The semireduced, semioxidized, and OH·-adduct radicals of bilirubin (BR) and biliverdin (BV)have been characterized using pulse radiolysis techniques. Laser flash photolysis (265-nm) of these ...pigments led to monophotonic photoionization with quantum yields of 0.08 for BR and 0.03 for BV. No evidence for triplet formation or for photoisomerization was found after 265-nm laser excitation. However, 347-nm excitation of BR in chloroform led to simultaneous photoisomerization and radical formation, but the radicals are thought to have originated from a pathway other than photoionization. The relevance of these observations to BR photoreactivity is discussed. BR radical ions in alkaline solution did not react with tryptophan (TrpH), but the semioxidized TrpH radical oxidized BR with $k=4.3\times 10^{8}\ {\rm dm}^{3}\ \text{mole}^{-1}\ {\rm sec}^{-1}$. When human serum albumin (HSA) was oxidized using radiolytically generated azide radicals, a radical transformation involving TrpH and TyrOH residues occurred with $k=3.8\times 10^{3}\ {\rm sec}^{-1}$. When BR was complexed with the protein the transformation rate was reduced to $1.6\times 10^{3}\ {\rm sec}^{-1}$. This was interpreted in terms of a conformational change in the protein. Identification of the probable residues involved provided information about the primary BR binding site which was consistent with an earlier report.
Conjugation to the small eukaryotic protein ubiquitin can functionally modify or target proteins for degradation by the proteasome. Removal of the ubiquitin modification, or deubiquitination, is ...performed by ubiquitin-specific proteases and is an important mechanism regulating this pathway. Here we describe a novel human ubiquitin-specific protease, USP3, initially identified as a partial cDNA clone similar to one of two highly conserved sequence regions common to all ubiquitin-specific proteases. We have isolated a complete USP3 cDNA clone containing both of these conserved sequence regions. The USP3 gene appears to be single copy and maps to human chromosome 15q22.3. A USP3 probe detects two mRNA transcripts, one of which corresponds in length to the cDNA. Both are expressed at low levels in all tissues examined, with highest expression in pancreas. The USP3 protein is a functional ubiquitin-specific protease in vitro, and is able to inhibit ubiquitin-dependent degradation of both an N-end Rule substrate and abnormal endogenous proteins in yeast. USP3 is also only the second known ubiquitin-specific protease capable of efficiently cleaving a ubiquitin-proline bond.
Abstract only Objective: TGFβ signaling has been shown to play a major role in the pathogenesis of Marfan syndrome (MFS), leading to a novel treatment strategy through TGFβ inhibition using losartan. ...We hypothesized that circulating TGFβ levels may be elevated in disorders that disrupt arterial wall extracellular matrix, such as the vascular form of Ehlers-Danlos syndrome (VEDS). Patients and Methods: Circulating levels of TGFβ-1 were measured in EDTA plasma of 141 patients with MFS (n=21, mean age 43±16y), VEDS (n=41, 37±13y) and controls (n=79, 48±13y) using an electrochemoluminescence platform (LLOQ 4±2.6pg/ml). Results: In keeping with prior work, this study revealed increased circulating TGFβ in patients with MFS compared to control patients (9.2±1.2ng/ml vs. 2.5±0.4ng/ml, p<0.0001). Remarkably, the levels seen in patients with VEDS were also significantly higher than controls (8.0±1.0ng/ml vs. 2.5±0.4ng/ml, p<0.0001) and statistically indistinguishable from those seen in MFS (9.2±1.2ng/ml vs. 8.0±1.0ng/ml, p=0.5). In a bivariate logistic regression model, the odds ratio was 7.5 (p=0.02, CI 1.3– 43.3) when comparing quartiles of TGFβ values in VEDS patients with age, sex and BMI matched controls. There was a non-statistically significant trend for higher TGFβ levels in patients without cardiovascular medication (MFS, 11.4±3.0ng/ml; VEDS, 8.5±1.3ng/ml) compared to patients treated with ARBs and/or ACE-Is (MFS, 6.1±1.0ng/ml; VEDS, 4.6±0.8ng/ml), whereas β-blockers appeared to have some impact on TGFβ levels in MFS (9.0±1.7ng/ml) but not in VEDS patients (8.3±1.8ng/ml). The influence of age on TGFβ levels in the controls is statistically significant but weak (r=0.3, p=0.007). In the disease groups, TGFβ is inversely related to age (MFS, r=−0.7, p<0.0001; VEDS, r=−0.1, p=0.6), which is most likely due to ascertainment bias towards a less severe phenotype in the older patients and longer duration of medical therapy, especially in the MFS population. Conclusion: Further investigation is warranted to establish the role of TGFβ signaling in the pathogenesis of VEDS. The current results may help to provide a rationale for the use of TGFβ lowering drug therapy in this patient population as it is emerging in the MFS patient population.
The association between virologic response and human immunodeficiency virus type 1 (HIV-1) subtype was investigated in 113 HIV-1–infected children randomly assigned to receive zidovudine plus ...lamivudine, zidovudine plus abacavir, or lamivudine plus abacavir in the Paediatric European Network for Treatment of AIDS (PENTA) 5 trial. Symptomatic children (n=68) also received nelfinavir; asymptomatic children (n=45) were randomly assigned to receive nelfinavir or placebo. HIV-1 subtypes A, B, C, D, F, G, H, A/E, and A/G were found in 15%, 41%, 16%, 9%, 5%, 2%, 1%, 5%, and 7% of the children, respectively. Resistance assay failure rates were higher for non-B subtypes than for B subtypes (genotype, P=.01; phenotype, P=.02). HIV-1 subtype was not associated with virologic response at 24 and 48 weeks after initiation of treatment. No differences were observed in the frequency of development of resistance mutations L90M (P=1.00) and D30N (P=.61) in B and non-B viruses. In conclusion, no evidence that subtype determined virologic response to therapy was found
Skeletal muscle has been examined in a colony of the mdx strain of myopathic mice. Sixty-five mice from 22 to 303 days of age, showed extensive and recurrent areas of necrosis and regeneration of ...muscle fibres, often accompanied by active cellular infiltration. Morphometry of the soleus muscle revealed an abnormal proportion of small and large muscle fibres; over half of the muscle fibres contained 'central' (non-peripheral) nuclei. No histochemical muscle fibre-type grouping was detected. Serum activities of muscle-derived enzymes were greatly elevated in all animals and probably reflect enzyme leakage from damaged muscle fibres. Histological evidence of a cardiomyopathy was found in 13 mice. The mdx myopathy thus shows features seen in Duchenne muscular dystrophy. Mdx differs from Duchenne dystrophy principally in that it exhibits a greater degree of compensatory muscle regeneration and an absence of fibro-fatty replacement of muscle fibres.
Purpose: To assess electrophysiological recovery in successfully treated strabismic amblyopes. Methods: Pattern reversal visual evoked potentials were recorded from 11 successfully treated strabismic ...amblyopes 7 to 11 years of age and 10 age-matched normal children using 12.5' and 50'checks. Results: Nine amblyopic eyes had recovered to a Snellen acuity of 6/6 or better, and the remaining 2 were 6/9 after patching. Comparison between the amblyopic and the fellow eyes showed significantly lower P100amplitude for the amblyopic eyes with small checks (difference –16.7%; P <.02) and significantly longer latency with larger checks difference (+5.0%; P <.02). The P100 latencies to stimulation of both the amblyopic and fellow eyes by 12.5' checks were markedly longer than in normal subjects (amblyopic eye, +11.7%, P <.0001; fellow eye, +7.7% P <.002). Conclusions: Successfully treated amblyopic eyes showed significantly longer latency than did normal eyes with small check stimulation. However, the nonamblyopic fellow eyes also showed significantly longer latency than did normal eyes, suggesting altered central processing. (J AAPOS 2002;6:389-92)
A failure of human foveal development only occurs in two genetically determined conditions; aniridia (Pax6 mutation) and albinism (tyrosinase mutation). The chiasmatic pathways from this region are ...disrupted in albinism and central retinal blood vessel patterns are abnormal. It is assumed that these three abnormalities have a common mechanism. Here we investigate whether similar abnormalities are present in subjects with aniridia. Using fundus photographs it is shown that abnormal blood vessel patterns are present in aniridia, but these significantly differ from those in albinos. Using electrophysiological techniques, abnormal hemispheric projections through the chiasm are demonstrated in albinos, but aniridics do not differ from normal subjects. These results demonstrate that although mutations in Pax6 and tyrosinase both affect central retinal development, they have a fundamentally different impact on the formation of the retinal vasculature and the projections from this region. This strongly suggests that separate mechanisms regulate the development of the central retina and decussation patterns at the optic chiasm.
This paper describes challenging requirements on the configuration service for the ATLAS experiment at CERN. It presents the status of the implementation and testing one year before the start of data ...taking, providing details of: 1. the capabilities of the underlying OKS object manager to store and to archive configuration descriptions, its user and programming interfaces; 2. the organization of configuration descriptions for different types of data taking runs and combinations of participating sub-detectors; 3. the scalable architecture to support simultaneous access to the service by thousands of processes during the online configuration stage of ATLAS; 4. the experience with the usage of the configuration service during large scale tests, test beam, commissioning and technical runs. The paper also presents pro and contra of the chosen object-oriented implementation compared with solutions based on pure relational database technologies, and explains why after several years of usage we continue with our approach.
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