with subsequent ocular examination. A delivery system was devised with a piece of silicone-rubber tubing that was filled with an ointment preparation. By squeezing the tubing, a minute volume (about 0.005 ml) of ointment preparation was expressed.

Accommodation, Ocular

Ocular penetration of topical chloramphenicol in humans.

Commercial ophthalmic chloramphenicol solutions and ointments were applied to human eyes, and the concentrations of chloramphenicol in aqueous humor and tear samples were analyzed using gas-liquid chromatography. Within several minutes after a single application of 0.5% chloramphenicol solution, the tear concentrations of the drug had fallen below 1 mg/liter, the minimal bacteriostatic concentration for many ocular pathogens. Repeated drops of 0.5% chloramphenicol solutions during several hours were required to produce an aqueous humor concentration of 1 mg/liter. A single application of 1% chloramphenicol ointment gave prolonged drug concentrations in the tears and aqueous humor, falling to 1 mg/liter in two to four hours. The repeated use of chloramphenicol solution or ointment was well tolerated by the patients. We conclude that the penetration of chloramphenicol in the anterior segment of the eye is best carried out by the repeated application of chloramphenicol ointment.

Administration, Topical

Endothelial cell population changes of human cornea during life.

A photo slit lamp was used to obtain color, specular reflex, high magnification photographs of the corneal endothelium of subjects ranging in age from 3 to 88 years. Multiple areas of the cornea were examined to determine the endothelial cell population. No appreciable difference in cell density was found between the right and left eyes of the subjects nor between male and female subjects of similar age. Apparent defects in the endothelial cell coverage of Descemets membrane were found in subjects as young as 20 years of age and with increased frequency in older age groups. These defects were at times associated with variations in endothelial cell populations between the central and peripheral cornea. The average corneal cell population fell from nearly 1 million cells in the first years of life to about one third that number by the eight decade of life.

Adolescent

Use of dilute drug solutions for routine cycloplegia and mydriasis.

Clinic patients and students were given several regular drops of commercial 10% phenylephrine HCl, and 1.0% cyclopentolate HCl or 1.0% tropicamide HCl. The drops were given three times at five-minute intervals. Mydriasis and cycloplegia were determined and compared with the results obtained by using one of the following: microdrops (0.005 or 0.01 ml) of a mixture of 5% phenylephrine HCl and 0.5% tropicamide HCl, or regular drops of mixtures of 1% phenylephrine HCl, or 0.4% hydroxyamphetamine hydrobromide with 0.1% cyclopentolate HCl, or 0.1% tropicamide in a vehicle of 1.6% or 1.0% methylcellulose 400, or artificial tears or lubricants (Absorbobase, Contique, Isopto Tears, Liquifilm, Lyteers, Ultra Tears). Except for an initial lag in the production of mydriasis with the diluted mixtures, the results were similar for all preparations. The diluted solutions produced little ocular irritation or tearing.

Adolescent

Route of absorption of drug and ointment after application to the eye.

Chloramphenicol, tetracycline hydrochloride, sodium sulfacetamide, and fluorescein sodium prepared in both aqueous solutions and ointments were placed in the conjunctival sac of humans. Each drug soon was tasted in the back of the mouth with no difference being noticed with the use of aqueous solution or ointment. Tetracycline and fluorescein studies showed that systemic absorption were similar regardless of whether solution or ointment were used. Furthermore, it was found that the ointment passed through the lacrimal drainage system and into the nose and throat. The ocular contact time of ointment with the eye is greater than that of water, and ointment is much more slowly absorbed via the lacrimal drainage system. Both the drugs and the ointment base applied topically to the eye travel through the nasolacrimal system as the way of elimination when given in the small volumes that are held by the conjunctival sac.

Absorption

Ocular penetration of chloramphenicol. Effects of route of administration.

Chloramphenicol was applied topically to the eye in ointment, as a powder, or injected subconjunctivally and intravenously in rabbits. Aqueous humor samples were taken at varying time intervals up to six hours and analyzed for chloramphenicol using gas-liquid chromatography. The topical route using ointment and the subconjunctival injection route produced bacteriostatic concentrations of chloramphenicol in the aqueous humor lasting for several hours, while the topical powder and intravenous routes yielded relatively low concentrations. As compared with the other means of drug delivery, ointment was the most efficient in that it provided the highest aqueous concentration per total amount of drug administered.

Animals

An ultrastructure study of posterior polymorphous dystrophy of the cornea.

The cornea from an early developing and uncomplicated case of posterior polymorphous dystrophy in a 15-year-old boy shows a thin abnormal Descemet's membrane and reduced number of endothelial cells as the primary findings. Ultrastructurally, the membrane was composed of a very thin, three-dimensional lattice pattern layer covered by layers of fibrous material. This lattice pattern is normally formed between late fetal and early adolescent life. The 3 previously reported histologic cases of this entity were from cases with long-standing corneal opacities in the late third to fifth decade of life with additional corneal changes. However, in each case the lattice pattern layer of the membrane was abnormally thin. This report suggests that a progressive form of posterior polymorphous dystrophy of the cornea is due to cells forming abnormal Descemet's membrane beginning in late fetal life to soon after birth.

Adolescent

Effects of dimethyl sulfoxide on ocular inflammation.

The anti-inflammatory properties of topical ocular dimethyl sulfoxide (DMSO) were investigated using a standard experimental model of an acute inflammatory ocular inflammation. Ninety percent and 100% DMSO aggravated the inflammatory response, 50% to 70% DMSO had similar responses as the control eye; however, 30% DMSO had definite anti-inflammatory properties. Dexamethasone 0.1% was superior to 30% DMSO as an anti-inflammatory agent. From this study it is evident that high concentrations of DMSO are irritating to the inflammatory ocular model used while lower concentrations have anti-inflammatory properties. The two side effects of skin irritation at the site of application and breath odor may be the subjective influence that leads certain patients to report a beneficial effect of DMSO treatment in ocular inflammation.

Acute Disease

Use of drugs in ointment for routine mydriasis.

The mydriatic effect produced by ointment preparations of cyclopentolate 1%, tropicamide 1%, and phenylephrine hydrochloride 10% was compared to the mydriasis elicited by the aqueous solutions of the same concentrations of drugs in children and adults. There was no difference in the amount of mydriasis produced by one instillation of a very small volume of the drug in ointment in one eye when compared to multiple instillations of the aqueous solution of the same drug in the contralateral eye in 30 minutes. There were no complaints of ocular irritation when the ointment preparations were instilled into the eye; however, there were frequent complaints with the use of these drugs in aqueous solutions.

Adolescent

Idiopathic chorioretinal effusion: An analysis of extracellular fluids.

A case of nonrhegmatogenous retinal detachment with choroidal detachment was seen 3 weeks after onset and was evaluated clinically with emphasis on the fluid contents from one eye. The right eye showed slight subretinal fluid and minimal RPE pigmentary mottling. The left eye was severely involved with a near flat anterior chamber, a 360 degrees peripheral serous retinal detachment with shifting fluid and 360 degrees choroidal separations. Fluorescein showed mottled retinal pigment epithelium changes in each eye. Cell free samples of the subretinal fluid were high in protein (16.5 gm/100 ml) with a near absence of the alpha-2 fraction. Epichoroidal fluid from the choroidal detachments exhibited a protein content and makeup similar to that of normal plasma. The concentration of protein in the cerebrospinal fluid was elevated (0.096 gm/100 ml) without evidence of inflammatory changes. Ultrastructural examinations of sclera revealed a normal structure. There was no indication of the cause of the elevated protein content of the subretinal and spinal fluids. Following subretinal and epichoroidal fluid evacuation, the patient was treated with systemic steroids. The retinal and choroidal separations subsided slowly over several months, leaving multiple retinal pigment epithelial pigmentary clumps with drusen-like centers. A more appropriate name for this entity is idiopathic chorioretinal effusion.

Blood Proteins

Recurrent tapioca melanoma of the iris and ciliary body treated with the argon laser.

A 25-year-old white woman underwent iridocyclectomy for an iris tumor. Clinically, histologically, and ultrastructurally this tumor was the same as a recently reported tapioca melanoma of the iris. During the next four months, there were recurrent growths on the ciliary body that we treated with the argon laser through a three-mirror lens. No further recurrences of the tumor were noted three years later.

Adult

Effect of drug vehicle on human ocular retention of topically applied tetracycline.

Tetracycline hydrochloride--as a 1% suspension in oil, 1 and 2% suspension in ointment, and 1 and 2% solution in water or balanced salt solution USP--was applied once to the conjunctival cul-de-sacs of volunteers and patients before cataract extraction. The tear film concentrations of drug were maintained above a bacteriostatic level in excess of six hours for 1 and 2% tetracycline in ointment, less than two hours for 1% tetracycline in oil, and less than 30 minutes for 1 and 2% tetracycline in water or balanced salt solution. The 2% tetracycline in ointment produced the highest tear film levels of drug. The 1% tetracycline in oil induced excessive lacrimation and much of the drug was washed from the conjunctival surface. The tear film levels of the drug were mirrored by the maintenance of bacteriostatic levels of tetracycline in the aqueous humor for 1 1/2 hours with 2% tetracycline in ointment. Whereas 1% tetracycline in ointment produced drug levels approaching bacteriostasis in the aqueous humor, 1% tetracycline in oil produced only trace levels of the drug within the anterior chamber. The ointment acted as a depot for the suspended drug and most of the drug in the absence of excessive tearing was lost from the conjunctiva via the lacrimal system.

Administration, Topical