Biomedical subjects
Publications and source records attributed to D J Pritchard.
Pathologic fractures of the humerus create serious management problems. Impending fractures often can be anticipated. Fixation of impending or established fractures may provide significant benefits: comfort, improved functional ability, and facilitation of nursing care.
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The observation that mothers of cystic fibrosis patients come from sibships that are larger than those of the fathers is explained by a decrease in sex ratio with increasing size of parental sibships. This feature also provides the basis for a new theory for the dissemination of the major mutant allele, deduced to have arisen 2,700-5,000 years ago, in accordance with an overall heterozygote advantage of around 3%. In heterozygous women with heterozygous partners, sex-related selection probably occurs after fertilization.
Telangiectatic osteosarcoma is a rare variant of osteosarcoma. In the original report from the authors' institution, a poor prognosis was noted. The authors have updated their experience with this entity. The prognosis for patients with telangiectatic osteosarcoma has improved remarkably. The prognosis in the present series seems to be the same as that for conventional osteosarcoma. Adjuvant chemotherapy seems to help in salvaging patients with metastatic disease. However, in this small series, survival of patients without metastasis is apparently not influenced by whether they received chemotherapy.
Advances in the treatment of Ewing's sarcoma have been dramatic. Present treatment protocols control local disease by radiotherapy, surgery, or both; systemic spread is limited by aggressive multiagent chemotherapy. In patients with localized osseous Ewing's sarcoma, five-year survival rates now range from 54% to an estimated 74%. With late relapse not uncommon, control of the primary lesion is critical to long-term survival. Several studies now show improved local control and possibly improved survival of patients with surgical treatment of primary osseous Ewing's sarcoma.
We studied selective in vivo and in vitro immunologic factors of 25 patients with choroidal malignant melanoma. Immune profile factors did not show consistent differences between patients with melanoma and an age-matched control population. The studies were also non-contributory in delineating variations in immunocompetence with respect to melanoma cell types. Serial immune profiles failed to identify a change when clinical evidence of metastasis developed. When tested as a group, patients with melanoma in whom metastatic disease developed during the study showed significant depression of initial mitogen-induced lymphocyte blastogenesis. This depression was noted in advance of clinically recognized metastatic disease. This group had a wide range of responses that overlapped those of control patients, thus making the usefulness of these testing factors questionable for individual prognosis or for clinical monitoring.
Based on evaluation of the rehabilitative needs of patients who have had a leg amputated because of cancer, an amputee visitor program was developed. The visitor is a cancer amputee who has successfully completed rehabilitation. About 5 days after a patient's amputation, the visitor sees the patient, telling of personal experiences, answering the patient's questions, and showing the prosthesis. The visitor later evaluates the visit on a data collection sheet. From 1 to 6 months after the visit, the patient and, if possible, a relative are interviewed to determine their long-term reaction to the program. During a 30-month period, 65 new patients were seen and evaluated by two visitors. Sixty (92%) responded favorably to the visit. In follow-up interviews with 36 patients, 33 (92%) said the visit substantially improved their outlook. In summary, our data indicate that the amputee visitor contributes significantly to rehabilitation.
Limb-saving resection has become a valid alternative to amputation in carefully selected patients with bone tumors. As interest grows in this technique, efforts continue to improve our methods of bone and joint reconstruction to restore a functional extremity. Previously there was little interest in this form of treatment despite a limb-saving potential, because of inadequate methods of skeletal reconstruction. The purpose of this paper is to review these previous methods and to outline our present approach to the problem.
To determine whether immediate or delayed lymphadenectomy is more beneficial than none in cases of localized (stage I) melanoma, we undertook in 1972 a prospective randomized study. Patients with midline trunk lesions were excluded as well as patients with lesions situated directly over the node-bearing area. In addition, because of the low risk of metastasis, the protocol was changed to exclude level 2 lesions. Of the 173 patients studied, 63 were randomized to no lymphadenectomy, 56 to delayed (3 months) lymphadenectomy, and 54 to immediate lymphadenectomy. None of these regimens differed significantly from the others in its effect on length of survival or interval to metastasis. And of the 110 patients who underwent elective lymphadenectomy, 103 were without nodal involvement. Our preliminary conclusion is that elective node dissection is not beneficial in management of melanoma. However, disease progression was advanced significantly by age of the patient (greater than 60 years) and by invasiveness (level 4 or 5) and thickness (greater than 1.5 mm) of the melanoma.
The clinical findings in 262 patients with melanoma were correlated with an assessment of their cellular-mediated immunity by delayed-type hypersensitivity (DTH) skin tests, by lymphocyte blastogenesis, and by leukocyte enumerations. Patients with systemic metastases (stage IV) and those with evidence of tumor burden had fewer positive DTH reactions for recall antigens than did patients with localized disease (stage I), patients with no evidence of tumor burden, and 227 normal controls. However, no differences were found in the magnitude of response among patients with melanoma or when compared with controls. Patients with melanoma had fewer responses to dinitrochlorobenzene (40% than did controls (98%), but there were no differences by stage or tumor burden. Similarly, blastogenesis in the presence of PHA, Con A, and PWM was depressed when compared with controls, but there was no meaningful correlation with the clinical status. Leukocyte, T cell, or B cell counts revealed no alteration from normal for the patients with melanoma. The usefulness of these studies for routine clinical monitoring is questioned.
After nodal metastasis from malignant melanoma, approximately 80% of patients die from disseminated disease. To clarify the role of radiation therapy (XRT) following node dissection. 56 patients with biopsy-proven nodal metastasis participated in a randomized, prospective clinical trial which compares radiation therapy to the regional lymph node area following lymphadenectomy (27 patients) with lymphadenectomy alone (29 patients). Interesting differences in the survival curves (p = 0.09) and in the disease-free interval curves (p = 0.08) for the two treatment groups proved to be attributable to imbalances in the age and nodal distributions in the treatment groups. Covariate analysis identified age and sex as the factors having the most significant (p less than 0.04) effect on survival and identified the number of positive nodes as the covariate having the most significant (p less than 0.02) effect on disease-free interval. Treatment did not have a significant effect upon survival or disease-free interval.
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Osteogenic sarcoma continues to present a tremendous therapeutic challenge. Until recently, treatment has continued at a relatively unsophisticated level. Although amputation, usually at a cross-bone level with a safe margin above the lesion, continues to be the treatment of choice, increased interest is being demonstrated in radical en bloc limb-saving resections. Modern joint implants are proving effective in restoring the osseous integrity and joint function after the resection.
Over a three year period, 28 children or young adults up to 20 years of age underwent 60 thoracotomies for pulmonary metastatic osteogenic sarcoma. These patients also received adjuvant chemotherapy. Sixteen of the 28 patients are currently alive and 13 of these are free of disease. The patients have been followed for 6 to 48 months after the initial thoracotomy; median survival is 25 months. Actuarial survival curves produced a 4 year survival of 57%. Although a tumor-free interval of more than 1 year greatly enhanced survival, three patients survived with tumor-free interval of 6 months or less. Patients with disease confined to one lobe at the initial thoracotomy did very well, and yet survivors were seen when disease involved more than one lobe or was bilateral. An aggressive surgical approach toward the pulmonary metastases thus appears to be justified.
Survival of patients with primary osteosarcoma who received traditional surgical management has been very poor. Several studies have reported the percentage of patients alive 3 years after first treatment to be between 20 and 25%. In a study of such patients first treated at the Mayo Clinic between Jan. 1, 1963, and July 1, 1974, the survival noted in the first few years was typical of that of other reports, about 25%. However, by 1972 through mid-1974, the 3-year survival had become 50%. This improvement was not the result of adjuvant treatment or any basic change in type of patient treated, yet it is similar to that reported in connection with some of the new adjuvant therapies used in trials depending on historical controls. Our results cast doubt on findings made in the absence of concurrent, randomly selected controls.
A randomized study compared the effects of combination chemotherapy (high-dose methotrexate, adriamycin, and vincristine) with immunotherapy in the form of transfer factor in the adjuvant treatment of patients with nonmetastatic osteogenic sarcoma after apparent complete surgical ablation of the primary tumor. Thirty-two patients were evaluated. Of 22 patients who received chemotherapy, three died of drug-related complications and six were alive without disease recurrence between 260 and 673 days after operation. Ten patients in the transfer factor group converted their markers, and of these, five were alive without recurrence 420--753 days after operation. Neither treatment program was considered superior with respect to disease-free survival.