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PubMed1986

CAT vectors for analysis of eukaryotic promoters and enhancers.

We have constructed two sets of plasmids for analysis of factors affecting mammalian gene expression. The pOCAT series contains a bacterial chloramphenicol-resistance expression unit (cat) and no eukaryotic promoter. The pUTKAT series contains the same cat unit under the control of the thymidine-kinase promoter of Herpes simplex virus. These plasmids are designed for testing effects of inserted regulatory elements on cat expression after transient transfection of mammalian cells in culture. We demonstrate here that the pOCAT series is useful for studying activities of inserted eukaryotic promoters, and the pUTKAT series is useful for studying activities of inserted eukaryotic enhancers.

Acetyltransferases↗
PubMed1996

ROC assessment of compressed wrist radiographs.

The aim of this paper is to validate a compression scheme applied on a medical image database of digitized wrist radiographs. The compression scheme adapts itself to local statistical properties of the images. The diagnostic quality of the reconstructed images is evaluated using a ROC protocol involving five medical experts. The results of this evaluation enable us to validate the compression scheme on this database with a compression ratio of 40 (0.2 bits per pixel).

Humans↗
PubMedDate not supplied

SAR reduced pulse sequences.

Three techniques were considered for reducing the RF (radiofrequency) power deposition in the body while maintaining scan time efficiency: reducing the RF peak amplitude while increasing the pulse width, substituting gradient echoes for spin echoes, and reducing the flip angle of the phase reversal pulse. The use of gradient echoes was found to be the most efficient means to reduce the power delivered to the patient and to obtain rapid data acquisition. The effect upon SAR (specific absorption rate) and SNR (signal-to-noise ratio) was demonstrated on a phantom when the phase reversal pulse was reduced from the standard 180 degrees to 90 degrees. Data in the body indicated a fairly constant SNR down to a refocusing flip angle between 110 degrees and 135 degrees. An initial clinical evaluation was performed at three institutions using the method of reducing the flip angle of the phase reversal pulse. The scan with theta = 120 degrees was rated by readers in a blinded study as having acceptable diagnostic image quality while the 135 degrees scan had comparable image quality to a conventional 90 degrees - 180 degrees pulse sequence. The use of reduced phase reversal pulses was seen as an efficient protocol to obtain T1-weighted images at rapid data rates while reducing the power delivered to the body by about 40%.

Humans↗
PubMed1990

Truncated sinc slice excitation for 31P spectroscopic imaging.

The shortest possible delay (Td) between slice selection and data acquisition is important for producing high quality 31P spectra. In single slice multivoxel spectroscopic imaging, conventional excitation using sinc-shaped rf pulses within typical gradient limitations can have values of Td that lead to significant spectral distortion and loss of signal. Truncated sinc excitation, which ends the excitation close to the center of the main rf lobe has been suggested for MR angiographic applications to produce short values of Td. In this work, the slice profiles, spectral signal-to-noise ratio (SNR) and spectral distortions are compared using the minimum delay achievable on a commercial MRI system for conventional 'sinc' rf excitation and truncated sinc excitation. Slice profiles are calculated using the Bloch equations and measured with a phantom. SNR and spectral distortions are evaluated from whole slice spectra on a human volunteer. On an MRI system with 1 G/cm gradients (0.5 msec risetime), for a 2.5-cm slice at 31P frequencies, conventional excitation can be adjusted to achieve Td = 2.5 msec while truncated sinc excitation yields Td = 1.5 msec. The truncated sinc excitation's shorter value of Td leads to much smaller spectral distortions, but its slice profile has "dispersive tails" which increase as more of the rf is truncated. Slice profile corrected SNR for the beta-ATP peak of 31P on a human volunteer is equivalent for both sequences while, qualitatively, in the PDE region the truncated sinc approach has improved SNR.

Brain↗
PubMed1990

Tissue distribution of 131I radiolabeled transferrin in the athymic nude mouse: localization of a human colon adenocarcinoma HT-29 xenograft.

The tissue distribution of 131I-transferrin (131I-Tf) was studied in athymic nude mice having s.c. human colonic adenocarcinoma HT-29 xenografts. Four days after 131I-Tf injection, the 131I-specific activity measured in the HT-29 tumor, i.e. amount of radioactivity per gram of fresh tissue, represented 0.31 +/- 0.09% of the injected radioactivity and was 1.90 fold more than that measured in the murine colon (P less than 0.05). After correction for intravascular 131I-Tf as estimated by means of 99mTc-Sn in vivo labeling of red blood cells, the 131I specific activity observed in the HT-29 tumor was 7.21 fold more than that observed in the murine colon. This subtracting method enabled us to localize a HT-29 tumor xenograft by gamma scintigraphy of the entire animal and demonstrated that 131I-Tf could be a non-specific but potent marker for human colon cancer.

Adenocarcinoma↗
PubMed1992

Atrial natriuretic peptide during water deprivation or hemorrhage in rats. Relationship with arginine vasopressin and osmolarity.

The concentrations of atrial natriuretic peptide (ANP) in atria, hypothalami and plasma were investigated in relation to the variations of the plasma endogenous immunoreactive arginine vasopressin (Ir-AVP) during water deprivation or hemorrhage in normal conscious Wistar rats. Furthermore, the in vitro and in vivo effect of extracellular hyperosmolarity on ANP release from right atrium and hypothalamus was examined. Water deprivation elevated circulating immunoreactive ANP (Ir-ANP: pg/ml) to 153 +/- 7 (24 h); 174 +/- 1 (48 h) from the control level (109.6 +/- 7.8). This increase in Ir-ANP concentration which correlated with atrial (r = -0.93) or hypothalamic (r = -0.87) Ir-ANP content decrease, was associated with significantly enhanced levels of plasma Ir-AVP, plasma sodium, osmolarity and hematocrit. An acute volume depletion by hemorrhage significantly reduced plasma Ir-ANP (67 +/- 8.4 pg/ml) from the sham operated level (140 +/- 18 pg/ml). Plasma Ir-AVP was elevated dramatically (207.4 +/- 53.4 pg/ml) compared with the sham operated level (8.8 +/- 2.6 pg/ml). These results, indicating the lack of correlation between plasma Ir-ANP and Ir-AVP in vivo, suggest that the ANP secretion, which is regulated mainly by plasma volume, may be modulated by a change in plasma osmolarity. Extracellular hyperosmolarity stimulated the ANP release from superfused sliced normal rat atria and hypothalami.

Animals↗
PubMed1995

[Treatment of atopic dermatitis].

There are three components in the treatment of atopic dermatitis: 1) a general treatment (mainly antibiotherapy directed towards Staphylococcus aureus during acute phases), 2) local treatment (local antiseptics, local steroids, emollients), 3) practical advice. In addition, it is of great importance that clear and complete information on the illness should be given to the parents.

Administration, Topical↗
PubMed1996

[Dermatitis herpetiformis occuring in patients with celiac disease in childhood].

BACKGROUND: Dermatitis herpetiformis (DH) is a chronic papulovesicular immune-mediated disorder associated with gluten-sensitive enteropathy. We report eight cases in which DH appeared many years after celiac disease (CD) in child. PATIENTS AND METHODS: The diagnosis of CD was based on histological features of total or subtotal villous atrophy, full remission after withdrawal of gluten from the diet, and eventually circulating antibodies (IgA gliadin, antireticulin and antiendomysium) at the time of diagnosis and their disappearance under gluten-free diet. The diagnosis of DH was made from clinical findings, histological examination of the involved skin and direct immunofluorescence microscopy of normal or perilesional skin. HLA class II typing was performed in five patients. DRB1, DQA1, DQB1 and DBP1 alleles were studied. RESULTS: DH appeared between 3 and 22 years after the initial diagnosis of CD. Five patients did not show at that time any digestive symptoms. In three cases, a break in the gluten-free diet or a recent revival of the normal diet preceded the rash. In only one case, DH appeared while the patient was under gluten-free diet. In three patients, the rash appeared many years after the gluten-free diet had been stopped. Phenotype DR3 and/or DR7 of the celiac disease could be found in four of the five patients studied; three of them were found to bear DQW2. The DR2 allele was not found in any of the five tested patients. DISCUSSION: These eight cases illustrate the absence of precise nosological barrier between gluten-sensitive enteropathy of the DH and that observed in CD. The presence of the DR7 allele, and especially the absence of the DR2 allele, could explain the particularly severe and symptomatic course of the enteropathy in these patients. The delay in the appearance of DH, after a very variable period of normal diet, could correspond to the necessary time for progressive accumulation of IgA (or immune complex IgA-gluten) in the skin after a digestive sensitization to gluten. The preventive role of gluten-free diet is thus probable. CONCLUSION: CD and DH likely correspond to two different stages of the same disease, thus requiring a prolonged follow-up of both digestive and skin tissues. Long-term eviction of gluten to prevent eventual DH must be balanced with the demand and the cost of such a diet.

Celiac Disease↗
PubMed1991

In vitro effect of synthetic progestogens on estrone sulfatase activity in human breast carcinoma.

The effect of progesterone and nine synthetic progestogens on the activity rate of microsome estrone sulfatase obtained from human breast carcinoma tissues was studied. The progestogens were classified into three groups: group I with a strict inhibitor effect: demegestone and chlormadinone acetate; group II with a strict activator effect: medroxyprogesterone acetate, quingestanol acetate, lynestrenol and progesterone and group III with a nonsignificant effect: dydrogesterone, promegestone, norgestrel and danazol. Demegestone was the most potent inhibitor and medroxyprogesterone acetate and quingestanol acetate had the highest activator effect. The effect of Triton X-100, a nonionic detergent, was also tested. This detergent consistently increased the microsome estrone sulfatase activity. A comparison was made between the effects of demegestone, medroxyprogesterone acetate and danazol on estrone sulfatase activity measured with or without Triton X-100 in the incubation medium. The presence of the detergent modified the progestogen action. Our results suggest that synthetic progestogens can influence the estrone sulfatase activity measured in human breast carcinoma tissues. However, the effect of progestogens was dependent on experimental conditions. Progestogens such as demegestone and chlormadinone acetate which inhibited estrone sulfatase activity in intact preparations, can reduce the intracellular production of biological active estrogen via the sulfatase pathway.

Breast Neoplasms↗
PubMed1992

Identification of 2 alpha-hydroxy-4-pregnene-3,20-dione in human pregnancy urine.

2 alpha-Hydroxyprogesterone (2 alpha-hydroxy-4-pregnene-3,20-dione) was identified in human late pregnancy urine by liquid-gel chromatography, GLC and GC-MS. In addition, the following 2-hydroxylated C21 steroids were found and identified as 2 zeta-hydroxy-5 zeta-pregnane-3,20-dione, 2 zeta,20 zeta-dihydroxy-4-pregnen-3-one, 2 alpha,3 alpha-dihydroxy-5 alpha- (and 5 beta)-pregnan-20-one, two isomers of pregnane-2,3,20-triol and 2 zeta,3 zeta,16 zeta-trihydroxy-5 zeta-pregnan-20-one.

Chromatography, Gel↗
PubMed2006

Rationale and design of ACTIVE: the atrial fibrillation clopidogrel trial with irbesartan for prevention of vascular events.

BACKGROUND: Atrial fibrillation (AF) is the most frequently occurring cardiac arrhythmia with often serious clinical consequences. Many patients have contraindications to anticoagulation, and it is often underused in clinical practice. The addition of clopidogrel to aspirin (ASA) has been shown to reduce vascular events in a number of high-risk populations. Irbesartan is an angiotensin receptor-blocking agent that reduces blood pressure and has other vascular protective effects. METHODS AND RESULTS: ACTIVE W is a noninferiority trial of clopidogrel plus ASA versus oral anticoagulation in patients with AF and at least 1 risk factor for stroke. ACTIVE A is a double-blind, placebo-controlled trial of clopidogrel in patients with AF and with at least 1 risk factor for stroke who receive ASA because they have a contraindication for oral anticoagulation or because they are unwilling to take an oral anticoagulant. ACTIVE I is a partial factorial, double-blind, placebo-controlled trial of irbesartan in patients participating in ACTIVE A or ACTIVE W. The primary outcomes of these studies are composites of vascular events. A total of 14000 patients will be enrolled in these trials. CONCLUSIONS: ACTIVE is the largest trial yet conducted in AF. Its results will lead to a new understanding of the role of combined antiplatelet therapy and the role of blood pressure lowering with an angiotensin II receptor blocker in patients with AF.

Aged↗
PubMed2005

Heterogeneity in 1H-MRS profiles of presymptomatic and early manifest Huntington's disease.

OBJECTIVE: To evaluate (1)H-MRS profiles of the putamen in presymptomatic and manifest Huntington's disease (HD) patients for spectroscopic markers that are reliable, consistent signs of early pathology and to look for hemispheric differences as signs of use activation in an accelerated degradative process of the dominant hemisphere. METHODS: A short echo time Point RESolved Spectroscopy (PRESS) spectroscopic imaging study was performed at low field (0.5 Tesla, T) on 27 right-handed patients (17 presymptomatic gene carriers and 10 manifest patients of less than 3 years from clinical onset) and 10 right-handed normal volunteers. Spectra from individual voxels (0.56 cm(3)) in the putamen were selected for analysis. Resonance areas of peaks were normalized to water as a concentration standard. Interhemispheric comparisons were made in individuals in all three groups to look for hemispheric differences. RESULTS: Two presymptomatic patients showed normal spectra but all other HD patients displayed some combination of reduced N-acetylaspartate (NAA), enhanced glutamate/glutamine (Glx) activity, and lactate (Lac) elevations or reduced creatine (Cr). Rather than showing any one metabolite as pathognomonic of early change, spectroscopic profiles showed heterogeneity between HD patients. Low creatine was common in the presymptomatic but not in the manifest group. Hemispheric ratios of abnormal metabolites showed lower values of NAA and Glx in the dominant hemisphere in all three groups but values of creatine were selectively lower in the dominant hemisphere of only the presymptomatic patients. Lac was elevated in both hemispheres but less so in the dominant hemisphere in all HD patients. CONCLUSIONS: (1)H-MRS profiles from the putamen of presymptomatic and manifest patients reflect heterogeneity in pathophysiology. With the possible exception of low creatine in presymptomatic patients (1)H-MRS spectra are not suggestive of hemispheric differences supportive of an overall accelerated degradative process in the dominant hemisphere.

Adult↗
PubMed2006

Structural and antitumor properties of the YSNSG cyclopeptide derived from tumstatin.

We previously demonstrated that the NC1[alpha3(IV)185-191] CNYYSNS peptide inhibited in vivo tumor progression. The YSNS motif formed a beta turn crucial for biological activity. The aim of the present study was to design a YSNSG cyclopeptide with a constrained beta turn on the YSNS residues more stable than CNYYSNS. By nuclear magnetic resonance and molecular modeling, we demonstrated that the YSNSG cyclopeptide actually adopted the expected beta-turn conformation. It promoted melanoma cell adhesion and prevented their adhesion to the native peptide. It inhibited in vitro cell proliferation and migration through Matrigel by downregulating proteolytic cascades. Moreover, intraperitoneal administration of the YSNSG cyclopeptide inhibited melanoma progression far more efficiently than the native peptide. The increased solubility and stability at low pH of the YSNSG cyclopeptide suggest this peptide as a potent antitumor therapeutic agent.

Animals↗
PubMed2006

Characterisation of Ercc1 deficiency in the liver and in conditional Ercc1-deficient primary hepatocytes in vitro.

The ERCC1/XPF complex is responsible for incision at the 5' side of the lesion during nucleotide excision repair and is also involved in homologous recombination and interstrand cross-link repair. The aim of the current study was to set up a better model for examination of Ercc1 deficiency in the murine liver and to determine the DNA lesions responsible for the premature polyploidy observed. We used the Cre/lox system with an adenovirus carrying Cre recombinase to conditionally induce Ercc1 deficiency in murine hepatocytes in vitro. Increased levels of apoptosis were apparent in our Ercc1-deficient cultures, both spontaneously and after UV irradiation and oxidative DNA damage. Increased apoptosis was also observed in simple Ercc1-deficient livers and the time course of the development of polyploidy was characterised. Livers from simple Ercc1 knockout mice contained mitochondria with disrupted outer membranes. Lipid accumulation was observed in older Ercc1-deficient hepatocyte cultures and in young Ercc1-deficient and wild-type livers. Lipids disappeared from the wild-type livers with age, but persisted in Ercc1-deficient livers, suggesting that a reduced ability to repair oxidative DNA damage and a malfunction of oxidative pathways could be responsible for the Ercc1-deficient liver phenotype. Real-time RT-PCR was used to determine differences in expression of cell cycle regulation and survival genes between Ercc1-deficient and control livers. Higher mRNA levels of Igfbp2, a possible marker for polyploidy, and p21 were detected in Ercc1-deficient livers. The pro-apoptotic factor, Bax, showed increased levels of mRNA expression in young Ercc1-deficient livers. However, no elevation in the levels of reactive oxygen species, or of malondialdehyde DNA adducts, a product of oxidative DNA damage, were found in Ercc1-deficient liver and no elevated levels of genes involved in the oxidative damage response were seen.

Animals↗
PubMed2004

Two FHA domains on an ABC transporter, Rv1747, mediate its phosphorylation by PknF, a Ser/Thr protein kinase from Mycobacterium tuberculosis.

Bacterial genomics have revealed the widespread occurrence of eukaryotic-like protein kinases in prokaryotes, but little is known about their regulation, endogenous substrates, and physiological role. The present study concerns one of these enzymes, the serine/threonine protein kinase PknF from Mycobacterium tuberculosis. It is shown that, in addition to its autokinase activity, PknF is able to phosphorylate Rv1747, a newly described ABC transporter. This reaction appears to involve two FHA domains of Rv1747. It is suggested that recruitment and phosphorylation of Rv1747 depend on the interaction between its two non-redundant FHA domains and the autophosphorylated form of PknF.

ATP-Binding Cassette Transporters↗