PubMed Health⌕ Search

Biomedical subjects

A M Arvin

Publications and source records attributed to A M Arvin.

At least 19 recordsLinked to original sources
PubMed1992

Identification of women at unsuspected risk of primary infection with herpes simplex virus type 2 during pregnancy.

BACKGROUND: Primary infections with herpes simplex virus type 2 (HSV-2) acquired by women during pregnancy account for about half of the morbidity and mortality from HSV-2 among neonates. The other half results from reactivation of old infections. Better methods are needed to identify which women are at risk for primary HSV-2 infection. METHODS: We prospectively studied HSV-2 infections among pregnant women who were patients in private obstetrical practices. Using an enzyme-linked immunosorbent assay that detects type-specific antibodies to HSV-2 glycoprotein G, we determined the prevalence at base line of HSV-2 infections among pregnant women and their husbands, the frequency of discordance for infection between partners, and the risk of seroconversion during pregnancy among the seronegative women whose husbands were seropositive. RESULTS: The seroprevalence of HSV-2 was 32 percent among the 277 women followed throughout their pregnancies and 25 percent among the 190 husbands studied. Two thirds of the HSV-2-seropositive women had no history of genital herpes. Of the 190 couples, 139 (73 percent) were serologically concordant for HSV-2 antibodies (57 percent being seronegative and 16 percent being seropositive), whereas 51 couples (27 percent) were discordant, despite having been sexually intimate for a mean of 6.1 years. Eighteen women who were seronegative for HSV-2 (9.5 percent) had seropositive partners, of whom 10 (56 percent) had no history of genital herpes. Thus, approximately 5 percent of these pregnant women had an unsuspected risk of contracting a primary HSV-2 infection. One of the 18 seronegative women with a seropositive husband seroconverted to HSV-2 during pregnancy; none of the other women seroconverted. CONCLUSIONS: In this study about 10 percent of pregnant women were at risk of contracting a primary HSV-2 infection from their HSV-2-seropositive husbands. In addition, about a third of these women were seropositive for HSV-2 and thus at risk for asymptomatic, reactivated infections. Serologic testing of couples can identify women who are at risk for primary or reactivated HSV-2 infections during pregnancy.

Antibodies, Viral↗
PubMed1992

The management of pregnancies complicated by genital infections with herpes simplex virus.

In this review we summarize current knowledge related to the identification of pregnancies that may be complicated by genital herpes and describe the consequences of maternal infections with genital herpes. We address the implications of this information for the management of genital herpes during pregnancy and at delivery and for the care of neonates exposed to herpes simplex virus at delivery. On the basis of the current data, we cannot make specific recommendations concerning many of the clinical problems that are caused by herpes simplex virus infections in pregnant women. We identify and discuss unresolved questions about optimal management.

Female↗
PubMed1992

Subclinical varicella-zoster virus viremia, herpes zoster, and T lymphocyte immunity to varicella-zoster viral antigens after bone marrow transplantation.

Bone marrow transplant (BMT) recipients were evaluated for subclinical varicella-zoster virus (VZV) viremia and symptoms of herpes zoster after transplantation. Viremia was demonstrated by testing peripheral blood mononuclear cells using polymerase chain reaction and was documented in 19% of 37 patients. When reactivation was defined as herpes zoster and/or subclinical VZV viremia, 41% of VZV-seropositive BMT recipients experienced VZV reactivation. None of 12 patients tested before VZV reactivation had T lymphocyte proliferation to VZV antigen (mean stimulation index, 1.0 +/- 0.42 [SD] at less than 100 days; 12.0 +/- 6.03 at greater than 100 days [P = .003]). Among patients tested at greater than 100 days, 5 (63%) of 8 with detectable T cell proliferation had subclinical or clinical VZV reactivation compared with none of 6 who lacked VZV T cell responses. Recovery of VZV-specific cytotoxic T lymphocyte function was observed in 50% of BMT patients, but BMT recipients had significantly fewer circulating cytotoxic T lymphocytes that recognized VZV immediate early protein (P = .03) or glycoprotein I (P = .004) than did healthy VZV immune subjects. In vivo reexposure to VZV antigens due to subclinical VZV viremia or symptomatic VZV reactivation may explain the recovery of virus-specific T cell immunity after BMT.

Adolescent↗
PubMed1992

Kinetics and viral protein specificity of the cytotoxic T lymphocyte response in healthy adults immunized with live attenuated varicella vaccine.

The cytotoxic T lymphocyte (CTL) response was evaluated in adults given live attenuated varicella vaccine, using target cells expressing varicella-zoster virus (VZV) immediate-early protein (IE62) or VZV glycoproteins gpI, gpIV, or gpV to determine viral protein specificity. The frequency of CTL that recognized IE62 was 1:171,000 +/- 46,000 SE in subjects tested 10 days to 8 weeks after the initial vaccine dose; the induction of CTL specific for gpI was equivalent. CTL recognition of VZV proteins was mediated by CD4+ or CD8+ cells. CTL recognition of IE62 and gpIV persisted in vaccinees (tested approximately 4 years later) and was comparable to that in the naturally immune. The mean frequency of CTL specific for gpV was lower (but not significantly) in vaccinees than in naturally immune subjects. Assay of responder cell frequencies showed persistence of equivalent numbers of T lymphocytes that recognized IE62 and gpI in vaccinees and naturally immune subjects. Immunization with this vaccine elicited memory T lymphocyte responses to VZV comparable to those induced by natural infection.

Antibodies, Viral↗
PubMed1992

Cell-mediated immunity to varicella-zoster virus.

Natural varicella-zoster virus (VZV) infection and immunization with live attenuated varicella vaccine elicits T lymphocytes that recognize VZV glycoproteins, gpI-V, and the immediate early/tegument protein, the product of gene 62 (IE62). Proliferation or cytotoxicity assays, done under limiting dilution conditions to estimate responder cell frequencies, indicate no preferential recognition of VZV proteins by human T cells. Analysis of the primary cytotoxic T lymphocyte (CTL) response after vaccination demonstrates that both gpI and IE62 are targets of the early response. CD4(+)- and CD8(+)-mediated CTL recognition of these viral proteins can be detected with natural and vaccine-induced immunity. Responder cell frequencies for protein-specific T cell proliferation and CTL function are generally comparable in subjects with natural and vaccine-acquired immunity to VZV. Exogenous reexposure to VZV results in enhanced T cell proliferation and may be an important mechanism for maintaining virus-specific cellular immunity. Providing exogenous reexposure by giving varicella vaccine to individuals who have preexisting natural immunity markedly increases the responder cell frequencies of T cells that proliferate in response to VZV antigen and the numbers of circulating CTL that recognize VZV proteins.

Antigens, Viral↗
PubMed1992

Immunity in strain 2 guinea-pigs inoculated with vaccinia virus recombinants expressing varicella-zoster virus glycoproteins I, IV, V or the protein product of the immediate early gene 62.

The immunogenicity of specific varicella-zoster virus (VZV) proteins, with emphasis upon cell-mediated immune responses, was evaluated by immunizing strain 2 guinea-pigs with vaccinia virus recombinants that express gpI (vac-gpI), gpIV (vac-gpIV) and gpV (vac-gpV) or the IE-62 protein (vac-IE-62). Vac-gpI elicited the highest initial mean T cell proliferation response [stimulation index (S.I.) 3.8 +/- 0.9 S.E.M.] whereas inoculation with vac-gpV produced the lowest primary T cell response (S.I. 2.5 +/- 1.1 S.E.M.). T cell proliferation was detected for a shorter period after immunization with vac-gpV compared to vac-gpI, vac-gpIV or vac-IE-62. A comparison of the immunogenicity of vac-gpI and vac-IE-62 with the same proteins prepared by immunoaffinity purification showed that immunization with these proteins in either form elicited virus-specific IgG antibodies and T cell recognition. The presence or absence of IgG antibodies to the IE-62 protein was used to assess protection against challenge with guinea-pig cell-adapted infectious VZV in animals that had been inoculated with vac-gpI, vac-gpIV or vac-gpV. Immunization with vac-gpI and vac-gpIV restricted VZV replication but all animals given vac-gpV developed antibodies to IE-62 after challenge with infectious VZV. Priming of the T lymphocyte response was observed in all animals immunized with VZV-vaccinia virus recombinants after subsequent exposure to infectious VZV. These experiments with VZV vac-gpI, vac-gpIV and vac-gpV in guinea-pigs suggest variability in the capacity of herpesviral glycoproteins to elicit cell-mediated immunity in vivo. Induction of virus-specific immunity using IE-62 means that this major tegument protein of VZV could be a useful component for vaccine development.

Animals↗
PubMed1992

Outbreak of ceftazidime resistance due to a novel extended-spectrum beta-lactamase in isolates from cancer patients.

Ceftazidime is widely used in the therapy of infectious complications in neutropenic patients. We studied an outbreak of ceftazidime-resistant gram-negative bacillary infections in pediatric cancer patients receiving empirical ceftazidime therapy for neutropenic fever. Fourteen isolates (12 Klebsiella pneumoniae and 2 Escherichia coli) from 13 patients were studied. Specimens were obtained from multiple clinical sites including blood, urine, throat, and lung. The organisms were resistant to ceftazidime, aztreonam, and penicillins but remained susceptible to cephamycins and imipenem. All resistant isolates produced a novel beta-lactamase (TEM-26) with a pI of approximately 5.58, which was transferred by transformation to E. coli on a 7.9-kb nonconjugative plasmid which cotransferred resistance to trimethoprim-sulfamethoxazole. This enzyme readily hydrolyzed ceftazidime, aztreonam, and penicillins in a spectrophotometric assay. DNA sequencing data suggest that TEM-26 is derived from TEM-1.

Bacteria↗
PubMed1992

The varicella-zoster virus immediate-early protein IE62 is a major component of virus particles.

Varicella-zoster virus (VZV) open reading frame (ORF) 62 potentially encodes a protein with considerable amino acid homology to the herpes simplex virus (HSV) immediate-early regulatory polypeptide ICP4 (or IE3). To identify and characterize its protein product(s) (IE62), we used a rabbit antiserum prepared against a synthetic peptide corresponding to the C-terminal 13 amino acids of the predicted protein. This antiserum reacted with phosphorylated polypeptides of 175 to 180 kDa that were made in VZV-infected cells and in cells infected with a vaccinia virus recombinant expressing IE62, but not in control-infected cells, confirming its specificity and reactivity to the IE62 protein. The antiserum recognized a 175-kDa polypeptide in purified virions that comigrated with a major structural protein. Comparison of this reactivity with that of an antipeptide antiserum directed against the VZV ORF 10 product (homologous to the HSV major structural protein VP16) indicates similar levels of ORF 62 and ORF 10 polypeptides in VZV virions. In contrast, antipeptide antiserum directed against the VZV ORF 29 product, the homolog of the HSV major DNA-binding protein, failed to recognize any protein in our virion preparations. Treatment of virions with detergents that disrupt the virion envelope did not dissociate IE62 from the nucleocapsid-tegument structure of the virion. Differential sensitivity of VZV virion IE62 to trypsin digestion in the presence or absence of Triton X-100 indicates that IE62 is protected from trypsin degradation by the virus envelope; since it is not a nucleocapsid protein, we conclude that it is part of the tegument. Finally, we show that the virion 175-kDa protein either can autophosphorylate or is a major substrate in vitro for virion-associated protein kinase activity.

Adenosine Triphosphate↗
PubMed1991

A controlled trial of acyclovir for chickenpox in normal children.

BACKGROUND: Chickenpox, the primary infection caused by the varicella-zoster virus, affects more than 3 million children a year in the United States. Although usually self-limited, chickenpox can cause prolonged discomfort and is associated with infrequent but serious complications. METHODS: To evaluate the effectiveness of acyclovir for the treatment of chickenpox, we conducted a multicenter, double-blind, placebo-controlled study involving 815 healthy children 2 to 12 years old who contracted chickenpox. Treatment with acyclovir was begun within the first 24 hours of rash and was administered by the oral route in a dose of 20 mg per kilogram of body weight four times daily for five days. RESULTS: The children treated with acyclovir had fewer varicella lesions than those given placebo (mean number, 294 vs 347; P less than 0.001), and a smaller proportion of them had more than 500 lesions (21 percent, as compared with 38 percent with placebo; P less than 0.001). In over 95 percent of the recipients of acyclovir no new lesions formed after day 3, whereas new lesions were forming in 20 percent of the placebo recipients on day 6 or later. The recipients of acyclovir also had accelerated progression to the crusted and healed stages, less itching, and fewer residual lesions after 28 days. In the children treated with acyclovir the duration of fever and constitutional symptoms was limited to three to four days, whereas in 20 percent of the children given placebo illness lasted more than four days. There was no significant difference between groups in the distribution of 11 disease complications (10 bacterial skin infections and 1 case of transient cerebellar ataxia). Acyclovir was well tolerated, and there was no significant difference between groups in the titers of antibodies against varicella-zoster virus. CONCLUSIONS: Acyclovir is a safe treatment that reduces the duration and severity of chickenpox in normal children when therapy is initiated during the first 24 hours of rash. Whether treatment with acyclovir can reduce the rare, serious complications of chickenpox remains uncertain.

Acyclovir↗
PubMed1991

Equivalent recognition of a varicella-zoster virus immediate early protein (IE62) and glycoprotein I by cytotoxic T lymphocytes of either CD4+ or CD8+ phenotype.

Immunity to varicella-zoster virus (VZV), a member of the alpha-herpes virus family, exemplifies the host response to an ubiquitous human viral pathogen. In this investigation of the cytotoxic T lymphocyte (CTL) response to VZV, the depletion of CD4+ T lymphocytes made it possible to demonstrate CD8(+)-mediated cytotoxic function against autologous VZV-infected lymphoblastoid cells targets. CTL recognition of two major VZV proteins, the immediate early protein (IE62) and gp I, was demonstrated in limiting dilution cultures of T lymphocytes obtained from immune donors, stimulated with inactivated VZV Ag, and tested against lymphoblastoid cells infected with vaccinia recombinants expressing these VZV proteins. Among 11 VZV donors tested at least 20 y after primary infection, the mean precursor frequency for T lymphocytes that recognized the IE62 protein was 1:105,000 +/- 85,000 SD, with a range of 1:13,000 to 1:231,000. The mean frequency of CTL precursors specific for gp I in 11 subjects was equivalent, with a mean of 1:121,000 +/- 86,000 SD (range 1:15,000 to 1:228,000) (p = 0.68). Limiting dilution cultures were also prepared using purified CD4+ or CD8+ T lymphocyte populations recovered from PBMC by sterile fluorescence-activated cell sorting. CTL precursors that recognized the IE62 protein or gp I were derived from each of the major T lymphocyte populations by stimulation with inactivated VZV Ag; CD4+ and CD8+ CTL precursor frequencies for the IE62 protein and gp I were equivalent (p = 0.2). We conclude that antiviral CTL activity against targets expressing VZV proteins was mediated equally well by T lymphocytes of the CD4+ or CD8+ phenotype and that antiviral CTL function could be elicited in each subpopulation by exposure to non-infectious viral Ag.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1991

Pharmacokinetics of acyclovir in the term human pregnancy and neonate.

Concern about neonatal herpes often leads to cesarean delivery of infants in women with a history of genital herpes. The antiviral drug acyclovir has been used effectively to suppress genital herpes simplex virus recurrences in nonpregnant adults. Its administration to pregnant women with recurrent genital herpes may reduce herpes simplex virus recurrences and thus may decrease the cesarean section rate among this population. To study the pharmacokinetics, safety, and patient tolerance of suppressive oral acyclovir, either 200 mg (n = 7) or 400 mg (n = 8) was administered orally every 8 hours to pregnant women with a history of recurrent herpes simplex virus, from 38 weeks' gestation until delivery. The mean +/- SD plasma levels for the 200 and 400 mg groups, respectively, were: first dose peak, 1.7 +/- 0.6 and 2.3 +/- 1.0 mumol/L; steady-state trough, 0.7 +/- 0.3 and 0.8 +/- 0.6 mumol/L; steady-state peak, 1.9 +/- 1.0 and 3.3 +/- 1.0 mumol/L. In late gestation maternal acyclovir pharmacokinetics were similar to those of nonpregnant adults from other studies. Acyclovir was concentrated in the amniotic fluid; however, there was no accumulation in the fetus (mean maternal/infant plasma ratio at delivery was 1.3). Acyclovir was well tolerated, and no toxicity was seen in the mothers or infants. The administration of acyclovir, 400 mg every 8 hours, appears appropriate for use in an efficacy and safety study regarding suppression of herpes simplex virus recurrences during the last weeks of pregnancy.

Acyclovir↗
PubMed1991

Human T cells recognize multiple epitopes of an immediate early/tegument protein (IE62) and glycoprotein I of varicella zoster virus.

Infection with varicella zoster virus (VZV) elicits persistent cell-mediated immunity directed against the immediate early (IE62) protein and the glycoprotein I (gp I) in most healthy subjects. In these experiments, synthetic peptides corresponding to residues of the IE62 protein and gp I were used to identify linear amino acid sequences of these immunogenic VZV proteins that were recognized by peripheral blood T lymphocytes from VZV-immune individuals of known major histocompatibility complex (MHC) type. All of 12 VZV-immune donors had T-cell proliferative responses, defined as a stimulation index (SI) greater than or equal to 2.0, to at least two of ten synthetic IE62 peptides; the mean number of IE62 peptides recognized by T cells from VZV-immune donors was seven. Five of the ten IE62 peptides stimulated T cells from 75% to 83% of the VZV-immune donors; the other five IE62 peptides were recognized by T cells from 42% to 67% of the subjects. All VZV-immune donors also had T proliferation responses to at least two of ten synthetic gp I peptides; the mean number of peptides recognized was six. Six of the ten gp I peptides were recognized by T cells from 67% to 92% of the VZV-immune donors; the frequency of donors responding to the other gp I peptides ranged from 42% to 58%. None of five nonimmune donors demonstrated T-cell proliferation to any of the IE62 or gp I peptides. A combination of two IE62 peptides provided epitopes that could be recognized by T cells from all twelve VZV-immune donors, regardless of DR type. Similarly, one gp I peptide in combination with either of two other gp I peptides induced proliferation of T cells from all immune subjects. Memory T cells with specificity for multiple short amino acid sequences of the IE62 protein and gp I were detected in subjects who had had primary VZV infection more than 20 years earlier. These observations indicate that natural VZV infection elicits a diverse cell-mediated immune response to viral proteins that is not restricted to only one or two immunodominant regions. Although the usefulness of peptide vaccines remains to be established, multiple epitopes of the IE62 protein and gp I were identified that could be presented by antigen-presenting cells (APC) and recognized by T cells from most subjects in an "outbred" human population.

Amino Acid Sequence↗
PubMed1991

Investigation of varicella-zoster virus infection by polymerase chain reaction in the immunocompetent host with acute varicella.

A polymerase chain reaction (PCR) method developed to detect varicella zoster virus (VZV) in clinical samples is based on amplifying sequences of viral gene 31, the coding region for glycoprotein II. Its sensitivity was evaluated by amplification from plasmid VZV DNA containing VZV gene 31; 45 copies were detected in 1 microgram of human DNA. In testing within 24 h after the onset of varicella exanthem, 21 (75%) of 28 lesion samples were positive by VZV PCR, whereas VZV was isolated from only 21% by a standard tissue culture method. Only 1 (3.3%) of 30 samples of oropharyngeal secretions but peripheral blood mononuclear cells from 8 (67%) of 12 patients were positive. The sensitivity and specificity of the VZV PCR method indicates its usefulness for investigating the pathogenesis of VZV infection. Direct contact with cutaneous lesions rather than respiratory secretions may be the most important route of VZV transmission from healthy individuals with acute varicella.

Acute Disease↗
PubMed1991

Major histocompatibility complex restriction of T-cell responses to varicella-zoster virus in guinea pigs.

Varicella-zoster virus (VZV), adapted to grow in guinea pig fibroblasts, was injected subcutaneously into Hartley, strain 2, and strain 13 guinea pigs. Serum immunoglobulin G antibodies were detected 2 weeks later, and T-cell proliferative responses by blood lymphocytes were found 3 weeks after injection. The proliferating cells bound the 155 antibody, which defines a CD4-like subset of guinea pig T lymphocytes. VZV-infected fibroblasts of human, Hartley, and strain 13 origin elicited equivalent amounts of proliferation, which was quantitatively greater than that obtained with an extracted VZV antigen. Uninfected (control) human or guinea pig fibroblasts did not elicit T-cell proliferation. The proliferative response to VZV required the presence of autologous (strain 2 or 13) antigen-presenting cells and was blocked by the addition of an anti-class II major histocompatibility complex antibody. Effector cells obtained from in vitro cultures mediated class II-restricted cytotoxicity to L2C cells incubated with VZV. Class I-restricted responses were obtained only by cross-priming strain 2 animals with strain 13 peritoneal exudate cells which had been preincubated with VZV. The data indicate that guinea pigs resemble humans in that class II-restricted T cells with specificity for VZV are more readily cultured from blood than are class I-restricted cells.

Animals↗
PubMed1991

Lack of transmission of the live attenuated varicella vaccine virus to immunocompromised children after immunization of their siblings.

The safety of administering the live attenuated Oka/Merck varicella vaccine to the well siblings of children with malignancy was evaluated as a strategy for reducing the risk of household exposure to varicella among immunocompromised children. Susceptible well children were eligible for vaccination if the child with malignancy had leukemia, lymphoma, or solid tumor in remission for 3 months or longer. No evidence of vaccine virus transmission was found among 30 children with malignancy whose 37 healthy susceptible siblings were immunized with varicella vaccine. Varicella-zoster virus was not isolated from the oropharyngeal secretions taken from 17 vaccinees or their 14 immunocompromised siblings. None of the 30 immunocompromised children had vaccine-related rashes or showed immunologic evidence of subclinical varicella-zoster virus infection based on testing for varicella-zoster virus IgG antibodies and T-lymphocyte proliferation to varicella-zoster virus. Four healthy vaccinees eventually had mild breakthrough cases of varicella, with transmission to the high-risk sibling in 3 cases. However, even in these families, the immunocompromised children had been protected from household exposure varicella for at least 20 months early in the course of their immunosuppressive treatment.

Adolescent↗