Intracellular signaling consequences of anti-IL-2Ralpha blockade by daclizumab.
Explore the source record for details and available documents.
Antibodies, Monoclonal↗
Biomedical subjects
C Yu
Publications and source records attributed to C Yu.
Mixed hematopoietic chimerism after hematopoietic stem cell allografts.
Explore the source record for details and available documents.
Animals↗
Evaluation of two self-care treatments for prevention of vaginal candidiasis in women with HIV.
Vaginal candidiasis (VC) is a common concern for women living with HIV infection. The authors evaluated the effectiveness of two self-care approaches to prophylaxis of VC among HIV-infected women, weekly intravaginal application of Lactobacillus acidophilus or weekly intravaginal application of clotrimazole tablets, in a randomized, double-blind, placebo-controlled trial. VC was defined as a vaginal swab positive for Candida species in the presence of signs/symptoms of vaginitis and the absence of a diagnosis of Trichomonas vaginalis or bacterial vaginosis. Thirty-four episodes of VC occurred among 164 women followed for a median of 21 months. The relative risk of experiencing an episode of VC was 0.4 (95% CI = 0.2, 0.9) in the clotrimazole arm and 0.5 (95% CI = 0.2, 1.1) in the Lactobacillus acidophilus arm. The estimated median time to first episode VC was longer for clotrimazole (p = .03, log rank test) and Lactobacillus acidophilus (p = .09, log rank test) compared with placebo. Vaginal yeast infections can be prevented with local therapy. Education about self-care for prophylaxis of VC should be offered to HIV-infected women.
Administration, Intravaginal↗
Factors associated with vaginal yeast infections in HIV-positive women.
To better understand factors associated with symptomatic and asymptomatic vulvovaginal candidiasis, including the role of immune compromise and patient self-report, a cross-sectional analysis of factors associated with the isolation of yeast from vaginal swabs and clinical diagnosis of Candida vaginitis (CV) among 184 HIV-infected women was conducted. Sixty-four (35%) of the women had vaginal swabs positive for yeast. Nineteen (10%) women met the case definition for CV. In a logistic regression model, only CD4 < or = 100 cells/mm3 was predictive of CV (adds ratio = 4.5; 95% confidence interval = 1.0, 20; p = .05). The predictive value of patient self-report of CV was only 12%. This study demonstrates that all HIV-infected women should receive a regular and thorough gynecologic evaluation, regardless of self-reported symptoms. HIV-infected women will benefit from education about prevention and treatment of CV, and women whose CD4 counts are low may wish to consider prophylaxis for CV.
AIDS-Related Opportunistic Infections↗
Dosimetry of source stepping for intravascular brachytherapy.
PURPOSE: Both beta and gamma sources of fixed length are currently used in the catheter-based intravascular brachytherapy (IVBT). Source stepping is often used to treat a lesion longer than the effective treatment length of the source. A major challenge for the stepping procedure is to attain a perfect dosimetric match (uniform dose) at the source junction. This work presents a quantitative and systematic dosimetric analysis for source stepping during an IVBT procedure. MATERIALS AND METHODS: The three most commonly used beta and gamma sources (192Ir by BEST, 90Sr by NOVOSTE and 32P by Guidant) were studied using the EGSnrc Monte Carlo code. Dose distributions were calculated for a perfect end-to-end match and for a range of end-to-end gaps and overlaps between consecutive steps. RESULTS: It is found that a perfect end-to-end match during source stepping yields uniform dose distribution in the region of source junction. The doses in the case of a mismatch (in the presence of an end-to-end gap or overlap) were found to be significantly different from those with the perfect end-to-end match. The dose deviation depends on the size of the gap or overlap, radial distance and type of source. The dose deviation decreases with radial distance for a given gap/overlap. For example, for a gap/overlap of 2 mm, dose decreases/increases of 30%, 55% and 60% were found at the radial distance of 2 mm from source for 192Ir, 90Sr and 32P, respectively. These dose deviations are reduced by approximately 10% when the radial distance increases from 2 to 3 mm. The dose deviations for gaps or overlaps in the range of 0-5 mm are presented. CONCLUSIONS: During an IVBT procedure involving source stepping, a perfect end-to-end match is always desired. Significant underdosing or overdosing can occur in the case of a source mismatch. A considerable caution should be exercised to ensure that sources are properly matched.
Beta Particles↗
Spatial-frequency and orientation tuning in psychophysical end-stopping.
A psychophysical analog to cortical receptive-field end-stopping has been demonstrated previously in spatial filters tuned to a wide range of spatial frequencies (Yu & Levi, 1997a). The current study investigated tuning characteristics in psychophysical spatial filter end-stopping. When a D6 (the sixth derivative of a Gaussian) target is masked by a center mask (placed in the putative spatial filter center), two end-zone masks (placed in the filter end-zones) reduce thresholds. This "end-stopping" effect (the reduction of masking induced by end-zone masks) was measured at various spatial frequencies and orientations of end-zone masks. End-stopping reached its maximal strength when the spatial frequency and/or orientation of the end-zone masks matched the spatial frequency and/or orientation of the target and center mask, showing spatial-frequency tuning and orientation tuning. The bandwidths of spatial-frequency and orientation tuning functions decreased with increasing target spatial frequency. At larger orientation differences, however, end-zone masks induced a secondary facilitation effect, which was maximal when the spatial frequency of end-zone masks equated the target spatial frequency. This facilitation effect might be related to certain types of contour and texture perception, such as perceptual pop-out.
Adult↗
Issues in the design of a multirate model-based controller for a nonlinear drug infusion system.
Multivariable controller design for the regulation of mean arterial pressure (MAP) and cardiac output (CO) in congestive heart failure patients is restricted by the limited frequency of CO sampling. Performance criteria for the controller specify maximum allowable transient settling times for both variables, and the design should account for the inherent multirate nature of the process in order to satisfy these criteria. We present a multirate model predictive control (MPC) design for MAP and CO regulation by combined infusion of sodium nitroprusside and dopamine, based on a comprehensive nonlinear model of the system. The multirate MPC algorithm is based on nonlinear quadratic dynamic matrix control. To reduce computation time, we introduce a selective linearization technique that linearizes the model on the basis of trends in the plant-model mismatch. The problem is complicated by restrictions on initial dopamine infusion, prescribed to avoid extremely slow responses. We present a novel rule-based override (RBO) to the MPC controller that uses a set of heuristics to initialize dopamine. The performance of the MPC/RBO controller is illustrated using simulation results.
Algorithms↗
RUBIDIUM, a program for computer-aided assignment of two-dimensional NMR spectra of polypeptides.
Taking advantage of the rule-based expert system technology, a program named RUBIDIUM (Rule-Based Identification In 2D NMR Spectrum) was developed to accomplish the automatic 1H NMR resonance assignments of polypeptides. Besides noise elimination and peak selection capabilities, RUBIDIUM detects the cross-peak patterns of amino acid residues in the COSY spectrum, assigning these patterns to amino acid types, performing sequential assignments using combined COSY/NOESY spectra, and finally, achieving the total assignment of the 1H NMR spectrum.
Amino Acid Sequence↗
A novel percutaneous barrier device that permits safe subcutaneous access.
Successful subcutaneous access is important for optimal management of internal artificial organs and treatment of many diseases. However, skin downgrowth and tissue infection are still significant problems in the use of devices that require long-term subcutaneous access. The authors developed a new percutaneous device that provides a unique biologic boundary with surrounding connective tissue while minimizing the risk of complications. This new percutaneous device is made of a circumferential, strong, thin, and flexible mesh collar with millimeter size holes for connecting the structure. It has two distinct functional portions: a connecting zone and a sealing line. The most important features of the structure are: 1) Connective tissue grows through the millimeter size pores of the connecting zone to form a strong bond between the device and healthy tissue. 2) The millimeter size pores of the connecting zone allow capillaries to grow through its entire surface, ensuring sufficient blood supply. 3) The tissue of the connecting zone and the device surface form a biosealed junction (sealing line). This sealing line is protected by the connecting zone and is free from external forces acting on local skin. 4) The device is generally functional immediately after surgical implantation. The subcutaneous perimeter of the functional dome contains extruded rigid rings of millimeter size holes permitting growth of subcutaneous tissue through the device. This functions as the minor connecting structure of the device. Four of five implanted rabbits have remained healthy 8 months postimplantation without antibiotic administration. The fifth rabbit died 4 months postimplantation for reasons unrelated to the device. Gross or histopathologic inspection revealed no signs of tissue injury or inflammation. Growth of healthy connective tissue was clearly observed. These results indicate this percutaneous device can provide a strong, stable, and effective connection to internal organs without bioboundary damage, skin downgrowth, or tissue infection.
Animals↗
The LPD-II: a modified locked percutaneous device that permits safe subcutaneous access.
A locked percutaneous device, the LPD-I (previously described as LPD), is effective in overcoming the problems of skin downgrowth and local tissue infection; however, it can only be implanted at a site providing adequate subcutaneous adipose tissue to attach to the subcutaneous connector of the LPD-I. A modified device, the LPD-II, has been developed that has a thin dome and skin connector but does not have a subcutaneous tissue connector. In addition, a newly designed structure called the skin stop collar (SSC) has been developed. It is positioned just beneath the mesh collar described in the LPD-I to further improve the function of the LPD-II. Six rabbits were implanted with one LPD-II without the SSC (group 1) and five rabbits were implanted with one LPD-II with the SSC (group 2). For more than 6 months, two of the implants in group 1 rabbits were successful. Four of the implants in group 2 rabbits were successful for more than 1 year. One of the animals in group 2 died of causes unrelated to the device. We conclude the following: the mesh collar skin connector can function well as a locked percutaneous device without the subcutaneous tissue connector; the LPD-II can be implanted in any site and does not require the presence of subcutaneous adipose tissue; and the SSC may increase the success rate of LPD-II implantation provided the mesh collar is made of soft material.
Adipose Tissue↗
Acute and subacute toxicity study of water-soluble polyalkylsulfonated C60 in rats.
Polyalkylsulfonated C60, or FC4S, a highly water-soluble caged fullerene derivative, is believed to be a free radical remover or an antioxidant in biological systems. A 50 mg/ml aqueous solution was prepared as a master solution and administered to female Sprague-Dawley CD(Crl:CD(SD)BR) rats in a single-dose acute toxicity study or a 12-day subacute toxicity study where rats were given the solution daily. In a study of the median lethal dose (LD50), no rats died after oral administration, and thus FC4S was considered to be nontoxic if administered orally. In an LD50 intraperitoneal injection study, rats died within 30 hr after injection; the LD50 was determined to be approximately 600 mg per kilogram of body weight. Rats injected with the compound intraperitoneally or intravenously immediately eliminated the compound through the kidney; the kidney appeared to be the primary target organ. The compound induced a distinct lysosome-overload nephrosis, a phagolysosomal nephropathy characterized by a tinctorial difference between the outer cortex and the inner cortex and the medulla. The affected outer cortex showed a diffuse degeneration, with the presence of numerous large vacuoles and cytoplasmic aggregates in the tubular epithelium. The phagolysosomal nephropathy was detected in rats after acute exposure as well as in the surviving rats following 1 intraperitoneal injection of 500 mg/kg or intravenous injection of 100 mg/kg. Ultrastructural investigation revealed numerous membranous conglomerates characteristic of phagolysosomal and/or lysosomal inclusions in the cytoplasm of the renal tubular epithelium. These conglomerates were confined to the vacuole, electron-dense, and unevenly stained. They varied in size and shape and were fused or aggregated. Occasional phagolysosomes were also observed in the endothelial cells of the peritubular plexus. A preliminary study of microsomal enzyme activity analysis revealed a suppression effect of liver cytochrome P-450-dependent monooxygenase activities, including cytochrome P-450, cytochrome b5, and benzo(a)pyrene hydroxylase, but an increased level of kidney cytochrome P-450-dependent monooxygenase activities, including NADPH-cytochrome P-450 reductase. The significance of these enzyme alterations was not well determined. Further study is needed to clarify the correlation between the alterations of microsomal enzyme activity and the nephropathy of lysosomal overload-induced changes. These changes may serve as a biological marker in toxicity screening tests for this class of compound.
Administration, Oral↗
Fatal Epstein-Barr virus myocarditis in a child with repetitive myocarditis.
Fatal Epstein-Barr virus (EBV) myocarditis occurred in a 9-year-old female with a history of two prior discrete episodes of myocarditis, the first associated with chicken pox and the second of undetermined origin. Serologic studies during the fatal episode were characteristic of acute EBV infection, and EBV genome was detected by polymerase chain reaction (PCR) amplification of DNA extracted from autopsy heart and liver. PCRs for enteroviruses and cardiac viral culture were negative. An intense mononuclear cell infiltrate in the myocardium consisted entirely of T cells, without identifiable B cells. Human leukocyte antigen HLA-DR analysis using frozen tissue obtained postmortem revealed antigens DR4 and DR13. DR4 is associated with some autoimmune disorders, as well as idiopathic dilated cardiomyopathy. We postulate that an aberrant immune response, possibly associated with the DR4 locus, was responsible for the repetitive episodes of myocarditis in this patient.
Acute Disease↗
The Association for Volunteer Administration and professionalization of the field: suggestions from a survey for the membership.
This article analyzes results from a comprehensive survey of members of the Association for Volunteer Administration (AVA), conducted in 1992-93. Two-thirds of the membership completed the mail questionnaire. The article elaborates findings from the survey in the areas of: professional background of members, their position in volunteer administration, their volunteer programs, interest in research in the field, and attitudes toward their work, organization, and profession. The concluding section discusses implications of the findings with respect to the AVA and professionalization of the field.
Administrative Personnel↗
Radioactive materials in biosolids: national survey, dose modeling, and publicly owned treatment works (POTW) guidance.
The Nuclear Regulatory Commission (NRC) announced the availability of three new documents concerning radioactive materials in sewage sludge and ash from publicly owned treatment works (POTW). One of the documents is a report presenting the results of a volunteer survey of sewage sludge and ash samples provided by 313 POTWs. The second document is a dose modeling document, using multiple exposure pathway modeling focused on a series of generic scenarios, to track possible exposure of POTW workers and members of the general public to radioactivity from the sewage sludge or ash. The third document is a guidance report providing recommendations on the management of radioactivity in sewage sludge and ash for POTW owners and operators. This paper explains how radioactive materials enter POTWs, provides criteria for evaluating levels of radioactive material in sludge and ash, and gives a summary of the results of the survey and dose modeling efforts.
Data Collection↗
Association of interleukin-10 gene -592 A/C polymorphism with the clinical and pathological diversity of lupus nephritis.
OBJECTIVE: To investigate the interleukin-10 (IL-10) gene -592 A/C polymorphism in Chinese patients with lupus nephritis (LN) and evaluate the role of lL-10 in the pathogenesis and clinical/pathological diversity of LN. METHODS: Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analyses were used to detect the IL-10 gene -592 A/C polymorphism in 265 LN patients and 100 ethnically matched controls. Frequencies of the genotypes were compared between LN patients and controls and among LN patients with different pathological classes. The clinical and pathological characteristics of the patients with different genotypes were also analyzed. Serum IL-10 levels of the patients were determined by ELISA. RESULTS: No significant differences were found in the distribution of the polymorphism between healthy controls and LN patients. The parameters of disease activity index (DAI), percentage of positive serum anti-dsDNA antibodies, proteinuria and hematuria, and frequency of glomerular thrombi were all higher in patients with -592 AC/CC genotypes than those with AA genotype. AC/CC genotypes were more frequent in patients with LN-IV than in those with LN-II and Va. There was no significant difference in the serum IL-10 levels in patients with these three genotypes. CONCLUSION: The IL-10 gene -592 A/C polymorphism appears to be associated with disease activity and renal pathology of LN, but not associated with LN susceptibility or serum IL-10 levels. Patients carrying the -592 C allele had a higher risk of diffuse proliferative glomerulonephritis, indicating the genetic influence of the IL-10 gene polymorphism in the renal lesions of LN.
Adolescent↗
Fetal heart rate monitoring casebook. Persistent bradycardia.
Explore the source record for details and available documents.
Accidental Falls↗