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Biomedical subjects

P Murphy

Publications and source records attributed to P Murphy.

At least 271 records · Page 15Linked to original sources
PubMed1978

Endotracheal irradiation of adenoid cystic carcinoma of the trachea.

Management of advanced or recurrent primary tracheal neoplasms has been restricted to palliative external beam irradiation. A patient with recurrent adenoid cystic carcinoma of the trachea was recently treated again by combined external irradiation and endotracheal brachytherapy with iridium 192 sources; the results were dramatic without significant normal tissue toxicity. This endotracheal brachytherapy technique might be applied to tracheal tumors of different histology or more limited extent.

Adult↗
PubMed1977

Clinical significance of scintillation camera electronics capable of high processing rates.

The use of larger scintillation detectors with high-efficiency converging collimators has greatly increased the photon input rate to the crystals of scintillation cameras in many clinical studies. To process these high-count-rate data accurately, modifications have been made by some manufacturers in the electronics of scintillation cameras. Cameras with new electronic design were compared with earlier models with respect to count rate processing capability and the effect of high input rate on spatial resolution, pulse-pair pileup, image size, and instability of the amplification of energy pulses. The improvements with the new electronic design result in shorter imaging times, better preservation of resolution, increased statistical reliability, and reduced distortion of dynamic tracer curves used for quantitative analysis.

Coronary Circulation↗
PubMed1976

Pharmacokinetic studies in the chemotherapy of neuroblastoma using the C1300 murine system.

The transplantable C1300 murine neuroblastoma has been characterized biochemically and an in vivo model for the screening of new therapeutic approaches to the treatment of neuroblastoma developed. Subcutaneous inoculation of A/J mice with 10)6) C1300 cells results in predictable tumor growth and animal death in 25 +/- 4 days. Tumor growth is Gompertzian, correlates with increases in tumor RNA and DNA content and with the rate of tumor DNA synthesis as measured by [3H] thymidine incorporation. The model proposed is based on the degree to which various therapeutic options are able to inhibit tumor DNA synthesis, and these observations have been confirmed autoradiographically. A single course of either cyclophosphamide (25, 50, 100 or 200 mg/kg), BCNU (2, 7.5, 15, or 30 mg/kg) or cytosine arabinoside (15, 30, 60, 90 mg/kg) resulted in dose-related inhibition of tumor DNA synthesis. The maximum decline in DNA synthesis that was produced by the highest dose of each agent was by 81%, 77% and 68% of untreated tumor values respectively. Adriamycin, however, even at lethal levels (10 mg/kg), did not elicit significant inhibition of tumor DNA synthesis. Radiotherapy (200 R, 500 R or 1000 R) also produced graded inhibition of tumor DNA synthesis. This model is potentially useful for the preclinical screening of therapuetic options in the treatment of neuroblastoma. Thus, single agent therapy, combination chemotherapy and combined radiotherapy and chemotherapy may be rapidly evaluated for possible clinical use.

Animals↗
PubMed1975

Structure of coat proteins in Pf1 and fd virions by laser raman spectroscopy.

Rama spectra of filamentous bacterial viruses are dominated by scattering from vibrations of the protein capsomers. The amino acid compositions of coat proteins in Pfl and fd strains are recognized by their different side-chain vibrational frequencies. However, the conformationally sensitive amide frequencies indicate that Pfl and fd coat proteins have the same alpha-helicial secondary structures. Viral DNA backbones do not exhibit the A-type geometry.

Animals↗
PubMed1975

Effects of anesthesia, surgery and inflammation upon host defense mechanisms. I. Effects upon the complement system.

Complement protein levels and C7 hemolytic activity were measured in four individuals following anesthesia and surgery, and in a group of 20 patients with inflammatory diseases. Seven of the eight complement components studied characteristically were elevated, most dramatically C1s and C3PA. Elevation of C1s often was greater than elevation of C1q, displaying an independent variation of C1s and C1q in both postoperative and inflammatory disease patient groupds. The major increases of C components were seen subsequent to the peak C-reactive protein response, as was the occurrence of the 'reactor state', a propensity to formation of C56 which surprisingly was associated with increased levels of C7. Levels of properdin frequently were reduced postoperatively. It is concluded that multiple complement components, with the notable exception of properdin, respond as acute phase reactants which are elevated and changed in proportion postoperatively and during inflammatory disease.

Anesthesia, General↗