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Biomedical subjects

K Hall

Publications and source records attributed to K Hall.

At least 37 records · Page 2Linked to original sources
PubMed2001

Possible medication errors in home healthcare patients.

OBJECTIVE: To determine the frequency of possible medication errors in a population of older home healthcare patients according to expert panel objective criteria. DESIGN: A cross-sectional survey. SETTING: Two of the largest urban home healthcare agencies in the United States. PARTICIPANTS: Home healthcare patients age 65 and older admitted to selected offices of these agencies between October 1996 and September 1998. MEASUREMENTS: We used two sets of consensus-based expert panel criteria to define possible medication errors. The Home Health Criteria identify patients with patterns of medication use and signs and symptoms that indicate sufficient likelihood of a medication-related problem to warrant reevaluating the patient. The Beers criteria identify medications that experts have deemed generally inappropriate for older patients. RESULTS: The 6,718 study subjects took a median of five drugs; 19% were taking nine or more medications. A possible medication error was identified for 19% of patients according to Home Health Criteria, 17% according to the Beers criteria, and 30% according to either. Possible errors increased linearly with number of medications taken. When patients taking one to three medications were compared with those taking nine or more drugs, the percentages with possible errors were, respectively, 10% and 32% for the Home Health Criteria, 8% and 32% for the Beers criteria, and 16% and 50% for both. CONCLUSION: Nearly one-third of the home healthcare patients surveyed had evidence of a potential medication problem or were taking a drug considered inappropriate for older people. More-effective methods are needed to improve medication use in this vulnerable population.

Aged↗
PubMed2001

Radiographic analysis of low contact stress meniscal bearing total knee replacements.

BACKGROUND: Meniscal bearing total knee replacements were developed to decrease the contact stresses on polyethylene and to reduce polyethylene wear. The kinematics of meniscal bearing knee replacements is poorly understood. The present study was designed to evaluate, with radiographic analyses, the motion of the meniscal bearings and the femoral rollback of the Low Contact Stress meniscal bearing knee replacement during knee flexion. METHODS: Eighty-one Low Contact Stress meniscal bearing total knee replacements in seventy-six male patients were assessed on fluoroscopically centered lateral radiographs made with the knee in full extension and in full flexion at an average of six years (range, twenty-four to 147 months) after the operation. The distance and direction of motion of the meniscal bearings and the center contact position of the femoral condyles were measured. Knee evaluations were performed with use of the Knee Society rating system. RESULTS: The average range of motion of the knees, measured on lateral radiographs, was 90 degrees (range, 45 degrees to 136 degrees). As they moved from terminal extension to terminal flexion, thirty-nine knees (48%) exhibited anterior motion of both bearings and sixteen (20%) demonstrated posterior motion of both bearings. Ten knees (12%) had reciprocal motion of the two bearings (one bearing moving anteriorly and one bearing moving posteriorly) with flexion, nine knees (11%) had motion of only one bearing, and seven knees (9%) had no motion of either bearing. When moving from full extension to full flexion, eighteen knees (22%) demonstrated femoral rollback, six knees (7%) showed no change in the position of femoral contact, and fifty-seven knees (70%) exhibited anterior sliding of the femoral condyles. Flexion of the knees demonstrating femoral rollback averaged 104 degrees (range, 76 degrees to 128 degrees), and flexion of the knees demonstrating anterior sliding averaged 94 degrees (range, 45 degrees to 125 degrees). The difference was significant (p = 0.03). According to the Knee Society rating system, the average clinical score for the entire group was 76 points (range, 27 to 100 points) and the average functional score for the entire group was 72 points (range, 30 to 100 points). The average clinical score was 79 points (range, 27 to 98 points) for the knees that exhibited anterior sliding of the femoral condyles and 87 points (range, 52 to 100 points) for those exhibiting femoral rollback (p = 0.09). The average functional scores were 64 points (range, 30 to 100 points) and 72 points (range, 45 to 100 points), respectively (p = 0.15). CONCLUSIONS: Radiographic analysis of meniscal bearing total knee replacements demonstrated an average anterior motion of both the medial and the lateral meniscal bearing of 4.7 mm (range, 1 to 14 mm) in thirty-nine knees (48%) as they moved from terminal extension to terminal flexion. Sixty-three knees (78%) demonstrated no femoral rollback as they were flexed. Knees with anterior sliding of the condyles had a significantly smaller average range of flexion (p = 0.03) and a lower average Knee Society score than did knees demonstrating femoral rollback. We believe that lack of rollback indicates a functional insufficiency of the posterior cruciate ligament.

Aged↗
PubMed2001

Microbiological and chemical analyses of stainless steel and ceramics subjected to repeated soiling and cleaning treatments.

Stainless steel and ceramic surfaces were subjected to repeated soiling and cleaning procedures, using a milk powder soil inoculated with Pseudomonas aeruginosa and Staphylococcus aureus, followed by spraying with water with or without 0.1% (vol/vol) nonionic detergent. Test surfaces were removed after 1, 5, 10, and 20 soiling-cleaning cycles and were analyzed for attached microorganisms (total viable count of bacteria removed by swabbing and percentage of coverage of cells plus soil stained with acridine orange). Surfaces were additionally examined using a range of analytical techniques: X-ray photoelectron spectroscopy (XPS), dynamic and imaging secondary ion mass spectroscopy (SIMS), and time-of-flight SIMS. Both microbiological and chemical analyses revealed an accumulation of material over the cycles to a maximum level. Surfaces were conditioned rapidly to saturation with organic material within one cycle (XPS), whereas fouling by microorganisms was less rapid (five cycles). Cleaning with detergent tended to retard the cumulative fouling process when compared with spray cleaning using water alone. The methods described provide a more realistic scenario for testing the cleanability of surfaces routinely found in food processing locations and for screening novel cleaning regimens and/or surface materials. The analytical techniques provide additional information on the kinetics of soiling, which complement the more familiar microbiological methods.

Bacterial Adhesion↗
PubMed2001

Reactive and clonal thrombocytosis: proinflammatory and hematopoietic cytokines and acute phase proteins.

BACKGROUND: We quantitated proinflammatory and thrombopoietic cytokines in reactive thrombocytosis (RT) and clonal thrombocytosis (CT) to identify a cytokine profile that might aid in the distinction of these two disorders. METHODS: Serum levels of cytokines relevant to platelet biology--interleukins 3, 6, 11, and 1beta; thrombopoietin; tumor necrosis factor alpha; and C-reactive protein (CRP)--were measured by enzyme-linked immunosorbent assay in healthy subjects and in patients with CT and RT. RESULTS: Interleukin-6 and CRP levels were higher in RT patients than in controls or CT patients. Interleukin 1beta levels were higher in the RT group than in the CT and control groups. CONCLUSIONS: In RT, IL-6, IL-1beta, and CRP levels are elevated. In both RT and CT, IL-11 is elevated, but thrombopoietin levels are not.

Adult↗
PubMed2001

Physician services in an academic neurology department: using the resource-based relative-value scale to examine physician activities.

The inability of physician managers and decision makers to critically analyze the resource utilization of physicians has hindered a more comprehensive understanding of the role of neurologists in the patterns and organization of medical practice. This article outlines an approach for using the physician work relative value units (RVUs) in the Medicare Fee Schedule (MFS) to address this problem and profile physician clinical activities in a comparative manner. These techniques are then used to profile the physician services associated with the neurology department at a large academic hospital. All 28,048 physician services associated with a neurology department in 1995 were studied. Using billing data, physician work RVUs were assigned to each service and the results analyzed by major services, type of service, and physician workload for physician work RVUs and physician charges. For the average service, mean physician charges were $187 per service while median physician charges were $120. Mean physician work RVUs per service averaged 1.3 RVUs, and the median was 0.94 per service. Of all the services provided in the neurology department, 65 percent are visits and consultations, while medicine services (e.g., nerve conduction studies, needle electromyography, neuropsychological testing, and electroencephalogram) make up 31 percent. All the other services combined represented less than five percent of the services in the department. The top five physicians in the department account for 33 percent of all physician work RVUs in the neurology department. Using the physician work relative values in the MFS provides a unique perspective for analyzing and understanding neurologists' work activities.

Academic Medical Centers↗
PubMed2001

Repressive adaptation in children with cancer: a replication and extension.

Prior research has shown a higher incidence of a repressive adaptive style in children with cancer. To explore whether repressive adaptation in this population is premorbid or reactive, adaptive style was assessed longitudinally in children with cancer at the time of diagnosis and at 6 months and 1 year after diagnosis. Comparison groups included healthy children and children with other serious but nonmalignant chronic illnesses. At diagnosis, children with cancer showed a higher incidence of a repressive adaptive style than healthy children, and the incidence of repressive adaptation remained stable over time. Children with other chronic illnesses also showed levels of repressive adaptive style comparable to the cancer group. These findings suggest a shift toward repressiveness in response to the diagnosis of cancer that is then maintained over time and necessitate further examination of the health consequences of adaptive style in this population.

Adaptation, Psychological↗
PubMed2000

A study of dose delivery in small segments.

PURPOSE: Use of conformal therapy techniques increases the number of beams used in order to obtain better conformation of the treated volume to the planning target volume. As the number of beams increases, the number of monitor units (MU) for each beam decreases. In this work we have studied, the influence of low MU on dose and homogeneity. METHODS AND MATERIALS: To study the field symmetry and flatness, films were irradiated. The "dose" for each field was always 60 MU; but it was divided into different segment sizes: 2 segments of 30 MU, 3 segments of 20 MU, and so on up to 12 segments of 5 MU. After being developed, films were scanned and analyzed using a densitometer. The measurements were carried out for three X-ray energies: 6 MV, 10 MV, and 18 MV. RESULTS: Each measurement was repeated twice for each energy, and the results were equal. The means of the symmetry and flatness values obtained for each energy are lower than the commonly accepted limits. CONCLUSION: The dose delivered by adding small segments is equivalent to the dose delivered by a conventional segment with our Philips Linacs SL15 and SL20.

Phantoms, Imaging↗
PubMed2000

Quantification of polycyclic aromatic hydrocarbons in the NIST standard reference material (SRM1649A) urban dust using thermal desorption GC/MS

A thermal desorption GC/MS technique has been developed for the quantification of polycyclic aromatic hydrocarbons (PAHs) in airborne particulate matter using the NIST Standard Reference Material (SRM1649a) Urban Dust. The technique was developed using standard linearity tests in order to establish optimum sample weights and optimum desorption and chromatographic parameters. This direct analysis technique eliminates the use of solvents in the sample preparation (reducing volatile component losses) and also significantly reduces the sample preparation time (no extraction procedure). The technique has been shown to give linearity in terms of the overall TIC response as well as for a prominent series of n-alkanes (C20-C33) and 10 NIST priority PAHs, 8 of which have been quantified. The technique is reported to be uniquely sensitive (PAH concentrations 2-6 mg kg(-1)) and reproducible (MW = 178-228 SD < or =0.228 mg kg(-1), < or =7%; MW = 252 SD < or =0.922 mg kg(-1), < or =33%) over the range of sample weights (1-5 mg). Such sample weights illustrate that the technique can be equally applied to the analysis of airborne particulate samples collected over short time periods (24-48 h) using only commonly used low-volume collection devices.

Journal Article↗
PubMed2000

Internet use amongst New Zealand general practitioners.

AIMS: To assess how extensively New Zealand doctors are using medical information on the Internet, and to examine how the new technology is affecting their practice of medicine. METHODS: All general practitioners (GPs) known to be working in Otago and Southland were asked to complete a postal questionnaire regarding their use of the Internet and their impressions of patient use of online medical resources. RESULTS: Of 259 questionnaires mailed out, 168 (65%) were returned by GPs currently in practice. Of those, 114 (68%) said they used the Internet at least monthly. A total of 71% of GPs had patients who indicated they had sought medical information from the Internet. Nearly half of respondents expressed concerns that the Internet could have unwelcome effects on the doctor-patient relationship. CONCLUSIONS: Internet use among New Zealand doctors and patients is widespread, and is likely to have significant impact on medical practice now and in the future. While the potential benefits of the new technology are numerous, the Internet may become a source of conflict between doctors and patients.

Data Collection↗
PubMed2000

Phase II evaluation of 24-h continuous infusion topotecan in recurrent, potentially platinum-sensitive ovarian cancer: A Gynecologic Oncology Group study.

OBJECTIVES: The aim of this study was to develop an alternative effective and more convenient administration schedule for intravenous topotecan when used as palliative treatment in ovarian cancer. METHODS: The Gynecologic Oncology Group conducted a Phase II trial of 24-h infusional topotecan (8.5 mg/m(2)) with treatment repeated every 3 weeks in 29 patients with platinum-sensitive recurrent ovarian cancer (prior response to platinum-based chemotherapy with a minimum treatment-free interval >/=6 months). RESULTS: The major toxicities of therapy were grade 4 neutropenia and thrombocytopenia which developed in 86 and 14% of patients, respectively. Other severe side effects were uncommon. Only 2 partial responses (7%) were observed in the 28 patients evaluable for response. CONCLUSIONS: Despite the relatively favorable ovarian cancer patient population treated in this trial (platinum-sensitive recurrent disease), the response rate was disappointingly low. Considering the three- to fivefold higher objective response rates observed in other trials employing topotecan in individuals with platinum-sensitive ovarian cancer utilizing a 5-day treatment program (delivered every 3 weeks), the results of the current study provide strong support for the conclusion that clinically relevant antineoplastic activity of this agent is highly schedule dependent.

Adult↗
PubMed2000

A theory for the membrane potential of living cells.

We give an explicit formula for the membrane potential of cells in terms of the intracellular and extracellular ionic concentrations, and derive equations for the ionic currents that flow through channels, exchangers and electrogenic pumps. We demonstrate that the work done by the pumps equals the change in potential energy of the cell, plus the energy lost in downhill ionic fluxes through the channels and exchangers. The theory is illustrated in a simple model of spontaneously active cells in the cardiac pacemaker. The model predicts the experimentally observed intracellular ionic concentration of potassium, calcium and sodium. Likewise, the shapes of the simulated action potential and five membrane currents are in good agreement with experiment. We do not see any drift in the values of the concentrations in a long time simulation, and we obtain the same asymptotic values when starting from the full equilibrium situation with equal intracellular and extracellular ionic concentrations.

Action Potentials↗
PubMed2000

Optic chiasmal herniation--an under recognized complication of dopamine agonist therapy for macroprolactinoma.

The initial presentation of macroprolactinoma with visual field impairment, especially in males, is well recognized. Successful treatment with dopamine agonist therapy is characterized by a reduction in hyperprolactinaemia and often rapid and progressive resolution of the visual impairment. A small proportion of patients may subsequently develop a secondary deterioration in both their visual fields and visual acuities despite normalization of prolactin levels and tumour shrinkage. When pituitary apoplexy can be excluded this may result from traction on the optic chiasm which is pulled down into the now partially empty sella. We report a series of seven patients in whom chiasmal traction is believed to be the cause of their secondary deterioration in visual acuity occurring after dopamine agonist therapy for macroprolactinoma. The clinical history of two patients both of whom had rapid resolution of field defect with bromocriptine therapy but subsequently developed a recurrence of their bitemporal hemianopia is detailed. In both patients MRI scanning showed not only tumour involution but also marked optic chiasm herniation into the pituitary fossa. Surgical treatment was considered too risky; but on reduction of bromocriptine dosage the field defect improved in both cases; there was a modest elevation of prolactin and a degree of tumour re-expansion. The latter is believed to have released tethering of the optic chiasm and/or its vascular supply and thus obviated the need for surgery. Regular monitoring of visual fields in patients with macroprolactinoma receiving medical treatment is therefore important. Early recognition of secondary field loss due to chiasmal herniation enables correction of the visual field loss by manipulation of the medical therapy.

Adult↗
PubMed2000

What inner ear diseases cause benign paroxysmal positional vertigo?

Benign paroxysmal positional vertigo (BPPV) originating from the posterior semicircular canal (pSCC) is a common vestibular disorder that is easy to diagnose and usually easy to treat. The majority of patients with BPPV have no known inner ear disease; they have "primary" or "idiopathic" BPPV. However, a minority does have objective evidence of an inner ear disease on the same side as the BPPV and this group has "secondary" or "symptomatic" BPPV. Previous publications differ on the prevalence of secondary BPPV and about the types of inner ear diseases capable of causing it. In order to determine what proportion of patients have secondary as opposed to primary BPPV and which inner ear diseases are capable of causing secondary BPPV, we searched our database for the 10-year period from 1988 to 1997 and found a total of 2847 patients with BPPV. Of these, 81 (3%) had definite pSCC-BPPV secondary to an ipsilateral inner ear disease. Sixteen had Menière's disease, 24 had an acute unilateral peripheral vestibulopathy, 12 had a chronic unilateral peripheral vestibulopathy, 21 had chronic bilateral peripheral vestibulopathy and 8 had unilateral sensorineural hearing loss. It seems that any inner ear disease that detaches otoconia and yet does not totally destroy pSCC function can cause BPPV and that a case can be made for audiometry and caloric testing in all patients with BPPV.

Acute Disease↗
PubMed2000

The association between vascular risk factor-mediating medications and cognition and dementia diagnosis in a community-based sample of African-Americans.

OBJECTIVE: To determine the association between medications that ameliorate vascular risk factors and the prevalence of cognitive impairment and dementia in an older African-American population. DESIGN: A community-based survey to identify subjects with and without evidence of cognitive impairment and subsequent diagnostic evaluation of a stratified sample of these subjects using formal diagnostic criteria for dementia and Alzheimer's disease (AD). SETTING: Urban neighborhoods in Indianapolis, Indiana. SUBJECTS: A random sample of 2,212 African-American adults aged 65 years and older residing in 29 contiguous census tracts. MEASUREMENTS: Subjects' scores on the Community Screening Instrument for Dementia (CSID), formal diagnostic and clinical assessments for dementia, current medication use and history of medical illnesses, both self-report and, where possible, from an informant. Four outcome measures were defined by the following criteria: (1) cognitive impairment as defined by the subject's performance on the CSID cognitive scale; (2) cognitive/ functional impairment as defined by the total CSID score that included a relative's assessment of the subject's functional abilities; (3) dementia as defined by explicit diagnostic criteria; and (4) possible or probable Alzheimer's Disease as defined by explicit criteria. RESULTS: The vascular risk factor mediating medications, when analyzed together, were associated with a significantly decreased risk of diagnosis of cognitive impairment after controlling for age, education, and stroke (OR 0.73, P = .01) and also a significantly decreased risk of cognitive/functional impairment (OR 0.66, P = .02). Antihypertensive agents, excluding centrally acting sympatholytic drugs were associated with a significantly reduced risk of diagnosis of cognitive impairment (OR 0.56, P < .01) and cognitive/functional impairment (OR 0.64, P = .01). Centrally acting sympatholytic agents were associated with an increased risk of diagnosis of cognitive impairment (OR 2.24, P < .01). There was a trend toward protection from a diagnosis of AD and dementia for the vascular risk factor mediating medications and for the antihypertensive medication, but this did not reach significant levels. CONCLUSIONS: These data suggest that the use of medications to ameliorate vascular risk factors, particularly antihypertensive medication, may also be useful in reducing the risk of cognitive impairment in older subjects. However, they also suggest that physicians should be cautious in prescribing antihypertensive drugs with centrally acting sympatholytic properties to older subjects.

Aged↗
PubMed2000

Low nutrient intake contributes to adverse clinical outcomes in hospitalized elderly patients.

A prospective cohort study on hospitalized elderly patients revealed that inadequate nutrient intake during hospitalization was associated with adverse clinical outcomes and increased morbidity. Because this occurred in patients who were initially assessed as being in good health, it emphasizes the need for continuous nutritional surveillance of hospitalized elderly patients.

Aged↗
PubMed2000

Complementary therapies and the general practitioner. A survey of Perth GPs.

OBJECTIVE: The purpose of this study was to identify the knowledge, attitudes and referral patterns of general practitioners (GPs) toward 10 specific complementary therapies. METHOD: The study was a descriptive cross-sectional postal survey, conducted between July 1998 and August 1998 inclusive. A random selection of 200 male and 200 female Western Australian GPs residing in Perth and listed in the Australian Medical Association database file of registered GPs. RESULTS: The response rate was 74.8% (n = 282). Over 90% of these GPs reported having been approached by more than 30 patients seeking their advice about complementary therapies in the past nine months. The majority of these patients were women, over the age of 35 years. Ten complementary therapies were listed in the questionnaire: acupuncture, hypnosis, meditation, spinal manipulation, yoga, homeopathy, herbal medicine, naturopathy, massage and aromatherapy. Just under half (132) of the respondents had undertaken studies in at least one of the listed complementary therapies, with over 60% reporting a wish for further training. Overall, 67.8% (191) of all respondents reported they were in favour of GP referrals to complementary therapists. However, 56.1% (158) were against complementary therapies being included in rebates for private health insurance. Overall, 75.0% (211) of GPs surveyed had already formally referred a patient to one or more of the listed therapies, the most frequent of these being acupuncture, massage, meditation, hypnosis and spinal manipulation as a part of their overall medical treatment. CONCLUSION: Perth GPs have a high level of interest in complementary therapies. Government regulation and registration of complementary therapies is seen by GPs as important in order to ensure professional standards of practice. Given the high level of interest, provision of undergraduate and postgraduate education in complementary therapies could be considered. In addition, the development of clinical guidelines would be of benefit.

Adult↗