Alpha-interferon in Kikuchi’s disease

In Japan, histiocytic necrotizing lymphadenitis (Kikuchi’s disease) is a relatively common reactive lesion affecting lymph nodes, but the histogenesis and pathogenesis of the disease have not been clarified. Alpha-interferon has a role in the body’s defense against, viral infections. Using a polyclonal antibody to human alpha-interferon, we found numerous cells, mainly histiocytes, containing alpha-interferon in affected foci in the lymph nodes from 24 patients with Kikuchi’s disease. Tubuloreticular structures, thought by some authors to be associated with the production of interferon, were detected by electron microscopy in histiocytes, activated lymphocytes and vascular endothelial cells in the affected foci. These results suggested that the formation of tubuloreticular structures is a secondary phenomenon following stimulation by alpha-interferon. Further, the activity of 2′–5′ oligoadenylate synthetase, which is induced by alpha-interferon and enhanced during the early or active stage of viral infection, showed increased levels of activity in the active stage of Kikuchi’s disease and decreased to normal levels in the convalescent stage 2 weeks later. These results suggested the possibility of a viral etiology for Kikuchi’s disease.     

Structure of the Bombyx mori fibroin light-chain-encoding gene: upstream sequence elements common to the light and heavy chain.

Two overlapping genomic clones containing the fibroin light-chain (Fib-L)-encoding gene (Fib-L) were obtained from the cosmid library of the silkworm, Bombyx mori J-139, by hybridization with the Fib-L cDNA clone. Sequencing of the 14.6-kb region revealed that Fib-L was 13472 bp long containing seven exons, and that the gene contained a large first intron which occupied about 60% of the gene. Comparison of restriction patterns of the J-139 Fib-L with those of eight other B. mori breeds producing normal-level fibroin demonstrated that considerable restriction-fragment length polymorphisms were present in regions containing the first intron and the 3′-flanking sequence. However, sizes of the Fib-L mRNA and the Fib-L polypeptide were very similar among the nine breeds tested, suggesting that the exon sequences and the splice signals were all well conserved. 5′-Flanking regions of Fib-L and the fibroin heavy-chain (Fib-H)-encoding gene (Fib-H) compared in this study contained three 18-30-bp sequences of high similarity and many 8-10-bp common elements, six of which coincided with the binding sites of homeodomain proteins. Gel retardation assays with the nuclear extracts of the posterior and middle silk glands suggested that protein factors present in the posterior silk-gland nuclei could bind to a set of those common upstream elements.     

The parasitoidOoencyrtus nezarae (Hymenoptera: Encyrtidae) prefers hosts parasitized by conspecifics over unparasitized hosts

Summary Two laboratory experiments were conducted to examine the ovipositional preferences of the egg parasitoidOoencyrtus nezarae Ishii (Hymenoptera: Encyrtidae) for parasitized and unparasitizedMegacopta punctatissimum Montandon (Hemiptera: Plataspidae). Females that had never oviposited or that had not oviposite for 3 days preferred recently parasitized hosts more than unparasitized hosts. The preference for recently parasitized hosts appeared to be mediated by the punctures in already parasitized hosts made by the ovipositor of the first female. Survival of the parasitoid progeny was lower in recently parasitized hosts than in unparasitized hosts. However, handling time of parasitized hosts was extremely short relative to that of unparasitized hosts, because the superparasitizing female could use the punctures made by the previous females. It is concluded that the females preferred the parasitized hosts over unparasitized hosts because the benefit of saving time and energy for drilling was more than the cost of progeny survival.     

Identification and genetic analysis of semidwarfism-related proteins in rice (Oryza sativa L.)

Summary By transferring a semidwarf gene (sd-1) from Taichung Native 1 into a tall Japanese cultivar, Norin 29, through seven backcrosses, a semidwarf near-isogenic line SC-TN1 was obtained. The proteins of the embryo in Norin 29 and SC-TN1 were separated by two-dimensional electrophoresis. Most of the proteins showed the same electrophoretic pattern. However, it was found that there was a difference in the appearance of two basic glycoproteins designated as SRP-1 and SRP-2. These proteins exhibited the same molecular mass, but different isoelectric points. Hybridization results indicated that a single locus controls SRP-1 and SRP-2 with codominant alleles. The gene symbol Srp was given to this locus, with alleles Srp-1 and Srp-2 responsible for SRP-1 and SRP-2, respectively. Srp-2 was found in all of the semidwarf cultivars and lines having sd-1, except a tall cultivar Tsaiyuan-chung. This finding suggests that Srp-2 may be closely linked with sd-1. The amounts of these proteins markedly increased after water absorption of the seed, suggesting that these proteins may be related to the early development of the plant.     

On some freshwater harpacticois from Japan,closely related to Canthocamptus mirabilis Štěrba

Preliminary comparisons are presented, of certain diagnostic characters of four species of Canthocamptus, all the specimens examined here being collected from freshwater bodies throughout Japan. The geographical distribution of each species is also discussed.Contribution No. 69 from the Itako Hydrobiological Station, Ibaraki University.     

Mode of inhibitory action of cholecystokinin in amylase release from isolated rat pancreatic acini--inhibition of secretory process post to protein kinase C-calcium ion systems

The incubation of isolated rat pancreatic acini with low doses (1 x 10(-11)-1 x 10(-10) M) of cholecystokinin-octapeptide (CCK8) induced amylase release. This CCK8-induced amylase release has been shown to be mediated through the protein kinase C activation and the Ca2+ mobilization which are linked to the phospholipase C-mediated hydrolysis of phosphoinositides. However, the incubation of the acini with high doses (1 x 10(-9)-1 x 10(-7) M) of CCK8 reduced amylase release to the level less than that induced by the maximally effective dose (1 x 10(-10) M) of this secretagogue. Under the same conditions, the high doses of this secretagogue did not inhibit the phospholipase C-mediated hydrolysis of phosphoinositides. The stimulatory action of the maximally effective dose of CCK8 in amylase release was mimicked by the simultaneous addition of protein kinase C-activating 12-O-tetradecanoylphorbol-13-acetate (TPA) and Ca2+ ionophore A23187. A high dose (1 x 10(-7) M) of CCK8 reduced the amylase release induced by the combination of TPA and A23187. These results suggest that the high doses of CCK8 inhibit the secretory process post to the protein kinase C-Ca2+ systems and thereby reduce the amylase release induced by the maximally effective dose of CCK8 in rat pancreatic acini.     

Primary structure of non-histone protein HMG1 revealed by the nucleotide sequence

The isolation and sequencing of a cDNA clone coding for the entire sequence of pig thymus non-histone protein HMG1 are described. The sequence analysis reveals a complete 2192-nucleotide sequence with a 5'-terminal untranslated region of 11 nucleotides, 642 nucleotides of an open reading frame that encoded 214 amino acids, and a 3'-terminal untranslated region of 1539 nucleotides. The HMG1 protein, deduced from the nucleotide sequence, has a molecular weight of 24,785 and a C-terminal of a continuous run of 30 acidic amino acids, encoded by a simple repeating sequence of (GAN)30. The predicted amino acid sequence is homologous to HMG1, HMG2, and HMG-T sequences from several sources, suggesting that the protein conformation is under evolutionary constraints. Northern blot analysis reveals that another hybridizable RNA species of smaller size is present. Southern blot analyses suggest that pig genome contains several HMG1 gene equivalents.     

5C6-F4, a novel 100,000-dalton rat lymphocyte activation antigen defined by monoclonal antibody

Con A-activated rat thymocytes were used to immunize mice, and immune spleen cells were fused with NS/1 myeloma cells. One clone, designated 5C6-F4, reacted strongly with Con A-activated rat thymocytes and some LPS-activated rat spleen cells but not with normal thymocytes, spleen cells, or bone marrow cells of rat origin. The 5C6-F4 did not react with Con A-activated thymocytes of mouse origin. Immunoprecipitation of 5C6-F4 antigen from surface-iodinated Con A-activated rat thymocytes or LPS-activated rat spleen cells revealed its m.w. to be approximately 100,000. The kinetic studies of the expression of 5C6-F4 antigen revealed that 5C6-F4 antigen was detectable at 6 hr after Con A stimulation of rat spleen cells, whereas IL 2 receptor (IL 2R) was detectable at 12 hr. The appearance of 5C6-F4 antigen and IL 2R precede the onset of DNA synthesis of Con A-activated spleen cells. Thus, 5C6-F4 antigen is classified as early activation antigen. The 5C6-F4 inhibits the lymphocyte proliferation induced by mitogen and the IL 2-driven rat T cell proliferation. Sequential immunoprecipitation study as well as binding inhibition study indicated that the 5C6-F4 antigen is distinct from IL 2R molecule. The 5C6-F4 antigen appears to be a novel rat lymphocyte activation antigen that exhibits immunoregulatory function and also may serve as a useful marker of T cell activation.     

Generation of cytotoxic T lymphocytes from thymocyte precursors to trinitrophenyl-modified self antigens. II. Establishment of a T cell hybrid clone constitutively producing killer-helper factor(s) (KHF) and functional analysis of released KHF

T cell hybridoma lines were constructed by fusion of Mycobacterium tuberculosis-primed and boosted BALB/c T cells with the AKR-derived T lymphoma cell line BW5147. Certain of the hybridomas prepared in this manner secreted constitutively into their culture supernatants biologically active molecules that displayed precursors of cytotoxic T cell activating properties characteristic of killer-helper factor (KHF). Cell surface analysis revealed that the hybridomas were indeed somatic cell hybrids between the two respective partner cells used for fusion. KHF properties of these hybridoma supernatants were verified by their capacity to stimulate peanut agglutinin-binding (PNA+) C3H/He thymocytes to respond in vitro to 2,4,6-trinitrophenyl(TNP)-modified syngeneic stimulator cells in conjunction with suboptimal doses (10 U/ml) of interleukin 2 (IL 2) for the generation of H-2-restricted, TNP-reactive cytotoxic T cells. The biologically active molecules secreted by a T cell hybrid clone (2Y4) were, like conventional KHF, distinct from IL 1, IL 2, or immune interferon (IFN-gamma). The partially purified KHF derived from 2Y4 cells shows activity at apparent m.w. range of 34,000 to 60,000 on gel permeation, and is relatively homogeneous with respect to isoelectric point, which was approximately 4.5 to 4.7. The partially purified 2Y4-KHF is able to augment proliferation of as well as the expression of IL 2 receptors on PNA+ thymocytes in conjunction with IL 2. Finally, addition of 2Y4-KHF on day 0, followed by the addition of IL 2 on day 2 for 7 days of culture was effective in generating potent CTL responses, whereas addition of IL 2 on day 0, followed by the addition of 2Y4-KHF on day 2 to the culture was ineffective.     

Amidase-like activity of calpain I and calpain II on substance P and its related peptides

Porcine calpains (Ca2+-dependent cysteine proteinases) I and II, which had been purified each to a homogeneous state, were found to hydrolyze specifically carboxyl-terminal amide of substance P and several other biologically active peptidyl amides. This amidase-like activity was demonstrated both by determining released ammonia and by separating products on high-performance liquid chromatography followed by amino acid analysis. The calpain-catalyzed deamidation of substance P occurred exclusively at the carboxyl-terminal amide, leaving the side-chain glutamine intact. Enkepharinamide and MSH-release inhibiting factor were scarcely deamidated. Calpains I and II showed similar specificities for these amide substances and similar profiles of inhibitions by various protease inhibitors, but distinctly different Ca2+ requirements. The specificity constants, kcat/Km, for substance P were found to be three to four orders of magnitude higher than those for the synthetic substrates.