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Biomedical subjects

J C Sutherland

Publications and source records attributed to J C Sutherland.

At least 91 records · Page 5Linked to original sources
PubMed1978

Magnetic circular dichroism of netropsin and natural circular dichroism of the netropsin-DNA complex.

We report the first measurement of the magnetic circular dichroism (MCD) of the basic polypeptide antibiotic netropsin (Nt). The MCD shows that the longest wavelength absorption band of Nt is the sum of more than one component and permits a radically new interpretation of the circular dichroism of the complex which Nt forms with DNA. We conclude that Nt has no major effect on the CD and thus the helical structure of the bases of the DNA to which it is bound. Thus the ability of Nt to inhibit the function of DNA polymerase, RNA polymerase, and the photoreactivating enzyme must be mediated by factors other than a distortion of the helical structure of the bases.

Animals↗
PubMed1976

Photoreactivation of pyrimidine dimers in the DNA of normal and xeroderma pigmentosum cells.

Photoproducts formed in the DNA of human cells irradiated with ultraviolet light (uv) were identified as cyclobuytl pyrimidine dimers by their chromatographic mobility, reversibility to monomers upon short wavelength uv irradiation, and comparison of the kinetics of this monomerization with that of authentic cis-syn thymine-thymine dimers prepared by irradiation of thymine in ice. The level of cellular photoreactivation of these dimers reflects the level of photoreactivating enzyme measured in cell extracts. Action spectra for cellular dimer photoreactivation in the xeroderma pigmentosum line XP12BE agree in range (300 nm to at least 577 nm) and maximum (near 400 nm) with that for photoreactivation by purified human photoreactivating enzyme. Normal human cells can also photoreactivate dimers in their DNA. The action spectrum for the cellular monomerization of dimers is similar to that for photoreactivation by the photoreactivating enzyme in extracts of normal human fibroblasts.

Binding Sites↗
PubMed1976

Fungal infection of muscle in acute leukemia.

A patient with acute lymphoblastic leukemia and granulocytopenia developed fever and diffuse muscle pain and weakness while under therapy. Blood cultures grew Candida Krusei and autopsy showed diffuse muscle fungal infestation.

Adult↗
PubMed1976

A comparison of cyclophosphamide, vincristine, and prednisone (COP) with nitrogen mustard, vincristine, procarbazine, and prednisone (MOPP) in the treatment of nodular, poorly differentiated, lymphocytic lymphoma.

This study was designed to test the efficacy and toxicity of COP (cyclophosphamide, vincristine, and prednisone) and MOPP (nitrogen mustard, vincristine, prednisone, and procarbazine) in 13 previously untreated patients with disseminated, nodular, poorly differentiated, lymphocytic lymphoma, and to test for patient cross-resistance to the regimens. Complete remission was initially achieved in six of eight patients on COP and three of five on MOPP. Three patients were crossed over to the alternative induction regimen because of progressive disease after an initial partial response; one was crossed over because of toxicity. On crossover, four patients achieved complete remission, two on either regimen. Durations of unmaintained complete remission range from 6-46+ months, with 8/13 still in their first complete remission. Only one patient has died, while in remission, from progressive Kaposi's sarcoma; one was lost to follow-up while in complete remission at 44 months; the others (85%) remain alive 33-54 months from the initiation of chemotherapy. MOPP was significantly more toxic with respect to thrombocytopenia, duration of myelosuppression, and cumulation of toxicity. Because of its more acceptable toxicity, COP is recommended as initial therapy for patients with nodular, poorly differentiated, lymphocytic lymphoma. MOPP or another regimen of non-crossresistant combination chemotherapy would be more appropriate for primary treatment failures.

Adult↗
PubMed1976

Clinically significant cardiac infiltration in acute leukemia, lymphocytic lymphoma, and plasma cell myeloma.

Cardiac infiltration by hematologic neoplasms leading to clinically significant cardiovascular disease is rare. Three such cases are described in this report, and it is suggested that rare manifestations of hematologic neoplasms may become more common in the future since these diseases are more amenable to therapy than heretofore. Cardiac involvement with hematologic neoplasms is of more than academic interest since this complication is likely to respond to radiotherapy.

Adult↗
PubMed1976

Torulopsis glabrata infections in patients with cancer. Increasing incidence and relationship to colonization.

Torulopsis glabrata, an opportunistic pathogen, was found to be the etiologic agent of infections in patients with cancer. This observation prompted a retrospective review to determine the incidence and underlying factors of infection with this organism. This study showed that T. glabrata had been cultured frequently and that the incidence of infection has been progressively increasing. During a 48-month period (9/70-8/74), T. glabrata was cultured from routine surveillance and diagnostic cultures in 167 patients, 27 of whom had either presumed or documented infection. Review of clinical and necropsy records implicated T. glabrata infections as a contributory factor in the death of 14 of the 27 patients. Etiologic diagnosis of infection was established antemortem in only three patients. Pulmonary isolation in pure growth occurred in 24 of the 27 patients. Seventeen of 19 infected patients who had prior routine surveillance cultures were colonized prior to infection. Infection occurred in the setting of far advanced malignancy or leukopenia and followed the use of systemic, broad spectrum antibiotics. T. glabrata is a frequently overlooked opportunistic pathogen which, in the proper setting, appears to be producing increasing numbers of infections.

Bone Neoplasms↗
PubMed1976

Fluorescence-detected magnetic circular dichroism of fluorescent and nonfluorescent molecules.

We have modified a spectrometer for the measurement of fluorescence-detected magnetic (and natural) circular dichroism (FDMCD). The instrument can be operated either in a direct mode in which the average and polarization-induced differential fluorescent intensities are recorded separately or in a mode which records their ratio. We have measured the FDMCD of tryptophan, which is itself fluorescent. With the aid of an added fluorescent molecule we also measured the FDMCD of Fe(III) cytochrome c, which is nonfluorescent. In both cases, the FDMCD agreed with the conventional transmission-detected magnetic circular dichroism within experimental uncertainty. The FDMCD of both fluorescent and nonfluorescent molecules is potentially a useful technique for investigating optically dense materials and biological molecules in their native environments and systems in which there is inter- or intramolecular energy transfer.

Circular Dichroism↗
PubMed1976

High dose imtermittent intravenous cyclophosphamide in non-Hodgkin's lymphomas: long-term patient follow-up.

This report summarizes the clinical course of 17 patients with non-Hodgkin's lymphomas who were treated with high dose intermittent intravenous cyclophosphamide between 1966 and 1968. Diagnostic biopsies have been reclassified according to the Rappaport classification. Five patients were found to have diffuse lymphomas, none of whom experienced complete remission or prolonged survival. Twelve patients had nodular lymphomas, five of whom achieved complete remission lasting from 22 to 113+ months (mean 59+ months). Two patients survived 78 and 113+ months, respectively, with no sign of recurrence. High dose cyclophosphamide alone may provide long term control of some patients with nodular lymphomas.

Adult↗
PubMed1975

Role of 67gallium citrate scanning in the management of non-Hodgkin's lymphoma.

67Gallium scans were performed as part of the initial evaluation in 45 patients with non-Hodgkin's lymphoma. Eighteen of these patients underwent staging laparotomy and splenectomy. In addition, scans were performed either shortly after therapy was completed or during subsequent followup in 10 patients. The initial scans were found most useful for patients with histiocytic lymphoma: in detecting sites of involvement above the diaphragm and the high para-aortic/mesenteric region, and when tumors were greater than 2 cm in diameter. The addition of 67Ga scanning to the pre-operative clinical evaluation reduced the number of incorrectly staged patients from 8 to 4. Reversion of previously positive 67Ga scans to negative in 3 patients with suspected persistent or recurrent disease was associated with fibrosis and no lymphoma when biopsied. Five other patients had histologically documented positive 67Ga scans post-therapy; in 1 the 67Ga scan was only definitive noninvasive procedure. Despite the occurrence of both false-positive and false-negative 67Ga scans, this procedure appears to be a useful supplement to the pretreatment evaluation of patients with non-Hodgkin's lymphoma, especially the histiocytic form. Confirmation of its ability to detect high para-aortic/mesentric involvement may subsequently result in a reduction of the number of staging laparotomies necessary. For the post-treatment followup of these patients 67Ga scans may prove to be valuable noninvasive investigation.

Abdominal Neoplasms↗
PubMed1975

Radiation-related pericardial effusions in patients with Hodgkin's disease.

Pericardial effusions following radiotherapy for Hodgkins Disease have previously been described as infrequent and related to the total dose of radiation received. Analysis of all chest x-rays on 81 patients who received upper-mantle radiotherapy for Hodgkins Disease at the Baltimore Cancer Research Center between 1968 and 1972 disclosed an incidence of pericardial effusions of 30.9% (25 of 81), with 13.6% (11 of 81) requiring limitation of activity (5) or pericardiectomy (6). Clinical presentation of radiation-related percardial effusions was subtle, with signs and symptoms a late finding if they occurred. Radiotherapy data was reviewed and no difference in total dose (rads) or time-dose relationships (rets) was found between the groups who did or did not develop effusions. Analysis of multiple pre-treatment clinical and pathological characteristics disclosed four parameters that were felt to be related to the development of pericardial effusions; elevated ESR, normal absolute lymphocyte count, initial presence of extensive mediastinal adenopathy and the addition of adjuvant chemotherapy. The presence of increasing combinations of these pretreatment 'risk factors' led to an increasing likelihood of developing a radiation-related pericardial effusion such that six of seven patients with all four 'risk factors' developed a pericardial effusion. Nine of 13 clinically significant effusions were associated with the addition of adjuvant chemotherapy. Possible pathogenetic mechanisms that include factors other than radiation dosage and the clinical management of radiation-related pericardial effusions are discussed.

Adult↗
PubMed1975

Continuous spectrophotometric measurements of arteriovenous oxygen difference.

A relatively inexpensive dual-beam optical absorbance monitor was tested and adapted to measure arterio-enous oxygen difference ((a - v)delta O2). Since the molar extinction coefficients of oxy- and deoxyhemoglobin are markedly different at 660 nm, the difference in optical density between arterial and venous blood, as measured by the absorbance monitor, was shown to be linearly related to (a - v)delta02. When appropriate cuvettes (optical path length = 0.5 mm) were used, the instrument's 90% response time (4.4 s) was sufficiently rapid for most physiological applications such as Fick determinations of the rate of an organ's oxygen consumption. The theoretical basis of this spectrophotometric (a - v)deltaO2 measurement and sources of error are discussed in detail.

Animals↗