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Biomedical subjects

J Armitage

Publications and source records attributed to J Armitage.

At least 55 records · Page 3Linked to original sources
PubMed1990

Selective recognition of DNA antigenic determinants by murine monoclonal anti-DNA antibodies.

To assess the immune recognition of DNA in systemic lupus erythematosus, the antigenic specificity of monoclonal anti-DNA antibodies from autoimmune MRL-lpr/lpr mice was investigated Determinant specificity was assessed by ELISA in terms of binding to a panel of ssDNA antigens including calf thymus, human placenta, Escherichia coli, Clostridium perfringens, Micrococcus lysodeikticus, salmon testes, chicken blood and murine DNA. Among the monoclonal antibodies, a variety of binding patterns was observed, although for all antibodies tested murine DNA was among the most reactive antigens. Binding to other DNAs varied markedly, with some antibodies showing only low reactivity to certain antigens in the test panel. Similar results were obtained with sera of individual MRL-lpr/lpr mice. These results suggest that anti-DNA antibodies bind specific antigenic determinants variably expressed by DNAs of various species. Furthermore, the preferential binding to mouse DNA by some MRL-lpr/lpr antibodies may suggest a role of self-DNA in the in vivo selection of anti-DNA antibodies for expression.

Animals↗
PubMed1990

Overview of FK506 in transplantation.

FK506 is a potent immunosuppressive agent which is undergoing clinical testing in liver, kidney, heart, and bone marrow transplantation. It has been shown to effectively prevent and reverse ongoing rejection in these models. From the outset, FK506 was used with low-dose steroids to treat 110 primary liver, 30 heart, and 66 kidney graft recipients. FK506 was also used in the setting of complications related to CsA or to ongoing chronic or acute rejection. One hundred seventy-three liver, 21 kidney, 10 heart, and 11 bone marrow recipients were converted to FK506 and low-dose steroids, from a combination of CsA, steroids, and/or Aza. A randomized, prospective trial comparing FK506 with CsA in primary liver transplantation has verified the lower incidence of rejection and greater ease in treating rejection episodes, with fewer adverse effects. In summary, FK506 has proven to be an effective baseline immunosuppressive agent, as well as a dose-adjustable agent for the treatment of rejection.

Anti-Bacterial Agents↗
PubMed1989

Lessons learned in pediatric heart transplantation.

Between February 1, 1982, and June 30, 1988, 32 children underwent cardiac transplantation for treatment of congenital heart disease (10) and other cardiomyopathies (22). The 6-year actuarial survival was a disappointing 36% because of a high perioperative mortality (12 of 32, 37.5%) and because of five late deaths due to uncontrolable rejection. The perioperative mortality was a staggering 60% (6 of 10) for the patients with congenital heart disease. Four of the 6 recipients with congenital heart disease died because of acute failure of the donor right ventricle. This included 2 patients who required reconstruction of the pulmonary arteries for stenosis secondary to previous systemic-to-pulmonary shunts and 2 others in whom the pulmonary vascular resistances were underestimated because of undetected recent pulmonary emboli (1) and complicated pulmonary vascular anatomy (1). Five of the six late deaths were due to rejection-related events, and all were patients with acquired cardiomyopathy.

Actuarial Analysis↗
PubMed1989

Thymidylate synthesis and utilization via the de novo pathway in normal and megaloblastic human bone marrow cells.

We have measured the thymidylate synthetase activity of intact bone marrow cells using a 3H2O release assay. The mean thymidylate synthetase activity of vitamin B12- or folate-deficient megaloblastic marrow cells was reduced only in severely anaemic patients. There was a correlation between thymidylate synthetase activity and RBC in patients with megaloblastic haemopoiesis. The mean rate of incorporation into DNA of 6-3H deoxyuridine was similar in megaloblastic and normoblastic marrows. The rate of thymidylate synthesis exceeded its incorporation into DNA in all marrows, and the mean ratio between synthesis and incorporation was similar in normoblastic and megaloblastic patients, being independent of both thymidylate synthetase activity and RBC. Thus de novo thymine nucleotides were not utilized more efficiently in megaloblastic marrow cells. These data suggest that impaired thymidylate synthesis may not be the central defect in megaloblastic haemopoiesis, and that there is only a single pool of thymidine triphosphate in human bone marrow cells.

Anemia, Macrocytic↗
PubMed1989

The cardiopulmonary response to OKT3 in orthotopic cardiac transplant recipients.

Improvement in the outcome from cardiac transplantation can be attributed to recent advances in immunosuppression, including the use of OKT3, a new monoclonal antibody. The first dose of OKT3 induces side effects such as dyspnea in other transplant populations. We studied cardiopulmonary responses to OKT3 in 23 recipients of cardiac transplants. Despite pretreatment including antihistamines, hydrocortisone, and acetaminophen, OKT3 administered within 72 hours of transplantation, as part of prophylactic immunosuppression, induced a biphasic systemic response. Within the first hour, patients developed fever, hyperdynamia, hypertension, and tachycardia. By five to seven hours after the dose, there was mild hypotension, hypoxemia, and decreased indices of vascular resistance. Eighteen of the 23 patients required supplemental oxygen or vasopressor support (or both). Our findings define a complex cardiovascular response to OKT3 exhibited by the delayed noncoincident onset of hemodynamic instability, hypoxemia, and fever. Close observation in an ICU is recommended during the initial administration of OKT3 for prompt intervention when reactions occur.

Adult↗
PubMed1988

ChlVPP--an effective and well-tolerated alternative to MOPP therapy for Hodgkin's disease.

The substitution of chlorambucil for nitrogen mustard and vinblastine for vincristine has been suggested to be an equally effective and well-tolerated variation of the MOPP regimen (mechlorethamine, vincristine, procarbazine, and prednisone). We treated 76 patients with advanced (i.e., Stage III, IV, or II with bulky mediastinal mass) or recurrent Hodgkin's disease with chlorambucil 6 mg/m2, procarbazine 100 mg/m2, and prednisone 40 mg p.o. daily, all on days 1-14; plus vinblastine 6 mg/m2 i.v. on day 1 and 8 of each 28-day cycle (ChlVPP). There was no maximum dose of the myelosuppressive agents. Patients who had not previously been irradiated received from 2,300 to 4,100 cGY to sites of previously bulky diseases after completing 6 cycles of ChlVPP. ChlVPP was easy to administer (i.e., 87% of patients without previous chemotherapy received greater than or equal to 80% of the planned doses of myelosuppressive drugs) and was generally well tolerated, with only occasional vomiting from procarbazine and phlebitis from vinblastine. In patients without previous chemotherapy, 49 (76%) achieved a complete remission (CR) and 7 (11%) a stable partial remission (i.e., residual, stable radiographic abnormality). With a maximum follow-up of 4 years, only one CR has relapsed for an actuarial CR durability of 97%. ChlVPP with consolidative radiation therapy to sites of bulky disease is effective in advanced Hodgkin's disease and, compared with most other available regimens, is extremely well tolerated.

Adolescent↗
PubMed1986

In-vitro infection of chronic lymphocytic leukemia cells by Epstein-Barr virus (EBV).

We sought to determine the potential of infecting lymphoid cells from patients with chronic leukemia (CLL) with Epstein-Barr virus (EBV) by testing for EBV receptors (EBVR) by flow cytometry, assessing for infectability of these cells by culturing with B95-8-derived virus, and staining for EB nuclear-associated antigens (EBNA) at various times post-infection. EBVR were present on 54-91% of lymphoid cells in seven cases of CLL and on 46% of prolymphocytic leukemia cells. Dynamic changes regarding EBNA positivity, morphology, and viability occurred post-infection with the virus. On day 2 only a few EBNA-positive lymphoblasts were observed. On days 11-21 positivity increased from 2 to 34% of cells. Simultaneously, the viable cell number declined to approximately 1/10th of original number. A significant proportion of the EBNA-positive cells corresponded to the original CLL cells. In 3 of 7 cases of CLL a Pan T-cell phenotype was demonstrated by Leu-1 monoclonal antibody testing. The infected cells did not react with two monoclonal antibodies, EBV-CS 1 and 4, which react with B-cell lymphoblastoid cell lines (B-LCL). Moreover, the B-LCL derived at 1-2 months post-infection of CLL cells did not express the Leu-1 antigen, but expressed EBV-CS 1 or 4 defined antigens. In the prolymphocytic leukemia, 64% of the cells showed EBNA positivity on day 7 and giant cells with huge round or multiple nuclei appeared which were EBNA-positive. CLL and prolymphocytic leukemia cells can be infected as demonstrated by EBNA-positivity. This infection does not lead to immediate transformation, but evokes lymphoblast and multinucleated giant cell production prior to the death of cells.

Aged↗
PubMed1986

High-dose melphalan and total body irradiation with bone marrow transplantation for refractory malignancies.

We investigated if high dose melphalan and total body irradiation could be administered to adult patients with acceptable toxicity. Nineteen adult patients with relapsed disease, 15 of them having hematologic malignancies, were treated with high-dose melphalan (100 mg/m2-140 mg/m2) divided over 2 consecutive days followed by a rest period of 4 days before receiving total body irradiation, 850 rad administered in five fractionated doses over 3 days. Subsequently 11 patients received autologous, seven allogeneic and one syngeneic, bone marrow transplantation. All patients had severe myelosuppression and the major extramedullary toxicity was mucositis. There were three early deaths, two related to septicemia and one to graft-versus-host disease with associated cytomegalovirus pneumonitis. All patients were heavily pretreated, and 16 were demonstrating progressive disease on alternative salvage therapies at the time of bone marrow transplantation. Two of the 16 evaluable patients (12.5%) achieved complete remissions, and 10 (63%) achieved partial remissions for a total response rate of 75%. One patient is a long-term disease-free survivor (over 1 yr). An occasional patient may be cured by this approach. The combination of melphalan, an alternative alkylating agent to cyclophosphamide and total body irradiation are associated with moderate gastrointestinal toxicity in heavily pretreated adult patients. The combination warrants further investigation in a less heavily pretreated population to determine more accurately the complete response rate.

Adult↗
PubMed1979

Carbon-coated subperiosteal dental implants for fixed and movable prostheses.

Subperiosteal dental implants are not intended to replace conventional dentistry but provide an alternative method of treatment for the patient who cannot otherwise tolerate a dental prosthesis. Success can be achieved in the maxillae and in the mandible without the risk of serious complications. There are good prospects for a long-term favorable prognosis when appropriate surgical and prosthodontic criteria are observed.

Carbon↗
PubMed1977

Immunoblastic lymphadenopathy with pulmonary infiltrates, hypocomplementemia and vasculitis. A hyperimmune syndrome.

A detailed description of the clinical and morphologic characteristics of four patients with immunoblastic lymphadenopathy, pulmonary infiltrates, hypocomplementemia and vasculitis is presented. Noteworthy in the patients described here is the clinical similarity to patients with collagen-vascular diseases and systemic drug reactions. The frequent occurrence of pulmonary symptoms, bilateral interstitial infiltrates and pleural effusions is emphasized. The morphology suggests stimulation of the immune system by antigenic agents, and the low complement levels and the presence of vasculitis suggest that circulating immune complexes may be present. Immunoblastic lymphadenopathy may represent a syndrome in which the adenopathy is but a nonspecific part of a systemic hyperimmune response to unknown antigens. The clinical course of the patients reviewed suggests that supportive treatment and corticosteroids constitute the safest therapeutic approach.

Adult↗