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Biomedical subjects

A Lasota

Publications and source records attributed to A Lasota.

18 recordsLinked to original sources

Experimental osteoporosis--different methods of ovariectomy in female white rats.

UNLABELLED: Rats are currently principal laboratory animals, used to investigate osteoporosis. The aim of the study was to present and compare two operative methods of inducing osteoporosis in rats. MATERIALS AND METHODS: Ten 3 months old female Wistar rats were divided into two groups with five animals in each group. In the first group, ovariectomy was preceded by a mid-line dorsal skin incision, 3 cm long. After removing the ovary, the previous incision of the muscle required suturing. In the second group, ovariectomy was performed by two dorso-lateral incisions, approximately 1 cm long above the ovaries. With the use of a sharp dissecting scissors, the skin was cut almost together with the dorsal muscles and the peritoneal cavity was accessed. There was no need of muscle suturing. CONCLUSION: The operation, performed in the second group, was technically easier, less time consuming and less harmful for the used female white rats.

Animals↗

[Familial sarcoidosis. Report of 2 cases in brothers].

For many years a genetic predisposition to sarcoidosis has been considered likely, however no convincing evidence have ever been found. We report histologically proven cases of sarcoidosis in two brothers. Initially, the case of sarcoidosis was diagnosed in a 36-year-old male patient (II stage of radiological lesions) and 4 years later the case of sarcoidosis was diagnosed in 28-year-old younger brother of the first patient (III stage). The brothers did not live together but, in the same neighbourhood. We evaluated the active evolution of a disease by clinical, radiological, including high resolution computed tomography and functional methods as well as by evaluating cellular and soluble components of bronchoalveolar lavage fluid (angiotensin converting enzyme, protein, phospholipids). The above constitutes the first report on familial sarcoidosis recorded in Poland.

Adult↗

[Concentration of sialic acid in bronchoalveolar lavage fluid in selected interstitial pulmonary diseases].

Sialic acid is a component of cell membranes and it can take part in immunological processes with lymphocytes and neutrophiles. In the present work the concentration of sialic acid in BALF in selected interstitial pulmonary disease was studied (in sarcoidosis, pulmonary fibrosis, avian fanciers lung) and compared with the control group of healthy persons. The investigations were repeated during the observations. The patients were divided into active and inactive groups. The analysis included the results in 187 patients divided into 9 groups. Sialic acid was measured with colorimetric method with the use of Ehrlich's reagent. The growth of sialic acid concentration in supernatant of BALF was observed in the studied diseases. The increase of sialic acid occurs in inflammatory processes especially those with neutrophiles. The correlation of acid concentration with the percentage or the total number of lymphocytes in BALF was observed. It is specific that the concentration of sialic acid in BALF in patients with avian fanciers lung keeps growing even after the contact with the antigen was discontinued.

Adult↗

Stability properties of proliferatively coupled cell replication models.

To address the possibility that proliferative disorders may originate from interactions between multiple populations of proliferating and maturing cells, we formulate a model for this process as a set of coupled nonlinear first order partial differential equations. Using recent results for the asymptotic behaviour of the solutions to this model, we demonstrate that there exists a region of coupling coefficients, maturation rates, and proliferation rates that will guarantee the stable coexistence of coupled cellular populations. The analysis shows that increases in the coupling between populations may ultimately lead to a loss of stability. Furthermore, the analysis indicates that increases (decreases) in the maturation and/or proliferation rates above (below) critical levels will lead either to instability in the populations or the destruction of one population and the persistence of the other.

Cell Division↗

[Transthoracic lung biopsy (TBP)].

The results of transthoracic lung biopsy using the Nordenströms method are discussed. Basing on this technique lung biopsies were performed in 138 patients suspected of pulmonary malignancy. High diagnostic efficacy, simplicity of this method and low incidence of side effects characterize this method.

Biopsy↗

[Lavage of the whole lung in a patient with pulmonary alveolar lipoproteinosis].

The first in Poland procedure of whole lung lavage is reported. The patient had intravitally diagnosed pulmonary alveolar lipoproteinosis. Difficulties in an effective and safe performance of the procedure are discussed. Modernized methods of lung lavage in patients with severe respiratory failure due to pulmonary alveolar lipoproteinosis are described.

Adolescent↗

[Lipid proteinosis of the pulmonary alveoli--diagnostic difficulties].

It is the first polish case of diagnosis of alveolar lipid proteinosis diagnosed during life is described. The diagnosis was based on biochemical analysis and morphological assessment in electron microscope of the fluid obtained in bronchoalveolar large in a patient aged 18 years with disseminated radiological pulmonary changes. Diagnostic difficulties are discussed comparing them with the cases of this disease reported as yet in Poland. The importance of bronchoalveolar lavage for the diagnosis is emphasized.

Adolescent↗

Globally asymptotic properties of proliferating cell populations.

This paper presents a general model for the cell division cycle in a population of cells. Three hypotheses are used: (1) There is a substance (mitogen) produced by cells which is necessary for mitosis; (2) The probability of mitosis is a function of mitogen levels; and (3) At mitosis each daughter cell receives exactly one-half of the mitogen present in the mother cell. With these hypotheses we derive expressions for the alpha and beta curves, the distributions of mitogen and cell cycle times, and the correlation coefficients between mother-daughter (rho md) and sister-sister (rho ss) cell cycle times. The distribution of mitogen levels is shown to be given by the solution to an integral equation, and under very mild assumptions we prove that this distribution is globally asymptotically stable. We further show that the limiting logarithmic slopes of alpha (t) and beta (t) are equal and constant, and that rho md less than or equal to while rho ss greater than or equal to 0. These results are in accord with the experimental results in many different cell lines. Further, the transition probability model of the cell cycle is shown to be a simple special case of the model presented here.

Animals↗

Minimizing therapeutically induced anemia.

A model for erythroid production based on a continuous maturation-proliferation scheme is developed. The model includes a simple control mechanism operating at the proliferating cell level, and analytic solutions for the time dependent response of the model are derived. Using this model, the response of the erythron to a massive depletion of the proliferating cell compartment (due for example to cytostatic drugs or radiation) is calculated. It is demonstrated that a therapeutic measure designed to decrease the erythroid precursor maturation velocity may considerably ameliorated the deleterious effects of proliferating cell destruction. One way to decrease the erythroid cell maturation rate would be by having the patient breathe in an oxygen enriched atmosphere.

Anemia↗

The extinction of slowly evolving dynamical systems.

The time evolution of slowly evolving discrete dynamical systems xi + 1 = T(ri, xi), defined on an interval [0, L], where a parameter ri changes slowly with respect to i is considered. For certain transformations T, once ri reaches a critical value the system faces a non-zero probability of extinction because some xj psi [0, L]. Recent ergodic theory results of Ruelle, Pianigiani, and Lasota and Yorke are used to derive a simple expression for the probability of survival of these systems. The extinction process is illustrated with two examples. One is the quadratic map, T (r, x) = rx (1 - x), and the second is a simple model for the growth of a cellular population. The survival statistics for chronic myelogenous leukemia patients are discussed in light of these extinction processes. Two other dynamical processes of biological importance, to which our results are applicable, are mentioned.

Biological Evolution↗

[Usefulness of bronchoalveolar lavage for diagnosis of pulmonary tuberculosis. Case report].

The case of a 57 year old male with Wegener's granulomatosis is reported in whom the course of cyclophosphamide and prednisone treatment a subacute mycobacterial tuberculosis pneumonia evolved. The diagnosis was based on culture of Mycobacterium tuberculosis organisms from the bronchoalveolar lavage fluid. The authors discuss the role of bronchoscopy and bronchoalveolar lavage in the diagnosis of pulmonary tuberculosis.

Bronchoalveolar Lavage Fluid↗