The high-affinity binding of Clostridium botulinum type B neurotoxin to synaptotagmin II associated with gangliosides GT1b/GD1a

125I-labeled botulinum type B neurotoxin was shown to bind specifically to recombinant rat synaptotagmins I and II. Binding required reconstitution of the recombinant proteins with gangliosides GT1b/GD1a. Scatchard plot analyses revealed a single class of binding site with dissociation constants of 0.23 and 2.3 nM for synaptotagmin II and synaptotagmin I, respectively, values very similar to those of the high- (0.4 nM) and low-affinity (4.1 nM) binding sites in synaptosomes. The high-affinity binding of neurotoxin to synaptosomes was specifically inhibited by a monoclonal antibody recognizing with the amino-terminal region of synaptotagmin II. These results suggest that this region of synaptotagmin II participates in the formation of the high-affinity toxin binding site by associating with specific gangliosides.

[Structure and magnetic resonance imaging of the fiber connection between Whitnall's ligament and the superior wall of the orbit]

To confirm the structure of the fiber connection between Whitnall's ligament and the superior wall of the orbit, we observed ten orbits of five Japanese cadavers by magnetic resonance imaging (MRI) and dissection. Our findings were as follows: MRI showed a well-circumscribed low-intensity signal at the fiber connection. Preaponeurotic fat was prominent, and the fibers originating from Whitnall's ligament were fused at the lower face of the capsule of the preaponeurotic fat in four cadavers. The fibers originating from the upper face of the fat were attached to the superior periorbit (minimum width, 15 mm). The fifth cadaver had little preaponeurotic fat and few fibers. These anatomic differences may be within the normal range of variation. We believe that the fibers support Whitnall's ligament and help to retract preaponeurotic fat during levator muscle contraction as the eye opens.

Results of surgery for paralytic exotropia due to oculomotor palsy

In 138 cases of paralytic exotropia due to oculomotor palsy, transposition of the superior oblique muscle and resection of the medial rectus muscle were carried out. Surgery was performed with or without recession of the lateral rectus muscle. The long-term prognosis for 4 years or more was observed in 35 cases. We found that the same results could be obtained by selecting transposition of the superior oblique muscle in cases of complete palsy and resection of the medical rectus muscle in cases of incomplete palsy. There was no benefit in combining resection of the medial rectus muscle when performing the transposition of the superior oblique muscle. Regardless of which method was used, a combination with recession of the lateral rectus muscle greatly improved the effectiveness of the procedure.

Antibodies to recombinant synaptotagmin and calcium channel subtypes in Lambert-Eaton myasthenic syndrome

Several proteins have been postulated as possible targets of immune attack in Lambert-Eaton myasthenic syndrome (LEMS). Heterogeneity of autoantibodies in sera from 20 LEMS patients was studied by comparing their reactivity to synaptotagmin, a synaptic vesicle protein, and voltage-gated calcium channels (VGCCs). Six patients' sera (1 with small cell lung carcinoma (SCLC)) contained antibodies specifically recognizing the recombinant synaptotagmin on immunoblots. Thirteen (11 with SCLC) and 16 (11 with SCLC and 1 with poorly differentiated cell carcinoma in the lung) patients' sera immunoprecipitated omega-conotoxin GVIA-labeled N-type and omega-conotoxin MVIIC-labeled Q-type VGCCs, respectively. Three of 6 synaptotagmin-positive sera had cross-reactivity with N and/or Q subtypes of VGCC; the remaining 3 showed no cross-reactivity with VGCCs. Results indicate that LEMS sera are heterogeneous in the spectrum of containing antibodies, and suggest that this heterogeneity reflects the immune response to various synaptic proteins including not only multiple VGCCs but also synaptosecretory complex proteins.

Identification of Glu173 as the critical amino acid residue for the ADP-ribosyltransferase activity of Clostridium botulinum C3 exoenzyme

Clostridium botulinum C3 exoenzyme specifically ADP-ribosylates rho-p21 in eukaryotic cells. Trp18 and Glu173 of this enzyme were substituted with other amino acids via site-directed mutagenesis. All substitutions at Glu173 caused a significant reduction in affinity for NAD and diminished ADP-ribosyltransferase activity. On the other hand, the activity of enzymes with the substitution at Trp18 remained intact. Swiss 3T3 cells treated with the enzyme with the Trp18 substitution showed the typical morphologic changes of the C3 exoenzyme phenotype. In contrast, no changes were found in cells incubated with the Glu173-substituted enzyme. These results indicate that the Glu173 residue of the C3 exoenzyme plays a key role in interacting with NAD and in expression of ADP-ribosyltransferase activity, which is essential for the phenotypic change by C3 exoenzyme treatment.

Inducible expression of erythroid-specific mouse glycophorin gene is regulated by proximal elements and locus control region-like sequence

Cis-acting elements of the gene for mouse glycophorin, an erythroid-specific membrane glycoprotein, were determined by transient and stable transfection assays using murine erythroleukemia (MEL) cells. Cis-acting elements proximal to the transcription start site of the gene can be separated into the basal promoter (-1 to 191 bp) and the distal element (-133 to -92). The basal promoter contained GGTGG and GATA motifs and the distal element contained GATA-1 and NF-E2 motifs. Deletion analysis of the distal GATA site and its neighboring sequence and DNase-I footprinting/EMSA (electrophoretic mobility shift assay) analysis indicated that induced nuclear factor binding to GATA-1 and its neighboring sequence may be required for expression during MEL cell differentiation induced by dimethyl sulfoxide treatment. The NF-E2 site was also shown to be essential for the promoter activity. An approximately 400 bp far upstream region (-1325 to -948bp) containing the binding motifs for GGGTGG, GATA-1 and NF-E2 showed no enhancing activity when this region was examined by transient transfection assay, but it did show enhancement of the differentiation-specific promoter activity in the stable transfection assay. The far upstream region of mouse glycophorin gene may have a function similar to that of the locus control region (LCR) of human beta-globulin gene cluster.

Inhibition by interleukin-10 of inducible cyclooxygenase expression in lipopolysaccharide-stimulated monocytes: its underlying mechanism in comparison with interleukin-4

Both interleukin-10 (IL-10) and IL-4 inhibited the prostanoid synthesis of lipopolysaccharide (LPS)-stimulated human monocytes, and their inhibition was shown to be based on a common mechanism to suppress the gene expression of inducible cyclooxygenase (COX). COX has been shown to exist in at least two distinct isoforms, designated COX-1 and COX-2, and their gene expressions exhibit different profiles. At both the protein and mRNA levels, the expression of COX-1 was constitutive and was not modulated by treatments with LPS, IL-10, or IL-4. In contrast, the expression of COX-2 was observed only after stimulation with LPS. IL-10 and IL-4 significantly inhibited LPS-induced COX-2 expression. Kinetic studies showed that they inhibited COX-2 mRNA expression within 1 hour after stimulation and that maximal inhibition was consistently observed at 5 hours. Moreover, the addition of cycloheximide (CHX) to LPS-stimulated monocytes resulted in a superinduction of COX-2 mRNA, whereas CHX almost abrogated the abilities of IL-10 and IL-4 to inhibit this gene expression. Experiments with actinomycin D showed that both cytokines accelerated the degradation of COX-2 mRNA. Furthermore, nuclear run-on experiments showed that both cytokines modestly inhibited LPS-induced COX-2 gene transcription. Thus, both cytokines seemed to regulate the COX-related pathway in a similar manner, although their receptor systems did not show any structural similarities. Considering recent findings showing that the drugs that exhibit a selective effect on COX-2 may be more preferable in inflammatory conditions, such biologic activities of IL-10 and IL-4 described above may offer useful tools in controlling inflammatory disorders in the future.

[Botulinum toxin type A (BOTOX) for treatment of blepharospasm: an open label, dose-response study]

The clinical effect of Botulinum Toxin Type A (BOTOX) were studied in patients with blepharospasm. Clinical symptoms were evaluated with Jankovic's rating scale, widely used for blepharospasm. To see dose response, eyelid muscle force of the patients was measured with a device recently developed for measurement of eyelid muscle force. The results showed significant improvement (p = 0.0000) on Jankovic's rating scale in all patient groups after effective dose injections of 0.5, 1.25, and 2.5 U/site. Particularly the number of patients with marked improvement (decrease of six points or more in total score on Jankovic's rating scale) increased with higher dose injections. The eyelid muscle force also decreased by 33.2 +/- 28.1%, 41.7 +/- 25.1%, and 69.6 +/- 5.0% in patients groups after effective dose injections of 0.5, 1.25, and 2.5 U/site, respectively. The decrease of the eyelid muscle force showed significant dose response (p = 0.0254). Mean duration of effect was 12.9 weeks in patients after effective dose injections of 1.25 U/site, which was significantly longer (p = 0.0205) than that of 9.6 weeks in patients after effective dose injections of 0.5 U/site. No severe adverse effects were observed. We concluded that BOTOX injections of 1.25 U/site or more are a safe and effective treatment of blepharospasm.

Bacterial adsorption to fetuin and mucin pellicle

The ability of Actinomyces viscosus (A. viscosus) WVU 627 to attach to hydroxyapatite (HA) beads treated with either bovine fetuin or bovine mucin was studied. All preparations used were blocked with bovine serum albumin prior to incubation with [3H] thymidine-labeled A.viscosus cells. The quantity of fetuin or mucin adsorbed on the HA beads was determined by use of [3H] fetuin or [3H] mucin. Approximately 6 micrograms protein of [3H] fetuin and 20 micrograms of protein of [3H] mucin adsorbed to 5 mg of HA beads at saturation, respectively. The presence of fetuin or mucin on HA beads promoted attachment of the organism. However, HA beads treated with human whole saliva as a positive control promoted A.viscosus attachment more effectively than HA beads treated with these glycoproteins. Attachment of two additional strains (B 236 and B 25) of A. viscosus to HA beads was also promoted by these glycoproteins. The number of A.viscosus cells which attached to fetuin-treated HA beads was dose-dependent, except for strain B 25. For all three A.viscosus strains tested, attachment to the experimental pellicle with mucin was dose-dependent. These findings suggest that the use of these newly developed bacterial adhesion assay systems may be effective for elucidating bacterial adhesion mechanisms.

Non-cushingoid Cushing's syndrome due to adrenocorticotropic hormone-independent bilateral adrenocortical macronodular hyperplasia

This case report describes a 68-year-old man with Cushing's syndrome due to adrenocorticotropic hormone (ACTH)-independent bilateral adrenocortical macronodular hyperplasia (AIMAH). He was referred to our hospital for evaluation of bilateral enlargement of the adrenal glands found incidentally by computed tomography (CT). He had a ten-year history of hypertension. Although he was normokalemic and did not show Cushingoid features, the diagnosis of ACTH-independent Cushing's syndrome was established by endocrinological examinations. His plasma cortisol showed no diurnal rhythm and was unsuppressible by high-dose (8 mg/day) dexamethasone. Plasma ACTH was undetectable and did not respond to corticotropin-releasing hormone. Excised adrenal glands were markedly enlarged (right 28 g and left 64 g). Macroscopic appearance of the glands showed multiple yellowish nodules typical for AIMAH; microscopic findings were also compatible with AIMAH. The present case indicates that patients with AIMAH sometimes do not show typical Cushingoid features and therefore AIMAH can be found incidentally from ultrasound or CT examination of the abdomen.

[Inhibitory effects of interleukin (IL) -10 and viral IL-10 (vIL-10) on the functions of monocytes/macrophages]

In this study, we examined the effects of IL-10 and vIL-10 on the production of superoxide anion (O2-) and nitric oxide (NO) by human monocytes and mouse macrophages. At an optimal concentration, human IL-10 (hIL-10) and vIL-10 significantly inhibited the production of interferon (IFN)-gamma by stimulated human peripheral blood mononuclear cells (PBMNCs). They also efficiently inhibited the production of O2- by both unstimulated and IFN-gamma-activated human monocytes. Mouse IL-10 (mIL-10) also significantly inhibited the production of NO by lipopolysaccharide (LPS) and IFN-gamma-stimulated mouse peritoneal macrophages. Moreover, the production of O2- and NO was effectively suppressed whether the IL-10 was added before or together with the stimulus, indicating that this cytokine acts primarily at an early stage of monocyte/macrophage activation by IFN-gamma and LPS. We also examined the effects of IL-4 and transforming growth factor (TGF)-beta on the production of O2- and NO by human monocytes and mouse macrophages, and found that they significantly inhibited both the production of O2- by human monocytes and the production of NO by mouse macrophages. Moreover, a combination of any two of IL-10, IL-4 and TGF-beta caused an additive effect on the inhibition of O2- production by human monocytes. These results indicated that IL-10 suppresses monocyte/macrophage activation either indirectly via an inhibition of the synthesis of IFN-gamma, a potent monocyte/macrophage activator, by PBMNCs, or directly via the deactivation of monocytes/macrophages. Moreover IL-10 may act in concert with IL-4 and TGF-beta to suppress monocyte/macrophage activation in vivo.

Central giant cell granuloma of the temporal bone

We present two cases of central giant cell granuloma in the temporal bone. CT showed an enhancing tumor causing a smoothly margined temporal squamosa and floor of the middle fossa. External carotid angiograms showed tumor stain mainly supplied by the temporal branches of the internal maxillary artery. In one case, MR images showed a hypointense mass on both T1- and T2-weighted images that was thought to reflect the pathologic character of this lesion.

[Preoperative prediction of the amount of surgical correction by using Botulinum A type toxin for the treatment of paralytic esotropia]

The aim of this study was to obtain the correct choice of initial surgical procedure and to predict the amount of surgical correction by using the maximum reduction rate of eye position after Botulinum A-type toxin injection for the treatment of acquired neurogenic paralytic strabismus. The subjects were 30 with sixth nerve palsy and 33 with non-paralytic esotopia with no previous surgery. The results were that if the maximum reduction rate of eye position after the first injection of 1.25 U was less than 68%, the modified Jensen procedure with recession of medial rectus muscle was necessary to achieve 100% recovery. However, if it was more than 100%, then recession-resection of the horizontal rectus muscles alone produced successful ocular alignment. Based on our data of 100 cases of sixth nerve palsy that showed spontaneous recovery, we conclude that surgical treatment should be planned, if the maximum percentage reduction of preoperative eye position after Botulinum A-type toxin treatment is under 68% (reflecting the inability of the medial rectus muscle to contract and the lengthening of the lateral rectus muscle), and if the patient has no spontaneous improvement at all within 12 weeks after onset.

[Observation of the eyelid structure with opening and closing of the eye in magnetic resonance imaging]

To confirm the changes in the upper eyelid structure during normal movements such as opening and closing we observed the changes with magnetic resonance imaging and obtained the following results. (1) In the anterior lobe of the upper eyelid, the lower part moves more than the upper part. (2) The tarsus slides toward posterior and upper direction when the eye opens. (3) The orbital septum and the orbital fat move posteriorly and thicken when the eye opens. (4) When the eye opens Whitnall's ligament moves posteriorly with a little change of the acting vector direction of the levator muscle. (5) Aponeurosis of the levator muscle clearly separates from Müller's muscle when the eye opens. (6) We suspected that there is some suspending tissue of Whitnall's ligament that consists of a membranous or mesh-like structure in the orbital fat above the levator muscle.

Adaptation of Aspergillus niger to several antifungal agents

Adaptation of Aspergillus niger to short-term stress induced by three antifungal agents [amphotericin B (AMPH), miconazole (MCZ), and ketoconazole (KCZ)] was observed and evaluated quantitatively using individual hyphae. Spores were inoculated onto a poly-L-lysine-coated glass plate making up the base of a culture vessel. Potato dextrose broth (PDB) was added and the vessel incubated for 24 h at 28 degrees C. The growth rate of an arbitrarily selected test hypha was measured automatically. Exposure to AMPH (0.075 micrograms ml-1) stopped the growth of the hypha. After washing with PDB, the same concentration of AMPH was applied again. The growth of the test hypha was not inhibited. This phenomenon was defined as adaptation to the short-term stress of AMPH. Similarly, adaptation was observed with MCZ (0.01 microgram ml-1) and KCZ (0.5 microgram ml-1). The time required for the test hypha to restart growth after washing with PDB depended upon the concentration of MCZ or KCZ, but not upon the concentration of AMPH.

Intradural chordoma: case report and review of the literature

Chordomas are rare neoplasms arising from notochordal remnants found predominantly in the clivus and the sacrococcygeal regions. Most clivus chordomas show extradural extension and bone destruction. Such a tumour can rarely be intradural. This report is concerned with the radiological findings in prepontine intradural chordoma.

Synaptotagmin III is a novel isoform of rat synaptotagmin expressed in endocrine and neuronal cells

Synaptotagmin (p65), an integral membrane protein of synaptic vesicles, is thought to be involved in calcium-dependent exocytosis of synaptic vesicles. Here, we report the cloning and tissue distribution of a novel isoform of synaptotagmin, designated synaptotagmin III. The cDNA clones encoding synaptotagmin III have been isolated from a rat brain cDNA library. Rat synaptotagmin III is a protein of 588 amino acids having 40.5, 38.3, and 64.0% identity with rat synaptotagmin I, rat synaptotagmin II, and o-p65-C, a third synaptotagmin isoform of marine ray Discopyge ommata, respectively. The region of the two internal repeats homologous to the regulatory domain (C2 domain) of protein kinase C is highly conserved among synaptotagmin I, II, and III. RNA blotting studies reveal that synaptotagmin III mRNA is expressed in brain, various endocrine tissues, and hormone-secreting clonal cells. These results suggest that rat synaptotagmin III is a mammalian homolog of o-p65-C and is involved in Ca(2+)-dependent exocytosis of secretory vesicles in endocrine cells, as well as in neurons.

Identification of protein receptor for Clostridium botulinum type B neurotoxin in rat brain synaptosomes

The protein receptor for Clostridium botulinum type B neurotoxin was purified 340-fold from rat synaptosomes by successive chromatography on DEAE-Sepharose, phenyl-Toyopearl, and heparin-Toyopearl columns. 125I-Labeled neurotoxin bound to lipid vesicles containing the protein receptor and ganglioside GT1b or GD1a. The reconstituted receptor showed the same affinities as the native receptor on synaptosomes. Chemical cross-linking of 125I-toxin to the receptor in the presence of gangliosides resulted in formation of a cross-linked product of 161 kDa under reducing conditions. Cross-linking was specific, as it was inhibited by the presence of excess unlabeled toxin. A monoclonal antibody against the purified 58-kDa receptor protein and a monoclonal antibody against the heavy chain (103 kDa) of the neurotoxin reacted with the cross-linked product of 161 kDa in immunoblotting experiments. We determined partial amino acid sequences of the 58-kDa protein, which were identical to synaptotagmin, a synaptic vesicle membrane protein. In addition, the monoclonal antibody against the 58-kDa receptor protein recognized recombinant rat synaptotagmin. These results suggest that synaptotagmin in association with ganglioside GT1b or GD1a may be a natural receptor for C. botulinum type B neurotoxin at the nerve terminals.

A case of 17 alpha-hydroxylase deficiency with retained menstruation

A patient with 17 alpha-hydroxylase deficiency (17OHD) who continued to menstruate is reported. A 24-year-old woman who presented with hypertension, hypokalemia and irregular menses had increased plasma ACTH and mineralocorticoids without any increase in glucocorticoids or sex steroids, and a bilateral adrenal enlargement on abdominal X-ray CT. ACTH stimulation test revealed hyperresponse of the metabolites of the mineralocorticoid pathway and blunted or absent response of those of the glucocorticoid and androgen pathway. Almost all of the abnormalities disappeared after dexamethasone administration. While 17OHD is usually known to accompany hypergonadotropic hypogonadism, the patient continued to menstruate, though irregularly. Although human chorionic gonadotropin administration failed to induce response, basal plasma levels of ovarian steroid (estradiol) and gonadotropins as well as response to LHRH stimulation test were all normal. Thus, the clinical and biochemical features of this case is compatible with the partial deficiency of both adrenals and ovaries, being less severe in the latter. A further analysis especially at molecular level is needed to elucidate the basis for the heterogeneity of this disorder.

IL-10 inhibits prostaglandin E2 production by lipopolysaccharide-stimulated monocytes

Since IL-10 has recently been shown to exhibit pleiotropic effects on human monocytes, it was of interest to determine the effect of this cytokine on prostaglandin E2 (PGE2) production by monocytes. Recombinant IL-10 (rIL-10) did not significantly affect PGE2 production by lipopolysaccharide (LPS)-unstimulated monocytes, but efficiently inhibited PGE2 production by LPS-stimulated monocytes. The inhibition by rIL-10 was achieved in a dose-dependent manner. Recombinant IL-4 also inhibited PGE2 production at the same degree as rIL-10. Viral IL-10 inhibited PGE2 production by monocytes in a similar fashion as did human rIL-10. Endogenously produced IL-10 was also shown to inhibit PGE2 production by LPS-stimulated monocytes. Kinetic studies showed that the inhibition by rIL-10 on PGE2 production was observed at least 3 h after LPS stimulation. Taken together, these results indicate that IL-10 may play an important role in modulating immunological responses via down-regulation of PGE2 production by monocytes.

Immunohistochemical demonstration of embryonic expression of an odor receptor protein and its zonal distribution in the rat olfactory epithelium

Using an antibody raised against an odor receptor protein, we investigated immunohistochemically the spatial distribution in the embryonic and adult rat olfactory epithelium of the olfactory receptor neurons that express the odor receptor protein. In adults, the immunoreactive olfactory receptor neurons were intermingled with immuno-negative receptor neurons, but were mostly restricted within a circumferential zone located in the lateral part of the epithelium. The immunoreactive olfactory receptor neurons were observed as early as embryonic day 14, with a strong tendency to localize in the lateral part of the epithelium. These results indicate that both selection of the odor receptor protein by individual olfactory receptor neurons and zonal segregation of the odor receptor protein expression occur early in embryonic development of the olfactory system.

An ICAM-related neuronal glycoprotein, telencephalin, with brain segment-specific expression

Telencephalin (TLN) is a 130 kd glycoprotein expressed exclusively in neurons of the telencephalon, the most rostral brain segment. In the neurons, TLN is localized to soma-dendritic membrane but not to axonal membrane. In this study, we have cloned cDNA encoding rabbit and mouse TLN. The cDNA-derived primary structure of TLN predicts an integral membrane protein with nine tandem immunoglobulin-like domains in an extra-cellular region, a transmembrane domain, and a short cytoplasmic tail. The distal eight immunoglobulin-like domains of TLN show highest homology with the immunoglobulin-like domains of intracellular adhesion molecules (ICAMs) 1, 2, and 3/R. The structural similarity of TLN with ICAMs provides a new and strong link between immunoglobulin superfamily molecules in the nervous and immune systems. TLN is an example of a dendrite-associated cell adhesion molecule involved in the brain's segmental organization, cell-cell interactions during dendritic development, and maintenance of functional neuronal networks.

ADP-ribosylation of rho p21 inhibits lysophosphatidic acid-induced protein tyrosine phosphorylation and phosphatidylinositol 3-kinase activation in cultured Swiss 3T3 cells

Botulinum C3 exoenzyme was used to specifically ADP-ribosylate and inactivate rho p21, and the effects of rho p21 inactivation on lysophosphatidic acid (LPA)-induced tyrosine phosphorylation were examined in cultured Swiss 3T3 cells. LPA induced a rapid increase in the tyrosine phosphorylation of a number of proteins. Pretreatment of the cells with the C3 exoenzyme caused ADP-ribosylation of rho p21 in the cells and selectively attenuated the phosphorylation of several proteins, including p43 mitogen-activated protein kinase, p125 focal adhesion kinase, and two proteins of 72 and 88 kDa. C3 exoenzyme pretreatment did not block the initial phosphorylation and activation of mitogen-activated protein kinase but suppressed its subsequent rise. In contrast, the enzyme treatment inhibited the induction of phosphorylation of the 72- and 88-kDa proteins and suppressed the basal and LPA-induced tyrosine phosphorylation of p125 focal adhesion kinase. In addition, immunoprecipitation of cell lysates with an antibody directed against the 85-kDa subunit of phosphatidylinositol 3-kinase (PI 3-kinase) co-precipitated a tyrosine-phosphorylated band of 180 kDa. C3 exoenzyme pretreatment suppressed both the phosphorylation of this band and PI 3-kinase activation associated with LPA stimulation. These findings suggest that rho p21 works as a link between the LPA receptor signal and the subsequent tyrosine phosphorylation and PI 3-kinase activation in these cells.