Biomedical subjects

C Civin

Publications and source records attributed to C Civin.

22 records · Page 2Linked to original sources

PubMed1989

Intermediate-dose intravenous methotrexate and mercaptopurine therapy for non-T, non-B acute lymphocytic leukemia of childhood: a Pediatric Oncology Group study.

Methotrexate (MTX) and mercaptopurine (MP) are the mainstays of continuation therapy for acute lymphocytic leukemia (ALL). These drugs are stored in tissues as active metabolites. Relapse in ALL might reflect failure to achieve adequate intracellular drug levels. Assured (parenteral) delivery of higher doses of MTX and MP should maximize tissue levels of these drugs by overcoming individual variations in absorption, metabolism, clearance, and compliance. Fifty-nine children with ALL at lower risk of relapse received 12 intensive MTX/MP courses immediately after 4 weeks of standard vincristine, prednisone, and asparaginase induction. Each 2-week intensive course included: MTX, 200 mg/m2 intravenous (IV) push then 800 mg/m2 IV over 24 hours on day 1; MP, 200 mg/m2 IV push then 800 mg/m2 IV over 8 hours on day 2; MTX, 20 mg/m2 intramuscularly on day 8; and MP, 50 mg/m2 orally daily on days 8 to 14. After the 6 months of intensive therapy, continuation therapy was weekly MTX/MP (as on days 8 to 14) for 1 or 2 years. Age-based MTX was given intrathecally (IT) for CNS prophylaxis. All patients entered remission. Three patients relapsed: bone marrow (at 24 and 37 months), and bone marrow and CNS (at 34 months). There were no isolated CNS relapses or deaths in remission. Event-free survival at 4 years is 94% (SE, 7%) by Kaplan-Meier analysis. Toxicities (infection, mucositis) occurred in less than 10% of intensive MTX/MP courses. However, a child with Down's syndrome withdrew after three courses because of recurrent severe mucositis. Further studies of this regimen are in progress.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1989

Osteoclast-like cells formed in long-term human bone marrow cultures express a similar surface phenotype as authentic osteoclasts.

Long-term cultures of human bone marrow form multinucleated cells (MNC) with many functional characteristics of osteoclasts including: expression of tartrate-resistant acid phosphatase, appropriate responses to osteotropic hormones, calcitonin-induced contraction and formation of resorption lacunae on calcified matrices. However, it is unclear if these cells express similar surface antigens as expressed by authentic osteoclasts, since they form on plastic surfaces in the absence of bone. Bone may be required to complete the differentiation process for osteoclasts. Therefore, we have examined the surface phenotype of MNC and compared it with that of osteoclasts freshly isolated from bone, to determine if MNC express similar surface antigens, and if MNC express antigens which identify their cellular origin. Similar to bone-derived osteoclasts, MNC formed in long-term human bone marrow culture expressed osteoclast-specific antigens (detected by monoclonal antibodies 13c2 and 23c6) and did not express Fc receptors, T cell specific antigens, most myeloid antigens or mature macrophage antigens. In contrast to authentic osteoclasts, MNC reacted with a monoclonal antibody (Mol) which identifies an antigen present on myeloblasts, monocytes, granulocytes, and null cells from human peripheral blood and bone marrow. MNC also reacted with the monoclonal antibody My11, which is present on CFU-GM, the granulocyte-macrophage colony-forming cell, the probable precursor for MNC. These data demonstrate that MNC formed in long-term human marrow cultures express a similar surface phenotype to osteoclasts. This phenotype is different from that expressed by macrophage polykaryons. In addition, MNC also expressed monocyte-related antigens (My11, Mol), suggesting that are derived from or related to the monocytic lineage.

Animals↗

PubMed1985

Life-threatening airway obstruction as a complication to the management of mediastinal masses in children.

Life-threatening airway obstruction from large mediastinal masses in children poses a difficult diagnostic and therapeutic dilemma, requiring the close coordination of a pediatric surgeon, anesthesiologist, radiologist, and oncologist. To focus on this problem, the anesthetic and surgical management of 50 consecutive children with mediastinal masses treated between 1978 and 1984 were reviewed. Thirty children presented with respiratory symptoms; nine had life-threatening respiratory compromise with dyspnea, orthopnea, and stridor. Thirteen of these symptomatic children had marked compression of the trachea and/or mainstem bronchi on radiographic studies. The tracheal cross-sectional area which was measured by computed tomography was decreased by 35% to 93% of the normal tracheal dimensions in these children. Nonresectable malignant neoplasms including lymphoma, Hodgkin's disease, rhabdomyosarcoma, and neuroblastoma were the eventual diagnoses in 10 of these patients. The other 3 patients were less than 4 years old and had benign lesions. General anesthesia was judged to be prohibitively risky in 5 of 13 patients. The diagnosis was established by node or needle biopsy under local anesthesia, and general anesthesia was deferred until the compromised airway was alleviated by radiation and chemotherapy. General anesthesia with endotracheal intubation was administered to 8 patients, 5 of whom developed total airway obstruction. Using a variety of maneuvers, ventilation was reestablished in all 5 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

PubMed1984

Monoclonal antibody localization of A and B isoantigens in normal and malignant fixed human tissues.

The expression of human blood group A and B isoantigens in normal and malignant tissues from stomach, colon, and pancreas was analyzed in an immunoperoxidase assay using monoclonal antibodies specific for these isoantigens. Appropriate isoantigen expression was demonstrated in the normal epithelium from the stomach, pancreas, and proximal but not distal colon of blood group A, AB, or B patients. Half of all gastric carcinomas and of proximal colon carcinomas showed complete loss of isoantigen, whereas the adjacent mucosa in these cases continued to express appropriate isoantigen. Isoantigen expression was completely lost in only 13% of pancreatic carcinomas tested. Neither A nor B isoantigen was detected in normal epithelium from the distal colon. By contrast, 85% of carcinomas derived from this site showed reexpression of isoantigen. Inappropriate expression of A isoantigen was detected in pancreatic carcinomas (2/5) but not in gastric or colon carcinomas (0/21). Inappropriate expression of B substance was not detected in any tissue (0/38). Interestingly, differential binding of antibodies to Type 1 versus Type 2 and/or difucosyl versus monofucosyl blood group B substances was manifested by differences in intensity of staining for endothelium and red blood cells.

ABO Blood-Group System↗