Nuclear IMPDH Filaments in Human Gliomas

The analysis of nuclear morphology plays an important role in glioma diagnosis and grading. We previously described intranuclear rods (rods) labeled with the SDL.3D10 monoclonal antibody against class III beta-tubulin (TUBB3) in human ependymomas. In a cohort of adult diffuse gliomas, we identified nuclear rods in 71.1% of IDH mutant lower-grade gliomas and 13.7% of IDH wild-type glioblastomas (GBMs). The presence of nuclear rods was associated with significantly longer postoperative survival in younger (≤65) GBM patients. Consistent with this, nuclear rods were mutually exclusive with Ki67 staining and their prevalence in cell nuclei inversely correlated with the Ki67 proliferation index. In addition, rod-containing nuclei showed a relative depletion of lamin B1, suggesting a possible association with senescence. To gain insight into their functional significance, we addressed their antigenic properties. Using a TUBB3-null mouse model, we demonstrate that the SDL.3D10 antibody does not bind TUBB3 in rods but recognizes an unknown antigen. In the present study, we show that rods show immunoreactivity for the nucleotide synthesizing enzymes inosine monophosphate dehydrogenase (IMPDH) and cytidine triphosphate synthetase. By analogy with the IMPDH filaments that have been described previously, we postulate that rods regulate the activity of nucleotide-synthesizing enzymes in the nucleus by sequestration, with important implications for glioma behavior.

A highly flexible system for microstimulation of the visual cortex: design and implementation

This paper presents the design of a system intended to be used as a prosthesis allowing profoundly visually impaired patients to recover partial vision by means of microstimulation in the primary visual cortex area. The main component of the system is a bio-electronic device to be implanted inside the skull of the user, composed of a plurality of stimulation modules, whose actions are controlled via an interface module. Power and data are transmitted to the implant wirelessly through a bidirectional inductive link, allowing diagnosis of the stimulating device and its environment after implantation, as well as power delivery optimization. A high level of flexibility is supported in terms of stimulation parameters, but a configurable communication protocol allows the device to be used with maximum efficiency. The core of an external controller implemented in a system on a programmable chip is also presented, performing data conversion and timing management such that phosphene intensity can be modulated by any parameter defining stimulation, either at the pulse level or in the time domain. Measured performances achieved with a prototype using two types of custom ASICs implemented in a 0.18-mum CMOS process and commercial components fulfill the requirements for a complete visual prosthesis for humans. When on/off activation is used with predefined parameters, stimuli measured on an electronic test bench could attain a rate in excess of 500 k pulses/s.

Hedgehog interacting protein in the mature brain: membrane-associated and soluble forms

Hedgehog interacting protein (Hip) is considered as a membrane protein implicated in sequestering the hedgehog (hh) morphogens during embryonic development. Here, we demonstrate that Hip transcription also occurs in cells scattered in discrete brain areas of adult rodents and we identify the presence of membrane-associated and soluble forms of Hip in the mature brain. Moreover, we show that soluble forms of Hip, present in the conditioned medium of HEK293 cells overexpressing Hip, inhibit Sonic hedgehog (Shh)-induced differentiation of C3H10T1/2 cells, a well-characterised response associated with Shh signalling. After transfection in HEK293 cells, Hip partitions with the raft component ganglioside GM1 during density gradient centrifugation. Analysis of tagged Hip constructs reveals that the putative transmembrane domain of Hip is not cleaved suggesting that other mechanisms are implicated in the release of its soluble forms. Taken together, these data are consistent with the involvement of both membrane-associated and soluble Hip in the regulation of Shh signalling in adult neural tissues.

Towards optimization of growth via nutrient supply phasing: nitrogen supply phasing increases broccoli (Brassica oleracea var. italica) growth and yield

A greenhouse experiment on broccoli (Brassica oleracea var. italica, cvs Windsor and Arcadia) was carried out in order to demonstrate that supplying nitrogen (N) to meet the nitrogen demands of plant growth stages, through N phasing, improves plant growth and yield, as compared to fertilizing at the conventional, optimal, constant N rate. Two broccoli cultivars and two rates of starter nitrogen fertilizer (optimum, 250 mg l(-1) and sub-optimum, 150 mg l(-1)), were combined with three timings of fertigation change. Shifting N rate, at 60% and 75% of the market plant growth cycle significantly increased shoot dry weight and head fresh weight, compared to the constant-N rates treatments (controls). The highest yield and shoot dry weight were obtained when the N-rate was switched from the optimum level (250 mg l(-1)) to the sub-optimum level (150 mg l(-1)) at inflorescence initiation. The nitrogen-to-growth-stage-fitness effect was determined and partitioned into rate effect and phasing effect. The phasing effect was greatest, on both shoot dry weight and head fresh weight, at inflorescence initiation, and subsequently decreased until harvest time. None of the interactions was significant. The results demonstrated the superiority of nitrogen supply phasing over the conventional fixed-rate-supply method.

Synergy of activin and ciliary neurotrophic factor signaling pathways in the induction of vasoactive intestinal peptide gene expression

Activin, a member of the transforming growth factor-beta superfamily, can regulate neuropeptide gene expression in the nervous system and in neuroblastoma cells. Among the neuropeptide genes whose expression can be regulated by activin is the gene encoding the neuropeptide vasoactive intestinal peptide (VIP). To investigate the molecular mechanisms by which activin regulates neuronal gene expression, we have examined activin's regulation of VIP gene expression in NBFL neuroblastoma cells. We report here that NBFL cells respond to activin by increasing expression of VIP mRNA. Activin regulates VIP gene transcription in NBFL cells through a 180-bp element in the VIP promoter that was previously characterized to be necessary and sufficient to mediate the induction of VIP by the neuropoietic cytokines and termed the cytokine response element (CyRE). We find that the VIP CyRE is necessary and sufficient to mediate the transcriptional response to activin. In addition, ciliary neurotrophic factor (CNTF), a neuropoietic cytokine, synergizes with activin to increase VIP mRNA expression and transcription through the VIP CyRE. Mutations in either the Stat (signal transducer and activator of transcription) or AP-1 sites within the CyRE that reduce the response to CNTF, also reduce the response to activin. However, mutating both the Stat and AP-1 sites within the wild-type CyRE, while reducing the separate responses to either activin or CNTF, eliminates the synergy between them. These data suggest that activin and CNTF, two factors that appear to signal though distinct pathways, activate VIP gene transcription through a common transcriptional element, the VIP CyRE.

Influence of lipid diets on the number of metastases and ganglioside content of H59 variant tumors

We investigated the influence of the fatty acid composition of the diet on the number of hepatic metastases and the ganglioside profile of the primary tumor and metastases. C57BL/6 female mice were fed different diets containing either no fats (TEK) or 8% of fish oil (POL), linseed oil (LIN), safflower oil (SAF) or beef tallow (BT) and were injected subcutaneously in the dorsum with H59 cells, a variant of the Lewis lung carcinoma (3LLc) that metastasizes preferentially to the liver. The omega3 polyunsaturated fatty acid (PUFA)-rich diets (LIN and POL) elicited more metastases than the omega6 PUFA-rich (SAF), fat-free (TEK), or saturated fats (BT) diets. However, dietary fat did not influence the ganglioside composition of either the primary tumors or the metastases, at least in the glucidic part. However, comparison of diets with low (TEK, SAF, and BT) and high (LIN and POL) number of metastases showed that the levels of G3 (which could be a second band of GM2) were greater in metastases of the latter group. This study showed that the H59 hepatic metastases contained more GM2 than the s.c. tumors, irrespective of diet or the number of metastases produced. The small differences in the ganglioside profiles observed in this study could have resulted from the limitations of the HPTLC method. A detailed analysis of the lipid chains, as well as glycolipids other than gangliosides, could give more information on changes resulting from different lipid diets.

A replication-competent promoter-trap retrovirus

A promoter-trap retrovirus has been constructed in which a promoterless polyomavirus middle T antigen gene was inserted in the U3 region of the long terminal repeat of a replication-competent Moloney murine leukemia virus. The resulting virus, designated PyT, was used to infect mouse mammary glands in situ. As expected, mammary tumors appeared in some infected animals. These tumors were found to contain PyT proviruses of the predicted structure. From one such tumor, the PyT provirus and surrounding sequences from the integration site were cloned. The provirus was found to have integrated adjacent to the promoter of a novel mouse gene (TRAP1) that was expressed at low levels in various mouse tissues. These data show that the PyT retrovirus provides a sensitive means of detecting active promoters in vivo.

Gangliosides in human uveal melanoma metastatic process

The inability of current therapy to prevent metastases arising from uveal melanoma often results in patient mortality. With the goal of developing a treatment for metastasis, gangliosides were studied as potential tumor-associated antigens. Our report describes the production of a metastatic liver variant (MH) from a human uveal melanoma cell line (SP6.5). Cells were injected into nude mouse spleens and liver metastases collected 2 months later. After 21 days of in vitro subculture, the cells were re-injected into normal nude mice spleen; 10 cycles (MH10) were performed. Gangliosides were extracted, purified, chromatographed on HPTLC plates and sprayed with a resorcinol-HCl reagent, the sialic acid spots being quantified by densitometry. Gangliosides were analyzed in each metastatic liver variant and compared with the SP6.5 s.c. tumor. The results showed a significant increase in GM3 and a significant decrease in GD3 and GD2 in the last metastatic variants obtained (MH5, MH8, MH9 and MH1O) compared with the primary s.c. tumor, SP6.5. Such evolution in the ganglioside pattern was maintained throughout the progression of the different liver variants. Our results indicate that precursor ganglioside GM3 and gangliosides GD3 and GD2 could be associated with neoplastic evolution of malignancy of human uveal melanoma in nude mice.

Persistent vegetative state: which sensory-motor variables should the physiotherapist measure?

This study used a modified Delphi technique to establish a list of core items which should be included in the measurement, by the physical therapist, of sensory-motor capacities of persons in a persistent vegetative state. Twenty-eight physical therapists with a mean of 5.9 years of experience working with this clientele participated in the study and identified 105 items as being important in the evaluation of the PVS patient (Round I). The study planning committee reduced these to 20 categories and asked the therapists to rate each category of items (a 5-point scale) as to it's importance (Round II). Physiotherapists identified 14 variables as being 'extremely' or 'very important' to include in such an evaluation. These included: tonus, voluntary movement on request, postural reactions, passive range of motion, tolerance to verticalization and postural status. These results are being used to develop a quantitative assessment instrument to be used by the physical therapist working with the PVS patient.

Replication of a Moloney murine leukemia virus mutant lacking the ELP binding site

A mutant Moloney murine leukemia virus was created in which the binding site for the embryonal long terminal repeat binding protein had been replaced with a synthetic linker sequence. The virus was found to replicate normally in murine 3T3 fibroblasts, and the mutation was stably transmitted throughout repeated passages. The binding site is therefore dispensable with respect to viral replication. Titers of the mutant virus were comparable to those of wild-type preparations, even when supernatants were prepared from undifferentiated P19 embryonal carcinoma cells. Elimination of the repressor binding site therefore had little effect on viral replication in embryonal carcinoma cells. Elimination of the repressor binding site therefore had little effect on viral replication in embryonal cells, an unexpected result in light of the reported activity of the binding protein as a transcriptional repressor.

Plasmid DNA is superior to viral vectors for direct gene transfer into adult mouse skeletal muscle

Direct gene transfer into skeletal muscle offers several therapeutic possibilities. We assessed direct intramuscular injection of recombinant plasmids, adenovirus, or retrovirus in normal or regenerating muscles of mice. The incorporation and expression of reporter genes introduced by any of these three vectors is greater in regenerating than in mature muscle. In regenerating muscle, pure DNA and adenovirus result in equivalent numbers of fibers expressing reporter gene (> 10%), but adenovirus also induces considerable cellular infiltration. In mature muscle, recombinant DNA is better than adenovirus. Retrovirus failed to infect mature muscle fibers and was less effective than plasmid DNA or adenovirus in regenerating muscle. The surprisingly high relative efficiency of pure plasmid DNA suggests that this method will provide a simple, safe and viable alternative for gene therapy involving muscle tissue.

Gangliosides and organ-specific metastatic colonization

To investigate whether metastatic specificity is associated with a variation in the ganglioside profile of the parent cell lines, we have analyzed and compared the ganglioside content of subcutaneous (s.c.) tumors to that of the corresponding metastases. C57BL/6 mice were injected with either the Lewis lung carcinoma (3LLc) or its cloned variants, M27, exclusively metastatic to the lung, and H59, metastasizing preferentially to the liver. Gangliosides were extracted, purified and separated on HPTLC. H59 liver metastases contained significantly more GM2 (27.8%) than the H59 s.c. tumor (7.6%). The ganglioside profiles of 3LLc or M27 s.c. tumors were no different from those of their corresponding metastases. GM2 predominated in the liver (90.8%) while GM3 (48.8%) and GM2 (33.8%) were prevalent in the lung. Unidentified gangliosides designated G1, G2, G4 and G5 were present in tumor cells but absent from normal lung and liver. This study indicates that the ganglioside compositions of the 3LLc cell line and of its M27 variant were not modified under the influence of different sites of growth. Furthermore, the ganglioside profiles of the metastases were distinct from those of their respective target organs. The results of these studies suggest a possible relationship between GM2 and the establishment of H59 metastases in the liver.

Activation of simian virus 40 transcription in vitro by T antigen

Simian virus 40 is repressed when the viral early gene product large tumor antigen (TAg) binds to specific sites within the viral origin and DNA replication ensues. Late transcription is activated by TAg, even in the absence of viral DNA replication. We show here that TAg produced in human 293 cells can selectively activate Simian virus 40 transcription in a cell-free system. In the absence of DNA binding by TAg, early and late transcription are both activated, as they are in vivo, suggesting that the effect might be mediated by a cellular component(s) utilized by both the early and late promoters. When TAg binds to the viral origin of replication, early transcription is repressed but the late promoter activation is unaffected. Various preparations of TAg differed in their activities, with some able both to bind DNA and to activate transcription and others able to do only one or the other. Since these variations might be explained by variable amounts of associated factors that copurified with TAg, we asked whether a bacterially derived protein could regulate transcription. An NH2-terminal 272-amino-acid fragment of TAg, produced in Escherichia coli as a glutathione S-transferase fusion protein, retains the ability to activate transcription in vitro, similar to that of the full-length protein. Structural features of this region that might be important are discussed.

Development of cholinergic traits in the quail ciliary ganglion: expression of choline acetyltransferase-like immunoreactivity

The avian ciliary ganglion is a parasympathetic ganglion derived from the neural crest whose neurons provide cholinergic innervation to the eye. Here, we describe the time course of appearance and the morphology of cholinergic cells in the ciliary ganglion, as assessed by antibodies against choline acetyltransferase. Choline acetyltransferase immunoreactivity was first observed in 5.5-day-old quail embryos, 1 day after condensation of the ciliary ganglion. Both the intensity of choline acetyltransferase immunoreactivity and size of the choline acetyltransferase-immunoreactive cells increased with ganglionic age. By 12 days, a second population of choline acetyltransferase-immunoreactive cells, possibly corresponding to choroid neurons, was observed whose cells were smaller and less intensely stained than earlier differentiating choline acetyltransferase-immunoreactive cells. The percentage of choline acetyltransferase-immunoreactive cells was initially high, constituting approximately 50% of the total cell population. As a function of time, the proportion of cholinergic cells decreased, probably due to proliferation of non-neuronal cells and naturally-occurring cell death. Our results confirm the existence of two morphologically distinct populations of cholinergic neurons in the avian ciliary ganglion and demonstrate that these neuronal subpopulations express choline acetyltransferase immunoreactivity at different times in development. Because choroid neurons innervate their targets later than ciliary neurons, this finding is consistent with the hypothesis that target interactions regulate expression of choline acetyltransferase.

Laser microsurgery in cell and developmental biology

New applications of laser microbeam irradiation to cell and developmental biology include a new instrument with a tunable wavelength (217- to 800-nanometer) laser microbeam and a wide range of energies and exposure durations (down to 25 X 10(-12) second). Laser microbeams can be used for microirradiation of selected nucleolar genetic regions and for laser microdissection of mitotic and cytoplasmic organelles. They are also used to disrupt the developing neurosensory appendages of the cricket and the imaginal discs of Drosophila.

Measurement of outcomes of care for stroke patients

A coordinated system of care for stroke patients is established in the community of Fall River, Massachusetts, involving the Stroke Unit of Union Hospital, the Rehabilitation Unit of Earle E. Hussey Hospital, and the Fall River District Nurse Association. Long-Range Evaluation Summary (LRES) data collection forms developed at the Tufts University Medical Rehabilitation Research and Training Center (RT-7) are being used to reflect the functional status of the patient at any given point in time. Of 164 patients the Stroke Unit returned 49% home and the Rehabilitation Unit returned another 9% home. This systematic approach to functional assessment relates the disease-state and disability to outcomes of care. By taking into account the several-fold nature of outcome determination it is possible to analyze program effectiveness because such uniform descriptions, over time, permit us better to relate the population under care, its key characteristics for these purposes, and the comprehensiveness of problem identification and planning all at the same time.