Tuber luomae, a new spiny-spored truffle species from the Pacific Northwest, USA.

Tuber luomae, a new truffle species known only from the Pacific Northwest, USA, is distinguished by spiny, non-reticulate spores and a two-layered peridium - the outermost layer (pellis) consists of inflated, globose to subpolygonal cells and the inner (subpellis) of narrow hyphae. ITS sequence analyses show that it has phylogenetic affinity to other Tuber species in the Rufum clade. The only other members of the Rufum clade with a strongly developed peridiopellis of large, inflated cells are the southern European T. malacodermum and T. pustulatum and the northern Mexican T. theleascum. We find it interesting that this peridial structure that is uncommon in the Rufum clade has been found in geographically disjunct species.

Effect of a novel nonviral gene delivery of BMP-2 on bone healing.

BACKGROUND: Gene therapeutic drug delivery approaches have been introduced to improve the efficiency of growth factors at the site of interest. This study investigated the efficacy and safety of a new nonviral copolymer-protected gene vector (COPROG) for the stimulation of bone healing. METHODS: In vitro, rat osteoblasts were transfected with COPROG + luciferase plasmid or COPROG + hBMP-2 plasmid. In vivo, rat tibial fractures were intramedullary stabilized with uncoated versus COPROG+hBMP-2-plasmid-coated titanium K-wires. The tibiae were prepared for biomechanical and histological analyses at days 28 and 42 and for transfection/safety study at days 2, 4, 7, 28, and 42. RESULTS: In vitro results showed luciferase expression until day 21, and hBMP-2-protein was measured from day 2 - day 10. In vivo, the local application of hBMP-2-plasmid showed a significantly higher maximum load after 42 days compared to that in the control. The histomorphometric analysis revealed a significantly less mineralized periosteal callus area in the BMP-2 group compared to the control at day 28. The rt-PCR showed no systemic biodistribution of luciferase RNA. CONCLUSION: A positive effect on fracture healing by nonviral BMP-2 plasmid application from COPROG-coated implants could be shown in this study; however, the effect of the vector may be improved with higher plasmid concentrations. Transfection showed no biodistribution to distant organs and was considered to be safe.

Rediscovery of the vesicles that characterized Rhizopogon vesiculosus.

Molecular distinction between Rhizopogon vinicolor and R. vesiculosus has been made recently, but the diagnostic "yellow-brown (fresh) inflated cells" of R. vesiculosus, originally described by AH Smith, were not observed. These distinctive hyphal cells (vesicles) have not been reported since the type description. In that description they were said to collapse upon drying and described as being difficult to find. Here we report the rediscovery of these vesicles and describe their specific location on sporocarps of R. vesiculosus. We also report an original discovery that coiled, dark-walled hyphae on the sporocarps and in the mycorrhizae of R. vinicolor are of taxonomic value. The coiled hyphae, combined with the presence or absence of the elusive vesicles, allow R. vesiculosus and R. vinicolor to be morphologically distinguished with increased accuracy.

EphA4 constitutes a population-specific guidance cue for motor neurons.

Motor neurons in the ventral neural tube project axons specifically to their target muscles in the periphery. Although many of the transcription factors that specify motor neuron cell fates have been characterized, less is understood about the mechanisms that guide motor axons to their correct targets. We show that ectopic expression of EphA4 receptor tyrosine kinase alters the trajectories of a specific population of motor axons in the avian hindlimb. Most motor neurons in the medial portion of the lateral motor column (LMC) extend their axons aberrantly in the dorsal nerve trunk at the level of the crural plexus, in the presence of ectopic EphA4. This misrouting of motor axons is not accompanied by alterations in motor neuron identity, settling patterns in the neural tube, or the fasciculation of spinal nerves. However, ectopic EphA4 axons do make errors in pathway selection during sorting in the plexus at the base of the hindlimb. These results suggest that EphA4 in motor neurons acts as a population-specific guidance cue to control the dorsal trajectory of their axons in the hindlimb.

EphA4/ephrin-A5 interactions in muscle precursor cell migration in the avian forelimb.

Limb muscles derive from muscle precursor cells that lie initially in the lateral portion of the somitic dermomyotome and subsequently migrate to their target limb regions, where muscle-specific gene transcription is initiated. Although several molecules that control the generation and delamination of muscle precursor cells have been identified, little is known about the mechanisms that guide muscle precursor cell migration in the limb. We have examined the distribution of members of the Eph family during muscle precursor cell development. The EphA4 receptor tyrosine kinase and its ligand, ephrin-A5, are expressed by muscle precursor cells and forelimb mesoderm in unique spatiotemporal patterns during the period when muscle precursors delaminate from the dermomyotome and migrate into the limb. To test the function of EphA4/ephrin-A5 interactions in muscle precursor migration, we used targeted in ovo electroporation to express ephrin-A5 ectopically specifically in the presumptive limb mesoderm. In the presence of ectopic ephrin-A5, Pax7-positive muscle precursor cells are significantly reduced in number in the proximal limb, compared with controls, and congregate abnormally near the lateral dermomyotome. In stripe assays, isolated muscle precursor cells avoid substrate-bound ephrin-A5 and this avoidance is abolished by addition of soluble ephrin-A5. These data suggest that ephrin-A5 normally restricts migrating, EphA4-positive muscle precursor cells to their appropriate territories in the forelimb, disallowing entry into abnormal embryonic regions.

Sparking new frontiers: using in vivo electroporation for genetic manipulations.

In vivo electroporation is a fascinating new approach by which gene expression, regulation, and function can be studied in developmental systems. This technique offers new opportunities for manipulations in animal models that lack genetic approaches, including avians. Furthermore, this approach is applicable to other embryo populations including mice, ascidians, zebrafish, Xenopus, and Drosophila. In this review, we discuss technical aspects of in vivo electroporation, review recent studies where this approach has been utilized successfully, and identify future directions.

Merger failure: a five-year journey examined.

In 1994, Catholic Medical Center and Elliot Hospital in Manchester, New Hampshire, merged to form Optima Health, a full-ownership, not-for-profit IDS. Initially, Optima Health was an economic success. A number of strategic miscalculations, however, led to the IDS's demise. First, Optima Health's leaders failed to fully consider the divergent cultures of the two hospitals, particularly with respect to their religious differences. Second, Optima Health's leaders did not anticipate the public's response to the organization's consolidation plan. And third, the consolidation was found to have changed the charitable missions of the two tax-exempt hospitals in violation of Federal laws regarding charitable trusts. The issues combined to undermine the commitment of the organization's leaders to the consolidation strategy, and Optima Health was dissolved.

Expression of EphA4, ephrin-A2 and ephrin-A5 during axon outgrowth to the hindlimb indicates potential roles in pathfinding.

During neural development, spinal motor axons extend in a precise manner from the ventral portion of the developing spinal cord to innervate muscle targets in the limb. Although classical studies in avians have characterized the cellular interactions that influence motor axon pathfinding to the limb, less is known about the molecular mechanisms that mediate this developmental event. Here, we examine the spatiotemporal distributions of the EphA4 receptor tyrosine kinase (RTK) and its cognate ligands, ephrin-A2 and ephrin-A5, on motor neurons, their axons and their pathways to the avian hindlimb to determine whether these molecules may influence axonal projections. The expression patterns of EphA4, ephrin-A2 and ephrin-A5 mRNAs and proteins are highly complex and appear to exhibit some overlap during motor axon outgrowth and pathfinding to the hindlimb, reminiscent of the co-expression of Eph RTKs and ephrins in the retinotectal system. EphA4, similar to the carbohydrate moiety polysialic acid, strikingly marks the main dorsal, but not ventral, nerve trunk after axon sorting at the limb plexus region. Our results suggest that EphA4 RTK and its ligands may influence axon fasciculation and the sorting of axons at the limb plexus, contributing to the correct dorsoventral organization of nerve branches in the hindlimb.

The time-dependent increase in the binding of benzo[a]pyrene to DNA through (+)-anti-benzo[a]pyrene-7,8-diol-9,10-epoxide in primary rat hepatocyte cultures results from induction of cytochrome P450IA1 by benzo[a]pyrene treatment.

The proportion and amount of benzo[a]pyrene (B[a]P) that binds to DNA through the carcinogenic (+)-anti-benzo[a]pyrene-7,8-diol-9,10-epoxide [(+)-anti-BPDE] increases with time of exposure to B[a]P in cell cultures derived from a number of species. Pretreatment of primary rat hepatocyte cultures for 12 h with 1 microgram B[a]P/ml medium increased the subsequent metabolism of [3H]B[a]P by 47% and [3H]B[a]P-DNA binding by 53% compared with acetone-pretreated hepatocytes. The amount of (+)-anti-BPDE bound to DNA in the B[a]P-pretreated hepatocytes increased 175%. B[a]P pretreatment also increased DNA-binding 2-fold in hepatocytes treated with [3H]7,8-dihydroxy-7,8-dihydro-B[a]P but had no effect on DNA binding in cells treated with anti-B[a]P-7,8-diol-9,10-epoxide. Western blotting showed that cytochrome P450IA1, which was not detectable prior to B[a]P treatment, was selectively increased by B[a]P treatment. A monoclonal antibody that specifically inhibits cytochrome P450IA1 reduced the binding of B[a]P to DNA by greater than 90% in microsomal preparations from B[a]P-pretreated hepatocytes. These results indicate that the time-dependent increase in the formation of (+)-anti-BPDE-DNA adducts results from an increase in the amount and proportion of B[a]P metabolized to this ultimate carcinogen by P450IA1 that is induced by the B[a]P treatment. The importance of P450IA1 induction by the B[a]P for its activation to this ultimate carcinogenic metabolite suggests that long-term exposure of cells to B[a]P could result in activation of a higher proportion of the B[a]P to the carcinogenic (+)-anti-BPDE.

An autoradiographic study of projections ascending from the midbrain central gray, and from the region lateral to it, in the rat.

Ascending projections from the midbrain central gray (CG) and from the region lateral to it were traced in the rat using tritiated amino acid autoradiography. Leucine or a cocktail of amino acids (leucine, proline, lysine, histidine, and tyrosine) were used as tracers. In addition to projections within the midbrain, ascending fibers follow three trajectories. The ventral projection passes through the ventral tegmental region of Tsai and the medial forebrain bundle to reach the hypothalamus, preoptic area, caudoputamen, substantia innominata, stria terminalis, and amygdala. There are labeled fibers in the diagonal bands of Broca and medial septum, and terminal labeling in the lateral septum, nucleus accumbens, olfactory tubercle, and frontal cortex. The dorsal periventricular projection terminates in the midline and intralaminar thalamic nuclei. The ventral periventricular projection follows the ventral component of the third ventricle into the hypothalamus, passing primarily through the dorsal hypothalamic area and labeling the rostral hypothalamus and preoptic area. Projections from the region lateral to the CG are similar, but exhibit stronger proximal, and weaker distal, projections. Rostral levels of the CG send heavier projections to the fields of Forel and the zona incerta, but fewer fibers through the supraoptic decussation, than do caudal levels. Ascending projections from the CG are both strong and widespread. Strong projections to the limbic system and the intralaminar thalamic nuclei provide an anatomical substrate for CG involvement in nociception and affective responses.

Subordination in male talapoin monkeys lowers sexual behaviour in the absence of dominants.

Three experiments assessed the consequences of social status for the socio-sexual behaviour and endocrine state of adult male talapoin monkeys (Miopithecus talapoin). In the first study, each of five males was individually placed into a group of adult females. Neither behavioural responses, nor plasma levels of testosterone, cortisol, or prolactin, predicted males' rank or hormone levels when all males were subsequently placed with these females. In the second study, each of four mixed-sex social groups lived continuously in a large cage for periods ranging from 9-15 months. There were marked differences between the behaviour and hormone levels of highest- and lowest-ranking males. In the third study, each highest- and lowest-ranking male from these groups was individually placed with females. Males that had experienced social subordination for long periods (9-15 months) showed infrequent sexual behaviour and had elevated levels of cortisol and prolactin. These results indicate that the experience of chronic social subordination is a strong predictor of how males will subsequently behave, since both the endocrine and behavioural effects of subordination persist even after the dominant males are removed.

Social influences on circulating levels of cortisol and prolactin in male talapoin monkeys.

Three captive groups of adult talapoin monkeys (Miopithecus talapoin), each with four males and four or five ovariectomized, estrogen-treated females, were observed. Behavioral interactions were recorded and levels of cortisol and prolactin were measured. In each group, males formed a linear dominance order, determined by the direction of spontaneous aggression; highest male rank was associated with frequent socio-sexual interactions and lowest rank with infrequent socio-sexual behavior. The first study compared males' cortisol and prolactin titers when all males were either housed with estrogen-treated females, or singly caged. The two lowest-ranking males of each group had elevated cortisol levels when group-housed; prolactin levels did not reflect these changes. In the second study, males of one group interacted with females when only the lowest-ranking, or the highest-ranking, female was made attractive (i.e., received estradiol), while the other females were present, but not estradiol-treated. Across these conditions (1) frequencies of some socio-sexual and aggressive behaviors changed, (2) cortisol levels increased in all males, and (3) prolactin levels decreased in three of four males. Dissociation of changes in cortisol and prolactin titers suggests that these hormones may be differentially responsive to social modifications, not simply reflecting a single intervening variable, such as "stress."

Effects of rank and novel females on behaviour and hormones in male talapoin monkeys.

Two social groups of captive talapoin monkeys (Miopithecus talapoin), each with three intact adult males and three or four ovariectomized, estrogen-treated adult females, were observed. Socio-sexual and aggressive interactions were recorded, and levels of testosterone, cortisol, and prolactin were measured in male serum. Cortisol and prolactin titers did not reflect male rank, nor did changes in one of these hormones parallel changes in the other. In both groups males formed a linear dominance hierarchy, defined in terms of the direction of aggression among animals. Highest male rank was associated with frequent socio-sexual interaction and elevated testosterone levels, even in the absence of ejaculations. Males in one group copulated with females, but no male in the other group copulated. All males of each group were then housed with all females of the other group which resulted in marked changes in males' behaviour; socio-sexual interactions increased in C group males and decreased in B group males. This illustrates the influence that females may have on male behaviour in general, and in particular outlines the potential for female dominance and the consequences this may have especially on reproductive behaviour.