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Biomedical subjects

D Miller

Publications and source records attributed to D Miller.

At least 451 records · Page 25Linked to original sources
PubMed1989

Severe hypokalemia in thyrotoxic periodic paralysis.

Thyrotoxic hypokalemic periodic paralysis is an uncommon but sometimes fatal disease in which early recognition and therapy may prevent untoward complications. The case of a 26-year-old Chinese man who presented to the emergency department with rapidly progressive profound weakness and severe hypokalemia (serum potassium, 1.2 mEq/L) is presented. The patient required endotracheal intubation, ventilatory assistance, and intravenous potassium administration. Emergency medical evaluation and management of this entity are discussed.

Adult↗
PubMed1989

Management options for Propionibacterium acnes endophthalmitis.

The authors reviewed the management of nine culture-proven cases of Propionibacterium acnes endophthalmitis which presented at an average of 4 months after extracapsular cataract extraction (ECCE) and posterior chamber intraocular lens (PC IOL) implantation. The initial signs included a white intracapsular plaque (9/9), vitritis (9/9), granulomatous uveitis (4/9), nongranulomatous uveitis (5/9), hypopyon (4/9), beaded fibrin strands in the anterior chamber (3/9), and diffuse intraretinal hemorrhages (2/9). A variety of management schemes were used in these patients, including the following: topical and intravenous antibiotics alone; intraocular and topical antibiotic administration; pars plana vitrectomy with capsulectomy and intraocular antibiotic administration; and removal of all capsular remnants with PC IOL removal or exchange. The final visual acuities ranged from 20/20 to 20/60 in six eyes and 20/200 to 20/400 in three eyes. This review suggests that a variety of management options for P. acnes endophthalmitis appear to be successful. Based on the authors' experience, an algorithm for future treatment is offered.

Aged↗
PubMed1989

Herpes simplex virus type 1. A cause of the acute retinal necrosis syndrome.

The authors have isolated herpes simplex virus type 1 (HSV-1) from the vitreous of two patients with acute retinal necrosis. Clinical and laboratory data suggest that one case represented a primary HSV-1 infection, whereas the other case appeared to be a recurrent HSV-1 infection. In the primary case, changes on magnetic resonance imaging (MRI) suggest spread of the virus posteriorly to both optic tracts and the lateral geniculate ganglia. This case shares many features with the "von Szily" experimental model for HSV retinitis in the mouse.

Acyclovir↗
PubMed1989

The role of the limbal cornea in vision.

The eagle retina is bifoveal. The temporal fovea, which can resolve targets subtending half a minute or less must depend upon its peripheral cornea for such sharp resolution. Our studies showed the eagle cornea to be thinner, scatter less light and be more spherical than the human cornea. Further experimental studies determined the resolving power of the human peripheral cornea. Using, normal subjects, pinholes placed at the edge 8 mm dilated pupils yielded 20/30 visual acuity and normal contrast sensitivity measurements. Thus it is recommended that optical iridectomy be considered, in appropriate cases of corneal blindness with patches of clear peripheral cornea when no donor corneal material is available.

Animals↗
PubMed1989

Occupational strain and the incidence of coronary heart disease.

The hypothesis that men in high "strain" occupations have an increased risk of developing coronary heart disease was tested during an 18-year follow-up study from 1965-1983 of a cohort of 8,006 men of Japanese ancestry in Hawaii. There were no significant associations between the incidence of coronary heart disease and the individual job components of high psychologic demands and low job control or for the high strain interaction of these two characteristics. There were, in fact, trends of associations opposite to that predicted by the job strain model which were of borderline significance in multivariate analyses. Stratified analyses by level of acculturation showed similar inverse associations of job strain and coronary heart disease for the more Westernized men and no association for the more traditional men. There were also no significant associations among the various job characteristics and the major risk factors for coronary heart disease in this cohort. The disagreement of these results with those from other studies may be due to methodologic differences of using men whose usual and current occupations were the same in this study compared with using only current occupation in the other studies, the use of different methods of measuring job strain, or the possibility that men in this cohort perceive or react to occupational strain differently.

Adult↗
PubMed1989

Attitudes and behaviours of nurses towards the elderly in an acute care setting.

The study was designed to determine the attitudes of health care workers towards the elderly in acute care settings and to investigate variations in types of interaction between staff and elderly patients. A questionnaire and Kogan's Old People Scale were used together with direct non-participant observation of nurse-patient interaction. The questionnaire was completed by 50 registered nurses, 20 nursing aides, four degree nurses and eight volunteers. Of the four groups, the volunteers showed the most favourable attitudes, the registered nurses and degree nurses were virtually tied and the nursing aides were lower in the rating. Staff who expressed a preference for working in geriatrics and rehabilitation had a high correlation on the Kogan's Old People Scale: (r(77) = 0.38, P less than 0.01) and (r(77) = 0.32, P less than 0.01) respectively. It was also found that those who rated basic care as lower in importance to patient well-being than, for example, talking to patients, were more positive than were those who rated basic care higher in importance. In the second data collection, 47 female patients (mean age = 67.4 years) and 43 male patients (mean age = 71.5 years) were observed. It was found that 74% of patients spent almost 95% of their time inactively, either in bed or sitting in a chair. Neither age nor mental alertness relates to activity level, but mental alertness was found to be related to engaging in constructive activities. During the observation periods 41% of the patients did not interact with staff.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

The optical quality of the peripheral cornea.

The cornea can be considered to be an organ divided into a central and peripheral zone. Although the central cornea is responsible for producing a sharp retinal image, our experiments suggest that areas of isolated peripheral cornea can produce retinal images compatible to 20/30 visual acuity.

Contrast Sensitivity↗
PubMed1989

Cellular gene expression in papillomas of the choroid plexus from transgenic mice that express the simian virus 40 large T antigen.

Transgenic mice that contain the simian virus 40 (SV40) enhancer-promoter and large tumor (T) antigen gene develop papillomas of the choroid plexus. The tumors remain well differentiated on histological examination and express normal levels of tissue-specific mRNAs for transthyretin (TTR) and the 5-HT1C serotonin receptor, two differentiated cell markers. Both Northern (RNA) blot analysis and in situ cytohybridization have been used to monitor the steady-state levels of the mRNAs from the viral oncogene (T antigen) and from several cellular oncogenes. In situ hybridization demonstrated, in serial sections, increased levels of both T antigen mRNA and p53 mRNA localized in the tumor tissue but not in the normal brain tissue. The ratios of the steady-state levels of mRNA for p53/TTR and p53/L32, a ribosomal protein gene, were 2- to 20-fold higher in the tumor tissue than in the normal choroid plexus tissue. Several other oncogenes did not show elevated levels of mRNA in these tumors. p53 protein levels were not detectable in normal brain tissue, but p53 levels were very high in tumor tissue in which all of the p53 was found in a complex with the SV40 large T antigen. These data continue to show a close relationship between SV40 T-antigen-mediated tumorigenesis and the role of p53 in these tumors.

Animals↗
PubMed1989

Magnetic resonance imaging in central pontine myelinolysis.

Magnetic resonance imaging (MRI) was performed in two patients in whom a clinical diagnosis of central pontine myelinolysis (CPM) had been made. MRI showed lesions in the pons in both cases about 2 years after the illness, at a time when the spastic quadriparesis and pseudobulbar palsy had recovered. The persisting abnormal signals in CPM are likely to be due to fibrillary gliosis. Persistence of lesions on MRI means that the diagnosis of CPM may be electively, after the acute illness has resolved.

Adolescent↗
PubMed1989

Use of a holding technique to control the violent behavior of seriously disturbed adolescents.

Therapeutic holding is a treatment technique in which a violent patient is physically contained by people rather than by mechanical or chemical restraints or seclusion. Episodes of therapeutic holding that took place on an inpatient adolescent psychiatric unit over an 18-month period were examined retrospectively through chart review and review of written audits of each episode. During that period, 22.8 percent of the patient population experienced at least one episode of therapeutic holding. Patients requiring this intervention were more likely to be younger and, when day at risk were controlled, to be male and to have had longer stays on the unit. The technique enabled patients to regain behavioral control after a mean of 21.2 minutes, a much shorter period of containment than the four to 16 hours reported in studies of seclusion.

Adolescent↗
PubMed1989

Severe "silent" mitral regurgitation. A potentially reversible cause of refractory heart failure.

Hemodynamically critical ("severe") mitral regurgitation is usually associated with an audible (if not loud) systolic murmur and signs of left ventricular volume overload. However, "silent" severe mitral regurgitation is being increasingly recognized. We review the case histories of nine patients with silent hemodynamically important mitral regurgitation (associated with acute myocardial infarction and chronic valvular, hypertrophic, and ischemic heart disease), six of whom survived mitral valve replacement, of whom five are alive and functioning well more than three years postoperatively. Performance of left ventriculography early in the hospital course of patients with severe unexplained congestive heart failure (with normal or near-normal left ventricular systolic function assessed noninvasively) identifies patients with severe silent mitral regurgitation who may have long-term benefit from mechanical therapy.

Adult↗
PubMed1989

Hemodynamic effects of mivacurium chloride administered to patients during oxygen-sufentanil anesthesia for coronary artery bypass grafting or valve replacement.

The hemodynamic effects of mivacurium chloride were studied in 54 adult cardiac patients anesthetized with midazolam and sufentanil. After baseline data were collected, a placebo (N = 9) or mivacurium was administered over 60 seconds, the latter in doses of 0.15 (N = 18), 0.20 (N = 18), or 0.25 (N = 9) mg/kg. Measurements were repeated 2, 5, and 10 minutes later. Baseline measurements were similar. A slight decrease in heart rate over time reached statistical significance in several groups including the control group. Mean arterial, mean pulmonary arterial, pulmonary arterial occlusion, and right atrial pressures and cardiac output did not change, nor did systemic and pulmonary vascular resistances and cardiac index. Besides the decrease in heart rate, the only hemodynamic change to reach statistical significance was an increase in stroke volume in patients given mivacurium 0.25 mg/kg. Significant hypotension occurred in two patients; in one, a sudden decrease in mean arterial pressure of 24% occurred 1 minute after mivacurium 0.20 mg/kg. Blood pressure was restored by ephedrine 10 mg. In the other patient, given mivacurium 0.25 mg/kg, mean arterial pressure decreased 50% from 73 to 37 mm Hg. Recovery was rapid without treatment. It is concluded that mivacurium administered in doses of 0.15 to 0.25 mg/kg over 60 seconds to cardiac patients is associated with few significant hemodynamic effects. However, a small number of patients may experience significant transient hypotension when given doses greater than of 0.15 mg/kg, two times the ED95.

Adult↗
PubMed1989

Administrative response to issues of health-care worker safety and HIV exposure.

This last example raises the philosophical side of the cost question. The guarantee of a safe work environment is a goal. The efforts to achieve this goal are balanced with the mission of the hospital to provide medical care to those in need. The leadership of the hospital adjusts this balance through the endorsement of policies and through funding of programs. The HIV epidemic has raised ethical, social and financial questions that we are all working to answer.

Acquired Immunodeficiency Syndrome↗
PubMed1989

The elastic modulus of central and perilimbal bovine cornea.

Data on the elastic properties of corneal tissue are needed to define the parameters involved in a model for radial keratotomy. Using bovine corneal tissue, we measured stress-strain relationships of tissue at different locations in the cornea. From this data we calculated Young's modulus of elasticity of five specimens at peripheral and central corneal locations. Increasing levels of stress produced increased resistance to stretch, a property typical of soft biologic materials such as cornea. Linear regression analysis of the data showed that the elastic modulus of the peripheral tissue was greater than that of central tissue at all values of applied stress. These linear relationships were statistically different, using an analysis of covariance, indicating that peripheral corneal tissue is stiffer than central corneal tissue. This information supports the suggestion that a peripheral circular ligament of corneal tissue exists and helps to maintain the curvature of the cornea. It is the disruption of this ligament that is believed to cause some of the change in corneal curvature when radial keratotomy is done.

Animals↗