Affinity purification of macrophage migration inhibitory factor/glycosylation inhibiting factor (MIF/GIF) from bovine brain by using a peptide ligand derived from a novel serpin

We purified macrophage migration inhibitory factor/glycosylation inhibiting factor (MIF/GIF) from bovine brain by using an affinity column with the C-terminal region peptide of a novel serpin as a ligand. The affinity purified preparation showing a single band on SDS-PAGE contained four peptides on RP-HPLC, which were converged into two peptides time-dependently. Sequence analysis and Western blotting revealed that one was identical to bovine MIF/GIF and the other was an N-terminally modified form of MIF/GIF. These results indicated that there exist at least two forms of MIF/GIF in the bovine brain and that they have an affinity for the C-terminal portion of the serpin.

Limulus kexin: a new type of Kex2-like endoprotease specifically expressed in hemocytes of the horseshoe crab

A Kex2-like protease was identified in hemocytes of the horseshoe crab (Tachypleus tridentatus), named limulus kexin, and a full-length cDNA was obtained from a hemocyte cDNA library. The deduced amino acid sequence contains 752 residues, composed of five domains with a signal sequence, a propeptide, a catalytic domain, a Ser/Thr-rich domain, and a transmembrane domain. The domain organization is very similar to that of the yeast Kex2 except that limulus kexin does not have a cytoplasmic tail. The catalytic domain exhibits striking sequence identities with those of furins, especially Drosophila furin1 (79%). Northern blotting showed specific expression of limulus kexin in hemocytes, suggesting the involvement in proteolytic processing of the granule components of hemocytes.

Improved retrograde axonal transport and subsequent visualization of tetramethylrhodamine (TMR) -dextran amine by means of an acidic injection vehicle and antibodies against TMR

We studied the ability of various dextran amines (DA) to retrogradely label cortical neurons to the full extent of their dendritic configurations. Corticothalamic neurons were labeled by pressure injection of DA into the ventrobasal thalamic nuclei of the rat brain. Of fluorescein-, Texas Red-, Cascade Blue- and tetramethylrhodamine (TMR)-DAs of MW 3000 and TMR-DA of MW 10,000, neurons were most efficiently labeled with TMR-DA of MW 3000. The use of acidic vehicles (pH 1-3) for dissolving TMR-DA enhanced the retrograde labeling, as compared with that of a neutral vehicle. The retrograde labeling with TMR-DA was more clearly demonstrated by using anti-TMR antibodies; the indirect immunofluorescence method with a rhodamine-conjugated secondary antibody and immunoperoxidase method with a peroxidase anti-peroxidase (PAP) complex revealed that the dendrites of many corticothalamic neurons were filled with TMR-DA. The Golgi-like retrograde labeling of TMR-DA visualized by the PAP immunoperoxidase method was comparable with that of biotinylated DA by the avidin-biotinylated peroxidase complex method. Similar Golgi-like dendritic staining was observed among corticospinal neurons after injection of TMR-DA into the corticospinal tract of the spinal cord. Most apical dendrites of corticospinal neurons extended into layer I, whereas those of corticothalamic neurons ended in layer IV or the deep part of layer III. The TMR-DA injection under acidic conditions and immunostaining with the anti-TMR antibodies are considered to be a useful method to visualize the dendrite configuration of cortical projection neurons.

Potent mutagenic potential of 4-methylquinoline: metabolic and mechanistic considerations

4-Methylquinoline (4-MeQ) showed an extraordinarily potent mutagenicity when compared to quinoline and isomeric methylquinolines. The major metabolite of 4-MeQ was 4-hydroxymethylquinoline, which was not mutagenic under the assay condition employed. Deuteration of the methyl group of 4-MeQ resulted in a decrease in the amount of the hydroxymethyl metabolite and an increase in mutagenicity, indicating that hydroxylation of the substituent methyl group is a detoxication process. A 3-chloro derivative of 4-MeQ was proven to be non-mutagenic. 4-Ethyl-quinoline, as well as 4-hydroxymethylquinoline, was much less mutagenic than 4-MeQ. Taking account of the structure-mutagenicity relationship, a possible mechanism is proposed for the potent mutagenic potential of 4-MeQ.

Mercury concentrations in hair from populations in Wau-Bulolo area, Papua New Guinea

Total mercury (Hg) concentrations were determined in scalp hair from the populations in the Wau-Bulolo area, eastern Papua New Guinea (PNG), where humans are exposed to large quantities of Hg through gold-mining activities by Hg amalgamation processes. Humans living upstream and not engaged in gold mining had a mean hair Hg concentration of 0.55 micro g g-1 (range: 0.19-1.1 micro g g-1 (n = 80), which was recognized as the background level in this area. In contrast, the populations involved in gold-mining activities had a significantly higher level of hair Hg (mean: 1.2 micro g g-1, range: 0.39-3.0 micro g g-1 (n = 86) than the background level, indicating direct or indirect exposure to Hg from gold mining. The hair Hg level in populations downstream of the gold-mining area was significantly higher than the background level, due to the consumption of Hg-contaminated fish. Mercury concentrations were significantly higher in males than in females, regardless of location properties.

Effects of rat hepatocytes on macromolecular permeability of bovine aortic endothelial cell monolayer

The aim of this study was to examine whether the hyperpermeable structure of the liver endothelium in vivo is related to the interactions of hepatocytes in a culture system. The permeation of macromolecular FITC-labeled dextran (molecular weight 70,000) through a monolayer of bovine aortic endothelial cells (BAEC), cocultured with rat parenchymal hepatocytes (P-hep), was increased. When the BAEC were cocultured with nonparenchymal hepatocytes (N-hep), the permeability of the BAEC monolayer was not increased. However, when the BAEC were cocultured with a mixture of P-hep and N-hep (PN-hep), the BAEC monolayer was more permeable than when BAEC were cocultured with P-hep alone. The conditioned medium of P-hep did not alter the BAEC monolayer permeability, nor did the extracellular matrix of P-hep alter BAEC permeability. When the BAEC were cocultured with PN-hep, the F-actin content was not altered. These findings suggest that the interaction between hepatocytes and endothelial cells exerts an important effect on the hyperpermeable structure of the liver vessels in vivo.

Identification of a promoter region in the rat prion protein gene

We have demonstrated the presence of a rat prion protein (RaPrP) gene promoter upstream of multiple initiation sites. A 0.1-kb fragment upstream of the 5'-untranslated region contains specific DNA motifs characteristic of promoter elements including an AP-1 binding site, an inverted CCAAT motif and three inverted Sp-1 binding sites. This fragment directs transcription of a luciferase reporter gene in pheochromocytoma cells (PC12) and rat glioma cells (C6), suggesting that it contains the promoter for the RaPrP gene. To more precisely localize the transcription regulatory elements in this region, a series of 5'-deletion mutants were generated. Deletion analysis showed that an inverted CCAAt and adjoining Sp-1 binding sequences may play an important role in transcription of the RaPrP gene.

Three-exon structure of the gene encoding the rat prion protein and its expression in tissues

The prion protein (PrP), encoded by a chromosomal gene, is associated with development of the neurodegeneration of prion-induced diseases. Since determination of the complete structure of the gene encoding PrP is important for understanding gene expression in the central nervous system (CNS), the nucleotide (nt) sequence of the isolated whole gene encoding rat PrP (raPrP) was determined. The rat PrP gene (raPrP) spans 16 kilobases (kb) of the rat genome and contains three exons of 19-47 base pairs (bp), 98 bp, and 2 kb separated by two introns of 2.2 kb and 11 kb. The first and second exons are noncoding, while the third exon contains a short 5' untranslated region, the entire 762-bp open reading frame (ORF), and a 3' untranslated region. The putative raPrP promoter in the 5' flanking region contains putative Sp1, AP-1, and AP-2 binding sites without a consensus TATA box. This TATA box-deficient feature, coupled with the presence of a high G+C content and Sp1-binding sites in the raPrP promoter, characterizes it as a housekeeping gene. Analysis of the raPrP cDNA 5'-end showed that raPrP mRNA transcription was initiated at multiple sites. Northern blot analysis showed that the levels of raPrP mRNA varied among rat tissues, with the highest levels found in the brain and placenta. This determination of raPrP nt sequences, including the introns and the 5' and 3' flanking regions, may make it possible to elucidate cis-acting elements that regulate the expression of this gene in different tissues and cell lines.

Metal accumulation in tissues of seabirds from Chaun, northeast Siberia, Russia

Concentrations of four essential elements (Fe, Mn, Zn, and Cu) and two toxic metals (Cd and Hg) were determined in selected tissues of 11 seabird species collected in Chaun, northeast Siberia. In oldsquaw, arctic tern and herring gull, zinc concentrations were correlated with Cd concentrations. Cadmium concentrations in all the species were highest in kidney and Hg in liver. Cd levels in the liver and kidney of herring gulls were higher than those observed from other breeding areas. Similarly, Hg concentrations were also high in the liver of herring gull. High concentrations of Cd and Hg found in some birds from Chaun might have arisen from exposure on migration.

Specific accumulation of mercury and selenium in seabirds

Total mercury (T-Hg), methyl mercury (MeHg) and selenium (Se) concentrations were determined to elucidate the relationship between Hg and Se levels in the liver of 10 seabird species. Highest concentrations of T-Hg (mean 267 microg/g dry wt), MeHg (mean 25.5 microg/g dry wt) and Se (mean 113 microg/g dry wt) were in the liver of black-footed albatross (Diomedea nigripes). An equivalent molar ratio of 1:1 between T-Hg and Se was found in the liver of individuals which contain over 100 microg Hg/g. However, such a relationship was unclear in other individuals which had relatively low Hg levels. This suggests that Se plays a role in Hg detoxification for those individuals with high Hg. In seabird tissues, Hg and Se levels should be a most important factor determining the relationship between Hg and Se, and fluctuation of Hg burden through molting and the species-specific demethylation capacity would also influence their relationships.

Methanol traps the troponin-tropomyosin-actin complex in an "off-state"

We have investigated the effect of methanol at concentrations below 15% (v/v) on acto-heavy meromyosin (HMM)- and tropomyosin (Tm)-troponin (Tn)-acto-heavy meromyosin-ATPase activities. Methanol slightly enhanced ATPase activity of acto-HMM alone. It had no apparent effect on normalized Tm-Tn-acto-HMM-ATPase activity in the absence of Ca2+. In the presence of Ca2+, however, methanol markedly inhibited normalized Tm-Tn-acto-HMM ATPase activity. These results show that methanol affects the troponin-tropomyosin regulation of acto-HMM ATPase: methanol suppresses the Ca(2+)-sensitivity of the regulatory system and traps it in an "off-state."

Purification of a novel serpin-like protein from bovine brain

We purified a novel serine proteinase inhibitor (serpin)-like protein from the bovine brain and named it B-43 from its molecular mass, 43 kDa. A cleaved peptide from B-43 was copurified with the native B-43. Partial amino acid sequencing of the purified B-43 showed that this protein was homologous to glia-derived nexin/protease nexin-1 (GDN/PN-1), plasminogen activator inhibitor 2, leukocyte elastase inhibitor (LEI) and placental thrombin inhibitor (PTI) among the serpins. Although B-43 had a similar amino acid composition to these serpins, the biochemical features of B-43 were different from them. B-43 did not form sodium dodecyl sulfate (SDS)-resistant serpin-proteinase complexes with thrombin, urokinase, pancreatic elastase and plasmin, suggesting that these proteinases were not the targets of B-43. In contrast to GDN/PN-1, B-43 did not have an affinity for heparin. B-43, having different biochemical properties from GDN/PN-1, appears to be an additional serpin expressed in the brain.

A novel serpin-like protein, B-43, exists in both neurons and astrocytes: an immunohistochemical study in the parietal region of the bovine brain

The presence of a novel member of serine proteinase inhibitor, B-43, was immunohistochemically indicated in both neurons and astrocytes in the parietal region of the bovine brain. B-43-like immunoreactivity was detected in pyramidal cells in the cortex and GFAP-positive astroglial cells in the white matter. The processes of B-43 may play a cooperative role with glia-derived nexin/protease nexin-1 and alpha 1-antichymotrypsin in the brain.

Cell cycle kinetics in childhood acute leukemia studied with in vitro bromodeoxyuridine labeling, Ki67-reactivity, and flow cytometry

Cell cycle kinetics of childhood acute leukemia were determined by the in vitro labeling of marrow blast cells with bromodeoxyuridine (BrdUrd) and subsequent flow cytometry of BrdUrd/DNA and Ki67/DNA in 18 patients with acute lymphocytic leukemia (ALL) and eight patients with acute nonlymphocytic leukemia (ANLL). The BrdUrd-labeling index (BrdUrd-LI) and the duration of S phase (Ts) were calculated from the slope of the regression line obtained by plotting the serial labeling indices against the labeling time. The Ts and potential doubling time (DTpot) of marrow leukemia cells varied from 6.1 to 34.3 h (median 14.3 h) and 1.1 to 20.7 days (median, 7.3 days), respectively. The duration of the total cell cycle time (Tc) which was determined by the Ki-67-derived growth fraction (Ki-67-GF) varied from 14.0 to 112.5 h (median 43.2 h). BrdUrd-LI, DTpot, Ki-67-GF and Tc were significantly correlated with the subtypes (early B-ALL, T/B- ALL and ANLL) of the disease. The median values of LI and GF were much lower in ANLL than in ALL. However, the low proliferative activity of ANLL was not accompanied by a prolonged duration of the total cell cycle time. The longest median duration of Tc was noted in early B-ALL (75.2 h) and the median Tc in ANLL (36.7 h) was close to that in T/B-ALL (34 h). Ts appeared to be rather independent of subtypes of the disease. These results show that there are distinct in vitro growth characteristics in relation to the subtypes of childhood acute leukemia.

HTLV-I associated uveitis in central Japan

AIMS/BACKGROUND

Recently HTLV-I has been shown to cause a kind of endogenous uveitis in south west Japan, where HTLV-I infection is highly endemic. To investigate further the association of HTLV-I infection with the incidence of this uveitis, HTLV-I seroprevalence in central Japan, where HTLV-I infection is not endemic, was studied.

METHODS

HTLV-I seroprevalence was investigated in 1579 patients with various ocular diseases and 1251 normal volunteers as a younger control group. Then HTLV-I seroprevalence was compared in each group.

RESULTS

Of 1579 patients with various ocular diseases, 38 (2.41%) were seropositive. There was a statistically significant difference in HTLV-I seroprevalence between the undefined uveitis group and non-uveitic ocular diseases group (p < 0.05, Yates's correction). However, the seroprevalence in younger patients with undefined uveitis did not differ significantly from that in other groups. As regards the incidence of this type of uveitis, six of 12 (50%) seropositive patients, who were born in south west Japan and had lived in this area for 35 years, developed this undefined uveitis whereas only two of 26 (7.69%) seropositive patients in the other areas in Japan developed this uveitis. The difference was statistically significant (p < 0.05, Fisher's exact probability test).

CONCLUSION

These results suggest that the incidence of this type of endogenous uveitis could be greatly influenced by environmental or hereditary factors including HLA.

Effect of minute amounts of [D-Ala2,MePhe4,Gly(ol)5]enkephalin injected into the tuberomammillary nucleus of rats on histamine release from the cerebral cortex

[D-Ala2,MePhe4,Gly(ol)5]enkephalin (DAGO) (10 ng/0.5 microliters saline solution) injected into the tuberomammillary nucleus (TM) of rats in minute amounts decreased the amount of histamine released to approximately 50% of the basal value on measurements taken 20-40 min after administration. This effect of DAGO was inhibited by the simultaneous microinjection of naloxone (320 ng). These results may be explained in two ways. The first is that the stimulation of mu-receptors results in the inhibition of histaminergic cell bodies. The second is that the somatodendritic release of histamine was increased by the stimulation of mu-receptors and as a result of increased histamine concentration in TM, many histaminergic neurons may be inhibited through the stimulation of H3-receptors. Further studies are necessary regarding the influence of mu-agonists on various cellular sites of histaminergic neurons.

[Seroprevalence of HTLV-I in various ocular diseases in central Japan]

Recently human T-cell lymphotropic virus type I (HTLV-I) has been shown to be responsible for a kind of uveitis in southwestern Japan, where HTLV-I infection is highly endemic. To investigate further the association of HTLV-I with various ocular diseases, we studied HTLV-I seroprevalence in 1,350 patients in central Japan, where HTLV-I infection is not endemic. Of 1,350 patients with various ocular diseases, 40 (2.96%) were seropositive for the retrovirus. There was no statistically significant difference in HTLV-I seroprevalence among various ocular diseases. Four of 9 (44.4%) seropositive cases from southwestern Japan developed HTLV-I associated uveitis (HAU), whereas only 2 of 26 (7.7%) seropositive cases from central Japan developed HAU. The difference was statistically significant (p < 0.05). This suggests that the incidence of HAU could be influenced by environmental or hereditary factors. On the other hand, 3 of 7 (42.9%) patients with episcleritis showed HTLV-I infection.

Prevalence of HTLV-I-associated uveitis in the Kanto Plain, Japan

BACKGROUND

Seroprevalence of antibody to human T-lymphotropic virus type I (HTLV-I) is high in the island of Kyushu, Japan. Reports on the etiological analysis of HTLV-I in patients with uveitis primarily document cases in this island. We studied the seroprevalence of HTLV-I at the Department of Ophthalmology in Yokohama City University Hospital and in Odawara Municipal Hospital, which are in the Kanto Plain on the island of Honshu, Japan.

METHODS

The subjects were 741 patients who visited the two hospitals. The presence of serum antibodies against HTLV-I was assessed using the method of particle agglutination.

RESULTS

Of 454 patients with nonuveitic ocular diseases, 9 (1.98%) were seropositive. Of 143 patients with definite diagnosis of uveitis, 1 (0.70%) was seropositive. Of 144 patients with non-specific uveitis (etiology undefined), 8 (5.56%) were seropositive. Thus, the prevalence of serum antibodies to HTLV-I was higher in patients with non-specific uveitis than in patients with specific uveitis or nonuveitic ocular diseases. Common ocular symptoms of 8 HTLV-I-infected patients with non-specific uveitis were compatible with the clinical features of uveitis described as HTLV-I-associated uveitis (HAU).

CONCLUSION

It is important to suspect HAU in patients with uveitis of unknown etiology, even outside known areas of prevalence.

Sandwich enzyme immunoassay for endothelin with monoclonal antibodies and its application

The development of a sensitive enzyme immunoassay for endothelin is described. This assay is based on a sandwich method using two different monoclonal antibodies against endothelin-1. A monoclonal antibody, which reacted to the C-terminal region of endothelin, was selected as an immobilized antibody. The Fab' fragment of another monoclonal antibody, which might recognize the N-terminal rigid region of endothelin, was used as a horseradish peroxidase-labeled detector antibody. The assay measures endothelin-1 and endothelin-2 with a sensitivity of 1 fmol/ml. We have determined that cultured endothelial cells actually produced endothelin in significant amounts in a time-dependent manner. The levels of plasma endothelin extracted with Sep-Pak tC18 light cartridges could also be monitored. A basal endothelin level was about 0.3 fmol/ml of plasma, and a transient increase was observed 4 h after starting blood collection under in vivo experimentation in the rat. This enzyme immunoassay will facilitate the investigation of physiological roles of endothelin.

Ascorbic acid stimulates barrier function of cultured endothelial cell monolayer

The macromolecular permeability of cultured bovine aortic, bovine venous, and human umbilical vein endothelial cell monolayers was decreased significantly in culture medium containing L-ascorbic acid (Asc Acid; 0.01-0.1 mM) and L-ascorbic acid 2-phosphate (Asc 2-P). Dithiothreitol, which shows reducing activity equivalent to that of Asc Acid, did not affect endothelial permeability. Asc Acid induced a sixfold increase in collagen synthesis by the endothelial cells. The coexistence of L-azetidine 2-carboxylic acid, an inhibitor of collagen synthesis, attenuated the effect of Asc 2-P in a dose-dependent manner. Another collagen synthesis inhibitor, ethyl-3,4-dihydroxybenzoate, also inhibited collagen synthesis and increased endothelial permeability. The decrease in permeability of the endothelial monolayer was dependent on a reduction of the permeability coefficient of the endothelial monolayer. These findings indicate that endothelial barrier function is stimulated by Asc Acid via an increase in collagen synthesis.

Purification and characterization of an alkaline amylopullulanase with both alpha-1,4 and alpha-1,6 hydrolytic activity from alkalophilic Bacillus sp. KSM-1378

The novel alkaline amylopullulanase produced by alkalophilic Bacillus sp. KSM-1378 was purified to an electrophoretically homogeneous state from culture medium. The purified enzyme was a glycoprotein with an apparent molecular mass of about 210 kDa and an isoelectric point of pH 4.8. The N-terminal amino acid sequence was Glu-Thr-Gly-Asp-Lys-Arg-Ile-Glu-Phe-Ser-Tyr-Glu-Arg-Pro and showed no homology to the N-terminal regions of other amylopullulanases reported to date. The enzyme was able to attack specifically the alpha-1,6 linkages in pullulan to generate maltotriose as the major end product, as well as the alpha-1,4 linkages in amylose, amylopectin and glycogen to generate various oligosaccharides. The pH and temperature optima for the pullulanase and alpha-amylase activities were pH 9.5 and 50 degrees C and pH 8.5 and 50 degrees C respectively. Both activities were strongly inhibited by well characterized inhibitors, such as diethyl pyrocarbonate and N-bromosuccinimide. The pullulanase activity was specifically inactivated by Hg2+ ions, alpha-cyclodextrin and beta-cyclodextrin while the amylase activity was strongly inhibited by EDTA and EGTA, although inhibition could be reversed by Ca2+ ions. It is suggested that the single alkaline amylopullulanase protein has two different active sites, one for the cleavage of alpha-1,4-linked substrates and one for the cleavage of alpha-1,6-linked substrates.

Segmental arterial mediolysis: a precursor to fibromuscular dysplasia?

We describe five cases of segmental arterial mediolysis (SAM), formerly known as segmental mediolytic arteritis. SAM occurs in epicardial coronary arteries and in the abdominal splanchnic arteries. Patients with abdominal SAM are generally elderly, whereas coronary SAM presents in neonates, children, and young adults. SAM is initiated by mediolysis of the outer media, which can expand to involve the mid- and inner media. Accompanying alterations include fibrinous linear deposits at the medial adventitial junction and replacement of the lysed muscle fibers by fibrin, erythrocytes, and granulation tissue. Transmural mediolysis results in arterial wall gaps frequently complicated by dissecting hematomas and aneurysms. Abdominal hemorrhages stem from these complications. SAM involving abdominal splanchnic arteries clinically presents with abdominal pain and distension, falling hematocrit, and shock. Simultaneous involvement of more than one abdominal artery is frequent, and branches of the celiac axis are most commonly affected. Various disease states that provoke pathologic stimuli for endothelial mediated vasoconstriction occur in the immediate clinical background of patients with SAM. Certain morphologic features of SAM suggest that this arterial lesion is due to vasospasm, which we putatively ascribe to focal endothelial paracrine dysfunction. Organization of uncomplicated SAM lesions could resemble certain types of fibromuscular dysplasia, suggesting that the genesis of such arterial lesions is related to vasospasm.

Effects of heparin, sperm concentration and bull variation on in vitro fertilization of bovine oocytes in a protein-free medium

The present study was conducted to examine the effects of heparin, sperm concentration and bull variation on the fertilization of bovine oocytes in a protein-free medium supplemented with polyvinyl alcohol and subsequent in vitro development of fertilized embryos. The effects in protein-free medium were compared with those in medium supplemented with bovine serum albumin (BSA). In the presence of heparin (1, 10 and 100 microg/ml), nearly all the oocytes were fertilized with and without BSA. In the absence of BSA, polyspermy was lower (4 to 15%) than in its presence (15 to 48%; P < 0.05). An increase in sperm concentration from 1 x 10(4) cells/ml during insemination enhanced fertilization rate up to 1 x 10(6) cells/ml with and without BSA (14 to 90% and 3 to 77%, respectively). In the absence of BSA, the highest concentration of spermatozoa (1 x 10(7) cells/ml) gave a lower fertilization rate (55%) than that at 1 x 10(6) cells/ml (77%; P < 0.05). Polyspermy neither increased nor decreased sperm concentration without BSA (0 to 8%; P > 0.05). The effects of spermatozoa from 5 different bulls chosen randomly on in vitro fertilization in medium without BSA were examined. Individual bull variation in fertilization rate (36 to 95%) was noted at 3 different heparin concentrations (1, 10 and 100 microg/ml). Polyspermic fertilization was low (0 to 14%) and was the same for all bulls at all heparin concentrations. Embryos fertilized without BSA developed to the blastocyst stage at the same rate (27%) as those with BSA (33%; P > 0.05).