Biomedical subjects

B A Murphy

Publications and source records attributed to B A Murphy.

34 records · Page 2Linked to original sources

PubMed1998

Evidence for normal aging of the septo-hippocampal cholinergic system in apoE (-/-) mice but impaired clearance of axonal degeneration products following injury.

The association of the epsilon4 allele of apoE with increased risk for Alzheimer's disease (AD) and with poor clinical outcome after certain acute brain injuries has sparked interest in the neurobiology of apoE. ApoE (-/-) mice provide a tool to investigate the role of apoE in the nervous system in vivo. Since integrity of the basal forebrain cholinergic system is severely compromised in AD, with severity of dysfunction correlating with apoE4 gene dosage, the present study tested the hypothesis that apoE is required to maintain the normal integrity of basal forebrain cholinergic neurons (BFCNs). Histological and biochemical analyses of the septo-hippocampal cholinergic system were performed in apoE (-/-) mice during aging and following injury. Using unbiased quantitative methods, there was little or no evidence for defects in the septo-hippocampal cholinergic system, as assessed by p75(NTR)-immunoreactive neuron number and size in the medial septum, cholinergic fiber density in the hippocampus, and choline acetyltransferase activity in the hippocampus, cortex, and striatum in aged apoE (-/-) mice (up to 24 months of age) as compared to age-matched wild-type mice of the same strain. In addition, cholinergic neuronal survival and size following fimbria-fornix transection in apoE (-/-) mice did not differ from controls. However, following entorhinal cortex lesion, there was persistence of degeneration products in the deafferented hippocampus in apoE (-/-) mice. These data suggest that although apoE is not required for the maintenance of BFCNs in vivo, it may play a role in the clearance of cholesterol-laden neurodegeneration products following brain injury.

Aging↗

PubMed1998

Production of leptin in Escherichia coli: a comparison of methods.

A procedure is described for gram-scale refolding of Escherichia coli-derived human leptin inclusion bodies. Refolding was achieved by gradually reducing denaturant using a diafiltration method. Refolded leptin is characterized by in vivo modulation of food intake, reduction in body weight, and lowering of insulin and glucose levels in ob/ob mice. In addition, refolded leptin is characterized by radioimmunoassay (RIA) and activation of the leptin receptor in a cell-based assay. For comparison we also refolded leptin by a simple dilution method and produced periplasmic derived leptin, which did not require ex vivo folding. Leptin produced by these three methods and leptin obtained from commercial sources were compared using the RIA and the cell-based assay and appeared to be of comparable quality and potency.

Animals↗

PubMed1997

Acquired capillary hemangioma of the eyelid in an adult.

PURPOSE: To report a case of an acquired capillary hemangioma of the eyelid in an adult. METHODS: A 38-year-old man developed a discrete blue nodular mass in the lower eyelid. The lesion grew slowly for 6 months and then remained stable in size. Excisional biopsy was performed. RESULTS: Histopathologic examination of an excisional biopsy specimen of the nodular mass disclosed a capillary hemangioma. CONCLUSIONS: Capillary hemangioma of the eyelid can occur in adults but should be distinguished from other acquired vascular lesions, including angiosarcoma.

Adult↗

PubMed1997

Cloricromene reduces myocardial infarct size in rabbits when administered during the early reperfusion period.

Cloricromene is a coumarin derivative without anticoagulant activities that has recently been found to decrease myocardial infarct size after an ischemic-reperfusion injury. This study seeks to determine when the cardioprotective action of cloricromene is exerted in an in vivo rabbit model of ischemic-reperfusion injury. Forty-nine rabbits subjected to 30 min of coronary occlusion and 120 min of reperfusion were randomized into five groups: VEH (n = 11) received saline vehicle; IR (n = 9) received an infusion of cloricromene starting at the onset of ischemia at 8 micrograms.kg-1.min-1; R(-5)(n = 9) and R(+30)(n = 9) received an infusion of cloricromene at 8 micrograms.kg-1.min-1 starting 5 min before reperfusion and 30 min after reperfusion, respectively; and RB(-5)(n = 11) received 300 micrograms/kg bolus of cloricromene 5 min before reperfusion followed by an infusion of 8 micrograms.kg-1.min-1. All infusions were continued until the end of the reperfusion period. Myocardial infarct size was significantly reduced in groups IR, R(-5), and RB(-5). We conclude that cloricromene's effective time of action occurs prior to the first 30 min of the reperfusion period.

Animals↗

PubMed1997

The effect of esmolol on ST-segment depression and arrhythmias after electroconvulsive therapy.

Electroconvulsive therapy (ECT) induces sympathetically mediated hemodynamic alterations that can be associated with myocardial ischemia and arrhythmia generation. Esmolol, a short-acting beta-blocker, blunts the hypertension and tachycardia seen with ECT. The purpose of this study is to determine whether esmolol use during ECT reduces the incidence of myocardial ischemia or arrhythmias after ECT. In a randomized, double-blind, placebo-controlled protocol, with each patient acting as his/her own control, the effects of esmolol on the incidence of myocardial ischemia and arrhythmias were studied using two-lead Holter monitoring for at least 2 h post-ECT. Nineteen patients underwent 71 ECT treatments (34 placebo, 37 esmolol), recording 746 h of Holter data. The esmolol group had significantly reduced heart rate and mean arterial pressure immediately after ECT. There was no difference in the incidence of ECG defined ischemia post-ECT between groups, with 7 of 19 (36.8%) patients in the esmolol group showing ST-segment depression compared with 5 of 19 (26.3%) in the placebo group. There was no difference between groups in arrhythmia detection. This experiment demonstrates that (a) ECT is associated with a significant incidence of ST-segment depression, (b) esmolol blunts the sympathetic discharge during ECT, and (c) esmolol does not reduce the incidence of post-ECT ischemia or arrhythmia.

Adrenergic beta-Antagonists↗

PubMed1996

New drug therapy for squamous carcinoma of the head and neck.

The identification of new active agents for the treatment of squamous carcinoma of the head and neck remains a high priority for clinical investigators. For the past several years a number of investigational drugs have demonstrated activity in patients with recurrent or metastatic disease. Included are the following agents: gemcitabine, vinorelbine, paclitaxel, docetaxel, and ifosfamide. Further studies are underway to investigate the role of these agents in combination regimens. Randomized phase III trials comparing promising new regimens to standard therapy with methotrexate or cisplatin and 5-fluorouracil will be necessary.

Antimetabolites, Antineoplastic↗

PubMed1996

Extra-acral calcifying aponeurotic fibroma: a distinctive case with 23-year follow-up.

Calcifying aponeurotic fibroma (CAF) is an unusual but well-characterized soft tissue neoplasm that typically involves the digits of children and frequently recurs locally. This report describes a case from the subcutis of the lumbosacral region. A 26-year-old man initially presented at age 3 and developed three recurrences over a 23-year period each at approximately 8-year intervals (ages 10, 18, and 26). The microscopic findings in all recurrences showed a lobulated, poorly circumscribed proliferation of dense fibrous tissue containing epithelioid-like fibroblasts, multinucleated cells, and islands of metaplastic chondroid differentiation with focal calcification. Despite origin from an unusual anatomic site, this case reported herein demonstrates the classical morphologic features and clinical history of CAF which showed little in the way of morphologic evolution despite 23 years of persistence. The clinical and histologic features helpful in distinguishing CAF from infantile fibromatosis and soft tissue chondroma are discussed.

Adult↗

PubMed1996

Communication survey of CH-47D crewmembers.

U.S. Army CH-47D cargo helicopter crewmembers are exposed to high levels of noise on a routine basis, yet must accomplish demanding missions that rely heavily on clear communication. This study looked at the auditory influences affecting communication by 17 crewmembers of a CH-47D Army Reserve unit. Results revealed (1) noise levels that exceed those of other Army rotary-winged aircraft, (2) different exposure levels for aviators and crewchiefs, (3) an overall preference for hearing "critical or diagnostic" aircraft sounds rather than wearing double hearing protection, (4) complaints of post-flight tinnitus or muffled hearing, (5) helmet discomfort among the majority of crewmembers, (6) a high incidence of hearing loss, (7) difficulties in adjusting radio volume controls for aviators, and (8) the effects of eyeglasses or protective masks on hearing and communications.

Adult↗

PubMed1995

all-trans retinoic acid for treating germ cell tumors. In vitro activity and results of a phase II trial.

BACKGROUND: Germ cell tumors (GCTs) are characterized by a capacity to differentiate in vivo and in vitro. The authors' previous work highlighted the finding that retinoid-mediated GCT differentiation in vitro correlates with expression of the retinoic acid receptor-gamma. METHODS: Six human GCT cell lines were studied to determine whether their growth and differentiation were linked to the retinoic acid response pathway. The maturation and growth inhibitory responses to all-trans retinoic acid (RA) were studied as well as the expression of retinoic acid receptor-gamma (RAR-gamma). The clinical antitumor activity of RA was studied in a Phase II trial of RA in patients with chemotherapy-refractory GCTs. RESULTS: The RA response pathway was correlated with the control of growth and maturation in three of the six GCT cell lines studied. In one GCT cell line, RA induced RAR-gamma expression and terminal differentiation. In a second, there was high basal expression of RAR-gamma and poor basal proliferative potential. A third cell line showed a more mature basal phenotype than other cell lines studied and marked growth inhibition when treated with RA. Sixteen patients were treated with RA for an average of 7 weeks in the clinical trial. No complete or partial responses were noted. CONCLUSION: A Phase II clinical trial of RA failed to show significant clinical antitumor activity in patients with chemotherapy-refractory GCTs. However in vitro data suggest that the control of growth and maturation in some GCT cell lines involve the RA signaling pathway. Further studies are warranted to define the role that other retinoids with receptor selectivity or more favorable pharmacologic properties may play in the maturation or antitumor responses of GCTs.

Adolescent↗

PubMed1995

Interferon alfa-2a and 13-cis-retinoic acid in renal cell carcinoma: antitumor activity in a phase II trial and interactions in vitro.

PURPOSE: A phase II trial of interferon alfa-2a (IFN) and 13-cis-retinoic acid (CRA) was conducted in patients with renal cell carcinoma (RCC). In vitro studies were performed to investigate potential mechanisms of interaction. PATIENTS AND METHODS: Forty-four patients were treated. IFN was given daily at 3 MU and escalated to 6 and 9 MU if tolerated. The dose of CRA was 1 mg/kg/d. The effects of combining CRA and IFN on the proliferation of five RCC cell lines were examined, and retinoid sensitivity was correlated to the expression of retinoic acid receptors. RESULTS: Thirteen (30%) of 43 assessable patients achieved a major response (three complete and 10 partial). Responding sites included bone metastases and renal primary tumors. Seven responding patients remain progression-free at 10+ to 19+ months. The response proportion was higher than in our prior experience with IFN, which was 10% in 149 patients. Eleven of 12 renal cancer cell lines were resistant to CRA alone; one, SK-RC-06, showed 90% inhibition of cell growth. CRA augmented the antiproliferative effect of IFN in several IFN-sensitive cell lines, but not in IFN-resistant lines. Northern blot analysis showed that expression of retinoic acid receptor-beta (RAR-beta) was repressed and not induced by retinoic acid in retinoic acid-insensitive RCC lines. However, RAR-beta expression was induced by retinoic acid in SK-RC-06 cells. CONCLUSION: IFN and CRA showed antitumor activity in patients with advanced RCC, and the proportion and nature of response suggested CRA added therapeutic benefit to IFN. A phase III randomized trial of IFN plus CRA versus IFN alone and a phase II trial of single-agent CRA have been initiated.

Adolescent↗

PubMed1995

Sacroiliac joint manipulation decreases the H-reflex.

Joint manipulation is widely utilized clinically to decrease pain and increase the range of motion of joints displaying limited mobility. Evidence of efficacy is based on subjective reports of symptom improvement as well as on the results of clinical trials. Experiments were designed to determine whether or not sacroiliac joint manipulation affects the amplitude of the Hoffman (H) reflex. Surface EMG recordings of the reflex response to electrical stimulation of the tibial nerve in the popliteal fossa were made from the soleus muscle. The averaged amplitudes of H-reflexes were compared on both legs before and after either sacroiliac joint manipulation or a sham procedure. H-reflex amplitude was significantly decreased (12.9%) in the ipsilateral leg (p < 0.001) following a sacroiliac joint manipulation while there was no significant alteration following the sham intervention. There was no significant alteration in reflex excitability in the contralateral leg to the sacroiliac joint manipulation. To further investigate the mechanism of these reflex alterations, the local anaesthetic cream EMLA (Astra Pharmaceuticals) was applied to the skin overlying the sacroiliac joint and the experiments were repeated on a different group of subjects. This was intended to determine if excitation of cutaneous afferents was responsible for the reflex excitability changes. There was still a significant decrease in reflex excitability (10.6%) following sacroiliac joint manipulation (p < 0.001). These findings indicate that joint manipulation exerts physiological effects on the central nervous system, probably at the segmental level. The fact that the changes persisted in the presence of cutaneous anaesthesia suggests that the reflex changes are likely to be mediated by joint and/or muscle afferents.

Adolescent↗

PubMed1994

Serum tumor marker decline is an early predictor of treatment outcome in germ cell tumor patients treated with cisplatin and ifosfamide salvage chemotherapy.

BACKGROUND: Serum tumor marker regression (alpha-fetoprotein [AFP] and human chorionic gonadotrophin [hCG]) was studied in patients treated with ifosfamide-based chemotherapy for cisplatin-resistant germ cell tumors (GCT) to investigate the role of marker regression as a predictor of treatment outcome. METHODS: Fifty-four patients treated with cisplatin and ifosfamide-containing therapy were the subject of this retrospective analysis. The serum tumor marker half-life (T1/2) for the first two cycles of therapy was calculated for each patient using all marker values Day 7 through the end of the second treatment cycle. A calculated T1/2 for hCG of less than or equal to 3 days or a calculated T1/2 for AFP of less than or equal to 7 days was defined as appropriate marker regression; any T1/2 greater than these values was considered prolonged. A variable designated "marker decline" was defined to indicate whether the serum tumor marker half-life of AFP and/or hCG was satisfactory or unsatisfactory for each individual patient. Both univariate and multivariate analyses were conducted to investigate "marker decline" as a predictor for response, event-free survival (time to death or relapse), and overall survival. RESULTS: Satisfactory marker decline predicted an improved event-free survival and overall survival. The median event-free survival for patients with an unsatisfactory marker decline was 5.8 months versus 20.7 months for patients with a satisfactory marker decline. Survival for patients with an unsatisfactory marker decline was 6.3 months versus 20.7 months for those patients with a satisfactory marker decline. Further evaluation demonstrated that hCG decline was a stronger predictor for improved survival than AFP decline. A multivariate analysis performed on selected clinical variables using a Cox regression model demonstrated that marker decline, pretreatment hCG, and primary site were independent predictors for event-free and overall survival. CONCLUSIONS: The rate of serum AFP and/or hCG decline during the first two cycles of therapy was predictive for event-free and overall survival in GCT patients treated with ifosfamide-based salvage therapy. Those patients with an appropriate serum tumor marker decline had a longer event-free and overall survival. When evaluated separately, the rate of hCG decline was more predictive of treatment outcome than decline of AFP. The rate of serum tumor marker regression during the first two cycles of therapy is a clinically useful tool in assessing treatment outcome at an early point in therapy and may thereby identify patients who could benefit from a change to more intensive therapy.

Biomarkers, Tumor↗

PubMed1993

Mosaic 5p tetrasomy.

We report on a mildly abnormal 5-year-old girl with seizures, psychomotor retardation, and areas of hyperpigmentation who had a supernumerary marker chromosome in fibroblasts which was identified as an i(5p). To our knowledge, this is the first reported case of tetrasomy 5p. She shares in common some, but not all, manifestations of the dup (5p) syndrome. Cytogenetic analysis of relatives showed that the phenotypically apparently normal mother, maternal grandmother, and a brother of the proband also had a marker chromosome in their lymphocytes which was unrelated to the i(5p).

Abnormalities, Multiple↗

PubMed1992

Phase II study of iproplatin (CHIP) in patients with cisplatin-refractory germ cell tumors; the need for alternative strategies in the investigation of new agents in GCT.

Fifteen patients with advanced, cisplatin-refractory germ cell tumors (GCT) were treated with iproplatin (CHIP). No objective responses were noted in any of the patients treated. By restricting the entry criteria to heavily pre-treated patients, the identification of new active agents in phase II trials may be hindered. Alternative strategies for the investigation of new agents in patients with GCT should be considered, particularly when studying the efficacy and relative toxicity of platinum analogues.

Antineoplastic Agents↗

PubMed1992

Longitudinal cytogenetic study of metaphase and interphase cells in childhood monosomy 7 syndrome.

A 15-year-old male with myelodysplastic syndrome (MDS) characterized by monosomy 7 was cytogenetically evaluated by metaphase karyotyping and fluorescence in situ hybridization (FISH) of interphase cells at six different points during the course of his disease. At diagnosis, there was complete agreement between metaphase and interphase findings. Interphase analysis alone provided important cytogenetic information on the first specimens received following intensive combination chemotherapy and bone marrow transplantation where metaphase analyses were uninformative. The detection of a minor post-treatment monosomy 7 population by interphase but not metaphase studies may have identified minimal residual disease prior to recurrence of MDS. From this longitudinal study, it is concluded that metaphase and interphase cytogenetic analyses form complementary approaches and that use of both provides greater analytical power when appropriate chromosome markers are available.

Adolescent↗

PubMedDate not supplied

The assessment of intramuscular discrimination using signal detection theory: its potential contribution to chiropractic.

INTRODUCTION: Most studies on sensory changes after manual therapies have focused on pain sensitivity. This ignores the wider range of sensory alternations that may be important in assessing patient functioning and neglects the issue of bias, which is inherent in most methods of pain assessment employing threshold methodology. Signal detection theory (SDT) addresses the issue of bias and provides a measurement of intramuscular discrimination--the ability to discriminate between two stimuli--which can be assessed over the full range of sensation. This paper will discuss the strengths and limitations of SDT and report on the effects of trigger point therapy and manipulation on intramuscular discrimination to illustrate the potential contribution of this methodology to chiropractic. METHODS: Intramuscular needle electrodes were used to provide a pair of electrical stimuli to the forearm extensor muscles. Subjects were asked to assess the differences between stimuli before and after treatment. The treatments consisted of manual trigger point therapy applied to the forearm extensors, cervical spine manipulation and a control treatment. RESULTS: After the trigger point therapy, there was a significant improvement in the ability of the subjects to discriminate between intramuscular signals to treated muscle. Some individual subjects showed alterations in ability to discriminate after cervical spine manipulation but the effect was not significant in the group as a whole. CONCLUSIONS: The methodology of signal detection theory provides a promising, bias-free method of assessing changes in intramuscular sensation after various treatments. In these experiments, trigger point therapy was found to enhance intramuscular discrimination, suggesting that a peripheral reflex may be involved.

Adolescent↗