Clonal expansion but lack of subsequent clonal deletion of bacterial superantigen-reactive T cells in murine retroviral infection

Several studies have suggested that activation-induced apoptosis of Ag-specific CD4+ T cells leads to depletion of this subset during HIV infection. The bacterial superantigen, staphylococcal enterotoxin A (SEA), is known to induce activation-induced apoptosis in the TCR V beta-bearing CD4+ T cells in the periphery after clonal expansion of these cells. The murine retroviral model of AIDS (MAIDS), which is induced by LP-BM5 murine leukemia virus, shares many common features with HIV infection in humans, except that CD4+ T cells increase progressively in susceptible strains. In this study, we challenged SEA to MAIDS mice and examined whether this retrovirus affects the fate of the SEA-reactive CD4+ T cells in vivo. At 4 wk post-infection with LP-BM5 murine leukemia virus, clonal expression and subsequent deletion of SEA-reactive CD4+V beta 3+ T cells occurred normally after SEA administration, whereas in vitro proliferative responses were severely impaired. At 8 wk postinfection, the in vivo expansion of CD4+V beta 3+ T cells was evident, but not followed by clonal deletion, as late as 14 days after SEA administration. This expanding subset in the infected mice expressed the Fas Ag in the same amount as the same subset in uninfected controls. These findings suggest that activation-induced apoptosis of superantigen-reactive CD4+ T cells is interfered with in vivo during the course of MAIDS, which is not attributable to underexpression of the Fas Ag by the CD4+ T cells.

Increased Fas antigen expression in murine retrovirus-induced immunodeficiency syndrome, MAIDS

The Fas antigen (Fas), which is a cell surface protein belonging to the tumor necrosis factor receptor family, mediates apoptosis. To assess the contribution of Fas to the pathogenesis of retrovirus-induced immunodeficiency, we examined the kinetics of Fas expression on the lymphocytes during the course of murine acquired immunodeficiency syndrome (MAIDS) induced by a defective LP-BM5 murine leukemia virus. The Fas-positive cells were increased in proportion both in alpha beta T cells and B cells with the progression of MAIDS. The appearance of Fas-positive cells in alpha beta T cells preceded those in B cells during the course of MAIDS. Among alpha beta T cells, about half of the Thy1.2+ alpha beta T cells were positive for Fas, while almost all of Thy1.2- CD4+ alpha beta T cells were of the Fas-positive phenotype. The Fas-positive cells in MAIDS mice, especially unique Thy1.2-CD4+ alpha beta T cells, were easily rendered apoptotic by stimulation via Fas, indicating that Fas expressed on the lymphocytes is functional. Furthermore, concomitant infection with Mycobacterium avium in MAIDS mice caused a marked increase in Fas-positive cells accompanied by a severely impaired T cell reactivity to polyclonal stimuli. Taken together, these results suggest that possible participation of the Fas system in the pathogenesis of retrovirus-induced immunodeficiency.

Positive chronotropic and inotropic effects of higenamine and its enhancing action on the aconitine-induced tachyarrhythmia in isolated murine atria

Aconitine and higenamine are the components of aconite root. We investigated the cardiac effects of these compounds on murine right and left atria and the interaction of higenamine with aconitine on the rate of spontaneously beating right atria. Higenamine increased the rate (EC50 = 38 nM) and the force of contraction (EC50 = 97 nM), the maximal responses being comparable with those of isoproterenol. The positive chronotropic effect of higenamine was antagonized by propranolol (30-300 nM) and practolol (10 nM-3 microM), but not by butoxamine (1 microM), indicating that it was a beta 1-adrenoceptor-mediated action. The positive chronotropic effect of higenamine was not changed by pretreatment with reserpine (4 mg/kg, i.p., 4 hr). Aconitine (0.16-0.25 microM) induced tachyarrhythmia in right atria was attenuated by quinidine (1 microM), atropine (8.6 microM) and AF-DX 116 (8.6 microM), suggesting that aconitine activates sodium channels and muscarinic receptors. Higenamine (2.5 nM) and dobutamine (1 nM) did not cause chronotropic effects by themselves, but enhanced the aconitine-induced tachyarrhythmia. These results indicate that higenamine is a beta 1-adrenoceptor full agonist in murine atria and that the aconitine-induced tachyarrhythmia is augmented by the beta 1-adrenergic action of higenamine.

Apoptosis in normal tissues induced by 5-fluorouracil: comparison between bolus injection and prolonged infusion

The induction of apoptosis in normal tissues was histopathologically examined in rats treated with 5-fluorouracil (5-FU). 5-FU was administered by either bolus intravenous injection or 72-hr prolonged intravenous infusion (PIF). Bolus injection and PIF of 5-FU induced different kinetic profiles of apoptosis in the thymus, spleen and ileum. The bolus injections of 5-FU induced a greater extent of apoptosis in these tissues, compared to PIF 5-FU. These data indicate that the kinetics and extent of apoptosis induced by 5-FU depends on the schedule of the 5-FU administration, and that 5-FU-induced toxicity may be related to 5-FU-induced apoptosis in normal tissues.

[Two cases of polymyositis with cardiac involvement]

Cardiac involvement in polymyositis is more prevalent than previously assumed. A 59-year-old and a 58-year-old man presented with cardiac involvement preceding skeletal muscular lesions, admitted because of increased levels of muscle-derived enzymes and left ventricular dysfunction with ECG abnormalities. Coronary angiography revealed no stenotic lesions. Right ventricular endomyocardial biopsy disclosed myocarditis. Left ventriculography showed local asynergy of cardiac wall motion. After admission the weakness and atrophy of skeletal muscles progressed gradually and high levels of muscle-derived enzymes persisted. Electromyography and skeletal muscle biopsy confirmed the clinical diagnosis of polymyositis. Both patients were diagnosed as having polymyositis with cardiac involvement, and treatment with steroids was started. Symptoms improved significantly, and the CK enzyme level was reduced effectively. The condition of one patient was well controlled, but the other suffered from repeated heart failure due to severe left ventricular dysfunction. The clinical spectrum of polymyositis is wide and variable. Further studies are needed to evaluate the detection, management, and prognosis of the disease as well as the pathogenesis and to prevent progression of cardiac involvement.

[M-typing of Streptococcus pyogenes by latex agglutination using monoclonal antibody. Streptococcal Diseases Study Group]

The Lancefield's serotyping system of Streptococcus pyogenes is based on the M protein. The typing sera used for this system are prepared in rabbits immunized with whole organisms of specific serotypes. To remove cross reactive antibodies, the sera should be extensively absorbed with organisms of selected heterologous serotypes. In this study, the possibility of using monoclonal antibody (MAb) as a type specific reagent was discussed. MAb which specifically reacted to M type 12 protein of S. pyogenes were produced by cell fusion. This specific MAb reacted to hot acid extracted M type 12 protein in ELISA but didn't react in agglutination and precipitation. Latex beads were sensitized with MAb and examined by the coagglutination method. The latex reagent could detect a very small amount of M type 12 protein, so it could be used for M typing of S. pyogenes which produced a small amount of M 12 protein.

[Relation between nuclear DNA content and lymph node metastasis in submucosal early gastric cancer]

To investigate a possible relation between the nuclear DNA content and lymph node metastasis of submucosal early gastric cancer, DNA content was analyzed for 46 patients with lymph node metastasis and 67 patients without nodal metastasis. DNA aneuploidy was found in 20 (43.5%) of 46 patients with lymph node metastasis and in 31 (46.3%) of 67 patients without it. There was no statistical difference in the incidence of aneuploidy between the 2 groups. Among the cases with DNA diploidy, the mean value of S phase fraction was 6.82% in patients with lymph node metastasis and 5.65% in those without metastasis. The mean value of S phase fraction was significantly higher in patients with nodal involvement (p < 0.05). Furthermore, among the cases with DNA aneuploidy, the mean value of G2/M phase fraction was 11.03% in patients with lymph node metastasis and 7.54% in patients without metastasis. The mean value of G2/M phase fraction was significantly higher in patients with nodal involvement (p < 0.05). These findings suggest the significant value of the S and G2/M phase fraction for the prediction of lymph node metastasis in patients with submucosal early gastric cancer.

Influence of H-2 class II antigens on the development of murine AIDS

Inbred strains of mice differ markedly in their relative susceptibility to the development of lymphoproliferation and immunodeficiency, a syndrome termed mouse AIDS (MAIDS), after infection with the LP-BM5 mixture of murine leukemia viruses (MuLV). The etiologic virus in this mixture is replication defective (BM5def) and encodes only a variant gag protein. Genetic determinants of resistance and susceptibility to induction of MAIDS reside both within and outside the MHC. In strains with C57BL background genes, the MHC haplotypes associated with resistance to disease include d and a, whereas haplotypes b, s, and q are associated with sensitivity. Previous studies showed that MHC class I genes (H-2Dd, H-2Ld) mapping in the D end of H-2 and other genes mapping proximal to the D end determine resistance to MAIDS. This paper examines the nature of these non-D end MHC genes using assays of MHC recombinant and transgenic mice. We demonstrate that expression of E alpha d confers significant resistance to MAIDS, even in mice that do not express H-2Dd/H-2Ld. Unexpectedly, we found that E alpha polymorphisms can significantly influence resistance, with H-2b mice bearing E alpha d as a transgene having greater resistance to MAIDS than mice bearing an E alpha k transgene. E alpha d-mediated resistance to MAIDS was associated with decreased levels of the BM5def genome in splenic DNA, suggesting that E alpha genes exert their effect by enhancing antiviral activity.

Influence of H-2 class II antigens on the development of murine AIDS

Inbred strains of mice differ markedly in their relative susceptibility to the development of lymphoproliferation and immunodeficiency, a syndrome termed mouse AIDS (MAIDS), after infection with the LP-BM5 mixture of murine leukemia viruses (MuLV). The etiologic virus in this mixture is replication defective (BM5def) and encodes only a variant gag protein. Genetic determinants of resistance and susceptibility to induction of MAIDS reside both within and outside the MHC. In strains with C57BL background genes, the MHC haplotypes associated with resistance to disease include d and a, whereas haplotypes b, s, and q are associated with sensitivity. Previous studies showed that MHC class I genes (H-2Dd, H-2Ld) mapping in the D end of H-2 and other genes mapping proximal to the D end determine resistance to MAIDS. This paper examines the nature of these non-D end MHC genes using assays of MHC recombinant and transgenic mice. We demonstrate that expression of E alpha d confers significant resistance to MAIDS, even in mice that do not express H-2Dd/H-2Ld. Unexpectedly, we found that E alpha polymorphisms can significantly influence resistance, with H-2b mice bearing E alpha d as a transgene having greater resistance to MAIDS than mice bearing an E alpha k transgene. E alpha d-mediated resistance to MAIDS was associated with decreased levels of the BM5def genome in splenic DNA, suggesting that E alpha genes exert their effect by enhancing antiviral activity.

Therapeutic efficacy of long duration-low temperature whole body hyperthermia when combined with tumor necrosis factor and carboplatin in rats

This study examines the effects of a combined modality regimen of long duration-low temperature whole body hyperthermia (6 h at 40.0 degrees C; LL-WBH), recombinant human tumor necrosis factor-alpha (TNF) and carboplatin (CBDCA) on a transplantable fibrosarcoma as well as normal tissue. We compare LL-WBH with short duration-high temperature whole body hyperthermia (2 h at 41.5 degrees; SH-WBH). LL-WBH alone had no significant effect on tumor growth. Tumor growth delay (TGD) with TNF alone (0.1 days) and that with CBDCA alone (1.3 days) were significantly increased to 2.6 days (P < 0.05) and 2.8 days (P < 0.05), respectively, when combined with LL-WBH. Although TNF+CBDCA produced minimally increased TGD of 1.9 days, the combination of LL-WBH+TNF+CBDCA produced a significantly greater TGD of 5.6 days, compared to the other dual combinations (P < 0.01). There was no difference between TGDs for SH-WBH and LL-WBH in combination with TNF+CBDCA. Trimodality treatment-induced normal tissue toxicities, characterized by body weight loss, diarrhea, foot edema, and myelosuppression, were significantly greater in rats treated with SH-WBH+TNF+CBDCA, compared to LL-WBH+TNF+CBDCA. Histopathological examination also demonstrated that SH-WBH+TNF+CBDCA caused severe damage to the lymphoid tissues, intestinal tract, and peripheral microvasulature. We observed minimal histopathological changes observed in rats treated with LL-WBH+TNF+CBDCA. These data suggest that LL-WBH in combination with TNF and CBDCA has a greater therapeutic efficacy than SH-WBH.

Concentration of live retrovirus with a regenerated cellulose hollow fiber, BMM

A concentrated live retrovirus is required for in vitro experiments. A cuprammonium-regenerated cellulose hollow fiber, termed BMM, originally developed for biohazardous viral removal, was used to concentrate two different retroviruses, an ecotropic murine leukemia virus (MuLV) and human immunodeficiency virus (HIV). The BMM was useful for concentrating live virus suspension 10- to 30-fold from 500-1000 ml of culture supernatant. The ecotropic MuLV concentrated by BMM was demonstrated to be viable and biologically intact by XC plaque-forming assay and reverse transcriptase assay. The concentrated MuLV reached a much higher titer in the spleen in mice than the original one. The virus concentration assessed by p24 antigen for HIV was clearly higher than that of the original culture supernatant of HIV-infected cell lines. Since BMM hollow fibers trapped viruses by the sieving mechanism but not by adsorption, the viral particles were recovered by washing and the total live virus recovery rate was high, about 50%. Furthermore 60 min sufficed to handle 1000 ml of supernatant in the case of a filtration area of 0.03 m2. These results show that the BMM provides us with a rapid, safe and efficient method for concentrating live retroviruses.

General pharmacological profile of the new cognition-enhancing agent nefiracetam

The general pharmacological properties of a novel cognition-enhancing agent, nefiracetam (N-(2,6-dimethylphenyl)-2-(2-oxo-1-pyrrolidinyl)acetamide, DM-9384, CAS 77191-36-7) were investigated, and the following results were obtained. 1. Central nervous system: Nefiracetam showed depressant activities (such as ataxia) on general behavior (mice), and inhibited spontaneous locomotor activity, rota-rod and traction performances (mice) and polysynaptic potential of the spinal reflex (rats), and potentiated pentobarbital anesthesia (mice). The drug inhibited electroshock-induced seizure at relatively low doses, but did not affect chemoshock-induced seizure (mice). Nefiracetam failed to show analgesic activity in the tail pinch test, but inhibited the acetic acid-induced writhing syndrome (mice). An inhibitory pattern in the electroencephalogram was observed (cats). Nefiracetam had little or no effect on body temperature (rats). 2. Respiratory and cardiovascular systems: Nefiracetam induced transient decreases in blood pressure, left ventricular pressure and LV dp/dt max at higher doses (dogs). 3. Autonomic nervous system: Nefiracetam had no influence on pupil size (rabbits). The drug induced no significant effect on the pressor response to norepinephrine or depressor response to acetylcholine, but inhibited the contractile response of the nictitating membrane to preganglionic cervical sympathetic nerve stimulation at the highest dose (dogs). 4. Gastrointestinal system: Nefiracetam inhibited gastrointestinal propulsion (mice), gastric emptying rate and gastric secretion (rats) at higher doses. Nefiracetam produced no apparent damage in the gastric mucosa, and had no effect on bile secretion (rats). 5. Isolated smooth muscle: Nefiracetam had no effect on the resting tonus of isolated ileum, whereas it inhibited the contractile response to acetylcholine, histamine, serotonin, nicotine and BaCl2 at higher concentrations (guinea pigs). Nefiracetam had no effect on the resting tonus or the serotonin-induced contraction of stomach fundus (rats). The drug had no effect on the resting tonus or the norepinephrine-induced contraction of vas deferens, but tended to inhibit the contraction induced by nerve stimulation (guinea pigs). Nefiracetam had little or no effect on the resting tonus or oxytocin-induced contraction of virgin uterus, or on spontaneous contraction of pregnant uterus (rats). Nefiracetam did not affect the resting tonus of trachea, whereas it inhibited isoproterenol-induced relaxation at the highest concentration (guinea pigs). Nefiracetam had no chronotropic effect in isolated atria, but showed a slight negative inotropic effect at the highest concentration (guinea pigs). 6. Miscellaneous: Nefiracetam slightly decreased urinary volume, whereas it did not affect urinary electrolyte excretion (rats).(ABSTRACT TRUNCATED AT 400 WORDS)

[Study on new anti-rust disinfectants. III. Effect of alkyl chain length of N-alkyl-N-(2-hydroxy-3-phenoxy)propyl-N,N-dimethylammonium butyl phosphate on the antibacterial activity]

New anti-rust quaternary ammonium salts such as N-alkyl-N-(2-hydroxy-3-phenoxy)propyl-N,N-dimethylammonium butyl phosphate (5) [alkyl homologues are octyl (5a), decyl (5b), dodecyl (5c), tetradecyl (5d), hexadecyl (5e), and octadecyl (5f)] were synthesized in order to find the relationship between the alkyl length and the antibacterial activities. N-Alkyl-N-(2-hydroxy-3-phenoxy)propyl-N,N-dimethylammonium chloride (6) [alkyl homologues are dodecyl (6c), tetradecyl (6d), hexadecyl (6e)] were used as standard compounds in the quantitative analysis. 5c and 6c showed antibacterial activities and these activities were nearly equal to that of benzalkonium chloride (BAC), but, the activities shown by 5e, 5f and 6e were insufficient. 5c-e, showed excellent anti-rust effects, but 6c-e showed insufficient effects, because the former had a butyl phosphate anion and the latter had a chloride anion as a counter ion. 5a, b were insoluble in water. 5c showed a cloud point at 61.5 degrees C and 5d showed a cloud point at 72.0 degrees C at a 10% concentration in water. This phenomenon is similar to those of non-ionic surfactants. 5e was freely soluble in water.

Effects of prolactins on the chromatophores of the tilapia, Oreochromis niloticus

Using isolated scales and split-fin preparations of the tilapia Oreochromis niloticus, the effects of a pair of prolactins of the tilapia Oreochromis mossambicus (tPRL177 and tPRL188) and of ovine prolactin (oPRL) on chromatophores were studied in vitro. These peptides caused melanosome aggregation and dispersion of xanthosomes, especially in the split preparations. Their relative effectiveness was as follows: tPRL177 > oPRL > tPRL188. Moreover, tPRL177 at 100 nM induced a high level of pigment dispersion in cultured xanthophores and erythrophores, but tPRL188 at the same concentration did not have this effect. We also examined the responses of chromatophores to oPRL in primary cell culture and found that xanthophores and erythrophores respond to the peptide by pigment dispersion in a dose-dependent manner, whereas cultured melanophores showed little aggregation of pigment. In denervated melanophores in the split-fin preparations, tPRL177 failed to induce aggregation of pigment. From these results, it was concluded that prolactin affects brightly pigmented cells of the tilapia directly, but affects melanophores indirectly. Norepinephrine which might leak from varicosities of chromatic nerve fibers by virtue of the action of prolactin molecules may be responsible for melanosome aggregation.

Exocrinopathy resembling Sjögren's syndrome induced by a murine retrovirus

BACKGROUND

Sjögren's syndrome (SS) is characterized by lymphocytic infiltration into, and destruction of exocrine glands, resulting in dryness of the mouth and eyes. The disease is considered to have an autoimmune etiology, however, its etiopathogenesis remains largely unknown. Recently, retrovirus is suggested to participate in the pathogenesis of SS, because SS-like lesions are reported in HIV infection or in human T cell leukemia virus type I infection. Moreover, human intracisternal A-type retroviral particles are reported to be detected in SS patients. During the course of our study on the histopathology of mice infected with a murine retrovirus, we happened to find SS-like exocrinopathy in those mice.

EXPERIMENTAL DESIGN

Four-week-old C57BL/6 (B6) mice were injected intraperitoneally with LP-BM5 murine leukemia virus. This virus is known to induce splenomegaly, lymphadenopathy followed by lymphoid malignancy, and profound immunodeficiency in sensitive strains of mice. From 4 to 16 weeks after the virus inoculation, the infected mice were sacrificed and their submandibular and lacrimal glands were analyzed light and electron microscopically and immunohistochemically. The existence of the virus in the lesion in situ was also analyzed by the same method, and additionally by a polymerase chain reaction method.

RESULTS

Periductal lymphocytic infiltration into the submandibular and lacrimal glands was observed in all the virus-infected mice at 4 weeks after the infection and progressed with time. Extraglandular lymphocytic infiltration was also observed in liver, kidney, lung, and pancreas. Immunohistochemical examination revealed that most infiltrating cells into the glands were composed of CD3+ T cells (CD4-dominant), Mac-1+ cells, and B220+ cells. The virus genome was detected in submandibular glands by immunohistochemistry or by polymerase chain reaction. In addition, retroviral particles were secreted into the lumen of exocrine ducts of submandibular glands.

CONCLUSIONS

This might be an SS animal model that is induced by a certain defined retrovirus. This experimental system might provide us with valuable information for analyzing the mechanisms of how a retrovirus could induce SS.

High expression of NK-1.1 antigen is induced by infection with murine AIDS virus

Spleen cells from mice infected with LP-BM5 MuLV, a causative agent of murine acquired immunodeficiency syndrome (MAIDS), were tested for frequency of NK-1.1+ cells and natural killer (NK) activity. During the first 3 weeks following infection, NK activity was well conserved, but by 9-12 weeks post-infection (p.i.), killer activity was depressed; however, the frequency of NK-1.1+ cells increased within 4 weeks of infection and remained elevated thereafter, even following the decline in functional killing activity. Since the absolute number of NK-1.1+ cells increased after infection, the ability of each NK-1.1+ cell to kill the targets seems drastically impaired. Extraordinary expansion of NK-1.1-positive cells was induced by infection with LP-BM5-defective virus (BM5def), a crucial element for MAIDS induction, but not with a helper non-pathogenic virus. With advance of MAIDS the NK-1.1 antigen (Ag) was preferentially expressed on B220+ and Thy-1+ cells, in contrast to CD4+ and CD8+ cells, and among activated large cells a higher proportion was NK-1.1+ than NK-1.1-. Mice with graft-versus-host disease (GVHD) due to class II major histocompatibility complex (MHC) Ag disparity showed a high frequency of NK-1.1 expression in association with other phenotypic alterations, very similar to those seen in mice with MAIDS. In contrast, B6-lpr/lpr mice developed similar activation of B cells but did not exhibit enhanced expression of the NK-1.1 marker. Thus, enhanced expression of the NK-1.1 Ag might be associated with chronic activation of lymphocytes through a common but not universal pathway.

Haematological toxicity of carboplatin and cisplatin combined with whole body hyperthermia in rats

Acute haematological toxicity induced by cis-diammine-1,1-cyclobutane dicarboxylate platinum (II) (carboplatin) and cis-diamminedichloroplatinum (II) (cisplatin) in combination with whole body hyperthermia (WBH) (2 h at 41.5 degrees C) was examined using a F344 rat model. The thermal enhancement ratios (TERs) of drug-mediated thrombocytopenia, anaemia and leukopenia were determined from the dose-response curves of the nadir values of the peripheral platelet, RBC and WBC counts. Carboplatin produced profound depression of platelet counts which was over three-fold greater than cisplatin (14% vs 51% of the control), while the decrease in WBC and RBC counts induced by carboplatin did not differ significantly from those observed with cisplatin. These carboplatin or cisplatin-mediated haematological toxicities were significantly enhanced by WBH. The depth of decrease in platelet, RBC and WBC counts induced by the maximum tolerated dose (MTD) of carboplatin (30 mg kg-1) combined with WBH was identical to that induced by the MTD of carboplatin (70 mg kg-1) alone. The TERs of carboplatin-mediated thrombocytopenia, anaemia and leukopenia were 2.0, 2.8 and 1.9, respectively. The thermal enhancement of cisplatin mediated haematological toxicity was similar to that of carboplatin, with TERs of 1.8 for thrombocytopenia, 2.4 for anaemia and 1.9 for leukopenia. These data, demonstrating thermal enhancement of cisplatin or carboplatin-mediated haematological toxicity, must be taken into account in the clinical application of the combination therapy of platinum and WBH.

Inhibitory effect of NaN3 on the F0F1 ATPase of submitochondrial particles as related to nucleotide binding

The inhibitory effects of NaN3 on the F0F1 ATPase of beef heart submitochondrial particles were investigated. It was shown that NaN3 inhibited the ATPase activity only in the presence of ATP or ADP and the inhibition proceeded slowly. Analysis of the time-course of the inhibition process lead to a conclusion that an ATP binding site which has an apparent Kd of 14.0 +/- 8.7 microM is responsible for the increase of NaN3 sensitivity. This value agreed well with the low Km of ATP hydrolysis characterized before (Muneyuki, E., and Hirata, H. (1988) FEBS Lett. 234, 455-458) and in the range of so-called bi-site catalysis. The same conclusion was derived as for isolated F1 ATPase. From similar analysis, the Kd of this site for ADP was deduced to be 1.34 +/- 0.45 microM, which also agreed with that reported by Pedersen (Pedersen, P.L. (1975) Biochem. Biophys. Res. Commun. 64, 610-616) and also in the same range as reported for the low Km of ATP synthesis by activated submitochondrial particles. These results suggest that hydrolysis through the low Km mode of ATPase reaction leads the enzyme NaN3 sensitive form and this reaction cycle corresponds to the low Km mode of ATP synthesis.

Mycoplasmas stimulate replication of human immunodeficiency virus type 1 through selective activation of CD4+ T lymphocytes

Because mycoplasma infection has often been observed in individuals infected with human immunodeficiency virus type 1 (HIV-1), we investigated the influence of mycoplasmas on HIV replication in vitro. Replication of HIV-1 assessed by reverse transcriptase activity and the p24 antigen level in peripheral blood mononuclear cells (PBMCs) was enhanced by the stimulation with the cell lysates of human mycoplasmas such as Mycoplasma pneumoniae, M. genitalium, and M. fermentans. The most drastic increase of HIV-1 replication was shown in M. pneumoniae, which induced an approximately 10-fold higher replication level than phytohemagglutinin. Stimulation with the mycoplasmas accompanied the induction of blastotransformation of CD4+ but not CD8+ T lymphocytes in PBMCs and the most predominant alterations were induced by the stimulation with M. pneumoniae among the species examined. Production of IL-2 was significantly increased by stimulation with all three species of Mycoplasma used. These results suggest that mycoplasmas induce vigorous replication of HIV-1 through the activation of CD4-positive T lymphocytes.

[Iron deficient erythropoiesis in the young females--analysis by Percoll discontinuous density gradient]

To observe changes in erythropoiesis in iron deficient subjects, we fractioned red cells by discontinuous density gradient using Percoll. Blood samples were taken from 57 young females of 19-21 years old without abnormal history or abnormal biochemical profiles except anemia or iron deficiency. 6 layers gradient were made and 7 fractions (F1 to F7, from the top to the bottom) were obtained. In the lightness fraction (F3 in nonanemic subjects), reticulocytes were concentrated. From patterns of Hemoglobin A1c concentrations of the fractions, it was inferred that red cells with heavier density were older in ages. In cases with iron deficiency or resulting anemia, low density fraction(s) increased in percentage, with relative decrease in that of higher density fractions, as a result of impairment in hemoglobin production. Subjects in whom the lowest density fraction (F3) was less than 5% were regarded to be normal in terms of erythropoiesis, because the fractional pattern was comparable to that of the normal adult males. Among 57 females examined, 24 (52.6%) showed iron deficient erythropoiesis and 6 (10.5%) were iron deficiency anemia (hemoglobin < 120 g/l). The density gradient fractionation of the red cells was proved to be useful in analyzing abnormal erythropoiesis.

Binding of an SJL T cell clone specific for myelin basic protein to SJL brain microvessel endothelial cells is inhibited by anti-VLA-4 or its ligand, anti-vascular cell adhesion molecule 1 antibody

Adhesion molecules probably are required for the migration of T lymphocytes to inflamed tissues, but the roles of these molecules have yet to be understood in the pathogenesis of inflammatory diseases such as multiple sclerosis. The adhesion of an SJL murine T cell clone specific for myelin basic protein (MBP) to endothelial cells (ECs) from SJL newborn brain microvessels was examined. Sixty percent of the 2 x 10(4) T cell clones stimulated once every 2 weeks with MBP were bound to ECs, whereas less than 5% of the same number of lymphocytes from peripheral lymph nodes were bound. However, binding was not central nervous system (CNS)-specific. Monoclonal antibody to VLA-4 or VCAM-1 partially inhibited the binding of the T cell clone to ECs. Binding of the T cell clone to ECs increased when the latter were incubated with IL-1 or TNF, but was not inhibited by anti-VLA-4 or VCAM-1. We suggest that the VLA-4/VCAM-1 pathway functions in the binding of the T cell clone specific for MBP to brain ECs but that adhesion molecules other than VLA-4/VCAM-1 are involved because anti-VLA-4 and anti-VCAM-1 did not produce complete inhibition.

Cloning and sequencing of a cDNA coding for bovine conglutinin

A 912 bp bovine cDNA fragment encoding bovine conglutinin was amplified by the RT-PCR technique. cDNA clones encoding the bovine conglutinin were isolated from a bovine liver cDNA library using a specific probe obtained from the PCR product. These cDNAs carry an insert of 1113 bp coding for a protein of 371 amino acid residues with a signal peptide of 20 residues. The deduced amino acid sequence of cDNA agrees with that determined by conventional amino acid sequence analysis. Two polyadenylation signal sequences were detected in the DNA sequence downstream of the 3' end of the gene. Southern blot analysis of total bovine genomic DNA indicated that there is only one copy of the gene encoding bovine conglutinin. Northern blot analysis of bovine tissues showed that conglutinin mRNA of about 1.5 kb is expressed in the liver and also slightly in the lung.

[Elevation of serum apo E-rich HDL concentration in a patient with cholestatic liver disease]

A remarkable elevation of serum HDL cholesterol concentration (165mg/dl) was found in a 42-year-old Japanese male with chronic pancreatitis who had been cholestatic for several years. An abnormal slow alpha-migrating lipoprotein, larger in particle size and more enriched with cholesteryl ester and apo E than normal HDL, was found in the patient's plasma. Quantitative determination of apo E-rich HDL revealed a striking increase of this lipoprotein in plasma. After choledocho-jejunostomy, a prompt and remarkable decrease of plasma apo E-rich HDL was observed, indicating a direct contribution of cholestasis to the accumulation of apo E-rich HDL in plasma in this patient.

Synthesis of galactose derivatives that render lectin-induced agglutinating ability to liposomes

Three galactose (Gal) derivatives, Gal beta 1-n-C16H33 (1), Gal beta (1-4)-Glc beta 1-n-C16H33 (2), and Gal beta 1-(CH2CH2O)3-n-C16H33 (3), were synthesized and incorporated into liposomes prepared from egg yolk lecithin. Agglutination of these liposomes with Ricinus communis agglutinin was examined by following the change of turbidity. Liposomes containing 3 were effectively agglutinated in contrast to the cases of 1 and 2, suggesting that the oxyethylene groups act as a favorable spacer to extrude Gal groups into the water. Differential scanning calorimetry showed that 3 was mixed with egg yolk lecithin at room temperature, but 1 and 2 were in the gel state, resulting in the phase separation that makes the recognition of Gal residue with Ricinus communis agglutinin difficult.