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Biomedical subjects

S Donaldson

Publications and source records attributed to S Donaldson.

17 recordsLinked to original sources
PubMed1997

Bronchoalveolar lavage: comparison of nucleopore filters and direct smear preparations.

To determine whether cytopreparation affects the diagnostic yield of bronchoalveolar lavage specimens, we compared 50 lavage samples by using two methods. One nucleopore filter preparation and four direct slides were prepared on each sample submitted. All slides were stained by the Papanicolaou method. Assessment of cellularity, cellular preservation, and an independent diagnosis were rendered on each sample for both preparatory methods. Statistical analysis showed no difference in cellularity between the two methods (P = .06). The degree of nuclear and cytoplasmic preservation was higher using the direct method, although this did not appear to affect diagnosis in this study. One major discrepancy in diagnosis was observed between the two methods. By prospectively comparing nucleopore filter and direct preparation of bronchoalveolar lavages, we found that there was minimal affect on either cellularity or diagnosis. We conclude that either method delivers reliable cytologic results.

Bronchoalveolar Lavage↗
PubMed1997

Involvement of central cholinergic system in antinociception induced by sumatriptan in mouse.

The antinociceptive effect of the antimigraine drug sumatriptan was assessed in mice (hot-plate and abdominal constriction tests). Antinociception induced by sumatriptan (10-30 mg kg-1 i.p.) was prevented by the muscarinic antagonist atropine (5 mg kg-1 i.p.), the ACh-depletor hemicolinium-3 (1 microgram per mouse i.c.v.) and the 5-HT1A antagonist NAN-190 (0.5 mg kg-1 i.p.). Naloxone, CGP-35348 and reserpine administered in doses suitable for blocking analgesia respectively induced by morphine, baclofen and clomipramine did not modify sumatriptan antinociception. On the basis of the above findings, we can deduce that sumatriptan was able to induce antinociception by increasing cholinergic neurotransmission through the stimulation of 5-HT1A receptors.

Analgesics↗
PubMed1996

Skin testing with Mycobacterium avium sensitin to identify infection with M. avium complex in patients with cystic fibrosis.

We sought to determine if patients with cystic fibrosis and sputum cultures positive for Mycobacterium avium complex (MAC) have delayed-type hypersensitivity to an M. avium sensitin. Seventeen (33%) of 51 selected patients had MAC isolated from at least one sputum culture. Skin tests with purified protein derivative and M. avium sensitin demonstrated that five (10%) of 51 patients were anergic, and anergy was correlated with use of systemic steroids. Sixteen (35%) of 46 nonanergic patients had M. avium-dominant skin test reactions. Twelve (75%) of these 16 patients with cultures positive for MAC had M. avium-dominant skin tests; the specificity of skin testing was 87%. These data suggest that most patients with cystic fibrosis and sputum cultures positive for MAC have infection rather than colonization with MAC. Skin testing with M. avium sensitin is a sensitive and specific method for screening these infections.

Adolescent↗
PubMed1996

Acute and chronic lung allograft rejection during pregnancy.

Young women who undergo lung transplantation may regain normal fertility and become pregnant. Currently, little is known about the outcome of pregnancy after lung transplantation. We present a case of pregnancy after bilateral lung transplantation complicated by acute and chronic allograft rejection, resulting in irreversible loss of lung function.

Abortion, Therapeutic↗
PubMed1994

Retroperitoneal node biopsy in paratesticular rhabdomyosarcoma.

UNLABELLED: Retroperitoneal lymph node dissection (RPLND) was used in 121 Intergroup Rhabdomyosarcoma Study (IRS) III patients with nonmetastatic paratesticular (PT) rhabdomyosarcoma (RMS) to assess retroperitoneal lymph node (RPLN) involvement so as to determine the need for x-ray therapy (XRT). Clinical node evaluation (CNE) was accomplished by a computed tomography (CT) scan in 105 and a sonogram in six. Pathological node evaluation (PNE) was performed in 113: lymphadenectomy (9 bilateral, 85 unilateral) and biopsy in 19. Vincristine and actinomycin D were used for 1 year postoperatively in 89%; all patients who had positive PNE received RPLN XRT. This study compares CNE with PNE and evaluates predictors of relapse and survival. FINDINGS: There were clinically negative nodes (cN0) in 81% of the 121 patients. Among cN0 patients, 14% had positive nodes (pN1). Of the clinically positive (cN1) patients, 94% had pN1. RPLN relapse occurred in only two of the 121 patients. Initially both had cN0 and one had PNE that was negative. For all 121 patients, the 5-year survival was 91%. For cN0 patients, the 5-year survival was 96% compared with 69% for cN1 patients (P < .001). Among the children in whom treatment failed, nodes were cN1 in 5 of 11 (45%) compared with 15 of 107 (14%) in those whose treatment did not fail (P < .008). CONCLUSIONS: (1) Results of RPLN imaging studies were negative in 81% of patients with PT RMS (specificity 99%, sensitivity 57%). (2) RPLN recurrence is uncommon (even when RPLN are initially involved) if regional XRT and appropriate chemotherapy are used.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Prognostic features of Ewing sarcoma on plain radiograph and computed tomography scan after initial treatment. A Pediatric Oncology Group study (8346)

BACKGROUND: The authors studied the short-term changes in the plain radiographic and computed tomography (CT) appearance of Ewing sarcoma for indicators of decreased survival or future disease progression. METHODS: The authors evaluated CT scans and plain radiographs of the primary tumor site from 105 patients with Ewing sarcoma at diagnosis (prebiopsy), after induction chemotherapy (13 weeks), and after radiation therapy (20 weeks). RESULTS: Data suggest an association between postinduction CT findings of medullary involvement, cortical destruction, lysis, permeation, and unhealed pathologic fracture and decreased survival. On the postradiation scans, only medullary involvement was associated with worsened survival. No plain radiographic features were significant at any time. Absolute greatest tumor dimension was not significantly related to survival or tumor progression. The Cox model suggested that fractional change in greatest tumor dimension on CT at the time points studied relative to the prebiopsy CT was correlated to survival. Log-rank testing did not corroborate this finding. All significant associations appeared to result from adverse outcomes in small subgroups. CONCLUSIONS: Our data suggest that CT obtained immediately after induction chemotherapy and radiation may have some limited use in predicting the long-term prognosis of patients with Ewing sarcoma.

Actuarial Analysis↗
PubMed1990

Nasopharyngeal carcinoma in the young: a combined M.D. Anderson and Stanford experience.

From 1956 to 1988, 57 children and young adults (age 4-21 years) with a diagnosis of nasopharyngeal carcinoma were treated at The University of Texas M.D. Anderson Cancer Center (42 patients) and Stanford University Medical Center (15 patients). The male to female ratio was 2:1. Forty-three patients had lymphoepithelioma, seven had undifferentiated neoplasms, and seven had squamous cell carcinoma. Two patients had Stage III disease and the remainder had Stage IV disease at the time of presentation. All patients were treated with primary radiotherapy, and 14 patients also had chemotherapy with combinations of the following drugs: dactinomycin, doxorubicin, bleomycin, cisplatin, cyclophosphamide, fluorouracil, methotrexate, and vincristine. Twenty-six patients are alive 6 to 178 months from the first day of treatment (median 93 months). The 5- and 10-year actuarial survival rates are 51% and 36%, respectively, and the corresponding disease specific survival rates were 51% and 51%. There were no recurrences after 42 months. The patterns of failure were as follows: distant metastasis only, 21 patients; locoregional metastasis only, 1; both, 5. Distant metastases most commonly occurred in bones, lungs, liver, and mediastinal lymph nodes. Chronic treatment-related morbidity was encountered in a significant number of long term survivors. Trends in the data not reaching statistical significance suggest a more favorable prognosis for a) females, b) patients less than or equal to 15 years of age, c) lymphoepithelioma or undifferentiated histologies, d) stages T3-4 NO-1 vs T1-2 N2-3 vs T3-4 N2-3, e) primary tumor dose greater than or equal to 65 Gy and f) patients who received chemotherapy.

Adolescent↗
PubMed1986

Neuro-ocular damage in pediatric oncology patients: predictor of long-term visual disability or tool for limiting toxicity?

We present a group of eight pediatric cancer patients with a spectrum of visual afferent pathway abnormalities. Changes include decreased visual acuity, visual field alterations, abnormal visual evoked potentials, changes in the optic disc and nerve fiber layer of the retina, radiation retinopathy, and CNS injury. These changes occur in long term survivors of pediatric malignancy (especially those with prolonged, multimodal, and multicourse therapy), but they may be minimally symptomatic. The changes appear to be analogous to the CNS changes (leukoencephalopathy) described in patients with leukemia and attributed to multimodal therapy. By taking advantage of opportunities to detect adverse effects earlier in the treatment course, the present excellent cure rate may be improved by refinements in therapy that also improve the quality of survival.

Antineoplastic Agents↗
PubMed1984

Thermodynamic characterization of the pretransition of unilamellar dipalmitoyl-phosphatidylcholine vesicles.

High-sensitivity differential scanning calorimetry of small unilamellar vesicles (SUV) made by sonication of dipalmitoylphosphatidylcholine (DPPC) reveals that the gel-liquid crystalline transition at 37 C is preceded by a pretransition at 28 C that is relatively slow (t1/2 approximately equal to 2-4 min) and has an enthalpy change of ca. 0.2 kcal/mol. On incubation at 4 C, these SUV fuse spontaneously into large unilamellar vesicles (LUV). LUV also exhibit both a pretransition and a main-phase transition. The temperature of the main transition (Tm) and the enthalpy change of both the pretransition and main transition of these fused vesicles are similar to those of large multilamellar vesicles (MLV). The enthalpy change associated with the transition at 28 C decreases in SUV in a manner directly correlated to the decrease in the apparent enthalpy change of the 37 C main transition, indicating that the smaller (low temperature) transition is indeed a pretransition that is an inherent property of SUV. Therefore, unilamellar vesicles of DPPC appear to exhibit a pretransition at a temperature that varies from 28 C for the small vesicles to 35 C for the much larger vesicles.

Calorimetry, Differential Scanning↗
PubMed1983

The alternate expression of two restriction and modification systems.

Plasmids R124 and R124/3 carry genes coding for two different R-M systems and normally only one set of genes is expressed. These genes can be translocated to F plasmids that are compatible with the R factors and in strains carrying these F plasmids and an R factor a transacting regulatory mechanism switches off the expression of R-M genes on the introduced plasmid. Additionally the unexpressed genes on the introduced plasmid are expressed. The regulatory mechanism controlling the alternative expression of R124 and R124/3 R-M genes involves a physical rearrangement of DNA sequences.

Coliphages↗
PubMed1983

Synthesis of a spore-specific surface antigen during sporulation of Saccharomyces cerevisiae.

Antisera raised against purified yeast ascospores caused agglutination of both ascospores and vegetative cells. A spore-specific activity was obtained by absorbing out anti-vegetative activity with vegetative cells. The anti-vegetative cell activity was directed against mannan, and was probably due to exposure of some spore coat mannan at the spore surface since concanavalin A and lentil lectin also caused agglutination of ascospores. The spore-specific activity was probably determined by a protein or proteins, since extraction of spores with a mixture of sodium dodecyl sulphate and dithiothreitol markedly affected their agglutination by the spore-specific serum. The spore-specific antigen was synthesized in a soluble form during sporulation several hours before the appearance of the spore surface and the pool of soluble antigen declined as the spore was assembled. Synthesis of the soluble antigen was inhibited by adding cycloheximide at all times up to its first appearance in the sporulating cell.

Antigens, Surface↗
PubMed1977

Metabolic and EEG changes during transcendental meditation: an explanation.

Two experiments were conducted to measure the oxygen uptake (Experiment II) and the carbon dioxide production (Experiment I) during transcendental meditation. A control group of non-meditators and a few meditators listening to music was used for both experiments. In Experiment I, a controlled group of fasting meditators was also included. A drop in oxygen consumption and carbon dioxide production, found by previous authors during transcendental meditation, was confirmed. It was, however, possible to show that these drops were physiologically of small significance, and were of the magnitude to be expected from muscle relaxation. EEG recordings were taken during Experiment II in the meditating group. The EEG results showed transcendental meditation to be a method of holding the mediator's level of consciousness at stage 'onset' sleep. No evidence could be found to suggest that meditation produced a hypometabolic state beyond that produced by muscle relaxation and there was no evidence that the EEG changes were different from those observed in stage 'onset' sleep. No support was found for the idea that transcendental meditation is a fourth stage of consciousness.

Analysis of Variance↗
PubMedDate not supplied

A feasibility, toxicity, and early response study of etoposide, ifosfamide, and vincristine for the treatment of children with rhabdomyosarcoma: a report from the Intergroup Rhabdomyosarcoma Study (IRS) IV pilot study.

PURPOSE: The purpose of this study was to determine the feasibility, toxicity, and early response of patients with clinical group III rhabdomyosarcoma (RMS) to a chemotherapy regimen of etoposide (ETOP), ifosfamide (IFOS), and vincristine (VCR) with hyperfractionated radiation therapy (XRT). PATIENTS AND METHODS: Sixty-eight patients aged < 21 years, previously untreated, with clinical group III RMS or undifferentiated sarcoma with normal organ function were eligible for this study. Chemotherapy was as follows: weeks 0-8: IFOS 1.8 g/m2/day X 5 days every 3 weeks X 3 (with mesna), ETOP 100 mg/m2/day X 5 days every 3 weeks X 3, and VCR 1.5 mg/m2/week X 9; weeks 9-16: hyperfractionated XRT (except patients with parameningeal tumors with meningeal extension, who received XRT on day 0), IFOS/mesna weeks 9, 12, 16, and VCR weeks 9, 10, 11, 12, 16; weeks 20-99; IFOS/mesna q 3 weeks X 2, ETOP q 3 weeks X 2, and VCR weekly X 6 weeks. Four drug cycles were repeated every 9 weeks, beginning at week 29. In January 1991, the duration of therapy was reduced to 12 courses due to emerging evidence of IFOS-induced renal tubular dysfunction. RESULTS: Of the 62 patients evaluable for response, 45 (73%) achieved a complete response. There were three fatal toxicities due to infection. Life-threatening neutropenia was seen in 55 of 60 patients, and life-threatening infections occurred in 27 of 60 patients. Twenty-five patients (42%) developed some degree of neurotoxicity from vincristine. Eleven patients (18%) developed nephrotoxicity, 7 cases of which were severe; 6 of the 11 patients who developed nephrotoxicity were < 2 years old. CONCLUSIONS: This pilot study had toxicity and response rates comparable to the other two Intergroup Rhabdomyosarcoma Study (IRS)-IV pilot trials of vincristine-actinomycin-cyclophosphamide and vincristine-actinomycin-ifosfamide and is, therefore, being evaluated in the current IRS randomized trial. Due to the high incidence of life-threatening neutropenia and infections, the use of growth factors is now routine. Five of 11 patients who developed nephrotoxicity did so after more than eight courses of IFOS; therefore, the current randomized trial limits IFOS to a total of eight courses.

Adolescent↗