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Biomedical subjects

I R Walker

Publications and source records attributed to I R Walker.

31 records · Page 2Linked to original sources
PubMed1985

Association of renal failure with Lewis incompatibility after allogeneic bone marrow transplantation.

The cause of the renal failure that occurs in approximately 20 percent of patients following allogeneic bone marrow transplantation is poorly understood. A patient is described in whom acute renal failure occurred one week after allogeneic bone marrow transplantation. The onset of the renal failure was associated with the demonstration of anti-Lewis antibodies in the patient's serum, which could only have been derived from donor lymphocytes. Recovery of renal function coincided with the disappearance of the Lewis antibody. It is postulated that Lewis incompatibility between graft and host tissue may have contributed to the renal failure in this patient and that incompatibility associated with determinants present on renal cells may account for other instances of acute renal failure following allogeneic bone marrow transplantation.

Acute Kidney Injury↗
PubMed1985

Simultaneous or sequential expression of lymphoid and myeloid phenotypes in acute leukemia.

Acute mixed myeloid-lymphoid leukemia is uncommon. We report four cases in which myeloid and lymphoid cell markers were observed simultaneously or sequentially when 94 patients with acute leukemia were phenotyped according to the French-American-British (FAB) classification system, with cytochemical stains, and with immunologically defined differentiation markers (identified by monoclonal antibodies and antiterminal deoxynucleotidyl transferase [TdT]). In one case, conversion from acute lymphoblastic leukemia to acute myeloid leukemia was noted (FAB L1, TdT+ to FAB M4, Auer rods, TdT-). In another patient, two distinct populations of myeloid and lymphoid blast cells were observed simultaneously (TdT-, LeuM1+/TdT+, LeuM1-). In two additional patients, acute leukemia was characterized by the expression of both lymphoid and myeloid markers on the same cell (TdT+/Leu M1+, B4+/Leu M1+ and greater than or equal to 70% TdT+, T11+, My9+). The Philadelphia (Ph1) chromosome was negative in all cases, though other chromosomal abnormalities were noted in three out of four cases. Malignant transformation of a pluripotential stem cell for both lymphoid and myeloid lineages, with or without the Ph1 chromosome marker, could explain the coexistence of distinct populations of lymphoblasts and myeloblasts in acute leukemia. Acute leukemia with a biphenotypic profile may reflect genome depression accompanying neoplasia.

Adult↗
PubMed1983

Factors XI and XII are low in subjects with liver disease.

We prospectively measured levels of factors XI and XII in parallel with other coagulation factors in 39 unselected patients with liver disease and in 20 control subjects. Mean levels of factors XI and XII in subjects with liver disease were significantly reduced, being 58% and 61%, respectively, compared with 100% and 94% in controls. Reductions in levels of factors XI and XII were most pronounced in those subjects with low serum albumin. The partial thromboplastin time (APTT) reflected low levels of either factor XI or XII and was most prolonged when both were low, but cause and effect was not demonstrated. Low levels of these factors may explain previous reports of poor response of APTT to infusions of prothrombin complex concentrates. Finally, these low levels strongly suggest that factors XI and XII are produced in the liver.

Blood Coagulation Factors↗
PubMed1982

The treatment of acute myelocytic leukemia in patients 30 years of age and younger.

The treatment of acute myelocytic leukemia in childhood and young adults has lagged behind that for acute lymphocytic leukemia. The studies described here were directed towards evaluating the role of intensive chemotherapy in the treatment of this illness. Intensive remission induction therapy combining cytosine arabinoside with an anthracycline antibiotic produced a complete remission rate comparable to that achieved in acute lymphocytic leukemia (45 of 49 patients or 92%). Intensive consolidation chemotherapy produced a median duration of complete remission of 160 weeks with 40% of patients projected to be in remission at 4 years. By contrast, the median duration of remission for patients treated with moderate consolidation/maintenance therapy was 23 weeks with only 10% of patients in remission at 4 years. These studies demonstrate that intensive chemotherapy can be administered to pediatric patients and young adults and that this approach to therapy produces a high remission rate with a 3 year median duration of remission.

Adolescent↗
PubMed1980

Thrombocytopenia in septicemia: the role of disseminated intravascular coagulation.

The mechanism of isolated thrombocytopenia in septicemia is unknown, but compensated disseminated intravascular coagulation (DIC) has been suggested as a possible cause. To investigate this possibility, platelet counts and sensitive assays for in vivo thrombin and plasmin generation, including fibrinogen gel chromatography and fibrinopeptide A (FPA) assays, were obtained on 31 septicemic patients. Fifteen of 17 patients with gram-negative septicemia and 8 of 14 patients with gram-positive septicemia had thrombocytopenia. Platelet survival studied demonstrated a decreased platelet survival. In 11 of 12 patients with severe thrombocytopenia (platelet count less than 50,000mul), there was laboratory evidence of intravascular coagulation. In contrast, there was little evidence of intravascular coagulation in 8 of 11 patients with moderate thrombocytopenia (platelet counts 50,000 to less than 150,000/mul) or in 7 of 8 patients with normal platelet counts. This report indicates that while DIC accompanies thrombocytopenia in many patients with severe thrombocytopenia, there is frequently little evidence for intravascular coagulation in patients with moderate thrombocytopenia. It is apparent that factors other than intravascular thrombin must play a role in producing the thrombocytopenia of septicemia.

Adult↗
PubMed1974

Lymphoma with hypercalcemia.

A prospective survey was carried out to determine the incidence of hypercalcemia in hospitalized patients with lymphoma. Serum calcium determinations were carried out during 440 admissions on 152 patients, most of whom had widespread lymphoma. Forty-one of the 152 patients died, all having had calcium levels recorded on that admission. Two of the 152 patients (1.3%) were found to have hypercalcemia. By comparison hypercalcemia occurred in 6 of 34 patients (17.6%) with multiple myeloma.Hypercalcemia is uncommonly associated with lymphoma but may be seen particularly in centres where many patients with this disease are treated. Hypercalcemia readily responds to therapy and is a reversible cause of morbidity, but when associated with lymphoma it usually indicates widespread disease. The mechanism of hypercalcemia is unknown but there is strong evidence for humoral factors that may or may not be related to parathyroid hormone.

Adolescent↗
PubMed1973

Hemoglobin abnormalities in neoplastic hematological disorders.

Fetal hemoglobin (F) and hemoglobin A(2) were estimated in 35 patients with malignant hematological disorders. In 9 out of 10 patients with morphological and cytochemical features of acute myeloblastic leukemia the hemoglobin F was greater than 2%. Of the other 25 patients investigated only one patient with polycythemia rubra vera had a hemoglobin F level of more than 2%. Estimation of fetal hemoglobin may be of value in the classification of acute leukemias and the increased level observed probably reflects disturbed hemoglobin synthesis in the acute myeloblastic type.

Adolescent↗
PubMed1971

Simple atrophic gastritis and gastric carcinoma.

Gastric carcinoma was detected nine, 10, 18, and 21 years after the biopsy diagnosis of atrophic gastritis in four patients of a group of 40. The gastritis was presumed to be of the simple type. Tests of vitamin B(12) absorption in three patients gave normal results, no gastric autoantibodies were detected in the two patients tested, in all patients histological examination of the gastrectomy specimens revealed a multifocal gastritis differing from the diffuse gastritis of pernicious anaemia and in three patients the gastritis affected the antrum, which is unusual in pernicious anaemia. The 10% incidence of gastric carcinoma in 40 patients with simple atrophic gastritis followed for a mean period of 15 years is equivalent to that previously described in pernicious anaemia. However, in view of the relative incidence of atrophic gastritis with and without pernicious anaemia in the general adult population, it emerges that atrophic gastritis without pernicious anaemia is numerically the more important precursor of gastric carcinoma.

Adult↗