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Biomedical subjects

E Campbell

Publications and source records attributed to E Campbell.

At least 73 records · Page 4Linked to original sources
PubMed1995

Inadequacy of visual alarms in helicopter air medical transport.

BACKGROUND: Air medical programs use medical equipment primarily designed for hospital and/or ground transport settings. Many of these medical devices are equipped with auditory alarms of malfunction or deteriorating clinical status. The high ambient noise requires visual scanning of medical devices to detect alarm conditions in the helicopter cabin. PURPOSE: To evaluate the adequacy of visual scanning for alarm conditions in the helicopter air medical environment. METHODS: The helicopter transport program used in this study is staffed with two medical crewmembers. Flight nurse response time (RT) to a visual alarm was assessed during 25 air medical patient flights. RT was measured using a battery powered dual timer device with a red LED visual alarm placed in a fixed position among the medical instruments. The device was activated at a random time point unknown to the medical crew during each patient flight. RT was defined as the elapsed time from activation of the alarm until it was physically switched off by the flight nurse. RESULTS: RT was surprisingly lengthy for the study population with a mean RT of 81.2 +/- 78.4 s (95% CI 48.8-113.5 s). The variability of RT was also surprising ranging from 3 s to > 5 min. CONCLUSION: RT to visual alarms in the air medical environment is lengthy and quite variable. Recognition of malfunction of medical equipment or early signs of clinical instability prior to clinical deterioration cannot be assured by visual scanning for alarm conditions. Alternative alarming systems should be considered and investigated for air medical transport.

Air Ambulances↗
PubMed1995

Glomerulonephritis after ventriculo-atrial shunt.

We describe five patients with glomerulonephritis (GN) associated with cerebrospinal fluid shunt insertion to relieve hydrocephalus. A ventriculo-atrial (V-A) shunt had been placed on average 12.5 years prior to the diagnosis of nephritis (range 0.5-21 years). Four patients developed membranoproliferative glomerulonephritis (MPGN) with associated hypocomplementaemia. A single patient developed focal proliferative glomerulonephritis. Coagulase-negative staphylococci were cultured in four patients, either from blood or from the shunt. Four patients had their shunts removed, two of whom also received antibiotics. The other patient received antibiotics alone for infective endocarditis due to staphylococcal bacteraemia which originated in the shunt. All patients had substantial renal impairment at the time of diagnosis (GFR, glomerular filtration rate, 20-45 ml/min). There was significant improvement in renal function after appropriate treatment; four of the five patients doubled their GFRs and two patients regained normal function.

Adolescent↗
PubMed1994

Loin pain-hematuria syndrome: how effective is renal autotransplantation in its treatment?

OBJECTIVES: To evaluate our experience with renal autotransplantation in the management of loin pain-hematuria (LPH) syndrome after relatively long follow-up (30 to 35 months). METHODS: Four patients with LPH syndrome of 3 to 18 years' duration underwent technically successful autotransplantation. All patients preoperatively had normal radiologic investigations, including renal arteriography and biopsy. All required narcotic analgesia for pain control. Patients were followed for 30 to 35 months. RESULTS: All 4 patients were pain and narcotic free for 6 months postoperatively. At 18 months after surgery, 3 of the 4 had recurrence of the pain and at 30 months, 2 required nephrectomy. Only 1 patient of 4 had sustained pain relief at 35 months. CONCLUSIONS: Renal autotransplantation certainly offers temporary relief from LPH syndrome, but in our experience this was not durable in the majority of our patients.

Adult↗
PubMed1994

A phase II trial of DaunoXome, liposome-encapsulated daunorubicin, in patients with metastatic adenocarcinoma of the colon.

CONTEXT: Liposomal encapsulation of drugs can potentially ameliorate toxicities and improve acute and chronic tolerance. The increased uptake of liposomes by colon adenocarcinoma cell lines may enable DaunoXome to circumvent the p-glycoprotein-mediated anthracycline resistance of colon cancer cells. PURPOSE: To determine if DaunoXome, liposome-encapsulated daunorubicin, has clinical activity in patients with adenocarcinoma of the colon who failed treatment with a 5-fluorouracil containing regimen. METHOD: In a Phase II trial, patients with metastatic adenocarcinoma of the colon, whose disease has progressed after receiving one 5-fluorouracil-containing regimen, were treated with DaunoXome 100 mg/m2 repeated every 3 weeks. RESULTS: In this trial 16 patients received 45 courses of therapy. No objective tumor responses were seen. Hematologic toxicities consisted of neutropenia (grade 3 and 4), grade 2 anemia, and grade 2 thrombocytopenia. Nonhematologic toxicities were mild and manageable. Of the 16 patients, 5 experienced flushing, shortness of breath, chest tightness, and back pain during DaunoXome infusion, which resolved with infusion interruption, diphenhydramine, and meperidine. CONCLUSIONS: DaunoXome is generally well tolerated at a dose of 100 mg/m2 every 3 weeks. Toxicities are mild and reversible. On this schedule DaunoXome does not have significant clinical activity in patients with metastatic adenocarcinoma of the colon who have progressed after one 5-fluorouracil-containing regimen.

Adenocarcinoma↗
PubMed1993

Humanized Mik beta 1, a humanized antibody to the IL-2 receptor beta-chain that acts synergistically with humanized anti-TAC.

Mik beta 1 is a mouse mAb directed at the beta-subunit of the human IL-2R (Tac) that inhibits IL-2 binding and inhibits IL-2 induction of large granular lymphocytes (LGL). Mik beta 1 alone does not inhibit IL-2-induced T-cell proliferation, but acts synergistically with anti-Tac to inhibit IL-2-induced proliferation of activated T cells. To evaluate these effects for possible therapy in humans, we constructed two humanized Mik beta 1 antibodies by combining the complementarity-determining regions of the murine antibody with human framework and constant regions. Compared with murine Mik beta 1, the two humanized Mik beta 1 antibodies, which differ in their degree of humanization, had similar affinities for IL-2R beta. The murine Mik beta 1 and one of the humanized Mik beta 1 antibodies were equivalent in competing for IL-2 binding to IL-2R beta and inhibiting IL-2 induction of LGL cytotoxicity. The activity of the second humanized antibody was significantly reduced. The three Mik beta 1 antibodies act synergistically to varying degrees with humanized anti-Tac to prevent IL-2-induced proliferation of activated T cells. This capacity to synergize paralleled their abilities to inhibit IL-2 binding. In addition, both humanized antibodies directed antibody-dependent cell-mediated cytotoxicity. We hope that humanized Mik beta 1 in combination with humanized anti-Tac will provide a new immunosuppressive therapy for the treatment of autoimmune diseases, graft-versus-host disease, and prevention of allograft rejection.

Amino Acid Sequence↗
PubMed1993

Low-frequency chimeric yeast artificial chromosome libraries from flow-sorted human chromosomes 16 and 21.

Construction of chromosome-specific yeast artificial chromosome (YAC) libraries from sorted chromosomes was undertaken (i) to eliminate drawbacks associated with first-generation total genomic YAC libraries, such as the high frequency of chimeric YACs, and (ii) to provide an alternative method for generating chromosome-specific YAC libraries in addition to isolating such collections from a total genomic library. Chromosome-specific YAC libraries highly enriched for human chromosomes 16 and 21 were constructed. By maximizing the percentage of fragments with two ligatable ends and performing yeast transformations with less than saturating amounts of DNA in the presence of carrier DNA, YAC libraries with a low percentage of chimeric clones were obtained. The smaller number of YAC clones in these chromosome-specific libraries reduces the effort involved in PCR-based screening and allows hybridization methods to be a manageable screening approach.

Cell Fractionation↗
PubMed1993

Activity of deep dorsal horn neurons in the anaesthetized rat during hyperalgesia of the hindpaw induced by ultraviolet irradiation.

Thermal hyperalgesia was induced by UV irradiation of the glabrous skin of the hindpaw of adult female Sprague-Dawley rats. We have recorded single cell activity and studied excitability changes in wide dynamic range neurons in the lumbar spinal segments during the early phase (days 1-3) and late phase (days 5-7) of thermal hyperalgesia in animals under urethane anaesthesia. The proportion of spontaneously active wide dynamic range cells was increased following UV irradiation and the degree of spontaneous activity was enhanced during the course of hyperalgesia. In addition there was a significant increase in the total number of spikes evoked by standardized mechanical and noxious heat stimuli when tested at days 1-3 and days 5-7. The duration of the evoked responses was also significantly prolonged in both UV-treated groups. The noxious temperature threshold to radiant heat stimulation was significantly decreased on the UV-treated but not on the contralateral hindpaw. The average size of the receptive fields on the UV-treated paws was expanded in comparison to control. To differentiate between possible central and peripheral components of the hyperactivity of wide dynamic range cells we performed in situ dorsal rhizotomy during the recording. Cutting the dorsal roots (L2-5) evoked a significantly larger and more prolonged discharge in wide dynamic range cells in both UV-treated groups in comparison to control. Spontaneous activity in spinal wide dynamic range neurons was reduced after rhizotomy in each group. However, the decrease was only significant at days 1-3 (P < 0.05) but not at days 5-7.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia↗
PubMed1993

Inadvertent administration of rtPA to a patient with type 1 aortic dissection and subsequent cardiac tamponade.

Administration of thrombolytic agents to patients with misdiagnosis of acute myocardial infarction can result in serious side effects. A case of aortic dissection that was misdiagnosed as acute myocardial infarction and received rtPA is reported. Within 1 hour of rtPA infusion, the patient developed cardiac tamponade. Type 1 aortic dissection was diagnosed by aortic angiogram. The patient underwent emergency resection of the dissection and evacuation of the pericardial and anterior mediastinal hematoma. Although he required massive transfusion of blood products intraoperatively, he is doing well 22 months after his surgery.

Aged↗
PubMed1993

Construction and characterization of a YAC library with a low frequency of chimeric clones from flow-sorted human chromosome 9.

Human chromosome 9 DNA, flow-sorted from somatic cell hybrid PK-87-9, has been used to construct two complete digest YAC libraries. The combined representation of chromosome 9 in these libraries, estimated by hybridization of chromosome 9-specific sequences to YAC colony grids, is approximately 95%. The frequency of chimeric clones, analyzed by fluorescence in situ hybridization of chromosome 9 YACs to human metaphase chromosomes, was estimated to be approximately 4%. These libraries provide a resource for physical mapping and for moving from genetic markers to disease loci on chromosome 9.

Chimera↗
PubMed1993

Trityl monitoring of automated DNA synthesizer operation by conductivity: a new method of real-time analysis.

AutoAnalysis is a new method for detecting and quantitating the trityl cation released each cycle on automated DNA synthesizers. The trityl (dimethoxytrityl) cation is removed from the growing oligonucleotide after each base addition and is a useful measure of synthesis efficiency. The traditional absorbance method of collecting each trityl effluent with a fraction collector, followed by dilution with an acid solution and careful quantitation by UV/VIS spectroscopy is costly, tedious and prone to error. The absorbance method for trityl cation analysis must usually wait until the synthesis is complete. Interruption of a failed operation, for a variety of reasons, such as an empty reagent reservoir, is thus not possible. Taking advantage of the conductive properties of the trityl cation, immediate and real-time quantitation is now possible by integrating the total conductance of the flowing stream during the detritylation step after each nucleoside addition in DNA synthesis. A conductivity cell is mounted downstream, past the synthesis column. The conductivity signal is processed and displayed as the current average stepwise yield and overall yield. If the yield drops below a pre-set threshold value because of a failure situation, the synthesizer will interrupt, preserving reagents. AutoAnalysis allows trityl monitoring with complete automation on the Applied Biosystems Models 392 and 394 DNA/RNA Synthesizers.

Base Sequence↗
PubMed1992

Assignment of a human DNA double-strand break repair gene (XRCC5) to chromosome 2.

The Chinese hamster ovary (CHO-K1) cell mutant XRS-6 is defective in rejoining of DNA double-strand breaks and is hypersensitive to X-rays, gamma-rays, and bleomycin. Radiation resistance or sensitivity of somatic cell hybrids constructed from the fusion of XRS-6 cells with primary human fibroblasts strongly correlated with the retention of human chromosome 2 isozyme and molecular markers. Discordancies between some chromosome 2 markers and the radiation resistance phenotype in some of the hybrid cells suggested the location of the X-ray repair cross complementing 5 (XRCC5) gene on the p arm of chromosome 2. Introduction of human chromosome 2 by microcell-mediated chromosome transfer into the radiation-sensitive XRS-6 cells resulted in hybrid cells in which the radiation sensitivity was complemented. The chromosome 2p origin of the complementing human DNA in the microcell hybrids was supported by fluorescent in situ hybridization analysis of human metaphases using human DNA amplified from the hybrids by inter-Alu-PCR as chromosome-painting probes. XRCC5 is therefore provisionally assigned to human chromosome 2p.

Animals↗
PubMed1992

The effects of patterned urge-response toileting (PURT) on urinary incontinence among nursing home residents.

OBJECTIVE: To test an individualized form of habit training for urinary incontinence (UI) among long-stay cognitively and/or physically impaired elderly nursing home residents over time. DESIGN: Randomization of subjects occurred by nursing home unit. Baseline wet checks were done hourly for one 24-hour period at 3-week intervals over 12 weeks followed by 72 hours of continuous electronic monitoring to establish precise voiding patterns for each subject. The 12-week intervention period was administered by indigenous staff after they attended a 4-hour UI educational program. Subjects were followed an additional 12 weeks to determine the extent of maintenance of the intervention among staff and subjects. SETTING: Four non-profit nursing homes; west, mid-west, east coast. PATIENTS: Consent was obtained from 154 (71%) who met primary inclusion criteria. Forty-one failed the secondary inclusion criteria leaving 113 who entered the 37-week study. Eighty-eight completed the study (experimental = 51, control = 37); all were physically and/or mentally impaired, averaged age 85, and had either urge or urge/stress UI. RESULTS: UI was significantly decreased during the 3-month period (P less than 0.001). Eighty-six percent showed improvement over baseline while one-third improved 25% or more over their baseline UI rate. The control group's UI increased during the same period of time. The volume of UI among the experimental group also decreased (P less than 0.005) while the control group's UI volume increased. CONCLUSIONS: The training program was effective in reducing UI though compliance among nursing staff averaged only 70% of the prescribed toileting times. The success of this approach is similar to other recently described behavioral programs but achieved the reduction using only regular nursing staff. This individualized approach supports the recent regulatory thrust to individualize care to promote and maintain functional abilities and autonomy.

Activities of Daily Living↗
PubMed1991

Localization in human interleukin 2 of the binding site to the alpha chain (p55) of the interleukin 2 receptor.

Human interleukin 2 (IL-2) analogs with defined amino acid substitutions were used to identify specific residues that interact with the 55-kDa subunit (p55) or alpha chain of the human IL-2 receptor. Analog proteins containing specific substitutions for Lys-35, Arg-38, Phe-42, or Lys-43 were inactive in competitive binding assays for p55. All of these analogs retained substantial competitive binding to the intermediate-affinity p70 subunit (beta chain) of the receptor complex. The analogs varied in ability to interact with the high-affinity p55/p70 receptor. Despite the lack of binding to p55, all analogs exhibited significant biological activity, as assayed on the murine CTLL cell line. The dissociation constants of Arg-38 and Phe-42 analogs for p70 were consistent with intermediate-affinity binding; the Kd values were not significantly affected by the presence of p55 in binding to the high-affinity IL-2 receptor complex. These results confirm the importance of the B alpha-helix in IL-2 as the locus for p55-receptor binding and support a revised model of IL-2-IL-2 receptor interaction.

Amino Acid Sequence↗
PubMed1991

Tissue expanders in children.

Tissue expanders are particularly applicable in the pediatric population. They are extremely well tolerated by children and can withstand the everyday play and trauma unique to children. Over the past 2 years, we have used 26 tissue expanders in 17 pediatric patients. Fifteen of the 17 patients successfully underwent reconstructive surgery with the aid of expanders. The expander became exposed in two patients, necessitating removal. In each of these patients, a more complicated and less satisfactory method of reconstruction was performed.

Adolescent↗