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Biomedical subjects

L A Solberg

Publications and source records attributed to L A Solberg.

At least 19 recordsLinked to original sources
PubMed1997

New drugs in essential thrombocythemia and polycythemia vera.

Among the chronic myeloproliferative disorders, polycythemia vera and essential thrombocythemia are unique because of their association with thrombohemorrhagic manifestations and their relatively indolent clinical course. Patients with essential thrombocythemia may not have a significant shortening of life-expectancy and most may not require specific therapy. However, patients with polycythemia vera have a significant risk of transformation of polycythemia vera into acute leukemia or postpolycythemic myelofibrosis (or both). 'High-risk-for-thrombosis' patients with either polycythemia vera or essential thrombocythemia require specific therapy with a platelet-lowering agent to prevent thrombotic complications. Currently, the standard agent used for this is hydroxyurea. However, its tetratogenic and leukemogenic potential has been of concern. As a result, new platelet-lowering agents are being evaluated in the treatment of polycythemia vera and essential thrombocythemia. Anagrelide and interferon alfa are two such agents and have been shown to be effective in reducing platelet counts in patients with chronic myeloproliferative disorders. The putative mechanism of action of these drugs, their specific activity in polycythemia vera and essential thrombocythemia, side-effect profile, and current indications are discussed herein.

Antineoplastic Agents↗
PubMed1995

Continuous infusion etoposide/carboplatin for treatment of refractory acute leukemia.

Etoposide (125 mg/m2/d) and carboplatin (200 mg/m2/d) were administered by continuous 5-day intravenous infusion to 10 patients with relapsed or refractory acute leukemia (7 ANLL, 1 ALL, 2 blast crisis of CGL). No complete or partial response was observed despite dose-limiting toxicity characterized by severe diarrhea in four patients and neutropenic colitis in two additional cases. We cannot recommend the present schedule of drug administration for the treatment of acute leukemia.

Adolescent↗
PubMed1995

Refractory and relapsing multiple myeloma treated by blood stem cell transplantation.

Between June 1989 and June 1992, 12 patients with advanced multiple myeloma underwent peripheral blood stem cell autotransplantation after high-dose chemotherapy and radiotherapy. The conditioning regimen included melphalan (140 mg/m2), high-dose cyclophosphamide (120 mg/kg), methylprednisolone (2 g daily x 7), and total body irradiation (9-12 Gy). Transplant morbidity included severe mucositis (n = 7) and acute renal failure (n = 2) related to infusion of the stem cells. Engraftment was delayed (n = 4) in this heavily pretreated population, and two patients had complete graft failure. Despite the advanced nature and chemotherapy-refractory state of their disease, 11 of 11 evaluable patients achieved an objective response. Six patients survived to leave the hospital, and four remain alive--one died of acute leukemia induced by prior melphalan exposure. Three of the four are relapse-free at a median of 24.9 months (range, 18-28 months). Some patients with advanced refractory multiple myeloma can achieve objective responses from highdose chemoradiotherapy with peripheral blood stem cell rescue. Harvesting peripheral blood stem cells from high-risk patients early in their disease for later use may decrease the risk of graft failure. Peripheral blood stem cell transplantation after high-dose chemotherapy and total body irradiation can produce durable responses in patients with advanced refractory myeloma.

Acute Kidney Injury↗
PubMed1994

Rates of regression and progression of dysplastic lesions in the nasal mucosa in nickel workers: a Markov model approach.

Nasal epithelial dysplasia is considered a precancerous state. From 1976 through 1989, regular screening for such lesions has been performed among workers at the Falconbridge nickel refinery in Kristiansand. The longitudinal data thus obtained have been evaluated to ascertain to what extent, if any, pre-existing dysplasia can regress when exposure to nickel is reduced. A total of 418 pairs of observations were available from 243 workers. Interpretation of the data is complicated by the fact that dysplasia may remain undetected in small biopsies and the probability of detection of existing dysplasia was, therefore, incorporated into the two-state Markov model. Transition probability rates were estimated by maximum likelihood. The results suggest that regression of dysplasia has taken place and that regression rates increased with time. This finding probably reflects a decreased exposure resulting from a combination of a reduction in airborne nickel, improved personal hygiene and allocation of workers with dysplasia to work in areas with lower nickel exposure. Our results indicate that the chance of developing carcinomas related to nickel exposure is reduced. There are, however, indications that dysplasias continue to develop at a low rate.

Humans↗
PubMed1994

Acute porphyrias: diagnosis and management.

To summarize recent information about acute porphyrias and to provide clinicians with a practical diagnostic and management approach, we reviewed the pertinent literature and our clinical experience. The acute porphyrias are characterized by recurrent attacks of abdominal pain with or without additional manifestations of autonomic dysfunction or neuropsychiatric symptoms. On the basis of the potential of these disorders to affect the skin, they are further subdivided into neuroporphyrias and neurocutaneous porphyrias. During acute attacks, acute porphyria is always associated with increased levels of urinary porphyrin precursors. Between attacks, patients with neurocutaneous porphyrias may have normal urinary porphyrins; therefore, stool porphyrins, which are invariably increased, are the most helpful. Latent disease can be detected by the measurement of either urinary and stool porphyrins or cellular enzyme activity. Specific intravenous therapy with hematin has resulted in biochemical remissions, but its clinical benefit remains controversial. Measurement of urinary and stool porphyrins or porphyrin precursors is critical for the diagnosis of clinically overt acute porphyria. Enzyme assays are helpful in supporting the diagnosis but are best used to identify family members with latent disease. Preventive measures and supportive therapy are the mainstays of current management of patients with porphyria.

Acute Disease↗
PubMed1994

Bone marrow aspirate immunofluorescent and bone marrow biopsy immunoperoxidase staining of plasma cells in histologically occult plasma cell proliferative marrow disorders.

Immunofluorescent staining (immunofluorescence bone marrow aspirate) and immunoperoxidase staining (immunoperoxidase bone marrow biopsy) were compared in 26 patients with plasma cell dyscrasia and less than 10% marrow plasma cells. Their clinical diagnoses included monoclonal gammopathy of undetermined significance (13 patients), treated multiple myeloma (four patients), multiple myeloma with less than 10% marrow plasma cells (two patients), primary systemic amyloidosis (two patients), monoclonal gammopathy of undetermined significance with neuropathy (two patients), angiofollicular lymph node hyperplasia (two patients, all with the POEMS [polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, and skin changes] syndrome), and primary (amyloidosis) amyloid neuropathy (one patient). The percentage of plasma cells was greater than 5% in 23% of patients and less than or equal to 5% in 77% of patients. With immunofluorescence bone marrow aspirate and immunoperoxidase bone marrow biopsy, light-chain restriction was demonstrated in 84% of all cases and accurately determined in 96% of all cases as shown by serum and urine paraprotein analysis or tissue amyloid typing. Monoclonal populations of plasma cells can be readily identified with immunofluorescence bone marrow aspirate and immunoperoxidase bone marrow biopsy in most patients with paraproteins and marrow plasmacytoses not diagnostic of multiple myeloma.

Adult↗
PubMed1993

[Malacoplakia in the endometrium. A rare cause of postmenopausal bleeding].

Malacoplakia of the endometrium and the rest of the female genital tract is rare. The condition is usually postmenopausal, and an important clinical finding is vaginal bleeding. Clinically, what is actually malacoplakia is often suspected to be a malignant disease. Pathologically, however, malacoplakia is easily distinguishable from carcinoma, owing to the typical, light colour of the swear when examined under the microscope, showing. Histiocytes with abundant eosinophilic granular cytoplasm and varying degrees of intracellular and extracellular Michaelis-Gutman bodies. As far as we know, we describe the first case in Norway of postmenopausal bleeding in a 78 year old woman, caused by malacoplakia of the endometrium.

Aged↗
PubMed1992

Myelodysplastic syndromes. Pathogenesis, diagnosis and treatment.

Our understanding of the biology of leukemia and myelodysplasia is still only partial. The diagnosis of myelodysplasia is often based on quantitative and qualitative findings in the peripheral blood and bone marrow. These findings are often shared by other disorders. There is a need for sensitive and inexpensive laboratory tests to determine clonality and karyotypic abnormalities in this disorder. Future classifications of these syndromes will need to be based on morphologic and biologic markers that are closely linked to disease progression, response to treatment, and survival. Our limited understanding of the pathogenesis of MDS decreases the specificity and effectiveness of our therapeutic interventions. Agents that are minimally toxic such as CRA, danazol, 1,25-dihydroxyvitamin D3, androgens, and pyridoxine are seldom useful. Antileukemic therapy and allogeneic bone marrow transplantation have a major role to play in patients younger than 45 years of age; in older patients these treatment modalities remain controversial because of their toxicity. Hematopoietic growth factors, used alone or in combination, may improve the quality of life and improve survival of patients with MDS. Growth factors may also decrease treatment-related mortality associated with chemotherapy and bone marrow transplantation and render these treatment modalities available for a higher percentage of patients. The development of more specific differentiating agents may permit hematopoietic differentiation while minimizing side effects.

Antineoplastic Agents↗
PubMed1992

Mayo Clinic experience with allogeneic and syngeneic bone marrow transplantation, 1982 through 1990.

Between April 1982 and July 1990, 101 patients underwent allogeneic or syngeneic bone marrow transplantation at the Mayo Clinic. This patient population consisted of 30 with acute nonlymphocytic leukemia, 25 with acute lymphoblastic leukemia, 29 with chronic granulocytic leukemia, and 17 with other diseases (aplastic anemia in 7, myelodysplastic syndrome in 5, and lymphoma in 5). The results achieved in our patients who underwent transplantation in first complete remission of both acute nonlymphocytic leukemia and acute lymphoblastic leukemia compare favorably with previously reported results. Only 1 of 15 patients (7%) with acute nonlymphocytic leukemia and 2 of 8 patients (25%) with acute lymphoblastic leukemia who underwent transplantation in first complete remission had a relapse. Thus, we recommend early bone marrow transplantation during initial complete remission for patients with either of these disorders who have adverse prognostic factors. In contrast, of 12 patients with either acute nonlymphocytic leukemia or acute lymphoblastic leukemia who underwent transplantation during relapse, 11 died within 6 months. Therefore, such patients should be offered new experimental treatments. Our patients with chronic granulocytic leukemia fared better when they underwent transplantation early during the course of their disease rather than during the accelerated or blast phase. Prospective studies are needed to determine the best approach in these patients.

Academic Medical Centers↗
PubMed1992

Congenital heart defects, hamartomas of the tongue and polysyndactyly in a sister and brother.

We report a sister and brother with congenital heart defects, hamartomas of the tongue and polydactyly. Both had coarctation of the aorta, which was repaired in early infancy. In addition, the girl had atrioventricular canal. She died postoperatively at age 4 years. The boy had subaortic stenosis and died of pneumonia at age 2 years. Both children had normal psychomotor development. The parents were healthy and unrelated. The familial occurrence could be due to a previously unrecognized autosomal recessive syndrome or parental gonadal mosaicism for a dominant syndrome.

Abnormalities, Multiple↗
PubMed1992

Post-irradiation somnolence syndrome in an adult patient following allogeneic bone marrow transplantation.

Neurologic disturbances are common following the intensive chemotherapy and radiotherapy of bone marrow transplantation (BMT) conditioning regimens. The somnolence syndrome, which occurs in most children treated for leukemia with prophylactic cranial irradiation, has previously not been reported following BMT. This syndrome consists of transient lethargy, irritability, headaches, low grade fevers, gastrointestinal disturbances and depression. We report the case of a 38-year-old female with acute non-lymphocytic leukemia who developed symptoms typical of the somnolence syndrome 8 weeks following 1320 cGy total body irradiation and cyclophosphamide conditioning. Encephalographic findings were consistent with the syndrome, and no additional infectious or metabolic disorders could be identified. As predicted by the pediatric experience, the symptoms were transient, resolving following steroid and anti-depressant therapy. Among patients undergoing radiation based conditioning regimens, especially those not receiving concurrent steroid therapy, the appearance of post-transplantation somnolence may be an expression of this syndrome.

Adult↗
PubMed1991

Prognostic significance of computed tomography of the brain in thrombotic thrombocytopenic purpura.

We studied the prognostic value of computed tomography (CT) of the brain for neurologic morbidity in patients with thrombotic thrombocytopenic purpura. On review of Mayo Clinic records for 1975 through 1985, we found 32 patients with thrombotic thrombocytopenic purpura, 20 of whom had undergone CT of the brain during their hospitalization. Despite major neurologic symptoms and signs, normal CT findings were associated with complete neurologic recovery. Seventy percent of patients with normal results of CT of the brain recovered and had no neurologic deficits, whereas 80% of patients with CT abnormalities died or had permanent neurologic sequelae. A review of the literature supports these conclusions. Thus, we suggest that CT of the brain be done in any patient with thrombotic thrombocytopenic purpura and neurologic deficits. Regardless of the severity of neurologic involvement, normal CT findings should encourage continued vigorous treatment of the patient because a normal scan supports the possibility of full clinical recovery.

Adolescent↗
PubMed1990

Clonal studies in the myelodysplastic syndrome using X-linked restriction fragment length polymorphisms.

We used the X-linked restriction fragment length polymorphism (RFLP)-methylation strategy to study the clonal basis of the myelodysplastic syndrome (MDS) in seven patients. RFLP-methylation analysis was performed on cell populations from bone marrow (BM) aspirates and peripheral blood using probes specific for the hypoxanthine phosphoribosyltransferase (HPRT) or phosphoglycerate kinase (PGK) gene regions. Density gradient centrifugation methods were used to separate granulocytes and monocytes, and T lymphocytes were positively selected by CD2 (a pan-T marker) immunoconjugated magnetic beads. Cell populations from BM aspirates in 6 of the 7 patients with MDS showed a monoclonal pattern of X-inactivation. The neutrophilic and T-lymphocytic cell fractions were analyzed in 4 of the 6 patients, and the monocytic cell fraction in one of these, and all fractions analyzed showed a similar monoclonal pattern. In 2 of the latter 4 patients, both of whom had normal karyotypes, DNA from a skin biopsy showed a polyclonal pattern. Our data suggest that MDS is a clonal disorder, even in the absence of detectable cytogenetic abnormalities, and that the abnormal clone is capable of myeloid, monocytic, and lymphoid differentiation.

Bone Marrow↗
PubMed1990

A biological and computational model of megakaryocyte development as a stochastic branching process.

The purpose of this paper is to describe a model of megakaryocytopoiesis as a branching process with stochastic processes regulating critical control points of differentiation along the stem cell megakaryocyte platelet axis. Progress of cells through these critical control points are regulated by transitional probabilities, which in turn are regulated by influences such as growth factors. The critical control points include transition of resting megakaryocytic stem cells (CFU-meg) into proliferating stem cells, the cessation of cytokinesis, and the cessation of DNA synthesis. A computerized computational method has been developed for directly fitting the stochastic branching model to colony growth data. The computational model has allowed transitional probabilities to be derived from colony size data. The model provides a unifying explanation for much of the heterogeneity of stages of maturation within populations of megakaryocytes and is fully compatible with historical data supporting the stochastic nature of hematopoietic stem cell regulation and with modern molecular concepts about control of the cell cycle.

Cell Differentiation↗
PubMed1990

A new murine monoclonal antibody for the diagnosis of erythroleukemia.

The authors have developed a murine monoclonal antibody, RC-82.4, against an antigen expressed by a human erythroleukemia cell line OCI-MIR. The antibody reacts with an antigen expressed by proerythroblasts, normoblasts, and some reticulocytes but not expressed in erythrocytes, granulocytes, monocytes, megakaryocytes, plasma cells, or lymphocytes. The authors have established an immunocytochemical method for studying bone marrow smears with RC-82.4. By studying bone marrow smears from 11 patients with M-6 erythroleukemia and 104 patients with various other hematologic and nonhematologic malignancies, the authors have found that RC-82.4 has great sensitivity and specificity in recognizing erythroid differentiation in blasts. The authors have used RC-82.4 and antihemoglobin antibodies to identify erythroblasts in acute and secondary acquired cases of erythroleukemia that would have been unclassifiable by morphologic and all other conventional cytochemical and immunocytochemical criteria.

Adult↗
PubMed1989

Adult-onset cyclic bicytopenia: a case report and review of treatment of cyclic hematopoiesis.

A unique case of adult-onset synchronous cyclic neutropenia and thrombocytopenia occurring at six-week intervals is presented. Periods of cytopenia were associated with fever, myalgias, gastrointestinal symptoms, and mild mucocutaneous bleeding. Alternate-day steroid treatment failed to correct the periodic fluctuations in peripheral blood counts but ameliorated symptoms during cytopenia. The treatment of cyclic hematopoiesis is reviewed.

Agranulocytosis↗
PubMed1989

Acute leukemia with abnormal thrombopoiesis and inversions of chromosome 3.

Abnormal thrombopoiesis has been described in acute leukemias associated with inv(3) (q21q26.2) or t(3;3)(q21;q26.2). We reviewed 13 patients seen at the Mayo Clinic since 1979 with inversions of chromosome 3 or related abnormalities; 12 acquired and one constitutional. The patient with the constitutional abnormality had an inv(3)(p21q29) and mild leukocytosis and thrombocytosis. Among the 12 patients with acquired abnormalities, five had inv(3) (q21q26.2), three had t(3;3)(q21;q26.2), one had del(3)(q12q21), one had ins(6;3) (p21;q21q26.2), one had inv(3)(p21q12), and one had r(3)(p?21q?21). Each of these patients developed acute leukemia; eight had antecedent myelodysplastic syndrome, eight presented with platelet counts greater than 100 x 10(3)/microliters, and six had atypical megakaryocytic hyperplasia. Five patients had ringed sideroblasts in their marrow, an antecedent refractory anemia with ringed sideroblasts, or erythroleukemia. Seven patients received chemotherapy but showed no response. From the time of chromosome study, the median duration of survival was 4 months. Our results suggest that 1) although abnormal megakaryocytopoiesis is observed in patients with inv(3)(q21q26.2), multiple hematopoietic lineages are also involved in the neoplastic process; 2) an antecedent myelodysplastic syndrome is common in acute leukemia with inv(3) or related abnormalities; 3) affected patients have a poor survival and are resistant to conventional chemotherapy; and 4) abnormal megakaryocytopoiesis in acute leukemia may also be associated with pericentric inversions of chromosome 3.

Acute Disease↗