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Biomedical subjects

T Mazur

Publications and source records attributed to T Mazur.

At least 19 recordsLinked to original sources
PubMed1999

Secondary amoebic eye infections in mice due to Acanthamoeba sp.

The aim of the present study was to determine the occurrence of eye infections accompanying the infection of the central nervous system and to demonstrate the possible tissue affinity of different strains of amoebae in subsequent infections. The results obtained demonstrate a clear correlation between the occurrence of eye infection and the degree of virulence of the strains. Amoebae isolated from eyeballs and other organs of dead mice did not exhibit any specificity in relation to the organs in subsequent infections. Irrespective of the place of isolation--be it eye or brain--in the subsequent passages, the amoebae were most often found in the brain and lungs, followed only then by the eye of the infected animals.

Acanthamoeba↗
PubMed1999

Extracerebral infections of Acanthamoeba spp. in mice. pathomorphological changes in tissues of infected animals.

A variety of Acanthamoeba spp. pathogenic strains were isolated from water pools in the area of Poznań. In many cases amoebae invaded lungs, kidney heart, liver and diaphragm causing significant changes in these Organs. The presence of amoeba outside of CNS was found mainly in the early periods of infection. Amoeba isolated from different organs of dead animals did not exhibit any specificity in relation to the organs in following infections. Infection with both low-and high-virulent strains resulted in pathomorphological changes of similar character. However, changes induced by low-virulent parasites developed later and were less extensive.

Acanthamoeba↗
PubMed1997

Biosynthesis of prostaglandins in pathogenic and nonpathogenic strains of Acanthamoeba spp.

The aim of the present study was to examine the biosynthesis of prostaglandins and to investigate factors conditioning their biosynthesis in pathogenic and nonpathogenic strains of Acanthamoeba spp. We established that the activity of the synthase of prostaglandins was almost identical in pathogenic and non-pathogenic strains and that the synthesis of endoperoxide prostaglandins was similar to that of other organisms up to the point at which prostaglandin H2 was produced. The course of biosynthesis in vitro can be activated by various compounds such as glutathione, albumin, and p-chloromercuribenzoic acid (p-CMB), which are either activators or inhibitors of the enzymes. We suggest that the course of biosynthesis of prostaglandins in vivo is most probably activated by tissues or constitutional liquids surrounding the parasites.

Acanthamoeba↗
PubMed1995

The duration of the cyst stage and the viability and virulence of Acanthamoeba isolates.

The viability of Acanthamoeba cysts after they have been stored in water at 4 degrees C for a period of 24 years was determined and to estimate their present degree of virulence as compared to its primary values. The viability of 17 amoebae isolates was examined using the eosin exclusion and in vitro excystation on agar plates (NNE). After the period of 24 years, only 3 isolates were found dead. The remaining 14 isolates after inoculation on NNE gave rise to new subcultures, although the percentage of living cysts measured by eosin exclusion was low (0-5%). Separate groups of mice were inoculated intranasally with 10 subcultures characterised by varying primary virulence. It was found that in 8 groups the mice were invaded (at varying degree), and some of them died. Taking into consideration the fact that some of the examined isolates completely lost their virulence only after 8 years of the in vitro cultivation, the obtained results are very intriguing. On the ground of these results one can assume that in the natural environment the period of viability for a cyst may be not shorter than 25 years, and, which is even more essential, they can maintain their invasive properties.

Acanthamoeba↗
PubMed1994

The effect of the passages of Acanthamoeba strains through mice tissues on their virulence and its biochemical markers.

The aim of this study was to determine the enzymatic differences in the process of increasing the degree of virulence in attenuated Acanthamoeba strains as well as strains freshly isolated from the natural environment. The data obtained in our studies indicate that by intranasal infection of mice, one can restore virulence in primary virulent strains and make virulent strains that primarily were noninvasive. The levels of peroxidase and proteinase activity measured thoroughly correlated with the increase in the degree of virulence observed during the process of making the amoeba virulent by inoculating them into mice. We observed that in cases in which the activity of peroxidase and proteinase was higher than 0.150 units/mg protein and 8 units/mg protein, respectively, some of the animals infected with the strains showing this activity of peroxidase and proteinase died. In nonvirulent strains as well as in poorly virulent strains, we observed a decidedly lower activity of these enzymes.

Acanthamoeba↗
PubMed1993

Biochemical markers of pathogenicity and virulence of Acanthamoeba sp. strains.

The aim of our study was to demonstrate a possible correlation between some biochemical and biological markers of the degree of virulence of the investigated strains of Acanthamoeba sp. The results obtained demonstrated a significant correlation between the activity of proteases, peroxidases, and superoxide dismutase and the degree of virulence of the strains as previously defined by tests on mice. The results also proved that the strains that killed some of the infected mice were characterized by the highest value recorded for the activity of peroxidase and the lowest value obtained for the activity of superoxide dismutase.

Acanthamoeba↗
PubMed1993

[Extracerebral infections of Acanthamoeba spp. in mice].

A variety of Acanthamoeba spp. pathogenic strains were isolated from water pools in the area of Poznań. In many cases amoebae invaded in mice, beside central nervous system (CNS) also lungs, kidney, heart, liver, diaphragm and eyeballs, causing significant changes in these organs. The presence of amoebae outside of CNS was found mainly in the early period of infection. Amoebae isolated from different organs of dead animals did not exhibit any specificity in relation to the organs in following infections.

Acanthamoeba↗
PubMed1993

Proteolytic enzymes of pathogenic and non-pathogenic strains of Acanthamoeba spp.

The aim of this work was biochemical characterization and classification of proteinases in pathogenic and non-pathogenic strains of Acanthamoeba spp. The authors showed two proteinase (acid 35 kDa and alkaline 65 kDa) which could be separated electrophoretically. Acid proteinase was inhibited by serine proteinase inhibitors such as DIFP. The second enzyme which was active at alkaline pH, was enhanced by EDTA and inhibited by iodoacetate (IAA) and (p-CMB) p-chloromercuribenzoate. These substances are known to inhibit cysteine type proteinases. The alkaline proteinase was more distinctively active in pathogenic strains and belongs to cysteine class (EC 3.4.22), whereas the acid proteinase was similar active in pathogenic and non-pathogenic strains and belong to serine class (EC 3.4.21).

Acanthamoeba↗
PubMed1991

Pubertal disorders. Psychology and clinical management.

The behavioral data reviewed herein must be viewed with caution. Although there are reports that adhere to rigorous methodology, these are the exception. Most reports do not adequately describe either the methodology used or their sample. Subjects are often of mixed endocrine diagnoses, and sometimes the results are of both boys and girls. All of these pitfalls make interpretation of results difficult and limiting. With this in mind, the following conclusions are offered. The majority of behavioral data on precocious puberty comes from studies of IPP in girls. Cognitively, IPP has been associated with average to high-average intelligence. Purportedly, the finding of lower visual-spatial skills than verbal skills in early maturing boys and girls has received equivocal support by cognitive studies of IPP individuals. Similarly, clear differences in hemispheric lateralization have not been demonstrated. Aside from increased somatic complaints during the nonmenstrual phases of their menstrual cycle, girls with IPP show a spectrum of behavior adjustments. Major psychopathology is rare. Clearly, their early development makes them look older than their actual age, which probably alters the expectations others have for them. Psychosexually, however, IPP girls develop in concert with their chronologic age and social experience, rather than their early biologic maturation. However, recent reports suggest a modest influence of hormones. In summary, these studies support an interactionist theory of human psychosexual development. Research data on IPP girls suggest that they do not significantly differ from girls who are early maturers but within the normal range. Research on these girls indicates that most negotiate their puberty without severe problems. There has been less research on IPP boys because it occurs so rarely. Most of what is understood about precocious puberty in boys comes from boys with precocious puberty secondary to poorly controlled CAH. Behavioral data on individuals with delayed puberty come almost exclusively from boys. Although CD appears to be the most frequently diagnosed form of delayed puberty and does not reflect a known pathologic process, men with CD as well as those with organic disorders appear to be at risk for psychosocial and psychosexual difficulties. These difficulties are not severe forms of psychopathology. Rather, they probably represent problems negotiating the expected adolescent lessons of psychosocial development with a physique that places them at a disadvantage. They clearly look younger than their actual chronologic age. Cognitively, as with the children with precocious puberty, there is no evidence of intellectual impairment associated with delayed puberty.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1990

Management of male pseudohermaphroditism: a case report spanning twenty-one years.

Management of infants born with ambiguous sex organs requires the close collaboration of a team of professionals: pediatric endocrinologist, pediatric psychologist, gynecologist, and surgeon. The interdisciplinary teamwork of a group of professionals is described in the case of a patient announced at birth as a male but within days reannounced and reared as a female. Over the next 21 years, she became completely aware of her endocrine condition, including its medical classification (male pseudohermaphroditism), her chromosomal (46 XY) and gonadal (testes) status, and her early history of male sex assignment. The clinical management described herein helped this person deal effectively with her condition despite unsuccessful reconstructive vagal surgery. Substantiation of this is provided by the patient's personal comments.

Adolescent↗
PubMed1989

[Value of the color test in assessing the viability of cysts of Acanthamoeba sp].

The eosin colour test estimating the viability of cysts was compared with the method of in vitro excystation on agar substrate (NNE). Single cysts were studied, isolated from populations stored under sterile conditions in water at 4 degrees C for a period ranging from a few days to 16 years. It has been found that the inoculations of single cysts (805 cysts) on the NNE substrate allow a precise determination of the percentage of living cysts. All the cysts stained with eosin, incubated on such a substrate proved to be dead, while the non-staining cysts ex-cistated with varying percentage. Thus, among the non-staining cysts of Acanthamoeba after 2-4 years of storage at 4 degrees C 89.2% excystated while the remaining ones were dead. After 16 years of storage only 29.8% nostaining cysts excystated. Very similar values (89.6 and 28.5% respectively) were obtained when determining the percentage of living cysts with the colour test. The eosin test has proved to be a good method of the estimation of the viability of cysts of Acanthamoeba.

Acanthamoeba↗
PubMed1989

[Prevalence of Entamoeba histolytica and other intestinal protozoa among the inhabitants of Poznan province over a period of 30 years].

The aim of the study was to present the past and actual prevalence of Entamoeba histolytica and other intestinal protozoa in Poznań Province. Although in Poland there are only few accurate data concerning the prevalence of intestinal protozoa, the results of some studies were found reliable. In a survey conducted in 1958 in an orphanage in Poznań (Kasprzak and Karlewiczowa) the intestinal protozoa were found with high prevalence (Table 1). After six years this prevalence decreased considerably (Karlewiczowa and Kasprzak, 1964). Because at the same time such a decrease in intestinal protozoa prevalence, especially that in Entamoeba coli, was observed in the whole population of the Poznań Province, long-term surveys were undertaken. The diagnosing of intestinal protozoa in faeces of 4165 persons, performed at more points in time in the period of 1963 to 1986 in the Poznań Province, were conducted by the same highly skilled staff. Decreasing rates of infection were seen for each amoeba species at nearly each point in time, particularly in the first eight years of observation (Table 2). By using the "amoebic index" and "amoebic prevalence rate" in assessing epidemiological factors (acc. WHO, 1969), the considerable reduction in both indices should be accounted for the improvement of the sanitation and socio-economic status in our country. After the Second World War some Polish authors expressed the fear that after returning to the country, the Polish soldiers who had fought in the endemic regions of invasive amoebiasis, infected with E. histolytica, would constitute sources for spreading amoebiasis and that the disease would be a nucleus of a new, hitherto unknown, social calamity in Poland. Fortunately, the fear did not come true. Although in this country the infection with amoebae, also with E. histolytica, decreased considerably after several years, unfortunately, some opinions still prevail, being the source of an amoebo-mania in the medical staff and corresponding amoebophobia in the patients.

Amebiasis↗