Propylene Polymerization Behavior of Fluorinated Bis(phenoxy‐imine) Ti Complexes with an MgCl2‐Based Compound (MgCl2‐Supported Ti‐Based Catalysts)

Summary: Fluorinated bis(phenoxy‐imine)Ti complexes 1 – 3 combined with MgCl₂/i‐Bu_nAl(OR)_3−n (MgCl₂‐supported catalysts) were able to polymerize propylene in a living fashion at room temperature to provide slightly to highly syndiotactic poly(propylenes) (PPs) with extremely narrow distributions of molecular weight. These represent the first examples of MAO‐ and borate‐free group 4 metal‐based living catalysts. The supported complexes 2 and 3 formed PPs with higher syndiotacticity and T_m's than the corresponding homogeneous MAO‐activation systems (e.g., 3 : rr 97%, T_m 155 °C; MAO activation: rr 93%, T_m 152 °C). The measured T_m of 155 °C represents the highest known T_m for syndiotactic PPs synthesized at room temperature.

Polymerization of propylene to poly(propylene) with supported Ti‐based catalysts.     

IgG heavy chain allotypes (Gm) in autoimmune diseases.

Serum samples from 100 patients with myasthenia gravis, 322 with Graves' disease, 113 with Hashimoto's disease, 132 with systemic lupus erythematosus (SLE), 192 with insulin-dependent juvenile diabetes mellitus, 83 with Behçet's syndrome, 73 with psoriasis vulgaris, 258 with leprosy, 112 with Duchenne progressive muscular dystrophy and 343 non-related normal controls were studied for Gm allotypes. The incidence of Gm phenotypes with Gm(2) was significantly increased in patients with myasthenia gravis. Graves' disease, Hashimoto's disease, and high in SLE patients. The Gm1,2,21 haplotype was increased in patients with myasthenia gravis (chi 2 = 34 . 08, corrected P less than 0 . 001), Hashimoto's disease (chi 2 = 12 . 39, corrected P less than 0 . 05), Graves' disease (chi 2 = 8 . 65, corrected P less than 0 . 05), and SLE (chi 2 = 6 . 41, 0 . 1 greater than corrected P greater than 0 . 05). The total chi-square for the four different Gm haplotypes was significantly increased in patients with myasthenia gravis (chi 2 = 44 . 46, corrected P less than 0 . 001), SLE (chi 2 = 20 . 70, corrected P less than 0 . 005), Hashimoto's disease (chi 2 = 17 . 03, corrected P less than 0 . 025), and Graves' disease (chi 2 = 11 . 87, corrected P less than 0 . 025). Our data suggest the presence of Gm-associated pathogenic polygenes in certain autoimmune disorders.     

C-reactive protein levels in the serum of asthmatic patients.

BACKGROUND: Asthma is a chronic airway inflammatory disease caused by immune cells such as T lymphocytes and eosinophils. Recently, highly sensitive C-reactive protein (hs-CRP) assays have become available for detecting small changes in CRP levels within the reference range, allowing for the evaluation of clinical inflammation. OBJECTIVE: To investigate the relationship between hs-CRP levels and bronchial asthma. METHODS: We collected blood samples from 109 patients with bronchial asthma, with or without attacks, and measured serum eosinophil cationic protein levels, pulmonary function, and serum CRP levels using an hs-CRP assay. RESULTS: Mean serum hs-CRP levels were significantly higher in patients without attacks (0.473 mg/L) and with attacks (0.908 mg/L) (P < .001 for both) than in controls (0.262 mg/L). Serum hs-CRP levels were inversely correlated with forced expiratory volume in 1 second/forced vital capacity in asthmatic patients (r = -0.4915; P < .01). CONCLUSION: Serum hs-CRP levels may be related to the state of asthma exacerbation and allergic inflammation.     

ATP suppresses the K(+) current responses to FSH and adenosine in the follicular cells of Xenopus oocyte

The application of either follicle-stimulating hormone (FSH) or adenosine (Ade) induces a K(+)-current response in the follicular cells surrounding a Xenopus oocyte under a voltage clamp. These K(+)-current responses are reported to be produced by an increase in intracellular cAMP. A previous application of ATP to the same cells markedly depressed the K(+)-current responses to FSH and Ade. Furthermore, a 2 min application of phorbol 12,13-dibutyrate (PDBu), an activator of protein kinase C (PKC), significantly depressed the K(+)-current responses to FSH and Ade, but it had no significant effect on the Cl(-)-current response to ATP. An application of either ATP or PDBu also depressed the K(+)-current response induced by intracellularly applied cAMP. In contrast to the effect of PDBu, the application of 1-octanol, an inhibitor of gap junction channel, significantly depressed both the Ade- and ATP-induced responses, indicating that the acting site of 1-octanol is different from that of PKC. The results suggest that the depressing effect of ATP on the FSH- and Ade-induced K(+)-current responses might be mediated by PKC activation and that the site of PKC action might be downstream of the cAMP production involved in the K(+) channel opening.     

Oligopeptidases of brush border membranes of rat small intestinal mucosal cells

1. The properties of peptidases located in the brush borders of rat small intestinal mucosal cells have been investigated using a new method for the assay of peptidase activity. In this method amino acids produced by hydrolysis of peptides are oxidized by ophidian L-amino acid oxidase and the hydrogen peroxide produced during reoxidation of the reduced enzyme is estimated spectrophotometrically.2. 10-20% of the total cellular peptidase activity and 50% of the leucylnaphthylamidase (LNAase) activity were found to be tightly bound to the brush borders and to possess different substrate specificity from the supernatant peptidase activity.3. Evidence from kinetic and competition studies indicates the presence of more than one peptidase in the brush borders. The peptidases exhibit pH optima of 8.0-8.5, are inhibited by EDTA, but are not usually activated by divalent metal ions. The brush border peptidases hydrolyse di- and tripeptides, some oligopeptides, leucinamide and leucyl-beta-naphthylamine. On the basis of the Michaelis constants, these substrates differ in their affinities for the enzymes.4. It is proposed that the brush border peptidases serve an analogous function in the terminal stages of protein digestion to that of the disaccharidases in the case of carbohydrate digestion and absorption.     

Microtitration plate enzyme immunoassay to detect PCR-amplified DNA from Candida species in blood.

We developed a microtitration plate enzyme immunoassay to detect PCR-amplified DNA from Candida species. Nucleotide sequences derived from the internal transcribed spacer (ITS) region of fungal rDNA were used to develop species-specific oligonucleotide probes for Candida albicans, C. tropicalis, C. parapsilosis, and C. krusei. No cross-hybridization was detected with any other fungal, bacterial, or human DNAs tested. In contrast, a C. (Torulopsis) glabrata probe cross-reacted with Saccharomyces cerevisiae DNA but with no other DNAs tested. Genomic DNA purified from C. albicans blastoconidia suspended in blood was amplified by PCR with fungus-specific universal primers ITS3 and ITS4. With the C. albicans-specific probe labeled with digoxigenin, a biotinylated capture probe, and streptavidin-coated microtitration plates, amplified DNA from a few as two C. albicans cells per 0.2 ml of blood could be detected by enzyme immunoassay.     

Presumed inhibitory neurons in the macaque inferior temporal cortex: visual response properties and functional interactions with adjacent neurons

Neurons in area TE of the monkey inferior temporal cortex respond selectively to images of particular objects or their characteristic visual features. The mechanism of generation of the stimulus selectivity, however, is largely unknown. This study addresses the role of inhibitory TE neurons in this process by examining their visual response properties and interactions with adjacent target neurons. We applied cross-correlation analysis to spike trains simultaneously recorded from pairs of adjacent neurons in anesthetized macaques. Neurons whose activity preceded a decrease in activity from their partner were presumed to be inhibitory neurons. Excitatory neurons were also identified as the source neuron of excitatory linkage as evidenced by a sharp peak displaced from the 0-ms bin in cross-correlograms. Most inhibitory neurons responded to a variety of visual stimuli in our stimulus set, which consisted of several dozen geometrical figures and photographs of objects, with a clear stimulus preference. On average, 10% of the stimuli increased firing rates of the inhibitory neurons. Both excitatory and inhibitory neurons exhibited a similar degree of stimulus selectivity. Although inhibitory neurons occasionally shared the most preferred stimuli with their target neurons, overall stimulus preferences were less similar between adjacent neurons with inhibitory linkages than adjacent neurons with common inputs and/or excitatory linkages. These results suggest that inhibitory neurons in area TE are activated selectively and exert stimulus-specific inhibition on adjacent neurons, contributing to shaping of stimulus selectivity of TE neurons.     

Construction of radiation-reduced hybrids and their use in mapping of microclones from chromosome 10p11.2-q11.2

Summary Radiation-reduced hybrids for mapping of DNA markers in the pericentromeric region of chromosome 10 were developed. A Chinese hamster/human somatic cell hybrid (762-8A) carrying chromosomes 10 and Y as the only human material were exposed to 40,000 rads of irradiation and then rescued by fusion with non-irradiated recipient Chinese hamster cells (GM459). Southern hybridization analyses revealed that 10 of 128 HAT-resistant clones contained human chromosomal fragments corresponding to at least one marker locus betweenFNRB (10p-11.2) andRBP3 (10q11.2). These hybrids were then used to map microdissection clones previously isolated and roughly mapped to this chromosomal region by fluorescencein situ hybridization (FISH). Two of the six microclones studied could be mapped to the proximity of the D10-S102 locus. These radiation hybrids are useful for the construction of refined genetic maps of the pericentromeric region of chromosome 10.     

Distribution of cocaine recognition sites in rat brain: In vitro and ex vivo autoradiography with [I]RTI-55

The distribution of binding sites of [¹²⁵I]RTI-55 (3β-(4-iodophenyl)tropan-2β-carboxylic acid methyl ester), a phenyl tropane analog of cocaine, and the selective labelling of the dopamine transporter (DAT) were studied by in vitro and ex vivo autoradiography in the rat whole brain. Recent evidence has shown that RTI-55 binds to not only DAT but also serotonin transporter (5HTT). In the present study, in vitro autoradiography revealed that [¹²⁵I]RTI-55 bound to the olfactory tubercle, the caudate putamen, the accumbens nucleus, the midline and lateral geniculate nuclei of the thalamus, the hypothalamic nuclei, the substantia nigra compact part, the subthalamic nucleus, the ventral tegmental area, the superior colliculus, the dorsal raphe nucleus, and the facial nucleus. Further, in the presence of clomipramine, a selective ligand for 5HTT, [¹²⁵I]RTI-55 binding was remarkably inhibited in the midline and lateral geniculate nuclei of the thalamus, the hypothalamic nuclei, the superior colliculus, the dorsal raphe nucleus, and the facial nucleus, while [¹²⁵I]RTI-55 binding remained in the olfactory tubercle, the caudate putamen, the accumbens nucleus, the substantia nigra compact part, the subthalamic nucleus, and the ventral tegmental area. These findings suggest that [¹²⁵I]RTI-55 binds to 5HTT in the former areas and to DAT in the latter areas. It is therefore concluded that RTI-55 is a suitable ligand for studying the action of cocaine in whole brain regions, including the thalamus, the hypothalamus and the dorsal raphe nucleus, regions in which cocaine is thought to act evoking several neurological effects, e.g., analgesia and elevation of adrenocorticotropic hormone. DAT was also labelled selectively both in vitro and in vivo using [¹²⁵I]RTI-55 combined with clomipramine. Therefore, radiolabelled RTI-55, combined with unlabelled clomipramine, which displaces its binding to 5HTT, also appears to be suitable for the selective imaging of DAT in vivo.     

Prevalence of Lyme borreliosis spirochetes in ixodid ticks of Japan, with special reference to a new potential vector, Ixodes ovatus (Acari: Ixodidae).

To determine the vectors of Lyme borreliosis in Japan, the ixodid ticks taken in Hokkaido, Fukushima, Nagano, Ehime, and Kochi Prefectures were examined individually for spirochetal infections by culturing their midgut tissues in BSK medium. The cultivable spirochetes identified as Borrelia burgdorferi were detected in Ixodes persulcatus Schulze adults (15.5% of 634), nymph (6.7% of 15) and Ixodes ovatus Neumann adult (9.6% of 188) from Hokkaido, I. ovatus adults (25.5% of 47) from Fukushima, and I. persulcatus adults (21.7% of 143) and I. ovatus adults (27.1% of 85) from Nagano. However, 72 Haemaphysalis spp. from Ehime and Kochi were free from spirochetal infection. I. persulcatus is a vector of Lyme borreliosis in the Far East, but in Japan, I. ovatus may also transmit the spirochetes to human and feral animals.