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Biomedical subjects

B Sokołowska

Publications and source records attributed to B Sokołowska.

At least 19 recordsLinked to original sources
PubMed2006

Ventilatory augmentation by acute intermittent hypoxia in the rabbit.

This study seeks to determine the effects on respiratory function of acute intermittent hypoxia. The experiments were performed on anesthetized, spontaneously breathing rabbits. The experimental protocol consisted of 5 one-minute episodes of hypoxia (14% O(2) in N(2)) interspersed with three-minute normoxic recovery periods. Ventilatory variables, minute ventilation (MV) and its tidal and frequency components, were derived from the continuously recorded airflow signal. We found that MV progressively increased with each next hypoxic-normoxic cycle; the increases were driven by both ventilatory components. Ventilatory augmentation concerned both the stimulus (hypoxic) and recovery (normoxic) periods, but it was significantly greater in the former. The augmented ventilation was sustained for up to 30 min after the last hypoxic run, which suggests the appearance of ventilatory long-term facilitation. The results demonstrate that acute intermittent hypoxia consisting of a few hypoxic-normoxic cycles is capable of inducing appreciable ventilatory changes. Such changes reflect plasticity of the respiratory motor output developing on a short-term basis during ongoing cycles of hypoxia, which, in the present study, correlated with the number of hypoxic cycle. Ventilatory augmentation in response to acute cyclic hypoxic episodes may give insights into the mechanisms of respiratory improvement by intermittent hypoxic training, increasingly used in both sports physiology and medicinal approaches.

Animals↗
PubMed2005

Statistical evaluation of ventilatory patterns in response to intermittent hypoxia in the rabbit.

In the present study we investigated whether classical or non-classical statistical methods might be useful in the diagnosis of early changes evoked by intermittent hypoxia (IH) in an experimental model. The experiments were carried out in anesthetized, spontaneously breathing rabbits. IH consisted of 5 cycles of breathing 14% O(2) in N(2) for 1 min interspersed with 3 min normoxic intervals. The following ventilatory variables were evaluated: frequency breathing, tidal volume, and minute ventilation. The results indicate that IH had a progressively stimulatory effect on the baseline ventilation and on the hypoxic ventilatory responses. Further, the algorithms of the pattern recognition theory might be a suitable tool for the recognition of early ventilatory effects of recurrent hypoxic events in the IH model. The recognition of IH states may be useful in clinical and sports medicine.

Algorithms↗
PubMed2004

Second malignancies and Richter's syndrome in patients with chronic lymphocytic leukaemia treated with cladribine.

The increased frequency of second malignancies in chronic lymphocytic leukaemia (CLL) is well known. Moreover, antineoplastic therapy additionally increases the risk of secondary cancers. In this study, we analysed whether treatment with cladribine (2-chlorodeoxyadenosine, 2-CdA) during the course of CLL had an impact on the subsequent occurrence of either secondary solid tumours or Richter's syndrome. There were 1487 eligible patients, 251 treated with 2-CdA alone, 913 treated with alkylating agents (AA)-based regimens alone and 323 treated with both 2-CdA and AA. Median time from the start of CLL treatment to the diagnosis of secondary malignancy was 1.9 years (0.5-5.1 years) for the 2-CdA group, 1.8 years (0.3-7.9 years) for the AA group and 3.9 years (0.3-8.4 years) for the 2-CdA+AA group. A total of 68 malignancies were reported in 65 patients. Ten events were non-melanotic skin cancers and were excluded from the analysis, leaving 58 events in 58 patients. In the group of patients treated with 2-CdA alone, there were 15 (6.0%) cases, in the group of patients treated with AA alone there were 26 (2.8%) cases, and in the group treated with 2-CdA+AA there were 17 (5.3%) cases of secondary malignancies. The differences between the frequency of secondary malignancies in the 2-CdA and 2-CdA+AA versus AA alone groups were not significant (P=0.05 and P=0.06, respectively). Only lung cancers occurred significantly more frequently in the 2-CdA (2.8%) and 2-CdA+AA (2.2%) treated groups compared with the AA patients (0.3%) (P<0.001 and P<0.01, respectively). In conclusion, 2-CdA in CLL patients does not seem to increase the risk of secondary malignancies except for lung cancers. However, further studies are necessary to establish the real risk of lung cancer in CLL patients treated with 2-CdA.

Adult↗
PubMed2004

Ventilatory response to hypoxia in experimental pathology of the diaphragm.

In this study, we examined the usefulness of arterial blood gas variables, as changed by the hypoxic stimulus, in discerning various experimentally-induced conditions of diaphragm weakness in anesthetized cats. We defined three experimental situations (models): (i) intact muscle, statistical Class I, (ii) four degrees of muscle dysfunction (after sequential diaphragm denervation), Classes II-V, and (iii) entirely paralyzed muscle, Class VI. Responses to a hypoxic stimulus in the above-mentioned conditions were evaluated by using the methods of the pattern recognition theory. We found that before the hypoxic stimulus, with partial but of different severity denervation of the diaphragm, the k-nearest neighbor classifier (k-NN) assigned 100% of the classified cases to Class II (one phrenic nerve rootlet cut). In contrast, during hypoxia only 67% of cases were assigned to Class II, the remaining being spread throughout other classes of muscle weakness. When one limits the procedure to the extreme classes: Class I (intact diaphragm) and Class VI (totally denervated diaphragm), the k-NN picks out 33% and 50% cases of bilateral diaphragm paralysis before and during hypoxia, respectively. We conclude that any remaining innervations of the diaphragm ensure the functionally optimal level of lung ventilation that may waver when hypoxia develops.

Animals↗
PubMed2003

A pattern recognition method to distinguish gradual unilateral diaphragm paralysis in the cat.

This work deals with the application of a pattern recognition method to distinguish the degree of diaphragm paralysis after gradual unilateral sections of phrenic nerve rootlets in anesthetized, spontaneously breathing cats. The data set consisted of the features that characterize breathing pattern and of phrenic nerve amplitude. The method called for stratification of 6-dimensional vectors into three classes: intact, partial, and complete unilateral phrenicotomy, which offers the possibility to construe the classification rule on the basis of the information contained in a set of feature vectors with the known class-membership. This method deals with the use of a distance function as a measure of similarity between two feature points. The results show that the degree of diaphragm paralysis could be recognized with the probability higher than 90%. Distinguishing the severity of diaphragmatic dysfunction and the compensatory strategies of the respiratory system, knowing only a handful of basic values describing breathing pattern, might have a practical meaning in respiratory emergencies.

Animals↗
PubMed1997

[Diaphragmatic electromyogram and respiratory pattern after unilateral and bilateral partial denervation of the diaphragm in the cat].

In the present study we investigated the mechanism of early respiratory compensation of partial paralysis of the sternal and lateral diaphragm due to an unilateral or bilateral section of the C5 rootlet of the phrenic nerves in anesthetized cats. Compensatory effects were evaluated from the recordings of the bilateral diaphragmatic EMGs, neural respiratory pattern and ventilation. The results of the study demonstrate that successive C5 denervation of the diaphragm caused a decrease in the ipsilateral diaphragmatic EMG. Bilateral C5 section evoked an up to 10 percent decrease in minute ventilation. The compensation of the unilateral and then bilateral partial impairment of the muscle function was achieved always by an increase in the neuromuscular projection to the currently contralateral diaphragm. Neural mechanisms of compensation involve a general increase in the respiratory drive, expressed mostly as an increase in the frequency of breathing. The contribution of afferent respiratory muscles to these mechanisms is likely.

Animals↗
PubMed1994

[Evaluation of platelet hemostasis in patients with chronic renal failure].

The greatest role in the development of haemostasis disturbances in patients with chronic renale failure (CRF) is ascribed to the platelets. The purpose of the work was study of basic parameters of platelet haemostasis in patients with CRF treated both conservatively and subjected to repeated haemodialyses. A correlation was also sought between the degree of renal failure intensity and haemostasis disturbances. The subject of the study were 18 patients treated conservatively and 21 patients subjected to repeated haemodialyses. In the patients the following was determined: platelet count, bleeding time, aggregation by Breddin and Born methods, availability of platelet factor 3 (PF3), activity of platelet factor 4 (PF4), and also the concentrations of urea, creatinine, uric acid, albumins, sodium, potassium, calcium, haemoglobin, and red blood cell count, haematocrit, and endogenous creatinine clearance. In non-dialysed patients, in relation to the control group, unchanged platelet count was shown as well as prolonged bleeding time, increased aggregation assessed by the Breddin method but unchanged by the Born method, decreased PF3 availability and unchanged PF4 activity. Aggregation and bleeding time were correlated with the degree of uraemia progression assessed on the basis of biochemical parameters, while platelet count was correlated only with urea concentration. In haemodialysed patients unchanged platelet count was demonstrated as well as prolonged bleeding time, increased aggregation assessed by the Breddin method but simultaneously decreased in the Born method, increased PF3 availability and unchanged PF4 activity. In this group of patients the correlations were only found between bleeding time and haemoglobin concentration, haematocrit, and red blood cell count.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[Effect of lovastatin on platelet function in hypercholesterolemic patients].

18 patients were studied with primary hypercholesterolemia (type II according to Fredricksen) and fasting cholesterol level during low fat diet above 250 mg/dl. Blood samples were taken: I--before lovastatin administration on diet, II--after 4 weeks administration of 20 mg, III--after 4 weeks of 80 mg and IV--4 weeks after the drug discontinued. The following tests were performed: platelets aggregation induced by ADP and adrenaline, PF3 and PF4, platelet MDA, serum triglycerides, total cholesterol, HDL-cholesterol and LDL-cholesterol. Before treatment patients showed significant platelets hyperaggregation and MDA concentration comparing to the control group. During the drug administration significant lowering of platelets MDA concentration, was observed small but significant HDL cholesterol level increase which correlated with platelet MDA concentration. Availability of PF3 and release of PF4 did not change during study.

Adult↗
PubMed1991

[Chemotherapy and immunomodulating treatment of patients with multiple myeloma].

Prospective studies were carried out on the effectiveness of various treatment methods in 208 patients with plasmocytic myeloma. In 102 patients induction therapy was based exclusively on melphalan, in 106 cases polychemotherapy was used including vincristine, melphalan, carmustine, cyclophosphamide and prednisone. The differences in the per cent of patients with good response to treatment and in the survival time after treatment beginning were statistically not significant between these groups which suggests that polychemotherapy begun from the diagnosis of the disease is justified in patients with large mass of the neoplasm and poor prognostic factors. In 45 patients chemotherapy was supported by administration of immunomodulatory agents, including calf thymus extract in 25 cases, levamisole in 18 and interferon in 2. It was observed that maintenance of remission with chemotherapy and with immunomodulatory agents calf thymus extract or levamisole prolonged the survival of the patients. In cases of leucopenia the use of calf thymus extract facilitated chemotherapy by stimulation of myelopoiesis.

Adult↗
PubMed1990

The effect of sulphinpyrazone and alpha-tocopherol on platelet activation and function in haemodialysed patients.

In 30 patients on chronic haemodialysis treatment the platelet activity and function were studied before and during antiplatelet therapy with alpha-tocopherol and sulphinpyrazone. In both kinds of treatment a significant decrease of ADP-induced and spontaneous aggregation was observed. Sulphinpyrazone exerts an inhibitory effect not only on platelet aggregation but also on platelet factor 3 and provokes a significant prolongation of the bleeding time.

Adult↗
PubMed1990

[The comparison of serological tests used in diagnosing active toxoplasmosis].

ELISA kits from different commercial firms were evaluated and compared with monoclonal immunosorbent agglutination test ISAGA for detection anti-T. gondii IgM antibody. The results presented in this study show that both ELISA-IgM tests, as well from Organon, as from Abbott firms promise to be of the same value for the diagnosis of acute acquired and congenital toxoplasmosis.

Adult↗
PubMed1990

[Disorders of blood platelet homeostasis in patients with multiple myeloma before the treatment and during remission].

In 28 patients with plasmocytoma selected parameters of primary haemostasis were studied before treatment and 6-9 months later, in remission. We evaluated spontaneous aggregation, aggregation induced by ADP and adrenaline, platelet factor 3 availability and the realising platelet factor 4. Significant disturbances of primary haemostasis were particularly marked in patients with a high monoclonal protein concentration (greater than 3 g/dl). During remission an increase of platelet aggregation was noted. Its values, however, remained lower than in the control group.

Adult↗
PubMed1990

[Activation and functions of blood platelets in patients with diabetes mellitus type 1 before and during the treatment with indobufen].

In 18 patients with type I diabetes the effect was studied of 10 days of Indobufen administration in daily doses of 400 mg on the activation and function of platelets. Spontaneous and ADP and adrenaline-induced aggregation, adhesiveness, platelet factors 3 and 4, and generation of malonyldialdehyde (MDA) in platelets were investigated. The results were compared with similar results in the same group prior to the treatment and in a control group of 19 healthy subjects. Highly significant inhibition was noted of spontaneous inhibition and that evoked by adrenaline and ADP, and a considerable reduction of MDA generation by platelets. These results indicate that the new platelet inhibitor--Indobufen, effectively inhibiting platelet activation and function may prevent development of thrombotic complications of diabetes.

Administration, Oral↗