Patterns of hobo elements and their effects in natural populations of Drosophila melanogaster in Japan.

We studied the dynamics of hobo elements of Drosophila melanogaster in Japan with the goal of better understanding the invasion and evolution of transposons in natural populations. One hundred and twenty-six isofemale lines and 11 older stocks were tested for the presence and genetic phenotype of hobo elements. The oldest H strain, containing complete and deleted hobo elements, is Hikone-H (1957), but Hikone-R (1952) has no hobo-homologous sequences. The findings suggest that the hobo element invaded Japanese populations in the mid-1950s, at about the same time as the P element invasion in Japan. This chronology is consistent with the hypothesis of a recent worldwide hobo element invasion into D. melanogaster in the mid-1950s. In recently collected populations, H degrees strains (low hobo activity and high repression potency) are predominant, whereas H+ strains (high hobo activity and high repression potency) are predominant in the Sakishima Islands, the most southwestern islands of the Japanese archipelago. H' strains (high hobo activity and low repression potency) were first found in limited island populations. Japanese populations have not only full-size hobo elements and 1.5 kb Th elements but also characteristic deletion derivatives (1.6 and 1.8 kb XhoI fragments) that we have named Jh elements. These results are consistent with transgenic experiments with complete hobo elements, in which populations evolved to H+ or H degrees via H', and in which 1.8 kb fragments appeared. We conclude that hobo elements invaded the central region of Japan, spread to the far islands, and that the invasion is currently at an intermediate, nonequilibrium stage.

Modification of urinary secretion of 8-hydroxy-2'-deoxyguanosine and serum ACTH concentration following repetitive parabolic flights.

It is important to clarify the molecular mechanisms of physiological responses of the human body to changes in gravity. Previous reports demonstrated that gravity-changing stress increases the human urinary concentration of 8-hydroxy-2'-deoxyguanosine (8-OHdG). However, it has yet to be clarified whether repetitive parabolic flight modulates the urinary concentration of 8-OHdG after exposure to gravity-changing stress. In the present study, the effects of the number of previous experiences with parabolic flight on urinary excretion of 8-OHdG and concentration of serum ACTH were examined in 12 healthy volunteers.

Some molecular and inhibitory specifications of a dipeptidyl carboxypeptidase from the polychaete Neanthes virens resembling angiotensin I converting enzyme.

Dipeptidyl carboxypeptidase (DCP) from the polychaete Neanthes virens, resembling mammalian angiotensin I converting enzyme (ACE), was studied to discover some of its molecular and inhibitory properties, as the first evidence of these in a marine invertebrate. Amino acid and carbohydrate contents were analyzed. The N-terminal amino acid sequence of N. virens DCP was (NH2)D-E-E-A-G-R-Q-W-L-A-E-Y-D-L-R-N-Q-T-V-L-. Peptide maps of N. virens DCP from lysyl endopeptidase digestion were different from rabbit p-ACE. The far-ultraviolet circular dichroic spectra of N. virens DCP indicated that the secondary structure of this enzyme seemed to be an alpha-helical structure and was similar to that of rabbit p-ACE, but the near-ultraviolet circular dichroic spectra of N. virens DCP indicated that the aromatic amino acid residue circumambience of this enzyme was different from rabbit p-ACE. The effects of several reagents for chemical modification of amino acids on the activity of N. virens DCP were tested. Arg, Tyr, Glu, and/or Asp, His, Trp, and Met caused loss of the activity. In addition, the IC50 and Ki values for a well-known ACE inhibitor, Val-Tyr, which was a competitive inhibitor of N. virens DCP, were 263 and 20 microM, respectively. These results suggested that N. virens DCP is different from mammalian ACE in the molecular and inhibitory properties, although the same substrate specificity was demonstrated in a previous paper.

Increase in ultraviolet sensitivity by overexpression of calpastatin in ultraviolet-resistant UVr-1 cells derived from ultraviolet-sensitive human RSa cells.

Human RSa cells are highly sensitive to apoptotic-like cell death by ultraviolet irradiation (UV) while UVr-1 cells are their variant with an increased resistance to UV. Three days after UV at 10 J/m2, the viability of RSa cells was approximately 17% while that of UVr-1 cells was 65%. This different survival might reflect apoptotic cell death since apoptosis-specific DNA ladder was more clearly observed in RSa cells than in UVr-1 cells after UV. Addition of ALLN/calpain inhibitor I to the culture medium after UV resulted in similar survival (14 - 18%) between RSa and UVr-1 cells. Immunoblot analysis showed down-regulation of protein kinase CTheta, Src, Bax and mu-calpain after UV was more prominent in UVr-1 than in RSa cells. Activated mu-calpain appeared within 1 h post-UV only in UVr-1 cells. The expression of calpastatin, a specific endogenous inhibitor of calpain, was higher in RSa than in UVr-1 cells. To further examine the role of calpain in UV-induced cell death, cDNA of human calpastatin was transfected into UVr-1 cells. The results showed that overexpression of calpastatin suppressed down-regulation of Src, mu-calpain and Bax. Concomitantly, colony survival after UV was reduced in calpastatin-transfected cells as compared to vector control cells. Our results suggest that activation of calpain might account for, at least in part, the lower susceptibility to UV-induced cell death in UVr-1 cells.

Changes in levels of serum erythropoietin, serum iron and unsaturated iron binding capacity during chemotherapy for lung cancer.

BACKGROUND: The serum erythropoietin level increases markedly during chemotherapy for leukemia. A number of hypotheses have been built for the mechanism, none of them satisfactory. Difficulty in evaluating bone marrow activity hampers the elucidation. Therefore, we focused on patients who had non-hematological cancer and no evidence of bone marrow suppression. METHODS: Twelve patients, who had lung cancer (four with small cell cancer and eight with non-small cell cancer) and who had not undergone any chemotherapy, were studied. During chemotherapy, we measured serum erythropoietin, serum iron, unsaturated iron binding capacity and hemoglobin concentration in these patients. RESULTS: The serum erythropoietin level before chemotherapy (10.8 +/- 7.4 mU/ml) was within the normal range but the peak values after the first treatment (73.4 +/- 90.4 mU/ml) increased in all patients. In the patients with small cell cancer, a transient but marked increase in erythropoietin value (204.6 +/- 167.3 mU/ml) was observed after each session of chemotherapy while hemoglobin concentration decreased gradually. Throughout treatments, elevation of the serum iron concentration and concomitant reduction of unsaturated iron binding capacity were observed after each session of chemotherapy. They regained their original values whilst the serum erythropoietin level decreased after each chemotherapy session was completed. CONCLUSIONS: It is suggested that the suppression of erythroid marrow by chemotherapeutic agents causes the changes in serum erythropoietin level during chemotherapy in patients with lung cancer.

Search for genes responsible for UV susceptibility of human cells: involvement of syndecan-1 in UV resistance.

UVr-1 UV-resistant cells were established from UV-sensitive human RSa cells. We looked for genes expressed differentially between UVr-1 and RSa cells using PCR-based mRNA differential display to elucidate the molecular mechanisms underlying UV resistance. The transcription levels of syndecan-1 mRNA were increased in UVr-1 cells compared with those of RSa cells. Syndecan-1 is a transmembrane heparan sulfate proteoglycan and associates with cell adhesion and the cytoskeleton. Flow cytometric analysis using anti-syndecan-1 monoclonal antibody revealed that syndecan-1 was more abundant in UVr-1 cells than in RSa cells. The MTT method revealed that UVr-1 cells treated with the antibody showed higher sensitivity to UV cell killing than mock-treated cells. Studies using antisense oligonucleotides for syndecan-1 showed that antisense-treated UVr-1 cells became sensitive to UV cell killing. Thus, syndecan-1 might be involved in UV resistance in UVr-1 cells.

Changes in serum erythropoietin and the reticulocyte count during chemotherapy for leukemias.

We serially determined serum erythropoietin (Epo) and the reticulocyte count in patients with various types of leukemia during chemotherapy. Serum Epo increased soon after the initiation of chemotherapy and decreased after the termination of therapy irrespective of the types of leukemia or treatment regimen. However, it did not stay at low level but fluctuated. The reticulocyte count, on the other hand, showed a transient rise while serum Epo level descended. The value of serum Epo when increased was higher than the value expected from hemoglobin concentration; this finding was similar to that in aplastic anemia. These results suggest that myelosuppression is a major factor for the increase in serum Epo level during leukemia chemotherapy.

[Two patients with acute promyelocytic leukemia whose relapse was noted by cytodiagnosis of middle ear discharge].

Patient 1 was a 36-year-old male and diagnosed as APL in April 1989, and treated with BHAC-DMP and BHAC-AMP. In January 1990, a diagnosis of exudative otitis media was made, but intractable. In June, left facial paralysis appeared and cytodiagnosis of the discharge from the middle ear confirmed leukemic cells. Otitis media and facial paralysis improved after high dose Ara-C, but developed again 5 months later. The condition improved after high dose Ara-C and irradiation of the temporal bones. In September 1992, he died of recurrence but no aggravation in facial paralysis or otitis media. Patient 2 was a 24-year-old female and diagnosed as APL in July 1989, and treated with BHAC-DMP. In May 1990, exudative otitis media was appeared. In July, recurrence was observed but improved by high dose Ara-C. In October, otitis media was aggravated again, and cytodiagnosis confirmed leukemic cell infiltration. She was treated with high dose Ara-C and irradiation of the temporal bones, then achieved complete remission. Maintenance therapy was continued until August 1992, she has been alive. When exudative otitis media developed during the course of leukemia, cytodiagnosis of the discharge from the middle ear should be performed. High dose Ara-C and irradiation of the temporal bone were effective.

[Molecular evidence for a single clonal origin in a patient with multiple myeloma and non-Hodgkin's lymphoma].

A 49-year old man was admitted in November 1989, because of anemia, abnormal shadowing on chest X ray and hyperproteinemia. Biclonal gammopathy (IgG kappa + IgA kappa) was shown in serum, and Bence Jones protein in urine. The bone marrow examination showed an increased number of abnormal plasma cells (15.7%) and no evidence of lymphoma, A diagnosis of multiple myeloma (MM) was made. In April 1990, while the patient was treated with the modified M2 regiman, swelling of the right cervical lymph node was observed. Lymph node biopsy revealed that he had non-Hodgkin's Lymphoma (:NHL, diffuse, mixed, B cell type). He was retreated with the CHOP regimen for both disease, but died of respiratory failure in October. 1991. To establish the clonal origin of this case of concominant MM and B-cell NHL, the immunoglobulin gene rearrangements in his lymph node and bone marrow were analyzed. Southern blot analysis with the JH probe and Ck probe showed one common band and one different band in the two samples. Our data suggest that two B-cell malignancies may have arisen from a single B-cell progenitor.

[High-dose chemoradiotherapy combined with recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) followed by autologous peripheral blood stem cell transplantation (PBSCT) in a case of refractory acute myelogenous leukemia (AML)].

Recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) stimulates the growth of myeloid leukemic cells and increases their susceptibility to cell-cycle specific agents. We treated a patient with acute myelogenous leukemia (AML) in a state of second resistant relapse, with high-dose chemoradiotherapy combined with rhGM-CSF (total body irradiation: TBI 3Gy x 4, on days -8 & -7; cytosine arabinoside: Ara-C 3g/m2, iv, q12h, on days -5-2; rhGM-CSF 250 micrograms/m2/day, cont.iv, on days -5-2) followed by autologous peripheral blood stem cell transplantation (PBSCT). In this case, rhGM-CSF enhanced the proliferation of leukemic cells in vitro. The test dose of rhGM-CSF (84 micrograms/m2 over 8 hours) also promoted leukemic cell proliferation in vivo, resulting in an increase in the percentage of leukemic cells in the peripheral blood and reappearance of chromosomal aberrations in the bone marrow. The toxicity of rhGM-CSF-combined conditioning regimen included fever and mild liver damage. The patient achieved a complete remission lasting for 2 months, then relapsed. The rhGM-CSF-combined conditioning regimen was tolerated by this patient, but further studies will be required to confirm not only its safety but also its effectiveness in the treatment of refractory AML.