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Biomedical subjects

C Restrepo

Publications and source records attributed to C Restrepo.

At least 37 records · Page 2Linked to original sources
PubMed1986

Pathological tissue changes following intraoperative radiotherapy.

Ninety patients with a variety of advanced-stage malignancies were treated with surgical resection, when feasible, and with intraoperative radiotherapy. Certain patients received additional external beam radiotherapy. During clinical follow-up, 45 patients died. Twenty-two patients (49% of deaths) underwent detailed autopsies between 1 and 18 months after treatment, with special attention directed towards assessing radiation damage to various tissues. Histological changes related to radiation were generally manifested as fibrosis. Mild fibrotic changes in retroperitoneal soft tissues and mild hypocellularity in vertebral bone marrow were consistently present in patients treated for pancreatic carcinoma, gastric carcinoma, and retroperitoneal or pelvic sarcomas. Fibrosis of the soft tissues of the porta hepatis without narrowing of the bile duct was present in patients treated for pancreatic or gastric cancer. perineural fibrosis was present in retroperitoneal and pelvic nerve trunks in patients treated for abdominal or pelvic sarcomas and in patients treated for unresectable carcinoma of the pancreas. Significant radiation-related changes were generally not observed in major blood vessels, intestine, or ureter. Intact irradiated primary tumors consistently displayed necrosis.

Autopsy↗
PubMed1986

Comparative pathology of cardiac neoplasms in humans and in laboratory rodents: a review.

This review deals with the frequency, heredity, and morphology of 19 different histologic types of cardiac tumors that may affect humans, rat, mouse, guinea pig, and mastomys. Chemicals, durable fibrous materials, viruses, and probably irradiation have induced cardiac tumors in rodents. Apart from the involvement of asbestos in the induction of pericardial mesothelioma, no carcinogens have been identified in induction or promotion of cardiac tumors in humans. A hereditary tendency for the occurrence of myxoma and aortic paraganglioma has been indicated in humans as well as strain-specific heredity for rhabdomyoma in the guinea pig and for atriocaval node tumor in the rat.

Animals↗
PubMed1985

Dissociation between adrenocorticotropin and corticosterone responses to restraint after previous chronic exposure to stress.

The effect on emotional reactivity produced by a model for chronic stress in which different types of acute stresses were randomly combined for 29 days was studied in adult male rats. Chronically stressed rats showed a slight decrease in body weight gain and an increase in relative adrenal weight. Chronic stress did not modify defecation rate but reduced exploratory activity in the holeboard. Neither basal nor acute-stress induced levels of adrenocorticotropin (ACTH) were modified by previous chronic stress. Likewise, basal corticosterone levels were similar in both groups. However, corticosterone response to acute restraint stress was higher in chronically stressed than in control rats. The mechanisms underlying the dissociation between ACTH and corticosterone as well as its possible implications are discussed.

Adrenocorticotropic Hormone↗
PubMed1985

Patterns of recurrence in patients with high-grade soft-tissue sarcomas.

From July 1975 to December 1982, 563 patients were referred to the Surgery Branch of the National Cancer Institute with the diagnosis of soft-tissue sarcoma. Three hundred and seven of these patients had fully resectable, localized high-grade soft-tissue sarcomas and were treated at the National Cancer Institute using standard protocols with surgery alone, or in combination with chemotherapy and/or radiotherapy. An aggressive surgical approach was undertaken in the management of patients who subsequently developed recurrent disease. These 307 cases have been reviewed, with a median duration of follow-up of 30 months, to determine the frequency of recurrent disease, the patterns of recurrence, and the impact of surgery on the survival of patients who developed recurrent disease. Disease recurred in one hundred seven patients (107/307, 35%), with a median disease-free interval of 18 months (range, 0.5 to 72.0 months). The frequency of recurrence by site of primary sarcoma was extremity, 31% (65/211); head and neck, 33% (4/12); trunk, 40% (17/42); retroperitoneum, 47% (17/36); and breast, 67% (4/6). Isolated pulmonary metastatic disease was the most common pattern of initial recurrence (56/107, 52%) followed by isolated local recurrence (21/107, 20%). Single other sites of recurrence and multiple concurrent sites of recurrence each accounted for 14% (15/107) of all initial recurrences. The relative frequency of each of these four patterns of recurrence varied with the site of the primary sarcoma. The outcome for patients with recurrent disease depended on the site of recurrence, rather than on the site of the primary sarcoma. Sixty-six patients (66/107, 62%) with recurrent disease were rendered surgically disease-free with the first recurrence, including 40 (40/56, 72%) patients with isolated pulmonary metastases, 20 patients (20/21, 96%) with isolated local recurrences, five patients (5/15, 33%), with isolated other sites of recurrence and one patient (1/15, 7%) with multiple sites of initial recurrence. Following surgical resection, the actuarial three-year survival for the 66 patients rendered disease-free was 51%. The median survival for the 41 patients not rendered surgically disease-free with the first recurrence was only 7.4 months. Thirty of the sixty-six patients (30/66, 45%) rendered disease-free with the first recurrence remained disease-free at follow-up, with a median follow-up of 28 months from the time of resection of the first recurrence. The remaining 36 patients (36/66, 55%) subsequently recurred, with a median disease-free interval of 7.3 months.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1984

Immunocytochemical enhancement of basement membrane antigens by pepsin: applications in diagnostic pathology.

Basement membrane zone antigens, laminin, Type IV collagen, and Type V collagen each are enhanced selectively in formalin-fixed, paraffin-embedded sections by pretreatment with pepsin (1 mg pepsin/mL 0.5 M acetic acid). Highly specific antibodies to laminin, Type IV collagen, and Type V collagen each demonstrate intense linear staining of epithelial and endothelial basement membranes in fresh tissue, but this staining is diminished markedly and often completely abolished in paraffin-embedded tissue. Pretreatment of this paraffin-embedded tissue with standard immunoperoxidase enhancement technics such as trypsin fails to increase immunoreactivity of these antigens. Pretreatment with other proteases with known collagenolytic activities such as bacterial collagenase and Type IV collagenase is likewise ineffective. In contrast, pepsin pretreatment markedly enhances immunoreactivity of laminin, Type IV collagen, and Type V collagen. Previous immunocytochemical studies of the basement membrane useful in the distinction of invasive tumors from their benign counterparts, for example, tubular carcinoma of the breast from sclerosing adenosis, which only could be done prospectively in fresh tissue now can be performed retrospectively in paraffin-embedded tissue.

Adenocarcinoma↗
PubMed1984

Analysis of antigenic expression by primary and autologous metastatic human sarcomas using murine monoclonal antibodies.

The efficacy of monoclonal antibody therapy depends in part on the expression of the relevant tumor-associated antigens by both primary tumors and their metastases. Antigen expression by paired primary and autologous metastases from surgically excised osteogenic and soft-tissue sarcomas from 15 patients was studied using a panel of murine hybridoma monoclonal antibodies and indirect immunoperoxidase staining of formalin-fixed tissue sections. The panel included three antibodies (B3619, 17-9H3, OST6) recognizing sarcoma-associated antigens and an antibody recognizing an HLA-DR framework determinant (OKla1). In most cases, antibody binding to both primary and metastatic tumors was observed. However, marked heterogeneity of binding intensity between primary and metastatic tumors and of cells expressing antigens within tumors was noted. This occurred even though primary and metastatic tumors demonstrated homogeneous histology and cellular morphology. Differences were noted among patients as well as among metastases taken from an individual. A significant number of both primary and metastatic tumors contained cells that did not bind a particular antibody even in the presence of other cells that demonstrated significant antibody binding. Thus, strategies for single monoclonal antibody therapy may be limited by heterogeneity of intertumor and intratumor antigenic expression.

Animals↗
PubMed1984

Atherosclerosis and lipid composition of the abdominal aorta. Comparison of autopsied New Orleans and Guatemalan men.

Abdominal aortas from 78 Guatemalan men and 79 New Orleans white men were examined for lipid composition and for the extent of grossly visible atherosclerotic lesions. In the specimens examined, atherosclerotic lesions were more extensive in New Orleans than in Guatemala, confirming findings of studies performed 10 and 20 years earlier. Lipid accumulation differed greatly between the geographic locations with new Orleans specimens having more chemically determined lipids. Differences in lipid accumulation between New Orleans and Guatemala are more striking when expressed in terms of content (milligrams per 100 square centimeters than when expressed as concentration (milligrams per gram of dry defatted weight). Chemical analyses indicate that lipid accumulation in the aorta results principally from the atherosclerotic process rather than from aging. In the 15- to 24-year age group, the gross extent of fatty streaks was similar in both populations, but content and concentration of free cholesterol was significantly higher in New Orleans specimens than in Guatemalan specimens. This finding might be related to the more extensive development of raised lesions at later ages in New Orleans subjects.

Adolescent↗
PubMed1979

Geographic comparisons of diffuse intimal thickening of the aorta.

Aortic intimal thickness was measured microscopically in samples taken from areas grossly free of atherosclerotic lesions of 2,472 subjects aged 15 through 64 years collected during the first year of the International Atherosclerosis Project (IAP). Results indicate that there is progressive increase in aortic intimal thickness with increasing age in both sexes. No differences were observed between the upper thoracic and abdominal aorta. Mean intimal thickness does not appear to be consistently thicker in males than in females. Some differences were found in mean thickness among the 19 location--race groups included; however, such differences did not parallel those observed among the same location--race groups by the mean level of atherosclerosis. A few subjects with Coronary Heart Disease (CHD) and atherosclerosis-related cases had slightly thicker intimas. Diffuse Intimal Thickening (DIT) detected grossly correlates well with thicker means of intimal thickness in both sexes in the abdominal aorta and the thoracic aorta in females. DIT appears to be a universal phenomenon mainly age-dependent; it also appears to be increased in some (CHD) and atherosclerosis-related conditions.

Adolescent↗