Atypical Epstein-Barr virus infection associated with Gianotti-Crosti syndrome and Bell's palsy.
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Biomedical subjects
Publications and source records attributed to S Maeda.
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AIM: To determine if an antibiotic reduces the incidence of complications associated with influenza-like illness during an influenza epidemic. METHODS: During the outbreak of influenza in Kobe in 1998, 85 patients suffering from an influenza-like illness were randomly assigned to two groups. Patients received placebo or sultamicillin orally for 4 days. The incidence of complications of influenza-like illness were compared and statistically assessed. RESULTS: There was no difference in the duration of fever or the incidence of acute otitis media. However, the incidence of pneumonia was significantly lower in the sultamicillin group than the placebo group (2.4 vs 16.3%, P < 0.05). CONCLUSION: Sultamicillin reduced the incidence of pneumonia associated with influenza-like illness during the influenza epidemic. This result suggests that antibiotics can reduce the rate of pneumonia associated with influenza.
BACKGROUND: An increase in the expression of transforming growth factor-beta 1 (TGF-beta 1) has been proposed to play an important role in the excessive production of extracellular matrix (ECM) proteins seen in diabetes. Because the linkage between glucose metabolism and ECM protein production was found in mesangial cells overexpressed with the brain-type glucose transporter (GLUT1), we hypothesized that TGF-beta 1 could affect glucose metabolism. METHODS: To prove this hypothesis, we examined the effect of TGF-beta 1 on glucose uptake, the first step of glucose metabolism, in mesangial cells. 2-Deoxy-D-glucose (2DOG) uptake and the expression of GLUT1 were measured in mesangial cells exposed to various concentrations of TGF-beta 1. The kinetic constants were determined using 2DOG and 3-O-methyl-D-glucose (3OMG). The effect of anti-TGF-beta neutralizing antibody on 2DOG uptake and GLUT1 mRNA was also examined in mesangial cells cultured under high-glucose (22.2 mM) conditions for 72 hours. RESULTS: TGF-beta 1 stimulated 2DOG uptake in mesangial cells by approximately 2.5-fold in a dose- (1.25 ng/ml maximum) and time-dependent manner, with a peak stimulation at nine hours. The increase in 2DOG uptake by TGF-beta 1 was completely abolished by the addition of 1 microgram/ml cycloheximide, and kinetic analysis of 2DOG or 3OMG uptake revealed an increase in Vmax by TGF-beta 1. Furthermore, TGF-beta 1 enhanced the expression of GLUT1 mRNA from one hour, followed by an enhancement of the expression of GLUT1 protein at nine hours. Finally, 2DOG uptake was significantly enhanced in cells cultured under high-glucose (22.2 mM) conditions as compared with that in cells under normal glucose (5.6 mM) conditions, and this increase in 2DOG uptake in cells under high-glucose conditions was inhibited by the addition of anti-TGF-beta neutralizing antibody. CONCLUSIONS: TGF-beta 1 stimulates glucose uptake by enhancing the expression of GLUT1 in mesangial cells, which leads to the acceleration of intracellular metabolic abnormalities in diabetes.
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c-Src is phosphorylated at specific serine and threonine residues during mitosis in fibroblastic and epithelial cells. These sites are phosphorylated in vitro by the mitotic kinase Cdk1 (p34(cdc2)). In contrast, c-Src in Y79 human retinoblastoma cells, which are of neuronal origin, is phosphorylated at one of the mitotic sites, Ser75, throughout the cell cycle. The identity of the serine kinase that nonmitotically phosphorylates c-Src on Ser75 remains unknown. We now are able to show for the first time that Cdk5 kinase, which has the same consensus sequence as the Cdk1 and Cdk2 kinases, is required for the phosphorylation in asynchronous Y79 cells. The Ser75 phosphorylation was inhibited in a dose-dependent manner by butyrolactone I, a specific inhibitor of Cdk5-type kinases. Three stable subclones that have almost no kinase activity were selected by transfection of an antisense Cdk5-specific activator p35 construct into Y79 cells. The loss of the kinase activity caused an approximately 85% inhibition of the Ser75 phosphorylation. These results present compelling evidence that Cdk5/p35 kinase is responsible for the novel phosphorylation of c-Src at Ser75 in neuronal cells, raising the intriguing possibility that c-Src acts as an effector of Cdk5/p35 kinase during neuronal development.
The expression of cytotoxic granule-associated proteins has been reported in some T-cell or natural killer (NK)-cell lymphomas of mostly extranodal origin, but rarely of nodal origin except for anaplastic large cell lymphoma (ALCL) and Hodgkin's disease (HD). This study analyzed 66 nodal lymphomas expressing T-cell intracellular antigen-1 (TIA-1) and/or granzyme B to characterize the clinicopathologic spectrum of these neoplasms. Four main groups could be delineated. The first group consisted of p80/anaplastic lymphoma kinase (ALK)-positive ALCL (n = 35). The patients were 2 to 62 years of age (median age, 16 years), and the lymphomas pursued a relatively indolent clinical course. The tumors were phenotypically of either T- or null-cell type with constant expression of CD30, epithelial membrane antigen (EMA), and p80/ALK, but not CD15 or BCL2. None harbored Epstein-Barr virus (EBV). The second group consisted of peripheral T/NK-cell lymphoma, the nodal high-grade cytotoxic type (n = 13). The patients were 29 to 72 years in age (median age, 55 years), and the tumors pursued an aggressive clinical course. The tumors often showed pleomorphic, anaplastic, or centroblastoid morphology, and were featured by either EBV association or CD56 expression. The third group consisted of peripheral T-cell lymphoma, of the nodal low-grade cytotoxic type (n = 8). The patients, three men and five women, were 31 to 75 years old (median age, 61 years). Notably, six of them exhibited lymphoepithelioid (Lennert's) lymphoma. The fourth group consisted of cytotoxic Hodgkin's-like ALCL/HD (n = 10), included seven cases of Hodgkin's-like ALCL and three cases of HD, and was characterized by the presence of Reed-Sternberg cells and often the CD15+ phenotype. The patients were all men except for one woman, and they ranged in age from 24 to 84 years (median age, 62 years). The link among these four groups was reinforced by the presence of a highly characteristic large cell with horseshoelike or reniform nuclei-the frequent expression of CD30 and EMA-and the often lack of T-cell receptor-alphabeta. In this series, the expression of p80/ALK and CD56 was also associated with favorable and poor prognoses respectively (p<0.001, log-rank test).
Mutagenesis experiments on the baculovirus Bombyx mori nucleopolyhedrovirus (BmNPV) using 5-bromo-2'-deoxyuridine generated five mutants with a 'few polyhedra' (FP) phenotype. Sequence analysis of the 25K gene homologue of the BmNPV FP mutants revealed nucleotide substitutions in the coding region. Rescue experiments indicated that the FP phenotype of the BmNPV mutants resulted from mutations in the 25K coding region. Effects of infection by these FP mutants were analysed following injection of the viruses into silkworm (B. mori) larvae. Compared to infection with wild-type virus, infection with each FP mutant resulted in reduced host degradation (liquefaction). The degree to which liquefaction was blocked corresponded to the degree of functional disruption of the 25K gene product and to the extent to which polyhedron production was reduced. Electron microscopy revealed that (1) polyhedron production was reduced, (2) very few virions were occluded and those that were lacked envelopes, and (3) the basal lamina of fat-body tissue was not destroyed by infection and accumulations of virions occurred along the membrane. Typical NPV-induced liquefaction was observed following infection with a polyhedrin deletion mutant, indicating that host degradation was not related to polyhedron production. These results suggest that (1) the 25K gene product is involved in the host degradation process caused by virus infection and (2) the FP phenotype is an indirect result of disruption of the 25K gene; activation or suppression of a specific host or viral gene related to tissue degradation and polyhedron formation may be involved.
The genome of the nucleopolyhedrovirus (NPV) (T3 strain) pathogenic for Bombyx mori (Bm) was sequenced and analysed. The BmNPV genome was 128,413 nucleotides long with a G+C content of 40% and contained 136 open reading frames (ORFs) encoding predicted proteins of over 60 amino acids. Although phenotypically different, the genome organizations of BmNPV and Autographa californica multinucleocapsid NPV (AcMNPV) were closely related. The BmNPV genome was over 90% identical to about three-quarters of the genome of AcMNPV. The relatedness of predicted amino acid sequences of corresponding ORFs between BmNPV and AcMNPV was about 90%. However, the BmNPV genome lacked homologues of the following AcMNPV ORFs: Ac3 (conotoxin), Ac7 (orf603), Ac48 (etm), Ac49 (pcna), Ac70 (hcf-1), Ac86 (pnk/pnl) and Ac134 (p94). In addition, BmNPV contained five ORFs related to Ac2. A high frequency of multiple 3 bp insertions was also found within BmNPV and AcMNPV coding sequences.
A bacteriological investigation of Shiga toxin (Stx)-producing Escherichia coli (STEC) O157:H7 was performed on 298 carcasses of cattle at slaughter houses between July 1996 and January 1997 in Gifu Prefecture, Japan. As a result, four Stx-non-producing Escherichia coli O157:H7 strains were isolated from two slaughtered carcasses of cattle. The purpose of this study was to examine the characterization of isolates. Isolates possessed the E. coli attaching and effacing gene (eaeA), and hemolysin gene (hlyA), and harbored 3.0-MDa and 60-MDa plasmids. The Xba I pulsed-field gel electrophoresis (PFGE) pattern showed three similar patterns. Consequently, a closely related genotype of Stx-non-producing E. coli O157:H7 may widely exist in cattle.
We have recently identified a DNA-binding protein (DBP) from the baculovirus Bombyx mori nucleopolyhedrovirus (BmNPV) which can destabilize double-stranded DNA (V. S. Mikhailov, A. L. Mikhailova, M. Iwanaga, S. Gomi, and S. Maeda, J. Virol. 72:3107-3116, 1998). DBP was found to be an early gene product that was not present in budded or occlusion-derived virions. In order to characterize the localization of DBP during viral replication, BmNPV-infected BmN cells were examined by immunostaining and confocal microscopy with DBP antibodies. DBP first appeared as diffuse nuclear staining at 4 to 6 h postinfection (p.i.) and then localized to several specific foci within the nucleus at 6 to 8 h p.i. After the onset of viral DNA replication at around 8 h p.i., these foci began to enlarge and eventually occupied more than half of the nucleus by 14 h p.i. After the termination of viral DNA replication at about 20 h p.i., the DBP-stained regions appeared to break down into approximately 100 small foci within the nucleus. At 8 h p.i., the distribution of DBP as well as that of IE-1 or LEF-3 (two proteins involved in baculovirus DNA replication) overlapped well with that of DNA replication sites labeled with bromodeoxyuridine incorporation. Double-staining experiments with IE-1 and DBP or IE-1 and LEF-3 further confirmed that, between 8 and 14 h p.i., the distribution of IE-1 and LEF-3 overlapped with that of DBP. However, IE-1 localized to the specific foci prior to DBP or LEF-3 at 4 h p.i. In the presence of aphidicolin, an inhibitor of DNA synthesis, immature foci containing IE-1, LEF-3, and DBP were observed by 8 h p.i. However, the subsequent enlargement of these foci was completely suppressed, suggesting that the enlargement depended upon viral DNA replication. At 4 h p.i., the number of IE-1 foci correlated with the multiplicity of infection (MOI) between 0.4 and 10. At higher MOIs (e.g., 50), the number of foci plateaued at around 15. These results suggested that there are about 15 preexisting sites per nucleus which are associated with the initiation of viral DNA replication and assembly of viral DNA replication factories.
The baculovirus Bombyx mori nucleopolyhedrovirus (BmNPV) contains five related open reading frames (ORFs). Recent sequence analyses of several other baculovirus genomes reveal that these ORFs belong to a unique multigene family called the baculovirus repeated ORFs (bro) family. Here we have characterized these five genes from BmNPV at the transcriptional and translational levels. Reverse transcription-PCR and primer extension analyses indicated that transcription of all bro genes occurs by 2 to 4 h postinfection (p.i.) and reaches maximal levels between at 8 and 12 h p.i. Transcription of all genes is initiated between 50 and 70 nucleotides upstream of the start codon, at a characteristic C(T)AGT motif. Expression of a cat reporter gene under the control of each bro promoter provides evidence that a viral factor(s) is required for the transcription of all bro genes. Immunoblot analysis indicated that a population of BRO proteins is produced vigorously between at 8 and 14 h p.i. Immunohistochemical analysis by confocal microscopy showed that BRO proteins are localized in both the nucleus and the cytoplasm at 8 h p.i. Four BmNPV mutants, in which the bro-a, bro-b, bro-c, and bro-e genes were individually inactivated, were successfully isolated. However, exhaustive efforts failed to isolate a bro-d-deficient mutant. Similarly, it was not possible to isolate a double-deletion bro-a bro-c mutant. The bro-d gene may play an irreplaceable functional role(s) during viral infection, while bro-a and bro-c may functionally complement each other.
BACKGROUND: cag pathogenicity island (PAI) is reported to be a major virulence factor of Helicobacter pylori. AIM: To characterise cagA and the cag PAI in Japanese H pylori strains. METHODS: H pylori isolates from Japanese patients were evaluated for CagA by immunoblot, for cagA transcription by northern blot, and for cagA and 13 other cag PAI genes by Southern blot. cagA negative strains from Western countries were also studied. Induction of interleukin-8 secretion from gastric epithelial cells was also investigated. RESULTS: All Japanese strains retained cagA. Fifty nine of 63 (94%) strains had all the cag PAI genes. In the remaining four, cag PAI was partially deleted, lacking cagA transcripts and not producing CagA protein. Details of the PAI of these strains were checked; three lacked cagB to cagQ (cagI) and continuously cagS to cag13 (cagII), and the remaining one lacked cagB to cag8. Western cagA negative strains completely lacked cag PAI including cagA. Nucleotide sequence analysis in one strain in which the cag PAI was partially deleted showed that the partial deletion contained 25 kb of cag PAI and the cagA promoter. Interleukin-8 induction was lower with the cag PAI partial deletion strains than with the intact ones. All Japanese cag PAI deleted strains were derived from patients with non-ulcer dyspepsia, whereas 41 of 59 (70%) CagA-producing strains were from patients with peptic ulcers or gastric cancer (p<0.05). CONCLUSIONS: Most Japanese H pylori strains had the intact cag PAI. However, some lacked most of the cag PAI in spite of the presence of cagA. Thus the presence of the cagA gene is not an invariable marker of cag PAI related virulence in Japanese strains.
The distribution of calcitonin gene-related peptide (CGRP), substance P (SP), vasoactive intestinal polypeptide (VIP) and neuropeptide Y (NPY) was examined in the human temporomandibular articular disk using an indirect immunofluorescent method. All examined neuropeptides were observed in nerve fibers in the disk. These fibers were mostly located in the loose fibrous tissue of the posterior part (posterior attachment) and in the lateral region of the anterior part (anterolateral loose fibrous tissue) of the disk. The posterior attachment and anterolateral loose fibrous tissue occasionally contained isolated nerve fibers which usually showed immunoreactivity (IR) for CGRP or SP. In this tissue, perivascular fibers contained VIP or NPY, whereas isolated fibers and free nerve endings showed the IR for CGRP or SP. These neuropeptides may be involved in the regulation of blood flow and/or pain sensation in the human articular disk of the temporomandibular joint.
The purpose of the present experiment was to study the pathophysiological roles of endothelin-1 (ET-1) in salt-sensitive hypertension with the use of Dahl salt-sensitive (DS) and salt-resistant (DR) rats. PreproET-1 mRNA expression was determined by reverse transcription-polymerase chain reaction. In the kidney, expression of preproET-1 mRNA was greater in DS rats on a normal salt diet compared with DR rats of the same age. In DS rats, the level of preproET-1 mRNA expression in kidney had a significant correlation with systolic blood pressure. The expression of preproET-1 mRNA in aorta and kidney was increased by 3-week high salt intake in DS rats but not in DR rats. Expression of preproET-1 mRNA and ET-1 levels in left ventricle was exaggerated by high salt intake in DS rats. However, there was no significant difference in plasma ET-1 levels between DS and DR rats regardless of salt intake. Pressor response curves for ET-1 in DS rats with or without high salt intake were significantly shifted to the left compared with those in DR rats. A single oral dose (3 to 10 mg/kg) of J-104132 (L-753 037), a potent, orally active mixed endothelin A and B (ET(A)/ET(B)) receptor antagonist, reduced blood pressure to normotensive levels in DS rats with high salt intake, and its action was maintained for >/=24 hours. In DS rats with normal salt intake, J-104132 (10 mg/kg) slightly but significantly decreased blood pressure. DR rats did not show obvious depressor responses to J-104132 (10 mg/kg) regardless of salt intake. These results suggest that ET-1 acts as one of the pathophysiological factors in the development and maintenance of salt-sensitive hypertension, and a mixed ET(A)/ET(B) receptor antagonist could be useful in the treatment for salt-sensitive hypertension.
PTH-related protein (PTHrP) is produced in vascular smooth muscle, where it is postulated to exert vasorelaxant properties by activation of the PTH/PTHrP type 1 receptor. As a model for studying the actions of locally produced PTHrP in vascular smooth muscle in vivo, we developed transgenic mice that overexpress the PTH/PTHrP receptor (PTHrP-R) in smooth muscle. Oocyte injection with a SMP8-PTHrP-R fusion construct yielded six founder mice. F1 offspring were viable and demonstrated selective overexpression of the SMP8-PTHP-R messenger RNA in smooth muscle-rich tissues. Baseline blood pressure measured in conscious mice by tail sphygmomanometry was significantly lower in the receptor-overexpressing mice than that in controls (117 +/- 4 vs. 133 +/- 3 mm Hg; P < 0.05). In anesthetized animals, iv infusion of PTHrP-(1-34)NH2 caused a significantly greater reduction in blood pressure and total peripheral resistance in transgenic mice than in control animals. Vascular contractility was studied in paired, isometrically mounted aortas from 9-week-old transgenic and wild-type mice. The force of contraction in response to phenlyephrine was not significantly different between transgenic and wild-type mice. However, PTHrP-(1-34) NH2 relaxed aortic vessel preparations from transgenic mice to a greater extent than in controls (77.1 +/- 3% vs. 38.4 +/- 4%; P < 0.001). To determine the impact of overexpression of PTH/PTHrP type 1 receptor and its ligand on the development of the cardiovascular system, double transgenic mice were created by crossing SMP8-PTHrP-R transgenic mice with mice overexpressing PTHrP (SMP8-PTHrP). Double transgenic mice died around day E9 with abnormalities in the developing heart. In conclusion, overexpression of PTH/PTHrP type 1 receptor in vascular smooth muscle of transgenic mice reduces blood pressure, probably through sustained activation of the receptor by endogenous ligand. The cardiovascular defects observed in mice overexpressing both PTHrP and its receptor suggest that PTHrP may play a role in the normal development of the cardiovascular system.
PTH-related protein (PTHrP) and its receptor are expressed in vascular smooth muscle cells and are believed to participate in the local regulation of vascular tone. To explore the function of locally produced PTHrP in vascular smooth muscle in vivo, we developed transgenic mice that overexpress PTHrP in smooth muscle using a smooth muscle alpha-actin promoter to direct expression of the transgene. In the PTHrP-overexpressing mice, messenger RNA expression was mainly restricted to smooth muscle-containing tissues. Several founders also expressed the transgene in bone and heart and exhibited striking abnormalities in the development of these tissues. In PTHrP-overexpressing mice, blood pressure was significantly lower than that in wild-type controls (121 +/- 3 vs. 135 +/- 2 mm Hg; P < 0.01). Moreover, the magnitude of the vasorelaxant response to iv infusions of PTHrP-(1-34)NH2 was significantly attenuated in the transgenic animals. A similar desensitization to PTHrP was observed in aortic ring and portal vein preparations. Surprisingly, PTHrP-overexpressing mice were also significantly less responsive to the hypotensive action of infused acetylcholine in vivo and to the relaxant actions of acetylcholine on aortic vessel preparations in vitro. In summary, we have successfully targeted overexpression of PTHrP to the smooth muscle of transgenic mice. When expressed in its normal autocrine/paracrine setting, PTHrP lowers systemic blood pressure and decreases vascular responsiveness to further relaxation by PTHrP and other endothelium-dependent vasorelaxants such as acetylcholine. We postulate that the heterologous desensitization to acetylcholine-induced relaxation in PTHrP-overexpressing blood vessels involves desensitization of second messenger/effector signaling pathways common to PTHrP and acetylcholine.
Stanniocalcin (STC) acts as a regulator of calcium and phosphate homeostasis in an endocrine manner in bony fish. Recently, complementary DNAs encoding human and mouse STC have been characterized, and the messenger RNA (mRNA) expression was identified in various tissues, such as kidney, small intestine, prostate, thyroid, and ovary. Because previous studies concerning the effects of fish STC on mammalian bone have been discussed, there is a good possibility that mammalian STC is a local factor in bone. Here, we demonstrated STC mRNA expression in neonatal mouse calvaria, the primary cultured mouse osteoblast-rich fractions, and human and mouse osteoblastic cell lines. We also mapped the cellular distribution of the STC mRNA in femur and calvaria in developing mice. Several transcripts with a major 4-kb band were detected in all samples. The cellular distribution of the mRNA expression corresponded closely to osteoblasts in both femur and calvaria. Significant labeling of the STC mRNA was also identified in chondrocytes but not in osteoclasts and other bone marrow elements. These results are the first evidence that hormone may be actually expressed in osteoblasts and chondrocytes, and they strongly implicate the involvement of local STC in both endochondral and membrane bone as an autocrine/paracrine factor.
The present study undertook an extensive analysis of the histopathological findings of the atrioventricular conduction system in 14 elderly patients treated with permanent pacemakers for sick sinus syndrome (SSS). Special attention was given to the lowest Wenckebach block points of atrioventricular conduction during rapid atrial pacing, and ventricular rate or duration of ventricular pause during chronic atrial fibrillation. An electrophysiological study (EPS) was conducted under sinus rhythm in 13 patients and under junctional escape rhythm in 1 patient. Three of the 14 cases showed a lower Wenckebach block point of 130 beats/min or less. Two of these 3 cases showed excessive fatty infiltration around the atrionodal junction area and into the atrophic atrioventricular node (AVN) itself. Of the 6 patients who had chronic atrial fibrillation after pacemaker implantation, 2 cases showed a slow ventricular response of less than 60 beats/min and/or a long ventricular pause of 3.3 s. One of the 2 cases showed a lower Wenckebach block point of 130 beats/min at the time of EPS. The other, who later progressed to idiopathic atriomegaly, also showed marked fatty infiltration around the AVN. This fatty lesion was closely associated with diffuse disruption of the muscular fibers connecting the atrophic AVN with the atrium. In addition, most of the remaining cases also had an atrophic AVN. In conclusion, a sparse or absent atrionodal connection and an atrophic AVN due to excessive fatty infiltration in the atrionodal transitional area should be investigated in atrioventricular conduction disturbances in the elderly with SSS.