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M Mandel

Publications and source records attributed to M Mandel.

215 records · Page 12Linked to original sources
PubMedDate not supplied

On the feasibility of MRI-guided focused ultrasound for local induction of gene expression.

Gene therapy is a promising approach to the treatment of many forms of disease, including cancer. Of critical concern in its implementation is the ability to control the location, duration, and level of expression of the therapeutic gene. Here, we propose the use of local heat in combination with a heat-sensitive promoter to help accomplish this. Certain members of the family of heat shock protein (hsp) promoters display a regulation that depends strongly on temperature. We present a study of natural hsp70 induction in rat leg by MRI-guided focused ultrasound to investigate the hsp70 promoter as a possible candidate for use in control of gene expression with local heat. A temperature increase of 5-8 degrees C in the focal region for 45 minutes led to a differential expression of the hsp70 mRNA between the focal region and the surrounding tissue ranging from a factor of 3 to 67.

Animals↗
PubMedDate not supplied

[Bacillus gordonae sp. nov., a new species belonging to the second morphological group, degrading various aromatic compounds].

Thirty strains were isolated from pasteurized soil samples by enrichment culture in aerobiosis at 32 degrees C in a minimal medium containing one of the following compounds as sole source of carbon and energy: quinate, p-hydroxybenzoate, phthalate, isophthalate or trimellitate. These bacteria were rods (0.8 X 2-7 micron), motile by peritrichous flagella. Endospores were oval (1.4-1.8 X 2 micron) and distinctly swelled the sporangia. The Gram reaction was variable but the Gram type was positive. Colonies were smaller on peptone (0.4%) agar than on minimal salts-glucose (0.2%) agar. The following characters were always present: growth in the presence of lysozyme, cytochrome c oxidase, catalase, nitrate assimilation, urease, amylase and L-glutamate dehydrogenase. The cells contained glycogen. In anaerobiosis, glucose was not fermented and nitrate was not used as a respiratory acceptor of electrons. Of 215 substrates tested, 31 (including 9 aromatic compounds) were used as sole carbon and energy sources by all 30 strains, and 38 substrates (including 13 aromatic compounds) were used by only some of them; 146 substrates (including 49 aromatic compounds) were not used by any of the 30 strains. No amino acid could be used as sole carbon and energy source. Numerical analysis of the 30 strains showed an aggregate cluster made of 5 phena. The mean G + C content of the DNA was 55 +/- 0.6 mol %. The described bacteria are clearly different from the 2 known species of the second morphological group which cannot ferment carbohydrates: Bacillus brevis and B. azotoformans. Strain Q1 (ATCC 29948) is the holotype of Bacillus gordonae sp. nov.

Bacillus↗
PubMedDate not supplied

Theoretical determination of helix-coil parameter sigma from a model of partly helical polypeptide chain.

The Zimm and Bragg parameter sigma is calculated numerically for poly(L-alanine), polyglycine, and the copolymers of L-alanine and glycine using the molecular theory of s and sigma as developed by Go, Go, and Scheraga in a modified formulation. In this formulation, sigma is obtained from the partition function of the whole chain in the helix-coil transition region and represents therefore the contributions from the ends of helical and coil sequences and from the interactions between atoms in a coil sequence with those in the neighboring helical sequence. When the parameter sigma is calculated numerically from a hard-sphere potential, it appears that steric intractions between atoms in the coil sequence with atoms in the neighboring helical sequence, which have been neglected in previous calculations, contribute significantly to the value of sigma. Owing to these interactions the entropy of the coil sequence as well as sigma decrease, but the decrease of sigma is larger in poly(L-alanine) than in polyglycine, because of the higher flexibility of the monomer in polyglycine. The numerical value of sigma for polyglycine compared with that of poly(L-alanine) might be overestimated however by the model presented here due to approximations inherent in the hard-sphere treatment and because only regular helical sequences are considered.

Alanine↗
PubMedDate not supplied

Understanding autoimmune mechanisms in multiple sclerosis using gene expression microarrays: treatment effect and cytokine-related pathways.

Multiple sclerosis (MS) is a central nervous system disease in which activated autoreactive T-cells invade the blood brain barrier and initiate an inflammatory response that leads to myelin destruction and axonal loss. The etiology of MS, as well as the mechanisms associated with its unexpected onset, the unpredictable clinical course spanning decades, and the different rates of progression leading to disability over time, remains an enigma. We have applied gene expression microarrays technology in peripheral blood mononuclear cells (PBMC) to better understand MS pathogenesis and better target treatment approaches. A signature of 535 genes were found to distinguish immunomodulatory treatment effects between 13 treated and 13 untreated MS patients. In addition, the expression pattern of 1109 gene transcripts that were previously reported to significantly differentiate between MS patients and healthy subjects were further analyzed to study the effect of cytokine-related pathways on disease pathogenesis. When relative gene expression for 26 MS patients was compared to 18 healthy controls, 30 genes related to various cytokine-associated pathways were identified. These genes belong to a variety of families such as interleukins, small inducible cytokine subfamily and tumor necrosis factor ligand and receptor. Further analysis disclosed seven cytokine-associated genes within the immunomodulatory treatment signature, and two cytokine-associated genes SCYA4 (small inducible cytokine A4) and FCAR (Fc fragment of IgA, CD89) that were common to both the MS gene expression signature and the immunomodulatory treatment gene expression signature. Our results indicate that cytokine-associated genes are involved in various pathogenic pathways in MS and also related to immunomodulatory treatment effects.

Apoptosis↗
PubMedDate not supplied

Chromosomal translocation (1:13) in a case of alveolar rhabdomyosarcoma.

PURPOSE: To describe a patient with a variant translocation (1;13)(p36;q14) in an alveolar rhabdomyosarcoma and compare the clinical course with four other cases. PATIENTS AND METHODS: A 10-year-old girl presented with multiple masses involving the thigh, abdomen, chest wall, and scalp with pleural effusion and edema of the lower extremities. RESULTS: A bone marrow biopsy, aspirate, and biopsy of the thigh mass all showed tumor invasion. Histopathology and cytogenetics of the thigh mass revealed an alveolar rhabdomyosarcoma with a t(1;13)(p36q14) variant. There was no response to aggressive therapy and the patient died within 3 weeks of admission. CONCLUSION: Variant t(1;13)(p36;q14) has now been described in 5 cases of rhabdomyosarcoma, and may define a subset of patients with extensive disease at diagnosis unresponsive to current therapeutic modalities.

Child↗
PubMedDate not supplied

Helicobacter pylori-associated gastric lymphoma in a girl.

We present a case of a 14-year-old girl with gastric large cell lymphoma. The girl's lymphoma was characterized by the presence of mucosa-associated lymphoid tissue. Infection with Helicobacter pylori (HP) was ascertained at the time of diagnosis. The girl was successfully treated by a combination of chemotherapy (MACOP-B) and anti-HP drugs (omeprazole plus amoxicillin). Thrombus of the inferior vena cava, a rare complication, evolved during treatment.

Adolescent↗
PubMedDate not supplied

[Biochemical characterization of Bacillus benzoevorans sp. nov., a new filamentous, sheathed mesophilic species, degrading various aromatic acids and phenols].

The eleven strains studied were prototrophic and did not grow in media containing only 1% Bacto-peptone or Bacto-tryptone; they grew rapidly in media containing 0.4% yeast extract and 0.2% sodium acetate or benzoate. The maximal growth temperature ranged from 39 to 45 degrees C. Six aliphatic acids, four aromatic acids and five phenols were used as sole carbon and energy sources by the 11 strains. Carbohydrates and amino acids (except for glycine) were not used as carbon and energy sources. Nitrate (but not nitrite) was used anaerobically as a respiratory electron acceptor. Nitrous oxide was used and reduced to N2 by only 3 strains. The mean guanine-plus-cytosine content of the DNA was 41.3 +/- 1.1 mol %. Morphologically and nutritionally, the bacteria described are clearly different from the 5 known species of the first morphological group whose cells have a diameter greater than 1 micrometer: Bacillus megaterium, B. cereus, B. cereus var. mycoides, B. macroides, B. badius, and B. fastidiosus. Strain B1 (=CCM 3364) is the holotype of Bacillus benzoevorans sp. nov.

Bacillus↗
PubMedDate not supplied

[Taxonomic study of free nitrogen-fixing bacteria isolated from the endorhizosphere of rice].

Twenty strains of free-living N2-fixing bacteria, isolated from the endorhizosphere of rice in rice soils of Senegal, were studied on the basis of 259 morphological, physiological, biochemical and nutritional characters. Half of them were Gram-negative small rods with polar flagella and showing a strictly respiratory metabolism; they were characteristic of the genus Pseudomonas. A first group of 6 strains was related to the P. cepacia-P. marginata group characterized by lophotrichous flagella; they accumulated polyhydroxybutyrate, assimilated arginine and betaine, grew at 41 degrees C and showed a wide nutritional spectrum with DNA GC% of 67-68. The second group of 4 strains was related to the P. lemoignei group because of (a) its monotrichous flagella, (b) poly-beta-hydroxybutyrate accumulation, (c) failure to assimilate arginine and betaine and to grow at 41 degrees C, (d) lack of arginine dihydrolase and (e) its narrow nutritional spectrum. DNA GC% was 65. These 4 strains were also denitrifying bacteria. Six strains were related to the genus Alcaligenes because of their strictly respiratory metabolism and their peritrichous flagella; their nutritional spectrum was variable and one of them was a denitrifier. DNA GC% was 68. One strain was related to Aeromonas hydrophila of the Vibrionaceae family; it consisted of Gram-negative and oxidase-positive small rods with monotrichous polar flagella and respiratory and fermentative metabolism without gas evolution. This strain essentially assimilated sugars and its DNA GC% was 63. Another strain was a Gram- and oxidase-negative small rod with peritrichous flagella and respiratory and fermentative metabolism with gas evolution. Sugars, organic acids and amino acids were assimilated. The DNA GC% was 53. This strain was related to Enterobacter cloacae of the Enterobacteriaceae family, but it showed the additional faculty of denitrification. The last two strains studied were spirilla with amphitrichous flagella characteristic of the genus Aquaspirillum. They showed a strictly respiratory metabolism and a DNA CG% of 60-64. This study allowed us to show the N2-fixing capacity of species of Pseudomonas, Alcaligenes and Aeromonas which had been devoid of N2-fixing bacteria until this time. All strains studied were microaerophilic for N2 fixation.

Bacteria↗
PubMedDate not supplied

[Taxonomy of Bacillus circulans].

Four strains of Bacillus circulans sensu stricto (ATCC 4513 (type strain), 4515, 4516, and 4530) were subjected to 236 morphological, biochemical and physiological tests, including 162 carbon source utilization tests. B. circulans s. s. is a species of facultative anaerobes able to ferment carbohydrates. Many carbohydrates and a few aliphatic acids were used as sole carbon and energy sources, but amino acids were not. The guanine-plus-cytosine content of DNA (four strains studied) was 37.2 +/- 0.4 mol% (mean +/- standard deviation).

Bacillus↗
PubMedDate not supplied

[Numerical taxonomy of a thermophilic "Bacillus" species isolated from West African rice soils (author's transl)].

Fifty-seven strains of endospore-forming thermophilic bacteria, 37 of which were capable of denitrification, were isolated from rice soils of West Africa. They were compared with 17 strains of similar bacteria from culture collections, utilizing a total of 123 morphological, physiological and biochemical characteristics. A numerical analysis was performed using the complete linkage-clustering method and the Khi2 test. Seventy-five percent (55 strains) could be included in 12 groups at a taxonomic distance of 0.015. Wild strains of denitrifiers issued in phenons 8 to 12 and strains of phenon 4 (not denitrifying) were related to the named strains of phenons 1 and 7 (Bacillus stearothermophilus). Twenty-two wild strains, and 5 strains from culture collections, were only thermotolerating without growth at 65 degrees C. The strains of phenon 3 were related to the 3 named strains of B. coagulans. Phenons 5 and 6 were composed of strains related to B. circulans. The strains of phenon 2 denitrified and showed a swollen central endospore; they were closely related to B. brevis. The denitrifying thermophilic strains isolated from rice soils (phenons 8 to 12) were related to the first group (B. kaustophilus) of Walker and Wolf but their base compositions of DNA were significantly different from those found for the reference strains.

Africa, Western↗