The diversity and radiation of the largest monophyletic animal group on New Caledonia (Trichoptera: Ecnomidae: Agmina).

In area, New Caledonia is the smallest of the world's 25 official biodiversity hotspots, but in many taxonomic groups, the island has the highest concentration of species on earth, particularly so in the freshwater insect order Trichoptera. This study aims at applying molecular data and morphology for estimating the real species diversity of the genus Agmina on New Caledonia and investigating potential effects of ultramafic rock substrate on diversification. A dated molecular phylogeny was applied to study diversity and diversification related to geological substrate using the dispersal-extinction-cladogenesis model, diva and Bayesian ancestral character reconstruction. More than 47 species (>63%) were unknown to science. Initial radiation occurred on ultramafic substrate followed by several independent dispersal events to nonultramafic substrate. The rate of shift from ultramafic to nonultramafic substrate was significantly higher than the rate of shift in the opposite direction, indicating a possible cost associated with living on ultramafic substrate.

BUILDING INFRASTRUCTURE LEADING TO DIVERSITY PROGRAM AT XAVIER UNIVERSITY OF LOUISIANA, PROJECT PATHWAYS.

Xavier University of Louisiana (XULA) is the only historically Black and Catholic institution of higher education in the United States. XULA's mission focuses on "the promotion of a more just and humane society" by educating students in a diverse learning environment. Even though Xavier's reputation in the sciences attracts many of the best and brightest students in the nation, the University also continues to provide an excellent educational opportunity to many students who, due to socioeconomic disparities, lack the appropriate preparation for college. The ultimate goal of Project Pathways, the National Institutes of Health (NIH)-funded BUILD (Building Infrastructure Leading to Diversity) Program at Xavier, is to increase the number of students who enter graduate programs in biomedical disciplines, successfully earn terminal degrees, and enter the biomedical research workforce. Xavier's plan to meet this challenge is based on a holistic approach, providing an integrated and coordinated student support and research skills training network. This coordinated effort cuts across academic departments in biomedical disciplines, academic support offices that include the Student Academic Success Office (SASO), the Office of Career Services (OCS), and the Center for Undergraduate Research and Graduate Opportunity (CURGO), as well as the Center for the Advancement of Teaching and Faculty Development (CAT+FD) for faculty support and mentor training. This work seeks to counter the regular practice at higher education institutions that have yet to address the importance of integrated programming across academic programs, student support programs, and research programs. This lack of coordinated and integrated programming often leads to duplication of efforts and ineffective use of resources. Xavier's BUILD program intentionally provides mechanisms and safeguards to ensure that coordination and integration occur at all levels. The overall hypothesis of Project Pathways is that when in a systematic way underrepresented minorities are provided with: early awareness and deepening exposure to biomedical careers;supportive relationships for students as they move through the pathway;suitable infrastructure; andmeaningful student engagement in biomedical research experiences and adequate research resources, a higher number will succeed in first entering, and later successfully completing graduate programs, leading to increased diversity in the biomedical research workforce. Preliminary assessment results are very encouraging; these results show higher course pass rates and better student preparation overall. The Project Pathways' initiatives can be replicated at other institutions with similar goals.

Nuclear magnetic resonance solution structure of truncated human GRObeta [5-73] and its structural comparison with CXC chemokine family members GROalpha and IL-8.

The three-dimensional structure of a novel four amino acid truncated form of the CXC chemokine GRObeta [5-73] isolated from bone marrow stromal cells with potent hematopoietic and anti-infective activities has been determined by two-dimensional (1)H nuclear magnetic resonance (NMR) spectroscopy in solution. On the basis of 1878 upper distance constraints derived from nuclear Overhauser effects (NOE) and 314 dihedral angle constraints, a group of 20 conformers representing the solution structure of the human GRObeta [5-73] was computed with the program DYANA. At the concentrations used for NMR study, GRObeta [5-73] forms a dimer in solution that is architectured by a six-stranded antiparallel beta-sheet (residues 25 to 29, 39 to 44, 49 to 52) and a pair of helices (residues 58 to 68) with 2-fold symmetry, while the C terminus of the protein is disordered. The average of the pairwise root-mean-square deviations of individual NMR conformers relative to the mean coordinates for the backbone atoms N, C(alpha) and C' of residues 5 to 68 is 0.47 A. Overall, the global fold of GRObeta [5-73] is similar to that of the previously reported NMR structure of GROalpha and the NMR and X-ray structures of interleukin-8. Among these three CXC chemokines, GRObeta [5-73] is most similar in structure to GROalpha. Significant differences between GRObeta [5-73], GROalpha and interleukin-8 are in the N-terminal loop comprising residues 12 to 19. The N-terminal arm containing the conserved ELR motif and the loop of residues 30 to 38 containing the GPH motif are different among these three CXC chemokines. The structural differences in these two regions may be responsible for the specificity of the receptor binding and biological activity of different chemokines.

Cloning and functional characterization of a novel human CC chemokine that binds to the CCR3 receptor and activates human eosinophils.

Eotaxin has been found to bind exclusively to a single chemokine receptor, CCR3. Using expression sequence tag screening of an activated monocyte library, a second chemokine has been identified; it was expressed and purified from a Drosophila cell culture system and appears to only activate CCR3. Eotaxin-2, MPIF-2, or CKbeta-6, is a human CC chemokine with low amino acid sequence identity to other chemokines. Eotaxin-2 promotes chemotaxis and Ca2+ mobilization in human eosinophils but not in neutrophils or monocytes. Cross-desensitization calcium mobilization experiments using purified eosinophils indicate that eotaxin and MCP-4, but not RANTES, MIP-1alpha, or MCP-3, can completely cross-desensitize the calcium response to eotaxin-2 on these cells, indicating that eotaxin-2 shares the same receptor used by eotaxin and MCP-4. Eotaxin-2 was the most potent eosinophil chemoattractant of all the chemokines tested. Eotaxin-2 also displaced 125I-eotaxin bound to the cloned CCR3 stably expressed in CHO cells (CHO-CCR3) and to freshly isolated human eosinophils with affinities similar to eotaxin and MCP-4. 125I-Eotaxin-2 binds with high affinity to eosinophils and both eotaxin and cold eotaxin-2 displace the ligand with equal affinity. Eotaxin and eotaxin-2 promote a Ca2+ transient in RBL-2H3 cells stably transfected with CCR3 (RBL-2H3-CCR3) and both ligands cross-desensitized the response of the other but not the response to LTD4. The data indicate that eotaxin-2 is a potent eosinophil chemotactic chemokine exerting its activity solely through the CCR3 receptor.

Crystal structure of Staphylococcus aureus tyrosyl-tRNA synthetase in complex with a class of potent and specific inhibitors.

SB-219383 and its analogues are a class of potent and specific inhibitors of bacterial tyrosyl-tRNA synthetases. Crystal structures of these inhibitors have been solved in complex with the tyrosyl-tRNA synthetase from Staphylococcus aureus, the bacterium that is largely responsible for hospital-acquired infections. The full-length enzyme yielded crystals that diffracted to 2.8 A resolution, but a truncated version of the enzyme allowed the resolution to be extended to 2.2 A. These inhibitors not only occupy the known substrate binding sites in unique ways, but also reveal a butyl binding pocket. It was reported that the Bacillus stearothermophilus TyrRS T51P mutant has much increased catalytic activity. The S. aureus enzyme happens to have a proline at position 51. Therefore, our structures may contribute to the understanding of the catalytic mechanism and provide the structural basis for designing novel antimicrobial agents.

Cortical connections of areas 17 (V-I) and 18 (V-II) of squirrels.

Connections of visual cortex in squirrels were investigated by placing WGA-HRP injections, and in some cases fluorescent dyes, into area 17 (V-I) or area 18 (V-II). Results were related to architectonic fields determined in brain sections cut parallel to the surface of manually flattened cortex and to limited microelectrode mapping data. Injections in area 17 provided evidence for 1) a patchy pattern of horizontal intrinsic connections extending 1-2 mm from the injection site; 2) uneven, widely distributed connections with area 18 (V-II) and adjoining occipital-temporal (OT) cortex; and 3) callosal connections of large portions of area 17 with the 17/18 border zone. While restricted locations in area 17 had uneven interconnections over several mm of area 18, more rostral locations in area 17 related to more rostral locations in area 18, demonstrating a topographic tendency. Injections in area 18 revealed 1) zones of discontinuous connections with area 17 that followed a topographic pattern, 2) patches of intrinsic connections that spread over distances of up to 6-8 mm from the injection site; 3) two zones of uneven connections with OT cortex suggesting the locations of at least two visual areas, OTr and OTc; 4) connections with limbic cortex rostromedial to areas 17 and 18; 5) sparse connections with regions of temporal cortex lateral to OT; and 6) uneven callosal connections with area 18 and OT cortex. The widespread and unevenly distributed intrinsic callosal interconnection patterns of areas 17 and 18 contrast with the restricted excitatory receptive fields of neurons and the retinotopic patterns of representation in these fields. Although physiological evidence is presently lacking, the patchy connections suggest that areas 17 and 18 in squirrels are modularly organized.

Kinetics of micronuclei induced by 125IdU in cells of two lines.

The kinetics of the formation of cells carrying micronuclei (MN) after one doubling time (td) incorporation of 125I-iododeoxyuridine (125IdU) to Chinese hamster ovary (CHO) and rat anterior pituitary tumor (GC) cells was studied. Uptake of 125IdU by cells of both cell lines was linearly dependent on the concentration of extracellular 125I activity. The postlabeling time-dependent decrease in cellular activity of 125IdU was exponential in CHO cells and approximately linear in GC cells. The maximum yield of MN was seen during the second and third td after 125IdU incorporation. The frequency of cells with micronuclei increased monotonically with dose in the interval (1, 40) 125I decays cell-1td-1. The dose-response relationship could be fitted by straight lines with slopes of 1.0 (CHO) and 1.2 (GC) on the subinterval (1, 10) and of 0.6 or 0.5, respectively, for the subinterval (10, 40). Below one 125I decay cell-1td-1, the mean frequency of micronucleated binuclear cells was significantly lower than (CHO) or equal to (GC) the control. On average, one 125I decay/cell induced 0.95 +/- 0.5% (CHO) or 1.0 +/- 0.5% (GC) of micronucleated binuclear cells.

Ureteral obstruction by shotgun pellet seven years after injury.

Ureteral obstruction by an extrinsic object is rare. We herein report a case of renal colic caused by a shotgun pellet lodged in the ureter seven years after the injury. Computerized tomography scan and antegrade pyelogram demonstration were obtained.

Study of intravesical mitomycin C in patients with multiple prior occurrences of superficial bladder cancer.

A limited course of intravesical mitomycin C was tested in 12 patients who had at least three, and an average of six, occurrences of superficial bladder cancer, and were at high risk for subsequent recurrences. After intravesical chemotherapy, recurrence rates were significantly less than rates prior to chemotherapy.

Management of simple renal cysts during percutaneous nephrostolithotomy.

Simple renal cysts can coexist with renal stones. Percutaneous removal of these stones requires special considerations. We describe the management of 2 patients with this problem and propose a simple logarithm.

Experience with potency preservation during radical prostatectomy. Significance of learning curve.

Potency preservation after radical prostatectomy is relatively new. The efficacy of this procedure has not been widely documented. Twenty-four patients with full potency underwent nerve-sparing radical prostatectomy. A total of 12 patients retained potency after surgery. Analysis of data reveals there is a learning curve in doing this procedure, and once the initial learning phase is over good results can be obtained in a select group of patients.

Kinetics of micronucleus induction by 125I-labelled thyroid hormone in hormone-responsive cells.

Two cell lines, CHO and GC, different in their tissue origin, were investigated with the aim of discovering the correlation between the level of 125I-T3 binding and chromosomal damage induced by 125I decay. Incubation of cells with 125I-T3 has been performed in two exposure schedules: continuous incubation for one to six cell cycles and a pulse-chase schedule involving exposure for one cell cycle. The cellular uptake of 125I-T3, its compartmentization and kinetics were different in the two cell lines. GC cells contained about 7 times more 125I-T3 than CHO cells when incubated with the same external 125I activity concentration (74 kBq of 125I-T3 ml-1 medium). Approximately 70% of the cellular 125I-T3 was found in nuclei of GC cells and only 5% in the nuclei of CHO cells. During the long-term incubation of GC cells with 74 kBq of 125I-T3 ml-1 medium, the 125I activity concentration in cells and their nuclei initially decreased by a half, and thereafter reached a plateau after the third doubling time. In CHO cells and nuclei a very slow linear increase of 125I activity was observed. In GC cells, micronucleus frequency was found to be correlated with nuclear 125I activity. One cell cycle pulse labelling with 74 kBq of 125I-T3 ml-1 medium caused a significant enhancement of micronucleus frequency above the control level during six doubling times, with a maximum at the first post-labelling doubling time. In GC cells continuously incubated with 74 kBq of 125I-T3 ml-1 medium, the micronucleus frequency increased with the incubation time. A model of T3 receptor-dependent dose delivery to nuclei of GC cells continuously incubated with 125I-T3 is proposed. The frequency of micronuclei in the CHO cell line continuously incubated with 125I-T3 did not differ significantly from the control, whereas in the pulse-chase schedule the mean frequency of micronucleated binuclear cells was lower during 4 post-labelling doubling times (significantly at the first and second post-labelling doubling time and insignificantly at the later doubling times) than in the control. Incubation of GC cells with various activity concentrations in medium for four cell cycles resulted in a linear increase of 125I activity in cells and nuclei; however, with a saturation in the region of highest 125I-T3 concentrations used. The frequency of binuclear cells bearing micronuclei was linearly dependent on the nuclear 125I-T3 concentration.

Chromosome damage induced by decay of 3H and 125I incorporated into DNA of Chinese hamster cells.

The present study was undertaken to compare the frequency of chromatid-type aberrations in Chinese hamster cells with previous results on accumulation of unrepaired DNA-strand breaks after incorporation of 3H-TdR or 125IUdR into DNA. A linear-quadratic function was fitted by the weighted-least-square method to the data on yield of chromatid aberrations at different dpm values. Based on a significant linear response at low doses, RBE for 125I in relation to 3H was calculated for (i) chromatid breaks (17 +/- 6), (ii) the sum of isochromatid breaks and chromatid exchanges (21 +/- 9), and (iii) the total number of chromatid aberrations (18 +/- 5). Analogously, the RBE for accumulation of DNA-strand breaks was determined (13 +/- 6). Our results are consistent with the assumption that chromosomal aberrations mainly originate from unrepaired DNA-strand breaks.

A direct assay for detection of chemically induced changes in the rejoining kinetics of radiation induced DNA strand breaks.

A simple and sensitive procedure for testing various chemicals affecting DNA repair is presented. Cells, either labelled with [3H]thymidine or [14C]thymidine, were drug-treated or used as references cells. Both cell populations were irradiated with 5 Gy. The number of DNA breaks were determined, after mixing of drug-treated and reference cells of different labelling, at various intervals by the DNA unwinding technique and the drug-dependent DNA breaks were calculated. The drugs benzamide, 3-aminobenzamide, novobiocin and 9-beta-D-arabinofuranosyladenine (araA), all known to affect DNA repair, were used to study their effect on the number of DNA strand breaks with the presented technique. It was found that the assay improved the accuracy in determining the influence of DNA repair inhibitors compared to indirect measurements.

Differential response of excision proficient and deficient L5178Y cells to UVC irradiation and benzamide.

L5178Y-R and L5178Y-S cells differ in sensitivity to UVC radiation (D0 values: 2.8 and 9.0 J m-2 respectively, exposure in Fischer's medium). The UVC sensitivity is related to the excision repair ability. Benzamide (Bz), an inhibitor of adenosine diphosphoribosyl transferase (ADPRT), does not modify the lethal effect of UVC radiation in L5178Y-R cells, whereas it sensitizes L5178Y-S cells. The content of NAD+ after irradiation decreases only in the latter cells and this decrease can be prevented by 2 mM Bz treatment. In agreement with the survival data, in L5178Y-R cells neither the proportion of abnormal cells nor the frequency of chromatid aberration are affected by 2 mM Bz treatment, in contrast with L5178Y-S cells. Bz slightly reverses inhibition of 3H-thymidine incorporation only in L5178Y-S cells, but it does not affect the proportions of cells in the different phases of the cell cycle in either cell strain after UVC exposure. These data could be taken as an indirect indication of the involvement of ADPRT in DNA repair in UVC-irradiated L5178Y-S cells. However, the increase in the number of DNA strand breaks in UVC-exposed, Bz-treated cells compared with UVC-exposed untreated cells is the same in both L5178Y strains.

5-Iododeoxyuridine-125I incorporation in vivo after exposure to a 50 Hz magnetic field.

CBA male mice were continuously exposed or sham-exposed to 50 Hz magnetic fields (MF) for 54 hours. Cell proliferation was studied by measuring the incorporation of 125IUdR (5-iododeoxyuridine) in whole body and organs such as thymus, thyroid gland, heart, lung, kidney, liver, spleen, testis, stomach, caecum, small intestine and colon. No significant differences were found either in body weights or weights of organs in the MF-exposed animals compared with controls. The incorporation of 125I activity in the whole body and in the organs did not differ between MF-exposed and sham-exposed control animals. In conclusion, the results showed no effects on cell proliferation in mice exposed to a continuous 50 Hz MF, with a flux density of 14 mu T peak-peak (p-p) for 54 hours, at least not detectable with 125IUdR as a tracer during the last 30 hours.

Effects of exposure to 50Hz or 20kHz [corrected] magnetic fields on weights of body and some organs of CBA mice.

Males from mouse litters exposed to 50Hz magnetic fields (MF) during the fetal stages right up to 280 days of age, showed a significantly lower body weight as well as kidney and liver weights compared with control animals. These results were not found in females. Adult mice exposed to MF for 140 days showed a significantly lower growth. Similar effects were seen in younger male mice exposed for 60 days. After 90 days exposure kidney and liver weights were significantly lower than controls. Young male mice exposed only for a few days showed a trend towards decreased body weight compared with controls. Using a 20kHz MF, young male mice showed the opposite pattern after 60 days of exposure. In conclusion, we found that the effects depended on exposure time. Young mice and males were found to be more sensitive. Finally, the effects were larger at 50 Hz than at 20 kHz.

DNA damage induced in brain cells of CBA mice exposed to magnetic fields.

DNA migration, using single cell gel electrophoresis (comet assay), was studied on brain cells of CBA mice exposed continuously to 50 Hz, 0.5 mT magnetic fields (MF) for 2 hrs, 5 days or 14 days. No differences were observed in the groups MF-exposed for 2 hrs and 5 days compared with controls. However, in the group exposed to MF for 14 days, a significantly extended cell DNA migration was observed (0.02 < p < 0.05). These changes together with results from previous studies indicate that magnetic fields may have genotoxic effects in brain cells.

DNA damage, cell kinetics and ODC activities studied in CBA mice exposed to electromagnetic fields generated by transmission lines.

CBA mice were exposed outdoors to 50 Hz electromagnetic fields (EMF), with a flux density of about 8 microT rms (root mean square), generated by a 220 kV transmission line. Assays were performed in order to investigate, the possible genotoxic effects after 11, 20 and 32 days of exposure, as well as the effects on body weight, leukocytes, erythrocytes, and the level of ornithine decarboxylase (ODC) activity in spleen and testis. DNA migration was studied on brain cells by single cell electrophoresis (comet assay). After 32 days of exposure a highly significant change of the tail/head ratio of the comets was observed (p < 0.001), showing DNA-damage. Further, a decreased number of mononuclear leukocytes (0.02 < p < 0.05) was observed in mice EMF-exposed for 20 days. In summary, our data indicate that transmission lines of this type may induce genotoxic effects in mice, seen as changes in the DNA migration. These results might have an important implication for health effects.

Radiocaesium transfer to man from moose and roe deer in Sweden.

Studies of radiocaesium in the forest ecosystems in Sweden resulted in aggregated transfer factors quantified for the transfer of 137Cs from soil to moose and roe deer. These aggregated transfer factors were 0.02 m2 kg-1 for moose and 0.05 m2 kg-1 for roe deer. There seems to be no decrease in the 137Cs activity concentrations in moose harvested in our research area and therefore we suggest the use of the physical half-life of 137Cs (30 years) as the effective ecological half-life. The time-integrated transfer of 137Cs from the Chernobyl fall-out to man by moose in Sweden was calculated and found to be 115 GBq, corresponding to 1500 man Sv for moose. The time-integrated transfer by roe deer to man was estimated to be between 25-48 GBq, corresponding to 327-620 man Sv for roe deer. The annual transfer of 137Cs to man by moose has varied between 2.0-2.7 GBq, corresponding to 27-34 man Sv. Depending on the group studied, the mean annual transfer of 137Cs can be calculated to be from about 250 to 43,000 Bq. For example, the mean annual transfer of 137Cs by moose to hunters and their families in Gävle commune, the most affected commune in Sweden, was estimated to be about 26,000 Bq, corresponding to 0.34 mSv.