Biomedical subjects

I B Wilson

Publications and source records attributed to I B Wilson.

At least 19 recordsLinked to original sources

PubMed2002

Changes in lean body mass and total body weight are weakly associated with physical functioning in patients with HIV infection.

CONTEXT: For clinicians managing weight loss in patients with HIV, it would be useful to understand how changes in lean body mass (LBM) effect physical functioning, and whether LBM is more strongly related to physical functioning than total body weight (TBW). OBJECTIVE: To determine the relationship of changes in LBM and changes in total body weight (TBW) to changes in self-reported physical functioning in men and women with HIV infection. METHODS: Study design was longitudinal analysis of 1474 patient-intervals (each interval was approximately 6 months long) in 486 persons. Patients were participants in Nutrition for Healthy Living, a cohort study of HIV positive persons in Massachusetts and Rhode Island. The main outcome measure was change in self-reported physical functioning. RESULTS: Of the 1,474 intervals, 1,165 were contributed by men and 309 by women. The mean CD4 count for the 1,474 intervals was 383 cells/ micro L. In men, 5 kg changes in LBM and TBW were associated with 2.2 (95% confidence interval, 0.9, 3.4, P= 0.001) and 2.6 (95% confidence interval, 1.3, 3.9, P= 0.0002) point changes in physical functioning (on a 100-point scale), respectively, after adjusting for covariates. The relationships of changes in LBM and TBW to changes in physical functioning were linear. In women, there were no significant relationships between changes in LBM or TBW to changes in physical functioning. CONCLUSIONS: In this longitudinal analysis of relatively healthy persons with HIV infection, changes in LBM and TBW were significantly related to changes in physical functioning in men, but the magnitude of the relationship was small. In women, changes in LBM and TBW were not related to changes in physical functioning. Our data suggest that it is not necessary to measure body composition (lean and fat compartments) to understand the impact of changes in weight on physical functioning - it is sufficient to follow total body weight.

Adult↗

PubMed2001

Patterns of adherence with antiretroviral medications: an examination of between-medication differences.

OBJECTIVE: To determine whether adherence with one antiretroviral medication reliably predicts adherence with other antiretroviral medications. DESIGN: Cross-sectional repeated-measurement analysis. SETTING: Cohort study enrolling patients from Massachusetts and Rhode Island. PATIENTS: Total of 454 patients using antiretroviral medications for HIV infection. METHODS: For each antiretroviral medication, we asked patients to report how many days in the last week they had 1) missed a dose of the medication and 2) been off schedule with a dose of the medication. The reliability coefficient was used to compare between-person variance in adherence rates with total variance, which is the sum of between-person and within-person variance. RESULTS: The mean age of patients was 42 years; 28% were women and 37% were nonwhite. Sixty-six percent of patients were on three or more antiretroviral medications. Perfect adherence was reported by 42% of patients, and patients reported missing a dose on a mean of 1.5 days per week for each antiretroviral medication currently being taken. The reliability coefficient for days in the last week that the medication was missed was 0.85 (95% confidence interval [CI]: 0.83-0.87), and for days off-schedule in the last week, it was 0.88 (CI: 0.86-0.89). CONCLUSIONS: Most of the variability in antiretroviral adherence in this study was accounted for by between-patient differences in overall adherence rather than by within-patient differences in adherence patterns across medications. These data support the theory that when patients skip or are off schedule with doses, they skip or are off schedule with all the antiretroviral medications taken at that time. In the course of exploring patients' adherence issues, clinicians may find it useful to inquire about problematic dosing times. Researchers assessing adherence may not need to separately monitor adherence with each antiretroviral medication in a regimen.

Adult↗

PubMed2001

Cloning and expression of cDNAs encoding alpha1,3-fucosyltransferase homologues from Arabidopsis thaliana.

The core alpha1,3-fucosyltransferases are involved in the synthesis of glycans specific to plants and invertebrates which are known to be immunogenic and allergenic. We report the identification, isolation and characterisation of the cDNAs of three genes (FucTA, FucTB and FucTC) encoding proteins similar to alpha1,3-fucosyltransferases in Arabidopsis thaliana. Reverse transcription-polymerase chain reaction was used to amplify the full length coding sequence of FucTA. The FucTA gene, which consists of seven exons, encodes a presumptive protein of 501 amino acids showing an overall sequence identity of 66% to the protein encoded by the recently isolated mung bean Fuc-T C3 cDNA. FucTA was expressed in Pichia pastoris under the control of the AOX1 gene promoter. The soluble enzyme was found to catalyse the same reaction as mung bean core alpha1,3-fucosyltransferase as judged by analyses of the products by MALDI-TOF and high-performance liquid chromatography. The FucTB cDNA was isolated from a lambda-ZAP library, but the clone used an alternative splicing site between the second and third exon resulting in a premature stop codon. The FucTC gene encodes a protein with less than 40% identity to FucTA across 115 amino acids of a total of 401 amino acids and is a member of a new sub-family of plant alpha1,3/4-fucosyltransferase homologues.

Amino Acid Sequence↗

PubMed2001

Identification of core alpha 1,3-fucosylated glycans and cloning of the requisite fucosyltransferase cDNA from Drosophila melanogaster. Potential basis of the neural anti-horseadish peroxidase epitope.

For many years, polyclonal antibodies raised against the plant glycoprotein horseradish peroxidase have been used to specifically stain the neural and male reproductive tissue of Drosophila melanogaster. This epitope is considered to be of carbohydrate origin, but no glycan structure from Drosophila has yet been isolated that could account for this cross-reactivity. Here we report that N-glycan core alpha1,3-linked fucose is, as judged by preabsorption experiments, indispensable for recognition of Drosophila embryonic nervous system by anti-horseradish peroxidase antibody. Further, we describe the identification by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry and high performance liquid chromatography of two Drosophila N-glycans that, as already detected in other insects, carry both alpha1,3- and alpha1,6-linked fucose residues on the proximal core GlcNAc. Moreover, we have isolated three cDNAs encoding alpha1,3-fucosyltransferase homologues from Drosophila. One of the cDNAs, when transformed into Pichia pastoris, was found to direct expression of core alpha1,3-fucosyltransferase activity. This recombinant enzyme preferred as substrate a biantennary core alpha1,6-fucosylated N-glycan carrying two non-reducing N-acetylglucosamine residues (GnGnF6; Km 11 microm) over the same structure lacking a core fucose residue (GnGn; Km 46 microm). The Drosophila core alpha1,3-fucosyltransferase enzyme was also shown to be able to fucosylate N-glycan structures of human transferrin in vitro, this modification correlating with the acquisition of binding to anti-horseradish peroxidase antibody.

Amino Acid Sequence↗

PubMed2001

Patients' role in the use of radiology testing for common office practice complaints.

BACKGROUND: Radiological studies are an important component of ambulatory medical costs, and guidelines often focus on their appropriate use. However, little is known about the correlates of the use of those services, particularly the influence of patients' preferences on physicians' utilization decisions. OBJECTIVES: To study patients presenting for outpatient treatment of respiratory problems and low back pain, and to examine the magnitude of the effect of the patients' perceived need for radiological studies (radiology preference score) on use of those services. DESIGN: Cross-sectional survey. SETTING: Office practices of generalist physicians in predominantly rural areas of 8 states. PARTICIPANTS: A total of 52 generalist physicians agreed to enroll consecutive Medicare-eligible patients making office visits for respiratory problems or low back pain. Of 1785 eligible patients invited to participate, 132 (7%) refused and 1137 (69%) of 1653 returned questionnaires. MEASUREMENTS: Radiology utilization rates (plain film, computed tomographic scan, or magnetic resonance image scan) were determined by patient self-report. To assess perceived need for radiological studies, we asked patients how necessary they believed an x-ray film was in the evaluation of 4 common complaints (respiratory problems, low back pain, knee pain, and knee swelling). A summary radiology preference score was created from 3 of the 4 items, excluding the item referring to the patients' index complaint. RESULTS: Six hundred fifteen respiratory and 522 low back pain patients were enrolled; mean ages were 69 and 64 years, respectively. Radiology utilization rates were 37% for respiratory and 26% for low back pain patients. In multiple logistic regression models, for respiratory patients radiology utilization was related significantly to the radiology preference score (odds ratio [OR] for fourth quartile compared with first quartile, 1.94; 95% confidence interval [CI], 1.11-3.37; P = .02), to having a physician who owned radiology equipment (OR, 1.81; 95% CI, 1.23-2.66; P = .002), and current smoking (OR, 1.58; 95% CI, 1.04-2.41; P = .03). For low back pain patients, radiology utilization was significantly related to the radiology preference score (OR for fourth compared with first quartile, 2.55; 95% CI, 1.29-5.06; P = .007), bothersomeness of the pain (OR for fourth compared with first quartile, 3.74; 95% CI, 1.74-8.04; P<.001), and a diagnosis of osteoporosis (OR, 1.67; 95% CI, 1.01-2.75; P = .04). CONCLUSIONS: Patients' perceived need for radiological studies was significantly associated with use of those services for outpatients with respiratory problems and low back pain. These findings suggest that patients communicate their wishes to physicians, either directly or indirectly, regarding services they think are necessary. Differences in physicians' adherence to guidelines regarding radiology utilization may in part reflect variations in patients' perceived need for those services. Efforts to educate patients about when radiological studies are medically indicated may be an important complement to practice guidelines or other utilization-related financial incentives.

Aged↗

PubMed2001

Genetic model organisms in the study of N-glycans.

Recently the genomic sequences of three multicellular eukaryotes, Caenorhabditis elegans, Drosophila melanogaster and Arabidopsis thaliana, have been elucidated. A number of cDNAs encoding glycosyltransferases demonstrated to have a role in N-linked glycosylation have already been cloned from these organisms, e.g., GlcNAc transferases and alpha 1,3-fucosyltransferases. However, many more homologues of glycosyltransferases and other glycan modifying enzymes have been predicted by analysis of the genome sequences, but the predictions of full length open reading frames appear to be particularly poor in Caenorhabditis. The use of these organisms as models in glycobiology may be hampered since they all have N-linked glycosylation repertoires unlike those of mammals. Arabidopsis and Drosophila have glycosylation similar to that of other plants or insects, while our new data from MALDI-TOF analysis of PNGase A-released neutral N-glycans of Caenorhabditis indicate that there exists a range of pauci- and oligomannosidic structures, with up to four fucose residues and up to two O-methyl groups. With all these three 'genetic model organisms', however, much more work is required for a full understanding of their glycobiology.

Animals↗

PubMed2001

Identification of a cDNA encoding a plant Lewis-type alpha1,4-fucosyltransferase.

Recently, it has been found that plants, including tomato (Lycopersicon esculentum), express the Lewis-a epitope, Galbeta1,3(Fucalpha1,4)GlcNAc, on some N-glycans. By searching the EST database, it was possible to identify a tomato cDNA encoding a protein, designated FucTC, of 413 amino acids with homology to plant and mammalian alpha1,3/4-fucosyltransferases. The cDNA was expressed in Pichia pastoris and the recombinant enzyme was found to transfer fucose from GDP-Fuc (K(m) 16 microM) to lacto-N-tetraose (Galbeta1,3GlcNAcbeta1,3Galbeta1,4Glc; K(m) 80 microM) as well as to beta1,3- and beta1,4-galactosylated N-glycans. It is concluded that FucTC is responsible for the biosynthesis of Lewis-a on N-glycans in tomato.

Amino Acid Sequence↗

PubMed2001

Rapid isolation, characterization, and glycan analysis of Cup a 1, the major allergen of Arizona cypress (Cupressus arizonica) pollen.

BACKGROUND: A rapid method for the purification of the major 43-kDa allergen of Cupressus arizonica pollen, Cup a 1, was developed. METHODS: The salient feature was a wash of the pollen in acidic buffer, followed by an extraction of the proteins and their purification by chromatography. Immunoblotting, ELISA, and lectin binding were tested on both the crude extract and the purified Cup a 1. Biochemical analyses were performed to assess the Cup a 1 isoelectric point, its partial amino-acid sequence, and its glycan composition. RESULTS: Immunochemical analysis of Cup a 1 confirmed that the allergenic reactivity is maintained after the purification process. Partial amino-acid sequencing indicated a high degree of homology between Cup a 1 and allergenic proteins from the Cupressaceae and Taxodiaceae families displaying a similar molecular mass. The purified protein shows one band with an isoelectric point of 5.2. Nineteen out of 33 sera (57%) from patients allergic to cypress demonstrated significant reactivity to purified Cup a 1. MALDI-TOF mass spectrometry indicated the presence of three N-linked oligosaccharide structures: GnGnXF(3) (i.e., a horseradish peroxidase-type oligosaccharide substituted with two nonreducing N-acetylglucosamine residues), GGnXF(3)/GnGXF(3) (i.e., GnGnXF with one nonreducing galactose residue), and (GF)GnXF(3)/Gn(GF)XF(3) (with a Lewisa epitope on one arm) in the molar ratio 67:8:23. CONCLUSION: The rapid purification process of Cup a 1 allowed some fine studies on its properties and structure, as well as the evaluation of its IgE reactivity in native conditions. The similarities of amino-acid sequences and some complex glycan stuctures could explain the high degree of cross-reactivity among the Cupressaceae and Taxodiaceae families.

Allergens↗

PubMed2001

Antibody binding to venom carbohydrates is a frequent cause for double positivity to honeybee and yellow jacket venom in patients with stinging-insect allergy.

BACKGROUND: Up to 50% of patients with stinging-insect allergy have double-positive RAST results to honeybee and yellow jacket (YJ) venom. True double sensitization and crossreactivity through venom hyaluronidases are considered main reasons for this multiple reactivity. OBJECTIVE: We investigated the role of antibodies against cross-reactive carbohydrate determinants in venom double positivity. METHODS: CAP inhibition experiments were performed with crude oilseed rape (OSR) and timothy grass pollen extracts and a neoglycoprotein construct displaying a MUXF glycan, as present in pineapple-stem bromelain (MUXF-BSA). CAP to OSR was used as a rough measure for carbohydrate-specific IgE in individual sera. RESULTS: CAP results to OSR pollen were positive in 2 of 14 single-positive honeybee venom sera, 2 of 16 single-positive YJ venom sera, and 33 (80.5%) of 41 double-positive sera (P < .00001, chi(2) test). CAP inhibition was performed in 16 selected patients with a CAP class of 3 or higher to both venoms. In 9 of 11 patients with a highly positive CAP result to OSR (CAP score to OSR > CAP score to second venom), pollen extracts, MUXF-BSA, or both were able to completely inhibit IgE binding to one of the venoms, whereas this was not the case in 5 patients with a negative or weakly positive CAP result to OSR (CAP score to OSR < CAP score to second venom). CONCLUSIONS: The data suggest that carbohydrate-specific IgE is a major cause for the double positivity to honeybee and YJ venom seen in patients with Hymenoptera allergy. Because these antibodies may have low clinical relevance, they may severely impede the correct diagnosis of Hymenoptera venom allergy.

Animals↗

PubMed2001

Analysis of Asn-linked glycans from vegetable foodstuffs: widespread occurrence of Lewis a, core alpha1,3-linked fucose and xylose substitutions.

The N-glycans from 27 "plant" foodstuffs, including one from a gymnospermic plant and one from a fungus, were prepared by a new procedure and examined by means of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). For several samples, glycan structures were additionally investigated by size-fractionation and reverse-phase high-performance liquid chromatography in conjunction with exoglycosidase digests and finally also (1)H-nuclear magnetic resonance spectroscopy. The glycans found ranged from the typical vacuolar "horseradish peroxidase" type and oligomannose to complex Le(a)-carrying structures. Though the common mushroom exclusively contained N-glycans of the oligomannosidic type, all plant foods contained mixtures of the above-mentioned types. Apple, asparagus, avocado, banana, carrot, celery, hazelnut, kiwi, onion, orange, pear, pignoli, strawberry, and walnut were particularly rich in Le(a)-carrying N-glycans. Although traces of Le(a)-containing structures were also present in almond, pistachio, potato, and tomato, no such glycans could be found in cauliflower. Coconut exhibited almost exclusively N-glycans containing only xylose but no fucose. Oligomannosidic N-glycans dominated in buckwheat and especially in the legume seeds mung bean, pea, peanut, and soybean. Papaya presented a unique set of hybrid type structures partially containing the Le(a) determinant. These results are not only compatible with the hypothesis that the carbohydrate structures are another potential source of immunological cross-reaction between different plant allergens, but they also demonstrate that the Le(a)-type structure is very widespread among plants.

Asparagine↗

PubMed2001

Effects of different monetary incentives on the return rate of a national mail survey of physicians.

BACKGROUND: Mail surveys of physicians have been characterized by lower response rates than general population surveys, raising concerns about nonresponse bias. Although monetary incentives have routinely been used to improve survey response among physicians, questions remain regarding how much of an incentive is most cost-effective. The present study seeks to further examine the effects of incentive size on response rates to a national mail survey of physicians. METHODS: This study used a random sample of 873 physicians practicing in the United States; the response rate was 65% (n = 563). Respondents were randomly assigned to receive a $5, $10, or $20 cash incentive in the initial mailing. Except for the magnitude of the incentive, the procedures for each condition were identical, with each respondent receiving up to 3 follow-up mailings and 2 telephone calls. RESULTS: Overall response rates ranged from 60.3% for the $5 incentive category to 68.0% for the $10 incentive category. Differences in overall response rates across the incentive categories, however, were not significant. Higher levels of incentives also did not significantly reduce the number of mail and/or telephone interventions required to reach the target response rate of 60.0%. As expected, aggregate costs (excluding labor) were lowest for the $5 incentive group. CONCLUSIONS: Our findings suggest that changes in the magnitude of incentive do not automatically result in increases in survey response among physicians. Possible reasons for this lack of effect as well as alternatives to monetary incentives are addressed.

Bias↗

PubMed2001

Adjusting for patient characteristics when analyzing reports from patients about hospital care.

OBJECTIVES: To determine which patient characteristics are associated with reports and ratings of hospital care, and to evaluate how adjusting reports and ratings for hospital differences in such variables affects comparisons among hospitals. DESIGN: A telephone survey of a sample of patients hospitalized in 22 hospitals in a single city and a statewide mail survey of hospitalized patients. MEASURES: The surveys assessed: respect for patients' preferences, coordination of care, information exchange between patient and providers, physical care, emotional support, involvement of family and friends, and transition and continuity. The surveys also asked patients to rate their doctors, nurses, and other hospital staff. RESULTS: The variables with the strongest and most consistent associations with patient-reported problems were age and reported health status. Patient gender and education level also sometimes predicted reports and/or ratings. Models including these variables explained only between 3% and 8% of the variation in reports and ratings. CONCLUSIONS: The impact of adjusting for patient characteristics on hospital rankings was small, although a larger impact would be expected when comparing hospitals with more variability in types of patients. Nevertheless, we recommend adjusting at least for the most important predictors, such as age and health status. Such adjustment helps alleviate concerns about bias. It also may be useful to present data for certain groups of patients (ie, medical, surgical, obstetric) separately to facilitate interpretation and quality improvement efforts.

Age Factors↗

PubMed2001

Effect of resistance training on self-reported physical functioning in HIV infection.

PURPOSE: To assess whether progressive resistance training (PRT) improves functional status, measured using a validated Physical Function Scale, in both wasted and nonwasted patients with HIV infection, and to compare the relative contributions of increased lean body mass (LBM) and increased strength with the change in physical function. METHODS: Six patients with AIDS wasting and 19 patients with HIV but without wasting trained three times per week for 8 wk, followed by 8 wk of usual activity. Physical function, strength, and LBM were measured at 0, 8, and 16 wk. Self-reported physical functioning was measured using the physical functioning subscale of the Medical Outcomes Study (MOS) Short Form-36 (SF-36) questionnaire. RESULTS: Significant improvements occurred in strength (1-RM averaged for four machines increased 44% in the nonwasted and 60% in the wasted patients, each P < 0.0001) and LBM (2.3% increase in the nonwasted and 5.3% in the wasted patients, each P < 0.05) with resistance training. Physical function increased significantly in the wasted subjects (6 points, P < 0.02) but not in the nonwasted subjects, so that at 16 wk the wasted subjects functioned at a higher level than the nonwasted patients (P < 0.05). Both increase in LBM (P < 0.001) and increase in strength (P < 0.001) were significantly and independently associated with increase in physical function. CONCLUSION: PRT increases functional status in patients with HIV wasting, both by increasing strength and by increasing LBM.

Activities of Daily Living↗

PubMed2000

Physician-patient communication in HIV disease: the importance of patient, physician, and visit characteristics.

BACKGROUND: Although previous work that considered a variety of chronic conditions has shown that higher quality physician-patient communication care is related to better health outcomes, the quality of physician-patient communication itself for patients with HIV disease has not been well studied. OBJECTIVE: To determine the relationship of patient, visit, physician, and physician practice characteristics to two measures of physician-patient communication for patients with HIV disease. DESIGN: Cross-sectional survey of physicians and patients. SETTING: Cohort study enrolling patients from throughout eastern Massachusetts. STUDY SUBJECTS: 264 patients with HIV disease and their their primary HIV physicians (n = 69). MEASUREMENTS: Two measures of physician-patient communication were used, a five-item general communication measure (Cronbach's alpha = 0.93), and a four-item HIV-specific communication measure that included items about alcohol, drug use, and sexual behaviors (Cronbach's alpha = 0.92). RESULTS: The mean age of patients was 39. 5 years, 24% patients were women, 31.1% were nonwhite, and 52% indicated same-sex contact as their principal HIV risk factor. The mean age of physicians was 39.1 years, 33.3% were female, 39.7% were specialists, and 25.0% self-identified as gay, lesbian, or bisexual. In multivariable models relating patient and visit characteristics to general communication, longer reported visit length (p<.0001), longer duration of the physician-patient relationship (p =.02), and female gender (p =.04) were significantly associated with better communication. The interaction of patient gender and visit length was also significant (p =.02); longer visit length was more strongly associated with better general communication for male than female patients. In similar models relating patient and visit characteristics to HIV-specific communication, longer visit length (p <.0001) and less advanced disease stage (p =.009) were associated with better communication. In multivariable models relating physician and practice characteristics to general communication no variables were significant. However, both female physician gender (p =.002) and gay/lesbian/bisexual sexual preference (p =.003) were significantly associated with better HIV-specific communication. CONCLUSIONS: In this study, female and homosexual physicians provided higher quality HIV-specific communication than male and heterosexual physicians. Better understanding the processes by which female and homosexual physicians achieve higher quality communication may help other physicians communicate more effectively. Health care providers and third-party payers should be aware that shorter visits may compromise physician-patient communication, and that this effect may be more consequential for male patients.

Adult↗

PubMed2000

Health-related quality of life in patients with human immunodeficiency virus infection in the United States: results from the HIV Cost and Services Utilization Study.

PURPOSE: To measure health-related quality of life among adult patients with human immunodeficiency virus (HIV) disease; to compare the health-related quality of life of adults with HIV with that of the general population and with patients with other chronic conditions; and to determine the associations of demographic variables and disease severity with health-related quality of life. SUBJECTS AND METHODS: We studied 2,864 HIV-infected adults participating in the HIV Cost and Services Utilization Study, a probability sample of adults with HIV receiving health care in the contiguous United States (excluding military hospitals, prisons, or emergency rooms). A battery of 28 items covering eight domains of health (physical functioning, emotional well-being, role functioning, pain, general health perceptions, social functioning, energy, disability days) was administered. The eight domains were combined into physical and mental health summary scores. SF-36 physical functioning and emotional well-being scales were compared with the US general population and patients with other chronic diseases on a 0 to 100 scale. RESULTS: Physical functioning was about the same for adults with asymptomatic HIV disease as for the US population [mean (+/- SD) of 92+/-16 versus 90+/-17) but was much worse for those with symptomatic HIV disease (76+/-28) or who met criteria for the acquired immunodeficiency syndrome (AIDS; 58+/-31). Patients with AIDS had worse physical functioning than those with other chronic diseases (epilepsy, gastroesophageal reflux disease, clinically localized prostate cancer, clinical depression, diabetes) for which comparable data were available. Emotional well-being was comparable among patients with various stages of HIV disease (asymptomatic, 62+/-9; symptomatic, 59+/-11; AIDS, 59+/-11), but was significantly worse than the general population and patients with other chronic diseases except depression. In multivariate analyses, HIV-related symptoms were strongly associated with physical and mental health, whereas race, sex, health insurance status, disease stage, and CD4 count were at most weakly associated with physical and mental health. CONCLUSIONS: There is substantial morbidity associated with HIV disease in adults. The variability in health-related quality of life according to disease progression is relevant for health policy and allocation of resources, and merits the attention of clinicians who treat patients with HIV disease.

Adult↗

PubMed2000

Relation of lean body mass to health-related quality of life in persons with HIV.

OBJECTIVE: To determine the nature and strength of the relation between lean body mass and measures of health-related quality-of-living (HRQL) including physical functioning in men and women with HIV. DESIGN: Cross-sectional analysis using 619 patients with HIV infection from two cities in the northeastern United States. MAIN OUTCOME MEASURES: Lean body mass (LBM) was assessed by bioimpedance analysis (BIA). Physical functioning, general health perceptions, energy/fatigue, and number of days spent in bed in the last month were determined by patient self-report. RESULTS: Data from 450 men and 169 women were analyzed. Mean age was 39 years, 37.6% were nonwhite, and mean CD4 counts were 352 cells/ml. In multivariable models, higher LBM was significantly associated with better physical functioning in men but not in women. In men, a 10-kg increment in LBM was associated with a 3.7 point (95% confidence interval [CI], 0.19-7.2) increment in physical functioning (0-100 scale). In similar analyses, higher LBM was significantly associated with better general health perceptions (10-kg increment in LBM associated with a 4.8 point [95% CI, 1.4-8.1] increment in general health perceptions), and fewer days in bed in the last month (10-kg increment in LBM associated with 0.9 [95% CI, -1.8-0] fewer days in bed). Lean body mass was not independently associated with energy/fatigue. CONCLUSIONS: In this diverse population of persons with HIV, LBM was significantly related to physical functioning and other measures of HQRL in men, but not in women. In men, the relation was linear but relatively weak. These data have potential implications for assessing the clinical impact of interventions aimed at increasing LBM. Even in men, increases in LBM in the ranges that are currently achievable may produce relatively small improvements in physical functioning and other measures of HRQL.

Adipose Tissue↗

PubMed2000

Molecular cloning and functional expression of beta1, 2-xylosyltransferase cDNA from Arabidopsis thaliana.

The transfer of xylose from UDP-xylose to the core beta-linked mannose of N-linked oligosaccharides by beta1,2-xylosyltransferase (XylT) is a widespread feature of plant glycoproteins which renders them immunogenic and allergenic in man. Here, we report the isolation of the Arabidopsis thaliana XylT gene, which contains two introns and encodes a 60.2 kDa protein with a predicted type II transmembrane protein topology typical for Golgi glycosyltransferases. Upon expression of A. thaliana XylT cDNA in the baculovirus/insect cell system, a recombinant protein was produced that exhibited XylT activity in vitro. Furthermore, the recombinant enzyme displayed XylT activity in vivo in the insect cells, as judged by the acquired cross-reaction of cellular glycoproteins with antibodies against the beta1,2-xylose epitope. The cloned XylT cDNA as well as the recombinant enzyme are essential tools to study the role of beta1,2-xylose in the immunogenicity and allergenicity of plant glycoproteins at the molecular level.

Amino Acid Sequence↗

PubMed2000

Physician manipulation of reimbursement rules for patients: between a rock and a hard place.

CONTEXT: Health plan utilization review rules are intended to enforce insurance contracts and can alter and constrain the services that physicians provide to their patients. Physicians can manipulate these rules, but how often they do so is unknown. OBJECTIVE: To determine the frequency with which physicians manipulate reimbursement rules to obtain coverage for services they perceive as necessary, and the physician attitudes and personal and practice characteristics associated with these manipulations. DESIGN, SETTING, AND PARTICIPANTS: A random national sample of 1124 practicing physicians was surveyed by mail in 1998; the response rate was 64% (n = 720). MAIN OUTCOME MEASURE: Use of 3 different tactics "sometimes" or more often in the last year: (1) exaggerating the severity of patients' conditions; (2) changing patients' billing diagnoses; and/or (3) reporting signs or symptoms that patients did not have to help the patients secure coverage for needed care. RESULTS: Thirty-nine percent of physicians reported using at least 1 tactic "sometimes" or more often in the last year. In multivariate models comparing these physicians with physicians who "never" or "rarely" used any of these tactics, physicians using these tactics were more likely to (1) believe that "gaming the system" is necessary to provide high-quality care today (odds ratio [OR], 3.67; 95% confidence interval [CI], 2.54-5.29); (2) have received requests from patients to deceive insurers (OR, 2.44; 95% CI, 1.72-3.45); (3) feel pressed for time during patient visits (OR, 1.69; 95% CI, 1.21-2.37); and (4) have more than 25% of their patients covered by Medicaid (OR, 1.60; 95% CI, 1.08-2.38). Notably, greater worry about prosecution for fraud did not affect physicians' use of these tactics (P = .34). Of those reporting using these tactics, 54% reported doing so more often now than 5 years ago. CONCLUSIONS: A sizable minority of physicians report manipulating reimbursement rules so patients can receive care that physicians perceive is necessary. Unless novel strategies are developed to address this, greater utilization restrictions in the health care system are likely to increase physicians' use of such manipulative "covert advocacy" tactics.

Attitude of Health Personnel↗