Gradient coil and radiofrequency induced heating of orthopaedic implants in MRI: influencing factors.

Patients with implanted orthopaedic devices represent a growing number of subjects undergoing magnetic resonance imaging (MRI) scans each year. MRI safety labelling is required for all implants under the EU Medical Device Regulations to ensure regulatory compliance, with each device assessed through standardised testing procedures. In this paper, we employ parametric studies to assess a range of clinically relevant factors that cause tissue heating, performing simulations with both radiofrequency (RF) and gradient coil (GC) switching fields, the latter of which is often overlooked in the literature. A series of 'worst-case' scenarios for both types of excitation field is discussed. In the case of GC fields, large volume implants and large plate areas with the field orientated perpendicular to the plane cause the highest heating levels, along with sequences with high rates of field switching. Implant heating from RF fields is driven primarily from the 'antenna effect', with thin, linear implants of resonant length resulting in the highest temperature rises. In this work, we show that simplifications may be made to the field sequence and in some cases the device geometry without significantly compromising the accuracy of the simulation results, enabling the possibility for generic estimates of the implant heating for orthopaedic device manufacturers and opportunities to simplify the safety compliance process.

Good prognosis cytogenetics in B-cell chronic lymphocytic leukemia is associated in vitro with low susceptibility to apoptosis and enhanced immunogenicity.

Chromosomal abnormalities in B-cell chronic lymphocytic leukemia (B-CLL) have been shown to correlate with prognosis. Little is known about the relationship between chromosomal abnormalities and biological behavior of B-CLL cells in vitro. The present study was designed to explore the impact of chromosomal abnormalities determined by interphase fluorescence in situ hybridization (FISH) on the in vitro survival and immunogenicity of B-CLL. Considerable heterogeneity was noted in the in vitro survival and expression of costimulatory, adhesion, and antigen-presenting molecules by B-CLL cells. Spontaneous apoptosis of B-CLL cells in vitro was significantly lower in samples with good prognosis cytogenetics when compared to samples with poor prognosis cytogenetics. In contrast, B-CLL cells from samples with good prognosis cytogenetics exhibited higher basal expression of molecules involved in costimulation, cellular adhesion, and antigen presentation, and induced significantly more T-cell proliferation in mixed lymphocyte cultures. We conclude that chromosomal aberrations of B-CLL cells correlate with the in vitro biological behavior of B-CLL. Our data indicate that good prognosis cytogenetics correlates with less spontaneous apoptosis but greater in vitro immunogenicity. These findings could have significant implications on the design of future therapeutic approaches in patients with CLL, and the likelihood of response based on cytogenetics.

Evaluation of the costs to Medicare of covering therapeutic shoes for diabetic patients.

OBJECTIVE: A three-year demonstration was fielded in three states to evaluate the cost to Medicare of a therapeutic shoes benefit for Medicare Part B beneficiaries with severe diabetic foot disease. RESEARCH DESIGN AND METHODS: Eligible Medicare beneficiaries who applied were randomly assigned to either a treatment group that received the extra therapeutic shoe coverage or a control group that received only standard Medicare coverage. This study analyzes the Medicare payments and service use of 3,428 demonstration participants in California, Florida, and New York for whom data on a 12-month follow-up period were available. These results are comparable to those for the entire sample over a variable length follow-up period that averaged 20 months but ranged from 3 months to 3 years. RESULTS: Differences between groups are not statistically significant. However, Medicare payments for all services among the treatment group were $451 (3.8%) higher than those for all services among the control group. Similarly, Medicare payments for foot-care services were $318 (14.6%) higher among beneficiaries in the treatment group, which considerably exceeded the cost of the shoe benefit ($118). CONCLUSIONS: The demonstration produced no definitive evidence that expanding Medicare Part B to cover therapeutic shoes for beneficiaries with severe diabetic foot disease would increase total Medicare costs. However, our findings indicate that the demonstration was successful at increasing therapeutic shoe ownership and was instrumental in increasing beneficiaries' use of the shoes when walking outdoors.

Simultaneous dynamic electrical and structural measurements of functional materials.

A new materials characterization system developed at the XMaS beamline, located at the European Synchrotron Radiation Facility in France, is presented. We show that this new capability allows to measure the atomic structural evolution (crystallography) of piezoelectric materials whilst simultaneously measuring the overall strain characteristics and electrical response to dynamically (ac) applied external stimuli.

Information-management technology in the Cancer Information Service.

This paper identifies the potential applications of information-management technology in the Cancer Information Service national network and describes some innovations of individual network offices in each area. New applications are explored and recommendations are made for coordinating these efforts nationally.

Trisomy 9 syndrome: report of a case with Crohn disease and review of the literature.

We report on a 6-year-old boy with mosaic trisomy 9. The patient was born at 42 weeks of gestation to a 27-year-old G1 white woman. Birth weight was 2,820 g, length 52 cm, and Apgar scores were 4 and 6 at 1 and 5 min, respectively. The infant presented with apparently low-set ears, overfolded helices, epicanthal folds, prominent nasal bridge, high-arched palate, micrognathia, bilateral dislocated hips, left genu recurvatum, and cryptorchidism. Chromosome analysis showed an unusual karyotype: 47,XY,+inv(9qh+)/47,XY,+mar. The marker chromosome was thought to be a remnant of the inv(9qh+) chromosome. The mother's karyotype was 46,XX,inv(9qh+), while the father's was 46,XY. At age 5 months, the patient developed seizures and gastroesophageal reflux. Crohn disease was diagnosed at age 2 years, although symptoms began at age 1 year. Recurrent bouts of pneumonia have occurred since the patient's birth. Severe psychomotor retardation was also noted. Trisomy 9 syndrome was first reported in 1973. Over 30 cases have been reported since then. Of these cases reports, only 5 patients were older than 1 year. Inflammatory bowel disease has been reported in association with other chromosome abnormalities, but to our knowledge, has not been reported in trisomy 9 syndrome.

Setting rates for Medicaid managed behavioral health care: lessons learned.

This paper reviews Tennessee's experience setting, monitoring, and updating capitation rates for Medicaid managed behavioral health care, and draws lessons from those experiences for other states. Our review of assumptions about four components of Tennessee's rate-setting process--data, benefit design, savings expectations, and processes for monitoring and updating rates--suggests that the initial rate established by Tennessee was inadequate, and its inadequacy resulted primarily from the way available information was used to set the rate, rather than from the method of rate setting selected. Tennessee's experiences illustrate how difficult rate setting is and illuminate several key lessons about the rate-setting process.

The evaluation of the National Long Term Care Demonstration. 7. The effect of channeling on the use of nursing homes, hospitals, and other medical services.

An analysis of the impacts of channeling on the use of hospital, nursing home, and other medical services is described. Comprehensive data on hospital and nursing home use were obtained from Medicare and Medicaid claims and provider records; other medical service use was limited to that which is reimbursed by Medicare or Medicaid. The analysis showed that the population served was not at high risk of institutionalization, and that the reductions in nursing home use among the treatment group were neither large nor, generally, statistically significant. An exception was for the small group of persons who were in a nursing home at enrollment, for whom large reductions in nursing home use were found. The population showed a very high use of hospitals and other medical services, but the channeling program had no impact on the use of these services.

Surveying consumer satisfaction to assess managed-care quality: current practices.

Growing interest in using consumer satisfaction information to enhance quality of care and promote informed consumer choice has accompanied recent expansions in managed care. This article synthesizes information about consumer satisfaction surveys conducted by managed-care plans, government and other agencies, community groups, and purchasers of care. We discuss survey content, methods, and use of consumer survey information. Differences in the use of consumer surveys preclude one instrument or methodology from meeting all needs. The effectiveness of plan-based surveys could be enhanced by increased information on alternative survey instruments and methods and new methodological studies, such as ones developing risk-adjustment methods.

Perils of pioneering: monitoring Medicaid managed care.

This article reviews Federal and State oversight of section 1115 Medicaid managed care demonstrations in Hawaii, Oklahoma, Rhode Island, and Tennessee from 1994 to 1998. Under Medicaid managed care, the Federal Government and States have had to shift their focus and resources into oversight functions that barely existed in fee-for-service (FFS) Medicaid. We find that managed care monitoring was slow to begin and not always adequate in these demonstrations. While State and Federal monitoring have improved over time, monitoring is not yet at the point of ensuring access and quality.

Economic consequences for Medicaid of human immunodeficiency virus infection.

Medicaid is currently a major source of financing for health care for those with acquired immunodeficiency syndrome (AIDS) and to a lesser extent, for those with other manifestations of human immunodeficiency virus (HIV) infection. It is likely to become even more important in the future. This article focuses on the structure of Medicaid in the context of the HIV epidemic, covering epidemiological issues, eligibility, service coverage and use, and reimbursement. A simple methodology for estimating HIV-related Medicaid costs under alternative assumptions about the future is also explained.

Do transition grants help rural hospitals?

Congress introduced the Rural Health Care Transition (RHCT) Grant Program in 1989 to assist financially troubled, small rural hospitals. This article discusses grant effects on the second cohort of hospitals to complete their 3-year grants. Although three-quarters of the grantees implemented all or most of their goals, 11 percent could not implement a viable project. Grantees added or upgraded 523 services with the help of their grants, especially outpatient and social services, most of them financially self-supporting. Except among the largest hospitals, there was no evidence that the grants improved grantee finances. Management appeared unaffected by the grants.

Corticosteroids in advanced cancer.

Despite the fact that there are only a few controlled trials demonstrating the benefits associated with the use of corticosteroids in specific situations, these agents are administered frequently to patients with advanced cancer. Corticosteroids may be used alone or as adjuvants in combination with other palliative or antineoplastic treatments. For example, corticosteroids may help prevent nausea, vomiting, and hypersensitivity reactions to treatment with chemotherapy or radiation. They are also commonly used as appetite stimulants in patients with advanced cancer. In the adjuvant setting, corticosteroids help to alleviate pain in advanced cancer patients, including specific situations such as back pain related to epidural compression. This article reviews the evidence supporting the use of corticosteroids in a broad range of situations seen in patients with advanced cancer.

Changes in primary medical care delivery, 1975-1979: findings from the physician capacity utilization surveys.

Data from two national telephone surveys of office-based primary care physicians are used to examine changes in patterns of care delivery between 1975 and 1979 in metropolitan and nonmetropolitan areas. Aspects of care delivery considered include physician availability, average physician workload, qualitative attributes of the care delivered, physicians' policies toward acceptance of new patients and fees. Physician availability relative to population increased in metropolitan areas but was unchanged in nonmetropolitan areas. The average number of office visits provided per week declined for physicians in all areas, offsetting to some extent the increase in physician availability; average weekly office visit rates declined most in nonmetropolitan areas. Most of the indicators of the qualitative attributes of care examined suggest that access to primary care physicians increased in both metropolitan and nonmetropolitan areas, though not substantially. Fees increased in real terms in all areas. Relatively fewer physicians were refusing to accept new patients in 1979 than in 1975. The possibility that specialists are providing more primary care in nonmetropolitan areas is considered as a possible explanation for the improvement in qualitative attributes of care delivered by primary care physicians in nonmetropolitan areas despite the decline in per capita office visits provided by primary care physicians in those areas.

Effects of formula change on intestinal hydrogen production and crying and fussing behavior.

To determine whether incomplete carbohydrate absorption plays a role in mediating the effects of formula change on babies' crying, breath hydrogen excretion and behavior were measured in 17 normal formula-fed infants who entered a feeding trial at 28 days of life. The trial permitted two comparisons between (1) lactose and reduced lactose soy-based formulae, and (2) the infant's usual pretrial formula and the subsequent soy-based variable-carbohydrate formulae. Reduced lactose formula was associated with a small reduction in H2 excretion (from a mean of 15 to 7 ppm, p = .07) but no difference in crying or fussing. However, compared with their usual pretrial formula, the change to soy-based variable-carbohydrate formulae was associated with a substantial and sustained reduction in H2 excretion (mean 32 to 11 ppm, p less than .03) and a modest 21% decline in fussing (90.4 to 71.5 min/24 hr, p less than .08). By 8 days after the formula change, there was a 40% decline (90.4 to 53.9 min/24 hr) in fussing. These results suggest that, although behavioral changes due to differences in carbohydrate content are unlikely in normal infants, formula changes involving protein and carbohydrate can reduce colonic gas production and may have some effect on crying. Such effects may be implicated when feeding changes occur in normal infants, but their potential role in treatment of crying problems (colic) is yet to be demonstrated.

Evaluation of bruises and areas of induration after two techniques of subcutaneous heparin injection.

The subcutaneous administration of the anticoagulant heparin sodium is a frequently performed nursing intervention. Bruising (discoloration) and induration (hardening) occur after some but not all such injections. This has implications for nursing; not only does the patient experience the physical discomfort and the psychologic impact of visible body trauma, but bruising and induration limit possible sites for future injections. Administration technique is frequently cited as a possible cause of bruising and induration. The purpose of this study was to compare two administration techniques currently being used by nurses. Variables studied included syringe size, change of needles after drawing medication into the syringe, use of an air bubble, and type of sponge (dry or alcohol) applied to the site after injection. The sample included 50 medical-surgical patients aged 23 to 88 years. Each subject received two injections by the same investigator using two different techniques. Sites were inspected and bruises and induration measured 52 hours after each injection. To compare the size of bruises and indurations, the data were analyzed by the Mann-Whitney U-Wilcoxon rank sum test, which showed a 0.003 level of significance for bruises and a 0.02 level of significance for induration. To compare the number of subjects in whom bruises and indurations developed, the data were analyzed by the chi-square test, which showed a 0.0458 level of significance for induration but only a 0.1371 level of significance for bruising.(ABSTRACT TRUNCATED AT 250 WORDS)

Web site design and development issues: the Washington State Breast and Cervical Health Program Web Site Demonstration Project.

PURPOSE/OBJECTIVES: To explore the development of a customized Web site to assist Breast and Cervical Health Program (BCHP) outreach staff in a community screening program and to evaluate the Internet knowledge and access issues and barriers of outreach staff during a two-year period using the Web site. DESIGN: Knowledge, access issues and barriers, and descriptive questionnaires. SETTINGS: Comprehensive cancer center in Seattle, WA, workshops, and presentations around the state. SAMPLE: BCHP outreach workers, screening coordinators, and almost exclusively public health nurses from regional health districts and program-contracted clinics. METHOD: Web site development was based on continuous input from sample. Detailed descriptions of computer and Internet resources and opinions about the use and usefulness of the BCHP Web site came from a 1996 evaluation and 1998 follow-up conducted using mailed and online Web questionnaires. "Hits" to the Web site were monitored monthly. MAIN RESEARCH VARIABLES: Computer and Internet resources were used along with monthly Web site traffic and opinions about the use and usefulness of the BCHP Web site in the outreach program. FINDINGS: Use of the BCHP Web site has risen steadily over two years to reach a stable plateau. User evaluations show a marked increase in the adoption of the Internet as a working tool. Users believe the Internet is becoming increasingly important to their work. More training and familiarization with the Web is needed. CONCLUSIONS: The Web is an efficient medium for improving communication and providing easy access to resources within the BCHP program. IMPLICATIONS FOR NURSING PRACTICE: Public health programs with meager resources can benefit from the relatively inexpensive use of customized and versatile Web sites.

An evaluation of criteria to designate urban health manpower shortage areas.

In the United States, federally designated health manpower shortage areas (HMSAs) have been eligible for a variety of programs intended to improve access to health services. Before 1978, HMSAs were predominantly rural. The Health Professions Educational Assistance Act of 1976 (P.L. 94-484) mandated that the criteria for designating HMSAs be revised to facilitate designation of urban areas. The most recent version of the HMSA criteria was published in 1980. This study applied the 1980 criteria to two Canadian urban areas. In general, the criteria did not succeed in distinguishing areas with relatively poorer access from those with relatively better access.

Outcome of surgical versus medical treatment of dogs with beta cell neoplasia: 39 cases (1990-1997).

OBJECTIVE: To compare outcome of surgical versus medical treatment of dogs with beta cell neoplasia. DESIGN: Retrospective study. ANIMALS: 39 dogs with clinical signs of hypoglycemia and serum glucose and insulin concentrations consistent with a diagnosis of beta cell neoplasia. PROCEDURE: Information on signalment; clinical history; physical examination findings; results of CBC, serum biochemical analyses, and urinalysis; serum glucose and insulin concentrations; results of thoracic radiography and abdominal ultrasonography; treatment and treatment complications; survival time; and cause of death were obtained from medical records. RESULTS: 26 dogs underwent exploratory celiotomy and partial pancreatectomy; 13 dogs were treated medically (i.e., dietary change and prednisone). Median survival time was significantly longer for dogs treated surgically than for dogs treated medically. Significant differences were not found in mean age, body weight, duration of clinical signs prior to diagnosis, serum glucose and insulin concentration, or results of other serum biochemical tests between dogs treated surgically and dogs treated medically; also, there was no significant correlation between any of these parameters and survival time for either group of dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that exploratory celiotomy and partial pancreatectomy are indicated once a tentative diagnosis of beta cell neoplasia is established in dogs.

Impact of the life skills training curriculum on middle school students tobacco use in Marion County, Indiana, 1997-2000.

Evaluation of school-based tobacco prevention and control programs have yielded mixed results. This study assessed the impact of the Life Skills Training curriculum on Marion County, Ind., middle school students' knowledge, attitudes, and ability to make good lifestyle decisions. From 1997 to 2000, students in grades six to eight in the study schools received the Life Skills Training curriculum. Survey data (n = 1,598) were used to compare tobacco use behavior, attitudes, and knowledge of those exposed with those not exposed to the program. Of the students surveyed, 12.5% were currently smoking. There were significantly fewer current smokers, and more students exposed to the program indicated they intended to stay smoke-free. Fewer of those participating in the program "hung out" with smokers and more said they could easily refuse a cigarette if offered one. Students completing the Life Skills Training curriculum were more knowledgeable about the health effects of smoking. Program effects were different for male and female students as well as for White and Black students.