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Biomedical subjects

B Ly

Publications and source records attributed to B Ly.

At least 19 recordsLinked to original sources
PubMed2002

Epidemiological profile of hemoglobinopathies in the Mauritanian population.

We performed a study of hemoglobin in 700 blood donors attending the Centre Hospitalier National de Nouakchott in Mauritania. We detected 116 cases of anomalies corresponding to a global prevalence of 16.6%. The analysis of the samples studied showed that 72.3 % of the donors were Blacks and 28.7 % were White Maurs ( Maures blancs). In the Black population the prevalence of hemoglobinopathies is 21.44% whereas among the White Maurs it is 4.47%. In this study, the six ethnic groups that constitute the Mauritanian population were also represented in the sample, but with different numbers. We noted some differences in the repartition of anomalies among these groups. The hemoglobin anomalies that were found are sickle cell anemia, beta-thalassemia, and delta-variant, all in heterozygous form. Geographical repartition revealed that the hemoglobin abnormalities are mostly encountered in the Southeast and the Southwestern parts of the country, which could be considered areas of high risk for hemoglobinopathies.

Blood Donors↗
PubMed2000

Role of the kinesin neck linker and catalytic core in microtubule-based motility.

Kinesin motor proteins execute a variety of intracellular microtubule-based transport functions [1]. Kinesin motor domains contain a catalytic core, which is conserved throughout the kinesin superfamily, followed by a neck region, which is conserved within subfamilies and has been implicated in controlling the direction of motion along a microtubule [2] [3]. Here, we have used mutational analysis to determine the functions of the catalytic core and the approximately 15 amino acid 'neck linker' (a sequence contained within the neck region) of human conventional kinesin. Replacement of the neck linker with a designed random coil resulted in a 200-500-fold decrease in microtubule velocity, although basal and microtubule-stimulated ATPase rates were within threefold of wild-type levels. The catalytic core of kinesin, without any additional kinesin sequence, displayed microtubule-stimulated ATPase activity, nucleotide-dependent microtubule binding, and very slow plus-end-directed motor activity. On the basis of these results, we propose that the catalytic core is sufficient for allosteric regulation of microtubule binding and ATPase activity and that the kinesin neck linker functions as a mechanical amplifier for motion. Given that the neck linker undergoes a nucleotide-dependent conformational change [4], this region might act in an analogous fashion to the myosin converter, which amplifies small conformational changes in the myosin catalytic core [5,6].

Adenosine Triphosphatases↗
PubMed1999

[Catheter-directed thrombolytic therapy--a current alternative to proximal deep venous thrombosis].

Deep venous thrombosis extending into the iliac veins is associated with significant acute and late morbidity despite adequate conventional treatment with heparin and oral anticoagulants. The purpose of this paper is to focus on a multidisciplinary, aggressive approach with catheter-directed thrombolysis, in which a catheter with many side-holes is placed within the thrombus and thrombolytics infused. The aim is to eliminate the thrombus, to provide unobstructed venous drainage from the affected limb, and to prevent recurrent thrombosis. Total recanalisation of the iliofemoral segment was achieved in three of four treated patients, while partial lysis was obtained in one patient with symptoms for four weeks. Two weeks after discharge, two patients had no symptoms, while two had a moderate leg oedema. All of the three women used oral contraceptives at the time of thrombus formation; two had hereditary thrombophilia. Most probably, successful catheter-directed thrombolysis will reduce the incidence of post-thrombotic syndrome, but there are no long-term follow-up studies after such treatment.

Adult↗
PubMed1999

[Chronic myeloid leukemia in health regions 1, 3, 4 and 5 during the period 1990-96].

The aim of the present investigation was to obtain information about treatment, clinical course and outcome for all patients with chronic myeloid leukaemia through a six-year period in a defined part of Norway. A total number of 141 patients fulfilled the diagnostic criteria. This is equivalent to 0.9 patients per 100,000 per year. The median age was 62 years. More than 70% of the patients were primarily treated with hydroxyurea, either alone or combined with interferon. 40 out of 57 patients younger than 55 years underwent allogeneic stem cell transplantation. Median survival for all patients was 36 months with an estimated five-year survival rate of 33%. Patients older than 55 years had a median survival of 30 months with 16% alive after five years. The five-year survival rate for patients younger than 55 years was 56%, for transplanted patients 72%. 60 of 84 patients older than 55 years have died after 4 1/2 years median observation time. Two thirds of those died of leukaemia; one third of other causes. 23 of 57 patients younger than 55 years have died. 11 of them had had transplantations and most of them died from transplantation-related causes, while leukaemia was the dominating cause of death in the others.

Adolescent↗
PubMed1999

[Empirical antibiotic treatment of patients with acute myelogenous leukemia].

All febrile episodes (a total of 276) which occurred in 85 patients with acute myelogenous leukaemia treated in four Norwegian centres during the period 1990-1994 were studied retrospectively in order to assess the efficacy of antibiotic treatment. 72% of these episodes were initially treated with benzyl penicillin and aminoglycoside (standard treatment), while alternative empirical treatment was given in the remaining cases. The treatment was successful in 94% of the febrile episodes initially treated with standard treatment and in 96% of the episodes which received alternative antibiotics. For both types of treatment, a change to second line antibiotic regimen was made for various reasons in a majority of cases. The combination benzyl penicillin and aminoglycoside seems to be a safe empirical treatment for febrile neutropenia in patients with acute myelogenous leukaemia in our treatment centres, provided that the treatment is modified in patients with unsatisfactory clinical response.

Adolescent↗
PubMed1998

[Chronic lymphatic leukemia. A population-based study of symptoms, findings, complications and choice of treatment].

224 patients with a recent diagnosis of chronic lymphocytic leukemia, confirmed by immune phenotype, were studied with a mean follow-up of 16 months. The median age was 72 years and the ratio of men to women was 1.51. An incidental diagnosis because of leukocytosis was made in 75% of the patients; in only 22% was the diagnosis related to symptoms. 80% were in stage A, 7.5% in stage B, and 12.5% in stage C. A relation was found between advanced stage and the number of lymphocytes in the blood, the percentage of lymphocytes in the bone marrow, WHO performance status, bacterial infection and disease-related mortality. Thus, six patients in stage C (21%) died because of infection (septicaemia or pneumonia), as opposed to only one out of 196 patients in stages A and B. The incidence of bacterial infection was 64% in stage C, as compared to 8.3% in stage A. Treatment with chlorambucil, started in 59 patients, was in accordance with the guidelines of the national programme for 52 of them. In contrast, a strict indication for prednisone (autoimmune cytopenia) was found in only 42% of 42 patients given this treatment.

Aged↗
PubMed1998

[Chronic lymphatic leukemia. Immunophenotyping as an aid to correct diagnosis].

The purpose of the study was to examine the validity of the primary diagnosis in chronic lymphocytic leukemia based on clinical and morphological criteria, and to examine the role of immune phenotyping for correct diagnosis in an unselected population-based group of patients. Over a 2-year period leukemic cells from 222 of 235 patients in Norway with a recent clinical diagnosis of chronic lymphocytic leukemia (CLL) were immune phenotyped in order to find cases erroneously diagnosed as CLL. Median age was 72.5 years, and the ratio of men to women was 1.47. At the time of diagnosis, 77% of the patients were in Binet stage A and 23% in stage B or C. Immune phenotyping, in some patients followed by lymph node or bone marrow biopsy, showed a different diagnosis in 11 (5%) of 222 patients: prolymphocytic leukemia, four patients (three B-cell and one T-cell); morbus Waldenstrøm, one patient; T-cell CLL, one patient; hairy cell leukemia, one patient; mycosis fungoides, one patient; mantle cell lymphoma, one patient; monocytoid B-cell lymphoma, one patient and immunoblastic lymphoma one patient. In eight of these 11 patients, the clinical features or morphology, or both, were atypical for CLL, but this was not recognized at the time of diagnosis. Thus, immune phenotyping is valuable for correct diagnosis in a small subgroup of patients with chronic B- or T-cell leukemia, and it is essential in patients with modest lymphocytosis (lymphocytes < 10. 10(9)/1).

Adult↗
PubMed1998

State of actin in gastric parietal cells.

Remodeling of the apical membrane-cytoskeleton has been suggested to occur when gastric parietal cells are stimulated to secrete HCl. The present experiments assayed the relative amounts of F-actin and G-actin in gastric glands and parietal cells, as well as the changes in the state of actin on stimulation. Glands and cells were treated with a Nonidet P-40 extraction buffer for separation into detergent-soluble (supernatant) and detergent-insoluble (pellet) pools. Two actin assays were used to quantitate actin the deoxyribonuclease I binding assay to measure G-actin and F-actin content in the two pools and a simple Western blot assay to quantitate the relative amount of actin in the pools. Functional secretory responsiveness was assayed by aminopyrine accumulation. About 5% of the total parietal cell protein is actin, with about 90% of the actin present as F-actin. Stimulation of acid secretion resulted in no measurable change in the relative amounts of G-actin and cytoskeletal F-actin. Treatment of gastric glands with cytochalasin D inhibited acid secretion and resulted in a decrease in F-actin and an increase in G-actin. No inhibition of parietal cell secretion was observed when phalloidin was used to stabilize actin filaments. These data are consistent with the hypothesis that microfilamentous actin is essential for membrane recruitment underlying parietal cell secretion. Although the experiments do not eliminate the importance of rapid exchange between G- and F-actin for the secretory process, the parietal cell maintains actin in a highly polymerized state, and no measurable changes in the steady-state ratio of G-actin to F-actin are associated with stimulation to secrete acid.

Actins↗
PubMed1997

Microtubule interaction site of the kinesin motor.

Kinesin and myosin are motor proteins that share a common structural core and bind to microtubules and actin filaments, respectively. While the actomyosin interface has been well studied, the location of the microtubule-binding site on kinesin has not been identified. Using alanine-scanning mutagenesis, we have found that microtubule-interacting kinesin residues are located in three loops that cluster in a patch on the motor surface. The critical residues are primarily positively charged, which is consistent with a primarily electrostatic interaction with the negatively charged tubulin molecule. The core of the microtubule-binding interface resides in a highly conserved loop and helix (L12/alpha5) that corresponds topologically to the major actin-binding domain of myosin. Thus, kinesin and myosin have developed distinct polymer-binding domains in a similar region with respect to their common catalytic cores.

Adenosine Triphosphatases↗
PubMed1997

Survival in 86 patients, aged 15-60, with primary acute myelogenous leukemia, treated with a common program in the Norwegian health regions I, III, IV and V in the period 1990-1995.

Eighty-six patients between 15 and 60 yr with primary acute myelogenous leukemia in health regions I, III, IV and V in Norway were treated according to a common protocol from 21 January 1990 until 1 September 1995 (until 1 January 1993 for health region IV). Seventy-one percent of the patients reached complete remission (CR) and went on to receive consolidation treatment. In addition to chemotherapy, 18 patients under the age of 52, i.e. 28% of all patients in this age group, received allogeneic bone marrow transplantation. A follow-up analysis was performed by 1 September 1996. The median overall survival was 15 months, estimated 3-yr survival 30% and estimated survival at 5 yr was 26%. The median duration of 1st CR was 19 months, and the leukemia-free survival at 3 yr was 29%. At follow-up 26/86 patients were alive, 18 in 1st CR (4 after BMT) and 8 in 2nd CR (5 after BMT in 2nd, 1 after BMT in early 1st relapse). These results are comparable to many previously published studies, but may be inferior to the results obtained with more intensive consolidation treatment, including high dose Ara C.

Adolescent↗
PubMed1996

[Local thrombolytic treatment of peripheral arterial thrombosis and embolism].

Local intra-arterial low-dose thrombolysis has become a therapeutic alternative for acute and subacute occlusion of vascular grafts and native vessels in the lower limbs. The series comprises 31 patients treated with Streptokinase as thrombolytic agent. Complete primary thrombolysis was achieved in 20 patients, whereas in 11 patients the outcome was only partially successful or a failure. Vascular stenoses were considered to precipitate thrombosis in 18 cases, and prompted percutaneous transluminal angioplasty after thrombolysis. Two-year patency was 48% (30-66%) in the total series and 74% (56-92%) among the patients with successful primary thrombolysis. There were no major complications. Five patients sustained local inguinal haemorrhage, of whom three required surgical revision. Local intra-arterial thrombolysis is an elaborate procedure associated with potential hazardous complications. It should be carried out in institutions with radiological and vascular surgical expertise.

Adult↗
PubMed1994

Childbirth and soul loss: the case of a Hmong woman.

The health of a Hmong woman had been deteriorating since she underwent caesarean section. She believes that her ill health is caused by her soul leaving her body during general anaesthesia. A caesarean was essential for the survival of the fetus, but it could have been better managed. The situation might have been prevented if the cultural beliefs and practices of the Hmong had been taken into account. Nevertheless, the agreement of the hospital to a soul calling ceremony in the operating theatre and the concerns expressed by hospital staff about her well-being are positive aspects, showing that mainstream health services can provide culturally sensitive care to consumers if they are informed of these cultural beliefs and practices.

Adult↗
PubMed1993

[Protein S deficiency, acute phase reaction and thrombosis].

Protein S deficiency increases risk of thrombosis. At present, we have information on 63 Norwegian individuals with hereditary protein S deficiency belonging to 25 different families. 42 of the individuals have experienced at least one thromboembolic episode, and seven a cerebral infarction before the age of 70 years. The amount of free protein S in plasma is dependent on variation of the acute phase protein C4b-binding protein (C4bBP). Acute phase response with increased C4bBP induces free protein S deficiency, and increases risk of thrombosis. In patients with protein S deficiency, warfarin may reduce free protein S to critically low levels, and thus explain why, in some patients, recurrent thrombosis occurs during warfarin treatment. In this situation, warfarin should be replaced by heparin.

Acute-Phase Proteins↗
PubMed1991

[Treatment of deep venous thrombosis with low molecular weight heparin (Fragmin)].

At our department, the routine treatment of deep venous thrombosis is low molecular weight heparin (Fragmin) in doses of 80-120 anti-Xa Units/Kg body weight/12h subcutaneously. In an open study we found that anti-thrombotic efficacy of the treatment, and safety with regard to bleeding, was the same as found in controlled studies. The patient population was characterized by old age and high morbidity. Nevertheless, eight out of 30 patients (26%) could be transferred to ambulant care on day 2-4. We conclude that low molecular weight heparin facilitates out-patient care of uncomplicated cases of deep venous thrombosis.

Adult↗
PubMed1991

Has the incidence of multiple myeloma in old age been underestimated? The myeloma project of health region I in Norway. I.

All patients in the region with newly discovered M components were registered from 15 Aug. 1984-31 Dec. 1986. Among a total of 393 patients enrolled, 162 had multiple myeloma (MM). The incidence rate was 6.6 per 100,000 population per year (age-adjusted to the European standard population), which is somewhat higher than previous reports based on hospital and autopsy records. In particular, the incidence rate was higher in the greater than 70 age group. Thus, the median age was 72 yr, which is the highest reported. As many as 71 (44%) of the 162 MM patients were asymptomatic; these asymptomatic patients had the same age distribution as the symptomatic ones. The stage distribution, occurrence of risk factors, response to chemotherapy, response duration and survival were similar in the age groups below and above the median and, in multivariate survival analysis, age was not an independent risk factor.

Adult↗
PubMed1990

A new case of total kininogen deficiency.

Six families with total kininogen deficiency have been described in the literature. We report herein an additional case in a Pakistanese woman. The defect was discovered accidentally due to lack of normal clot formation in a preoperative routine blood sample. She had a borderline prolonged bleeding time, and reported occasional hematuria, but was otherwise without symptoms. Absence of both kininogen species was proven by functional and immunological methods, and by lack of kinin formation both by plasma kallikrein and hog pancreas kallikrein. Prekallikrein was reduced, probably because the main part circulates complexed to high molecular kininogen. Activation of intrinsic fibrinolysis was grossly hampered, and cold activation of coagulation absent with epsilonaminocaproic acid and greatly retarded by dextran sulfate, kaolin and ellagic acid. Together with other evidence the findings indicate the following order of importance for contact activation in plasma--F.XII, high molecular weight kininogen, prekallikrein.

Adult↗
PubMed1990

[Folic acid deficiency can cause severe anemia and pancytopenia].

Pancytopenia is occasionally a consequence of folate deficiency. The most important differential diagnostic considerations are haematologic malignancies, aplastic anaemia and vitamin B12 deficiency. We discuss the problem as exemplified by three patients. Bone marrow examination and determination of blood concentrations of vitamin B12 and folate will give the correct diagnosis.

Adult↗