Neurolymphomatosis of the median nerve, optic nerve, L4 spinal nerve root and cauda equina in patients with B-cell malignancies: a case series.

BACKGROUND: Neurolymphomatosis is rare. Neoplastic lymphocytes are seen to invade nerves (cranial or peripheral), nerve roots or other related structures in patients with hematological malignancy. It is a separate entity from central nervous system lymphoma. Neurolymphomatosis has most commonly been described in association with B-cell non-Hodgkin lymphoma. Neurolymphomatosis in the context of Burkitt lymphoma and the post-renal transplant setting has not been described before. CASE REPORTS: We report for the first time in the Arabian Gulf countries and nearby Arab states four cases of neurolymphomatosis (one Asian, and the other 3 are from Arabic nationals) occurring between 2012 and 2017 involving the median nerve, optic nerve, nerve root and cauda equina in patients with Burkitt lymphoma, Philadelphia chromosome-positive B-cell acute lymphoblastic leukemia and diffuse large B-cell lymphoma. CONCLUSIONS: Neurolymphomatosis is rare and can be difficult to diagnose by biopsy but reliably confirmed by a combined imaging approach. Prior treatment with high-dose dexamethasone might suppress 18F-fluorodeoxyglucose (FDG) activity and decrease the sensitivity of positron emission tomography/computed tomography (PET/CT). The prognosis is generally poor but using high-dose methotrexate as well as high-dose chemotherapy and autologous stem cell transplantation may be an effective way to treat neurolymphomatosis.

Regulatory interaction of PRL1 WD protein with Arabidopsis SNF1-like protein kinases.

Mutation of the PRL1 gene, encoding a regulatory WD protein, results in glucose hypersensitivity and derepression of glucose-regulated genes in Arabidopsis. The yeast SNF1 protein kinase, a key regulator of glucose signaling, and Arabidopsis SNF1 homologs AKIN10 and AKIN11, which can complement the Deltasnf1 mutation, were found to interact with an N-terminal domain of the PRL1 protein in the two-hybrid system and in vitro. AKIN10 and AKIN11 suppress the yeast Deltasnf4 mutation and interact with the SNF4p-activating subunit of SNF1. PRL1 and SNF4 bind independently to adjacent C-terminal domains of AKIN10 and AKIN11, and these protein interactions are negatively regulated by glucose in yeast. AKIN10 and AKIN11, purified in fusion with glutathione S-transferase, undergo autophosphorylation and phosphorylate a peptide of sucrose phosphate synthase in vitro. The sucrose phosphate synthase-peptide kinase activity of AKIN complexes detected by immunoprecipitation is stimulated by sucrose in light-grown Arabidopsis plants. In comparison with wild type, the activation level of AKIN immunocomplexes is higher in the prl1 mutant, suggesting that PRL1 is a negative regulator of Arabidopsis SNF1 homologs. This conclusion is supported by the observation that PRL1 is an inhibitor of AKIN10 and AKIN11 in vitro.

Isolation and characterization of two different cDNAs of delta1-pyrroline-5-carboxylate synthase in alfalfa, transcriptionally induced upon salt stress.

Two different cDNA clones, MsP5CS-1 and MsP5CS-2, encoding delta1 -pyrroline-5-carboxylate synthase (P5CS). the first enzyme of the proline biosynthetic pathway, were isolated from a lambdaZap-cDNA library constructed from salt stressed Medicago sativa roots. MsP5CS-1 (2.6 kb) has an open reading frame of 717 amino acids, as well as a non-spliced intron at a position corresponding to the evolutionary fusion point of the bacterial proA and proB genes. MsP5CS-2 (1.25 kb) is a partial clone. The clones share 65% identity in nucleotide sequences, 74% homology in deduced amino acid sequences, and both show a high similarity to Vigna aconitifolia and Arabidopsis thaliana P5CS cDNA clones. Southern blot analysis confirmed the presence of two different P5CS genes. The effect of salinity on the transcription of MsP5CS-1 and MsP5CS-2 in roots was studied, using northern blot analysis and a RT-PCR approach. A rapid increase in the steady-state transcript level of both genes in roots was observed by RT-PCR upon exposure of hydroponically grown 6-day old seedlings to 90 mM NaCl, suggesting that both are salt-inducible genes, yet a higher response was observed for MsP5CS-2.

Gene identification with sequenced T-DNA tags generated by transformation of Arabidopsis cell suspension.

A protocol for establishment and high-frequency Agrobacterium-mediated transformation of morphogenic Arabidopsis cell suspensions was developed to facilitate saturation mutagenesis and identification of plant genes by sequenced T-DNA tags. Thirty-two self-circularized T-DNA tagged chromosomal loci were isolated from 21 transgenic plants by plasmid rescue and long-range inverse polymerase chain reaction (LR-iPCR). By bidirectional sequencing of the ends of T-DNA-linked plant DNA segments, nine T-DNA inserts were thus localized in genes coding for the Arabidopsis ASK1 kinase, cyclin 3b, J-domain protein, farnesyl diphosphate synthase, ORF02, an unknown EST, and homologues of a copper amine oxidase, a peripheral Golgi protein and a maize pollen-specific transcript. In addition, 16 genes were identified in the vicinity of sequenced T-DNA tags illustrating the efficiency of genome analysis by insertional mutagenesis.

Differential expression of two P5CS genes controlling proline accumulation during salt-stress requires ABA and is regulated by ABA1, ABI1 and AXR2 in Arabidopsis.

Proline is a common compatible osmolyte in higher plants. Proline accumulation in response to water stress and salinity is preceded by a rapid increase of the mRNA level of delta 1-pyrroline-5-carboxylate synthase (P5CS) controlling the rate-limiting step of glutamate-derived proline biosynthesis. P5CS is encoded by two differentially regulated genes in Arabidopsis. Gene AtP5CS1 mapped to chromosome 2-78.5 is expressed in most plant organs, but silent in dividing cells. Gene AtP5CS2 located close to marker m457 on chromosome 3-101.3 contributes 20-40% of total P5CS mRNA in plant tissues, but is solely responsible for the synthesis of abundant P5CS mRNA in rapidly dividing cell cultures. Accumulation of AtP5CS transcripts is regulated in a tissue specific manner and inducible by drought, salinity, ABA, and to a lesser extent by auxin. Induction of AtP5CS1 mRNA accumulation in salt-treated seedlings involves an immediate early transcriptional response regulated by ABA signalling that is not inhibited by cycloheximide, but abolished by the deficiency of ABA biosynthesis in the aba1 Arabidopsis mutant. However, inhibition of protein synthesis by cycloheximide prevents the induction of AtP5CS2 mRNA accumulation, and blocks further increase of AtP5CS1 mRNA levels during the second, slow phase of salt-induction. Mutations abi1 and axr2, affecting ABA-perception in Arabidopsis, reduce the accumulation of both AtP5CS mRNAs during salt-stress, whereas ABA-signalling functions defined by the abi2 and abi3 mutations have no effect on salt-induction of the AtP5CS genes.

A simple method for isolation, liquid culture, transformation and regeneration of Arabidopsis thaliana protoplasts.

An efficient technique was developed for the isolation, culture, transformation and regeneration of protoplasts derived from auxin conditioned Arabidopsis root cultures. On an average 30% of root protoplasts underwent cell division in liquid culture and formed somatic embryolike structures which regenerated to plants without embedding in Ca(2+)-alginate. The protoplast protocol was applicable to different landraces of Arabidopsis thaliana (L.) Heynh., such as RLD, Columbia or C24. PEG-mediated DNA uptake into protoplasts using different uidA reporter gene constructs yielded transient gene expression in over 25% of treated cells indicating that root-derived protoplasts are suitable recipients for transformation.

Site-specific mutagenesis of the nodule-infected cell expression (NICE) element and the AT-rich element ATRE-BS2* of the Sesbania rostrata leghemoglobin glb3 promoter.

Sesbania rostrata leghemoglobin glb3 (Srglb3) promoter sequences responsible for expression in infected cells of transgenic Lotus corniculatus nodules were delimited to a 78-bp Dral-Hinfl fragment. This region, which is located between coordinates -194 to -116 relative to the start codon of the Srglb3 gene, was named the nodule-infected cell expression (NICE) element. Insertion of the NICE element into the truncated nopaline synthase promoter was found to confer a nodule-specific expression pattern on this normally root-enhanced promoter. Within the NICE element, three distinct motifs ([A]AAAGAT, TTGTCTCTT, and CACCC[T]) were identified; they are highly conserved in the promoter regions of a variety of plant (leg)hemoglobin genes. The NICE element and the adjacent AT-rich element (ATRE-BS2*) were subjected to site-directed mutagenesis. The expression patterns of nine selected Srglb3 promoter fragments carrying mutations in ATRE-BS2* and 19 with mutations in the NICE element were examined. Mutations in ATRE-BS2* had varying effects on Srglb3 promoter activity, ranging from a two- to threefold reduction to a slight stimulation of activity. Mutations in the highly conserved (A)AAAGAT motif of the NICE element reduced Srglb3 promoter activity two- to fourfold, whereas mutations in the TCTT portion of the TTGTCTCTT motif virtually abolished promoter activity, demonstrating the essential nature of these motifs for Srglb3 gene expression. An A-to-T substitution in the CACCC(T) motif of the NICE element also abolished Srglb3 promoter activity, while a C-to-T mutation at position 4 resulted in a threefold reduction of promoter strength. The latter phenotypes resemble the effect of similar mutations in the conserved CACCC motif located in the promoter region of mammalian beta-globin genes. The possible analogies between these two systems will be discussed.

Functional analysis of the Sesbania rostrata leghemoglobin glb3 gene 5'-upstream region in transgenic Lotus corniculatus and Nicotiana tabacum plants.

Expression of the Sesbania rostrata leghemoglobin glb3 gene was analyzed in transgenic Lotus corniculatus and tobacco plants harboring chimeric glb3-uidA (gus) gene fusions to identify cis-acting elements involved in nodule-specific gene expression and general transcriptional control. A 1.9-kilobase fragment of the glb3 5'-upstream region was found to direct a high level of nodule-specific beta-glucuronidase (GUS) activity in L. corniculatus, restricted to the Rhizobium-infected cells of the nodules. The same fragment directed a low level of GUS activity in tobacco, restricted primarily to the roots and to phloem cells of the stem and petiole vascular system. A deletion analysis revealed that the region between coordinates -429 and -48 relative to the ATG was sufficient for nodule-specific expression. Replacement of the -161 to -48 region, containing the glb3 CAAT and TATA boxes, with the heterologous truncated promoters delta-p35S and delta-pnos resulted in a loss of nodule specificity and reduction of GUS activity in L. corniculatus but a significant increase in tobacco, primarily in the roots. The same fragment could not direct nodule-specific expression when fused to a heterologous enhancer in cis. This region contains DNA sequences required, but not sufficient, for nodule-specific expression in L. corniculatus that function poorly or may be involved in promoter silencing in tobacco. By fusing further upstream fragments to the delta-p35S and delta-pnos promoters, two positive regulatory regions were delimited between coordinates -1601 and -670, as well as -429 and -162. The former region appears to function as a general enhancer because it significantly increased promoter activity in both orientations in L. corniculatus and tobacco. The latter region could enhance gene expression in both orientations in tobacco, but only in the correct orientation in L. corniculatus. These results show that efficient expression of the S. rostrata glb3 gene in nodules is mediated by an ATG-proximal, tissue-specific element, as well as further 5'-upstream positive elements; that the S. rostrata glb3 promoter is induced in a nodule-specific fashion in the heterologous legume L. corniculatus, suggesting a high degree of conservation of the relevant regulatory signals; and that the S. rostrata lb promoter is not silent in the nonlegume tobacco, but is expressed primarily in the roots.

Chimeric genes and transgenic plants are used to study the regulation of genes involved in symbiotic plant-microbe interactions (nodulin genes).

Nodulin genes are plant genes specifically activated during the formation of nitrogen-fixing nodules on leguminous plants. These genes are interesting to study since they are not only induced in a specific developmental fashion by signals coming directly or indirectly from the rhizobial symbiont, but are also expressed in a tissue-specific manner. By examining the expression of chimeric nodulin-reporter genes in transgenic legume plants it has been shown that nodule specific expression is mediated by DNA sequences present in the 5 upstream region of several nodulin genes. Here we summarize the available data on these cis-acting elements and the trans-acting factors interacting with them. We also review experiments designed to identify rhizobial "signals" which may play a role in nodule specific gene expression.

Regulation of plant genes specifically induced in nitrogen-fixing nodules: role of cis-acting elements and trans-acting factors in leghemoglobin gene expression.

Transgenic alfalfa plants harboring a gene fusion between the soybean leghemoglobin (lbc3) promoter region and the chloramphenicol acetyl transferase (cat) gene were used to determine the influence of rhizobial mutants on lb gene expression in nodules. The promoter region of the Sesbania rostrata glb3 (Srglb3) leghemoglobin gene was examined for the presence of conserved motifs homologous to binding site 1 and 2 of the soybean lbc3 promoter region, found to interact with a trans-acting factor present in soybean nodule nuclear extracts (Jensen EO, Marcker KA, Schell J, de Bruijn FJ, EMBO J 7:1265-1271, 1988). Subfragments of the S. rostrata glb3 (Srglb3) promoter region were examined for binding to trans-acting factors from nodule nuclear extracts. In addition to the binding sites previously identified (Metz BA, Welters P, Hoffmann HJ, Jensen EO, Schell J, de Bruijn FJ, Mol Gen Genet 214: 181-191), several other sites were found to interact with trans-acting factors. In most cases the same trans-acting factor(s) were shown to be involved. One fragment (202) was found to bind specifically to a different factor (protein) which was extremely heat-resistant (100 degrees C). The appearance of this factor was shown to be developmentally regulated since the expected protein-DNA complexes were first observed around 12 days after infection, concomitant with the production of leghemoglobin proteins. Fragments of the Srglb3 5' upstream region were fused to the beta-glucuronidase reporter gene with its own CAAT and TATA box region or those of the cauliflower mosaic virus 35S and nopaline synthase (nos) promoters.(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro somatic embryogenesis and plant regeneration of cassava.

An efficient and reproducible plant regeneration system, initiated in somatic tissues, has been devised for cassava (Manihot esculenta Crantz). Somatic embryogenesis has been induced from shoot tips and immature leaves of in vitro shoot cultures of 15 cassava genotypes. Somatic embryos developed directly on the explants when cultured on a medium containing 4-16 mg/l 2,4-D. Differences were observed with respect to the embryogenic capacity of the explants of different varieties. Secondary embryogenesis has been induced by subculture on solid or liquid induction medium. Long term cultures were established and maintained for up to 18 months by repeated subculture of the proliferating somatic embryos. Plantlets developed from primary and secondary embryos in the presence of 0.1 mg/l BAP, 1mg/l GA3, and 0.01 mg/l 2,4-D. Regenerated plants were transferred to the field, and were grown to maturity.

Regeneration of isolated mesophyll and cell suspension protoplasts to plants in Stylosanthes guianensis. A tropical forage legume.

Protoplasts were isolated from leaf mesophyll and cell suspensions of two accessions of Stylosanthes guianensis (Aubl.), a tropical forage legume. When cultured in VKM liquid culture medium, both types of protoplasts divided at a rate of 4-8%, and subsequently formed cell colonies. Protoplast-derived calluses produced numerous shoots when transferred to regeneration medium. Regenerated shoots could be easily rooted, and plantlets were transferred to soil. The effects of several factors on the efficiency of this protoplast system have been investigated.

Callus formation from protoplasts of a sugarbeet cell suspension culture.

Protoplasts of sugarbeet (Beta vulgaris L.) were isolated from cell suspension cultures and cultured in modified PGo medium. Conditions required for the efficient division of the protoplasts were investigated.The optimal combination of phytohormones was found to be 1 mg/l NAA, 0.2 mg/l 2,4-D, 0.5 mg/l zeatin. Protoplast division was also considerably stimulated by the addition of 250 mg/l casein hydrolysate, 200 mg/l yeast extract, and 20% v/v conditioned culture medium to the protoplast culture medium. The highest division rate (up to 35% of the protoplasts) was achieved at a density of 4×10(4)- 1×10(5) protoplasts/ml. From the colonies callus and suspension cultures were readily obtained.

Low serotonin uptake by platelets in leprosy and a new approach to prevent it.

The plasma of leprosy patients contains high levels of mucoproteins which are deficient in sialic acid. However, due to the increased mucoprotein level, the total sialic acid content of leprous plasma, calculated on protein, is increased when compared with normal human plasma. The low serotonin uptake observed with isolated platelets is probably due to their low sialic acid content. The inability of normal human plasma to correct the diminished serotonin uptake by isolated leprous platelets is in favor of a definite structural change in leprous platelets, related to their low sialic acid content. In patients with active disease and in those with lepra reactions, leprous plasma itself can correct the diminished uptake of serotonin by the isolated platelets. In patients with subsided lepra reactions, the leprous plasma is much less effective. In severe cases, where serotonin uptake is decreased even in platelet rich plasma, desoxyfructo-serotonin increased the uptake of serotonin.

Uptake of isolated plant chromosomes by plant protoplasts.

For mass isolation of plant metaphase chromosomes, cultured cells of wheat (Triticum monococcum) and parsley (Petroselinum hortense) were synchronized by hydroxyurea and colchicine treatment. This synchronization procedure resulted in high mitotic synchrony, especially in suspension cultures of parsley in which 80% of the cells were found to be at the metaphase stage. Mitotic protoplasts isolated from these synchronized cell cultures served as a source for isolation of chromosomes. The described isolation and purification method yielded relatively pure chromosome suspension. The uptake of the isolated plant chromosomes into recipient wheat, parsley, and maize protoplasts was induced by polyethylene-glycol treatment. Cytological studies provided evidences for uptake of plant chromosomes into plant protoplasts.