Cloning of a cDNA encoding an importin-alpha and down-regulation of the gene by light in rice leaves

The import of nuclear proteins into nuclei begins with recognition of nuclear localization signal-harboring proteins and binding to a nuclear pore targeting complex. A cDNA for an importin-alpha protein, a subunit of the complex, was isolated from rice plants. The amino acid sequence deduced from the nucleotide sequence of the cDNA exhibited a high homology to those of importin-alpha proteins from many organisms such as Arabidopsis thaliana, Saccharomyces cerevisiae, human, mouse, Xenopus laevis and Drosophila melanogaster. Down-regulation of the transcription by light was shown in the leaves of light- and dark-grown seedlings by RNA blot analysis. The down-regulation was specific to leaves, whereas no light effect was observed in root tissues or calli, in which higher levels of the transcript were detected.

Classification of Lactobacillus helveticus strains by immunological differences in extracellular proteinases

Polyclonal antibodies against an extracellular proteinase of Lactobacillus helveticus CP53 were raised. The antibodies reacted with a 170-kDa enzyme with activity and a 53-kDa protein that seemed to be a degradation product of the 170-kDa proteinase from results of immunoblotting. The antibodies reacted also with a 45-kDa extracellular proteinase of L. helveticus CP790. However, monoclonal antibodies to the CP790 proteinase did not react with the proteinase of L. helveticus CP53. Seventeen strains of L. helveticus were tested for immunological reactivity with the two kinds of antibodies. The strains all had the same reactivity as either strain CP53 or strain CP790. Eleven strains with the 45-kDa proteinase were identified as L. helveticus biovar jugurti because they did not ferment maltose, four other strains with the 170- and 53-kDa proteins were identified as L. helveticus biovar helveticus because they fermented maltose. The remaining two strains dit not fit this pattern; they had both the 170- and 53-kDa proteins, but classification by their sugar utilization showed them to be L. helveticus biovar jugurti.

A method for analyzing the qualitative and quantitative aspects of gene expression: a transcriptional profile revealed for HeLa cells

A number of strategies have been devised by which differentially expressed genes in different cell types or tissues can be identified. We here report an efficient method to analyze the qualitative and quantitative aspects of transcripts and to construct an extensive gene expression profile in any kind of cell or tissue of interest. This method enables us to analyze the composition of mRNA species, reflecting gene activities, by measuring the frequency of appearance of concatamerized 17mer cDNA mini-fragments, which are proportional to the abundance of mRNA. As compared with a related method previously described by others, we can analyze approximately 3-4 bp longer cDNA fragments derived from amounts of total RNA as small as 1 microg. Using this technique we examined 10 100 cDNA mini-fragments from HeLa cells and constructed a gene expression profile consisting of 3665 genes. This method should thus provide an overall indication of gene activities and a rational means for monitoring gene fluctuation in different cells or tissues at different stages of development, in normal and disease states.

Clinical characteristics of patients with metastatic breast cancer with complete remission following systemic treatment

BACKGROUND

Patients with metastatic breast cancer (MBC) have variable clinical courses. The purpose was to describe the clinical characteristics of MBC patients with complete remissions (CR) following systemic treatment.

METHODS

We analyzed 315 consecutive MBC patients treated with several types of systemic treatments at the National Cancer Center Hospital between January 1988 and December 1993.

RESULTS

The median survival time (MST) and median progression-free survival were 28.0 and 17.1 months, respectively. Forty patients were defined as 'first-CR' following initial or second-line systemic treatment and the majority of them had a good performance status, low number of metastatic sites and low incidence of liver involvement. Nine of 40 patients with first-CR continued progression-free 5 years after beginning systemic treatments. The major sites of metastasis were the lung and bone and there were no cases with liver metastasis. Five patients received standard doxorubicin-containing combination chemotherapy with or without tamoxifen. Two of these nine patients remain progression free in first-CR. Three of them remained in first-CR after 5 years and died of progressive breast cancer and two others died of unrelated causes. Two patients relapsed after obtaining a first-CR for at least 5 years and remain alive with active metastatic disease. The MST and median progression-free survival of nine patients were 10.6 and 9.0 years, respectively. These nine patients represented 22.5% of all first-CR patients and 3.2% of the total patients.

CONCLUSIONS

Although MBC is commonly recognized to be an incurable disease, a small percentage of patients clearly are alive and progression free for prolonged periods after initiation of systemic treatments.

Structurally well-defined macrophage activating factor derived from vitamin D3-binding protein has a potent adjuvant activity for immunization

Freund's adjuvant produced severe inflammation that augments development of antibodies. Thus, mixed administration of antigens with adjuvant was not required as long as inflammation was induced in the hosts. Since macrophage activation for phagocytosis and antigen processing is the first step of antibody development, inflammation-primed macrophage activation plays a major role in immune development. Therefore, macrophage activating factor should act as an adjuvant for immunization. The inflammation-primed macrophage activation process is the major macrophage activating cascade that requires participation of serum vitamin D3-binding protein (DBP; human DBP is known as Gc protein) and glycosidases of B and T lymphocytes. Stepwise incubation of Gc protein with immobilized beta-galactosidase and sialidase efficiently generated the most potent macrophage activating factor (designated GcMAF) we have ever encountered. Administration of GcMAF (20 or 100 pg/mouse) resulted in stimulation of the progenitor cells for extensive mitogenesis and activation of macrophages. Administration of GcMAF (100 pg/mouse) along with immunization of mice with sheep red blood cells (SRBC) produced a large number of anti-SRBC antibody secreting splenic cells in 2-4 days. Thus, GcMAF has a potent adjuvant activity for immunization. Although malignant tumours are poorly immunogenic, 4 days after GcMAF-primed immunization of mice with heat-killed Ehrlich ascites tumour cells, the ascites tumour was no longer transplantable in these mice.

Are young women in Japan at high risk for eating disorders?: Decreased BMI in young females from 1960 to 1995

The height, weight and body mass index (BMI) of Japanese males and females aged from 6 to 24 years between 1960 and 1995 were studied. From 1960 to 1995 in males of all ages and in females aged 6-14 years height, weight and BMI increased. In females aged 15-24 years, the height increased and the weight slightly increased, but the BMI gradually decreased from 21.5 in 1960 to 20.5 in 1995. Over the last 35 years adolescent and young adult women have become thinner. Dieting to be slim has become much more prevalent among young women. These findings suggest that young females in Japan have decreased their BMI by dieting in order to become slim. If this tendency persists, with regard to a close relationship between restrained eating or dieting and eating disorders, Japanese young women have a much greater risk of developing eating disorders.

A novel importin alpha from rice, a component involved in the process of nuclear protein transport

In eukaryotes, nuclear proteins that are transported into nuclei have nuclear localization signals (NLSs), which are recognized by proteins called importin alpha. We isolated a rice cDNA, #61L, and the corresponding gene that encodes a protein, which shows significant homology to the importin alpha. Although the encoded protein had only 23-27% amino acid identity to the importin alphas from various organisms including plants, the fusion protein with glutathione S-transferase showed a specific binding activity to the NLS of SV40 T-antigen. These results suggest that the rice #61L protein is a novel importin alpha in plants.

Inhibition of HIV-1 replication by foldback triple-helix forming oligonucleotides

Replication of retroviral RNA into double-stranded DNA is catalyzed by reverse transcriptase (RT). The polypurine tract (PPT) serves as a primer for plus-strand DNA synthesis and is highly conserved among HIV-1. The PPT region is a possible target for triple-helix formation. Here, we show the effects of triple-helix formation by analyses of melting temperature and gel shift using a foldback triplex-forming-oligonucleotides (FTFOs). We found that the FTFOs containing phosphorothioate groups at the 3'- and 5'-ends, or inside the hairpin loop, exhibited greater exonuclease resistance than the unmodified FTFOs. Several triplex oligonucleotides have thermal stability. The abilities of the FTFOs (DsDG-37) containing the guanosine in place of the cytidine in the third Hoogsteen base-pairing strand to inhibit HIV-1 replications were examined. The FTFOs (DsDG-37) inhibit the replication of HIV-1 more efficiently than the FTFOs (DsD-37) indicating sequence-specific inhibition of HIV-1 replication.

Serum level of eosinophil cationic protein in patients with chronic cough: relationship to blood eosinophils and airway hyperresponsiveness

We measured the serum level of eosinophil cationic protein (ECP), determined the blood eosinophil count, and assessed pulmonary function by spirometry and airway responsiveness to methacholine in 80 patients with a cough lasting longer than 3 weeks without an obvious cause. The serum level of ECP was above the cutoff value of 15.7 ng/mL (mean + 2 SD in 105 healthy control adults) in 30 (37.5%) of 80 patients (high-serum-ECP group). The blood eosinophil count was significantly higher in the high-serum-ECP group than in the normal-serum-ECP group (p < 0.01). The cumulative dose of methacholine causing a 35% decrease in respiratory conductance (PD35Grs) was significantly lower in the high-serum-ECP group than in the normal-serum-ECP group (p < 0.001). The serum concentration of ECP was correlated with the blood eosinophil count and the PD35Grs (r = 0.59, p < 0.001 and r = -0.48, p < 0.001, respectively). These findings suggest a possible role for serum level of ECP in management of patients with chronic cough.

High SDF-1 expression in HIV-1 carriers does not correlate with CD8+ T-cell-mediated suppression of viral replication

Stromal cell-derived factor 1 (SDF-1) inhibits T-cell tropic (T-tropic) HIV-1 infection in vitro. In this study, we examined the regulatory role of SDF-1 on HIV-1 replication in peripheral blood mononuclear cells (PBMC) of HIV-infected individuals. We found that the amount of SDF-1 mRNA in freshly isolated PBMC of HIV-1 carriers was higher than in healthy donors. Moreover, PBMC from some asymptomatic carriers (ACs) exhibited high levels of SDF-1 mRNA expression. The level of SDF-1 expression in PBMC did not correlate with the magnitude of CD8+ T-cell-mediated suppression of HIV-1 among ACs SDF-1 inhibited HIV-1 replication at the viral entry step, whereas a single-cycle HIV-1 infection system showed that the major part of the CD8+ T-cell-mediated suppression occurs after intracellular penetration of the virus. Our results suggest that SDF-1 acts as a suppressor of virus replication in a CD8+ T-cell-independent mechanism in HIV-infected individuals.

Enhancement of human immunodeficiency virus type 1 (HIV-1) infection via increased membrane fluidity by a cationic polymer

Cationic polymers are known to have potent activity against bacteria, but their effects on viral activity have been little studied. We investigated the effect of one such polymer, polyethyleneimine (PEI), on HIV-1 infection. Although virus-cell binding was significantly inhibited by PEI, HIV-1 infection in human T-cell lines such as MT-4 and MOLT-4 was accelerated conversely when the drug treatment was carried out, after the virus had attached to the cells or PEI was simultaneously added to the virus and cell culture system. This paradoxical effect of PEI on HIV-1 infection was examined using HIV-1 chronically infected cells (MOLT-4/HIV-1). Dissociation of the glycoprotein gp120 (as revealed by exposure of transmembrane protein gp41) from MOLT-4/HIV-1 cells and the resultant fusion of these cells was shown to be induced by the addition of PEI. Accordingly, it was suggested that the binding inhibition of HIV-1 to CD4-positive cells by PEI was due to the shedding of gp120 from HIV-1 particles, and this PEI rather promoted membrane fusion between the virus and cells leading to the enhancement of HIV-1 infection. Similarly, dissociation of gp120 from MOLT-4/HIV-1 was also induced by sCD4. The effect of these reagents on changes in membrane fluidity was evaluated by polarization (p) measurements, and it was observed that the acceleration of membrane fluidity occurred only in the PEI system. Therefore, it is likely that PEI accelerates HIV-1 infection by facilitating virus entry into the host cells through an increase in membrane fluidity.

Elevated serum levels of the soluble form of gp130, the IL-6 signal transducer, in HTLV-1 infection and no involvement of alternative splicing for its generation

By using an ELISA, increased levels of the soluble form (sgp130) of gp130, the IL-6 signal transducer, were detected in the sera of various HTLV-1-associated conditions (HC, ATL, HAM) as compared to normal healthy individuals. Sgp130 levels seemed to be correlated with disease severity. The 94 KD of sgp130 was specifically precipitated in the sera of HTLV-1-infected patients as revealed by Western blot analysis. A reverse transcriptase (RT)-polymerase chain reaction (PCR) method was used to detect the message for transmembrane (TM) lacking gp130 in mRNA isolated from peripheral blood mononuclear cells (PBMCs) of patients infected with or without HTLV-1 and those of various hematopoietic cell lines. Two PCR products, 648 and 507 bp were observed in the PBMCs from HTLV-1-infected patients. But the 507 by PCR product was not detected in the PBMCs from normal healthy individuals and HTLV-1-positive cell lines although the 648 bp product was equally expressed. A nucleotide sequence analysis of the 507 bp fragment showed deletion of the 141 bp at the region spanning from nucleotide 1702 (G) to 1842 (T) of the 648 bp product that matched completely with a conventional gp130 molecule. This deleted region was located upstream of the transmembrane (TM) domain, but not within the TM region itself. However, no frame shift was observed. These results indicate that the generation of sgp130 may not be due to an alternative splicing mechanism.

Preoptic gonadotropin-releasing hormone (GnRH) neurons innervate the pituitary in teleosts

In most teleosts, there are three groups of gonadotropin-releasing hormone (GnRH) neurons. In this study we addressed the question of GnRH neuronal innervation of the pituitary in the dwarf gourami and the tilapia using immunocytochemistry combined with biocytin tract tracing. Biocytin was applied to the pituitary attached to the brain in vitro. Similar results were obtained in both species. GnRH neurons retrogradely labeled with biocytin were observed only in the preoptic area. These results indicate that preoptic GnRH neurons innervate the pituitary. Negative labeling of biocytin in the terminal-nerve and midbrain GnRH neurons suggests that these two GnRH neuronal populations do not project to the pituitary. Biocytin-positive but GnRH-negative neurons were also observed in the preoptic area and the ventromedial parts of the hypothalamus, suggesting neuropeptidergic and aminergic innervation of the pituitary besides GnRH.

Evidence of vascular growth associated with laser treatment of normal canine myocardium

BACKGROUND

Transmyocardial laser revascularization is a new therapy for patients with refractory angina. Although clinical studies suggest that transmyocardial laser revascularization decreases angina and may improve regional blood flow, the underlying mechanisms are not elucidated. We hypothesized that one mechanism may relate to stimulation of vascular growth in laser-treated regions.

METHODS

Transmyocardial laser revascularization channels were made with holmium:yttrium-aluminum garnet or carbon dioxide lasers in eight normal canine hearts; animals were sacrificed 2 to 3 weeks later and examined for vascular density and for evidence of smooth muscle proliferation.

RESULTS

The original channels were infiltrated by granulation tissue with associated vascularity. Vascular growth was stimulated immediately surrounding the channel remnant as evidenced by an increase in the number of vessels (approximately twice that of the control region) and an increase in the number of vascular cells staining positive for markers of cellular proliferation.

CONCLUSIONS

Transmyocardial laser revascularization leads to local vascular growth as early as 2 weeks after treatment. It remains to be determined whether this mechanism contributes to increased regional blood flow or to clinical benefits associated with this novel form of therapy.

Angiogenesis is enhanced in ischemic canine myocardium by transmyocardial laser revascularization

OBJECTIVES

This study sought to test whether transmyocardial laser revascularization (TMLR) stimulates angiogenesis in an animal model of chronic ischemia.

BACKGROUND

TMLR relieves angina and may also improve blood flow in patients who are not candidates for traditional therapies. The mechanisms of these benefits are not fully defined.

METHODS

Ischemia was created in 14 dogs by proximal left anterior descending coronary ameroid constrictors. TMLR was performed in the anterior wall (approximately 1 channel/cm2) of seven dogs; the remaining dogs served as the ischemic control group. Myocardial blood flow was measured (colored microspheres) at rest and during chemical stress (adenosine) in the acute setting and after 2 months.

RESULTS

TMLR did not influence blood flow in the acute setting. After 2 months, resting blood flow increased comparably in the anterior wall in both groups to approximately 80% of normal. However, the TMLR-treated dogs demonstrated an approximately 40% increase in blood flow capacity during stress in the ischemic territory compared with untreated dogs (left anterior descending coronary artery/left circumflex coronary artery flow 0.53+/-0.16 in the control group vs. 0.73+/-0.08 in TMLR animals, p < 0.05). Vascular proliferation, assessed by bromodeoxyuridine incorporation and proliferating cell nuclear antigen positivity in endothelial and smooth muscle cells was about four times greater in the TMLR group than in the control group (p < 0.001). The density of vessels with at least one smooth muscle cell layer was approximately 1.4 times greater in the myocardium surrounding the TMLR channel remnants than in control ischemic tissue (p < 0.001).

CONCLUSIONS

In this canine model of chronic ischemia, TMLR significantly enhances angiogenesis as evidenced by the increased number of vessels lined with smooth muscle cells, markedly increased vascular proliferation and increased blood flow capacity during stress.

[Surgical treatment for hepatocellular carcinoma: liver resection using transplantation techniques]

Ex situ partial liver resection was performed in 2 patients with hepatocellular carcinoma (HCC) with Child A-liver cirrhosis that was untreatable by conventional liver resection techniques. In both cases, an extended left lobectomy was first performed, and then the autologous lateral segment was transplanted after removing segment 4 (or + a part of segment 5, 8) together with the tumor by the bench procedure. Although there might have been no difference in preoperative liver function in these cases, the postoperative course was quite different. The first case was successful with an uneventful postoperative course, but, the second case went into postoperative liver failure and the patient died of multiple organ failure on the 20th postoperative day. The cause of liver failure in the second case might be attributable to: 1) prolongation of cold preservation time for the bench procedure (196 min); or 2) over reduction of the native remnant liver (right lobe) due to resection of the huge tumor. In conclusion, the technique using ex situ partial liver resection and transplantation of the remnant section of the liver might be a useful method to extend surgical treatment for some cases of HCC untreatable by conventional liver resection. However, the indications should be carefully considered in each case, since graft damage can occur rapidly during the bench procedure due to combined liver cirrhosis.

Endovascular embolization of a renal artery aneurysm using interlocking detachable coils

A 51-year-old woman with a renal artery aneurysm was successfully treated with endovascular embolization using interlocking detachable coils. The parent vessel was spared, leading to preservation of the uninvolved portion of the kidney.

Downsizing of an HIV-cell fusion inhibitor, T22 ([Tyr5,12, Lys7]-polyphemusin II), with the maintenance of anti-HIV activity and solution structure

T22 ([Tyr5,12,Lys7]-polyphemusin II) has been shown to have strong anti-human immunodeficiency virus (HIV) activity comparable to that of 3'-azido-2',3'-dideoxythymidine (AZT). T22, an 18-residue peptide amide, takes an antiparallel beta-sheet structure that is maintained by two disulfide bridges. Herein we synthesized several shortened analogs of T22 in order to search for a more suitable lead compound. A 14-residue analog having one disulfide bridge, TW70 (des-[Cys8,13, Tyr9,12]-[D-Lys10, Pro11]-T22), was found to have highly potent activity comparable to that of T22, and to take an antiparallel beta-sheet structure similar to that of T22. This indicates that the molecular size of T22 can be reduced without loss of activity or significant change in the secondary structure, and that TW70 may represent a novel lead compound. Furthermore, modifying the N-terminal alpha-amino group of TW70 with a fluoresceinthiocarbamoyl group, and the epsilon-amino group of D-Lys8 at the turn portion with a 5-aminopentanoyl group remarkably increased the selectivity index (50% cytotoxic concentration/50% effective concentration).

Force-velocity relation of sliding of skeletal muscle myosin, arranged on a paramyosin filament, on actin cables

To investigate in vitro ATP-dependent sliding of regularly arranged myosin molecules on actin filaments, we prepared thick hybrid filaments in which myosin molecules isolated from rabbit skeletal muscle were arranged around the paramyosin core (length, 10-20 micron; diameter, </=0.2 micron) obtained from a molluscan smooth muscle. A single to a few thick hybrid filaments were attached to a polystyrene bead (diameter, 4.5 micron; specific gravity, 1.5) and made to slide on actin filament arrays (actin cables) in the internodal cell of an alga, mounted on the rotor of a centrifuge microscope. The bead was subjected to centrifugal forces serving as external loads to the ATP-dependent actin-myosin sliding. The maximum unloaded sliding velocity of the thick filament attached-bead (mean, 3.4 micron/s; 20-23 degrees C) was significantly higher than that of the bead coated with randomly oriented myosin molecules reported previously. The steady-state force-velocity (P-V) relations obtained were qualitatively similar to those in intact skeletal muscle fibers. These results indicate that this in vitro motility assay system retains the basic characteristics of contracting skeletal muscle fibers, and that it may be effectively used to study mechanisms underlying the steady-state P-V characteristics of ATP-dependent actin-myosin sliding using various recombinant myosins produced in nonmuscle cells.

Pharmacokinetic disposition and arthropathic potential of oral ofloxacin in dogs

We examined the relation between the pharmacokinetic disposition and arthropathic potential of ofloxacin, a new quinolone antibacterial agent, using both male immature (3-month-old) and mature (18-month-old) beagles. Ofloxacin was orally administered to these dogs at 20 mg/kg once daily for 8 consecutive days, and the animals were killed 2 h after the last treatment. Serum ofloxacin concentrations were repeatedly measured on days 1 and 7 by use of high-performance liquid chromatography (HPLC), and pharmacokinetic parameters were calculated. In addition, on day 8, the drug concentrations in the joint synovial fluid and humeral and femoral condyles were measured. Clinico-pathological tests of blood and serum or histopathological examination of bone specimens were also performed. Arthropathy was macroscopically observed in the cartilage surface of all immature dogs, but not in mature dogs. There were, however, no noticeable differences in pharmacokinetic parameters between the two age groups of dogs or between single and 7-day treatments. In contrast to the occurrence of arthropathic lesions, the synovial fluid and condylar drug concentrations in immature dogs was equal to or lower than those in mature dogs, suggesting that the pharmacokinetic disposition of ofloxacin may not be essential for cartilage lesions.