D. Puaoi - Academia.edu (original) (raw)

Papers by D. Puaoi

Research paper thumbnail of Neurological Abnormalities Associated with Feline Immunodeficiency Virus Infection

Journal of General Virology, 1994

Specific pathogen-free cats were infected with the Maryland strain of FIV (FIV-MD) for the purpos... more Specific pathogen-free cats were infected with the Maryland strain of FIV (FIV-MD) for the purpose of assessing the effects of FIV infection on the central nervous system (CNS). Two separate studies were performed, involving a total of 13 infected cats and six age-matched, sham-inoculated controls. All animals infected with FIV-MD seroconverted by 8 weeks post-infection and virus was recovered from peripheral blood mononuclear cells of all infected cats. All of the infected animals had lower absolute CD4+ cells counts and decreased CD4+/CD8+ ratios. Virus was recovered from the cerebrospinal fluid (CSF) of certain infected individuals, and antiviral antibody and pleocytosis were evident in the CSF of the majority of infected cats. Additionally, virus was recovered from tissue explants from the cerebellum, midbrain and brainstem of one sacrificed FIV+ cat. Specific neurological changes included anisocoria, delayed righting reflex and delayed pupillary reflex, as well as delayed visual and auditory evoked potentials, and marked alterations in sleep patterns similar to those reported for human immunodeficiency virus (HIV)-positive individuals. Histological evaluation revealed the presence of perivascular cuffing and glial nodules in FIV-infected cats. These results indicate that FIV causes an acute neurological disease that closely resembles the early neurological effects of HIV infection in humans and should serve well as an animal model for lentivirus-induced CNS disease.

Research paper thumbnail of The opaH locus of Neisseria gonorrhoeae MS11A is involved in epithelial cell invasion

Molecular Microbiology, 1994

In order to produce a successful infection, Neisseria gonorrhoeae (GC) must attach to and invade ... more In order to produce a successful infection, Neisseria gonorrhoeae (GC) must attach to and invade mucosal epithelial cells. To identify GC gene products involved in this early interaction with host cells we constructed a gene bank derived from a clinical isolate of GC, and isolated a clone which had the capacity to adhere to the human endometrial adenocarcinoma tissue-culture line HEC-1-B. The cloned sequence was identified as a member of the opa gene family whose protein products have been associated with virulence. The GC chromosome contains numerous variant opa genes which, in MS11, are designated opaA-K. Previous work showed that expression of opaC confers a highly invasive phenotype upon strain MS11. When our cloned opa gene was mutated and returned to the GC MS11A chromosome by transformation and homologous recombination, we isolated one transformant that was significantly reduced in its invasive capacity. The locus mutated in this transformant was identified as opaH. Our results indicate that invasiveness of GC for human epithelial cells can be determined by more than one opa gene in strain MS11A.

Research paper thumbnail of Transposition of Tn1545-delta 3 in the pathogenic Neisseriae: a genetic tool for mutagenesis

Journal of Bacteriology

The ability to study the virulence of pathogenic Neisseria spp. has been greatly limited by the a... more The ability to study the virulence of pathogenic Neisseria spp. has been greatly limited by the absence of genetic tools which allow the construction of defined mutants. We have engineered a transposon system which allows random mutagenesis of the Neisseria genome at relatively high frequency. Tn1545-delta 3 is a 3.4-kb derivative of the gram-positive transposon Tn1545 encoding resistance to kanamycin. Tn1545-delta 3 was subcloned into an erythromycin-resistant derivative of the mobilizable shuttle vector pLES2 to yield the plasmid pMGC20. This latter plasmid was introduced by conjugation from Escherichia coli S17-1 into Neisseria meningitidis 8013N and Neisseria gonorrhoeae 15063G. Kanamycin-resistant 8013N and 15063G transconjugants appeared at frequencies of 10(-5) and 10(-6), respectively. Restriction enzyme analysis and Southern blot hybridization of these transconjugants showed that, in Neisseria spp., the transposon excised spontaneously from pMGC20 and integrated into chromo...

Research paper thumbnail of Neurological Abnormalities Associated with Feline Immunodeficiency Virus Infection

Journal of General Virology, 1994

Specific pathogen-free cats were infected with the Maryland strain of FIV (FIV-MD) for the purpos... more Specific pathogen-free cats were infected with the Maryland strain of FIV (FIV-MD) for the purpose of assessing the effects of FIV infection on the central nervous system (CNS). Two separate studies were performed, involving a total of 13 infected cats and six age-matched, sham-inoculated controls. All animals infected with FIV-MD seroconverted by 8 weeks post-infection and virus was recovered from peripheral blood mononuclear cells of all infected cats. All of the infected animals had lower absolute CD4+ cells counts and decreased CD4+/CD8+ ratios. Virus was recovered from the cerebrospinal fluid (CSF) of certain infected individuals, and antiviral antibody and pleocytosis were evident in the CSF of the majority of infected cats. Additionally, virus was recovered from tissue explants from the cerebellum, midbrain and brainstem of one sacrificed FIV+ cat. Specific neurological changes included anisocoria, delayed righting reflex and delayed pupillary reflex, as well as delayed visual and auditory evoked potentials, and marked alterations in sleep patterns similar to those reported for human immunodeficiency virus (HIV)-positive individuals. Histological evaluation revealed the presence of perivascular cuffing and glial nodules in FIV-infected cats. These results indicate that FIV causes an acute neurological disease that closely resembles the early neurological effects of HIV infection in humans and should serve well as an animal model for lentivirus-induced CNS disease.

Research paper thumbnail of Neurological Abnormalities Associated with Feline Immunodeficiency Virus Infection

Journal of General Virology, 1994

Specific pathogen-free cats were infected with the Maryland strain of FIV (FIV-MD) for the purpos... more Specific pathogen-free cats were infected with the Maryland strain of FIV (FIV-MD) for the purpose of assessing the effects of FIV infection on the central nervous system (CNS). Two separate studies were performed, involving a total of 13 infected cats and six age-matched, sham-inoculated controls. All animals infected with FIV-MD seroconverted by 8 weeks postinfection and virus was recovered from peripheral blood mononuclear cells of all infected cats. All of the infected animals had lower absolute CD4 + cell counts and decreased CD4+/CD8 ÷ ratios. Virus was recovered from the cerebrospinal fluid (CSF) of certain infected individuals, and antiviral antibody and pleocytosis were evident in the CSF of the majority of infected cats.

Research paper thumbnail of Neurological Abnormalities Associated with Feline Immunodeficiency Virus Infection

Journal of General Virology, 1994

Specific pathogen-free cats were infected with the Maryland strain of FIV (FIV-MD) for the purpos... more Specific pathogen-free cats were infected with the Maryland strain of FIV (FIV-MD) for the purpose of assessing the effects of FIV infection on the central nervous system (CNS). Two separate studies were performed, involving a total of 13 infected cats and six age-matched, sham-inoculated controls. All animals infected with FIV-MD seroconverted by 8 weeks post-infection and virus was recovered from peripheral blood mononuclear cells of all infected cats. All of the infected animals had lower absolute CD4+ cells counts and decreased CD4+/CD8+ ratios. Virus was recovered from the cerebrospinal fluid (CSF) of certain infected individuals, and antiviral antibody and pleocytosis were evident in the CSF of the majority of infected cats. Additionally, virus was recovered from tissue explants from the cerebellum, midbrain and brainstem of one sacrificed FIV+ cat. Specific neurological changes included anisocoria, delayed righting reflex and delayed pupillary reflex, as well as delayed visual and auditory evoked potentials, and marked alterations in sleep patterns similar to those reported for human immunodeficiency virus (HIV)-positive individuals. Histological evaluation revealed the presence of perivascular cuffing and glial nodules in FIV-infected cats. These results indicate that FIV causes an acute neurological disease that closely resembles the early neurological effects of HIV infection in humans and should serve well as an animal model for lentivirus-induced CNS disease.

Research paper thumbnail of The opaH locus of Neisseria gonorrhoeae MS11A is involved in epithelial cell invasion

Molecular Microbiology, 1994

In order to produce a successful infection, Neisseria gonorrhoeae (GC) must attach to and invade ... more In order to produce a successful infection, Neisseria gonorrhoeae (GC) must attach to and invade mucosal epithelial cells. To identify GC gene products involved in this early interaction with host cells we constructed a gene bank derived from a clinical isolate of GC, and isolated a clone which had the capacity to adhere to the human endometrial adenocarcinoma tissue-culture line HEC-1-B. The cloned sequence was identified as a member of the opa gene family whose protein products have been associated with virulence. The GC chromosome contains numerous variant opa genes which, in MS11, are designated opaA-K. Previous work showed that expression of opaC confers a highly invasive phenotype upon strain MS11. When our cloned opa gene was mutated and returned to the GC MS11A chromosome by transformation and homologous recombination, we isolated one transformant that was significantly reduced in its invasive capacity. The locus mutated in this transformant was identified as opaH. Our results indicate that invasiveness of GC for human epithelial cells can be determined by more than one opa gene in strain MS11A.

Research paper thumbnail of Transposition of Tn1545-delta 3 in the pathogenic Neisseriae: a genetic tool for mutagenesis

Journal of Bacteriology

The ability to study the virulence of pathogenic Neisseria spp. has been greatly limited by the a... more The ability to study the virulence of pathogenic Neisseria spp. has been greatly limited by the absence of genetic tools which allow the construction of defined mutants. We have engineered a transposon system which allows random mutagenesis of the Neisseria genome at relatively high frequency. Tn1545-delta 3 is a 3.4-kb derivative of the gram-positive transposon Tn1545 encoding resistance to kanamycin. Tn1545-delta 3 was subcloned into an erythromycin-resistant derivative of the mobilizable shuttle vector pLES2 to yield the plasmid pMGC20. This latter plasmid was introduced by conjugation from Escherichia coli S17-1 into Neisseria meningitidis 8013N and Neisseria gonorrhoeae 15063G. Kanamycin-resistant 8013N and 15063G transconjugants appeared at frequencies of 10(-5) and 10(-6), respectively. Restriction enzyme analysis and Southern blot hybridization of these transconjugants showed that, in Neisseria spp., the transposon excised spontaneously from pMGC20 and integrated into chromo...

Research paper thumbnail of Neurological Abnormalities Associated with Feline Immunodeficiency Virus Infection

Journal of General Virology, 1994

Specific pathogen-free cats were infected with the Maryland strain of FIV (FIV-MD) for the purpos... more Specific pathogen-free cats were infected with the Maryland strain of FIV (FIV-MD) for the purpose of assessing the effects of FIV infection on the central nervous system (CNS). Two separate studies were performed, involving a total of 13 infected cats and six age-matched, sham-inoculated controls. All animals infected with FIV-MD seroconverted by 8 weeks post-infection and virus was recovered from peripheral blood mononuclear cells of all infected cats. All of the infected animals had lower absolute CD4+ cells counts and decreased CD4+/CD8+ ratios. Virus was recovered from the cerebrospinal fluid (CSF) of certain infected individuals, and antiviral antibody and pleocytosis were evident in the CSF of the majority of infected cats. Additionally, virus was recovered from tissue explants from the cerebellum, midbrain and brainstem of one sacrificed FIV+ cat. Specific neurological changes included anisocoria, delayed righting reflex and delayed pupillary reflex, as well as delayed visual and auditory evoked potentials, and marked alterations in sleep patterns similar to those reported for human immunodeficiency virus (HIV)-positive individuals. Histological evaluation revealed the presence of perivascular cuffing and glial nodules in FIV-infected cats. These results indicate that FIV causes an acute neurological disease that closely resembles the early neurological effects of HIV infection in humans and should serve well as an animal model for lentivirus-induced CNS disease.

Research paper thumbnail of Neurological Abnormalities Associated with Feline Immunodeficiency Virus Infection

Journal of General Virology, 1994

Specific pathogen-free cats were infected with the Maryland strain of FIV (FIV-MD) for the purpos... more Specific pathogen-free cats were infected with the Maryland strain of FIV (FIV-MD) for the purpose of assessing the effects of FIV infection on the central nervous system (CNS). Two separate studies were performed, involving a total of 13 infected cats and six age-matched, sham-inoculated controls. All animals infected with FIV-MD seroconverted by 8 weeks postinfection and virus was recovered from peripheral blood mononuclear cells of all infected cats. All of the infected animals had lower absolute CD4 + cell counts and decreased CD4+/CD8 ÷ ratios. Virus was recovered from the cerebrospinal fluid (CSF) of certain infected individuals, and antiviral antibody and pleocytosis were evident in the CSF of the majority of infected cats.