Biomedical subjects

N L Seibel

Publications and source records attributed to N L Seibel.

7 recordsLinked to original sources

PubMed1992

Safety and pharmacokinetics of fluconazole in children with neoplastic diseases.

To evaluate the safety, tolerance, and pharmacokinetics of fluconazole in children with neoplastic diseases, we studied fluconazole in 26 children, aged 5 to 15 years, with normal renal function who were receiving treatment for cancer. The patients received fluconazole, 2, 4, or 8 mg/kg per day for 7 days intravenously for a 2-hour period. Patients had no nausea or vomiting related to fluconazole; three patients had an asymptomatic rise in hepatic aminotransferase values after four to six doses (one patient at 2 mg/kg per day and two patients at 8 mg/kg per day), which returned to normal within 2 weeks after discontinuation of the drug. Fluconazole showed linear first-order kinetics over the dosage range tested and during multiple dosing. After the first dose, mean clearance was 22.8 +/- 2.3 ml/min, volume of distribution 0.87 +/- 0.06 L/kg, and terminal elimination half-life 16.8 +/- 1.1 hours. Similarly, after the last dose, clearance was 19.4 +/- 1.3 ml/min, volume of distribution 0.84 +/- 0.04 L/kg, and terminal elimination half-life 18.1 +/- 1.2 hours. Patients receiving their first fluconazole dose of 8 mg/kg achieved peak serum levels of 9.5 +/- 0.4 microgram/ml and trough levels of 2.7 +/- 0.5 microgram/ml 24 hours later, and an area under the serum concentration-time curve from time zero to infinity of 186 +/- 16 micrograms.hr per milliliter. Renal clearance of fluconazole was 65% +/- 5% of total clearance and demonstrated the predominantly renal excretion of this drug. We suggest that the shorter serum half-life and the higher frequency of aminotransferase elevations in comparison with those of adults warrant careful investigation of fluconazole in controlled clinical trials.

Child↗

PubMed1992

Phase II study of liposomal muramyl tripeptide in osteosarcoma: the cytokine cascade and monocyte activation following administration.

PURPOSE: A phase II trial that uses liposome-encapsulated muramyl tripeptide phosphatidylethanolamine (L-MTP-PE) in patients with relapsed osteosarcoma is underway. To determine if in vivo cytokine induction plays a role in the mechanism of action of L-MTP-PE, we investigated the circulating cytokine levels of 16 patients who were undergoing therapy. PATIENTS AND METHODS: Patients had histologically proven osteosarcoma and pulmonary metastases that developed either during adjuvant chemotherapy or that were present at diagnosis and persisted despite chemotherapy. Patients were rendered disease-free by surgery. The major goal of the study was to improve the disease-free interval in this high-risk group. L-MTP-PE 2 mg/m2 was infused during a 1-hour period twice a week for 12 weeks, then once a week for 12 weeks. Serial blood samples were collected after L-MTP-PE administration and were assayed for cytokine levels (tumor necrosis factor-alpha [TNF alpha] interleukin-1 alpha [IL-1 alpha], IL-1 beta, IL-6, interferon-gamma [IFN-gamma], neopterin, C-reactive protein). RESULTS: After the infusion of L-MTP-PE, there was rapid induction of circulating TNF alpha and IL-6. TNF alpha levels peaked 1 to 2 hours after infusion in 10 of 16 patients, whereas peak IL-6 levels were detected at 2 to 3 hours in all patients. Induction of circulating TNF alpha and IL-6 was evident only after the first dose of L-MTP-PE. Neither IL-1 alpha nor IL-1 beta was detected in the plasma. Neopterin levels increased at 24 hours postinfusion, which indicated macrophage activation, and were not related to the induction of circulating IFN-gamma. C-reactive protein was elevated in all patients at 24 hours and decreased by 72 hours. Unlike circulating TNF alpha and IL-6, elevations in C-reactive protein and neopterin could be detected throughout the treatment course. CONCLUSION: It is concluded that L-MTP-PE has specific biologic effects in patients with osteosarcoma that may be important to the drug's immunostimulatory capacity and its effectiveness as an antitumor agent.

Acetylmuramyl-Alanyl-Isoglutamine↗

PubMed1991

Lack of association between neutropenia and the incidence of bacteremia associated with indwelling central venous catheters in febrile pediatric cancer patients.

To assess the incidence of bacteremia in pediatric cancer patients with indwelling central venous catheters with fever, we reviewed the records of all 67 such patients sequentially admitted during a 10-month period at our institution. There were a total of 140 episodes of fever in these 67 patients. In 55 of the episodes (39%) patients were nonneutropenic (absolute neutrophil count, greater than 500/mm3); 85 episodes (61%) were associated with neutropenia. Twenty-four percent of all episodes of fever in nonneutropenic patients were related to bacteremia vs. 9.5% of episodes of fever in the presence of neutropenia (P less than 0.05). When clinical evidence of an exit site infection was absent, the incidence of bacteremia in the neutropenic and nonneutropenic groups was similar (11% in the neutropenic group; 10% in the nonneutropenic group). We conclude that bacteremia is frequently observed in febrile pediatric cancer patients with indwelling venous catheters who are not neutropenic, particularly if there is clinical evidence of an exit site infection. Thus empiric antibiotic therapy is warranted in all pediatric oncology patients with indwelling catheters who develop fever.

Adolescent↗

PubMed1989

Tumor detection through the use of immunoglobulin gene rearrangements combined with tissue in situ hybridization.

Leukemias and lymphomas can now be classified according to the particular immunoglobulin, T-cell receptor, or growth-affecting genes they are expressing. Recognition of the structural alterations of lymphoid DNA has been used to identify neoplasms of previously uncertain lineage, to aid in diagnosis, and to define the state of differentiation of the neoplasm. We have developed a procedurally simple, rapid turnaround technique for using tumor-specific gene alterations as tumor-specific markers. Probes can be constructed that will recognize only the gene expressed in the tumor and not those in any of the normal cells when used with tissue in situ hybridization. We demonstrate the application of direct sequencing of a specific gene of interest from total RNA from a patient with multiple myeloma. A probe is then generated from this sequence and applied directly to patient material.

Base Sequence↗

PubMed1988

Detection of genes of interest in tissues and cells by in situ hybridization.

In situ hybridization (ISH) is a powerful technique for assessing the expression of particular genes of interest within individual cells in tissues or cytospins. The only limitations of the technique are the availability of appropriate probes and tissues. When coupled with routine histology and DNA analysis, characterization and classification of tissues can be greatly extended. Future applications include the identification of tumor-specific markers that can be combined with ISH in diagnostic strategies.

Animals↗

PubMed1988

A study of myc-related gene expression in small cell lung cancer by in situ hybridization.

The expression of myc-related genes (c-myc, N-myc, and L-myc) in small cell lung cancer (SCLC) was studied by RNA-RNA tissue in situ hybridization. The tissues investigated included cytospins of ten cell lines derived from patients with SCLC, four corresponding nude mouse xenografts from cell lines, and metastatic tumor tissue obtained by surgical biopsy and at autopsy. The probes were prepared as 35S labeled complementary RNA. The expression of each gene was demonstrated specifically by autoradiography in the cytoplasm of the neoplastic cell samples. The average levels of oncogene expression in each specimen corroborated previous data obtained by Northern blot assays. In addition, heterogeneity in gene expression from cell to cell in each sample was noted. This study represents the first attempt to demonstrate oncogene expression in lung cancer cell lines and tissues in situ, and confirms that the expression of these myc related genes can be seen in the primary tumor. The technique of RNA-RNA tissue in situ hybridization has great potential in answering fundamental questions of tumor cell heterogeneity and progression in SCLC. It should be useful in both prospective and retrospective studies.

Carcinoma, Small Cell↗

PubMed1978

Hematology problem.

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Anemia, Hemolytic, Autoimmune↗