PubMed Health⌕ Search

Biomedical subjects

E Stone

Publications and source records attributed to E Stone.

At least 19 recordsLinked to original sources
PubMed2001

Surface-induced dissociation on a MALDI-ion mobility-orthogonal time-of-flight mass spectrometer: sequencing peptides from an "in-solution" protein digest.

Peptide sequencing by surface-induced dissociation (SID) on a MALDI-ion mobility-orthogonal TOF mass spectrometer is demonstrated. SID of approximately 100-fmol amounts of model peptides HLGLAR (m/z 666.8), gramicidin S (m/z 1142.5), and bovine insulin b chain (m/z 3495.5) was accomplished using hydrocarbon-coated gold grids and approximately 20-eV collision energies. The current version of the instrument achieves a mobility resolution of approximately 20 and TOF mass resolution better than 200. Peptide sequences of four peptides from a tryptic digest of cytochrome c (approximately 1 pmol deposited) were obtained. The advantage of IM-SID-o-TOF-MS is that a single experiment can be used to simultaneously measure the molecular weights of the tryptic peptide fragments (e.g., peptide mass mapping) and partial sequence analysis, (e.g., real-time tandem mass spectrometry.)

Amino Acid Sequence↗
PubMed2001

Patterns of physical activity among American Indian children: an assessment of barriers and support.

Estimates indicate that 10% to 50% of American Indian and non-Indian children in the U.S. are obese, defined as a body mass index > or = 95th percentile of the NHANES II reference data. Pathways is a two-phase, multi-site study to develop and test a school-based obesity prevention program in American Indian schoolchildren in grades three through five. During Phase I feasibility prior to initiation of the Pathways trial, data were collected related to physical activity patterns, and the supports of, and barriers to, physical activity. Nine schools from communities representing six different tribal groups participated in this study. Multiple measures were used for data collection including direct observation, paired child interviews, and in-depth interviews and focus groups with adults. Students completed the self-administered Knowledge, Attitudes, and Behaviors (KAB) survey, and a Physical Activity Questionnaire (PAQ). Barriers to physical activity at schools included a lack of facilities, equipment, and trained staff persons for PE. Adults were not consistently active with their children, but they were highly supportive of their children's activity level. Children reported a strong enjoyment of physical activity and strong peer support to be physically active. Weather conditions, safety concerns, and homework/chores were common barriers to physical activity reported by children and adult caregivers. The information was used to design culturally and age-appropriate, practical interventions including the five physical activity programs for schoolchildren in the Pathways study.

Activities of Daily Living↗
PubMed2001

Genomic organization and mutation analysis of the gene encoding lecithin retinol acyltransferase in human retinal pigment epithelium.

PURPOSE: To determine the structure of the human lecithin retinol acyltransferase (LRAT) gene, map its chromosomal localization, and screen for mutations in humans with various hereditary retinal degenerations. METHODS: Using DNA probes specific for LRAT, a bacterial artificial chromosome (BAC) clone containing the LRAT gene was isolated, subcloned into DNA fragments and relevant subclones characterized by sequencing. Exon-intron junctions were determined by comparison with the cDNA sequence previously published. Southern blot analysis was performed on human genomic DNA samples digested with several restriction enzymes. Fluorescence in situ hybridization (FISH) analysis of normal metaphase chromosomes derived from phytohemagglutinin (PHA) stimulated peripheral blood lymphocytes and radiation hybrid mapping were used for localization of the LRAT gene. Single-strand conformation polymorphism analysis (SSCP) was used to screen for potential mutations in patients with age-related macular degeneration, Leber congenital amaurosis, retinitis pigmentosa, and cone-rod dystrophy. RESULTS: The human LRAT gene is organized into three exons of 219, 541, and 2058 bp and two introns of 103 and 4117 bp. Southern blot analysis of digested genomic DNA revealed a single band, suggesting a single copy of the LRAT gene. The human LRAT gene was localized to chromosome 4q31.2, a locus having no previous association with human eye disease. Additionally, the bovine LRAT homologue sequence was deduced and a general LRAT protein topology is suggested. No polymorphisms that segregated with retinal disease phenotypes were identified in 374 unrelated probands. CONCLUSIONS: The organization of the LRAT gene, based on cDNA clones derived from the retinal pigment epithelium (RPE) has been determined. Its structure is less complex than other acyltransferases such as lecithin cholesterol acyltransferase (LCAT) and acyl CoA acyltransferase (ACAT). The absence of polymorphisms in the probands examined suggests a very low mutation level in the LRAT gene from the diseases analyzed.

Acyltransferases↗
PubMed2000

Patient delay in seeking care for heart attack symptoms: findings from focus groups conducted in five U.S. regions.

BACKGROUND: Patient delay in seeking health care for heart attack symptoms is a continuuing problem in the United States. METHODS: Investigators conducted focus groups (N = 34; 207 participants) in major U.S. regions (NE, NW, SE, SW, MW) as formative evaluation to develop a multi-center randomized community trial (the REACT Project). Target groups included adults with previous heart attacks, those at higher risk for heart attack, and bystanders to heart attacks. There were also subgroups reflecting gender and ethnicity (African-American, Hispanic-American, White). FINDINGS: Patients, bystanders, and those at higher risk expected heart attack symptoms to present as often portrayed in the movies, that is, as sharp, crushing chest pain rather than the more common onset of initially ambiguous but gradually increasing discomfort. Patients and those at higher risk also unrealistically judge their personal risk as low, understand little about the benefits of rapid action, are generally unaware of the benefits of using EMS/9-1-1 over alternative transport, and appear to need the "permission" of health care providers or family to act. Moreover, participants reported rarely discussing heart attack symptoms and appropriate responses in advance with health care providers, spouses, or family members. Women often described heart attack as a "male problem," an important aspect of their underestimation of personal risk. African-American participants were more likely to describe negative feelings about EMS/9-1-1, particularly whether they would be transported to their hospital of choice. CONCLUSIONS: Interventions to reduce patient delay need to address expectations about heart attack symptoms, educate about benefits and appropriate actions, and provide legitimacy for taking specific health care-seeking actions. In addition, strategy development must emphasize the role of health care providers in legitimizing the need and importance of taking rapid action in the first place.

Adaptation, Psychological↗
PubMed2000

The emergency department experience of chest pain patients and their intention to delay care seeking for acute myocardial infarction.

This study investigated how patients' emergency department experience was related to their intention to delay action in response to future symptoms of acute myocardial infarction. A sample of 426 persons admitted to the emergency department with a chief complaint of chest pain and released from the emergency department were contacted by telephone. Patients were queried about their affective response to the emergency department experience, their satisfaction with emergency department staff communication, their intention to delay prompt action for acute myocardial infarction symptoms in the future, the influence of others in the decision to seek care, and medical and demographic status. The results of a mixed model linear regression analysis showed that the less education patients had (p = 0.007), the less sure they felt that going to the emergency department had been "the right thing to do" (p = 0.004), and the greater the degree of embarrassment (p = 0.0001), the greater was the intention to delay action for future symptoms of acute myocardial infarction. The results also showed that those patients who were prompted by health professionals to go to the emergency department were less likely to report intentions to delay for future symptoms (p = 0.036). It is important that emergency department staff reassure chest pain patients who are sent home that they did the right thing by coming to the emergency department for their symptoms. Providers need to be particularly sensitive to feelings of embarrassment.

Chest Pain↗
PubMed2000

Persistent, progressive hypophosphataemia after voluntary hyperventilation.

Hyperventilation (HV) and respiratory alkalosis are associated with hypophosphataemia, although the extent and duration of HV required to produce changes in serum phosphate levels are not known. We sought to characterize the effects of HV, with or without dextrose loading, on serum phosphate levels and other biochemical parameters. HV was monitored by controlling the end-tidal partial pressure of carbon dioxide (PETCO(2)). The effect of dextrose was studied because infusion of a glucose load is known to promote a fall in serum phosphate via stimulation of glycolysis. Eight healthy volunteers were enrolled in four study protocols: (1) HV for 20 min to a PETCO(2) of 25-30 mmHg (mild); (2) HV for 20 min to a PETCO(2) of 15-20 mmHg (severe); (3) mild HV with intravenous dextrose loading, and (4) dextrose loading alone. Periodic measurements of serum phosphate, venous pH, serum 2,3-diphosphoglycerate (2,3-DPG) and other parameters were made. Serum phosphate fell during HV and continued to decline after cessation of HV. Dextrose loading alone caused a fall in serum phosphate that continued for at least 30 min after cessation of the infusion (P<0.0002). HV combined with dextrose resulted in a greater decline in serum phosphate than either variable alone (P=0.003). The maximal decline in serum phosphate occurred in severe HV, with a mean decrease of 0.38 mmol/l at 20 min after cessation of HV (P<0.0001). Serum phosphate was still significantly lowered compared with baseline at 90 min after cessation of HV (P=0.001). Other significant changes seen with HV included a decrease in serum glucose (P<0.01), a decrease in serum potassium (P<0.05) and an increase in venous pH (P<0.007). Serum 2, 3-DPG levels did not change significantly in any study protocol. Thus relatively mild acute HV produces significant changes in serum phosphate. In both mild and severe HV this effect is progressive after cessation of HV. This phenomenon has not been shown before, and may have significant clinical implications.

Adult↗
PubMed1999

Correlates of condom failure in a sexually active cohort of men who have sex with men.

Condom failure (slippage or breakage) has been shown to be associated with HIV seroconversion among men who have sex with men (MSM), but predictors of failure have been poorly elucidated. Of 2592 HIV-seronegative MSM participants in the HIV Network for Prevention Trials (HIVNET) multisite Vaccine Preparedness Study who reported condom use for anal sex in the 6 months before enrollment, condom failure was reported by 16.6%, with failure rates of 2.1/100 episodes of condom usage (2.5 failures/100 episodes for receptive anal sex and 1.9/100 episodes for insertive anal sex). In separate multivariate models evaluating predictors of condom failure reported by the insertive and receptive partners, more frequent condom use was associated with a decreased per-condom failure rate and amphetamine and heavy alcohol use with increased rates in both models. Being employed, having private medical insurance, and using lubricants for >80% of anal sex acts were significantly associated with decreased failure rates in the insertive model. Safer sex counseling should particularly target men of lower socioeconomic status, promote proper and consistent use of condoms with appropriate lubricants, and address the impact of drug use, especially amphetamines and alcohol, on condom failure.

Adult↗
PubMed1999

Physician education and report cards: do they make the grade? results from a randomized controlled trial.

PURPOSE: We sought to determine whether tailored educational interventions call improve the quality of care, as measured by the provision of preventive care services recommended by the US Preventive Services Task Force, as well as lead to better patient satisfaction. SUBJECT AND METHODS: We performed a randomized controlled study among 41 primary care physicians who cared for 1,810 randomly selected patients aged 65 to 75 years old at Kaiser Permanente Woodland Hills, a group-model health maintenance organization in southern California. All physicians received ongoing education. Physicians randomly assigned to the comprehensive intervention group also received peer-comparison feedback and academic detailing. Baseline and postintervention (2 to 2.5 years later) surveys examining the provision of preventive care and patient satisfaction were performed and medical records were reviewed. RESULTS: Based on the results of patient surveys, there were significant improvements over time in the provision of preventive care in both the education and the comprehensive intervention groups for influenza immunization (79% versus 89%, P <0.01, and 80% versus 91%, P <0.01), pneumococcal immunization (42% versus 73%, P < 0.01 and 34% versus 73%, P < 0.01), and tetanus immunization (64% versus 72%, P <0.01, and 59% versus 79%, P <0.01). Mammography (90% versus 80%, P <0.01) and clinical breast examination (85% versus 79%, P <0.05) scores worsened in the education only group but not in the comprehensive intervention group. However, there were few differences in rates of preventive services between the groups at the end of the study, and the improvements in preventive care were not confirmed by medical record review. Patient satisfaction scores improved significantly in the comprehensive intervention group (by 0.06 points on a 1 to 5 scale, P = 0.02) but not in the education only group (by 0.02 points, P = 0.42); however, the improvement was not significantly greater in the comprehensive intervention group (P = 0.20). CONCLUSION: A physician-targeted approach of education, peer-comparison feedback, and academic detailing has modest effects on patient satisfaction and possibly on the offering of selected preventive care services. The lack of agreement between patient reports and medical records review raises concerns about current methods of ascertaining compliance with guidelines for preventive care.

Aged↗
PubMed1999

Zonation of acetate labeling across the liver: implications for studies of lipogenesis by MIDA.

Measurement of fractional lipogenesis by mass isotopomer distribution analysis (MIDA) of fatty acids or cholesterol labeled from [(13)C]acetate assumes constant enrichment of lipogenic acetyl-CoA in all hepatocytes. This would not be the case if uptake and release of acetate by the liver resulted in transhepatic gradients of acetyl-CoA enrichment. Conscious dogs, prefitted with transhepatic catheters, were infused with glucose and [1, 2-(13)C(2)]acetate. Stable concentrations and enrichments of acetate were measured in artery (17 microM, 36%), portal vein (61 microM, 5. 4%), and hepatic vein (17 microM, 1.0%) and were computed for mixed blood entering the liver (53 microM, 7.4%). We also measured balances of propionate and butyrate across gut and liver. All gut release of propionate and butyrate is taken up by the liver. The threefold decrease in acetate concentration and the sevenfold decrease in acetate enrichment across the liver strongly suggest that the enrichment of lipogenic acetyl-CoA decreases across the liver. Thus fractional hepatic lipogenesis measured in vivo by MIDA may be underestimated.

Acetates↗
PubMed1998

Physicians' changing attitudes toward guidelines.

The objective of the study was to measure the change in physicians' attitudes toward preventive care guidelines over a 2-year period. The study was conducted at a Southern California managed care medical group that was experiencing intense price competition. We analyzed individualized survey responses of 62 HMO primary care physicians over the study period. We found that physicians increasingly believed that clinical guidelines were being used for cost containment (first survey 71% vs second survey 92%, p < .005) and less for quality improvement (first survey 85% vs second survey 67%, p < .008) over time. These findings may create a barrier to physicians' adoption of practice guidelines.

Adult↗
PubMed1998

Pituitary adenoma producing growth hormone and adrenocorticotropin: a histological, immunocytochemical, electron microscopic, and in situ hybridization study. Case report.

The authors report on the morphological features of a pituitary adenoma that produced growth hormone (GH) and adrenocorticotropic hormone (ACTH). This hormone combination produced by a single adenoma is extremely rare; a review of the available literature showed that only one previous case has been published. The tumor, which was removed from a 62-year-old man with acromegaly, was studied by histological and immunocytochemical analyses, transmission electron microscopy, immunoelectron microscopy, and in situ hybridization. When the authors used light microscopy, the tumor appeared to be a bimorphous mixed pituitary adenoma composed of two separate cell types: one cell population synthesized GH and the other ACTH. The cytogenesis of pituitary adenomas that produce more than one hormone is obscure. It may be that two separate cells--one somatotroph and one corticotroph--transformed into neoplastic cells, or that the adenoma arose in a common stem cell that differentiated into two separate cell types. In this case immunoelectron microscopy conclusively demonstrated ACTH in the secretory granules of several somatotrophs. This was associated with a change in the morphological characteristics of secretory granules. Thus it is possible that the tumor was originally a somatotropic adenoma that began to produce ACTH as a result of mutations that occurred during tumor progression.

Acromegaly↗
PubMed1998

[Mutational screening of peripherin/RDS genes, rhodopsin and ROM-1 in 69 index cases with retinitis pigmentosa and other retinal dystrophies].

PURPOSE: Phenotypic, genetic and molecular characterization of 69 index patients with retinitis pigmentosa (RP) and various inherited retinal diseases. PATIENTS AND METHOD: patients went through complete ocular examination and blood samples were drawn for mutational screening of three candidate genes: rhodopsin (RHO), peripherin/RDS, and ROM-1. RESULTS: the most frequent type of RP among our population was the autosomal dominant (43.6%). Three RHO mutations were found among the RP patients. A RDS mutation was detected in three unrelated families segregating dominant macular dystrophy. DISCUSSION AND CONCLUSIONS: 18% of the autosomal dominant RP patients presented a RHO mutation; RDS R172W mutation was present in 25% of the dominant macular dystrophies.

Adult↗
PubMed1997

Effect of unilateral tympanotomy on auditory induced c-fos expression in cochlear nuclei.

The immediate early gene, c-fos, signals expression of target genes. Three natural occurring physiological entities: (1) learning, (2) plasticity, and (3) stress are proposed to use c-fos gene expression to signal molecular changes in neurons. The objective of this study was to determine whether c-fos expression is predominately activated by stress or by novel events associated with learning and plasticity. The approach was to quantitate the number of neurons in cochlear nuclei which express Fos protein following short-term novel sound stimuli together with either uni- or bilateral tympanotomy so as to differentiate novel sound stimuli from stress activation. The results show that routinely experienced sounds do not elicit c-fos expression in medullary cochlear nuclei, but novel sounds produced a 25-fold increase in the number of active cells. Following unilateral tympanotomy with novel sound stimulation, only a small number of cells were activated, ipsilaterally, (partially deafened side) while contralaterally, there was a 30-fold increase. After normalization of the data for control values, the data clearly indicate that novelty of sound stimuli induce c-fos gene expression. Furthermore, bilateral tympanotomy (bilateral partial deafening) with sound stimulation activated both sides by 20-fold, indicating that the c-fos response followed the sound stimulation. The data allow us to conclude that stress generates only a small contribution to c-fos gene expression while novel stimuli are potent signals, strongly implicating c-fos in novelty induced adaptation processes involved in learning and plasticity.

Acoustic Stimulation↗
PubMed1997

Mutations in the cone-rod homeobox gene are associated with the cone-rod dystrophy photoreceptor degeneration.

Crx is a novel paired-like homeodomain protein that is expressed predominantly in retinal photoreceptors and pinealocytes. Its gene has been mapped to chromosome 19q13.3, the site of a disease locus for autosomal dominant cone-rod dystrophy (CORDII). Analysis of the proband from a family with autosomal dominant CORD revealed an Arg41Trp substitution in the third residue of the CRX homeodomain. The sequence change cosegregated with the disease phenotype and was not detected in 247 normal controls. Recombinant CRX homeodomain containing the Arg41Trp substitution showed decreased DNA binding activity. Analysis of another 169 CORD probands identified three additional CRX sequence variations (Arg41Gln, Val242Met, and a 4 bp deletion in codons 196/7) that were not found among the controls. This data suggests that mutations in the CRX gene are associated with photoreceptor degeneration and that the Crx protein is necessary for the maintenance of normal cone and rod function.

Adult↗
PubMed1997

Physical activity in a multiethnic population of third graders in four states.

OBJECTIVES: This research assessed the amount of daily physical activity in a multiethnic sample of US third-grade students. METHODS: Physical activity interviews were conducted with 2410 third graders from 96 schools in four states. Blood pressure, cholesterol, body mass index, timed run for distance, physical-activity self-efficacy, and perceived support for physical activity were also assessed. RESULTS: Students reported a daily average of 89.9 minutes of moderate to vigorous physical activity, 34.7 minutes of vigorous activity, and 120.4 minutes of sedentary behavior; however, 36.6% obtained less than 60 minutes of moderate to vigorous physical activity daily, and 12.8% reported less than 30 minutes. Boys reported more physical and sedentary activity than girls; White children reported more activity than Black or Hispanic children; California children reported the most activity and Louisiana children the least. Geographic location, male gender, lower cholesterol, higher perceived efficacy in physical activity, and higher social support were associated with more physical activity. CONCLUSIONS: Average reported activity met the Year 2000 objectives; however, many students reported less than recommended amounts of activity. These findings support the need for health promotion programs that increase the number of physically active children.

Analysis of Variance↗