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Biomedical subjects

E Bond

Publications and source records attributed to E Bond.

At least 19 recordsLinked to original sources

Single-nucleotide polymorphisms in the p53 pathway.

A cell culture assay has been developed that detects and validates single-nucleotide polymorphisms (SNPs) in genes that populate the p53 pathway. One hundred thirteen EBV-transformed human B-lymphocyte cell lines obtained from a diverse population were employed to measure the apoptotic response to gamma radiation. Each cell line undergoes a reproducible, characteristic frequency of apoptosis, and the response of the population forms a normal distribution around a median of 35.5% apoptosis with a range from 12% to 58% apoptosis. Polymorphisms in the AKT1 and Perp genes significantly affect the frequency of apoptosis. The assay can detect both racial and sexual dimorphisms in these genes and has the ability to demonstrate epistatic relationships within the p53 pathway. The cell lines used in this assay provide biological materials to explore the molecular basis of the polymorphisms.

Black or African American↗

Effects of imatinib mesylate (STI571, Glivec) on the pharmacokinetics of simvastatin, a cytochrome p450 3A4 substrate, in patients with chronic myeloid leukaemia.

The inhibition by imatinib of the cytochrome p450 3A4 isoenzyme may reduce the CYP3A4-mediated metabolic clearance of clinically important coadministered drugs. The main purpose of this study was to evaluate the effect of the coadministration of imatinib on the pharmacokinetics of simvastatin, a probe CYP3A4 substrate. In total, 20 patients with chronic myeloid leukaemia received an oral dose of 40 mg of simvastatin on study day 1. On study days 2-7, each patient received 400 mg of imatinib once daily orally and on study day 8, 400 mg imatinib together with 40 mg of simvastatin was given. Blood levels of simvastatin were measured predose and for 24 h postdose on study days 1 and 8. Two additional blood samples were taken for imatinib pharmacokinetic (PK) assessment on day 8 before, and 24 h after, imatinib administration. Imatinib increased the mean maximum concentration (C(max)) value of simvastatin two-fold and the area under concentration-time curve (AUC ((0-inf))) value 3.5-fold (P<0.001) compared with simvastatin alone. There was a statistically significant decrease in total-body clearance of drug from the plasma (CL/F) with a mean reduction of 70% for simvastatin (P<0.001): the mean half-life of simvastatin was prolonged from 1.4-2.7 h when given together with imatinib. No changes in imatinib PK parameters were found when given concomitantly with simvastatin. In conclusion, the coadministration of imatinib at steady state with 40 mg simvastatin increases the exposure (C(max) and AUCs) of simvastatin significantly (P<0.001) by two-three-fold. Caution is therefore required when administering imatinib with CYP3A4 substrates with a narrow therapeutic window. The coadministration of simvastatin with imatinib (400 mg) was well tolerated and no major safety findings were reported in this study.

Administration, Oral↗

In vitro activities of RWJ-54428 (MC-02,479) against multiresistant gram-positive bacteria.

RWJ-54428 (MC-02,479) is a new cephalosporin with a high level of activity against gram-positive bacteria. In a broth microdilution susceptibility test against methicillin-resistant Staphylococcus aureus (MRSA), RWJ-54428 was as active as vancomycin, with an MIC at which 90% of isolates are inhibited (MIC(90)) of 2 microg/ml. For coagulase-negative staphylococci, RWJ-54428 was 32 times more active than imipenem, with an MIC(90) of 2 microg/ml. RWJ-54428 was active against S. aureus, Staphylococcus epidermidis, and Staphylococcus haemolyticus isolates with reduced susceptibility to glycopeptides (RWJ-54428 MIC range, < or = 0.0625 to 1 microg/ml). RWJ-54428 was eight times more potent than methicillin and cefotaxime against methicillin-susceptible S. aureus (MIC(90), 0.5 microg/ml). For ampicillin-susceptible Enterococcus faecalis (including vancomycin-resistant and high-level aminoglycoside-resistant strains), RWJ-54428 had an MIC(90) of 0.125 microg/ml. RWJ-54428 was also active against Enterococcus faecium, including vancomycin-, gentamicin-, and ciprofloxacin-resistant strains. The potency against enterococci correlated with ampicillin susceptibility; RWJ-54428 MICs ranged between < or = 0.0625 and 1 microg/ml for ampicillin-susceptible strains and 0.125 and 8 microg/ml for ampicillin-resistant strains. RWJ-54428 was more active than penicillin G and cefotaxime against penicillin-resistant, -intermediate, and -susceptible strains of Streptococcus pneumoniae (MIC(90)s, 0.25, 0.125, and < or = 0.0625 microg/ml, respectively). RWJ-54428 was only marginally active against most gram-negative bacteria; however, significant activity was observed against Haemophilus influenzae and Moraxella catarrhalis (MIC(90)s, 0.25 and 0.5 microg/ml, respectively). This survey of the susceptibilities of more than 1,000 multidrug-resistant gram-positive isolates to RWJ-54428 indicates that this new cephalosporin has the potential to be useful in the treatment of infections due to gram-positive bacteria, including strains resistant to currently available antimicrobials.

Anti-Bacterial Agents↗

Dental manifestations in severe combined immunodeficiency following bone marrow transplantation.

Severe combined immunodeficiency (SCID) is a rare primary immunodeficiency disorder with an estimated overall frequency of 1 in 75 000 live births. Bone marrow transplantation is the only curative treatment available. Using T cell-depleted HLA non-identical bone marrow requires preconditioning with a short course of cytotoxic chemotherapy. We report severe dental developmental anomalies in three such patients under long-term follow up.

Bone Marrow Transplantation↗

Emerging and reemerging infectious diseases: a multidisciplinary perspective.

Predictions that infectious diseases would be eliminated as a major threat to human health have been shattered by emerging and reemerging infections, among them acquired immunodeficiency syndrome (AIDS), hemorrhagic fevers, marked increases in infections caused by antimicrobial-resistant bacteria, and the resurgence of tuberculosis and malaria. Understanding the dynamics of emerging and reemerging infections is critical to efforts to reduce the morbidity and mortality of such infections, to establish policy related to preparedness for infectious threats, and for decisions on where to use limited resources in the fight against infections. In order to offer a multidisciplinary perspective, 23 infectious disease specialists, epidemiologists, geneticists, microbiologists, and population biologists participated in an open forum at Emory University on emerging and reemerging infectious diseases. As summarized below, the group addressed questions about the definition, the identification, the factors responsible for, and multidisciplinary approaches to emerging and reemerging infections.

Acquired Immunodeficiency Syndrome↗

Increased urine catecholamines and cortisol in women with irritable bowel syndrome.

OBJECTIVES: There are few data on the sympathetic nervous system and the hypothalamic-pituitary-adrenal axis in individuals with chronic GI symptoms. The current study was designed to describe and compare urine catecholamine (norepinephrine, epinephrine) and cortisol levels in women diagnosed with irritable bowel syndrome (IBS-patients), women who report similar symptom levels but had not sought health care services (IBS-nonpatients; IBS-NP), and asymptomatic (control) women. METHODS: Seventy-three women (24 IBS; 24 IBS-NP; 25 controls) were interviewed for demographic, GI, gynecological, and psychological data and then followed for two menstrual cycles with a daily health diary. Urine samples were obtained in the evening and morning at specific phases across two menstrual cycles. RESULTS: Women in the IBS group had significantly higher PM and AM urine norepinephrine levels. Urine epinephrine and cortisol levels were also generally higher in women with IBS. Differences in neuroendocrine indicators of arousal were not accounted for by differences in demographic variables, lifestyle characteristics, menstrual distress, or average daily measures of anxiety or depression. CONCLUSIONS: Increases in indicators of sympathetic nervous system activation in women seeking health care for IBS may reflect greater symptom distress or may contribute to increased symptom distress.

Adolescent↗

Women with gastrointestinal symptoms: implications for nursing research and practice.

Irritable bowel syndrome and functional bowel disorder are diagnoses used to describe chronic GI symptoms for which no overt pathological condition can be identified. Symptoms are more common in women and are frequently followed in gastroenterology clinics. The purpose of this article is to provide an overview of the research linking GI symptoms and reproductive cycling and to discuss implications for practice. GI symptoms such as stomach pain and nausea are highest during menses compared with other cycle phases; also, stool consistency is loosest at menses. This pattern is present in control subjects. In women with irritable bowel syndrome the same pattern is seen but with higher symptom intensity. Although animal studies have demonstrated that estrogen and progesterone modulate contractile function of some GI segments, in humans, symptoms are highest when these hormones are at the lowest levels. Thus, symptoms in women may be related to decreasing ovarian hormone levels or to other circulating hormones or factors which vary with the menstrual cycle. Additionally, other factors such as stress aggravate symptoms. Therapeutics directed toward increasing patient awareness of cyclic patterns in symptom complaints, for example, via the use of daily symptom diaries may be a useful adjunct to dietary, pharmacological, and other therapies.

Autonomic Nervous System↗

Thyrotropin-releasing hormone stimulates intestinal transit in young rats.

The effect of intracisternal injection of thyrotropin-releasing hormone (TRH) on small intestinal transit of a charcoal bolus was investigated in 14-, 21-, 28- and 35-day-old and adult rats. Intracisternal TRH (15 micrograms in 2 microliters) was administered, and transit (distance traveled by the charcoal) was measured 120 min later. In all age groups, intracisternal TRH increased charcoal transit significantly (P less than 0.05) as compared to saline-treated controls. This increase in transit was not mimicked by intravascular TRH, and it was blocked in all age groups by prior intraperitoneal injection of atropine (2 micrograms/g body weight). Vagotomy blocked TRH-induced increases in small intestine transit in rats of 28 days and older. Prior intraperitoneal injection of the antiserotonin compound, cyproheptadine (1 microgram/g body weight) reduced TRH-induced increases in small intestine transit in all age groups. These results demonstrate that centrally administered TRH stimulates small intestine transit through both cholinergic and serotonergic mechanisms in rats as early as 14 days of age.

Age Factors↗

Phorbol myristate acetate: in vivo effects upon neutrophils, platelets, and lung.

Phorbol myristate acetate is a potent aggregator of platelets. It was found that it was similarly potent in aggregating neutrophils and in producing striking thrombocytopenia and neutropenia when infused intravenously into rabbits. Aggregation and cytopenia were further correlated in that both types of responses developed abruptly and persisted for more than 90 minutes. Animals infused with 40 microgram/kg of the phorbol ester exhibited moderately severe respiratory distress. Their respiratory rate doubled shortly after the infusion, and this tachypnea persisted for more than 2 hours. At necroscopic examination, the lungs of these rabbits contained two outstanding abnormalities: numerous foci of alveolar hemorrhage and extensive intravascular accumulations of platelets and neutrophils. Thus, these animals had evidence of increased permeability and potential occlusion of the pulmonary microvasculature. Increased permeability, occlusion of lung blood vessels, or the occurrence of both processes was further indicated in studies on animals pre-infused with the plasma protein marker 125I-albumin: animals infused with the phorbol ester had a significantly increased amount of this label in their lungs in spite of thorough postmortem perfusion of their pulmonary vasculature with saline and fixative. We conclude that phorbol myristate acetate has actions in vivo that resemble those of a variety of other platelet (eg, arachidonic acid) and neutrophil (eg, chemotactic factors) aggregating agents that cause cytopenia and lung dysfunction. However, compared with these other agents, the phorbol ester produces respiratory distress of intermediate severity and greater duration. The drug, therefore, induces a syndrome that more closely resembles that seen in a variety of clinical and experimental conditions that associate shocklike states with cytopenia and lung dysfunction. It may serve as a useful tool in the study of the pathophysiology of these states as well as in those produced by other aggregating agents.

Animals↗