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Biomedical subjects

S Gilbertson

Publications and source records attributed to S Gilbertson.

7 recordsLinked to original sources

Pulse duration measurements of grazing-incidence-pumped high repetition rate Ni-like Ag and Cd transient soft x-ray lasers.

We have measured the pulse duration of gain-saturated 13.9 nm Ni-like Ag and 13.2 nm Ni-like Cd transient collisional lasers excited by grazing-incidence-pumping for several pumping conditions. High-resolution streak-camera measurements yielded FWHM pulse durations close to 5 ps for both lasers under optimum pumping conditions. The very high brightness and short pulse duration of these new high repetition tabletop soft x-ray lasers make them an attractive source for dynamic applications.

Journal Article↗

Merging pathways: music therapy in neurosurgical rehabilitation.

Relatively few departments of Music Therapy are found within neurosurgical rehabilitation clinics. In institutions where these departments exist, music therapy has become an integral part of multi-professional treatment and research activities (Gilbertson 1999). The diverse intervention strategies in Music Therapy focus upon auditory, motor, visual, cognitive and affective processing which are all involved in receptive and expressive musical behaviour and which affect related non-musical behaviour. A clear differentiation is made between primary and adjunct therapy roles. The related fields of neuromusicology, neuroanatomy, neuropsychology, music psychology and humanistic psychology are primary sources in the development of models of clinical application (Hodges 1996). Our main interests are focussed on the following issues and areas of clinical application: The initialisation of contact with patients in vegetative status Communicative interaction with patients who can not (initially) use verbal communication (aphasic disorders) Temporal motor organisation with patients with sensomotor disorders Cognitive organisation and mnemonic framework with patients with neuropsychological functional disorders (concentration, memory, perception) Treatment of spatial perception disorders (neglect) Enhancing personal and social integration following individual isolation, social withdrawal. These topics will be discussed and highlighted with clinical examples.

Humans↗

A totally implanted injection port system for blood sampling and chemotherapy administration.

We evaluated a totally implanted system consisting of a subcutaneous injection port connected to a silicone elastomer central venous catheter for vascular access, including blood drawing, in 35 patients with cancer. All patients lacked peripheral venous access sites and were undergoing aggressive chemotherapy programs. The cumulative duration of successful access exceeded 2,900 days (for individual patients: range, five to 203 days; median, 61 days). In no instance were infusions or injections unsuccessful. Blood-sampling attempts were successful 90% of the time. The system did not require flushing between uses, being filled with heparinized saline after each entry. There were no instances of irreversible catheter occlusion or shear and no system-related infections. Thus, this device appears to have advantages over other central venous catheters in terms of patient acceptance and lack of maintenance between uses.

Adolescent↗

Constant intraperitoneal 5-fluorouracil infusion through a totally implanted system.

Five-day continuous intraperitoneal (ip) infusions of 5-fluorouracil (FU) were injected into five patients as part of a phase I clinical pharmacology study. They received 20 courses through a totally implanted catheter/injection port system. Six courses are evaluable for kinetic parameters and all courses are evaluable for toxicity. In each course a 2 to 3 log FU concentration differential in favor of the peritoneal cavity was achieved and maintained. Steady-state venous plasma FU concentrations averaged 0.34 microM, whereas steady-state ip FU concentrations averaged 697 microM. Mean total body clearance (TBC) in these patients was 18.4 l/min and mean permeability-area (PA) product for diffusion from the peritoneum was 13.7 ml/min. Mean TBC of 20 l/min with ip FU infusion was observed in one patient who also received a 24-hr IV FU infusion for comparison. The TBC during the later infusion was 5.9 l/min. In this patient, calculations indicate 75% extraction of drug during the passage from the peritoneum to the systemic circulation, presumably representing in large part hepatic extraction of FU taken into the portal venous circulation. Ip constant infusion and bolus kinetics were compared in one patient. TBC for the ip bolus was 14.3 l/min, which was approximately half of the TBC of 29.5 l/min determined during the 5-day constant ip infusion. Thus constant ip infusion of FU (l gm/day) can provide an improved regional advantage over bolus ip FU because of an increased TBC. Toxicity was acceptable in all courses. Dose limiting toxicity was regional, namely moderate chemical peritonitis seen in two of the five patients on repeated courses. There was no myelosuppression, alopecia, nausea, or vomiting.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Hepatic arterial streptozocin: a clinical pharmacologic study in patients with liver tumors.

Hepatic arterial infusions of streptozocin (STZ) were compared with peripheral venous infusions administered for 3 h at a dose rate of 0.5 or 1.0 g/m2 . h in five patients with liver-predominant neoplastic disease. Peripheral venous plasma STZ levels were measured during and for 3 h after completion of all infusions. Steady-state was achieved at 2 h and the elimination half-life was 35-40 min, the total body clearance was 400 ml/min, and the volume of distribution of STZ was 20-22 liters in these patients. Comparison of steady-state drug levels demonstrated minimal hepatic extraction (mean 5%). Assuming a hepatic arterial blood flow of 100-200 ml/min with a total body clearance of 400 ml/min, hepatic arterial administration of STZ can be expected to result in a three- to sixfold greater exposure of tumor in the liver compared with the intravenous route. Toxicity was minimal and two patients had evidence of response.

Adult↗

Induction of leukemia-associated inhibitory activity and bone marrow granulocyte-macrophage progenitor cell alterations during infection with Abelson virus.

Neonatal and adult BALB/c mice were investigated in a longitudinal study for the acquisition of leukemia-associated inhibitory activity (LIA) interactions after inoculation with Abelson virus in vivo. Within 2 to 4 days after virus infection, the granulocyte-macrophage colony-forming cells from the bone marrow and spleen of the infected mice became insensitive to inhibition by LIA, even though colony morphology appeared normal. Shortly after, or simultaneously with, the detection of the colony-forming cell resistance phenomenon, LIA was found in bone marrow, spleen, and thymus cells. The abnormal interactions appeared to be related to induction of lymphoma in BALB/c neonates and to a lymphoproliferative disease in adult BALB/c mice. In contrast, normal cellular interactions were noted in adult C57BL/6 mice which were not susceptible to the Abelson disease after virus inoculation and in untreated neonatal and adult BALB/c and adult C57BL/6 mice. Their colony-forming cells were sensitive to inhibition by LIA, and no LIA was detected in their bone marrow, spleen, and thymus cells. The abnormal cellular interactions are similar to those noted in human leukemia, lymphoma, and "preleukemia." This suggests that Abelson virus-infected mice can serve as a model for the study of LIA interactions.

Abelson murine leukemia virus↗