[Renal angioma. Indications of selective renal angiography (2 clinical cases)].
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Biomedical subjects
Publications and source records attributed to P Roy.
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Bluetongue virus-like particles (VLPs), synthesized by coexpression of VP2, VP3, VP5, and VP7 using recombinant baculoviruses, have been examined by cryoelectron microscopy and image analysis. The 3-D reconstruction of these VLPs reveals an icosahedral structure 86 nm in diameter with essentially the same features as for the native Bluetongue virus (BTV) particle. The VLP is thus shown to contain the four constituent proteins as the native virus particle, with each of the protein positions highly occupied. Since the BTV core-like particle formed by coexpression of VP3 and VP7 lacks five VP7 trimers around each of the five-fold axes, it appears that the presence of the outer capsid proteins VP2 and VP5 is necessary for the adhesion of these VP7 trimers around the five-fold axes. The observed spontaneous formation of complete VLP in the absence of the BTV nonstructural proteins implies that the nonstructural proteins are not necessary for the formation of the double-shelled viral capsid. However, the nonstructural proteins may be involved in different aspects of genome replication and packaging.
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African horse sickness virus (AHSV), of which there are nine serotypes (AHSV-1, -2, etc.), is a member of Orbivirus genus within the Reoviridae family. Both in morphology and molecular constituents AHSV particles are comparable to those of bluetongue virus (BTV), the prototype virus of the genus. The two viruses have seven structural proteins (VP1-7) organized in two layered capsid. The outer capsid is composed of VP2 and VP5. The inner capsid, or core, is composed of two major proteins, VP3 and VP7, and three minor proteins, VP1, VP4 and VP6. Within the core is the virus genome. This genome consists of 10 double-stranded (ds)RNA segments of different sizes, three large, designated L1-L3, three medium, M4-M6, and four small, S7-S10. In addition to the seven structural proteins that are coded by seven of the RNA species, four non-structural proteins, NS1, NS2, NS3 and NS3A, are coded by three RNA segments, M5, S8 and S10. The two smallest proteins (NS3 and NS3A) are synthesized by the S10 RNA segment, probably from different in-frame translation initiation codons. Nucleotide sequences of eight RNA segments (L2, L3, M4, M5, M6, S7, S8 and S10) and the predicted amino acid sequences of the encoded gene products are also available, mainly representing one serotype, AHSV-4. In this review the properties of the AHSV genes and gene products are discussed. The sequence and hybridization analyses of the different AHSV dsRNA segments indicate that the segments that code for the core proteins, as well as those that code for NS1 and NS2 proteins, are highly conserved between the different virus serotypes. However, the RNA encoding NS3 and NS3A, and the two segments encoding the outer capsid proteins, are more variable between the AHSV serotypes. A close phylogenetic relationship between AHSV, BTV and epizootic haemorrhagic disease virus (EHDV), three Culicoides-transmitted orbiviruses, has been revealed when the equivalent sequences of genes and gene products are compared. Recently, the four major AHSV capsid proteins have been expressed using recombinant baculoviruses. Biochemically and antigenically these proteins are similar to the authentic proteins. Since the AHSV VP7 protein is highly conserved among the different serotypes, it has been utilized as a diagnostic reagent. The expressed VP7 protein has also been purified to homogeneity and crystallized for three-dimensional X-ray analysis.(ABSTRACT TRUNCATED AT 400 WORDS)
Bluetongue virus (BTV) forms tubules in infected mammalian cells. These tubules are virally encoded entities which can be formed with only one protein, NS1. The NS1 protein does not form a part of virus particles, and its function in viral infection is uncertain. Expression of the NS1 gene in insect cells by recombinant baculovirus yields high amounts of NS1 tubules (ca. 50% of cellular proteins) which are morphologically and immunologically similar to authentic BTV NS1 and can be isolated to about 90% purity. The structure of these synthetic NS1 tubules was investigated by cryoelectron microscopy. NS1 tubules are on average 52.3 nm in diameter and up to 100 nm long. The structure of their helical surface lattice has been determined using computer image processing to a resolution of 40 A. The NS1 protein is about 5.3 nm in diameter and forms a dimer-like structure, so that the tubules are composed of helically coiled ribbons of NS1 "dimers," with 21 or 22 dimers per turn. The surface lattice displays P2 symmetry and forms a one-start helix with a pitch of 9.1 nm. The NS1 tubules exist in two slightly different pH-dependent conformational states.
The structure of the bluetongue virus (BTV) particle, determined by cryoelectron microscopy and image analysis, reveals a well-ordered outer shell which differs markedly from other known Reoviridae. The inner shell is known to have an icosahedral structure with 260 triangular spikes of VP7 trimers arranged on a T = 13,l lattice. The outer shell is seen to consist of 120 globular regions (possibly VP5), which sit neatly on each of the six-membered rings of VP7 trimers. "Sail"-shaped spikes located above 180 of the VP7 trimers form 60 triskelion-type motifs which cover all but 20 of the VP7 trimers. These spikes are possibly the hemagglutinating protein VP2 which contains a virus neutralization epitope. Thus, VP2 and VP5 together form a continuous layer around the inner shell except for holes on the 5-fold axis.
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The steroidogenic acute regulatory (StAR) protein, a novel phosphoprotein, is a crucial factor involved in intramitochondrial cholesterol transportation, the rate-limiting step in steroidogenesis. The present investigations were undertaken to elucidate involvement of thyroid hormone and StAR protein in the regulation of steroidogenesis in mouse Leydig cells. Treatment of cells with triiodothyronine (T(3)) coordinately augmented the levels of StAR protein, StAR mRNA, and steroid production, and these responses were progressively dependent on expression of steroidogenic factor 1 (SF-1). With regard to steroidogenesis and StAR expression, the T(3) response requires both on-going mRNA and protein synthesis. In addition, the effects of T(3) were acutely modulated at the steroidogenic machinery and luteinizing hormone receptor (LHR) function, while these levels were suppressed following longer periods of exposure to T(3). Furthermore, the inhibition of SF-1 expression by DAX-1 markedly abolished T(3)-mediated StAR expression in a time frame, which was consistent with decreased steroid biosynthesis. Specific involvement of SF-1 was further confirmed by assessing the 5'-flanking region of the mouse StAR gene, which identified a region between -254 and -110 bp that was essential for T(3) function. Importantly, it was found that the SF-1 binding site at position -135 bp of the 5'-flanking region was greatly involved in T(3)-mediated reporter activity. Electrophoretic mobility shift assays (EMSA) also demonstrated involvement of SF-1 in T(3) function. The relevance of T(3)-mediated LHR function was investigated in mice rendered hypo-and hyperthyroid, which accounted for up-regulation in the former and down-regulation in the latter group, respectively. These findings demonstrate a key role of thyroid hormone in maintaining mouse Leydig cell function, where thyroid hormone and StAR protein coordinately regulate steroid hormone biosynthesis.
PURPOSE: To compare the efficacy and safety of streptokinase (SK) and urokinase (UK) in the treatment of local thrombolysis. PATIENTS AND METHODS: Over a 24-month period, 40 patients with 45 lower limb arterial occlusions of less than 45 days duration underwent intraarterial fibrinolysis. Twenty occlusions were treated with recombinant UK and tissue culture-derived UK, and 25 occlusions were treated with SK. The study was retrospective, but the two groups were very homogeneous in terms of vascular surgical history, medical risk factors, and occlusion characteristics. RESULTS: Complete lysis (95% or more) was achieved in 84% of SK infusions and 89% of UK infusions. Endoluminal and surgical interventions as well as clinical outcomes of SK and UK treatment were comparable. However, infusion time was significantly longer for SK treatment: 28.5 hours versus 19.1 hours for UK treatment (P = .035). Complication rates were not statistically significantly different. Average length of stay in the intensive care unit was identical (2.2 days) for both groups, and the difference in hospital stay was not statistically significant (7.7 days for SK vs 8.7 days for UK). CONCLUSION: At the concentrations and doses used, the efficacy and safety of SK and UK were comparable, despite longer SK infusion time.
BACKGROUND: Recent research has shown that phonological awareness therapy can improve speech production in children with expressive phonological disorders. This approach may be appealing to clinicians as the therapy may also benefit the children's general phonological abilities and lead to gains in their literacy skills. AIMS: To examine the effectiveness of phonological awareness therapy under conditions more similar to those prevailing in many speech and language therapy clinics. Children were treated in small groups and less intensive therapy was offered than in previous studies. METHODS & PROCEDURES: Twenty children were randomly assigned to treated and untreated groups. A pre-/post-test design was used to monitor their progress in phonological awareness, literacy and speech production. Children were treated in groups of three. They received 12 hours of therapy. OUTCOMES & RESULTS: Comparisons of the groups showed that the treated group made significantly greater gains in phonological awareness. However, differences between the groups in the measures of literacy and speech production were smaller and non-significant. Considerable variation was detected in the response of individual children to the therapy. CONCLUSIONS: The results show the effectiveness of phonological awareness therapy in benefiting children's general phonological skills. However, the comparison of these and previous findings suggest that children may require more therapy than is often available if literacy and speech production are also to benefit. Further research is required to confirm the duration and intensity of therapy required. Until such information is available, clinicians might want to take a cautious approach and combine therapies that target phonological awareness with more traditional approaches, that target speech production more directly.
BACKGROUND. Managed care rewards those individuals and institutions capable of achieving superior patient outcomes while making wise use of limited resources. However, studies of patient outcomes under these circumstances are lacking. We sought to investigate whether decreasing length of stay and limiting resource utilization had a negative effect on objective measurements of patient outcome for patients with congestive heart failure. METHODS. Guided by studies of evidence-based medicine, a multidisciplinary team developed and implemented a clinical care multidisciplinary action plan for the inpatient management of congestive heart failure. This provided practitioners with a target length of hospital stay, projections for daily improvements based on intervention, guidelines for diagnostic studies and medical therapy, early identification of patients with special discharge needs, and intensive patient education. RESULTS. Shorter lengths of stay for patients with congestive heart failure were achieved without negatively impacting on mortality or readmission rates. The study found a trend in favor of greater utilization of appropriate medical therapy despite shorter hospitalization. CONCLUSION. The use of a clinical care map for management of complex medical illnesses can be associated with shorter hospital stay without sacrificing patient outcomes. (c)2001 by CHF, Inc.
Although it is known that cells promote structural reorganization of the collagen architecture, how individual cells exert mechanical tension on the matrix is not clearly understood. In the present study we have investigated the mechanical interaction of individual corneal fibroblasts with a collagen matrix using an improved version of our previously described in vitro force-measurement system (Roy, P. et al. Exp. Cell Res. 232:106-117, 1997). The elastic distortion of the collagen matrix exerted by cells was temporally recorded and analyzed using a two-dimensional finite-element model to quantify the forces exerted on the matrix. Time-lapse videomicroscopy of serum-cultured cells on the matrix for up to 6 h revealed that individual fibroblasts generated measurable tension on the matrix during pseudopodial extension and slow retraction. Fast retraction, an event observed during active cell migration, was associated with dramatic release of tension on the matrix. An apparent inverse correlation was observed between cell translocation and maintenance of matrix tension. Additional experiments with cells under serum-free conditions revealed that these cells fail to generate any detectable tension on the matrix despite undergoing filopodial extension and retraction. Since serum-free cells do not form focal adhesions or stress fibers, these experimental data suggest that contractility of nonmotile cells, coupled with strong cell-matrix adhesion, is the most favorable mechanism of generating and maintaining tension on the extracellular matrix.
Rabbit neutral endopeptidase 24.11 (NEP) is a type II membrane protein with a positively charged 27 amino acid residue NH2-terminal cytoplasmic domain, a 20 amino acid residue hydrophobic signal peptide/membrane anchor domain, and a large catalytic COOH-terminal domain exposed on the exoplasmic side of the membrane. To study the role of the cytosolic domain in anchoring NEP in the plasma membrane, we constructed two mutants in which this cytosolic domain was deleted. In the first mutant (NEP delta cyto), a Glu residue was present in NH2-terminus, while a Lys residue was substituted at the same position in the second mutant (NEP delta cyto(K)). To better understand the interaction of these mutants with the rough endoplasmic reticulum membrane, the mutated NEP cDNAs were transcribed and translated in vitro in the presence of microsomal membranes. Our studies showed that deletion of the hydrophillic cytosolic domain affects translocation of the NEP polypeptide chain. Substitution of a positively charged Lys residue for the Glu residue at the NH2-terminus of the deletion mutant only partly restored translocation of the polypeptide chain. Furthermore, carbonate extraction and trypsin digestion of the microsomal membranes indicated that the deletion mutants are inserted in the microsomal membranes as type III membrane proteins with their COOH-terminal domain exposed on the exterior of the microsomes. Thus, efficient translocation is dependent on the presence of a charged cytoplasmic domain.
To elucidate the sources of free catecholamines (CA) and their sulfates in hyperadrenergic essential hypertensives (EH), their arteriovenous differences were determined radioenzymatically and by sulfatase hydrolysis (with correction for cross-contamination) across several organs and regions in 16 hyperadrenergic essential hypertensive patients. Comparison with arterial concentrations showed that: the adrenal venous outflow contains 240 times more free epinephrine (E), 55 times more free norepinephrine (NE), and 7 times more free dopamine (DA) concentrations, but E, NE, and DA sulfates are not different; free E concentrations are lower in the peripheral venous blood; NE sulfate concentrations are higher in the superior vena cava (p less than 0.05 for all differences noted). The data suggest the following conclusions for hyperadrenergic EH patients: with the exception of NE sulfate added into the superior vena cava region, no other organ or region can be associated with a net DA or NE sulfate release. The proportional adrenal vein concentrations of DA:NE:E are approximately 1:10:50, which are very close to those seen in other studies performed under different degrees of stress. Free E is extracted in peripheral tissues. The DA surges in hyperadrenergic EH patients probably result from the pulsatile, predominantly adrenal, release of free DA.
The pathogenicity of one isolate of Salmonella typhimurium, four isolates of Salmonella heidelberg, three isolates of Salmonella kentucky, two isolates of Salmonella montevideo, one isolate of Salmonella hadar, and two isolates of Salmonella enteritidis (SE), one belonging to phage type (PT)13a and the other to PT34, was investigated in specific-pathogen-free chicks. Three hundred eighty-four chicks were separated into 16 equal groups of 24 chicks. Thirteen groups were inoculated individually with 0.5 ml of broth culture containing 1 x 10(7) colony-forming units (CFU) of either S. typhimurium (one source), S. heidelberg (four sources), S. montevideo (two sources), S. hadar (one source), S. kentucky (three sources), SE PT 13a (one source) or SE PT 34 (one source) by crop gavage. Two groups of 24 chicks were inoculated in the same way with 1 x 10(7) CFU of SE PT4 (chicken-CA) and Salmonella pullorum. Another group of 24 chicks was kept as an uninoculated control group. The chicks were observed daily for clinical signs and mortality. Isolation of salmonella was done from different organs at 7 and 28 days postinoculation (DPI). All the chicks were weighed individually at 7, 14, 21, and 28 DPI. Two chicks chosen at random from each group were euthanatized and necropsied at 7 and 14 DPI and all the remaining live chickens, at 28 DPI. Selected tissues were taken for histopathology at 7 and 14 DPI. Dead chicks were examined for gross lesions and tissues were collected for histopathology. Chicks inoculated with S. pullorum had the highest mortality (66.66%), followed by S. typhimurium (33.33%). Chicks inoculated with S. heidelberg (00-1105-2) and SE PT4 (chicken-CA) had 12.5% mortality and 8.3% mortality, respectively, with SE PT 13a. Ceca were 100% positive for salmonellae at acute or chronic infection compared with other organs. Mean body weight reduction ranged from 0.67% (inoculated with S. kentucky 00-926-2) to 33.23% (inoculated with S. typhimurium 00-372) in the inoculated groups at different weeks compared with uninoculated controls. Gross and microscopic lesions included peritonitis, perihepatitis, yolk sac infection, typhilitis, pneumonia, and enteritis in some groups, especially those inoculated with S. typhimurium, S. heidelberg (00-1 105-2), SE PT4 (chicken-CA), and S. pullorum.
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Analysis of records of admitted children (0-12 years) in Chittaranjan Sishusadan Hospital, Calcutta during 1987 revealed that acute respiratory infections contributed 20.1% of all admissions. Lower respiratory infections were common. 93.7% of children were below 5 years of age. Case fatality rate due to ARI was the highest (17.6%) during infancy. Higher number of admissions were observed during the monsoon months.
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