Roles of melatonin in gonadal maturation of underyearling precocious male masu salmon

Testicular maturation of underyearling precocious male masu salmon (Oncorhynchus masou) is affected by photoperiod. It is accelerated by a short photoperiod (light-dark cycles of 8:16 h; LD 8:16) and delayed by a long photoperiod (LD 16:8). Circulating melatonin levels are high during the night and low during the day:the duration of the nocturnal elevation is longer under a short than under a long photoperiod, suggesting mediation of photoperiodic signals by melatonin. This study examined whether melatonin administration mimics short photoperiodic effects and whether it accelerates the testicular development of underyearling male masu salmon reared under a long photoperiod. Fish were randomly selected in June and were divided into two groups. They were reared under LD 16:8 (lights on 04:00-20:00 h) and fed pellets sprayed with melatonin (0.5 mg melatonin/kg body weight/day) or vehicle once a day at 11:00 h until October. The plasma melatonin profile of the melatonin-treated group was similar to that expected under a short photoperiod. Melatonin treatment had a stimulatory effect on the gonadosomatic index and pituitary gonadotropin (GTH) I contents. Plasma testosterone levels were significantly higher in the melatonin-treated group than in the control group in August. However, spermiation was observed in October in both groups and no significant differences were observed in GTH II contents in the pituitary in the two groups throughout the experiment. These results suggest that mimicking a short photoperiod by melatonin administration stimulated testicular development but did not completely activate the brain-pituitary-gonadal axis in precocious male masu salmon. Thus, melatonin is suggested to be one of the factors that mediates the transduction of photoperiodic information to the brain-pituitary-gonadal axis.

Positive and negative syndromes, and Borna disease virus infection in schizophrenia

The relationship between Borna disease virus (BDV) infection and positive and negative syndromes in schizophrenia was investigated. By nested RT-PCR and Western blotting, BDV-specific RNA and anti-BDV antibodies were examined in blood from 67 schizophrenic patients (DSM-III-R) in Japan, and the psychometric properties of the Positive and Negative Syndrome Scale (PANSS) were analyzed. There were significant (p < 0.05) differences in the composite index denoting the positive minus negative difference indicating a dominant contribution by negative items, and the proportion of negative type (positive minus negative value below zero) patients, between patients positive and negative for anti-BDV p24 antibodies. It is possible that BDV infection with induction of BDV p24 antibodies may be associated with negative syndromes in schizophrenic patients.

Cavitary pulmonary metastases of gallbladder cancer

We report a case of multiple cavitary pulmonary metastases of gallbladder cancer. Radiologically, every cavity displayed a very thin wall containing only air inside. The postmortem histopathological examination showed that: (1) the cavities were surrounded by normal alveoli; (2) these walls were composed mostly of adenocarcinoma cells; (3) necrotic or mucous substance was sparse in the cavity space; (4) cancer cells infiltrated along the surface of the alveolar septa, and (5) the morphology of the cancer cells of the gallbladder and the lung was the same. It seemed likely that the thin-walled cavities in the lung might result from central breakdown of the tumor and subsequent expectoration of debris through the connected airways.

Facilitatory roles of novel compounds designed from cyclopentenone prostaglandins on neurite outgrowth-promoting activities of nerve growth factor

Cyclopentenone prostaglandins (PGs) are known to arrest the cell cycle at the G(1) phase in vitro and to suppress tumor growth in vivo. However, their effects on neurons are unclear. Here, we report that some cyclopentenone PGs function as neurite outgrowth-promoting factors. They promoted neurite outgrowth from PC12 cells and from dorsal root ganglion explants but only in the presence of nerve growth factor (NGF). We refer to these PGs as neurite outgrowth-promoting PGs (NEPPs). Through study of the structure-function relationship of NEPP1-10 and related compounds, we found that the cross-conjugated dienone moiety of NEPPs was essential for promoting neurite outgrowth, and NEPP10 was concluded to be the best candidate for drug development. We also investigated the intracellular mechanism of the promotion by NEPPs and obtained evidence that immunoglobulin heavy chain binding protein/glucose-regulated protein 78 (BiP/GRP78) plays a role in the promotion, based on the following observations: Antisense nucleotides for BiP/GRP78 gene blocked the promotion of neurite outgrowth; BiP/GRP78 protein level increased in response to NEPPs; and overexpression of BiP/GRP78 protein by adenoviral gene transfer promoted the neurite outgrowth by NGF.

Exposure of normal monocyte-derived dendritic cells to human immunodeficiency virus type-1 particles leads to the induction of apoptosis in co-cultured CD4+ as well as CD8+ T cells

The depletion of immune T cells by human immunodeficiency virus type-1 (HIV-1) infection is a major mechanism involved in the pathogenesis of AIDS. Here, we examined a possible effector function of blood monocyte-derived dendritic cells (DCs) to induce apoptosis in bystander CD4+ and CD8+ T cells. The DCs were generated by culturing monocytes in the presence of granulocyte-macrophage colony-stimulating factor and interleukin-4. The DCs exposed to HIV-1 particles were co-cultured with healthy donor-derived blood T cells at a ratio of 1:20. Analyses by percent cell mortality, staining with propidium iodide and reactivity with Annexin V revealed the induction of apoptosis in both CD4+ and CD8+ target T cells. Further, this apoptosis occurred without stimulation with mitogens when the cell cycle of target T cells shifted from G0 to G1, probably due to the mitogenic effect of the DCs. Thus, induction of apoptosis in both CD4+ and CD8+ T cells occurred via interaction with DCs adsorbed with HIV-1 particles.

The influence of HLA genotyping compatibility on clinical outcome after cord blood transplantation from unrelated donors

We performed retrospective DNA typing of class I (A, B, Cw) and class II (DRB1, DQB1, DPB1) HLA alleles in 27 unrelated cord blood transplantation (CBT) cases donated from a single cord blood bank (Kanagawa Cord Blood Bank). The influence of HLA genotype matching on clinical outcome was evaluated. From Cox's model, we found that incompatibility of two or more HLA alleles between the donor and recipient of an unrelated CBT was suggested to be a risk factor for a worse event-free survival (EFS) (p = 0.04; RR, 4.06; 95% CI, 1.06-15.61). Furthermore, mismatches including HLA-DRB1 alleles had an adverse effect on EFS (p = 0.04; RR, 4.91; 95% CI, 1.01-24.02). For definite conclusions on the role of HLA allele typing in unrelated CBT, more accumulation of data and analysis will be required.

Increased frequency of surface IgA-positive plasma cells in the intestinal lamina propria and decreased IgA excretion in hyper IgA (HIGA) mice, a murine model of IgA nephropathy with hyperserum IgA

Because abnormalities of mucosal immunity have been suggested in human IgA nephropathy, we examined the involvement of mucosal immunity in IgA deposition to the kidney in hyper IgA (HIGA) mice, which was established as a mouse model for human IgA nephropathy with hyperserum IgA. The number of surface IgA+B220- lymphocytes in the intestinal lamina propria (LP) of HIGA mice increased 2.7-fold at 30 wk of age as compared with those at 10 wk of age, whereas normal mice did not show such increase. The surface IgA+B220- LP lymphocytes spontaneously secreted IgA in culture. Morphological studies showed that the surface IgA+B220- lymphocytes of murine intestinal LP are identical with plasma cells (PCs). About 20% of IgA+B220- PC in LP expressed both Mac-1 and CD19, suggesting that they may derive from peritoneal B-1 cells. Cell cycle study on intestinal IgA-PCs using bromodeoxyuridine revealed no difference between HIGA mice and normal mice, suggesting that the high frequency of IgA-producing PCs in HIGA mice is not due to enhanced proliferation or prolonged survival of IgA-producing PCs in LP. In addition, IgA secretion into the gut lumen of HIGA mice decreased drastically (to one forth) with aging. These data suggest that the increased number of intestinal IgA-producing PCs and the down-regulation of IgA excretion into the intestinal lumen might synergistically contribute to the hyperserum IgA in HIGA mice and resultant IgA deposition to the kidney.

Antibodies to Borna disease virus in infected adult rats: an early appearance of anti-p10 antibody and recognition of novel virus-specific proteins in infected animal brain cells

The time course for appearance of antibodies to Borna disease virus (BDV) major antigens, p40, p24, p18 and p10 were investigated in BDV-inoculated adult rats by Western blotting. Anti-p10 antibodies were detected in sera as early as anti-p40 and -p24 antibodies at four or five weeks after inoculation. Furthermore, in addition to these major antigens of BDV, the rat serum could detect additional 80-, 58-, 43-, 20-, and 16-kDa proteins in BDV-infected cultured cells and/or animal brain cells by Western blot analysis. Of these proteins, the 20- and 16-kDa proteins were shown to be related to p24 protein by their reactivity with anti-p24 monoclonal antibody. Interestingly, the 58- and 24-kDa were found only in BDV-infected animal brain cells but not in cultured cells. The results in this study could provide a useful information on the mechanism for the viral replication and pathogenesis.

Mutations occurring during serial passage of Japanese equine infectious anemia virus in primary horse macrophages

An attenuated equine infectious anemia virus (EIAV), named V26, was previously obtained after 50 passages of the Japanese virulent strain V70 in primary macrophage culture. To clarify the differences between both viruses, their full-length sequences were determined. There were higher mutations in S2 (6.15% amino acid difference) and LTR (10.7% nucleotide difference). The presumed initiation codon of the S2 gene was absent from the sequence of V26. There was a large insertion within the long-terminal repeat (LTR) U3 hypervariable region of V26. In addition, there were minor mutations in gag (1.22% amino acid difference), pol (1.05% amino acid difference) and env (1. 65% amino acid difference) regions, but no mutation in tat region. No mutations were observed in the principal neutralizing domain in the gp90. Thus, the mutations in the S2 and LTR might be the major target sites of mutation in EIAV during serial passages in vitro.

Treatment of cervical cord compression, caused by hereditary multiple exostosis, with laminoplasty: a case report

STUDY DESIGN

Case report.

OBJECTIVES

Successful excision of the exostosis within the spinal canal.

SUMMARY OF BACKGROUND DATA

Myelopathy caused by exostosis within the spinal canal developed in a 13-year-old boy with hereditary multiple exostosis.

METHODS

Spinous process-splitting laminoplasty with an ultrasonic knife was performed to remove the mass and minimize the possibility of postlaminectomy kyphosis.

RESULTS

The spinal canal exostosis with cervical cord compression was excised successfully with laminoplasty. After surgery there has been no recurrence of tumor, and the stability of the cervical spine has been preserved.

CONCLUSION

This is the first report of laminoplasty as a useful surgical approach for intraspinal exostosis to prevent postoperative cervical instability.

Isolation of Borna disease virus from human brain tissue

Serological and molecular epidemiological studies indicate that Borna disease virus (BDV) can infect humans and is possibly associated with certain neuropsychiatric disorders. We examined brain tissue collected at autopsy from four schizophrenic patients and two healthy controls for the presence of BDV markers in 12 different brain regions. BDV RNA and antigen was detected in four brain regions of a BDV-seropositive schizophrenic patient (P2) with a very recent (2 years) onset of disease. BDV markers exhibited a regionally localized distribution. BDV RNA was found in newborn Mongolian gerbils intracranially inoculated with homogenates from BDV-positive brain regions of P2. Human oligodendroglia (OL) cells inoculated with brain homogenates from BDV-positive gerbils allowed propagation and isolation of BDVHuP2br, a human brain-derived BDV. Virus isolation was also possible by transfection of Vero cells with ribonucleoprotein complexes prepared from BDV-positive human and gerbil brain tissues. BDVHuP2br was genetically closely related to but distinct from previously reported human- and animal-derived BDV sequences.

The monoclonal antibody TER-119 recognizes a molecule associated with glycophorin A and specifically marks the late stages of murine erythroid lineage

The antigen specificity of a rat monoclonal antibody TER-119 was investigated. In adult mice, TER-119 reacted with mature erythrocytes, 20-25% of bone marrow cells and 2-3% of spleen cells but not with thymocytes nor lymph node cells. In fetal haematopoietic tissues, 30-40% of d 10 yolk sac cells, 80-90% of d 14 fetal liver cells and 40-50% of newborn liver cells were reactive with TER-119. TER-119+ cells in adult bone marrow expressed significant levels of CD45 but not myeloid (Mac-1, Gr-1) or B-cell (B220) markers. Morphological examination and haematopoietic colony-forming assays for isolated TER-119+ cells revealed that TER-119 reacts with erythroid cells at differentiation stages from early proerythroblast to mature erythrocyte, but not with cells showing typical erythroid blast-forming unit (BFU-E) and erythroid colony-forming unit (CFU-E) activities. Erythroleukaemia cell lines do not express the TER-119 antigen even after stimulation with dimethylsulphoxide. TER-119 immunoprecipitated protein bands with molecular masses of 110 kDa, 60 kDa, 52 kDa and 32 kDa from erythrocyte membrane, whereas only a 52-kDa band was detected by TER-119 in Western blot analysis. Further molecular and cellular analyses indicated that the TER-119 antigen is a molecule associated with cell-surface glycophorin A but not with glycophorin A itself.

Overexpression of hemochromatosis protein, HFE, alters transferrin recycling process in human hepatoma cells

HFE is a MHC class 1-like protein that is mutated in hereditary hemochromatosis. In order to elucidate the role of HFE protein on cellular iron metabolism, functional studies were carried out in human hepatoma cells (HLF) overexpressing a fusion gene of HFE and green fluorescent protein (GFP). The expression of HFE-GFP was found to be localized on cell membrane and perinuclear compartment by fluorescent microscopy. By co-immunoprecipitation and Western blotting, HFE-GFP protein formed a complex with endogenous transferrin receptor and beta(2)-microglobulin, suggesting that this fusion protein has the function of HFE reported previously. We then examined the (59)Fe uptake and release, and internalization and recycling of (125)I-labeled transferrin in order to elucidate the functional roles of HFE in the cell system. In the transfectants, HFE protein decreased the rate of transferrin receptor-dependent iron ((59)Fe) uptake by the cells, but did not change the rate of iron release, indicating that HFE protein decreased the rate of iron influx. Scatchard analysis of transferrin binding to HFE-transfected cells showed an elevation of the dissociation constant from 1.9 to 4. 3 nM transferrin, indicating that HFE protein decreased the affinity of transferrin receptor for transferrin, while the number of transferrin receptors decreased from 1.5x10(5)/cell to 1. 2x10(5)/cell. In addition, the rate of transferrin recycling, especially return from endosome to surface, was decreased in the HFE-transfected cells by pulse-chase study with (125)I-labeled transferrin. Our results strongly suggest an additional role of HFE on transferrin receptor recycling in addition to the decrease of receptor affinity, resulting in the reduced cellular iron.

Hemophagocytosis by leukemic blasts in 7 acute myeloid leukemia cases with t(16;21)(p11;q22): common morphologic characteristics for this type of leukemia

BACKGROUND

In a previous study of a case of acute megakaryoblastic leukemia with t(16;21)(p11;q22), which displayed hemophagocytosis by leukemic blasts, the authors mentioned that the same type of morphology had been cited in the literature for 4 other cases of acute myeloid leukemia (AML) with the same translocation. This observation prompted the authors to examine more cases of AML with t(16;21)(p11;q22) for this morphology.

METHODS

The authors reviewed bone marrow smears for the presence of hemophagocytosis in 7 patients with AML identified as having t(16;21)(p11;q22).

RESULTS

The leukemias belonged to the FAB-M1/M7 (n = 5), M5b (n = 2), and contained phagocytic blasts in various percentages (< 0.2-36.7%). The blasts contained either single or multiple cytoplasmic vacuoles, in some of which the phagosomes were visible. The engulfed hemopoietic cells (red cells, erythroblasts, lymphocytes, and thrombocytes) were also noted in their cytoplasm. These observations confirmed that hemophagocytosis by leukemic blasts is a common and characteristic feature of this type of leukemia.

CONCLUSIONS

The study of 12 cases (the 7 cases described here and the previous 5 cases) strongly supports the hypothesis that hemophagocytosis by leukemic blasts is common and characteristic in this type of leukemia, which may be related to the specific chromosome aberration of t(16;21)(p11;q22).

Six months of maintenance chemotherapy after intensified treatment for acute lymphoblastic leukemia of childhood

PURPOSE

We postulated that intensification of chemotherapy immediately after remission induction might reduce the leukemic cell burden sufficiently to allow an abbreviated period of antimetabolite therapy.

PATIENTS AND METHODS

Three hundred forty-seven children (ages 1 to 15 years) with previously untreated acute lymphoblastic leukemia (ALL) were enrolled onto the Tokyo L92-13 study, which excluded patients with mature B-cell ALL and patients less than 1 year old. One hundred twenty-four patients were classified as standard risk, 122 as high risk, and 101 as extremely high risk, according to age, peripheral-blood leukocyte count, selected genetic abnormalities, and immunophenotype. All subjects received four drugs for remission induction, followed by a risk-directed multidrug intensification phase and therapy for presymptomatic leukemia in the CNS. Maintenance chemotherapy with oral mercaptopurine and methotrexate was administered for 6 months, with all treatment stopped by 1 year after diagnosis.

RESULTS

The mean (+/- SD) event-free survival (EFS) and overall survival rates for all patients were 59.5% +/- 3.4% and 81.5% +/- 2.2%, respectively, at 5. 5 years after diagnosis. EFS rates by risk category were similar (60. 2% +/- 6.0% for standard risk, 57.7% +/- 5.6% for high risk, and 62. 5% +/- 5.7% for extremely high risk), whereas overall survival rates differed significantly (91.2% +/- 2.7%, 80.0% +/- 4.1%, and 72.1% +/- 4.5%, respectively, P <.0001 by the log-rank test). There were 107 relapses. Eighty-five (79.4%) of these 107 patients achieved second complete remissions, with subsequent EFS rates of 61.5% +/- 7. 9% (standard risk), 42.6% +/- 8.1% (high risk), and 9.6% +/- 6.4% (extremely high risk). Of the five risk factors analyzed, only the response to prednisolone monotherapy among extremely high-risk patients proved important.

CONCLUSION

Early treatment intensification did not compensate for a truncated phase of maintenance chemotherapy in children with standard- or high-risk ALL. However, 6 months of antimetabolite treatment seemed adequate for extremely high-risk patients who were good responders to prednisolone and received intensified chemotherapy that included high-dose cytarabine early in the clinical course.

Gonadotropins and cytokines affect luteal function through control of apoptosis in human luteinized granulosa cells

The luteal phase in the normal human menstrual cycle is known to be about 14 days. The physiological mechanisms that regulate the corpus luteum remain to be clarified, although apoptosis is reported to be involved. This study was undertaken to investigate the regulation of luteal function by gonadotropins, cytokines, and PGs, concentrating attention on the incidence of apoptosis and its molecular mechanisms in cultured human luteinized granulosa cells collected at oocyte pick-up from patients undergoing in vitro fertilization and embryo transfer. Clusters of granulosa cells were pipetted in 0.1% hyaluronidase in phosphate-buffered saline. After cell separation by centrifugation using Ficoll-Paque, 1 x 104 viable cells/mL in RPMI 1640 medium with 10% FCS were used for experimentation. Substances added were FSH (100 ng/mL), hCG (100 ng/mL), LH (100 ng/mL), interleukin-1beta (IL-1beta; 10 ng/mL), transforming growth factor-beta1 (TGFbeta1; 10 ng/mL), macrophage colony-stimulating factor (MCSF; 10 ng/mL), tumor necrosis factor-alpha (TNFalpha; 10 ng/mL), and PGF2alpha (10 ng/mL). After 24-h culture at 37 C under 5% CO2 and air, cells were fixed with 4% neutral buffered formalin and stained with Hoechst 33258. Apoptotic bodies were counted under a fluorescence microscope, and immunostaining was performed using anti-Fas, Fas ligand, Bcl-2, Bax, and p53 antibodies. Incidences of apoptotic bodies in the group without substance addition were 0.7 +/- 0.2% (0 h), 5.9 +/-0.6% (24 h), and 7.9 +/- 1.2% (48 h); spontaneous increase was significant at the latter time points. Defining the incidence at 24 h as 100%, values after treatment were: FSH, 57%; LH, 84%; hCG, 44%; IL-1beta, 76%; TGFbeta1, 52%; M-CSF, 50%; TNFalpha, 177%; and PGF2alpha, 147%. Significant suppression was observed with FSH, hCG, TGFbeta1, and M-CSF (P < 0.01). On the other hand, significant induction occurred with TNFalpha and PGF2alpha (P < 0.01). On immunostaining, the incidence of stained cells with anti-Fas, Fas ligand, Bax, and p53 antibody was increased after 24-h incubation without addition. This was reduced by hCG, TGFbeta1, and M-CSF. No stained cells were observed with anti-Bcl-2 antibody before or after incubation. In conclusion, our results suggest that both gonadotropins (FSH and hCG) and cytokines (TGFbeta1 and M-CSF) may be involved in the support of luteal function via suppression of apoptosis, and that TNFalpha and PGF2alpha may contribute to ovarian dysfunction and/or luteal regression via its induction in human luteinized granulosa cells. Our results also suggest that Fas, Fas ligand, p53, and Bax may play roles in this apoptosis controlled by hCG, TGFbeta1, and M-CSF.

Detection of Borna disease virus in a pregnant mare and her fetus

A pregnant mare showing pyrexia, reduced appetite, ataxia and paresis was euthanized and examined for the presence of Borna disease virus (BDV). Her brain, showing multiple neuronal degeneration and necrosis with hemorrhage, and the histologically normal brain of the fetus were both positive for BDV RNA. The BDV nucleotide sequences were identical in the mare and fetus in the second open reading frame (ORF). This is the first report of the possible vertical transmission of BDV in a horse.

Highly variable sequences in the env V3 region of HIV type 1 distributing among Thai carriers from 1995 to 1997

The amino acid sequences of the Env V3 region of HIV-1 subtype E in Thailand were highly variable in the samples obtained from 1995 to 1997, compared with the previously reported sequences in samples obtained from 1990 to 1993. The sequences of the V3 region in the samples from five provinces in Thailand revealed that the variability was much higher in the samples from Bangkok and Ubonrachathani than in those from Chiangmai, Prathumthani, and Trang. There was no apparently different level of diversity at the V3 region in the samples from symptomatic and asymptomatic individuals. The V3 loop motif in most (66.7%) of the samples was GPGQ, although this motif was more heterogeneous in the samples from Bangkok and Ubonrachathani than in those from the other three provinces. The N-linked glycosylation sites in the V3 region among these samples were relatively conserved. There was no apparent difference in the presence of positively charged amino acids at positions 306 and 320 between the samples from symptomatic and asymptomatic individuals.

Sex chromosomal analysis of spermatozoa from infertile men using fluorescence in situ hybridization

PURPOSE

To confirm an association between male infertility and chromosome aberrations of spermatozoa, we demonstrated the frequency of numerical abnormalities of spermatozoa from infertile men with abnormal semen parameters compared with fertile controls.

METHOD

Sperm cells from 10 infertile patients were investigated for disomy rates of sex chromosomes and chromosome 18 and diploidy by fluorescence in situ hybridization (FISH). All patients showed oligoasthenozoospermia with sperm counts 3-20 x 10(6)/ml and motile rates 0-40%.

RESULTS

Regarding XY disomy, a significantly higher frequency was found in 8 of 10 patients as compared to normal fertile men. The disomy rates of chromosome 18, XX, YY, and diploidy rate were not increased.

CONCLUSIONS

There is an association between male infertility and embryo with aneuploidy of sex chromosomes. Counseling about possible genetic risks should be provided to the infertile couples planning assisted reproduction treatment.

Detection of Epstein-Barr virus in salivas and throat washings in healthy adults and children

It is well known that Epstein-Barr virus (EBV) is excreted from oral regions in the patients with infectious mononucleosis. We analyzed the prevalence of EBV in saliva and throat washings from healthy people in Japan by the polymerase chain reaction assay. EBV DNA was detected in 43 (90%) of the 48 throat washings from healthy adults (21 to 57 years old) and in 35 (38%) of the 93 salivas from healthy children (0 to 6 years old). The percentages of the EBV DNA-positive ratio in salivas increased in proportion relative to the increase of the children's ages. EBV type 1 was predominant and was detected in 86 and 94% of adults and children, respectively. Umbilical cord lymphocytes were transformed by some throat washings from EBV seropositive donors. EBV DNA was detected in throat washings from two healthy adults whose EBV antibody was not detected. In both cases, higher amounts of EBV DNA were detected in their peripheral blood mononuclear cells than in those of other, EBV antibody-positive donors. These results demonstrated the incidence of EBV excretion in oral regions of healthy individuals in Japan and defined a novel type of EBV infection in healthy adults.

Fusion of uninfected T-cells occurs with immature HIV-1 protease-mutant, but not morphologically similar protease inhibitor derived particles

Protease inhibitors are widely used in the treatment of human immunodeficiency virus type 1 (HIV-1)-infected individuals and show a drastic effect on the reduction of virus load. We previously reported that doughnut-shaped, protease-defective gp120-containing HIV-1 particles from an L-2 cell clone, carrying a provirus with mutations at the pol (protease), env (gp41) and nef genes, rapidly and more effectively induces virus particle-mediated syncytia formation of uninfected T-cells, than a parental wild-type laboratory strain of HIV-1 (LAI). In this study, we examined the possibility of whether enhanced syncytia formation is mediated by morphologically similar doughnut-shaped particles obtained after treatment of LAI-infected cells with the protease inhibitors L-689, 502, DMP-323, RO-31-8959, and KNI-272. Utilizing such protease inhibitor-induced particles and a clone of MOLT-4 cells, we could not detect any enhancement of syncytia formation, over that seen with wild-type LAI particles. This result should alleviate concerns of patients on highly active antiretroviral therapy (HAART), that protease inhibitors might accelerate progression of the disease through enhanced production of defective, 'immature'-appearing particles.

Replication ability in vitro and in vivo of equine infectious anemia virus avirulent Japanese strain

An attenuated equine infectious anemia virus (EIAV), V26, was previously prepared by 50 passages of the Japanese virulent strain V70 in primary horse macrophage culture. The horses inoculated with this V26 virus were shown to raise neutralizing antibodies against V70 without any viremia. Here, we investigated the in vitro and in vivo replication ability of V26. Comparison of the long-terminal repeat (LTR) sequences between V26 and V70 revealed a large insertion within the LTR U3 hypervariable region of V26. V26 with the mutation in the LTR showed much higher promoter activity in vitro than V70. This is consistent with the much higher replication rate of V26 in horse primary macrophage cultures compared with V70. In sharp contrast, we failed to identify the V26-specific LTR sequence by PCR, at least in sequential samples of plasma or peripheral blood mononuclear cells derived from three horses until day 62 after V26 inoculation. In contrast, antibody responses to EIAV were observed in all horses. The results suggest that the replication ability of V26 in vivo is extremely low. When one of the horses was subsequently challenged with cell-associated V70, it was found that the horse became PCR positive for EIAV. There was no LTR mutation in EIAV genome in samples periodically prepared from the V70-challenged horse. Thus it was suggested that the LTR mutation in EIAV, which occurs during serial passage in vitro, affects EIAV replication in vitro and in vivo.

High prevalence of Borna disease virus in domestic cats with neurological disorders in Japan

A total of 15 (T-1-T-15) domestic cats with neurological disorders in Tokyo area were examined for association with Borna disease virus (BDV). None had detectable antibodies to feline immunodeficiency virus (FIV), feline leukemia virus, feline infectious peritonitis virus and Toxoplasma gondii, and only cat T-8 had detectable antibody to FIV. Serological and molecular epidemiological studies revealed a significantly high prevalence of BDV infection in these cats: antibodies against BDV p24 and/or p40 proteins in 10/15 (66.7%) and p24 and/or p40 RNA in peripheral blood mononuclear cells in 8/15 (53.3%). Further, in situ hybridization and immunohistochemistry analyses of the autopsied brain samples derived from one of the cats (T-15) revealed BDV RNA predominantly in neuronal cells in restricted regions, such as olfactory bulb and medulla of cerebrum. Thus, BDV is present in Japanese domestic cats with neurological disorders at a high prevalence.

Effects of recombinant thrombopoietin on the growth of murine primitive and committed hematopoietic progenitors in serum-free culture

BACKGROUND

The aim of the present study was to determine the effect of thrombopoietin (Tpo) in combination with other cytokines on the growth of murine megakaryocytic, granulocyte-macrophage, erythroid and primitive hematopoietic progenitor cells, excluding possibilities of synergistic effects by serum factor(s).

METHODS

Serum-free clonogenic assay systems were used for assay of colony forming units in megakaryocytes (CFU-Mk), colony forming units in granulocytes-macrophages (CFU-GM), burst-forming units in erythrocytes (BFU-E) in marrow of normal mice and of high proliferative potential colony forming cells in 5-fluorouracil-treated marrow.

RESULTS

Serum-free culture enabled megakaryocyte colony growth by recombinant murine (rm) Tpo and this was synergistically supported with rm interleukin (IL)-3, rm stem cell factor (SCF) or recombinant human (rh) erythropoietin (Epo). Recombinant human IL-6, rhIL-11 and rm granulocyte-macrophage colony stimulating factor (GM-CSF) showed synergistic effects with rmTpo only in the presence of serum. Recombinant murine IL-3 or rmSCF increased the large colonies and mixed-type colonies containing other populations, suggesting that these cytokines promoted the proliferation of immature populations of CFU-Mk. The rmTpo enhanced the growth of granulocyte-macrophage (GM) colonies stimulated by rmGM-CSF or rmIL-3 and erythroid bursts by rhEpo, with or without rmIL-3. The rmTpo also significantly increased HPP colonies in synergy with rmIL-3 only in the presence of serum or rmSCF.

CONCLUSION

Serum-free culture is valuable for evaluating synergistic effects of cytokines and Tpo acts not only on megakaryocytic progenitors but also on granulocyte-macrophage, erythroid and primitive progenitor cells in combination with other cytokines, such as rmIL-3 and rmSCF. However, serum or SCF was required for enhancement of the colony growth of primitive progenitors by Tpo.