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Biomedical subjects

D Farrell

Publications and source records attributed to D Farrell.

At least 19 recordsLinked to original sources
PubMed2000

Antiplatelet effects of MK-852, a platelet fibrinogen receptor antagonist, in healthy volunteers.

MK-852, a cyclic heptapeptide, is a potent platelet fibrinogen receptor antagonist. When administered to normal healthy male subjects by 1- and 4-hour constant rate intravenous infusions, it provides a generally well-tolerated and reversible means of inhibition of platelet function. At infusion rates of 1 microgram/kg/min for 1 hour and 0.44 microgram/kg/min for 4 hours, respectively, MK-852 extended baseline bleeding time by greater than 2.2-fold and 2.6-fold, inhibited ADP-induced platelet aggregation by 76% and 69%, and inhibited collagen-induced platelet aggregation by 65% and 67%, respectively. The pharmacokinetics of MK-852 include an elimination half-life of approximately 2 hours, total clearance of about 150 ml/min, and volume of distribution of about 18 liters. Examination of the relationship between MK-852 whole-blood concentration in vitro and inhibition of platelet aggregation showed an EC50 of about 55 ng/ml and a Hill coefficient of 1.55. The infusions were generally well tolerated, with no study drug-related changes in blood counts or biochemical profiles.

Adenosine Diphosphate↗
PubMed1999

A tailored multimedia nutrition education pilot program for low-income women receiving food assistance.

This article describes the development and pilot evaluation of a tailored multimedia program to improve dietary behavior among 378 low-income women enrolled in the Food Stamp program in Durham, North Carolina. After randomization to intervention or control groups, participants completed a baseline survey and were resurveyed 1-3 months post-intervention. Measures included dietary fat intake assessed using a brief food-frequency questionnaire, stage of change, knowledge of low-fat foods, self-efficacy and eating behavior questions. The computer-based intervention consisted of a tailored soap opera and interactive 'info-mercials' that provided individualized feedback about dietary fat intake, knowledge and strategies for lowering fat based on stage of change. At follow-up, intervention group participants had improved significantly in knowledge (P < 0.001), stage of change (P < 0.05) and certain eating behaviors (P < 0.05) compared to the control group. Both study groups had lowered their reported fat intake markedly at follow-up (P < 0.001), but did not differ significantly from each other. A majority of participants rated the program as very helpful and were interested in using a similar program in the future. The findings of this pilot study suggest that computerized tailored self-help health promotion programs may be effective educational interventions for lower income and minority populations.

Adult↗
PubMed1994

Pyemotes species strongly implicated in an outbreak of dermatitis in a Queensland country hospital.

An acute outbreak of itchy papulovesicular dermatitis occurred among nursing home patients in a small Queensland country hospital west of Toowoomba. Mites, Pyemotes species, were found in the immediate environment of the hospital and have been implicated as the causative agent. This case illustrates the importance of examination of environmental specimens for ectoparasites in cases of unexplained dermatoses.

Dermatitis↗
PubMed1994

Opportunities for alcohol screening and counseling in primary care.

BACKGROUND: The physician can be an important part of a comprehensive strategy to assist persons with alcohol problems. This study was designed to contribute to the development of physician-initiated brief interventions for patients with alcohol problems by incorporating into an existing screening instrument questions that solicit information relevant to behavior change strategies. METHODS: Adult patients from 12 family practices in North Carolina (N = 2716) completed a self-administered questionnaire assessing alcohol consumption and other health-related behaviors. Alcohol problems were assessed using the four-item CAGE (Have you ever felt you should cut down on your drinking? Have people annoyed you by criticizing your drinking? Have you ever felt bad or guilty about your drinking? Have you ever had a drink first thing in the morning to steady your nerves, or to get rid of a hangover?). For this study, CAGE was adapted to address only the past 12 months. Patient interest in reducing the amount of alcohol consumed was measured using the Transtheoretical Model developed by Prochaska and colleagues. Patients were also asked about their motives for and barriers to reducing consumption. RESULTS: Five percent of all patients and 9% of patients who reported drinking alcohol gave positive responses on at least two CAGE items. Patients with three or four positive CAGE responses were 74% more likely to report an interest in reducing alcohol consumption than were those with one or two. Intrinsic reasons were the most important motives for reducing consumption. No pattern was found in barriers. CONCLUSIONS: We found that in the management of patients with alcohol-related problems, there are many clinical opportunities for patient counseling and referral in the family practice setting. Individually tailored brief interventions that take into consideration the patient's interest in, motives for, and barriers to reducing alcohol consumption are likely to be successful for the family practice physician.

Adolescent↗
PubMed1993

MK-383 (L-700,462), a selective nonpeptide platelet glycoprotein IIb/IIIa antagonist, is active in man.

BACKGROUND: Fibrinogen-dependent cross-linking of glycoprotein (GP) IIb/IIIa on activated platelets is the final mechanism leading to platelet aggregation. Inhibition of this mechanism may result in a novel antithrombotic agent. We studied the activity of MK-383 (L-700,462), a new, nonpeptide GPIIb/IIIa antagonist, in vitro and in vivo, in man. METHODS AND RESULTS: MK-383, a nonpeptide tyrosine derivative, dose-dependently inhibited fibrinogen-dependent platelet aggregation, in vitro. Binding of 125I-labeled fibrinogen to activated platelets was prevented in a competitive manner with an IC50 of 10 +/- 4.2 nmol/L. The activity and tolerability of MK-383 were evaluated in a two-part double-blind, placebo-controlled, dose-escalation study in healthy male subjects using 1- and 4-hour intravenous infusions. Effects on ADP- and collagen-induced ex vivo platelet aggregation (APA or CPA) and template bleeding time (TBT) were evaluated. Twenty-four subjects participated in the 1-hour part. Six received placebo and 18 MK-383 in doses ranging from 0.05 to 0.40 microgram.kg-1 x min-1. MK-383 inhibited platelet aggregation and prolonged bleeding time in a dose-dependent manner. APA and CPA were totally inhibited at the end of infusion of 0.4 microgram.kg-1 x min-1 and returned to 55% and 89% of baseline, respectively, at 3 hours after infusion. TBT was prolonged at this dose from 5.0 +/- 1.3 minutes predose to 22.7 +/- 6 minutes at the end of the infusion (P < .01) and was normalized by 3 hours after infusion. In the 4-hour infusion part, 15 subjects received MK-383 (0.1 to 0.2 microgram.kg-1 x min-1), and five received placebo. Complete inhibition of ex vivo platelet aggregation was seen at 0.15 and 0.2 microgram.kg-1 x min-1. At 0.2 microgram.kg-1 x min-1, TBT was prolonged from 4.4 +/- 1.2 to 23.9 +/- 4.3 minutes at the end of infusion (P < .01) and remained slightly prolonged 3 hours after infusion (7.2 +/- 1.8 minutes). No adverse effects were observed in any of the 33 subjects receiving MK-383. CONCLUSIONS: The results from this study indicate that MK-383 appears to be well tolerated and active in man. It is the first nonpeptide GPIIb/IIIa antagonist that can be used to investigate the antithrombotic potential of this new class of antiplatelet agents.

Bleeding Time↗
PubMed1993

Free peritoneal tumour cell identification in patients with gastric and colorectal cancer.

The finding of free tumour cells within the peritoneum at the time of laparotomy for gastrointestinal cancer is an important indicator of prognosis and may help select treatment. The aim of this study was to improve the methods whereby these cells could be retrieved and identified. Free peritoneal cancer cells were found in 6 out of 18 gastric cancer patients. All 6 patients had tumour invasion through to the serosa and subsequently died of tumour recurrence. None of the 18 Dukes' B and C colorectal cancer patients had free peritoneal cancer cells. Only 2 of a further 5 patients with extensive colorectal tumour spread had positive cytologies. The conventional mucin stain Periodic Acid Schiff (after diastase digestion) and the monoclonal antibody stain B72.3 were the most useful in identifying free peritoneal cancer cells. Peritoneal brushings did not offer any advantages over conventional peritoneal washings in the retrieval of free tumour cells.

Adult↗
PubMed1992

Persistence of measles antibody after revaccination.

To evaluate persistence of measles antibody after revaccination, antibody levels were measured 6 years after revaccination of 40 hemagglutination-inhibition (HAI) antibody-negative students who had participated in a serosurvey in Massachusetts. Twelve subjects who had been HAI antibody-positive and were not revaccinated were included as a comparison group. Before revaccination, 7 revaccinees had no detectable plaque reduction neutralization (PRN) antibody (group 1) and 33 had low levels of PRN antibody (group 2). Three weeks after revaccination, all in group 1 and 30 (90%) of 33 in group 2 had developed a fourfold or greater rise in PRN antibody. Six years after revaccination, all subjects had PRN-detectable antibody. However, 12 in group 2 (36%) had antibody titers less than or equal to 1:120 compared with none in group 1 (P less than .01). Persons without PRN antibody will respond to revaccination and maintain protective antibody titers. In contrast, persons with low levels of PRN antibody may respond initially to revaccination, but their antibody titers may fall again to low levels.

Adolescent↗
PubMed1991

Successful immunization of infants at 6 months of age with high dose Edmonston-Zagreb measles vaccine. Cite Soleil/JHU Project Team.

A group of 2097 Haitian infants 6 to 11 months of age were randomized to receive Schwarz or Edmonston-Zagreb strain measles vaccines containing 10- to 500-fold more vaccine viral particles than standard potency vaccines. No unusual adverse reactions were noted. Edmonston-Zagreb vaccines were more effective than equivalent doses of Schwarz vaccines as measured by the proportion of vaccinated children with measles antibody concentrations greater than or equal to 200 mIU/ml 2 months after vaccination and the persistence of antibody at 18 to 24 months of age. High titer Edmonston-Zagreb vaccine administered at 6 months of age induced antibody concentrations greater than or equal to 200 mIU/ml in 83% of infants by plaque reduction neutralization and 93% of infants by enzyme-linked immunosorbent assay with high rates of antibody persistence at 12 to 24 months of age. The World Health Organization recommends high titer Edmonston-Zagreb measles vaccines for routine use at 6 months of age in areas where measles is an important cause of mortality in young infants.

Antibodies, Viral↗
PubMed1990

Cytological differences between normal and malignant human cell populations in culture.

Cells from early-passage cultures of normal and malignant human tissues were analyzed for the presence of multiple nucleoli and tri- or multipolar mitoses; these properties are characteristic of malignant cell populations in tissue sections. For the cell types examined the presence of tri- or multipolar mitoses was characteristic of cells of malignant origin. Within epithelial cell populations, cells containing more than 4 nucleoli were found in populations of malignant but not of normal origin; this distinction did not apply to fibroblast populations. Large numbers of cells must be analyzed quantitatively to establish the distinctions described here, since they are properties characteristic of populations, not of individual cells. This approach may facilitate identification of normal and malignant cell populations in primary and early-passage culture.

Cell Nucleus↗
PubMed1983

Freud's 'thought-transference', repression, and the future of psychoanalysis.

Psychoanalysts since Freud have largely neglected his important, paradigmatic ideas on the possibility of 'thought-transference' (telepathy) as an influence in mental life. A chance recording of two dreams which proved to coincide in some detail with distant reality events again suggests evidence in favour of the telepathy hypothesis. On interpretation, one of these dreams reveals even greater correspondence with the reality event and shows the mechanism of transformation of the repressed wish from latent dream content into manifest dream, utilizing a number of elements of the dream instigator, an apparently telepathically received day residue. Working with this material proceeded against very strong resistance, most evident in repeated forgetting of one or another bit of the clinical data. This has been the fate of ideas pertaining to the occult since Freud's first formulations, as is documented here by references to the early history of psychoanalysis. The issue now and for the future is whether psychoanalysis will continue to ignore the crucial question of validity in regard to the telepathy hypothesis. The psychoanalytic method is uniquely qualified to investigate so-called parapsychological phenomena and has the same obligation to do so as with other mental events. We need to examine the evidence in spite of the threat posed to our conventional understanding of the limits of the mind by the very act of acknowledging the question. If we can overcome our resistance to undertaking this task, we may find that, once again, Freud pointed the way towards discovery of a new paradigm in science.

Attitude to Death↗
PubMed1979

DNA polymerases in mouse spermatogenic cells separated by sedimentation velocity.

Activity levels of DNA polymerase alpha and DNA polymerase beta have been measured in mouse spermatogenic cells separated by sedimentation velocity. Testes from prepuberal (17 day old) and sexually mature mice were dissociated and separated by unit gravity sedimentation into 6 populations of cells. Phase contrast microscopy and [3H]thymidine labeling kinetics revealed that at least 85% of the cells in fraction A were pachytene-stage primary spermatocytes, fraction B was enriched for primary spermatocytes and round spermatids, fraction C contained spermatogonia and/or pre-leptotene primary spermatocytes and later stages of spermatids (no spermatids were present in fraction C from the testes of 17 day old mice) and fractions D to F contained mixed populations of cells, many in later stages of spermiogenesis. When expressed as activity in 10(6) cells or as a specific activity, fractions A, B, and C from mature animals population initially loaded onto the gradient while fractions D, E and F had activity levels similar to or below the population of dissociated cells. The ratio of activity between the DNA polymerases was constant in fractions A, B, and C, but in fractions D, E, and F, the ratio decreased due to a more rapid decline of activity of polymerase alpha. A comparison of activity levels in fraction C from prepuberal and sexually mature mice revealed an increase in DNA polymerase alpha activity and a decrease in the activity of DNA polymerase beta in the cells from the 17 day old animals.

Animals↗
PubMed1977

RNA polymerase activity in bovine spermatozoa.

Washed mature spermatozoa from bulls incorporate ribonucleoside triphosphates into RNA using an endogenous template. Maximum incorporation was observed at 31 degrees C in the presence of MgCl2, all four ribonucleoside triphosphates, beta-mercaptoethanol, and glycine sodium hydroxide buffer at pH 9.0. The amount of synthesis was linearly dependent upon the concentration of spermatozoa and continued for at least 4 h. Digestion studies revealed the RNA to be present in a protected (intracellular?) location in the spermatozoa. The RNA synthesis was inhibited by ethidium bromide, rifampicin, acriflavine, actinomycin D, and caffeine, but not by alpha-amanitine or rifamycin SV. Fractionation of the spermatozoa by sonication and separation of the heads and tails by centrifugation through a discontinuous gradient revealed that more than half of the total RNA polymerase activity was associated with the tail fraction.

Acriflavine↗