Digital signal processing actigraphy.
Explore the source record for details and available documents.
Humans↗
Biomedical subjects
A Vo
Publications and source records attributed to A Vo.
Successful use of oral ganciclovir for the treatment of intrauterine cytomegalovirus infection in a renal allograft recipient.
Congenital cytomegalovirus (CMV) infection occurs in approximately 1% of newborns and is the leading infectious cause of congenital birth defects. Female renal allograft recipients who develop CMV infection during pregnancy are at risk for both graft dysfunction and fetal morbidity. DNA-based analysis of amniotic fluid (AF) from at-risk pregnancies has been suggested as an adjunct/substitute for traditional culture. We have shown that CMV-polymerase chain reaction of AF is a useful diagnostic test for congenital CMV infection. Using this test we diagnosed CMV infection in the fetus of a 30-year-old renal transplant recipient. As termination was not an option for the family, the patient was extensively counseled and treated with oral ganciclovir. This resulted in clearance of the virus from the AF and the delivery of a healthy newborn girl, free of CMV disease. This is the first reported case to our knowledge of successful use of maternal ganciclovir to treat intrauterine CMV infection in a pregnant renal transplant recipient.
Adult↗
Reactive oxygen species promote tyrosine phosphorylation and capacitation in equine spermatozoa.
The objective of this study was to examine the influence of reactive oxygen species (ROS) on equine sperm capacitation. Motile equine spermatozoa were separated on a discontinuous Percoll gradient, resuspended at 10 x 10(6)ml in Tyrode's medium supplemented with BSA (0.5%) and polyvinyl alcohol (0.5%) and incubated at 39 degrees C for 2h with or without the xanthine (X; 0.1mM)-xanthine oxidase (XO; 0.01 U/ml) system or NADPH (0.25 mM). The importance of hydrogen peroxide or superoxide for capacitation was determined by the addition of catalase (CAT; 150 U/ml) or superoxide dismutase (SOD; 150 U/ml), respectively. Following incubation, acrosomal exocytosis was induced by a 5 min incubation at 39 degrees C with progesterone (3.18 microM), and sperm viability and acrosomal integrity were then determined by staining with Hoechst 33258 and fluoroisothiocyanate-conjugated Pisum sativum agglutin. To examine tyrosine phosphorylation, treatments were subjected to sodium dodecyl sulfate-polyacrylaminde gel electrophoresis (SDS-PAGE) followed by Western blot analysis with the anti-phosphotyrosine antibody (alpha-PY; clone 4G10). Capacitation with the X-XO system or NADPH led to a significant (P<0.0001) increase in live acrosome-reacted spermatozoa compared to controls. The addition of CAT or SOD prevented the increase in live acrosome-reacted spermatozoa associated with X-XO treatment. Incubation with the X-XO system was also associated with a significant (P<0.005) increase in tyrosine phosphorylation when compared to controls, which could be prevented by the addition of CAT but not SOD. This study indicates that ROS can promote equine sperm capacitation and tyrosine phosphorylation, suggesting a physiological role for ROS generation by equine spermatozoa.
Animals↗
Intravenous immune globulin treatment inhibits crossmatch positivity and allows for successful transplantation of incompatible organs in living-donor and cadaver recipients.
BACKGROUND: Sensitization to human leukocyte antigens (HLA) is a significant barrier to transplantation. Currently, no proven therapy exists to improve access to transplantation for highly sensitized patients. Here, we report a novel approach using intravenous immune globulin to modulate anti-HLA antibody and improve the chances for successful transplantation. PATIENTS AND METHODS: Forty-five highly HLA-sensitized patients presented as candidates for living-donor kidney transplantation (n=28), cadaveric kidney transplantation (n=15), or heart transplantation (n=2). All patients had a positive CDC crossmatch (CMX) with their donors. In living-donor recipients, intravenous immune globulin (IVIG) was added to the CMX evaluation to determine whether blocking antibodies present in IVIG could inhibit cytotoxicity. For those who showed in vitro inhibition with IVIG (n=26), IVIG was administered (usually as a single dose, 2 g/kg) and the CDC CMX was repeated against the prospective donor immediately after IVIG infusion. If negative, the patient underwent transplantation with their living-donor kidney within 24 to 72 hr. A similar but modified protocol was performed for cadaver donor candidates, all of whom were highly sensitized and had had CMX positivity with multiple donors, negating transplantation. Reductions in CMX positivity, posttransplantation serum creatinine level, number and severity of rejection episodes, and patient and graft survival rates were determined. RESULTS: Forty-two patients underwent transplantation. IVIG treatment completely abrogated the donor-specific CMXs in 35 of 42 patients. In the remaining 7 patients, the CDC CMX was inhibited, but flow cytometry CMXs remained positive. A total of 13 (31%) of 42 recipients developed rejection episodes 3 to 49 days after transplantation. Three grafts (7%) were lost to rejection. Mean serum creatinine level at 24 months was 1.4+/-0.4 mg/dL. Patient and graft survival rates were 97.6% and 89.1%, respectively, at 24 months. CONCLUSIONS: The in vitro IVIG CMX technique predicts the ability of IVIG to reduce anti-HLA antibody levels in highly sensitized patients. Subsequent in vivo IVIG treatment of responders eliminates the positive CDC CMX and allows for successful transplantation. Thus a positive CMX result is not necessarily a contraindication for transplantation and allows access to transplantation for patients for whom it was previously contraindicated.
Adolescent↗
Early and pre-symptomatic neuropsychological dysfunction in the PPND family with the N279K tau mutation.
The N279K mutation on the tau gene of chromosome 17 leads to an inherited condition that involves pallido-ponto-nigral degeneration (PPND). Patients with PPND develop dementia, but the pattern and onset of cognitive dysfunction has not yet been delineated. Four affected patients underwent neurocognitive evaluation within the first 2 years of PPND motor onset; one of whom underwent five serial neurocognitive evaluations, and another who was not diagnosed with PPND until the third annual evaluation. Impaired letter fluency was found in the early stages of PPND and was also shown to precede the onset of motor symptoms by 2 years. Trail Making A (visual scanning and motor speed) and Trail Making B (divided attention) were impaired within the first 2 years of the disease in all but one patient, but this individual showed clinically significant decline on these tasks by the third year of the disease. Learning, memory, and timed visuospatial sequencing skills were variably affected. Results reveal disproportionate frontal-executive dysfunction early in PPND disease course, a pattern similar to what has been reported in other FTDP-17 kindreds and in sporadic PSP. In addition, results suggest that letter fluency may be a sensitive predictor of incipient PPND.
Chromosomes, Human, Pair 17↗
Generation of reactive oxygen species by equine neutrophils and their effect on motility of equine spermatozoa.
Contaminating leukocytes in the ejaculate are an important source of reactive oxygen species (ROS) in human semen. When present in sufficient numbers, they can have a detrimental influence on sperm function in humans. Unfortunately, there is little published information regarding the importance of leukocytes in stallion semen. The objectives of this study were to determine the production of hydrogen peroxide (H2O2) by activated equine neutrophils and to examine the effect of this ROS production on equine sperm motility in vitro. Motile equine spermatozoa (two ejaculates each from four stallions) and peripheral blood neutrophils were isolated on discontinuous Percoll gradients, washed and resuspended in a modified Tyrode's medium. Spermatozoa (25 x 10(6)/ml) were incubated for 30 min at 38 C with neutrophils (0,0.5 x 10(6),1 x 10(6), 5 x 10(6) and 10 x 10(6)/ml) activated by either the protein kinase C agonist, 12-myristate, 13-acetate phorbol ester (PMA; 100 nM) or the leukocyte chemotactic peptide, formyl-methionyl-leucyl-phenylalanine (FMLP; 0.1 mM). Sperm motility was determined by computer-assisted semen analysis (CASA) at time 0 min (T0) and time 30 min (T30), and H2O2 was measured at T30 with the Amplex Red assay kit. At T30, there was a significant (P < 0.01) increase in H2O2 with the addition of 5 x 10 and 10 x 10(6) neutrophils/ml activated by FMLP (0.76 +/- 0.3 and 0.99 +/- 0.4 microM, respectively, versus 0.0024 +/- 0.002 microM in sperm alone), and this increase was associated with a significant (P < 0.001) decrease in total motility (52 +/- 5.1 and 48 +/- 6.0%, respectively, versus 80 +/- 4.7% in sperm alone). At T30, there was also a significant (P < 0.001) increase in H2O2 with the addition of 5 x 10(6) and 10 x 10(6) neutrophils/ml activated by PMA (1.88 +/- 0.2 and 2.07 +/- 0.3 microM, respectively, versus 0.0009 +/- 0.0006 microM in sperm alone). The results of this study demonstrate that 5 x 10(6) activated neutrophils/ml are sufficient to impair equine sperm motility in vitro.
Animals↗
Schwab & England: standardization of administration.
Explore the source record for details and available documents.
Humans↗
An expressed neo(r) cassette provides required functions of the 1gamma2b exon for class switching.
Germline CH transcripts initiate from a promoter upstream of a non-coding I exon, proceed through the switch (S) region and terminate downstream of the associated CH exons. To elucidate the role of germline transcription in Ig heavy chain class switch recombination (CSR), we used gene targeting in embryonic stem (ES) cells to replace most of the Igamma2b exon from immediately 3' of the majority of transcription initiation sites to beyond its donor splice site with a PGK-neo(r)gene inserted in the same transcriptional orientation as the endogenous unit. The mutation was introduced into both alleles of ES cell lines (referred to as gamma2-b(N/N)) and the neo(r) gene was deleted (referred to as Igamma2b-/-) by the loxP/Cre method. These mutations were assayed for effects on CSR in B cells derived via RAG-2-deficient blastocyst complementation. Igamma2b-/- B cells lacked ability to switch to IgG2b both in vivo and in vitro, and, correspondingly, showed no germline transcription through the Igamma2b exon, Sgamma2b or the Cgamma2b region. In contrast, Igamma2b(N/N) B cells switched at normal levels to IgG2b and showed substantial transcription through the Sgamma2b and Cgamma2b regions. Taken together, these results show that the Igamma2b sequences, per se, are not necessary for mediating CSR since a transcribed PGK-neo(r) gene can replace its function. However, the deleted portion of the Igamma2b exon and splice donor site apparently contain sequences necessary for efficient germline gene transcription and thus for CSR to IgG2b.
ATP-Binding Cassette Transporters↗
FK 506 'rescue' immunosuppression for obliterative bronchiolitis after lung transplantation.
PRELIMINARY EXPERIENCE: In a consecutive case series (level V evidence) involving 10 recipients of unilateral lung transplantation (LT) with bronchiolitis obliterans, in conjunction with Fujisawa protocol 93-0-003, the physiologic responses to FK 506 (tacrolimus) "rescue" immunosuppression were assessed. Recipients were 22+/-18 months post-LT and demonstrated progressive allograft dysfunction that was refractory to pulsed-dose methylprednisolone therapy. All recipients received induction immunosuppression with Minnesota antilymphocyte globulin (10 to 15 mg/kg/d) for 5 to 10 days, cyclosporine (CsA) (whole-blood Abbott TDX fluorescence polarization immunoassay (Abbott Inc, Abbott Park, IL)=600 to 800 ng/mL), azathioprine (2 mg/kg/d), and prednisone (tapered to 0.2 mg/kg/d). The "rescue" regimen consisted of oral FK 506 adjusted to maintain a whole-blood Abbott IMX microparticle enzyme immunoassay (Abbott Inc, Abbott Park, IL) of 10 to 15 ng/mL with an initial increase in prednisone (1.0 mg/kg/d) during conversion that was subsequently tapered to 0.2 mg/kg/d. Spirometry was performed monthly in accordance with accepted American Thoracic Society criteria. Recipients were classified in accordance with the International Society for Heart and Lung Transplantation (ISHLT) "Working Formulation for Standardization of Nomenclature and for Clinical Staging of Chronic Dysfunction in Lung Allografts" as stages Ib (n=2), IIb (n=4), and IIIb (n=4) upon entry to the protocol. The deltaFEV1/month relationships during CsA- and FK 506-based regimens were analyzed by linear regression and compared by signed rank test (p<0.05). RESULTS: The deltaFEV1/month slopes were -0.0687+/-0.0221 and +0.0300+/-0.033 L/mo (mean+/-SEM) for CsA and FK 506, respectively (p=0.037). Although no significant spirometric improvement was noted in most recipients, no further decline in FEV1 occurred after conversion to FK 506. Recipients with less severe chronic dysfunction (ie, obliterative bronchiolitis [OB] stages Ib and IIb) stabilized their spirometric indexes at higher levels. Two recipients with OB stage IIIb died of hypercapnic respiratory failure at 6 and 8 months after conversion. CONCLUSIONS: The deltaFEV1/mo slopes stabilized after FK 506 conversion. Earlier conversion may be beneficial in stabilizing FEV1 at a higher plateau. Significant economic impact may be anticipated with FK 506 compared to alternative cytolytic strategies for OB. However, multicenter prospective controlled investigations are necessary to further address the potential role of FK 506 after LT (level I evidence). Furthermore, the ISHLT "Staging of OB Syndrome" may have significant clinical implications vis-à-vis prognosis and potential therapies.
Bronchiolitis Obliterans↗
Differential effects of nuclear receptor corepressor (N-CoR) expression levels on retinoic acid receptor-mediated repression support the existence of dynamically regulated corepressor complexes.
Thyroid hormone and retinoic acid receptors are members of the nuclear receptor superfamily of ligand-dependent transcription factors that stimulate the transcription of target genes in the presence of activating ligands and repress transcription in their absence. Transcriptional repression by the thyroid hormone and retinoic acid receptors has been proposed to be mediated by the nuclear receptor corepressor, N-CoR, or the related factor, SMRT (silencing mediator of retinoic acid and thyroid hormone receptors). Recent studies have suggested that transcriptional repression by N-CoR involves a corepressor complex that also contains mSin3A/B and the histone deacetylase, RPD3. In this manuscript, we demonstrate that transcriptional repression by the retinoic acid receptor can be either positively or negatively regulated by changes in the levels of N-CoR expression, suggesting a relatively strict stoichiometric relationship between N-CoR and other components of the corepressor complex. Consistent with this interpretation, overexpression of several functionally defined domains of N-CoR also relieve repression by nuclear receptors. N-CoR is distributed throughout the nucleus in a nonuniform pattern, and a subpopulation becomes concentrated into several discrete dot structures when highly expressed. RPD3 is also widely distributed throughout the nucleus in a nonuniform pattern. Simultaneous imaging of RPD3 and N-CoR suggest that a subset of each of these proteins colocalize, consistent with the existence of coactivator complexes containing both proteins. In addition, a substantial fraction of both N-CoR and mSin3 A/B appear to be independently distributed. These observations suggest that interactions between RPD3 and Sin3/N-CoR complexes may be dynamically regulated.
Animals↗
Detection of coronary artery calcium by ultrafast computed tomography and its relation to clinical evidence of coronary artery disease.
Ultrafast computed tomography (CT) was used to evaluate the relation of coronary artery calcium, a marker of atherosclerosis, with a reported history of coronary artery disease (CAD) in 928 men and 290 women (mean age 53 +/- 10 years; 11% with previous CAD). Total calcium score was calculated as the sum of each lesion-specific score, calculated as the product of pixel area and density > 130 Hounsfeld units. Total score was 3 to 6 times greater (p < 0.01) and the probability of coronary artery calcium 30 to 40% greater (p < 0.01) in patients with a reported history of myocardial infarction, positive angiography, bypass surgery or angioplasty. From score cutoffs ranging from 1 to 500 for defining calcium, a negative test was accurate 93 to 98% of the time in ruling out CAD, whereas specificity increased from 43 to 93%; however, sensitivity decreased from 92 to 42%. A score cutoff of 50 showed modest sensitivity (78%) and specificity (71%); however, the predictive value for CAD from a positive test remained low (< or = 40%), regardless of score cutoff. From multiple logistic regression, total score was also an independent indicator of CAD after considering any effects due to age, sex and other CAD risk factors. Further study is needed to document the long-term prognostic use of coronary calcium screening, including criteria that best project future risk of CAD.
Adult↗
Quantitation of in vitro coronary artery calcium using ultrafast computed tomography.
Ultrafast computed tomography (UFCT) has the potential to quantify coronary hydroxyapatite (HAP). However, no definitive studies validating this technique are available. We constructed a human chest phantom model with coronary arteries represented by cylindrical holes containing: (1) calcium chloride solutions, (2) a block of HAP immersed in paraffin (without partial volume effect), and (3) HAP granules embedded in a gelatin matrix (with partial volume effect). We scanned this model to determine the relationship between measured CT number per voxel and density of the calcium per voxel. The relationships between CT number and concentration of calcium chloride was linear (r = 0.992 to 0.999). Using a commercially available standard bone mineral phantom, we were able to estimate the concentration of HAP to an accuracy from 94 to 97% when partial volume effects were absent. However, when partial volume effects were present, two methods of estimating HAP produced significant errors (1 to 384%, and 17 to 52%). We conclude that significant partial voluming errors degrade the accuracy of HAP quantitation and that further evaluation and corrections are needed before such quantitation is clinically applied.
Calcium Chloride↗
Osmotic tolerance of equine spermatozoa and the effects of soluble cryoprotectants on equine sperm motility, viability, and mitochondrial membrane potential.
Osmotic stress attributed to differences in the relative permeability of cryoprotectants, such as glycerol and water, appears to be an important factor in cryodamage. The objective of this study was to characterize the osmotic tolerance of equine spermatozoa, and to evaluate the effects of addition and removal of cryoprotectants from equine spermatozoa on their motility, and membrane and acrosomal integrity, as well as their mitochondrial membrane potential. Equine spermatozoa had a limited osmotic tolerance to anisosmotic conditions. Although the addition of increasing concentrations of glycerol decreased the motility and viability of equine spermatozoa, the rapid removal of glycerol by dilution in isosmotic media resulted in an even greater decline in motility and viability compared with spermatozoa maintained under anisosmotic conditions. Likewise, the addition and rapid removal of 1.0 M glycerol, ethylene glycol, dimethylsulfoxide, or propylene glycol resulted in a significant decline in sperm motility and viability. Among these cryoprotectants, ethylene glycol had the least detrimental effect on either viability or motility of spermatozoa following the rapid addition and removal of these cryoprotectants. These data demonstrate that equine spermatozoa have a limited osmotic tolerance compared with published reports for mouse or human spermatozoa, and appear to be more similar to boar spermatozoa in their osmotic tolerance. Of the 4 cryoprotectants evaluated in equine spermatozoa, the addition and removal of glycerol resulted in a more marked osmotic stress as indicated by alterations in motility, viability, and acrosomal integrity. These data suggest that alternative cryoprotectants should be considered for cryopreservation of equine spermatozoa in order to reduce osmotic stress associated with the addition of these agents during semen freezing.
Animals↗