PubMed Health⌕ Search

Biomedical subjects

K Hannah

Publications and source records attributed to K Hannah.

13 recordsLinked to original sources
PubMed2003

[Corneal edema in pseudophakia. A case report].

Pseudophakic bullous keratopathy is one of the most common complications of intraocular lenses, which explains the high rate of this condition in series of patients experiencing corneal grafts. It is caused by irreversible damage to the endothelial layer of the implanted eye involving the artificial lens, and occurs either during cataract extraction or after the operation. Intraoperative endothelial protection and the choice of an appropriate lens may contribute to decreasing this secondary disease, which can have severe consequences for many patients whose corneal graft may not restore their visual potential as well as expected. We report a clinicopathological case of a 59-year-old male, previously operated on for cataract in both eyes with an anterior chamber lens. A bilateral corneal edema occurred a few years after the operation, with a bilateral decrease in vision as a consequence. A corneal graft was performed in 2000 on the left eye in order to improve the patient's visual autonomy. The best treatment of this condition remains prevention, avoiding the use of this type of intraocular lens, whose main complication is corneal edema.

Cataract Extraction↗
PubMed1995

The role and scope of data management in a changing health services delivery environment.

Data and information are essential to rational decision making and the good management of the health services delivery systems in any country. The restructuring of health systems world-wide is impacted by these concepts. The information systems necessary to provide data and information can be characterized by a number of interdependent domains. Data Management is central because data provides the binding principle: Applications are processing Data, Technology is transferring data, Methodology is identifying how data is captured and where it is used in order to minimize the cost of data as a resource. The whole purpose is to serve the Business of Health Services Delivery. Each domain is interdependent with the others at an intersection between the domains.

Database Management Systems↗
PubMed1994

Reversed-phase LC assay method for deoxycholate in influenza vaccine.

Sodium deoxycholate is used for the disruption of particles in the manufacturing of some influenza vaccines. Residual deoxycholate in inactivated vaccines is currently determined using a labour-intensive colorimetric method which lacks complete specificity. An alternative assay method for residual deoxycholate in vaccine preparations was developed using reversed-phase LC. Cholic acid was used as internal standard and the ratio of internal standard to test solute was used for all calculations. Prior to LC analysis, deoxycholic acid was concentrated by solid-phase extraction, a procedure that also removed proteinaceous material in vaccine samples. The clean-up/concentration procedure recovery was examined using untreated samples and was found to be quantitative. The linearity range of the LC method was between 3 and 200 micrograms ml-1, with a limit of detection of approximately 0.4 micrograms on column, and a lower limit of quantitation of 1.6 micrograms on column. Replicate assays during intra-and inter-day experiments gave acceptable levels of variability. The DCA content of samples from three lots of influenza vaccine varied between 10 and 16 micrograms ml-1. These values were appreciably lower than those measured spectrophotometrically, indicating the higher specificity of the LC method.

Cholic Acid↗
PubMed1992

Interference is controlled by segment 2 and possibly by segment 8 of the nondefective interfering influenza virus variant A/FM/1/47-MA.

On mouse adaption of A/FM/1/47, a variant, A/FM/1/47-MA (FM-MA), that had acquired the properties of increased virulence and interference was produced. Coinfection of cells with FM-MA and prototype strains of influenza virus yielded > 100-fold more FM-MA virus than prototype virus, whereas coinfection with the same prototype strains and the parental A/FM/1/47 virus produced equivalent yields, indicating that FM-MA had acquired mutations that confer the property of interference during mouse adaption. FM-MA is a nondefective interfering virus that grows to a high titer in vivo and in vitro. It has previously been shown that segments 4, 7, and 8 and possibly segment 5 account for the increased virulence. In this study we show by genetic analysis of FM-MA x A/HK/1/68 reassortants that segment 2, coding for the polymerase-associated protein PB1, and possibly segment 8, encoding the NS1 and NS2 proteins, control the ability of FM-MA to interfere. Interference could not be overcome by increasing the titer of the coinfecting strain, but delaying FM-MA infection by 4 to 6 h did avoid interference. During interference of A/HK/1/68, protein synthesis was inhibited by less than 65% throughout coinfection. Given the kinetics of interference and the small perturbation in protein synthesis, interference appeared to occur at the level of late genome replication or virus assembly. Virulence and interference in FM-MA were not linked. An interfering avirulent FM-MA x A/HK/1/68 reassortant, E07, was capable of protecting mice against lethal pneumonia due to a virulent noninterfering reassortant, H04.

Genetic Variation↗
PubMed1985

Performance and physiological effects of acceleration-induced (+ Gz) loss of consciousness.

Loss of consciousness (LOC) was intentionally induced by exposing eight volunteers to individually-titrated levels of head-to-foot acceleration (+ Gz) using 2- and 4-s onset rates (mean = 6.1 + Gz required to induce LOC) and a gradual, .067 G X s-1 onset rate (mean = 7.2 Gz required). Subjects were trained over a prior 2-week period on a multitask battery comprising three simultaneously executed tasks representative of those required in piloting, and then centrifuged to LOC at each of the three onset rates on alternate days. Performance was assessed for 5 min prior and 7 min after each LOC. Primary results indicated: a) significant and substantial impairment in the two discrete response secondary tasks (choice reaction time and arithmetic computation), with mean recovery to pre-LOC levels within 3 min on each task, b) no group mean impairment for the primary, compensatory tracking task, c) substantial individual variation in physiologically and behaviorally defined recovery from LOC, d) a negative influence of aerobic fitness on G tolerance and LOC recoverability, and e) that recovery effects were not generally dependent upon onset rate. Mean absolute incapacitation (head dropped) for the rapid onset rates was 12.1 s. For the gradual onset rate, mean absolute incapacitation was 16.6 s. Mean relative incapacitation (head erect, no voluntary task engagement) for the rapid onset rates was 11.6 s; for the gradual onset rates, mean relative incapacitation was 15.7 s. Evidence for retrograde amnesia effects was equivocal.

Acceleration↗
PubMedDate not supplied

Transforming a health care system: managing change for community gain.

The research undertaken describes a regional health authority's approach to managing a shift away from acute hospital care towards more community-based, health promoting service orientations in line with new legislated responsibilities. It builds on earlier research of province-wide efforts to create new ways of organizing work within new regional health authority structures. The initial study explored "what matters most", to managing the restructuring of Alberta's health care system and identified ten variables as critical to the transition to regionalization in Alberta. Four were seen to be pre-requisites to effective change: sustaining political will; pacing; resourcing; and, committing to change. Six others were described as continuous process variables; leading; communicating; informing; learning; planning; and, adjusting. This case study looks closely at the operation of these variables in a specific change process within the wider context of the Alberta health reforms.

Canada↗