Biomedical subjects

T Jankowski

Publications and source records attributed to T Jankowski.

At least 19 recordsLinked to original sources

PubMed2005

Expression of the P65 gene in gastric cancer and in tissues with or without Helicobacter pylori infection.

A 65-kDa tumor-associated protein (P65) is a potential non- specific tumor marker expressed by many types of tumor cells. Our recent studies indicate that P65 gene expression is connected with poor prognosis for the patients with colorectal cancer. In the present study P65 gene expression was determined by means of RT-PCR in the group of 22 gastric cancer and adjacent normal gastric mucosa. Its presence was correlated with some parameters of clinical staging. P65 gene expression was also determined in 102 tissue antral gastric endoscopic biopsy specimens from the patients suspected of H. pylori infection. The presence of H. pylori infection was determined by urease test. We found that in the group of gastric cancers, similarly to colorectal cancer, P65 gene expression was connected with poor clinicopathological parameters as T3, lymph nodes and distant metastases. There was no dependence between P65 gene expression and H. pylori infection. However, more often P65 gene expression was detected in the group of infected men than women. There was also a statistically significant dependence between age and P65 gene expression in the group of people above 60 years old. It could be then postulated that P65 gene expression is connected with poor prognosis for the patients suffering from gastric cancer and that this expression does not depend on H. pylori infection.

Adult↗

PubMed2004

Monitoring the progress of infection and recombinant protein production in insect cell cultures using intracellular ATP measurement.

Several monitoring methods used to predict viable cell density have been the subject of extensive studies, including oxygen uptake rate, carbon dioxide evolution rate, optical density, NADH-dependent fluorescence and relative permittivity measurement. We propose intracellular ATP determination by bioluminescence assay to monitor the progress of baculovirus infection and recombinant protein production in insect cell cultures. We found that the ATP content in viable cells increased after virus addition. The increase in the ATP level was observed until the maximum recombinant protein accumulation was reached. At maximum product yield, the specific ATP content significantly decreased. Results obtained in both batch and fed-batch cultures demonstrated that the specific ATP level could be considered as a good indicator of recombinant protein productivity. Monitoring the cellular ATP content after viral infection makes it possible to define the optimum time for product harvest. The main advantage of applying the ATP assay as an index of the progress of infection and recombinant protein synthesis is its short time and sensitivity.

Adenosine Triphosphate↗

PubMed2004

Short communication: effect of leptin gene polymorphisms on breeding value for milk production traits.

New molecular techniques focused on genome analysis open new possibilities for complex evaluation of economically important traits in farm animals. Milk production traits are typical quantitative characteristics controlled by a number of genes. Mutations in their sequences may alter animal performance as well as their breeding values. In this study, we investigated the effect of 3 restriction fragment length polymorphisms (RFLP): HphI, Kpn2I, and Sau3AI in the leptin gene, on bull breeding values for milk, fat, and protein yield, and fat and protein content. One hundred seventeen Polish Black and White AI bulls were genotyped. Pedigree analysis indicated a relatively close relationship between the bulls. Statistical analysis indicated that the HphI polymorphism has a significant effect on milk and protein yield. Animals with the TT genotype had approximately 2x higher estimated breeding values for milk and protein yields. No effect was found for the other 2 polymorphisms.

Animals↗

PubMed2004

Allochronic differentiation among Daphnia species, hybrids and backcrosses: the importance of sexual reproduction for population dynamics and genetic architecture.

Seasonal dynamics of the abundance, sexual reproduction and genetic architecture in a Daphnia hyalina-galeata hybrid complex were studied in the large and deep Lake Constance. We found evidence for the occurrence of first and second order hybridization. Our study revealed strong differences between the parental species not only regarding their seasonal dynamics, genetic architecture and diversity, but also their sexual reproductive behaviour. The overwintering D. hyalina showed low genetic diversity, no genetic differentiation during the season, and reproduced sexually in autumn, whereas D. galeata reached higher levels of genetic diversity, reproduced sexually in early summer, and exhibited changes in genetic structure during the season, but was only present from spring to autumn. However, in both species sexual reproduction was a rare event, and daphnids, including hybrids, reproduced predominantly asexually. This allows long-term persistence of hybrids as well without continuing hybridization events. Within all variables studied, F1 and F2 hybrids showed an intermediate pattern, whereas proposed backcross hybrids were more similar to their respective parentals. These differences in phenotype as well as significant differences in pairwise Fst values between parentals suggest that gene flow seems to be relatively low in the Lake Constance hybrid system. We found evidence for unidirectional introgression by backcrossing from D. galeata to D. hyalina and found a decrease in at least one of the proposed introgressed alleles in the hyalina-backcross while the season progressed. Our findings suggest allochronic differentiation within this hybrid population and different microevolutionary trajectories of the parental species, which will be discussed in the light of the ongoing reoligotrophication process of Lake Constance.

Animals↗

PubMed2001

Determination of pore diameter and molecular weight cut-off of hydrogel-membrane liquid-core capsules for immunoisolation.

The exclusion limit expressed as the largest pore size of capsules composed of hydrogel Ca-alginate membrane and hydroxy-propyl-ammonium starch liquid core considered as the immunoprotective system has been determined by means of inverse size exclusion chromatography with dextran molecular weight standards. The exclusion limits of the capsules were not influenced by the change of starch concentration in the core solution from 4 to 6% but were influenced by the change in alginate concentration in the membrane from 0.5 to 1.0%, causing the membranes to be less permeable. It was found that the diameter of the largest pores in hydrogel membranes was in the range 7.2-8.0 nm. Based on the relationship between solute size and its molecular weight, the capsules had an approximate exclusion limit of 21-25 kD for dextran and 78-103 kD for protein, which is sufficient to block the antibodies penetrating through the membrane.

Alginates↗

PubMed2000

Characterisation of small molecules diffusion in hydrogel-membrane liquid-core capsules.

The overall diffusion coefficients for several low molecular weight solutes, such as glucose, fructose, sucrose, lactose, and vitamin B(12) have been determined in Ca-alginate membrane liquid-core capsules using the unsteady-state method following the release of solutes from the capsules to a well-stirred solution of limited volume. The diffusion coefficients obtained for saccharides were 5-20% lower than the corresponding diffusivity in water while for vitamin B(12) about 50% that of water. The diffusion coefficients of the investigated capsules were not influenced by the change in alginate concentration in the capsule membrane from 0.5 to 1.0%. Lower diffusivities and higher deviations from the diffusivity in water were obtained for higher molecular weight solutes.

Journal Article↗

PubMed2000

The mechanical properties of fresh and cryopreserved arterial homografts.

OBJECTIVES: To assess the effect of cryopreservation on the elasticity and compliance of arterial allografts. MATERIALS AND METHODS: Iliofemoral segments of arteries and veins harvested from multiorgan donors were divided into two groups: fresh-control, tested for 24 hours after harvesting, and cryopreserved in liquid nitrogen after pretreatment with 20% dimethylsulphoxide and stored for an average time of 22 days. Vessel wall elastic properties were evaluated from the stress-strain relationship in a specially designed test cell fixed to the Instron Universal Testing Machine. RESULTS: The elastic modulus of the artery control group (1.54+/-0.33 MPa, n=20) was not significantly different from the cryopreserved group (1.69+/-0.61 MPa, n=15). Similarly, values for unfrozen veins (3.11+/-0.65 MPa, n=47) were not significantly different from those of frozen samples (2.71+/-0.85 MPa, n=38). Control compliance (6. 86+/-1.79x10(-5)%/Pa, for arteries; 3.84+/-0.81x10(-5)%/Pa, for veins) was similar to that of the cryopreserved group (6.66+/-1. 80x10(-5)%/Pa, for arteries; 4.16+/-1.21x10(-5)%/Pa, for veins). CONCLUSIONS: Cryopreservation maintains the important elastic properties of arterial and venous allografts during average storage time of 22 days.

Biomechanical Phenomena↗

PubMed2000

[Serum concentration of selected neoplasm markers: CA15-3, TPS and CEA in women with diagnosed breast benign disease].

The aim of the study was the assessment of serum concentrations of selected neoplasmatic markers: CA15-3, TPS and CEA in women with established diagnosis of benign breast disease (BBD) using hormone replacement therapy (HRT) for average 3 years. 120 women with BBD were divided to 2 groups: HRT-users (n1 = 24) and HRT-non-users (n2 = 96). 31 healthy, regularly menstruating, age-matched women served as control group. Concentrations of all markers were measured with immunoradiometric methods. In all groups serum concentrations of measured markers were within normal range. We conclude that hormone replacement therapy has no influence on serum concentrations of CA15-3, TPS and CEA.

Adult↗

PubMed1982