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Biomedical subjects

W Krivit

Publications and source records attributed to W Krivit.

At least 127 records · Page 7Linked to original sources
PubMed1982

Filtration deformability of rabbit pulmonary macrophage.

Rabbit PAM deformability was evaluated by positive-pressure filtration through Nucleopore membranes of well-specified pore diameter. The PAM filtration method was standardized and was influenced by apparatus variations (pore size, flow rate, cell concentration), environment (temperature, pH, divalent cations, protein concentration), and differences in PAM cell volume. The influence of phagocyte function on filtration deformability was evaluated by exposing PAMs to pharmacologic and physiologic agents with somewhat exclusive influences on phagocyte physiology. Agents that interact with microfilament contractile protein (N-ethylmaleimide, cytochalasin B) altered deformability profoundly, but no effect was observed with agents interacting with microtubules (vinblastine, colchicine). Agents that cause general PAM activation (phorbol myristate acetate) or stimulate chemotaxis (F-Met-Leu-Phe) increased deformability. On the contrary, PAM deformability was not changed by phagocytosis of Staphylococcus aureus or latex beads. Pharmacologic agents that alter PAM adhesion (aspirin, indomethacin, physiologic dose hydrocortisone) or inhibit glycolysis (2-deoxyglucose) had no influence on filtration deformability. Filtration PAM deformability reflects passive whole cell rigidity, which appears to be determined by the state of polymerization of the actin-myosin microfilament complex.

Animals↗
PubMed1982

Allogeneic bone marrow transplantation in acute nonlymphocytic leukemia: a pilot study.

The objective of the current study, initiated in 1976, was to improve upon the high relapse rate and subsequent mortality in children and young adults with acute nonlymphocytic leukemia (ANLL). Seventeen patients, ages 6--28, with ANLL in first bone marrow remission, received cyclophosphamide and total body irradiation using a radiation scheme of 750 rad (7.5 Gy) total dose, delivered at a dose rate of 26 rad (26 cGy) per minute. Allogeneic marrow from HLA-matched sibling donors was followed by prophylactic therapy or graft-versus-host disease (GVHD). Median follow-up of the entire group is 20+ mo; survivors have been followed for a minimum of 14+ mo. Interstitial pneumonitis was observed in 6% of patients, and GVHD was observed in 29%. Seventy percent of patients are alive and in complete continuous remission. Two patients have relapsed (at 7 and 24 mo). Actuarial relapse-free survival is 76% at 1 yr and 64% at 5 yr. Quality of life in this disease-free survivors is excellent; all patients are free of active GVHD, receive no maintenance chemotherapy, and have high Karnofsky performances scores. High dose rate total body irradiation plus cyclophosphamide followed by allogeneic BMT may provide an opportunity for long-term complication-free survival in a substantial proportion of children and young adults with ANLL.

Acute Disease↗
PubMed1982

The irreversibly sickled cell.

The characteristics of irreversibly sickled cells (ISC) are reviewed in relationship to their potential significance in the initiation of sickle cell vaso-occlusion. Although ISC are implicated in the shortened red cell survival of sickle cell anemia, there is no direct correlation to the frequency or severity of sickle crisis. ISC are heterogeneous in their physical properties suggesting the possibility that a subpopulation may be disproportionately important in causing vaso-occlusion. Study of their deformability heterogeneity of ISC showed that filtration-separated hard ISC are similar in morphology and intracellular composition to soft ISC, and would not be distinguished on blood smear.

Anemia, Sickle Cell↗
PubMed1981

Immune thrombocytopenia in severe neonatal infections.

Thrombocytopenia occurs frequently in newborn infants with sepsis, but the exact mechanism remains obscure in those infants who do not have evidence of disseminated intravascular coagulation. Since recent work has suggested a possible immune mechanism for thrombocytopenia observed in adults with sepsis, we have investigated the role of platelet-associated immunoglobulin in severe neonatal infections. To detect PAIgG we use a method employing protein A and peroxidase-antiperoxidase as a labeled antibody. PAIgG was quantitated by phase contrast microscopy and expressed as a reactive index. Our control group included 16 normal newborn infants whose mean RI was 0.65 +/- 0.01 SE. In addition to the control group, five infants with nonimmune thrombocytopenia were included; their mean RI was 0.66 +/- 0.01 SE. Seventeen newborn infants with severe infections were assayed for PAIgG. Eight of nine infants with bacterial infections had increased RI, with a mean of 1.16 +/- 0.03 SE (P less than 0.01). Six of the eight infants with viral infections had elevated RI, with a mean of 1.23 +/- 0.03 SE (P less than 0.01). These findings suggest that an immune mechanism may be involved in the thrombocytopenia of severe neonatal infection.

Bacterial Infections↗
PubMed1981

'Pseudolymphoma'. A case associated with primary immunodeficiency disease and polyglandular failure syndrome.

An atypical lymphoproliferative process occurred in the liver and spleen of a child with combined immunodeficiency disease and polyglandular failure syndrome. The initial pathologic interpretation was that of malignant lymphoma, although the child's subsequent clinical course was complicated by rheumatoid arthritis, thyroiditis, and chronic active hepatitis, with no clear evidence of lymphoid neoplasia. This case illustrates that unusual lymphoid proliferations in patients with immunodeficiencies may simulate malignant lymphoma.

Adolescent↗
PubMed1981

Comparison of vincristine utilized simultaneously or 24 hours before cyclophosphamide in maintenance regimen of acute lymphoblastic leukemia of children: a report of Childrens Cancer Study Group.

A controlled clinical study in children with lymphoblastic leukemia was conducted to measure the potential benefit of time sequencing vincristine and cyclophosphamide. Vincristine and cyclophosphamide were utilized in a maintenance regimen in children after a remission had been obtained. Patients received vincristine either 24 hours before cyclophosphamide or simultaneously with cyclophosphamide. The median time to relapse and the number of continued remissions was significantly increased for patients receiving vincristine 24 hours before cyclophosphamide when compared to those patients receiving both drugs simultaneously. The results of this comparative study indicate that the sequential use of vincristine and cyclophosphamide for maintenance of a second relapse in childhood ALL produces a greater duration of remission than when both are used simultaneously.

Adolescent↗
PubMed1981

Aplastic anemia associated with the Shwachman syndrome. In vivo and in vitro observations.

Two patients are described with constitutional hematologic abnormalities associated with pancreatic exocrine deficiency (the Shwachman syndrome). These patients, however, exhibited many features similar to other constitutional hematologic disease, such as Fanconi's anemia, which are atypical for Shwachman syndrome. These features include severe pancytopenia, markedly decreased colony forming units in culture (CFU-C), a response to corticosteroids, and leukemic transformation. A suppressor mechanism could not be demonstrated as the cause of the severe pancytopenia, based on in vitro bone marrow co-culture experiments. These patients demonstrate the extreme clinical severity which can be seen in the Shwachman syndrome, as well as the gamut of shared characteristics among the various syndromes associated with constitutional hematologic aberrations.

Anemia, Aplastic↗
PubMed1980

Thrombotic and hemorrhagic strokes complicating early therapy for childhood acute lymphoblastic leukemia.

Sudden cerebrovascular insults occurred during or immediately following remission induction therapy in 4 children with acute lymphoblastic leukemia. In 3, cerebral infarction was due to thrombosis. In the fourth, an intracerebral hematoma developed representing either frank hemorrhaging or a hemorrhagic infarction. None of the patients had central nervous system leukemia or extreme leukocytosis at the time of diagnosis. Symptoms were obtundation, hemiparesis, seizures, and headache. The induction chemotherapy included L-asparaginase which causes deficiencies of antithrombin, plasminogen, fibrinogen, and factors IX and XI. These hemostatic abnormalities may explain the thromboses and bleeding observed in these children.

Adolescent↗
PubMed1980

Successful bone-marrow transplantation for infantile malignant osteopetrosis.

A five-month-old girl with autosomal-recessive osteopetrosis received a bone-marrow transplant from her five-year-old HLA-MLC-identical brother after preparation with cyclophosphamide and modified total-body irradiation. Engraftment was documented by chromosomal analysis. Anemia, thrombocytopenia, and leukoerythroblastosis corrected within 12 weeks of transplantation. Low serum calcium and elevated serum alkaline and acid phosphatase levels became normal. Serial x-ray studies revealed bony remodeling and new nonsclerotic bone formation. A pretransplantation bone biopsy revealed small marrow spaces, rare marrow elements, increased osteoclasts, and no bony resorption. After transplantation, osteoclasts were actively resorbing bone, and medullary cavities contained normal bone marrow. Fluorescent Y-body analysis after transplantation revealed donor (male) osteoclasts and recipient (female) osteoblasts. Monocyte bactericidal activity, markedly decreased before transplantation, became normal. Vision, hearing, growth, and development were progressively improving 16 months after transplantation. Allogeneic bone-marrow transplantation appears to be the treatment of choice in this fatal disorder.

Blood Bactericidal Activity↗
PubMed1980

Detection of platelet associated IgG in immune thrombocytopenia: a new assay employing protein A and peroxidase anti-peroxidase (PROA-PAP).

Immune thrombocytopenia is frequently encountered in medical practice and is generally accepted as being caused by an IgG antibody. The capability of detecting platelet-bound IgG as a diagnostic and therapeutic modality is critical for appropriate care and management of patients with idiopathic thrombocytopenic purpura (ITP), as well as other immune thrombocytopenias. We have modified our previous assay (Br J Haematol 37:265, 1977) by employing protein A and PAP as a labeled antibody. Surface bound platelet IgG was quantitated by phase contrast microscopy after incubation with PAP, graded per 100 platelets and expressed as a reactive index (RI). Controls (n=13) had RIs ranging from 0.49 to 0.72 (mean 0.63 +/- 0.02 SE). The nonimmune thrombocytopenic group (n=7) had an RI ranging from 0.58 to 0.72 (mean 0.64 +/- 0.01 SE). In contrast, the immune thrombocytopenic group (n=28) had RIs ranging from 1.04 to 1.75 (mean 1.43 +/- ;0.03 SE). Platelet-associated IgG was evaluated further by absorbing representative sera samples from each group against washed granulocytes, red cells and platelets. Only when sera from the immune thrombocytopenic group were absorbed against platelets did the reactive indices of pre- and postabsorption samples change significantly. These findings suggest that our assay is clinically applicable in detecting platelet-associated IgG in immune thrombocytopenia and has the advantage of being rapid, reproducible and easy to perform in a clinical laboratory.

Adolescent↗
PubMed1980

Fatal veno-occlusive disease of the liver following high dose chemotherapy, irradiation and bone marrow transplantation.

In two patients fatal veno-occlusive disease of the liver developed after bone marrow transplantation for underlying malignancies. Both had received significant pretransplant chemotherapy, including cystosine arabinoside, and total body irradiation. The diagnosis of veno-occlusive disease should be considered in patients in whom hepatomegaly, ascites and deteriorating liver function tests develop after they have received cancer chemotherapy.

Antineoplastic Agents↗
PubMed1980

The Wiskott-Aldrich syndrome in the United States and Canada (1892-1979).

Information was collected on 301 cases of the Wiskott-Aldrich syndrome in the United States and Canada Examination of available medical records, death certificates and published case reports on these patients showed that they came from a wide geographic area and many diverse ethnic and racial groups. No significant difference was found in the incidence of cases born between 1947 and 1976; the overall rate was 4.0 per million live male births in the United States. Median survival has increased with time from eight months for patients born before 1935 to 6.5 years for those born after 1964. Seventy-six of the 301 patients (25%) were still alive at last follow-up and ranged in age from 1 to 36 years with a median of 10 years. Causes of death were primarily limited to infections or bleeding, but malignancy represented a significant problem. Twelve percent of the group (36 of 301) developed malignancy, the predominant types being lymphorecticular tumors (23 of 36) and leukemia (7 of 36). The overall relative risk for malignancy was found to be greater than 100 times that of the general population and was found to increase with increasing age.

Adolescent↗
PubMed1980

Selective deficiency in collagen-induced platelet aggregation during L-asparaginase therapy.

Platelet aggregation studies were performed on 10 pediatric patients with acute lymphoblastic leukemia (ALL) receiving induction therapy with vincristine, prednisone, and L-asparaginase. An isolated abnormality in platelet aggregation in response to collagen was found in all patients during the course of therapy. Platelet aggregation in response to collagen normalized following the discontinuation of L-asparaginase, while patients were still on vincristine and prednisone. In contrast to the abnormal collagen response, platelet aggregation induced by epinephrine, arachidonic acid, adenosine diphosphate (ADP), and thrombin were normal both during and following therapy. In the one patient with a normal platelet count before therapy, aggregation induced by all agents was normal. This selective abnormality in collagen aggregation therefore appears to result from therapy, with the use of L-asparaginase in particular being implicated.

Asparaginase↗