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Biomedical subjects

Fredrik Celsing

Publications and source records attributed to Fredrik Celsing.

10 recordsLinked to original sources

Altered expression of key cellular gene products accompanies development of resistance to nitric oxide.

NALM-6 is a pre-B leukemia cell line sensitive to exogenous nitric oxide (NO), which enters into apoptosis during 24 h of exposure to low doses of the NO donors SNAP (100 microM) or DETA-NO (250 microM). By culturing NALM-6 with repeated and increasing concentrations of SNAP, we obtained a variant (NALM-6R) that retains >95% viability and does not enter into apoptosis during 24 h culture in the presence of up to 500 microM SNAP or 750 microM DETA-NO. A power blot screen performed with 277 antibodies on cell lysates from NALM-6 and NALM-6R cultured without NO donors served to determine the altered constitutive expression of 19 proteins in NALM-6R. Proteins affected in the less sensitive cell line NALM6-R are involved in the regulation of apoptosis, the cell cycle, cell interactions, signal transduction, cell morphology, and cell motility. This model shows that repeated exposure of tumor cells to NO may either select NO-resistant cells or contribute to NO-sensitive conversion into NO-resistant cells. The identification of the proteins that are affected during this transition may help us to define the mechanisms that are involved in cell resistance to NO-cytotoxicity which often accompany clinical progression.

Apoptosis↗

Alemtuzumab therapy for severe autoimmune hemolysis in a patient with B-cell chronic lymphocytic leukemia.

B-cell chronic lymphocytic leukemia (B-CLL) is the most common cause of autoimmune hemolytic anemia (AIHA), and a subgroup of these patients who develop both these conditions fail to respond to corticosteroids, cytotoxic drugs, splenectomy, and iv immunoglobulins. Alemtuzumab is a humanized anti-CD52 monoclonal antibody that is an effective therapy for B-CLL, mycosis fungoides, and T-cell prolymphocytic leukemia. Here we present a case report of a 78-yr-old woman with B-CLL and progressive life-threatening AIHA with hemoglobin count 5.5 g/dL following fludarabine treatment, who was treated successfully with alemtuzumab. The anemia was completely reversed and hemoglobin count remains at 14 g/dL after 15 mo of unmaintained follow-up. No infectious complications were noted during or after alemtuzumab therapy. We conclude that alemtuzumab may be indicated for the treatment of AIHA in B-CLL patients who have failed other treatments.

Aged↗

High expression of bfl-1 contributes to the apoptosis resistant phenotype in B-cell chronic lymphocytic leukemia.

In order to identify regulatory genes involved in the development of an apoptosis-resistant phenotype in patients with chemotherapy refractory B-cell chronic lymphocytic leukemia (B-CLL) expression of apoptosis-regulating genes in B-CLL cells was quantified using cDNA arrays and RT-PCR. Data were obtained from and compared between 2 groups of B-CLL patients with either nonprogressive, indolent, previously untreated disease and with leukemic cells sensitive to in vitro fludarabine-induced apoptosis, referred to as sensitive B-CLL (sB-CLL) or with progressive, chemotherapy refractory disease and with leukemic cells resistant to in vitro fludarabine-induced apoptosis, referred to as resistant B-CLL (rB-CLL). By performing a supervised clustering of genes that most strongly discriminated between rB-CLL vs. sB-CLL a small group of genes was identified, where bfl-1 was the strongest discriminating gene (p < 0.05), with higher expression in rB-CLL. A group of apoptosis-regulating genes were modulated during induction of apoptosis by serum deprivation in vitro in a similar manner in all cases studied. However, bfl-1 was preferentially downregulated in sB-CLL as compared to rB-CLL (p < 0.05). We conclude that bfl-1 may be an important regulator of B-CLL apoptosis, which could contribute to disease progression and resistance to chemotherapy, and as such represent a future potential therapeutic target.

Aged↗

FDG uptake in a catheter-related thrombus simulating relapse of lymphoma.

FDG-PET imaging was performed because of suspected recurrence of lymphoma of the chest. There was an area of increased activity posterior to the left sternoclavicular joint, suspected of being a relapse. Workup showed a thrombus at the tip of a central venous line corresponding to the FDG uptake. This is explained by the inflammatory process involving and surrounding chronic thrombus. Focal activity in relation to the tip of a venous catheter is very likely to have a benign etiology. It is important to recognize this not to overdiagnose a malignancy. For a correct interpretation, it is necessary to know the patient's history and having access to current radiologic examinations.

Adolescent↗

Phase II study of cyclophosphamide, interferon-alpha and betamethasone (CIB) as induction therapy for patients 60-75 years of age with multiple myeloma stages II and III.

Cyclophosphamide, interferon-alpha and betamethasone are all effective agents for the treatment of multiple myeloma (MM) with different mechanisms of action. The clinical effect of a combination of cyclophosphamide 725 mg/m(2) i.v. days 1 and 3, interferon-alpha 7 x 10(6) IE/m(2) s.c./day, days 1-4 and betamethasone 30 mg orally days 1-4 (CIB) was studied in patients aged 60-75 years with previously untreated MM stages II and III. Granulocyte-macrophage colony-stimulating factor (GM-CSF) 5 microg/kg/day s.c. was administered to all patients from day 5 until the day the granulocyte count exceeded 1.0 x 10(9)/l. CIB was repeated every fourth week. Interferon-alpha 3 x 10(6) IE s.c. t.i.w. was given as maintenance therapy in responding patients.A total of 28 patients (median age: 67 years) entered the study. In all, 12 patients had stage II and 16 had stage III MM. A total of 22 patients (79%) showed an objective response, including five complete remissions (CR) and 17 partial remissions (PR). All seven patients with Bence-Jones MM responded (five CR and two PR). The median response duration time was 14 months (range 5-38+). CIB was relatively well tolerated although febrile neutropenia or septicaemia occurred in 5% of the cycles and a dose-reduction of cyclophosphamide due to grade IV neutropenia was performed in 11% of the patients.CIB seems to be an effective regimen for remission induction in MM patients aged up to 75 years as an alternative to VAD (vincristine, doxorubicin, dexamethasone) if a regimen with intensity higher than that of oral melphalan/prednisone is warranted.

Aged↗

Phase II trial of subcutaneous anti-CD52 monoclonal antibody alemtuzumab (Campath-1H) as first-line treatment for patients with B-cell chronic lymphocytic leukemia (B-CLL).

This phase II study determined the efficacy and safety of alemtuzumab, a humanized anti-CD52 monoclonal antibody, delivered subcutaneously as first-line therapy, over a prolonged treatment period of 18 weeks in 41 patients with symptomatic B-cell chronic lymphocytic leukemia (B-CLL). Injections were administered subcutaneously 3 times per week, from week 2 to 3 onward. An overall response rate (OR) of 87% (95% CI, 76%-98%; complete remission [CR], 19%; partial remission [PR], 68%) was achieved in 38 evaluable patients (81% of intent-to-treat population). CLL cells were cleared from blood in 95% patients in a median time of 21 days. CR or nodular PR in the bone marrow was achieved in 66% of the patients and most patients achieved this after 18 weeks of treatment. An 87% OR (29% CR) was achieved in the lymph nodes. The median time to treatment failure has not yet been reached (18+ months; range, 8-44+ months). Transient injection site skin reactions were seen in 90% of patients. Rigor, rash, nausea, dyspnea, and hypotension were rare or absent. Transient grade IV neutropenia developed in 21% of the patients. Infections were rare, but 10% patients developed cytomegalovirus (CMV) reactivation. These patients rapidly responded to intravenous ganciclovir. One patient, allergic to cotrimoxazole prophylaxis, developed Pneumocystis carinii pneumonia. Alemtuzumab is highly effective as first-line treatment in patients with B-CLL. Prolonged treatment is important for maximal bone marrow response. Subcutaneous administration induced very few "first-dose" flulike symptoms and may reduce health care costs in comparison with the intravenous infusions.

Adult↗

Oral cladribine for B-cell chronic lymphocytic leukaemia: report of a phase II trial with a 3-d, 3-weekly schedule in untreated and pretreated patients, and a long-term follow-up of 126 previously untreated patients.

A phase II study was undertaken to evaluate the efficacy and toxicity of a new schedule of cladribine administration (10 mg/m2 orally daily for 3 d every 3 weeks) in 107 patients with B-cell chronic lymphocytic leukaemia (CLL). To minimize toxicity, treatment withdrawal criteria were defined. The results of the 63 previously untreated patients were retrospectively compared with 63 from an earlier study using a 5-d monthly schedule. The compiled data were analysed for prognostic factors for survival. No significant difference regarding response were seen in the two cohorts of the 126 previously untreated patients. The complete response (CR), nodular partial response (nPR) and partial response (PR) rates were 15%, 21% and 41%. Quality of response had no impact on survival. The 3- and 5-year overall survival for previously untreated patients was 73% and 58%, respectively, with a median follow-up of 54 months. Pretreatment haemoglobin <11.0 g/dl and elevated beta-2-microglobulin had a negative influence on survival. Major infections occurred in 21% of patients in the 3-d study compared with 35% in the 5-d study. The overall response (OR) and CR rates in the 40 previously treated patients were 34% and 5% respectively. Median overall survival was 24 months and median progression-free survival for responding patients was 14 months. Cladribine used as a single agent is an effective treatment with an acceptable safety profile for pretreated and untreated B-CLL. The achievement of complete remission was not a prerequisite for long-term survival.

Administration, Oral↗

Natural cytotoxicity to autologous antigen-pulsed dendritic cells in multiple myeloma.

To analyse autologous lymphocyte cytolytic activities of potential importance for cell-based immunotherapy in multiple myeloma (MM), in vitro differentiated dendritic cells (DCs) loaded with patient-specific monoclonal immunoglobulin (mIg) were used as autologous target cellsin cytotoxicity assays. Effector populations consisted of purified natural killer (NK) cells (CD56+, CD3-) and T cells (CD3+). The MM patients' NK cells cultured in the presence of interleukin 2 (IL-2) showed pronounced cytotoxic activity towards autologous mature DCs. Autologous MM DC targets displayed similar susceptibility to NK cell lysis, compared with allogeneic control DC targets, despite high surface expression of self major histocompatibility complex (MHC) antigens. However, some degree of classic MHC class I-mediated negative regulation was implicated in the NK-DC interactions, as indicated by class I blocking experiments. NK-mediated lysis was also discerned towards primary autologous MM cells. The results indicated that the major effector mechanism was mediated through the perforin-granzyme exocytosis pathway. In conclusion, NK cells from MM patients displayed significant and consistent cytotoxicity towards autologous mature DCs, suggesting that innate immunity could be implicated in MM and may influence the outcome of the administration of tumour antigen-pulsed DCs in treatment trials.

Calcium↗

[Immune defense is both stimulated and inhibited by physical activity].

Physical exercise may enhance some and depress other immune functions. The biological importance of these changes is not fully elucidated. Acute endurance exercise results in a relatively large redistribution of leukocytes between circulating blood and other tissues, as well as an increase in circulating cytokines. Some of these changes have been related to energy metabolism. A temporal correlation has been observed between altered immune functions and resistance to infections. A post-exercise infection can be either the result of a pre-exercise, sub-clinical infection amplified by the performed work or a novel infection, acquired during a period of decreased immune function shortly after exercise. Animal experiments have demonstrated that the susceptibility to infections after exercise depends on exercise intensity and duration, type of pathogen and time of inoculation. Exercise before inoculation with some bacterial agents can enhance resistance to infection, while exercise during an ongoing viral or bacterial infection worsens symptoms and enhances the risk for complications. Most studies demonstrate a deleterious effect of physical exercise in conjunction with infectious episodes.

Animals↗