Iron-chelating therapy and the treatment of thalassemia

Iron-chelating therapy with deferoxamine in patients with thalassemia major has dramatically altered the prognosis of this previously fatal disease. The successes achieved with deferoxamine, as well as the limitations of this treatment, have stimulated the design of alternative strategies of iron-chelating therapy, including orally active iron chelators. The development of the most promising of these, deferiprone, has progressed rapidly over the last 5 years; data from several trials have provided direct and supportive evidence for its short-term efficacy. At the same time, the toxicity of this agent mandates a careful evaluation of the balance between risk and benefit of deferiprone in patients with thalassemia, in most of whom long-term deferoxamine is safe and efficacious therapy.     

Bacterial survival, lymph node pathology, and serological responses of bison (Bison bison) vaccinated with Brucella abortus strain RB51 or strain 19

From August 1993 to June 1994, 3 month-old bison (Bison bison) were vaccinated with Brucella abortus strain RB51 (SRB51, n = 6), strain 19 (S19, n = 3), or with saline (n = 1) and serologic responses and persistence of vaccine strains within lymph nodes were monitored. Bison vaccinated with S19 had granulomatous lymphadenitis and greater peak numbers of B. abortus than those vaccinated with SRB51. Bison vaccinated with RB51 had similar histological lesions and B. abortus were still present in lymph nodes at 16 weeks. Although antibodies against RB51 were produced, standard tube agglutination test responses of RB51-vaccinates remained negative. The histological lesions of B. abortus infections in bison were similar to those observed in cattle, but bison did not clear SRB51 as rapidly as cattle.     

Cloning, characterization and construction of htrA and htrA-like mutants of Brucella abortus and their survival in BALB/c mice

A genomic library of Brucella abortus S2308 was screened for expression of recombinant proteins recognized by sera from mice and from cattle infected with B. abortus. A positive clone, BA1, expressing a 50 kDa peptide was recognized by both sera. Plasmid pBA1, isolated from BA1, was shown by restriction enzyme digestion to possess a 1.9 kb insert. The nucleotide sequence of the pBA1 insert revealed an open reading frame with of 1539 bases with a coding capacity of 513 amino acids and a predicted molecular weight of 50,992. The predicted amino acid sequence showed 37% identity to E. coli HtrA, a temperature inducible serine protease. A second B. abortus htrA gene, designated htrA-like, was identified on a different cloned fragment that also encoded B. abortus recA. The nucleotide sequence of the htrA-like gene revealed an open reading frame of 1422 nucleotides with a coding capacity of 474 amino acids and a predicted molecular weight of 50,155. The deduced amino acid sequence of the htrA-like gene showed 42% and 36% identity with B. abortus and E. coli HtrAs respectively. Western blotting of E. coli lysate containing the htrA-like gene was not recognized by sera from B. abortus-infected cattle or mice. B. abortus htrA but not htrA-like relieved the temperature sensitive phenotype and permitted growth of an E. coli htrA mutant at 42 degrees C. B. abortus htrA and htrA-like mutants were constructed and their survival and growth in BALB/c mice was compared to the parental strain S2308.(ABSTRACT TRUNCATED AT 250 WORDS)     

Corticostriatal mechanisms of behavior

This article presents the results of three series of experiments on cats, dogs, and lower primates, performed to investigate the structural, neurophysiological, and mediator mechanisms of the corticostriatal systems involved in the organization of behavior. Morphological studies of corticostriatal connections showed that along with the diffuse distribution of afferent terminals within the striatum, there were also elements of topical organization defined by anteroposterior and mediolateral gradients. Neurophysiological experiments on dogs and lower primates were used to study the spike activity of the prefrontal region of the cortex and the head of the caudate nucleus during training to conditioned first- and second-order reflexes and during the solution of complex problems involving delayed spatial selection. Studies demonstrated that while in dogs, most of the neurons recorded showed a transition to responses to the conditioned signal at a particular stage of carrying out a conditioned response, in monkeys all cells recorded showed specific responses at different periods of solving the task at all stages of the study. Neuropharmacological experiments on dogs showed that agents blocking glutamine receptors in the caudate nucleus had more pronounced effects at the phase of developing conditioned movement reflexes. Administration of these agents during the reflex reinforcement phase affected only the differentiation of inhibition. These results lead to the conclusion that the prefrontal area of the cortex and, to some extent, the caudate nuclei, act on incoming information specifying the current dominant need and the states of the external and internal environments, to carry out programmed actions and assess the results of these actions.     

Copolymers of alkyl methacrylates with styrene as V.I. improvers for lubricating oils

Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 1, pp. 26–28, January, 1994.     

Quantitative correlation of breast tissue parameters using magnetic resonance and X-ray mammography

BACKGROUND: Disassembly of cytoplasmic microtubules by nocodazole in cultured mammalian cells leads to the disruption of the continuous ribbonlike Golgi apparatus and dispersal of the Golgi elements from their normal juxtanuclear location, close to the microtubule-organizing center (MTOC), toward the cell periphery. Clearing of the drug induces reassembly of the microtubules from the MTOC and reorganization of the Golgi elements into a continuous ribbonlike juxtanuclear structure. In the yeast Saccharomyces cerevisiae, the Golgi apparatus does not form a continuous structure as in mammalian cells but instead constitutes independent units dispersed throughout the cytoplasm. It is the purpose of this article to investigate the role of microtubules in the structure and distribution of the Golgi elements in S. cerevisiae by studying the ultrastructure of cell organelles either in mutant cells deficient in beta-tubulin or in wild-type cells treated with the microtubule-depolymerizing drug nocodazole. METHODS: Two S. cerevisiae yeast strains were used in this study: a control wild-type strain, CUY226 (ade2-101, his3-delta 200, leu2-delta 1, lys2-801, ura3-52 Mat alpha), and a mutant strain, CUY66 (tub2-401, ade2-101, ura3-52, Mat alpha). Nocodazole was added to the wild-type cells cultivated at 30 degrees C, and cells were fixed 5 min, 20 min, and 60 min, respectively, after adding the drug to the culture. Both strains were fixed and examined 5 min, 20 min, and 60 min after shifting the cultures from the permissive temperature of 30 degrees C to the restrictive temperature of 14 degrees C. Cells were fixed in 2% glutaraldehyde, treated for 15 min in 1% sodium metaperiodate, postfixed in reduced osmium, and embedded in Epon. To visualize the three-dimensional configuration of cell organelles, stereopairs were prepared from sections stained with lead citrate and tilted at +/- 15 degrees from the 0 degree position of the goniometric stage of the electron microscope. RESULTS: In mutant cells shifted to restrictive temperature and wild-type cells treated with nocodazole, the main ultrastructural modification was a fragmentation of networks of membranous tubules, which probably correspond to the yeast Golgi apparatus. Secretion granules were still present in growing buds, and they were dispersed in the cytoplasm, which contained in addition numerous small vesicles in the 30-60-nm diameter range. CONCLUSIONS: In normal cells, small vesicles may originate from the endoplasmic reticulum and fuse together to give rise to Golgi networks (Rambourg et al. 1994. Anat. Rec., 240:32-41). If this hypothesis is correct, the observations reported might indicate that intact microtubules orient the flow of small vesicles and favour their fusion into Golgi networks.