Biomedical subjects

P Eisenberg

Publications and source records attributed to P Eisenberg.

At least 19 recordsLinked to original sources

PubMed2004

Reversible changes in adrenocorticotropin (ACTH)-induced adrenocortical steroidogenesis and expression of the peripheral-type benzodiazepine receptor during the ACTH-insensitive period in young rats.

We previously demonstrated decreased adrenal content of a mitochondrial cholesterol transporter [peripheral-type benzodiazepine receptor (PBR)] during the first postnatal week in rats, when ACTH-inducible steroidogenesis is low. Here we report that the expression of PBR protein and mRNA increases throughout the neonatal/juvenile period in rats in parallel with ACTH-inducible steroidogenesis in vitro. We also previously reported that chronic stimulation of rat pups with daily ACTH injections augmented the steroidogenic response of the developing adrenal cortex. We therefore tested the hypotheses that the change in phenotype induced by ACTH was permanent, and that the effects of ACTH were mediated by increased PBR expression. Pups were injected with ACTH or saline from postnatal d (pd) 2-8 or 2-14. Another group of pups received ACTH from pd 2-7, followed by saline from pd 8-14. On the final day, all pups were challenged with a test injection of ACTH or saline. Exposure to ACTH, but not saline, for 1 wk significantly increased adrenal mass, the corticosterone response to ACTH, and the expression of PBR protein and mRNA. Continued ACTH treatment for a second week maintained adrenal mass, steroidogenesis, and PBR mRNA expression. When ACTH was withdrawn after 1 wk and replaced with daily saline injections, however, adrenal mass, ACTH-inducible steroidogenesis, and PBR expression returned to levels comparable to those in age-matched saline controls (i.e. animals that had not received ACTH injections during the first 2 wk). Thus, although ACTH was capable of inducing increased steroidogenic capacity of the juvenile rat adrenal, its effects were only manifest when pups were exposed regularly to high plasma ACTH levels. ACTH, therefore, has significant, but reversible, effects on the development of adrenocortical function, possibly mediated in part by increased expression of PBR.

Adrenal Cortex↗

PubMed2004

Efficacy, safety and pharmacokinetics of palonosetron in patients receiving highly emetogenic cisplatin-based chemotherapy: a dose-ranging clinical study.

BACKGROUND: Although currently available 5-hydroxytryptamine type 3 receptor (5-HT3) antagonists are effective, not all patients receiving these agents achieve adequate control of chemotherapy-induced nausea and vomiting (CINV). Palonosetron, a potent and highly selective 5-HT3 antagonist with a strong affinity for 5-HT3 and a prolonged plasma elimination half-life, may provide a longer duration of action than other approved agents. PATIENTS AND METHODS: One hundred and sixty-one patients were randomly assigned to receive a single intravenous bolus dose of palonosetron (0.3, 1, 3, 10, 30 or 90 microg/kg) before administration of highly emetogenic chemotherapy, with no pretreatment with corticosteroids. RESULTS: The four highest doses of palonosetron were similarly effective during the first 24 h, producing clearly higher complete response (CR) (no emesis, no rescue medication) rates in the 3, 10, 30 and 90 microg/kg groups (46%, 40%, 50% and 46%, respectively) than in the 0.3-1 microg/kg group (24%) of evaluable patients (n = 148). The 3 microg/kg dose was identified as the lowest effective dose. A single dose of palonosetron showed prolonged efficacy in preventing delayed emesis, with approximately one-third of patients who received palonosetron 10 or 30 microg/kg maintaining a CR throughout the 7-day period following chemotherapy administration. Dose-proportional increases in pharmacokinetic parameters and a long plasma half-life (43.7-128 h) were observed. Palonosetron was well-tolerated, with no dose-response effect evident for the incidence or intensity of adverse events. CONCLUSIONS: Palonosetron is an effective and well-tolerated agent for the prevention of CINV following highly emetogenic chemotherapy, with 3 and 10 microg/kg identified as the lowest effective palonosetron doses.

Adult↗

PubMed2003

Efficacy of a targeted, oral penicillin-based yaws control program among children living in rural South America.

Yaws is endemic in rural Guyana. An observational study was conducted to determine the efficacy of oral penicillin V therapy in treating skin lesions of yaws in children. In 1999, inhabitants of 7 rural villages near Bartica, Guyana, were screened for skin lesions of yaws. Cases were confirmed by serological testing. A control program was implemented in 2000: children < or =14 years old were screened, and those with active lesions were treated with oral penicillin V for 7-10 days. In 2001, children were rescreened and active cases were treated. Prevalence of yaws skin lesions fell from 5.1% (52 of 1020 children screened in 2000) to 1.6% (8 of 516 in 2001), a 71% drop. Sixteen (94%) of 17 children treated in 2000 and reassessed in 2001 had complete resolution of lesions. A targeted, oral penicillin-based treatment regimen can successfully treat dermatologic yaws in individual children and can decrease the prevalence of skin yaws in a community in which it is endemic. This information may aid in the implementation of additional control efforts.

Administration, Oral↗

PubMed2002

Randomised, phase II trial comparing oral capecitabine (Xeloda) with paclitaxel in patients with metastatic/advanced breast cancer pretreated with anthracyclines.

Capecitabine, an oral fluoropyrimidine carbamate, was designed to generate 5-fluorouracil preferentially at the tumour site. This randomised, phase II trial evaluated the efficacy and safety of capecitabine or paclitaxel in patients with anthracycline-pretreated metastatic breast cancer. Outpatients with locally advanced and/or metastatic breast cancer whose disease was unresponsive or resistant to anthracycline therapy were randomised to 3-week cycles of intermittent oral capecitabine (1255 mg m(-2) twice daily, days 1-14, (22 patients)) or a reference arm of i.v. paclitaxel (175 mg m(-2), (20 patients)). Two additional patients were initially randomised to continuous capecitabine 666 mg m(-2) twice daily, but this arm was closed following selection of the intermittent schedule for further development. Overall response rate was 36% (95% CI 17-59%) with capecitabine (including three complete responses) and 26% (95% CI 9-51%) with paclitaxel (no complete responses). Median time to disease progression was similar in the two treatment groups (3.0 months with capecitabine, 3.1 months with paclitaxel), as was overall survival (7.6 and 9.4 months, respectively). Paclitaxel was associated with more alopecia, peripheral neuropathy, myalgia and neutropenia, whereas typical capecitabine-related adverse events were diarrhoea, vomiting and hand-foot syndrome. Twenty-three per cent of capecitabine-treated patients and 16% of paclitaxel-treated patients achieved a > or =10% improvement in Karnofsky Performance Status. Oral capecitabine is active in anthracycline-pretreated advanced/metastatic breast cancer and has a favourable safety profile. Furthermore, capecitabine provides a convenient, patient-orientated therapy.

Administration, Oral↗

PubMed2001

Pathobiologic features and prevention of thrombotic complications associated with prosthetic heart valves: fundamental principles and the contribution of platelets and thrombin.

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Blood Platelets↗

PubMed2000

Overcoming Wallstent malposition in the treatment of rectosigmoid obstruction.

In recent years, the use of transanal stenting of malignant colonic strictures for the palliation of obstructive symptoms has increased. Due to the rectosigmoid angle, stenting sigmoid tumors is more troublesome than rectal lesions, but the difficulty may be overcome by using a two-team approach. The radiologist assists the endoscopist with the use of fluoroscopy to ensure proper positioning of both the colonoscope and the stent. The most common complication is stent migration, but stent obstruction and colonic perforation may also occur. We treated a woman suffering from metastatic gastric cancer with peritoneal metastases by creating a 12-cm stricture in the sigmoid colon. Two adjoining Wallstents were required to bridge the obstruction. Following migration of the proximal stent, a third stent was introduced to bridge the previous two stents with satisfactory outcome.

Colon, Sigmoid↗

PubMed2000

Bedside measurement of D-dimer in the identification of bacteremia in the emergency department.

The objective of this pilot study was to determine the clinical utility of the SimpliRed D-dimer bedside assay to identify patients with bacteremia in a university hospital Emergency Department. We tested 265 patients and compared blood culture results with a novel D-dimer semiquantitative whole blood assay. Bacteremia was confirmed in 25/262 patients. Sensitivity of D-dimer assay was 66.7% for Gram-positive bacteremia and 61.5% for Gram-negative bacteremia with negative predictive value of 98% for Gram-positive and 96% for Gram-negative bacteremia patients. Measurement of D-dimer appears to be of value in identifying patients at low risk for bacteremia and can be accomplished rapidly using a whole blood semiquantitative bedside assay. Although increases in D-dimer are not detected in all patients subsequently documented to have bacteremia on a single sampling, the results of this and other earlier studies suggest assay of D-dimer is useful in rapid differentiation of patients with bacteremia from those who have no bacteremia using blood culture positivity as the standard for bacteremia.

Adult↗

PubMed2000

Prevalence and significance of gallbladder abnormalities seen on sonography in intensive care unit patients.

OBJECTIVE: We evaluated sonographic abnormalities of the gallbladder other than acalculous cholecystitis across a broad range of intensive care unit (ICU) patients. SUBJECTS AND METHODS: Fifty-five consecutive patients (age range, 18-94 years old; mean age, 56 years; 33 men, 22 women), who were admitted to the ICU with a variety of diagnoses, underwent sonography of the gallbladder twice a week. Patients with gallbladder calculi were excluded from the study. The gallbladder was examined for the recognized sonographic features of acalculous cholecystitis: gallbladder wall thickening, gallbladder distention, intramural gallbladder lucencies (striated gallbladder wall), pericholecystic fluid, gallbladder sludge, and Murphy's sign. These findings were correlated with clinical and laboratory parameters that are associated with acalculous cholecystitis: fever, WBC, liver function tests, levels of serum bilirubin, mechanical ventilation status, and administration of parenteral nutrition, narcotic analgesics, antibiotics, and pressor agents. RESULTS: Eleven of the 55 patients were found to have gallbladder calculi and were excluded from the study. Thirty-seven (84%) of the remaining 44 patients had at least one sonographic abnormality while in the ICU. Twenty-five (57%) of the 44 patients had as many as three abnormalities found on sonography, and six (14%) of 44 patients had four or five sonographic findings of gallbladder abnormalities while in the ICU. No statistically significant correlation was found among any of these sonographic abnormalities and the clinical and laboratory parameters. CONCLUSION: Gallbladder abnormalities are frequently seen on sonography in ICU patients, even if these patients are not suspected of having acalculous cholecystitis; therefore, sonography appears to be of limited value in diagnosing acalculous cholecystitis in ICU patients.

Adolescent↗

PubMed1999

A randomized, multicenter trial of weight-adjusted intravenous heparin dose titration and point-of-care coagulation monitoring in hospitalized patients with active thromboembolic disease. Antithrombotic Therapy Consortium Investigators.

BACKGROUND: Therapy with intravenous unfractionated heparin improves clinical outcome in patients with active thromboembolic disease, but achieving and maintaining a therapeutic level of anticoagulation remains a major challenge for clinicians. METHODS: A total of 113 patients requiring heparin for at least 48 hours were randomly assigned at 7 medical centers to either weight-adjusted or non-weight-adjusted dose titration. They were separately assigned to either laboratory-based or point-of-care (bedside) coagulation monitoring. RESULTS: Weight-adjusted heparin dosing yielded a higher mean activated partial thromboplastin time (aPTT) value 6 hours after treatment initiation than non-weight-adjusted dosing (99.9 vs 78.8 seconds; P =.002) and reduced the time required to exceed a minimum threshold (aPTT >45 seconds) of anticoagulation (10.5 vs 8.6 hours; P =.002). Point-of-care coagulation monitoring significantly reduced the time from blood sample acquisition to a heparin infusion adjustment (0.4 vs 1.6 hours; P <.0001) and to reach the therapeutic aPTT range (51 to 80 seconds) (16.1 vs 19.4 hours; P =.24) compared with laboratory monitoring. Although a majority of patients participating in the study surpassed the minimum threshold of anticoagulation within the first 12 hours and reached the target aPTT within 24 hours, maintaining the aPTT within the therapeutic range was relatively uncommon (on average 30% of the overall study period) and did not differ between treatment or monitoring strategies. CONCLUSIONS: Weight-adjusted heparin dosing according to a standardized titration nomogram combined with point-of-care coagulation monitoring using the BMC Coaguchek Plus System represents an effective and widely generalizable strategy for managing patients with thromboembolic disease that fosters the rapid achievement of a desired range of anticoagulation. Additional work is needed, however, to improve on existing patient-specific strategies that can more effectively sustain a therapeutic state of anticoagulation.

Adult↗

PubMed1999

Regional leptin kinetics in humans.

BACKGROUND: Leptin is known to be cleared by the kidney, a tissue with substantial leptin receptor mRNA expression; however, lung, liver, and muscle tissues also express leptin receptor messenger RNA and it is not known whether these tissues also clear leptin from the circulation. OBJECTIVE: This study was conducted to determine whether net leptin clearance takes place in the pulmonary, splanchnic, and leg tissue beds to a similar extent as in the kidney. DESIGN: Plasma leptin concentrations were measured in blood entering and exiting the renal bed, pulmonary bed, splanchnic bed, and leg in 4 groups of subjects. Regional plasma flow was measured in 3 of the 4 groups. RESULTS: Renal leptin uptake was substantial, whereas no net uptake of leptin by the splanchnic or pulmonary vascular beds was detected; leg tissue was a net leptin producer. Net leptin release by leg tissue, relative to leg adipose tissue mass, was comparable with that reported previously for abdominal subcutaneous adipose tissue. CONCLUSION: These results confirm that the kidney is a significant site of leptin clearance in humans, whereas pulmonary and splanchnic beds are not.

Absorptiometry, Photon↗

PubMed1999

Tissue factor pathway inhibitor attenuates procoagulant activity and upregulation of tissue factor at the site of balloon-induced arterial injury in pigs.

Intravenous infusion of recombinant tissue factor pathway inhibitor (rTFPI) for 24 hours decreases neointimal thickening and luminal stenosis 1 month after balloon-induced injury to the carotid arteries in minipigs. This study was designed to determine whether the effect of rTFPI is accounted for by early decreases in procoagulant activity and thrombosis on the injured vessel wall. Vascular injury was induced by balloon hyperinflations in both carotid arteries of anesthetized pigs given no anticoagulant as a control (n=16), an intravenous infusion for 24 hours of rTFPI (0.5 mg/kg bolus and 25 microg. kg(-1). min(-1), n=14), or an intravenous infusion of unfractionated heparin (100 U. kg(-1). h(-1), n=19). Accumulation of radiolabeled autologous platelets was markedly decreased over 24 hours on injured arteries from animals given rTFPI (0.6x10(6)/cm(2)) compared with controls (2.5x10(6)/cm(2), P=0.0004). Deposition of radiolabeled fibrin was also decreased in rTFPI-treated animals (269+/-266 microg/cm(2)) compared with controls (2389+/-1673 microg/cm(2), P=0.04). Similar effects were observed with heparin. However, factor Xa activity, assayed after 24 hours by incubation of the injured arterial segments with the chromogenic substrate S-2222, was decreased more markedly on arteries from rTFPI-treated animals (0.14+/-0.13 OD) than those from heparin-treated animals (0.29+/-0.18 OD) compared with controls (0. 47+/-0.24 OD, P=0.0007). In addition, arteries from rTFPI-treated animals showed a 4-fold lower induction of tissue factor protein compared with controls (P=0.0002). Attenuation of procoagulant activity and tissue factor-mediated thrombin generation in response to injury may account for the promising results with rTFPI in the porcine angioplasty model.

Animals↗

PubMed1999

Multicenter, phase II trial of exemestane as third-line hormonal therapy of postmenopausal women with metastatic breast cancer. Aromasin Study Group.

PURPOSE: To assess the antitumor activity, safety, and hormone-suppressive effects of the irreversible aromatase inactivator, exemestane (Aromasin, Pharmacia & Upjohn, Kalamazoo, MI), administered as third-line hormone therapy to postmenopausal women with metastatic breast cancer that is refractory to tamoxifen and megestrol acetate. PATIENTS AND METHODS: Exemestane was administered at a dose of 25 mg/d orally until patients experienced disease progression. The efficacy and safety of exemestane were clinically and radiographically evaluated. The impact of exemestane treatment on tumor-related signs and symptoms was assessed. The effect of exemestane on serum levels of estrogens and other steroidal hormones was determined. RESULTS: Ninety-one patients were treated. There were four complete responses (CR) and eight partial responses (PR), for an objective response rate of 13% in the entire treated population. The overall success rate (CR, PR, or stable disease [SD] >/= 24 weeks) was 30%. The median duration of response and overall success was 9 months and 8 months, respectively. Most patients with CR/PR (83%; 10 of 12 patients) and SD >/= 24 weeks (80%; 12 of 15 patients) had improved or stable tumor-related signs and symptoms. Mean levels of circulating estrone (E(1)), estradiol (E(2)), and estrone sulfate decreased to 11%, 22%, and 13% of baseline levels, respectively (at week 8 or 16 of treatment). One half of the patients had undetectable E(1) and E(2) levels during treatment, including at the time of disease progression. Mild nausea (20% of patients) and hot flashes (20%) were the most common drug-related adverse events and were generally grade 1. CONCLUSION: Exemestane is an active and well-tolerated third-line hormonal therapy that represents a new treatment option for postmenopausal patients with advanced breast cancer that has become refractory to standard first- and second-line hormonal therapies.

Adult↗

PubMed1996

Antiemetic efficacy of two different single intravenous doses of dolasetron in patients receiving high-dose cisplatin-containing chemotherapy.

This randomized, double-blind, parallel-group, multicenter study compared the antiemetic effectiveness, safety, and tolerability of two different intravenous (i.v.) doses of dolasetron mesylate (0.6 and 1.8 mg/kg) in cancer patients receiving their first course of high-dose cisplatin-containing chemotherapy (> or = 75 mg/m2). Efficacy was assessed by recording the timing, number, and severity of emetic episodes in the 24 h following high-dose cisplatin. Safety was evaluated by monitoring adverse events, vital signs, clinical laboratory parameters, and electrocardiograms. Of the 62 patients enrolled in the study, 29 received 0.6 mg/kg of dolasetron mesylate and 33 received 1.8 mg/kg. Patients who received dolasetron mesylate 1.8 mg/kg consistently experienced a greater degree of antiemetic control than those who received 0.6 mg/kg. Complete responses were achieved by 55% of patients who received 1.8 mg/kg compared with 31% for the 0.6-mg/kg group. The 1.8-mg/kg group achieved a significantly (p = 0.039) higher complete/ major response rate than the 0.6-mg/kg group (77% vs 55%, respectively) and a significantly (p = 0.004) longer time to the first emetic episode (> 24 h vs 13.5 h, respectively). More than 80% of patients were either satisfied or very satisfied with dolasetron treatment. The most common adverse events were mild to moderate in intensity, consistent with other studies, and included headache (24.1% of patients) and diarrhea (4.8%). These results demonstrated that a single 1.8-mg/kg i.v. dose of dolasetron mesylate provided effective antiemetic activity in a majority of patients given high-dose cisplatin for the first time and should be evaluated further in clinical trials.

Antiemetics↗

PubMed1996

The ABCs of TPN.

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Nutrition Assessment↗

PubMed1996

QI study in the ICU: bedside testing of gastric contents.

Quality improvement (QI) studies must use valid and reliable tools to measure patient outcomes. This study identified daily nursing practices related to the prevention of stress ulcer syndrome (SUS) in a medical intensive care unit (ICU). The QI study: (1) compared the "gold" standard bedside test for gastric pH and fecal occult blood with an inclusive measurement tool that was created specifically to measure gastric pH and occult blood at the bedside; (2) assessed nursing knowledge of SUS; and (3) analyzed cost.

Clinical Nursing Research↗

PubMed1995

Phase II trial of docetaxel in advanced anthracycline-resistant or anthracenedione-resistant breast cancer.

PURPOSE: The purpose of this study was to evaluate the clinical efficacy and safety of docetaxel in patients with metastatic breast cancer (MBC) resistant to doxorubicin or mitoxantrone. PATIENTS AND METHODS: Docetaxel 100 mg/m2 was administered as a 1-hour intravenous (IV) infusion every 3 weeks to 42 patients registered at four centers. Patients must have received at least one but no more than two prior chemotherapy regimens for MBC (in addition to any prior adjuvant therapy). One of the regimens for metastatic breast cancer must have included an anthracycline or anthracenedione and the cancer must have progressed on that regimen. RESULTS: Objective responses were seen in 20 of 35 assessable patients (three complete responses [CRs] and 17 partial responses [PRs]), for an objective response rate of 57% (95% confidence interval [CI], 39% to 74%) and in 21 of 42 registered patients (50% response rate [RR]; 95% CI, 34% to 66%) entered onto the trial. The median response duration was 28 weeks. The most common toxicity in this study was grade 4 neutropenia, which occurred in 95% of patients. Other clinically significant nonhematologic side effects included stomatitis, skin reactions, neurosensory changes, asthenia, and fluid retention. Patients who received dexamethasone premedication had a later onset of fluid retention than those who did not receive dexamethasone (onset at a median cumulative docetaxel dose of 503 mg/m2 and 291 mg/m2, respectively). CONCLUSION: Docetaxel at this dose and schedule has a high level of antitumor activity in patients with treatment-refractory advanced breast cancer, and appears to be one of the most active agents for the treatment of this patient population.

Adult↗

PubMed1993

Amonafide treatment of refractory esophageal cancer. A Southwest Oncology Group study.

Amonafide, a synthetic benzisoquinolinedione, was evaluated for treatment of squamous esophageal cancer. Eleven men and 5 women were eligible with a median performance status of 1 and median age of 63 years. Six had no prior treatment. All patients had measurable disease. Therapy consisted of amonafide 300 mg/m2d days 1-5 every 21 days. Thirty-five courses of therapy were delivered. The median number of courses received was two. Sixteen patients are evaluable for toxicity. Thirteen are evaluable for response. Toxicity was severe. Seven patients were hospitalized for toxicity. Six patients had grade IV granulocytopenia; two, grade IV thrombocytopenia. Angioedema developed in one patient; severe exfoliative dermatitis in another. A single partial response, with the decrease in size a supraclavicular node, was noted in a previously untreated patient. Amonafide, in this dose and schedule, is associated with occasionally severe toxicity precluding its likely use in squamous cell esophageal carcinoma.

Adenine↗

PubMed1993

The significance of enteral nutrition in the intensive care unit patient.

The gut and its nonimmunologic and immunologic barriers have an important role in the survival of critically ill patients. Burns, hemorrhagic shock, intestinal obstruction, protein-calorie malnutrition, and several therapies (e.g., parenteral nutrition, steroids), used in critically ill patients are known to promote the breakdown of the mucosal barrier and to permit translocation of intestinal pathogens. Enteral nutrition, in conjunction with the use of certain immunostimulatory nutrients, can now be used to prevent or minimize damage to the mucosal barrier and to enhance its immunologic function in critically ill patients.

Critical Illness↗