Hamida Qavi | University of Houston-Downtown (original) (raw)

Papers by Hamida Qavi

Sex Transm Dis, Mar 31, 1983

Virus isolated from a woman presenting with the first symptomatic episode of genital herpes was i... more Virus isolated from a woman presenting with the first symptomatic episode of genital herpes was identified as herpes simplex virus type 1 (HSV-1) by restriction nuclease fingerprinting. Testing for IgM antibody to HSV indicated that the patient had recently contracted a new HSV infection. Virus microneutralization and the micro-solid phase radioimmunometric test for IgG, however, showed that the patient had had prior infection with herpes simplex virus type 2 (HSV-2); thus the HSV-1 infection was acquired despite the presence of antibody to HSV-2. Genital herpes recurred about four, seven, and nine months after the HSV-1 infection. Isolates from the latter three episodes all were of an identical strain of HSV-2 and were not recombinants or a mixture of the viruses. The data show that two distinctly different herpes simplex viruses can initiate genital infections in one individual and suggest that HSV-2 is more likely to recur than HSV-1.

In vivo (Athens, Greece)

Rabbits were divided into three groups and infected with Human Herpesvirus Type 6 (HHV-6) or Herp... more Rabbits were divided into three groups and infected with Human Herpesvirus Type 6 (HHV-6) or Herpes Simplex Virus Type 1 (HSV 1). Infected eyes were swabbed and cultured every alternate day. At day 15 postinfection (PI), rabbits were sacrificed, trigeminal ganglia (TG) and corneas were analyzed for the presence or absence of viral DNA. The severity of keratitis was much greater in the eyes inoculated by both viruses and cultures from these animals were HSV-1 positive for 15 days PI as compared to 9 days PI for rabbits infected with HSV-1 alone. The corneas from infected eyes and the corresponding TGs from animals infected with HSV-1 were positive for HSV-1 DNA. HHV-6 DNA was recoverable from corneas of infected eyes, but not from the corresponding TGs. Although preliminary, these observations indicate that HHV-6 may enhance the HSV-1 expression in animals with dual infections.

Central European journal of public health

Cytomegalovirus (CMV) and Chlamydia pneumoniae (C. pneumoniae) antigens and DNA sequences have be... more Cytomegalovirus (CMV) and Chlamydia pneumoniae (C. pneumoniae) antigens and DNA sequences have been demonstrated in atherosclerotic plaques by several investigators. Most significantly, CMV DNA was found both in atherosclerotic lesions as well as in uninvolved areas of aortas and carotid artery, whereas C. pneumoniae was mostly detected in advanced carotid atherosclerotic lesions. Atherosclerotic plaques removed from seventeen patients during carotid endarterectomy were analysed for the simultaneous presence of CMV and C. pneumoniae DNA sequences using polymerase chain reaction (PCR). Of the seventeen samples, nine (53%) were positive for CMV DNA sequences and seven (41%) contained C. pneumoniae DNA sequences. Four samples (24%) were positive for both CMV and C. pneumoniae DNA. CMV DNA or C. pneumoniae DNA was detected in 12 (71%) of 17 carotid plaques and 2 additional patients had high titers of antibodies to CMV. CMV DNA and C. pneumoniae DNA were found in the same tissue specimen...

Central European journal of public health

Forty-three blood samples from atherosclerotic donors and 28 samples from normal individuals were... more Forty-three blood samples from atherosclerotic donors and 28 samples from normal individuals were analyzed to determine the frequency of occurrence of cytomegalovirus (CMV) and Chlamydia pneumoniae DNA sequences in lymphocytes of Saudi Arabian donors using Polymerase Chain Reaction (PCR). In non-atherosclerotic donors, no CMV DNA was detectable and only one sample was positive for C-pneumoniae DNA sequences. Of the 43 atherosclerotic patients, 22 were infected with CMV, 23 were infected with C-pneumoniae and 11 showed no infection. Thirteen of the 43 donors showed simultaneous infection with both CMV and C-pneumoniae. These results demonstrate that atherosclerotic patients are more frequently infected with CMV or C-pneumoniae or both.

Investigative ophthalmology & visual science, 1987

The current study analyzed the herpes simplex virus type 1 (HSV1) genome during suppressed and re... more The current study analyzed the herpes simplex virus type 1 (HSV1) genome during suppressed and reactivated infection in vitro. Utilization of 3H-labeled HSV1 provided a highly specific probe for intracellular localization, isolation, and characterization of the HSV genome after infection of rabbit trigeminal ganglion neurons. Restriction enzyme analysis of viral DNA extracted during both suppressed and reactivated infection matched that of the HSV1 control DNA. Viral DNAs extracted from both cellular and nuclear fractions of host cells exhibited identical patterns. No detectable alterations in terminal fragments were observed, which suggests that the HSV1 genome is both linear and nonintegrated during suppressed infection in this system.

In vivo (Athens, Greece)

Majority of AIDS patients experience visual loss due to AIDS-associated retinitis or commonly kno... more Majority of AIDS patients experience visual loss due to AIDS-associated retinitis or commonly known as CMV retinitis. It has been reported that CMV infection of the retina is a late manifestation of AIDS and a poor prognostic sign. The etiology and mechanism(s) involved in the development of AIDS-associated retinitis is currently unknown. It is of critical importance to understand the pathobiology of this disease process in order to develop a rational approach to therapeutic intervention. We have determined the frequency and proximity of simultaneous occurrence of HIV-1 and HHV-6 in retinal tissues of AIDS patients in the absence of CMV infection. Active infection of HIV-1 has been identified in the retinal tissues of 30-60% of AIDS patients analyzed. HHV-6 antigens and transcripts were detectable in about 50% of HIV-1 positive retinas. Most significant finding of our studies is the presence of HIV-1 and HHV-6 antigens and transcriptional activity in retinal tissue in the absence of...

Investigative ophthalmology & visual science, 1995

The purpose of this study was to define the agents involved in the development of acquired immune... more The purpose of this study was to define the agents involved in the development of acquired immune deficiency syndrome (AIDS)-associated retinitis. To achieve this goal, the authors determined the frequency and proximity of the simultaneous presence of human immunodeficiency virus (HIV)-1, human herpesvirus (HHV)-6, and human cytomegalovirus (HCMV) in retinas of patients with AIDS with and without AIDS-associated retinitis. Retinal sections from 50 globes from patients with AIDS were analyzed for the presence of viral antigens and transcripts. Group 1 contained 13 globes from patients with HCMV infection. Group 2 contained 20 globes from patients with retinal lesions of uncertain etiology in which HCMV antigen and transcripts were not detected. Group 3 contained 17 globes from patients with no retinal lesions. Retinal sections from all 13 globes (group 1) were positive for HCMV antigens and HIV-1 antigens and transcripts. Six of the 13 retinas were also positive for HHV-6 antigens an...

European journal of cancer & clinical oncology, 1982

Isozyme patterns for five acid hydrolases, acid phosphatase (AP), aryl-sulfate (AS), beta-glucuro... more Isozyme patterns for five acid hydrolases, acid phosphatase (AP), aryl-sulfate (AS), beta-glucuronidase (beta-Glu), N-acetylglucosaminidase (NAG) and beta-galactosidase (beta-Gal), were studied in isolated lysosomes from ethylnitrosourea (ENU)-induced gliomas and compared with normal and newborn rat brains. With polyacrylamide gel electrophoresis (PAGE), AP was separated into three bands, acidic (A), intermediate (B) and basic (C). In tumors and newborn brains there was a decrease in A and C but a significant increase in B. For NAG the acidic form was elevated by 9-19% in tumors, while newborn brains showed a 19% decrease. Even though the band intensities of beta-Glu in tumors and newborn brains were increased, the relative distribution remained similar to normal brain. With isoelectric focusing, five hydrolases were separated into four to five distinct forms. In ENU-induced gliomas the intensities of all peaks were considerably increased, but in most cases the number of isozymes re...

Virology, Jan 15, 1983

Five hybrid plasmids were constructed, each containing a portion of the vaccinia virus DNA HindII... more Five hybrid plasmids were constructed, each containing a portion of the vaccinia virus DNA HindIII-J fragment. These plasmid DNAs were used in marker rescue experiments to map the mutations in the thymidine kinase (TK) gene of three TK- vaccinia virus mutants. The TK gene of each of the three mutants was rescued by DNA from plasmid pPJ701, which contained about one-half of the HindIII-J fragment. Two mutants, 1004B and 1017-1, but not the third, 1016-1, were rescued by DNA of two plasmids, pPJ702 and pPJ703, which contained 16 and 18%, respectively, of one end of the J fragment. Mutant 1016-1 could be rescued by plasmid pPJ705 containing a 1.69-kb fragment of the HindIII-J fragment. The J fragment DNA in plasmid pPJ705 is located adjacent to that and separated by an EcoRI site from pPJ703 in the vaccinia virus genome. These results indicate that the mutation site in the TK gene of 1016-1 differs from that in 1004B or 1017-1 and suggests that the structural gene for the vaccinia viru...

Virology, 1980

ABSTRACT Human and mouse cells biochemically transformed by ultraviolet light (UV)-irradiated HSV... more ABSTRACT Human and mouse cells biochemically transformed by ultraviolet light (UV)-irradiated HSV-1 express HSV-1 thymidine kinase (TK) activity and also express type-specific herpesvirus-associated nuclear antigen(s) (HANA). To identify the HSV-1 DNA sequences coding for HANA and their location on the viral genome, studies were carried out on: (i) somatic cell hybrid clones obtained by fusing mouse [LM(TK−)] cells with UV-irradiated HSV-1-transformed human [HeLa(BU25)/KOS 8-1] cells; and (ii) LM(TK−) cells biochemically transformed with restriction endonuclease fragments of DNA which code for HSV-1 TK. Molecular hybridization experiments were also carried out and demonstrated that HSV-1 DNA sequences coding for TK were integrated in the biochemically transformed cells. The human-mouse somatic cell hybrid clones (LH81) which were HSV-1 TK+ were also HANA+, while clones counterselected in bromodeoxyuridine which had lost HSV-1 TK activity and DNA sequences likewise lost HANA. Previous studies had shown that the HSV-1 TK gene of LH81 hybrid clones was associated with a marker chromosome, designated M7, which consists of a human chromosome 17 translocated to the short arm of chromosome 3, or a modified M7 chromosome containing a translocation from a mouse chromosome. The present results indicate that at least one HANA gene was integrated in the same chromosome as the HSV-1 TK gene. LM(TK−) cells biochemically transformed by HSV-1 DNA restriction nuclease fragments of diminishing size, which map in the HpaI-I region (26.2 to 31.7) of the HSV-1 genome, were HANA+ as well as TK+. The HANA+ cells included LM(TK−)/TF pAGO PP and LM(TK−)/TF pAGO PS clones. The latter are clones of LM(TK−) cells biochemically transformed, respectively, by a PvuII fragment (1.35 × 106 daltons) and a PvuII-SmaI fragment (0.9 × 106 daltons; 30.2 to 31.1 map units) of HSV-1 DNA derived from Escherichia coli plasmid, pAGO. Since the PvuII-SmaI DNA fragment has only enough genetic information to code for a polypeptide of about 53,000 daltons and the HSV-1 TK polypeptide is about 40,000 daltons, the findings indicate that the genes for HSV-1 TK and one herpesvirus-associated nuclear antigen are either contiguous or overlapping, or HSV-1 TK and one HANA gene are identical.

Virology, 1981

ABSTRACT In order to delimit the approximate boundaries of the marmoset herpesvirus (MarHV) thymi... more ABSTRACT In order to delimit the approximate boundaries of the marmoset herpesvirus (MarHV) thymidine kinase (TK) gene, HindIII and BamHI digests of MarHV DNA were cloned in plasmid pBR322. Several recombinant plasmids which transformed E. coli K12 strain RR1 to ampicillin resistance were isolated. The MarHV DNA inserts in these plasmids accounted for about half of the MarHV genome. One of the plasmids, pMAR4, contained a 9.1-kbp fragment of MarHV DNA (HindIII-G), transformed LM(TK−) cells to TK+, and hybridized to the BamHI-I fragment of MarHV DNA, which had previously been shown to have TK-transforming activity. pMAR4 DNA had little or no homology to the 2-kbp PuvII fragment of HSV-1 DNA, which contains the HSV-1 TK gene. Cleavage with PvuII, SacI, SmaI, and KpnI inactivated the TK-transforming activity of pMAR4, but cleavage with HindIII, PstI, EcoRI, XhoI, XbaI, and BamHI did not. Deletion mutants pMAR401 and pMAR420, which lacked the 2.6-kbp KpnI and the 2.75-kbp EcoRI fragments, respectively, of pMAR4, lost transforming activity, whereas pMAR410, which lacked a 2.9kbp XhoI fragment of pMAR4 did not. Recombinant plasmid pMAR430, which contained a 3-kbp PstI fragment of pMAR4, also transformed LM(TK−) cells to TK+. The results strongly suggest that the coding region of the MarHV TK gene was within a 2.4-kbp pMAR4 sequence extending from the PstI (0.33 kbp) to the EcoRI (2.7 kbp) cleavage sites.

Virology, 1981

ABSTRACT Recombinant plasmid pAGO codes for herpes simplex virus type 1 (HSV-1) thymidine kinase ... more ABSTRACT Recombinant plasmid pAGO codes for herpes simplex virus type 1 (HSV-1) thymidine kinase (TK) and consists of a 2-kbp HSV-1 DNA fragment inserted at the unique PvuII cleavage site of plasmid pBR322. A hybrid plasmid, designated pMH110, has been derived from plasmid pAGO by deleting the 1689-bp pBR322 nucleotide sequence of pAGO, which extends from the BamHI to the PvuII cleavage site, and the 250-bp HSV-1 nucleotide sequence of pAGO, which extends from the PvuII to the BglII cleavage site. Plasmid pMH110 biochemically transformed LM(TK−)cells to the TK+ phenotype. The biochemically transformed cell lines had the following properties: (i) they were resistant to the growth-inhibiting effects of 1 mM thymidine; and (ii) they expressed an HSV-1-specific TK activity. This HSV-1 TK activity was purified after labeling biochemically transformed cell lines [LM(TK−)/TF pMH110 E2 and LM(TK−)/TF pMH110 Hc2] with [35S]methionine. Immunoprecipitation experiments revealed that the TK polypeptides made in the biochemically transformed cells had molecular weights of about 39,000 to 40,000, which are about the same as the molecular weights of the TK polypeptides previously purified from HSV-1-infected LM(TK−) cells and other biochemically transformed cell lines. The experiments support the hypothesis that the functional coding region of the HSV-1 TK gene is 3′ to the BglII cleavage site, and they also suggest that the HSV-1 TK messenger RNA may have been initiated in cells transformed by HincII- and EcoRI-cleaved pMH110 DNA at a site in cellular (or plasmid) DNA upstream from the HSV-1 DNA BglII cleavage site.

Sexually Transmitted Diseases, 1983

Proceedings of the National Academy of Sciences, 1981

Herpes simplex virus thymidine kinase activity of thymidine kinase-deficient Escherichia coli K-1... more Herpes simplex virus thymidine kinase activity of thymidine kinase-deficient Escherichia coli K-12 mutant transformed by hybrid plasmids (thymidine kinase-deficient mouse L cells/biochemical transformation/anti-herpes simplex virus type 1 IgG)

Phytotherapy Research, 2002

The virostatic activity of sophocarpines and gancyclovir (GCV) was tested using HHV-6 Z29 strain ... more The virostatic activity of sophocarpines and gancyclovir (GCV) was tested using HHV-6 Z29 strain and Molt-3 cells. The cytotoxic (IC(50)) and the antiviral (ED(50)) values were first experimentally determined and selective indices (SI) were then calculated. The SI values for sophocarpines 1 and 2 and GCV were in the order 184, 183, and 23, respectively. Though preliminary, these findings indicate that sophocarpines have the potential to inhibit HHV-6 replication.

Nucleic Acids Research, 1980

The thymidine kinase (TK) gene of HSV-1 has been cloned in Escherichia coli K12 plasmids, pMHl, p... more The thymidine kinase (TK) gene of HSV-1 has been cloned in Escherichia coli K12 plasmids, pMHl, pMHlA, and pMH4. These plasmids contain a 1,920bp HSV-1 TK DNA sequence, which replaces a 2,067 bp EcoR I to Pvu II sequence of plasmid pBR322 DNA. Superhelical DNAs of plasmids pMHl, pMHlA, and pMH4 as well as plasmid DNAs cleaved by EcoR I, Hinc II, Bgl II, Sma I, and Pvu II transformed TK-deficient LM(TK-) cells to the TKe phenotype. A 1,230bp EcoR I-Sma I fragment purified from pMHl DNA (and from plasmid pAGO DNA, the parent of pMH1) also transformed LM(TKI) cells. Serological and disc PAGE studies demonstrated that the TK activity expressed in biochemically transformed cells was HSV-l-specific. The experiments suggest that the HSV-1 TK coding region may be contained within a l.lkbp DNA sequence extending from about the Hinc II (or Bgl II) cleavage site to the Sma I site. 35S-methionine labeling experiments carried out on cell lines transformed by Hinc II-cleaved pMHl DNA and by the EcoR I-Sma I fragment showed that the TKs purified from the transformed cells consisted of about 39-40,000 dalton polypeptides.

Journal of Medical Virology, 1983

Marmoset herpesvirus (MarHV) deletion mutants in the thymidine kinase (TK) gene were isolated aft... more Marmoset herpesvirus (MarHV) deletion mutants in the thymidine kinase (TK) gene were isolated after infection of OMK cells with TK+ MarHV DNA and the hybrid plasmid, pMAR401, which lacks a 2.6-kb KpnI-M fragment in the coding region of the MarHV TK gene. After plaque purification in TK-HeLa(BU25) cells, the DNA's from five recombinant araT-resistant MarHV clones were analyzed with restriction nucleases to verify that the 2.6-kb KpnI-M fragment (and a 0.9-kb BglII-Q fragment) were deleted from the viral DNA's. Molecular hybridization experiments using "P-labeled pMAR4 probes and viral DNA fragments also showcd that the recombinant viral DNA's lacked the KpnI-M and BglII-Q fragments, that BamHI-I of parental virus was shortened, and that three new HindIII fragments replaced the parental virus HindIII-G fragment. The recombinants did not induce TK activity in LM (TK-) cells. To study the relative virulence of the recombinants, 3-week-old Swiss mice were injected intracerebrally (Ic) or subcutaneously (Sc) in the sacro-lumbar region with either parental or recombinant viruses. The LD50 for the parental virus was 3 p.f.u. (Ic) and 7,600 p.f.u. (Sc). The recombinant viruses were significantly less virulent than TK+ MarHV after Ic inoculation (LD50 of 62,000 and 32,000 p.f.u., respectively, for viruses 5D-6B and 5D-4B) and gave no fatalities after Sc inoculation. Mice surviving TK-MarHV infections were protected from challenge with TK+ parental MarHV. Recombinant TK-MarHV's may be useful as vectors for the expression of foreign genes in animal cells and as the starting material for the design of vaccines.

Journal of Medical Virology, 1994

Intervirology, 1980

Although the size of marmoset herpesvirus (MarHV) DNA, estimated by velocity sedimentation in suc... more Although the size of marmoset herpesvirus (MarHV) DNA, estimated by velocity sedimentation in sucrose gradients, was similar to that of herpes simplex virus type 1 (HSV-1) DNA, the restriction endonuclease sites of MarHV and HSV-1 DNAs were quite different. A specific BamHI restriction fragment (6.2 x 10(6) daltons) of MarHV DNA biochemically transformed LM(TK-) mouse fibroblasts to the thymidine kinase(TK)-positive phenotype. Rabbit antisera, prepared against MarHV TK, inhibited MarHV-induced TK, but not HSV-1, HSV-2, or cellular TKs. Disc PAGE analyses and enzyme neutralization experiments with the anti-MarHV TK sera demonstrated that the TK expressed in MarHV transformants was MarHV-specific.

International Journal of Cancer, 1981

Sex Transm Dis, Mar 31, 1983

In vivo (Athens, Greece)

Central European journal of public health

Investigative ophthalmology & visual science, 1987

In vivo (Athens, Greece)

Investigative ophthalmology & visual science, 1995

European journal of cancer & clinical oncology, 1982

Virology, Jan 15, 1983

Virology, 1980

Virology, 1981

Sexually Transmitted Diseases, 1983

Proceedings of the National Academy of Sciences, 1981

Phytotherapy Research, 2002

Nucleic Acids Research, 1980

Journal of Medical Virology, 1983

Journal of Medical Virology, 1994

Intervirology, 1980

International Journal of Cancer, 1981