Search PubMed⌕ Search

Biomedical subjects

D A Baker

Publications and source records attributed to D A Baker.

At least 91 records · Page 5Linked to original sources
PubMed1989

Clinical evaluation of a new herpes simplex virus ELISA: a rapid diagnostic test for herpes simplex virus.

A new sensitive and rapid enzyme-linked immunosorbent assay (ELISA) test (Du Pont HERPCHEK) for the detection of herpes simplex virus (HSV) antigen was evaluated. A total of 563 clinical samples collected from patients attending obstetrics and gynecology and sexually transmitted disease clinics in two geographic locations were tested by ELISA, and the results were compared with virus isolation in cell culture. The sensitivity and specificity of the ELISA were 97.5 and 98.6%, respectively. When a confirmatory blocking ELISA was used to demonstrate the presence of HSV antigen in culture-negative but ELISA-positive samples, the specificity of the assay increased to 100%. The assay is easy to perform and may be used to diagnose HSV infection rapidly without the need for culture confirmation.

Adult↗
PubMed1989

One-year suppression of frequent recurrences of genital herpes with oral acyclovir.

A double-blind, placebo-controlled study was undertaken to evaluate the long-term efficacy and safety of oral acyclovir suppressive therapy over a 1-year period. Results from the multicenter trials, based on a total of 261 patients with frequently recurring genital herpes, were analyzed. Of the patients enrolled in the study, 131 received oral acyclovir capsules (800 mg) daily and 130 received placebo capsules. Medication was taken twice daily. Analysis of data from patients who completed a full year of therapy demonstrated that only 5% of patients receiving placebo were free from recurrences, as compared with 46% of acyclovir recipients. The mean number of recurrences for patients on acyclovir therapy was 1.8, as compared with a rate of 8.7 recurrences for the placebo group over the course of the year. The mean time to the first recurrent herpes outbreaks was 19 days for the placebo group and 274 days for the acyclovir-treated patients. There were no significant differences between the two groups in laboratory data or in the frequency or nature of side effects reported. Daily administration of acyclovir capsules for 1 year is a safe and effective therapy for control of frequent recurrences of genital herpes.

Acyclovir↗
PubMed1989

Acyclovir therapy during pregnancy.

Although there are as yet no established indications for acyclovir use in pregnancy, the most reasonable uses are for maternal infections such as disseminated herpes simplex, varicella pneumonia, and severe primary genital herpes. Other potential, but more problematic, uses during pregnancy are for uncomplicated primary genital herpes infections, maternal varicella, and for prophylaxis against the recurrence of genital herpes near term. We review each of these potential uses and the pharmacokinetics of acyclovir in pregnancy while emphasizing that at the present time, safety, efficacy, and appropriate dosage of the drug have not been established for any use in pregnancy.

Acyclovir↗
PubMed1988

Segmented alpha-helical coiled-coil structure of the protein giardin from the Giardia cytoskeleton.

The parasitic flagellate Giardia is the source of a filamentous protein, giardin, which binds to microtubules. The primary sequence of one giardin chain has been decoded from the base sequences of cDNAs isolated by antibody screens of a library constructed in the expression vector lambda gt11. The amino acid sequence favours a continuous alpha-helical fold for the protein without any inserts of a non-helical character. Analysis of apolar residue positions revealed 35 repeating heptads consistent with coiled-coil structure. This conformation relates giardin to the alpha-type fibrous proteins (k-m-e-f class) like tropomyosin and myosin (also found in Giardia). The giardin sequence has a regular series of skip residues like those at certain positions in the rod section of nematode myosin where the internal apolar seam of the coiled coil is shifted on the helix surface. The skips divide the giardin coil into quasi-equivalent structural segments about 4 nm in length, which might be domains for combining with tubulin subunits in the microtubule surface lattice.

Amino Acid Sequence↗
PubMed1988

Suppression of newborn natural killer cell activity by prostaglandin E2.

The effect of prostaglandin E2 on natural killer cell activity of cord blood was examined. Natural killer cell activity, determined by chromium 51 release, was significantly reduced after prostaglandin E2 (1 microgram/ml) treatment. Prostaglandin E2 has been found to enhance the cellular spread of herpesvirus. Thus prostaglandins may enhance viral infections indirectly by suppressing natural killer cell activity.

Acyclovir↗
PubMed1987

Maternal rubella at St Thomas' Hospital in 1978 and 1986: support for augmenting the rubella vaccination programme.

The effects of the rubella epidemics in 1978 and 1986 among patients attending antenatal clinics at St Thomas' Hospital were compared. Although many pregnant women who had been exposed to rubella-like illnesses were investigated in both 1978 (269) and 1986 (160), the number of cases of maternal rubella was substantially lower in 1986 (1) than in 1978 (17). Rubella vaccination of 11-14-year-old girls was introduced in the United Kingdom in 1970, but 10% of our patients were susceptible and only 36% gave a definite history of vaccination. Despite the smaller number of maternal rubella cases, substantial resources were expended on assessing patients who had been exposed to or who presented with rubella-like illnesses. In 1978 an intensification of the selective rubella vaccination campaign was recommended, but experience in the 1986 epidemic supports the view that the programme should be augmented by vaccination of preschool children with a combined measles, mumps, and rubella vaccine, with a view to rubella eradication.

Adolescent↗
PubMed1987

Enhancement of maternal and neonatal natural killer cell activity with interleukin-2.

Natural killer cell activity, which is vital to the immune surveillance against viruses and tumor cells, is significantly lower in the newborn infant than in the mother. Incubation of maternal and cord blood lymphocytes with interleukin-2 significantly increases natural killer activity in both. The increase is substantially greater in the cord blood lymphocytes.

Female↗
PubMed1987

Lymphocyte subsets in the neonates of preeclamptic mothers.

With the aid of specific monoclonal antibodies, indirect immunofluorescence, and flow cytometry, peripheral blood lymphocyte populations were studied in 12 preeclamptic mothers and compared with those of ten normal patients at term. As well, lymphocyte subsets from newborns of these preeclamptic mothers and ten normal patients at term were studied. Lymphocytes were labelled with murine monoclonal antibodies directed against T cells and subsets of helper cells, suppressor/cytotoxic cells and natural killer cells. Cord blood lymphocytes of neonates from preeclamptic mothers showed a statistically significant reduction of total T cells, helper cells, and natural killer cells as compared to control. A significant reduction in helper/suppressor ratio was also observed. It is hypothesized that the differences in the immune system of the neonates in the preeclamptic group may be due to the stress of intrauterine malnutrition secondary to uteroplacental insufficiency.

Female↗
PubMed1987

A rapid colorimetric AFP monoclonal antibody test for the diagnosis of preterm rupture of the membranes.

Premature rupture of the membranes is a common and serious complication of pregnancy. Despite the prevalence and severity of sequelae, current diagnostic techniques are less than ideal. We studied 48 women with preterm rupture of the membranes with a rapid, colorimetric monoclonal alpha-fetoprotein (AFP) antibody test. Sensitivity was 98% for AFP testing compared to 77% for nitrazine and 62% for ferning. The differences in sensitivity were greater when membranes were ruptured for longer than 12 hours. In all 31 patients without rupture of the membranes, AFP testing was negative. Neither urine nor semen affected AFP testing, whereas blood did. Alpha-fetoprotein testing may be a significant addition to current methods in the diagnosis of preterm rupture of the membranes.

Amniotic Fluid↗
PubMed1986

Failure of ibuprofen in treatment of herpes genitalis.

Motrin (ibuprofen), a potent inhibitor of prostaglandin synthetase, was tested in women and men for treatment of recurrences of genital herpes. In a double-blind trial, no statistically significant differences were observed between treated and placebo groups in any of the measured parameters.

Adult↗
PubMed1986

Acyclovir for genital herpes simplex virus infections. A review.

Genital herpes simplex virus (HSV) causes a common and debilitating infection seen by the gynecologist and obstetrician. Over the last decade this disease has become nearly an epidemic in the United States. A recent, major advance in antiviral chemotherapy, acyclovir, allows safe, effective treatment and suppression of HSV infection.

Acyclovir↗
PubMed1985

The effect of prostaglandin E2 on the initial immune response to herpes simplex virus infection.

Numerous clinical situations, demonstrated to be associated with reactivation of herpes simplex virus infections, have also been shown to produce increases in local levels of prostaglandins. The current study was initiated to determine if prostaglandins play a role in the immune response and control of herpes simplex virus infections. Lymphocytes from volunteers were stimulated with concanavalin A, herpes simplex virus 1, or herpes simplex virus 2 in the presence of prostaglandin E2 or ibuprofen, and the lymphocytes served as their own controls. The data suggest a statistically significant suppression in nonspecific T cell mitogen stimulation (concanavalin A), as well as specific herpes simplex virus 1 and 2 stimulations as measured by tritiated thymidine uptake by lymphocytes when stimulated in the presence of prostaglandin E2. Ibuprofen did not alter the proliferative response to concanavalin A, herpes simplex virus 1, or herpes simplex virus 2 stimulation. This report examines the involvement of prostaglandins in herpesvirus infection such as the suppression of T cell function, allowing for a clinical recurrence. The usefulness of nonsteroidal antiinflammatory agents in the therapy of herpes simplex virus infections is also discussed.

Adolescent↗
PubMed1985

Lymphocyte subsets in women on low dose oral contraceptives.

Oral contraceptive users have been reported to have a higher incidence of viral, bacterial and fungal infections. This study was undertaken to try to elucidate some of the mechanisms responsible for this increased susceptibility to infection. Peripheral blood lymphocytes were labelled with murine monoclonal antibodies directed against T cells and the various lymphocyte subsets: helper cells, suppressor/cytotoxic cells, or natural killer cells. The lymphocytes were then analyzed on a Coulter Electronics Epics V fluorescent activated cell sorter (FACS). A total of 27 control and 33 oral contraceptive users were studied. In comparison to the control group, there was no significant difference between the two groups in percentage or absolute numbers of total T cells, helper cells, suppressor/cytotoxic cells or natural killer cells. This study suggests that the increase in herpes virus, C. trachomonas, candida, and other infections in women taking oral contraceptives is not related to alterations in the numbers of T lymphocyte subsets or in levels of NK cells.

Contraceptives, Oral↗