Functional importance of the coiled-coil of the Ebola virus glycoprotein

Ebola virus contains a single glycoprotein (GP) that is responsible for receptor binding and membrane fusion and is proteolytically cleaved into disulfide-linked GP1 and GP2 subunits. The GP2 subunit possesses a coiled-coil motif, which plays an important role in the oligomerization and fusion activity of other viral GPs. To determine the functional significance of the coiled-coil motif of GP2, we examined the effects of peptides corresponding to the coiled-coil motif of GP2 on the infectivity of a mutant vesicular stomatitis virus (lacking the receptor-binding/fusion protein) pseudotyped with the Ebola virus GP. A peptide corresponding to the C-terminal helix reduced the infectivity of the pseudotyped virus. We next introduced alanine substitutions into hydrophobic residues in the coiled-coil motif to identify residues important for GP function. None of the substitutions affected GP oligomerization, but some mutations, two in the N-terminal helix and all in the C-terminal helix, reduced the ability of GP to confer infectivity to the mutant vesicular stomatitis virus without affecting the transport of GP to the cell surface, its incorporation into virions, and the production of virus particles. These results indicate that the coiled-coil motif of GP2 plays an important role in facilitating the entry of Ebola virus into host cells and that peptides corresponding to this region could act as efficient antiviral agents.

Structure of the infected cell protein 0 gene of canine herpesvirus

The canine herpesvirus infected cell protein 0 (CICP0) gene was sequenced. The CICP0 gene was transcribed as a 1.4 kb mRNA from the end of the unique long region nearby the internal repeat during early phase of productive infection of the virus. An open reading frame of the gene encodes a polypeptide of 333 amino acids. The RING finger domain and acidic transcriptional activation domain were found at the N-terminus and within the middle region in the deduced amino acid sequence, respectively, suggesting that the CICP0, like the ICP0 of herpes simplex virus 1, is a transactivating protein.

Up-regulation of monocyte chemoattractant protein-1 in tubulointerstitial lesions of human diabetic nephropathy

BACKGROUND

We previously described that monocyte chemoattractant protein-1 (MCP-1) plays an important role in progressive glomerular and interstitial damage in inflammatory renal diseases. However, the expression of MCP-1 in diabetic nephropathy remains to be investigated.

METHODS

We examined whether locally expressed MCP-1 participates in human diabetic nephropathy via recruiting and activating monocytes/macrophages (Mphi). Urinary and serum MCP-1 levels were measured by enzyme-linked immunosorbent assay in 45 patients with diabetic nephropathy. The presence of MCP-1 in diseased kidneys was determined by immunohistochemical and in situ hybridization analyses.

RESULTS

Urinary MCP-1 levels were significantly elevated in patients with diabetic nephrotic syndrome and advanced tubulointerstitial lesions. Moreover, urinary levels of MCP-1 were well correlated with the number of CD68-positive infiltrating cells in the interstitium. In contrast, serum MCP-1 levels remained similar to those of healthy volunteers. Furthermore, we detected the MCP-1-positive cells in the interstitium of diabetic nephropathy via both immunohistochemical and in situ hybridization analyses.

CONCLUSION

These observations suggest that locally produced MCP-1 may be involved in the development of advanced diabetic nephropathy, especially in the formation of tubulointerstitial lesions possibly through Mphi recruitment and activation. Moreover, up-regulation of MCP-1 may be a common pathway involved in the progressive tubulointerstitial damage in diabetic nephropathy as well as inflammatory renal diseases.

Recognition of N-glycolylneuraminic acid linked to galactose by the alpha2,3 linkage is associated with intestinal replication of influenza A virus in ducks

The hemagglutinin (HA) of H3 human influenza viruses does not support viral replication in duck intestine despite its avian origin. A Leu-to-Gln mutation at position 226 and a Ser-to-Gly mutation at position 228 in the HA of human A/Udorn/307/72 (H3N2) permit a reassortant virus [human Udorn HA, with all other genes from A/mallard/New York/6750/78 (H2N2)] to replicate in ducks. To understand the molecular basis of this change in host range restriction, we investigated the receptor specificity of duck influenza viruses as well as of human-duck virus reassortants. The results indicate that the recognition of a glycoconjugate moiety possessing N-glycolneuramic acid (NeuGc) linked to galactose by the alpha2,3 linkage (NeuGcalpha2,3Gal) is associated with viral replication in duck intestine. Immunofluorescence assays with NeuGcalpha2,3Gal-specific antiserum detected this moiety primarily on the crypt epithelial cells of duck colon. Such recognition, together with biochemical evidence of NeuGc in crypt cells, correlated exactly with the ability of the virus to replicate in duck colon. These results suggest that recognition of the NeuGcalpha2,3-Gal moiety plays an important role in the enterotropism of avian influenza viruses.

Measurement of serum IgA and C3 may predict the diagnosis of patients with IgA nephropathy prior to renal biopsy

The levels of serum IgA and C3 in patients with IgA nephropathy were determined using international standard serum (IFCC/CRM470) in a multicenter trial in Japan. The ratio of serum IgA to C3 (serum IgA/C3 ratio) without any information from renal biopsy was used for the diagnosis of IgA nephropathy. Three hundred and six patients with IgA nephropathy and other glomerular diseases, and 418 healthy adults were examined. The new diagnostic standardized criterion in patients with IgA nephropathy, obtained by nephelometric immune assay based on the international reference preparation CRM470, was 315 mg/dl. The serum IgA/C3 ratio was a more useful marker for distinguishing IgA nephropathy from non-IgA nephropathy together with serum IgA levels. This suggests that the measurement of serum IgA and C3 may predict the diagnosis of patients with IgA nephropathy prior to renal biopsy.

Epitope mapping of the influenza A virus RNA polymerase PA using monoclonal antibodies

To obtain reagents to functionally map the PA protein, we produced monoclonal antibodies specific to this protein. Twenty-two monoclonal antibodies reacting with PA protein in ELISA were divided into 10 groups on the basis of competitive binding patterns to this protein. Of these, seventeen monoclonal antibodies bound to PA polypeptide spanning amino acids 101-400 and three bound to that of amino acids 518-600, while the other two did not react with any PA polypeptides tested with the exception of full-length PA. Among these monoclonal antibodies, only five reacted with PA in A/PR/8/34 virus-infected cells in indirect immunofluorescence assay. Thus, we obtained monoclonal antibodies that recognize at least 10 distinct regions of the PA molecule. These monoclonal antibodies should be useful in dissecting functions of the PA protein.

Precursor genes of future pandemic influenza viruses are perpetuated in ducks nesting in Siberia

Influenza A viruses of different subtypes were isolated from fecal samples of ducks in their nesting areas in Siberia in summer from 1996 to 1998. Phylogenetic analysis of the NP genes of the isolates in Siberia and those in Hokkaido, Japan on their flyway of migration from Siberia to the south in autumn revealed that they belong to the Eurasian lineage of avian influenza viruses. It is noted that the genes of the isolates in Siberia are closely related to those of H5N1 influenza virus strains isolated from chickens and humans in Hong Kong in 1997 as well as to those of isolates from domestic birds in southern China. The results indicate that influenza viruses perpetuated in ducks nesting in Siberia should have contributed genes in the emergence of the H5N1 virus in Hong Kong. Vaccine prepared from avirulent A/duck/Hokkaido/4/96 (H5N3) influenza virus was potent enough to protect mice from challenge with lethal dose of the pathogenic H5N1 virus [19]. Intensive surveillance study of aquatic birds especially in Siberia is, therefore, stressed to provide information on the future pandemic influenza virus strains and for vaccine preparation.

Distinct expression of CCR1 and CCR5 in glomerular and interstitial lesions of human glomerular diseases

We investigated the presence of CCR1- and CCR5-positive cells immunohistochemically in the kidneys of 38 patients with several renal diseases, including 13 crescentic glomerulonephritis patients. In addition, we determined cell phenotypes of CCR1- and CCR5-positive cells using a dual immunostaining technique. Urinary levels of their ligands, for CCR1 and CCR5; macrophage inflammatory protein (MIP)-1alpha, MIP-1beta and regulated upon activation in normal T cells expressed and secreted (RANTES) were evaluated by enzyme-linked immunosorbent assay. CCR1- and CCR5-positive cells were detected in both glomeruli and interstitium of the diseased kidneys. Using a dual immunostaining technique, these positive cells were CD68-positive macrophages (MPhi) and CD3-positive T cells. The number of CCR1-positive cells in glomeruli was correlated with urinary levels of MIP-1alpha. The number of CCR1-positive cells in the interstitium was correlated with both urinary MIP-1alpha and RANTES levels. CCR1-positive cells in the interstitium remained after glucocorticoid therapy, most of which were MPhi, and were correlated with the intensity of interstitial fibrosis and tubular atrophy. Glomerular CCR5-positive cells were well correlated with extracapillary lesions and urinary MIP-1alpha levels, while interstitial CCR5-positive cells, mainly CD3-positive T cells, were correlated with interstitial lesions and urinary RANTES levels. Renal CCR5-positive cells were dramatically decreased during convalescence induced by glucocorticoids. These results suggest that chemokine receptor signaling may be pivotal for human renal diseases through the recruitment and activation of MPhi and T cells; CCR5-positive cells may participate in glomerular lesions including extracapillary lesions via MIP-1alpha and in interstitial lesions via RANTES. CCR1 may be involved in interstitial lesions in resolving phase after glucocorticoid therapy.

Introduction of the interleukin-10 gene into mice inhibited bleomycin-induced lung injury in vivo

Interleukin (IL)-10 has been shown to reduce many inflammatory reactions. We investigated the in vivo effects of IL-10 on a bleomycin-induced lung injury model. Hemagglutinating virus of Japan (HVJ)-liposomes containing a human IL-10 expression vector (hIL10-HVJ) or a balanced salt solution as a control (Cont-HVJ) was intraperitoneally injected into mice on day -3. This was followed by intratracheal instillation of bleomycin (0.8 mg/kg) on day 0. Myeloperoxidase activity of bronchoalveolar lavage fluid and tumor necrosis factor-alpha mRNA expression in bronchoalveolar lavage fluid cells on day 7 and hydroxyproline content of the whole lung on day 21 were inhibited significantly by hIL10-HVJ treatment. However, Cont-HVJ treatment could not suppress any of these parameters. We also examined the in vitro effects of IL-10 on the human lung fibroblast cell line WI-38. IL-10 significantly reduced constitutive and transforming growth factor-beta-stimulated type I collagen mRNA expression. However, IL-10 did not affect the proliferation of WI-38 cells induced by platelet-derived growth factor. These data suggested that exogenous IL-10 may be useful in the treatment of pulmonary fibrosis.

[Sitting position in the neurosurgery: the results of a questionnaire sent to neurosurgeons of medical colleges]

We analyzed questionnaire on the sitting position among neurosurgeons. We sent questionnaire to 80 medical colleges in Japan and obtained response from 61 universities (76.3%). The sitting position surgery was performed in 7 institutions (11.5%) and was not in other 54 (88.5%). The first reason for not adopting the sitting position was "other position was good enough to perform the surgery" (44 institutions, 81%). This reason exceeded "objection from the anesthesiologist" (17 institutions, 31%). Twenty institutions (33%) adopted or wished to perform the surgery in sitting position, indicating that neurosurgeons still are interest in performing the sitting position surgery. But 6 institutions adopting the sitting position predicted that the sitting position would diminish in the future, and the sitting position surgery would decrease in number in Japan.

Isolation of Pseudomonas aeruginosa from Ushubetsu River water in Hokkaido, Japan

To provide information on the ecology of Pseudomonas aeruginosa in nature, bacteriological surveillance was performed in the defined area in Hokkaido, Japan. P. aeruginosa was isolated from water samples of Ushubetsu River in the down stream from the urban area of Asahikawa. P. aeruginosa was isolated from fecal samples of pigs but not from samples of soil of a tomato field, sand of sandboxes in vest-pocket parks, fresh vegetables, or feces of wild deer. The present results indicate that P. aeruginosa strains isolated from the river water is originated from the environment of human activity and not from wild life or domestic animals.

Volume expansion sensitivity of swelling-activated Cl(-) channel in human epithelial cells

In human epithelial cell lines, whole-cell swelling-activated Cl(-) current was not directly correlated to cell volume per se, membrane tension or hydrostatic pressure. The current density exhibited a relation described by a Boltzmann function to the square of the cell diameter. Cytochalasin D enhanced the volume sensitivity. These results suggest that the activation mechanism of volume-sensitive Cl(-) channel is related to cytoskeleton-dependent membrane spring energy in human epithelial cells.

Prevalence of migraine and Raynaud's phenomenon in Japanese patients with vasospastic angina

The prevalence of migraine and Raynaud's phenomenon in Japanese patients with vasospastic angina (group I) were compared with those in 2 control groups: one with effort angina (group II) and the other group without known ischemic heart disease (group III). There were no significant differences among the 3 groups with respect to age and sex. The prevalence of migraine in group I was 23 of 100, as compared with 4 of 100 in group II (p<0.01) and 11 of 100 in group III (p<0.05). The prevalence of Raynaud's phenomenon in group I was 9 of 100, as compared with 3 of 100 in group II and 4 of 100 in group III. Thus, in Japan, the prevalence of migraine in patients with vasospastic angina was higher than those in the 2 control groups, whereas the prevalence of Raynaud's phenomenon did not differ significantly among the 3 groups. The prevalence of Raynaud's phenomenon in Japanese patients with vasospastic angina was different from that reported from North America, although the prevalence of migraine was the same. This may be partially explained by racial differences.

Avian influenza virus intranasally inoculated infects the central nervous system of mice through the general visceral afferent nerve

To define the route of influenza virus invasion into the central nervous system (CNS), an avian influenza A (H5N3) virus was inoculated into mice intranasally or intravenously. Only the intranasal infection group mice showed depression and retention of gas in the digestive system. Pathological findings in the animals were bronchointerstitial pneumonia and non-suppurative encephalitis restricted to the brain stem. The nerve nucleus primarily affected was the nucleus of solitary tract. Prior to the development of the CNS lesions, viral antigen was detected in vagal and trigeminal ganglia. These results suggest that the primarily replicated virus in the respiratory mucosa ascended to the CNS via sensory nerve routes, inducing lesions in the brain stem, and then spread trans-synaptically in the CNS.

Influenza virus-induced encephalopathy: clinicopathologic study of an autopsied case

BACKGROUND

Rapid progressive encephalopathy with a high fever, consciousness loss and recurrent convulsions has been occasionally reported in children during influenza pandemics in Japan since 1995. We examined a 2-year old girl with hemorrhagic shock and encephalopathy syndrome associated with acute influenza A virus infection (A/Nagasaki/76/98; H3N2), to answer several questions for which no histologic or virologic data exist.

METHODS

A clinicopathologic study using immunohistochemical staining and viral genome detection by reverse transcriptase polymerase chain reaction (RT-PCR) was performed with this autopsied case.

RESULTS

The virus antigen was positive in CD8+ T lymphocytes from the lung and spleen. The virus infected a very limited part of the brain, especially Purkinje cells in the cerebellum and many neurons in the pons, without inducing an overt immunologic reaction from the host. The RT-PCR used for detecting the hemagglutinin gene demonstrated positive bands in all frozen tissues and cerebrospinal fluid taken at autopsy and not in samples obtained on admission.

CONCLUSIONS

The pathologic change induced by the direct viral invasion cannot be responsible for all of the symptoms, especially for the rapid and severe clinical course of the disease within 24-48 h after the initial respiratory symptoms. Together with the rapid production of several inflammatory cytokines, the breakdown of the blood-brain barrier may induce severe brain edema and can be a major pathologic change for the disease. Any therapeutic strategy to control this multistep progression of the disease could be effective.

Hypothermia with acute renal failure in a patient suffering from diabetic nephropathy and malnutrition

We report a rare case of hypothermia with acute renal failure in a patient suffering from diabetic nephropathy. A 71-year-old male who had been receiving insulin therapy for the treatment of diabetes mellitus complicated with advanced diabetic nephropathy since 1998 was malnourished with an extremely decreased muscle mass. Without any prolonged exposure to excessively low external temperatures or hypothyroidism, pituitary insufficiency, adrenal insufficiency, sepsis, hypoglycemia, and diabetic ketoacidosis, acute hypothermia appeared together with an aggravation of diabetic nephropathy. His skin temperature fell to below measurable levels and his rectal temperature fell to 30.0 degrees C. His consciousness was drowsy and the hypothermia was not accompanied by shivering. Skeletal muscle is known to play an important role as a center of heat production and shivering thermogenesis in skeletal muscle mainly operates on acute cold stress. Therefore, in this case, hypothermia may have occurred because the shivering thermogenesis could not fully act on the acute cold stress due to the dramatically reduced muscle mass. We should always keep in mind that older, malnourished diabetic patients can easily suffer from impairments of the thermoregulatory system.

Substitution of amino acid residue in influenza A virus hemagglutinin affects recognition of sialyl-oligosaccharides containing N-glycolylneuraminic acid

Sialic acids are essential components of cell surface receptors used by influenza viruses. To determine the molecular mechanisms of viral recognition of two major species of sialic acids, N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (Neu5Gc), we tested the binding reactivity of nine human H3 influenza A viruses to sialylglycolipids containing type II sugar chain and different molecular species of terminal sialic acids. All human H3 viruses tested except A/Memphis/1/71 bound both Neu5Ac and Neu5Gc. Nucleotide sequence analysis suggests that amino acids at 143, 155, and 158 are linked to the viral recognition of Neu5Gc.

[The role of monocyte chemotactic and activating factor (MCAF)/monocyte chemoattractant protein (MCP)-1 in subgroups of rapidly progressive glomerulonephritis]

To elucidate the role of monocyte chemotactic and activating factor (MCAF)/monocyte chemoattractant protein(MCP)-1 in the pathogenesis of rapidly progressive glomerulonephritis (RPGN), we determined the urinary levels of MCAF/MCP-1 in 20 healthy subjects, 30 patients showing RPGN with crescents, and 39 patients with various types of renal diseases without crescents. We divided RPGN into two subgroups, the acute type and the insidious type, with regard to the declination rate of reciprocals of serum creatinine with time as previously reported. In addition, we divided the patients with RPGN into anti-neutrophil cytoplasmic antibody(ANCA)-related diseases and immune complex(IC)-mediated diseases with regard to etiology. Urinary levels of MCAF/MCP-1 were significantly higher in patients with RPGN as compared with those of other renal diseases and healthy volunteers(21.8 +/- 4.5 vs. 11.6 +/- 3.5, 1.0 +/- 0.1 pg/ml creatinine, respectively, p < 0.01, mean +/- SEM). There was no difference in the urinary levels of MCAF/MCP-1 between the acute and insidious types of RPGN patients. In addition, there was no difference in the urinary levels of MCAF/MCP-1 between the patients with ANCA-related and IC-mediated diseases. Urinary levels of MCAF/MCP-1 in patients with RPGN were correlated well with the percentage of both total crescents and fibrocellular/fibrous crescents and the number of CD68-positive infiltrating cells in the interstitium. Immunohistochemical examinations revealed that MCAF/MCP-1 positive cells were detected in tubular epithelial and endothelial cells and mononuclear infiltrated cells in the interstitium. Moreover, elevated urinary MCAF/MCP-1 levels in patients with RPGN, regardless of subgroups, were dramatically decreased during methylprednisolone pulse therapy induced convalescence. These results suggest that MCAF/MCP-1 may be involved in the pathogenesis of RPGN via macrophage recruitment and activation.

Avirulent Avian influenza virus as a vaccine strain against a potential human pandemic

In the influenza H5N1 virus incident in Hong Kong in 1997, viruses that are closely related to H5N1 viruses initially isolated in a severe outbreak of avian influenza in chickens were isolated from humans, signaling the possibility of an incipient pandemic. However, it was not possible to prepare a vaccine against the virus in the conventional embryonated egg system because of the lethality of the virus for chicken embryos and the high level of biosafety therefore required for vaccine production. Alternative approaches, including an avirulent H5N4 virus isolated from a migratory duck as a surrogate virus, H5N1 virus as a reassortant with avian virus H3N1 and an avirulent recombinant H5N1 virus generated by reverse genetics, have been explored. All vaccines were formalin inactivated. Intraperitoneal immunization of mice with each of vaccines elicited the production of hemagglutination-inhibiting and virus-neutralizing antibodies, while intranasal vaccination without adjuvant induced both mucosal and systemic antibody responses that protected the mice from lethal H5N1 virus challenge. Surveillance of birds and animals, particularly aquatic birds, for viruses to provide vaccine strains, especially surrogate viruses, for a future pandemic is stressed.

The short- and long-term outcomes of membranous nephropathy treated with intravenous immune globulin therapy. Kanazawa Study Group for Renal Diseases and Hypertension

BACKGROUND

A considerable diversity in prognosis is seen with membranous nephropathy (MN). A recent report showed beneficial effects of immune globulin (Glb) therapy in Heymann nephritis, a rat model of MN. However, the early and late clinical effects of Glb in human MN have remained unclear.

METHODS

We studied retrospectively 86 patients with primary MN from 1965 to 1988 who were followed for at least 5 years, or until renal or actual death. Thirty patients were non-randomly treated with 1-3 courses of intravenous immune globulin, 5-10 g/day (100-150 mg/kg/day) for 6 consecutive days. Based on electron microscopic (EM) findings, the patients were divided into two subtypes, i.e. homogeneous type with synchronous electron-dense deposits, and heterogeneous type with various stages of dense deposits, due to their different clinical outcomes.

RESULTS

There was no difference in the initial clinicopathological states between Glb (n = 30) and non-Glb group (n = 56) (70 vs. 68% in nephrotic state; 37 vs. 39% in female, 50 vs. 52% in homogeneous type, 50 vs. 48% in heterogeneous type respectively). For the homogeneous type, at 6 months post-treatment, Glb therapy had induced earlier remission as compared to non-Glb treatments with corticosteroid alone or together with cyclophosphamide (57 vs. 10% respectively, P = 0.006). However, there was no significant difference in the early therapeutic effect for the heterogeneous type (13% for Glb vs. 5% for non-Glb in remission after 6 months), or in the final outcome for all groups (18% for Glb vs. 10% for non-Glb in renal death after 15 years). No adverse effects were recorded during or after Glb therapy.

CONCLUSIONS

Our results suggest that short-term relatively low-dose intravenous Glb therapy has a beneficial effect in the earlier induction of remission in a subgroup of MN, the homogeneous type with EM findings of synchronous electron-dense deposits, but does not alter the long-term outcome of human MN.

Resistance to pseudorabies virus infection in transgenic mice expressing the chimeric transgene that represses the immediate-early gene transcription

A chimeric gene encoding a fusion protein consisting of the DNA-binding domain of the immediate-early (IE) protein of pseudorabies virus (PRV) and a tail-truncated VP16 of herpes simplex virus 1, lacking the transcription activation domain, has been shown to repress transcription of the PRV IE gene, resulting in the inhibition of PRV growth in vitro. To assess the antiviral potential of the fusion protein in vivo, transgenic mice containing the chimeric gene under the control of the virus- and interferon-inducible Mx 1 promoter were generated. A transgenic mouse line showed marked resistance to PRV infection when the mice were challenged intranasally with PRV. Inhibition of PRV replication was also observed in monolayers of embryonic cells prepared from the transgenic mice. In the cells infected with PRV, transcription of the PRV IE gene was repressed. The present results indicate that the chimeric gene is able to exert a significant antiviral effect against PRV infection in vivo.

Structure of the immediate early gene of canine herpesvirus

The nucleotide sequence of the immediate early (IE) gene of canine herpesvirus was determined. This gene was located in the inverted repeat regions, encoding a polypeptide of 1,383 amino acids. The predicted amino acid sequence was most closely related to that of the feline herpesvirus 1 IE protein among those of other alphaherpesviruses. DNA binding and transcriptional activation domains were found in the IE protein. A spliced region of the IE gene transcript was determined in its 5' non-coding region.