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Biomedical subjects

K Nelson

Publications and source records attributed to K Nelson.

At least 37 records · Page 2Linked to original sources

Is food insufficiency associated with health status and health care utilization among adults with diabetes?

OBJECTIVES: Preliminary studies have shown that among adults with diabetes, food insufficiency has adverse health consequences, including hypoglycemic episodes and increased need for health care services. The purpose of this study was to determine the prevalence of food insufficiency and to describe the association of food insufficiency with health status and health care utilization in a national sample of adults with diabetes. METHODS: We analyzed data from adults with diabetes ( n =1,503) interviewed in the Third National Health and Nutrition Examination Survey. Bivariate and multivariate analyses were used to examine the relationship of food insufficiency to self-reported health status and health care utilization. RESULTS: Six percent of adults with diabetes reported food insufficiency, representing more than 568,600 persons nationally (95% confidence interval, 368,400 to 768,800). Food insufficiency was more common among those with incomes below the federal poverty level (17% vs 4%, P < or = .001). Adults with diabetes who were food insufficient were more likely to report fair or poor health status than those who were not (63% vs 43%; odds ratio, 2.2; P=.05). In a multivariate analysis, fair or poor health status was independently associated with poverty, nonwhite race, low educational achievement, and number of chronic diseases, but not with food insufficiency. Diabetic adults who were food insufficient reported more physician encounters, either in clinic or by phone, than those who were food secure (12 vs 7, P<.05). In a multivariate linear regression, food insufficiency remained independently associated with increased physician utilization among adults with diabetes. There was no association between food insufficiency and hospitalization in bivariate analysis. CONCLUSIONS: Food insufficiency is relatively common among low-income adults with diabetes and was associated with higher physician utilization.

Adult↗

Compliance in anastomoses with and without vein cuff interposition.

OBJECTIVE: to compare anastomotic compliance in end-to-side anastomoses with and without vein cuff interposition. Materials polytetrafluoroethylene graft to bovine carotid artery without (standard) and with vein interposition (Linton-patch and Miller-cuff). METHODS: zonewise compliance measurement of end-to-side anastomoses in an in-vitro circulation system. The zone most distal to the suture-line served as reference compliance. RESULTS: directly distal to the suture-line the compliance of the Linton-patch (5.6+/-1.6%/100 mmHg) and Miller-cuff anastomosis (5.2+/-1.1%/100 mmHg) more closely approached reference compliance (standard: 5.0+/-1.2, Linton-patch: 4.5+/-1.5, Miller-cuff: 4.9+/-1.0%/100 mmHg) than that of the standard anastomosis (7.9+/-3.0%/100 mmHg). The maximal compliance values of the Linton-patch (9.5+/-2.3%/100 mmHg) and Miller-cuff anastomoses (9.8+/-2.7%/100 mmHg) were significantly higher than that of the standard end-to-side anastomosis (7.9+/-3.0%/100 mmHg). However, maximal compliance was shifted from the zone directly distal to the suture line in the standard end-to-side anastomosis, to the vein cuff interposition in the Linton-patch and Miller-cuff anastomoses. CONCLUSION: the shift in maximal compliance to the wider portion of the anastomosis in the Miller-cuff and Linton-patch anastomoses may obviate reocclusion.

Anastomosis, Surgical↗

Assessment of the linear reference air kerma rate of 192Ir wires.

In this study, a procedure to test the linear reference air kerma rate of 192Ir wires using a well-type chamber is described. The method is based on a special lead insert with a 1 cm acrylic aperture that provides a differential response of the well chamber. The wire is considered divided into 1 cm parts. Using an external positioning system it is possible to place every part of the wire at the aperture position in the lead insert allowing measurement of each 1 cm making up the length of the wire. By means of a set of equations that take into account the contribution of all parts of the wire, in all possible positions, the relative linear reference air kerma rate is obtained. The estimated uncertainties of this procedure are about 2 to 3%. So, a well chamber and the specific inserts allow the measurements of total and linear reference air kerma rate for 192Ir wires.

Iridium Radioisotopes↗

Assessing pediatric anesthesia practices for volunteer medical services abroad.

BACKGROUND: Anesthetic techniques and problems in volunteer medical services abroad are different from those of either the developed countries from which volunteers originate or the host country in which they serve because of differences in patient population, facilities, and goals for elective surgery. Assessing outcomes is hampered by the transience of medical teams and the global dispersion of providers. We studied general anesthesia techniques and outcomes in a large international voluntary surgical program. METHODS: Anesthesia providers and nurses participating in care of patients undergoing reconstructive plastic and orthopedic surgery by Operation Smile over an 18-month period were asked to complete a quality assurance data record for each case. Incomplete data were supplemented by reviewing the original patient records. RESULTS: General anesthesia was used in 87.1% of the 6,037 cases reviewed. The median age was 5 yr (25th-75th percentiles: 2-9 yr). Orofacial clefts accounted for more than 80% of procedures. Halothane mask induction was performed in 85.6% of patients; 96.3% of patients had tracheal intubation, which was facilitated with a muscle relaxant in 19.3%. Respiratory complications occurred during anesthesia in 5.0% of patients and during recovery (postanesthesia care unit) in 3.3%. Arrhythmias requiring therapy occurred in 1.5%, including three patients to whom cardiopulmonary resuscitation was administered. Prolonged ventilatory support was required in seven patients. There was one death. Inadvertent extubation during surgery occurred in 38 patients. Cancellation of surgery after induction of anesthesia occurred in 25 patients. Overall, complications were more common in younger children. CONCLUSIONS: Our study showed that in this setting it is feasible to track anesthesia practice patterns and adverse perioperative events. We identified issues for further examination.

Adolescent↗

On the character of acoustic waves at the interface between hard and soft solids and liquids.

Laser ultrasonics is used to optically excite and detect acoustic waves at the interface between a liquid and a solid or coated solid. Several case studies show that this technique is feasible to investigate experimentally the theoretically predicted fundamental properties of different aspects of interface waves at liquid-solid interfaces and to characterize the elastic properties of soft solids. The theoretical prediction that the leaky Rayleigh (LR)-type root of the characteristic determinant becomes forbidden when the shear velocity of the solid lies below the bulk velocity of the liquid was experimentally confirmed. The depth profiling and nondestructive testing potential of Scholte waves was experimentally illustrated and explained by the properties of the wave displacement profile.

Journal Article↗

Mycobacterium tuberculosis disease in Somali immigrants in Minnesota.

STUDY OBJECTIVE: To characterize pulmonary and extrapulmonary Mycobacterium tuberculosis cases in the Somali community in Minnesota. DESIGN: Retrospective chart review of active tuberculosis cases in Somalis reported to the Minnesota Department of Health between January 1993 and June 1998. PATIENTS: Ethnic Somalis in the state of Minnesota with M tuberculosis diagnosed by positive culture or radiographic findings consistent with tuberculosis and clinical improvement when treated with antituberculous drugs. RESULTS: Eighty-two Somali patients were diagnosed with tuberculosis during the study period. Extrapulmonary disease (typically lymphadenopathy) was present in 46% (n = 38). The 1997 incidence of tuberculosis in Minnesota's Somali population was estimated at 170 cases per 100,000 population compared with a national incidence of 20.5 per 100,000 among African Americans and 2.5 per 100,000 among whites. Ninety percent of Somali patients were < 40 years of age; 63% were diagnosed within 1 year of immigration, and > 90% had positive results with the purified protein derivative skin test. M tuberculosis was confirmed in 24 of 25 isolates from extrapulmonary cases. Multidrug resistance was present in 3.4%, and only two patients had AIDS. CONCLUSIONS: Somalis have a high incidence of active disease, with frequent extrapulmonary involvement in the absence of AIDS, clinical presentation shortly after immigration, and infrequent infection with resistant organisms. Health-care providers should maintain an increased awareness for tuberculosis when evaluating Somali immigrants.

Adult↗

Pediatric generalists and subspecialists: determinants of career satisfaction.

OBJECTIVES: To evaluate the work life and job satisfaction of pediatric generalists and subspecialists in comparison to each other and to a group of general internists and internal medicine subspecialists. METHODS: Data were collected by survey of a national sample of 5704 general pediatricians, subspecialty pediatricians, general internists, internal medicine subspecialists, and family physicians who were selected randomly from the American Medical Association Masterfile using stratified sampling with disproportionate weighting to ensure ethnic diversity and representation of high managed care areas. Surveys were mailed up to 4 times and contained 150 items that reflected 10 facets of physician job satisfaction as well as an assessment of individual and practice demographic information. This study reports data from all groups except for family medicine. RESULTS: The adjusted response rate was 58% for general pediatricians (n = 590), 67% for specialty pediatricians (n = 345), and 52% (n = 1823) for the entire pool. In comparison with general internists, general pediatricians were more likely to be female (44% vs 24%); to work part time (20% vs 12%); to have lower annual income ($125 679 vs $143 875); and to report significantly higher levels of job, career, and specialty satisfaction on a 5-point scale (3.81 vs 3.52, 3.80 vs 3.55, and 3.76 vs 3.17 respectively). In comparison with internal medicine subspecialists, pediatric subspecialists were more likely to be female (42% vs 22%); to work in academically affiliated settings (35% vs 17%); to have lower incomes ($156 284 vs $192 006); to receive significantly less time for a complete history and physical examination (39 minutes vs 51 minutes); and to report similar levels of job, career, and specialty satisfaction (3.69 vs 3.71, 3.74 vs 3.78, and 3.60 vs 3.47 respectively). Of all 4 physician groups, general pediatricians worked the fewest hours (50/week), spent the greatest percentage of time in the office and the lowest percentage in the hospital (58% and 16%, respectively), saw the lowest percentage of patients with complex medical and complex psychosocial problems (15% and 17%, respectively), and were the least likely to endorse symptoms of burnout or job stress (13% and 18%, respectively). In comparison, pediatric subspecialists worked longer hours (59/week), spent the lowest percentage of time in the office and the greatest percentage of time in the hospital (22% and 44%, respectively), saw a much higher percentage of patients with complex medical and complex psychosocial problems (46% and 25%, respectively), and reported significantly higher levels of burnout and job stress (23% and 26%, respectively). CONCLUSIONS: Despite lower incomes, general pediatricians reported the highest levels of satisfaction and the least job stress of all 4 physician groups, whereas pediatric subspecialists reported levels of stress and burnout that raise significant concerns for the workforce of pediatric subspecialists of the future. Initiatives that improve clinical workload, balance inpatient and outpatient hours, and increase personal time of pediatric subspecialists should be considered.

Burnout, Professional↗

A kinetic and kinematic analysis of the Harai-goshi judo technique.

The purpose of this study was to analyze and compare the kinetic and kinematic characteristics of the throwing technique, Harai-goshi of novice and advanced judo competitors. A heterogeneous group of 28 male and female judo competitors participated in this study. Each subject was required to perform three successful trials. Kinetic and kinematic data were collected by utilizing the Kistler Instrument Corporation Multicomponent Force Measuring Platform System and the Peak Technologies Motion Video Analysis System. Data were collected in order to quantitatively and qualitatively analyze the horizontal and vertical forces of the support leg, and the horizontal and vertical velocities of the sweeping leg during execution of the throwing technique, Harai-goshi (hip sweep). The study revealed a significant difference in horizontal force application, between novice and advanced judo competitors. In addition, we found numerous significant relationships among mean horizontal ground reaction force application and horizontal leg sweep velocity in 19 of the 28 participants when analyzed individually. The results suggest (1) leg sweep velocity is a function of ground reaction force application; and (2) horizontal leg sweep velocity plays a primary role in good technical execution of the Harai-goshi throw.

Adolescent↗

Forensic mitochondrial DNA analysis: two years of commercial casework experience in the United States.

AIM: To describe mitochondrial DNA (mtDNA) forensic casework experience in a commercial laboratory in the United States. METHODS: Frequency statistics were kept for two years on all aspects of mtDNA forensic cases, including types of clientele, types of samples, levels of sample success and failure, site heteroplasmy, length heteroplasmy, contamination, rates of failures to exclude, and match statistics using a mtDNA sequence database. RESULTS: Low sample failure rate was observed, especially since an "ancient DNA" approach was used for samples with degraded DNA. Levels of contamination were low, and the observed site and length heteroplasmy did not confound the interpretation of results. The data collected from mtDNA haplotypes developed in casework showed extremely high diversity of haplotypes consistent with other formally developed databases. CONCLUSIONS: MtDNA forensic analysis in the private sector was successfully applied to many different types of samples overall, with minimal rates of complication due to sample handling challenges (degraded DNA, minimal samples, contamination) and sequence-specific phenomena (site and length heteroplasmy).

Blood Chemical Analysis↗

The effect of gender on age-related blood pressure changes and the prevalence of isolated systolic hypertension among older adults: data from NHANES III.

OBJECTIVE: To examine gender differences in age-related blood pressure changes and the prevalence of isolated systolic hypertension. DESIGN: Third National Health and Nutrition Examination Survey, 1988-1994. SETTING: 89 mobile examination centers and household questionnaire. PARTICIPANTS: 6635 men and 7189 women over the age of 18 years who were not under treatment for high blood pressure. MAIN OUTCOME MEASURES: Levels of systolic blood pressure, diastolic blood pressure, and pulse pressure by age and gender; prevalence of isolated systolic hypertension (ISH). RESULTS: Systolic blood pressures (SBP) and pulse pressures (PP) were higher in males than in females among adults less than 45 years old. After age 45, SBP and PP were higher in females. Diastolic blood pressures were lower among adult females across all age categories. The prevalence of stages 1 and 2/3 ISH were higher among females after age 44 years. The magnitude of the gender differences in the prevalence of ISH was also age-dependent. CONCLUSIONS: ISH was higher in elderly women than men. These age-related blood pressure changes may account in part for the higher cardiovascular mortality reported among elderly females compared with elderly males and should be considered an important target for cardiovascular preventive strategy, particularly in elderly females.

Adolescent↗

The role of physical proximity in nosocomial diarrhea.

To examine physical proximity as a risk factor for the nosocomial acquisition of Clostridium difficile-associated diarrhea (CDAD) and of antibiotic-associated diarrhea (AAD), we assessed a retrospective cohort of 2859 patients admitted to a community hospital from 1 March 1987 through 31 August 1987. Of these patients, 68 had nosocomial CDAD and 54 had nosocomial AAD. In multivariate analysis, physical proximity to a patient with CDAD (relative risk [RR], 1.86; 95% confidence interval [CI], 1.06-3.28), exposure to clindamycin (RR, 4.22; 95% CI, 2.11-8.45), and the number of antibiotics taken (RR, 1.49; 95% CI, 1.23-1.81) were significant. For patients with nosocomial AAD, exposure to a roommate with AAD (RR, 3.94; 95% CI, 1. 27-12.24), a stay in an intensive care unit or cardiac care unit (RR, 1.93; 95% CI, 1.05-3.53), and the number of antibiotics taken (RR, 2.01; 95% CI, 1.67-2.40) were significant risk factors. Physical proximity may be an independent risk factor for acquisition of nosocomial CDAD and AAD.

Adult↗

Phase I/II trial of neutrophil transfusions from donors stimulated with G-CSF and dexamethasone for treatment of patients with infections in hematopoietic stem cell transplantation.

We examined the feasibility of a community blood bank granulocyte transfusion program utilizing community donors stimulated with a single-dose regimen of subcutaneous granulocyte colony-stimulating factor (G-CSF) plus oral dexamethasone. The recipients of these transfusions were neutropenic stem cell transplantation patients with severe bacterial or fungal infection. Nineteen patients received 165 transfusions (mean 8.6 transfusions/patient, range 1-25). Community donors provided 94% of the transfusions; relatives accounted for only 6% of the transfusions. Sixty percent of the community donors initially contacted agreed to participate, and 98% of these individuals indicated willingness to participate again. Transfusion of 81.9 +/- 2.3 x 10(9) neutrophils (mean +/- SD) resulted in a mean 1-hour posttransfusion neutrophil increment of 2. 6 +/- 2.6 x 10(3)/microL and restored the peripheral neutrophil count to the normal range in 17 of the 19 patients. The buccal neutrophil response, a measure of the capacity of neutrophils to migrate to tissue sites in vivo, was restored to normal in most patients following the transfusion. Chills, fever, and arterial oxygen desaturation of >/= 3% occurred in 7% of the transfusions, but these changes were not sufficient to limit therapy. Infection resolved in 8 of 11 patients with invasive bacterial infections or candidemia. These studies indicate that transfusion of neutrophils from donors stimulated with G-CSF plus dexamethasone can restore a severely neutropenic patient's blood neutrophil supply and neutrophil inflammation response. Further studies are needed to evaluate the clinical efficacy of this therapy.

Administration, Oral↗

Chimeric peptides of statherin and osteopontin that bind hydroxyapatite and mediate cell adhesion.

Extracellular matrix proteins play key roles in controlling the activities of osteoblasts and osteoclasts in bone remodeling. These bone-specific extracellular matrix proteins contain amino acid sequences that mediate cell adhesion, and many of the bone-specific matrix proteins also contain acidic domains that interact with the mineral surface and may orient the signaling domains. Here we report a fusion peptide design that is based on this natural approach for the display of signaling peptide sequences at biomineral surfaces. Salivary statherin contains a 15-amino acid hydroxyapatite binding domain (N15) that is loosely helical in solution. To test whether N15 can serve to orient active peptide sequences on hydroxyapatite, the RGD and flanking residues from osteopontin were fused to the C terminus. The fusion peptides bound tightly to hydroxyapatite, and the N15-PGRGDS peptide mediated the dose-dependent adhesion of Moalpha(v) melanoma cells when immobilized on the hydroxyapatite surface. Experiments with an integrin-sorted Moalpha(v) subpopulation demonstrated that the alpha(v)beta(3) integrin was the primary receptor target for the fusion peptide. Solid state NMR experiments showed that the RGD portion of the hydrated fusion peptide is highly dynamic on the hydroxyapatite surface. This fusion peptide framework may thus provide a straightforward design for immobilizing bioactive sequences on hydroxyapatite for biomaterials, tissue engineering, and vaccine applications.

Adsorption↗

Mycophenolate mofetil decreases endothelial prostaglandin E2 in response to allogeneic T cells or cytokines.

BACKGROUND: Prostaglandin E2 (PGE2) is a powerful endogenous immune suppressant and interferes with various T-cell functions. However, it is not known in detail whether immunosuppressive drugs influence the PGE2-driven immune response in transplant patients. Therefore, we investigated the effect of several immunosuppressive compounds, in particular the novel drug mycophenolate mofetil (MMF), on endothelial PGE2 release. METHODS: Endothelial cells (HUVEC) were activated by either allogeneic CD4+ or CD8+ T cells, or by the cytokines interleukin-1 or gamma-interferon. Using an enzyme-linked immunosorbent assay, we analyzed PGE2 release of the activated HWEC in the presence of MMF, cyclosporine, or tacrolimus. As verapamil and mibefradil also possess immunosuppressive properties, they were included in the study as well. RESULTS: Activation of HUVEC with interleukin-1 or T cells resulted in a drastic accumulation of PGE2 in the supernatant. Cyclosporine or tacrolimus had no effect on PGE2 release. However, Ca2+ channel blockers, when applied at higher dosages, caused a significant increase in PGE2. Interestingly, MMF strongly diminished the PGE2 level in the cell culture supernatant in a concentration-dependent manner. CONCLUSION: The results demonstrate an inhibitory effect of MMF on PGE2 production, which may lower the benefits of the PGE2-triggered immune response after organ transplantation.

Cells, Cultured↗

WD40 repeat proteins striatin and S/G(2) nuclear autoantigen are members of a novel family of calmodulin-binding proteins that associate with protein phosphatase 2A.

Protein phosphatase 2A (PP2A) is a multifunctional serine/threonine phosphatase that is critical to many cellular processes including development, neuronal signaling, cell cycle regulation, and viral transformation. PP2A has been implicated in Ca(2+)-dependent signaling pathways, but how PP2A is targeted to these pathways is not understood. We have identified two calmodulin (CaM)-binding proteins that form stable complexes with the PP2A A/C heterodimer and may represent a novel family of PP2A B-type subunits. These two proteins, striatin and S/G(2) nuclear autoantigen (SG2NA), are highly related WD40 repeat proteins of previously unknown function and distinct subcellular localizations. Striatin has been reported to associate with the post-synaptic densities of neurons, whereas SG2NA has been reported to be a nuclear protein expressed primarily during the S and G(2) phases of the cell cycle. We show that SG2NA, like striatin, binds to CaM in a Ca(2+)-dependent manner. In addition to CaM and PP2A, several unidentified proteins stably associate with the striatin-PP2A and SG2NA-PP2A complexes. Thus, one mechanism of targeting and organizing PP2A with components of Ca(2+)-dependent signaling pathways may be through the molecular scaffolding proteins striatin and SG2NA.

3T3 Cells↗

Development of a clinical fellowship program in palliative medicine.

There has been growing interest in the United States in postgraduate training in palliative medicine. In order for this to proceed in an organized fashion, educational standards need to be developed. We must define what our knowledge base is and what we require of a specialty-trained individual. This article reports the development of the first fellowship program in the United States, with the goal of encouraging further discussion and ultimately obtaining specialty recognition.

Education, Medical, Graduate↗