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Biomedical subjects

C J Gibbs

Publications and source records attributed to C J Gibbs.

At least 19 recordsLinked to original sources
PubMed2001

Tropical spastic paraparesis.

Human T-cell lymphotropic virus type I (HTLV-I) is the cause of endemic tropical spastic paraparesis (TSP) or HTLV-I-associated myelopathy (HAM). Because TSP/HAM is not a fatal disease, the neuropathology of this disease, albeit relatively well understood, is based on the examination of just a few incidental cases. We summarise our experience with the neuropathology of tropical spastic paraparesis/HTLV-I associated myelopathy (TSP/HAM). We studied three cases of TSP/HAM from different parts of the world. We demonstrated peculiar lamellated structures, called "multilamellar bodies" (MLB). It is tempting to suggest that MLB may represent specific ultrastructural markers of TSP/HAM. The pathology of the anteriorand posterior horns was similar and comprised axonal degeneration, accompanied by extensive astrocytic gliosis. Lymphocytic infiltration, particularly observed as "cuffs" around blood vessels, was scattered among other cellular elements. Ultrastructurally, myelin sheaths were relatively well preserved, and some demyelinated but not remyelinated fibres were observed. Moreover, axons with abnormal accumulations of neurofilaments, suggestive of axonal degeneration, were detected. Several axons contained Hirano bodies. In many samples glial processes replaced most of the remaining neuropil.

Ganglia, Spinal↗
PubMed2000

New studies on the heat resistance of hamster-adapted scrapie agent: threshold survival after ashing at 600 degrees C suggests an inorganic template of replication.

One-gram samples from a pool of crude brain tissue from hamsters infected with the 263K strain of hamster-adapted scrapie agent were placed in covered quartz-glass crucibles and exposed for either 5 or 15 min to dry heat at temperatures ranging from 150 degrees C to 1,000 degrees C. Residual infectivity in the treated samples was assayed by the intracerebral inoculation of dilution series into healthy weanling hamsters, which were observed for 10 months; disease transmissions were verified by Western blot testing for proteinase-resistant protein in brains from clinically positive hamsters. Unheated control tissue contained 9.9 log(10)LD(50)/g tissue; after exposure to 150 degrees C, titers equaled or exceeded 6 log(10)LD(50)/g, and after exposure to 300 degrees C, titers equaled or exceeded 4 log(10)LD(50)/g. Exposure to 600 degrees C completely ashed the brain samples, which, when reconstituted with saline to their original weights, transmitted disease to 5 of 35 inoculated hamsters. No transmissions occurred after exposure to 1, 000 degrees C. These results suggest that an inorganic molecular template with a decomposition point near 600 degrees C is capable of nucleating the biological replication of the scrapie agent.

Animals↗
PubMed2000

Immunophenotyping of peripheral blood, ranges of serum chemistries and clinical hematology values of healthy chimpanzees (Pan troglodytes).

This paper presents clinical chemistry, hematology and immunophenotyping data from 102 chimpanzees over a 2-year period. The groupings were: 3 years or less, 4-7 years, and 8 + years. These data are intended to augment formerly published information on these parameters and to serve as a concise reference guide for primate veterinarians and researchers for whom these data may be useful. This study has larger samplings than previously published data and more panel constituents by immunophenotyping.

Animals↗
PubMed2000

An enzyme-linked immunosorbent assay to quantify 14-3-3 proteins in the cerebrospinal fluid of suspected Creutzfeldt-Jakob disease patients.

The detection of 14-3-3 protein by Western immunoblot is a sensitive and specific cerebrospinal fluid marker of Creutzfeldt-Jakob disease (CJD). We developed a quantitative enzyme-linked immunosorbent assay (ELISA) that reliably detects 14-3-3 in cerebrospinal fluid. In a prospective study of 147 cerebrospinal fluid samples, the mean 14-3-3 concentration among pathologically confirmed CJD patients (28.0+/-20.6 ng/ml, n = 41) is significantly higher than the mean in the cerebrospinal fluid of those with other neurological disorders (3.1+/-2.9 ng/ ml, n = 84). At a cutoff value of 8.3 ng/ml, the ELISA has a sensitivity of 92.7% and a specificity of 97.6%. The 14-3-3 ELISA supports a diagnosis of CJD in patients who fulfill clinical criteria for possible CJD.

14-3-3 Proteins↗
PubMed1999

Novel PRNP sequence variant associated with familial encephalopathy.

Human transmissible spongiform encephalopathies (TSEs) are a group of chronic progressive neurodegenerative disorders that may be hereditary, infectious, or sporadic. Hereditary TSEs are associated with mutations in the PRNP gene on chromosome 20p12-pter. We report on a family in which seven patients developed limb and truncal ataxia, dysarthria, myoclonic jerks, and cognitive decline. The age of onset in the 30s, 40s, or 50s, prolonged disease duration, cerebellar atrophy on imaging, and the presence of synchronic periodic discharges on electroencephalogram suggested a familial encephalopathy resembling Gerstmann-Sträussler-Scheinker disease. A novel H187R mutation has been identified in affected, but not in unaffected, family members or unrelated controls suggesting a pathogenic role for this mutation. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 88:653-656, 1999. Published 1999 Wiley-Liss, Inc.

Adult↗
PubMed1999

Early induction of protein nexin-I in scrapie.

We used RNA fingerprinting by arbitrary primed PCR to identify genes whose expression is up-regulated in the brain of hamsters affected by prion disease. One gene implicated by RNA fingerprinting encoded the hamster homologue of protein nexin-I (PN-I), a serine proteinase inhibitor, and was further investigated by Northern blot analysis. PN-I mRNA levels were increased at pre-clinical stages (19 days after inoculation) and remained elevated when the spongiform encephalopathy was anatomopathologically and clinically evident (at 50 and 80 days). Future RNA screening conducted as illustrated may help to reveal a spectrum of genes relevant for the etiopathogenesis and/or diagnosis of prion disease.

Animals↗
PubMed1999

Increased levels of epsilon and gamma isoforms of 14-3-3 proteins in cerebrospinal fluid in patients with Creutzfeldt-Jakob disease.

We established four hybridoma cell lines producing monoclonal antibodies (MAbs) against 14-3-3 proteins. Immunoblot analysis revealed that epsilon and gamma isoforms were specifically increased in premortem cerebrospinal fluid samples from patients with sporadic Creutzfeldt-Jakob disease. Furthermore, dot immunoblot analysis showed that MAbs were more specific for native antigen than polyclonal antibodies were.

14-3-3 Proteins↗
PubMed1999

Creutzfeldt-Jakob disease diagnosable by EEG and cerebrospinal fluid analysis without brain biopsy: a case report.

This case illustrates a classic example of CJD in its clinical presentation and course and the EEG. It also shows dramatically the utility of a newly developed protein assay in the diagnosis of this disease. This assay has the potential of eliminating the need for brain biopsy in most cases, thus providing a safer diagnostic method for both staff and patients. In addition, the case points out that anatomical structural studies such as CT and MRI do not replace the utility of EEG in the comprehensive evaluation of rapid onset dementia, but rather complement the usefulness of EEG.

Cerebrospinal Fluid Proteins↗
PubMed1999

Evidence for widespread infection of wild rats with hepatitis E virus in the United States.

Hepatitis E is an important medical pathogen in many developing countries but is rarely reported from the United States, although antibody to hepatitis E virus (anti-HEV) is found in > 1% of U.S. citizens. Zoonotic spread of the virus is suspected. Sera obtained from 239 wild rats trapped in widely separated regions of the United States were tested for anti-HEV. Seventy-seven percent of rats from Maryland, 90% from Hawaii, and 44% from Louisiana were seropositive for anti-HEV. Rats from urban as well as rural areas were seropositive and the prevalence of anti-HEV IgG increased in parallel with the estimated age of the rats, leading to speculation that they might be involved in the puzzling high prevalence of anti-HEV among some U.S. city dwellers. The discovery of a in rats in the United States and the recently reported discovery that HEV is endemic in U.S. swine raise many questions about transmission, reservoirs, and strains of HEV in developed countries.

Animals↗
PubMed1998

Adenovirus-mediated human immunodeficiency virus-1 Nef expression in human monocytes/macrophages and effect of Nef on downmodulation of Fcgamma receptors and expression of monokines.

To characterize the effect of human immunodeficiency virus-1 (HIV-1) nef expression in human monocytes/macrophage (HMO) and U937 on the levels of FcgammaRs, HLA antigens, and monokines, elutriated HMOs and U937 cells were transfected with an adenovirus-mediated Nef expression system. Nef-expressing cells downmodulated FcgammaRI, FcgammaRII, and upregulated HLA class I molecules. Nef-expressing HMOs, treated with lipopolysaccharide (LPS) or phorbol 12-myristate 13-acetate (PMA), overexpressed tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and IL-10. However, IL-6 was induced by LPS and inhibited by PMA. Additionally, a subpopulation of Nef-expressing HMOs underwent apoptosis. Our data suggest that HIV-1 nef downmodulated FcgammaRs in myeloid cells in a manner similar to that previously reported for its effect on CD4+ in T cells.

3T3 Cells↗
PubMed1998

Phenotypic variability of Gerstmann-Sträussler-Scheinker disease is associated with prion protein heterogeneity.

Gerstmann-Sträussler-Scheinker disease (GSS), a cerebello-pyramidal syndrome associated with dementia and caused by mutations in the prion protein gene (PRNP), is phenotypically heterogeneous. The molecular mechanisms responsible for such heterogeneity are unknown. Since we hypothesize that prion protein (PrP) heterogeneity may be associated with clinico-pathologic heterogeneity, the aim of this study was to analyze PrP in several GSS variants. Among the pathologic phenotypes of GSS, we recognize those without and with marked spongiform degeneration. In the latter (i.e. a subset of GSS P102L patients) we observed 3 major proteinase-K resistant PrP (PrPres) isoforms of ca. 21-30 kDa, similar to those seen in Creutzfeldt-Jakob disease. In contrast, the 21-30 kDa isoforms were not prominent in GSS variants without spongiform changes, including GSS A117V, GSS D202N, GSS Q212P, GSS Q217R, and 2 cases of GSS P102L. This suggests that spongiform changes in GSS are related to the presence of high levels of these distinct 21-30 kDa isoforms. Variable amounts of smaller, distinct PrPres isoforms of ca. 7-15 kDa were seen in all GSS variants. This suggests that GSS is characterized by the presence PrP isoforms that can be partially cleaved to low molecular weight PrPres peptides.

Adult↗
PubMed1997

Phylogenetic analysis of simian T-lymphotropic virus Type I (STLV-I) in common chimpanzees (Pan troglodytes): evidence for interspecies transmission of the virus between chimpanzees and humans in Central Africa.

Serum and peripheral blood leukocytes from the chimpanzees (Pan troglodytes) of the colony of the Laboratory of Central Nervous System Studies, National Institute of Neurological Disorders and Stroke, NIH, were tested for the presence of STLV-I-specific antibodies and proviral DNA. Antibodies were determined by gelatin particle agglutination and Western blot (WB) assays utilizing HTLV-I antigens. Proviral DNA was detected by four PCR assays targeting three different regions of STLV-I genome: the fragments of the env and pol genes and LTR. Twenty of twenty-two DNA samples from WB-positive animals were PCR positive. None of the DNA samples from WB-negative (n = 5) and WB-indeterminate (n = 4) animals was PCR positive. The results of the nested and double nested env PCR tests were fully concordant; the seminested LTR PCR test was much less sensitive. The DNA sequences from the env (483 bp) and the pol (200 bp) genes and LTR (705 bp) were determined for six, two, and two chimpanzee STLV-I isolates, respectively. Phylogenetic analysis revealed that chimpanzee STLV-I isolates can be attributed to three clades. The first of these clades (SS-PTR1/CSA) included STLV-I isolates from the chimpanzees and West African subspecies of African green monkeys (Cercopithecus a. sabaeus). The other clades (S-PTR2 and S-PTR3) included STLV-I isolates only from chimpanzees. However, both S-PTR2 and S-PTR3 clustered together with Central African HTLV-I comprising the human/simian clade (HS-HSA/PTR). This pattern of phylogenetic clustering suggests that interspecies transmission of STLV-I occurred between chimpanzees and African green monkey subspecies as well between chimpanzees and human populations in Central Africa.

Africa, Central↗
PubMed1997

Immuno-electron microscopy reveals that the excitotoxin quinolinate is associated with the plasma membrane in human peripheral blood monocytes/macrophages.

Quinolinate (QUIN), a tryptophan-derived excitotoxin, was localized ultrastructurally in human peripheral blood monocytes/macrophages (MO) by immuno-electron microscopy. A combined carbodiimide/glutaraldehyde/paraformaldehyde-based fixation procedure was developed for optimal retention of QUIN in the cell as well as minimal loss of ultrastructure; a silver-enhanced colloidal gold detection system was used for electron-microscopic analysis. Gold particles representing QUIN immunoreactivity were associated with the inner side of the plasma membrane in normal MO. The number of gold particles increased significantly when QUIN levels were elevated by treatment with its precursor kynurenine, but location of the gold particles remained essentially the same under this condition. Treatment with interferon-gamma increased the number of Golgi bodies, vacuoles and pseudopodia, reflecting the activated state of the cell. Significantly increased numbers of gold particles representing QUIN were detectable in approximately the same location as in the case of kynurenine treatment. Combined treatment with kynurenine and interferon-gamma maximally increased the number of gold particles at the periphery of the cell. The pseudopodia were intensely stained with gold particles, while they were not detectable in the inner part of the cytoplasm or in any other organelle even under this activated condition. The significance of the specific location of QUIN revealed in the present study and its relation to the release and subsequent actions of QUIN are discussed.

Cell Membrane↗
PubMed1997

Normal isoform of amyloid protein (PrP) in brains of spawning salmon.

The transmissible spongiform encephalopathies are a group of subacute progressive degenerative diseases of the nervous system which are always fatal in their outcome. These diseases appear to be caused by the abnormal isoform of the precursor protein of amyloid designated prion protein. The normal isoform has been identified in the tissues of all mammalian species thus far tested as well as in Drosophila. We report the presence of this protein for the first time in the brains of fish.

Animals↗
PubMed1997

Myelopathy among Brazilians coinfected with human T-cell lymphotropic virus type I and HIV.

OBJECTIVE: To determine whether subjects coinfected with HTLV-I and HIV have a higher frequency of myelopathy than subjects singly infected with HIV. DESIGN: A prospective, nested case-control study of HTLV-I and HIV coinfected (cases) and HIV singly infected adults (controls) participating in a prospective HIV cohort study at a university hospital outpatient HIV clinic in Rio de Janeiro, Brazil. MEASUREMENTS: Subjects were evaluated for evidence of myelopathy by a neurologist unaware of their HTLV serologic status. Patients with at least two pyramidal signs, such as paresis, hypertonicity or spasticity, hyperreflexia, clonus, diminished or absent superficial reflexes, or the presence of pathologic reflexes (e.g., Babinski or Hoffmann), were defined as having myelopathy. Myelopathy severity was quantified using the Kurtzke Functional Disability Scale (FDS); patients with FDS scores > or = 4 were considered to have significant myelopathy. Selected patients with myelopathy underwent lumbar puncture for the evaluation of intrathecal synthesis of HTLV-I antibodies. RESULTS: Of 15 coinfected subjects, 11 (73%) had evidence of myelopathy versus 10 of 62 subjects (16%) with HIV single infection (adjusted odds ratio [OR] = 13.0, p = 0.00002). When only myelopathy patients with FDS scores of > or = 2 or > or = 4 were included, the association between coinfection and the presence of myelopathy remained (OR = 7.3, p = 0.0003 for scores > or = 2; and OR = 8.9 for scores > or = 4, p = 0.04). In addition, a higher proportion of coinfected subjects had peripheral neuropathy (40%) than controls (16%) (OR = 3.5, p = 0.07). CONCLUSION: Coinfection with HTLV-I was strongly associated with myelopathy among subjects infected with HIV. The relative contribution of HTLV-I versus HIV in the pathogenesis of coinfection-associated myelopathy is not known. Coinfection may also be associated with peripheral neuropathy. Further studies are needed to elucidate the mechanisms of coinfection-associated neurologic conditions.

Adult↗
PubMed1996

The 14-3-3 brain protein in cerebrospinal fluid as a marker for transmissible spongiform encephalopathies.

BACKGROUND: There is no practical and reliable premortem test for Creutzfeldt-Jakob disease and the related transmissible spongiform encephalopathies. Two proteins, designated 130 and 131, which have been detected in low concentrations in cerebrospinal fluid from patients with Creutzfeldt-Jakob disease, appear to be sensitive and specific markers for the disease. Attempts to identify these proteins, however, have been unsuccessful. We hypothesized that they may be present in the normal brain. METHODS: We detected proteins 130 and 131 in normal human brain, partially sequenced their amino acids, and found that they matched the brain protein known as 14-3-3. We then developed a simple, rapid immunoassay for this protein and tested it in cerebrospinal fluid samples from 71 humans and 30 animals with spongiform encephalopathies and in control samples from 186 humans and 94 animals. RESULTS: The immunoassay detected the 14-3-3 protein in cerebrospinal fluid from 68 of the 71 patients with Creutzfeldt-Jakob disease (96 percent, 95 percent confidence interval, 92 to 99 percent). Among 94 patients with other dementias, the specificity was 96 percent. If one excludes the three patients with dementia who had strokes within one month before testing, the specificity was 99 percent. The test was positive in 12 of 24 patients with viral encephalitis. In animals the sensitivity of the assay was 87 percent and the specificity was 99 percent. CONCLUSION: In patients with dementia, a positive immunoassay for the 14-3-3 brain protein in cerebrospinal fluid strongly supports a diagnosis of Creutzfeldt-Jakob disease. This finding, however, does not support the use of the test in patients without clinically evident dementia.

14-3-3 Proteins↗
PubMed1996

Immunocytochemical localization of the endogenous neuroexcitotoxin quinolinate in human peripheral blood monocytes/macrophages and the effect of human T-cell lymphotropic virus type I infection.

Quinolinate (Quin), a metabolite in the kynurenine pathway of tryptophan degradation and a neurotoxin that appears to act through the N-methyl-D-aspartate receptor system, was localized in cultured human peripheral blood monocytes/macrophages (PBMOs) by using a recently developed immunocytochemical method. Quin immunoreactivity (Quin-IR) was increased in gamma interferon (IFN-gamma)-stimulated monocytes/macrophages (MOs). In addition, the precursors, tryptophan and kynurenine, significantly increased Quin-IR. Infection of MOs by human T-cell lymphotropic virus type I (HTLV-I) in vitro substantially increased both the number of Quin-IR cells and the intensity of Quin-IR. At the peak of the Quin-IR response, about 40% of the cells were Quin-IR positive. In contrast, only about 2-5% of the cells were positive for HTLV-I, as detected by both immunofluorescence for the HTLV-I antigens and PCR techniques for the HTLV-I Tax gene. These results suggest that HTLV-I-induced Quin production in MOs occurs by an indirect mechanism, perhaps via cytokines produced by the infection but not directly by the virus infection per se. The significance of these findings to the neuropathology of HTLV-I infection is discussed.

Cells, Cultured↗