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Biomedical subjects

E O'Rourke

Publications and source records attributed to E O'Rourke.

At least 19 recordsLinked to original sources
PubMed2007

Management and prevention of adverse effects related to treatment of liver tumours with 90Y microspheres.

BACKGROUND AND AIM: Selective internal radiation therapy with 90Y microspheres (SIR spheres) is increasingly used in the treatment of extensive liver tumours. Careful selection and preparation of patients are necessary to avoid possible adverse effects. We aimed to evaluate the incidence and severity of adverse effects resulting from the administration of SIR spheres during therapy. MATERIALS AND METHODS: Between June 2004 and August 2006, 21 patients (11 women and 10 men; age range 40-75 years; mean, 58 years) with a wide range of extensive liver tumours were treated with SIR spheres. The mean administered dose was 1.87 GBq (range 1.2-2.5 GBq). During the follow-up period of 26 months, all adverse effects were monitored and classified according to the National Cancer Institute criteria. RESULTS: Four patients had adverse effects: one case of cholecystitis followed by fibrosis and portal hypertension, one case of peptic ulceration and two cases of radiation hepatitis. All cases responded to appropriate therapy. CONCLUSION: Proper selection of patients and accurate interpretation of pre-treatment investigations are vital for minimizing adverse effects following therapy with SIR spheres. In our experience, all adverse effects were moderate with no life-threatening consequences.

Adult↗
PubMed2001

Lessons learned from the development of enzyme therapy for Gaucher disease.

Enzyme replacement therapy for the lysosomal storage disorders derives its impetus from the successes achieved in the treatment of Gaucher disease. After nearly two decades of persistent but unsuccessful efforts, the promise of therapy through enzyme replacement was losing credibility. Then, the fortunate intersection of two different lines of scientific research produced the necessary breakthrough. The dramatic responses to enzyme replacement therapy in patients with Gaucher disease made it immediately clear that this treatment approach was a success. Furthermore, the large number of patients with the disorder guaranteed commercial involvement. The lessons learned from the development of enzyme replacement therapy for Gaucher disease are broadly applicable to other lysosomal storage diseases and will be reviewed in this paper.

Gaucher Disease↗
PubMed1998

Simplified surveillance for nosocomial bloodstream infections.

OBJECTIVE: To compare a surveillance definition of noso comial bloodstream infections requiring only microbiology data to the Centers for Disease Control and Prevention's (CDC) current definition. SETTING: Six teaching hospitals. METHODS: We classified a representative sample of 73 positive blood cultures from six hospitals growing common skin contaminant isolates using a definition for bacteremia requiring only microbiology data and the CDC definition for primary bloodstream infection (National Nosocomial Infections Surveillance [NNIS] System review method). The classifications assigned during routine prospective surveillance also were noted, and the time required to classify isolates by the two methods was compared. RESULTS: Among 65 blood cultures growing common skin contaminant isolates obtained from adults, the agreement rate between the microbiology data method and the NNIS review method was 91%. Agreement was significantly poorer for the eight blood cultures growing common skin contaminant isolates obtained from pediatric patients. The microbiology data method requires approximately 20 minutes less time per isolate than does routine surveillance. CONCLUSIONS: A definition based on microbiology data alone yields the same result as the CDC's definition in the large majority of instances. It is more resource-efficient than the CDC's current definition.

Adult↗
PubMed1997

Mobile carers.

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Ambulances↗
PubMed1995

A 30-amino acid truncation of the microsomal triglyceride transfer protein large subunit disrupts its interaction with protein disulfide-isomerase and causes abetalipoproteinemia.

The microsomal triglyceride transfer protein (MTP) is a heterodimer composed of the multifunctional enzyme, protein disulfide-isomerase, and a unique large, 97 kDa, subunit. It is found as a soluble protein within the lumen of the endoplasmic reticulum of liver and intestine and is required for the assembly of very low density lipoproteins and chylomicrons. Mutations in MTP which result in an absence of MTP function have been shown to cause abetalipoproteinemia. Here, the gene encoding the MTP 97-kDa subunit of an abetalipoproteinemic subject, which we have previously demonstrated lacks MTP activity and protein (Wetterau, J. R., Aggerbeck, L. P., Bouma, M.-E., Eisenberg, C., Munck, A., Hermier, M., Schmitz, J., Gay, G., Rader, D. J., and Gregg, R. E. (1992) Science 258, 999-1001), was isolated and sequenced. A nonsense mutation, which predicts the truncation of the protein by 30 amino acids, was identified. To investigate if this apparently subtle change in MTP could explain the observed absence of MTP, protein disulfide-isomerase was co-expressed with either the normal or mutant MTP 97-kDa subunit in Sf9 insect cells using a baculovirus expression system. Although there were high levels of expression of both the normal and mutant forms of the MTP 97-kDa subunit, only the normal subunit was able to form a stable, soluble complex with protein disulfide-isomerase. These results indicate that the carboxyl-terminal 30 amino acids of the MTP 97-kDa subunit plays an important role in its interaction with protein disulfide-isomerase.

Abetalipoproteinemia↗
PubMed1993

Cytomegalovirus immune globulin prophylaxis in liver transplantation. A randomized, double-blind, placebo-controlled trial.

OBJECTIVE: To study the effect of cytomegalovirus immune globulin (CMVIG) on prevention of cytomegalovirus (CMV) disease and its complications in patients receiving liver transplants. DESIGN: Randomized, multicenter, placebo-controlled, double-blind trial. SETTING: Four university-affiliated transplant centers in Boston (Boston Center for Liver Transplantation). PATIENTS: One hundred forty-one liver transplant recipients completed the study. INTERVENTION: CMVIG or placebo (1% albumin) given in a dose of 150 mg/kg body weight within 72 hours of the transplant, then at weeks 2, 4, 6, and 8, and at 100 mg/kg at weeks 12 and 16. MEASUREMENTS: Patients were observed for 1 year after transplantation for the development of CMV infection, disease, pneumonia, as well as for opportunistic fungal infections, graft survival, and mortality. Weekly cultures were taken of urine, buffy coat, and throat wash for CMV for 2 months, then monthly, and at any clinical illness. RESULTS: Using a Cox proportional hazards model, CMVIG was shown to reduce severe CMV-associated disease (multi-organ CMV disease, CMV pneumonia, or invasive fungal disease associated with CMV infection) from 26% to 12% (relative risk, 0.39; 95% CI, 0.17 to 0.89). When we controlled for the use of monoclonal antibodies to T cells (OKT3), CMVIG use was still protective (relative risk, 0.39; CI, 0.17 to 0.90). Rates of CMV disease were reduced from 31% to 19% (relative risk, 0.56; CI, 0.3 to 1.1) in CMVIG recipients although no effect on rates of CMV infection, graft survival, or patient survival at 1 year were shown. When we controlled for the urgency of transplantation and OKT3 use, a reduction in CMV disease (relative risk, 0.22; CI, 0.06 to 0.81) was shown for globulin recipients for all serologic groups except for the highest risk group (the CMV-seropositive donor, CMV-seronegative group). CONCLUSION: CMVIG reduced the rate of severe CMV-associated disease in patients undergoing orthotopic liver transplantation. No effect of CMVIG on CMV donor-positive, recipient-negative liver transplant recipients was shown, suggesting a need for additional prophylactic strategies.

Acyclovir↗
PubMed1993

Purified yeast protein farnesyltransferase is structurally and functionally similar to its mammalian counterpart.

Protein farnesyltransferase (FTase) catalyses the addition of a farnesyl group to a cysteine within the so-called 'CAAX box' at the C-terminus of various proteins. In the present paper we report purification of Saccharomyces cerevisiae FTase to near-homogeneity. This was accomplished by constructing a yeast strain overproducing FTase approx. 100-fold. The purified enzyme was a heterodimer of approx. 90 kDa and consisted of 43 kDa and 34 kDa subunits. The 43 kDa subunit was shown to be the product of the DPR1 gene by using antibody raised against baculovirus-produced DPR1 polypeptide. The purified enzyme required Mg2+, showed a pH optimum of 7.8 and was most active at 50 degrees C. The Km values for farnesyl pyrophosphate and GST-CIIS (glutathione S-transferase fused to the C-terminal 12 amino acids of yeast RAS2 protein), KmFpp and KmGST CIIS, were 8.1 and 5.1 microM respectively. The enzyme was capable of farnesylating GST-CIIL (the same as GST-CIIS, except that the C-terminal serine is changed to leucine), a substrate protein for the enzyme geranylgeranyltransferase, although with a higher apparent Km than for GST-CIIS. Like its mammalian counterpart, yeast FTase activity was inhibited by peptides containing the C-terminal CAAX sequence (that is, one where C = cysteine, A = aliphatic amino acid and X = any amino acid). These results provide direct evidence for the idea that the yeast and mammalian FTases are structurally and functionally very similar.

Alkyl and Aryl Transferases↗
PubMed1991

The trk tyrosine protein kinase mediates the mitogenic properties of nerve growth factor and neurotrophin-3.

The product of the trk proto-oncogene encodes a receptor for nerve growth factor (NGF). Here we show that NGF is a powerful mitogen that can induce resting NIH 3T3 cells to enter S phase, grow in semisolid medium, and become morphologically transformed. These mitogenic effects are absolutely dependent on expression of gp140trk receptors, but do not require the presence of the previously described low affinity NGF receptor. gp140trk also serves as a receptor for the related factor neurotrophin-3 (NT-3), but not for brain-derived neurotrophic factor. Both NGF and NT-3 induce the rapid phosphorylation of gp140trk receptors and the transient expression of c-Fos proteins. However, NT-3 appears to elicit more limited mitogenic responses than NGF. These results indicate that the product of the trk proto-oncogene is sufficient to mediate signal transduction processes induced by NGF and NT-3, at least in proliferating cells.

Animals↗
PubMed1991

The trk proto-oncogene encodes a receptor for nerve growth factor.

Two classes of receptors with distinct affinities for nerve growth factor (NGF) have been identified. The low affinity receptor (Kd approximately 10(-9) to 10(-8) M) is a cysteine-rich glycoprotein encoded by the previously characterized LNGFR gene. The structural nature of the high affinity receptor (Kd approximately 10(-11) to 10(-10) M) has yet to be established. In this study we show that the product of the human trk proto-oncogene (gp140trk) binds NGF with high affinity. Moreover, NGF could be chemically cross-linked to the endogenous gp140trk present in rat PC12 pheochromocytoma cells as well as to gp140trk ectopically expressed in mouse fibroblasts and in insect Sf9 cells. High affinity binding of NGF to gp140trk can occur in the absence of low affinity LNGFR receptors, at least in nonneural cells. Addition of NGF to PC12 cells elicits rapid phosphorylation of gp140trk on tyrosine residues and stimulates its tyrosine kinase activity. These results indicate that gp140trk is a functional NGF receptor that mediates at least some of the signal transduction processes initiated by this neurotrophic factor.

Adrenal Gland Neoplasms↗