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Biomedical subjects

D Webster

Publications and source records attributed to D Webster.

At least 55 records · Page 3Linked to original sources
PubMed1996

A comparison of 600 and 200 mg mifepristone prior to second trimester abortion with the prostaglandin misoprostol.

OBJECTIVE: To compare the use of 600 and 200 mg mifepristone prior to second trimester termination of pregnancy with the prostaglandin misoprostol. DESIGN: A randomised study. SETTING: A Scottish teaching hospital. PARTICIPANTS: Seventy women undergoing legal induced abortion between 13 and 20 weeks of gestation. INTERVENTION: Administration of either 600 or 200 mg mifepristone 36 to 48 hours prior to prostaglandin. MAIN OUTCOME MEASURE: Induction-abortion interval. RESULTS: The geometric mean induction abortion interval was 6.9 (95% CI 5.8-8.4) h and 6.9 (95% CI 5.8-8.2) h in the 600 and 200 mg groups, respectively (no significant difference). The median dose of misoprostol was 1600 micrograms (three doses) in each group. Analgesic requirements and prostaglandin-related side effects were similar between groups. Overall, 11.4% of women required surgical evacuation of the uterus as a result of retained placenta. CONCLUSIONS: The dose of mifepristone used in second trimester abortion can be reduced from 600 to 200 mg.

Abortifacient Agents, Steroidal↗
PubMed1996

Sustained retroviral gene marking and expression in lymphoid and myeloid cells derived from transduced hematopoietic progenitor cells.

The expression of antiviral genes in human hematopoietic stem or progenitor cells has been proposed as a strategy for gene therapy of AIDS. To be successful, this strategy requires safe and efficient transfer of the therapeutic gene into hematopoietic cells and gene expression has to be maintained in HIV susceptible cells following differentiation. We have used retroviral vectors to transfer the gene for a transdominant inhibitor of HIV replication (RevM10) into CD34+ stem/progenitor cells isolated from human umbilical cord blood (UCB). Following transduction, cells were allowed to differentiate either in vitro in clonogenic assays and long-term stromal cell cultures or in human thymus implanted in immunodeficient scid/scid mice in vivo (SCID-hu). Following differentiation and expansion, multiple lineages of cells were shown to carry the transgene. A higher percentage of gene-marked progenitor cells (10-30% in most cases) were detected in methylcellulose colony assays and in long-term stromal cell cultures (1-5%). In contrast, gene-marked T cells derived from transduced CD34+ cells in a SCID-hu model were detected at an even lower frequency (0.01-1%). RevM10 RNA expression was detected in CD34+ cells immediately after transduction and was maintained after in vitro differentiation of those cells into CD14+ myeloid cells. In T cells, the RevM10-specific RNA was detectable by RT-PCR and also by semiquantitative RNase protection. These findings demonstrate that LTR-driven gene expression is sustained in relevant cells derived from retrovirus-transduced hematopoietic progenitor cells after extensive differentiation in vitro and in vivo and suggest that stringent in vivo, rather than in vitro assays, may be a better preclinical system to improve gene marking and expression in hematopoietic cells.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Incongruent follicular development reduces gamete intrafallopian transfer pregnancy rate.

OBJECTIVE: To test the null hypothesis that asymmetric or incongruent follicular development does not influence GIFT pregnancy rates (PRs). DESIGN: A prospective comparative study. SETTING: Tertiary referral center for infertility. PATIENT(S): Ninety-three consecutive infertile patients having GIFT. INTERVENTION(S): Controlled ovarian hyperstimulation and GIFT. MAIN OUTCOME MEASURE(S): The incongruity ratio as a parameter of the asymmetry in follicular development and the clinical PR. RESULT(S): An inverse relationship was observed between the degree of incongruity and the clinical PRs. In patients with an incongruity ratio < 1.5, the clinical PR was 56.1%. In patients with an incongruity ratio > or = 1.5, the clinical PR was only 17.3%. CONCLUSION(S): Incongruent follicular development during controlled ovarian hyperstimulation has a marked negative influence on the outcome of GIFT cycles. Factors such as side of the gamete transfer and oocyte quality did not account for the observed differences.

Adult↗
PubMed1995

Newborn screening for congenital adrenal hyperplasia in New Zealand.

OBJECTIVE: To evaluate the efficacy and efficiency of newborn screening for classic congenital adrenal hyperplasia (CAH) in New Zealand. DESIGN: All infants younger than 6 weeks of age identified by newborn screening between December 1984 and December 1993 were included. RESULTS: 23 cases of classic CAH (20 salt-losers) were identified. The incidence of classic CAH was 1 in 23,344. Screening identified 3 of 9 virilized female infants whose disease had not been detected clinically. Screening alone identified all 11 male infants. Notification of cases occurred at 11 +/- 3 days of age. There was a delay in treatment of the group identified by screening alone (n = 14) until 13 days of age (range, 4 to 35 days); at that time 11 infants had hyponatremia and 10 had hyperkalemia. Symptoms of vomiting, poor feeding, and shock were common after 10 days of age (2/10, < 10 days, and 8/8, 11 to 16 days of age). CONCLUSIONS: Newborn CAH screening is the only method of identifying male infants with classic CAH without a family history of CAH before symptoms develop, as well as a significant portion of overlooked virilized female infants. So that clinical or significant biochemical deterioration can be avoided, pediatrician notification of screening results and treatment should be started before 10 days of age.

Adrenal Hyperplasia, Congenital↗
PubMed1994

Molecular cloning of a proteolytic antibody light chain.

The cDNA for an antibody light chain raised by immunization against vasoactive intestinal peptide (VIP) was cloned in a bacterial expression vector, and the recombinant light chain was purified to electrophoretic homogeneity. The light chain catalyzed the hydrolysis of VIP efficiently owing to its comparatively high affinity for the substrate. In control experiments, the catalytic activity was preserved at a constant level after further chromatography of the light chain on anion-exchange and gel-filtration fast protein liquid chromatography columns, and it was removed by immunoadsorption with immobilized anti-mouse light chain antibody. The amide bond linking methylcoumarinamide (MCA) and arginine in a tripeptide unrelated in sequence to VIP was cleaved by the light chain with lower affinity and kinetic efficiency (kcat/Km). Hydrolysis of the peptidyl-MCA conjugate was inhibited competitively by the alternate substrate, VIP. The Ki and Km values for VIP were in the same range, indicating that peptide-MCA and VIP hydrolysis occurs at a common catalytic site in the light chain. Molecular modeling suggested the presence of a serine protease-like site in the light chain. This was supported by inhibition of the hydrolytic activity by serine protease inhibitors, but not by inhibitors of other classes of proteases. These observations suggest a poorly discriminatory catalytic site, with specificity for VIP arising chiefly by means of the antigen recognition function of the light chain combining site.

Amino Acid Sequence↗
PubMed1994

Caring, curing, and brief therapy: a model for nurse-psychotherapy.

Traditional models of psychotherapy have failed to meet the demands for accessible, cost-effective, and accountable mental health services. This traditional approach to mental health based on the received view of science is deconstructed in terms of its cure-orientation and contrasted with the care-orientation of nursing that is more consistent with postmodern ideas of science. Methods of brief, intermittent or possibility-oriented therapy are suggested as ways to actualize a care-orientation to mental health nursing that is more consistent with nursing's values and is more accessible to the needs of the consumer.

Activities of Daily Living↗
PubMed1992

Re-evaluation of the tympanic thermometer in the emergency department.

STUDY OBJECTIVE: A study was undertaken to re-evaluate tympanic temperatures using a commonly used portable infrared tympanic thermometer. DESIGN: Temperatures were recorded sequentially at two body sites using an electronic digital thermometer and an infrared tympanic thermometer. The tympanic thermometer was set to the core equivalency setting. SETTING: The emergency department of a Level 2 trauma center. TYPE OF PARTICIPANTS: Seventy-nine pediatric patients presenting to the ED. MEASUREMENTS AND MAIN RESULTS: Mean temperatures in the tympanic and rectal temperature groups were 38.5 +/- 1.08 C and 38.8 +/- 1.02 C, respectively (P greater than .05). The overall correlation of rectal and tympanic temperatures was 0.93 (P much less than .001). Stratifying the data by age resulted in a weakened correlation for patients 3 months of age and younger. For all strata, the sensitivity, specificity, positive predictive value, and negative predictive value of the tympanic thermometer for predicting fever were 96.6%, 100%, 100%, and 90.1%, respectively; for patients more than 3 months of age, the values were 100% in all categories. CONCLUSION: Our findings indicate that the First Temp infrared tympanic thermometer accurately detected fever in a pediatric population more than 3 months old. Results were inconclusive in patients less than 3 months old.

Body Temperature↗
PubMed1990

Occlusive vascular stapling in a canine inferior vena cava model.

A canine model for inferior vena cava resection was devised to study the biomechanical and clinical applications of the cartridge stapler, which applies a triple staggered staple line. Eighteen mongrel dogs were subjected to subhepatic, suprarenal inferior vena cava occlusion with excision of the excluded segment. At 1 hour, six dogs were killed and inferior vena cava sizes and pressures were measured. All staple lines were intact. The inferior vena cava bursting pressure was 150 to 300 mm Hg. Ten dogs survived to 6 weeks and underwent repeat laparotomy with excision and measurement of the remaining inferior vena cava. Mean diameter was 1.9 cm. No evidence of staple line leakage was found despite chronic pressures to 39 cm H2O: median static bursting pressures were 250 mm Hg. Vein wall thickness of greater than 0.24 mm were all satisfactorily stapled. Histologic examination revealed normal reendothelialization, with improved healing at higher chronic pressures. No evidence of inflammation at the staple line or foreign body reaction was found. We conclude that a triple staple line provides secure, rapid venous occlusion that can withstand supraphysiologic stresses immediately and at 6 weeks.

Animals↗
PubMed1990

Failure of influenza vaccine to prevent two successive outbreaks of influenza A H1N1 in a school community.

Forty nine of the 149 boys (33%) at a preparatory school fell ill at the beginning of the autumn term 1986 with symptoms of influenza. One hundred and eighty two of the 470 pupils (39%) in the senior part of the same school had similar symptoms of influenza at the beginning of the spring term 1987. A new variant of influenza A H1N1 virus was isolated from both outbreaks and shown to be antigenically similar to A/Taiwan/1/86. The attack rate among pupils who had previously received trivalent influenza vaccine containing A/Chile/1/83 H1N1 antigen was not significantly different from the rate among those who had never been vaccinated. It is concluded that annual vaccination of all boarding school pupils may be inappropriate.

Disease Outbreaks↗
PubMed1989

The effects of auditory deprivation on morphological maturation of the ventral cochlear nucleus.

The volumes of the auditory brainstem nuclei and age-related auditory brainstem response (ABR) thresholds were analyzed in homozygote (je/je) and heterozygote (je/+) jerker mutant mice. Altogether 97 mice were used in the study. Je/je mice never develop any hearing. The dorsal (DCN) and ventral (VCN) cochlear nuclei were found to have stopped their growth at 56 days after birth. In je/+ mutants, ABR thresholds remained normal or near-normal for 3-6 months, whereas VCN and DCN volumes remained unchanged at least after 56 days after birth. There is no significant difference in DCN volume in je/je and je/+ mice. However, the VCN volume and the cross-sectional area of globular cells were both significantly larger in je/+ than in je/je mice (P less than 0.01). These findings show that auditory deprivation during the maturation of hearing in je/je mutants causes an incomplete maturation of only the ventral cochlear nucleus.

Animals↗
PubMed1989

Assessment of responses of normal human B lymphocytes to different isolates of human immunodeficiency virus: role of normal donor and of cell line used to prepare viral isolate.

The effect of different HIV-1 isolates on normal human B lymphocyte function has been studied in vitro. Production of IgM and IgG was measured by ELISA using a "standard" non-T preparation of B cells depleted of macrophages and T cells (but not of low-density accessory cells, LDC). Only one (H9/CBL-4) of five different isolates induced polyclonal production of immunoglobulin. Apart from intrinsic differences between isolates, important inherent variables were shown to affect the response. One was the mix of cell types in the responding preparation of B cells. This was tested by examining the effects of HIV-1 isolates independently on the accessory function of LDC and on B cell function when the LDC were removed. Isolate H9/HTLV-IIIRf was nonstimulatory on a B cell preparation containing LDC and suppressive on LDC accessory function yet could enhance function of B cells when the LDC were depleted. Another variable was the donor of the normal B cells. The B cell response was consistent with each donor but varied greatly with different donors. Thus, no single explanation emerges for the hypergammaglobulinemia in some adult AIDS patients and for the hypogammaglobulinemia in some pediatric cases. Additionally, the cell lines used to propagate the virus particularly affected the assay of B cells depleted of LDC. Uninfected supernatants had different effects on the B cell function, and these host cell effects (perhaps by release of cytokines or other mediators) may be exacerbated in infected cell lines. Our data show the complexity of the abnormal B cell function in AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Interaction of campylobacter species with antibody, complement and phagocytes.

The opsonisation of four different campylobacter species for human neutrophils was studied using a chemiluminescence system and electron microscopy. Opsonisation of Campylobacter fetus, Campylobacter coli, and Campylobacter jejuni was mediated by antibody and enhanced by complement. Antibody was not, however, required for the phagocytosis of Campylobacter pylori because it activates the classical pathway of complement directly. This unusual property may be important in the pathogenesis of C pylori associated gastritis and duodenal ulcer.

Anaphylatoxins↗
PubMed1989

Adhesives in larynx repair.

Guinea pig laryngeal fractures were used as a model to compare the ease of application and effectiveness of the fibrinogen-adhesive system with the ease of application and effectiveness of cyanoacrylate glue and control fractures stinted with contralateral gelatin film. Seven fibrin adhesive-treated and two cyanoacrylate glue-treated guinea pigs were perfused after 60 and 35 days, respectively. The larynges were serial sectioned, and the wound sites were compared. The fibrinogen adhesive system was easier to dispense than cyanoacrylate glue, did not require a completely dry surface, and stabilized within 3 minutes. Cartilage segment alignment with focal, complete fracture healing and symmetrical chondrocyte proliferation were seen in fibrogen adhesive-stinted larynges. In the cyanoacrylate glue-treated larynges, there was no alignment and minimal, asymmetrical chondrocyte proliferation. Gelatin film-stinted controls exhibited similar features. Thus, fibrogen adhesive was easier to apply and more effectively bound laryngeal fractures than cyanoacrylate glue or gelatin film.

Animals↗