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Biomedical subjects

J Jakubik

Publications and source records attributed to J Jakubik.

29 records · Page 2Linked to original sources

Cell-mediated immunity in Aujeszky disease virus infected pigs. I. Lymphocyte stimulation.

The appearance of cell-mediated immunity was studied in Aujeszky diseased pigs with the aid of the in vitro stimulation of sensitized lymphocytes. The first cell-mediated immunity reaction of lymphocytes occurred 4 days after infection. From day 7 to 35, the latest day tested, the reactions were most marked with lymphocytes from lymph nodes and spleen, whereas blood and thymus lymphocytes reacted less frequently; bone marrow lymphocytes showed no response. Reinfection did not considerably enhance lymphocyte reactivity. Humoral immunity was demonstrated a few days later than cell-mediated immunity. Neutralizing antibodies were first detected at day 7, reaching optimal titers at day 14. Complement fixing antibodies were detected from day 14 onward. Reinfection caused a very weak booster effect only on neutralizing antibody production. The sensitivity of the neutralization test could be enhanced up to sixfold by the addition of fresh guinea pig complement. It is concluded that cell-mediated immunity influences the early stage of infection with Aujeszky disease virus when humoral immunity is not yet demonstrable or yet rather low. Lymph nodes and spleen are apparently of special importance for the appearance of ADV-reactive lymphocytes.

Animals↗

Molecular characterization of cellular proteins from colorectal tumors.

AIMS AND BACKGROUND: Recent evidence has suggested that progressive stages of colorectal tumorigenesis can be defined by a sequence of genetic events characterized by altered expression of certain genes and the appearance of cancer-specific proteins. Although the significance of these events is still not clear, expression of cancer-specific protein components may be directly involved in the neoplastic transformation. The purpose of the present study was to compare molecular characteristics of cellular proteins from human colorectal tumors and normal colonic mucosa. METHODS: Normal mucosa and colorectal tumors from 18 patients were fractionated by a differential centrifugation scheme into four cellular fractions, i.e., nuclear, mitochondrial (10P), microsomal (100P) and cytosolic (100S). The proteins of these fractions from normal and tumorigenic mucosa were analyzed by one-dimensional polyacrylamide gel electrophoresis followed by Coomassie brilliant blue R-250 and silver nitrate staining. Nuclear proteins from normal and neoplastic tissues which had revealed the most significant diversities were further characterized by two-dimensional gel electrophoresis. Electrophoretically cancer-specific nuclear proteins in the molecular mass zone 35-40 kDa were used as immunogen to produce rabbit polyclonal antibodies. RESULTS: Electrophoretic analysis by one-dimensional gel electrophoresis showed clear differences in molecular characteristics of cellular proteins between normal and tumorigenic mucosa, especially among nuclear fractions. The latter were also confirmed by their two-dimensional electrophoresis results. Rabbit antibodies raised against electrophoretically specific nuclear proteins characterized by molecular mass of 35-40 kDa cross-reacted with 36 kDa polypeptide in 15 of 18 (83.3%) studied nuclear fractions of colorectal tumors but not with any normal mucosa. In some cases, nuclear cancer-associated components of 38 and 40 kDa were also recognized by these antibodies. CONCLUSIONS: During colorectal carcinogenesis, specific expression of several nuclear proteins takes place. One of them, the polypeptide of 36 kDa not found in normal colonic epithelium, was shared by over 83% of the studied carcinomas despite variations in detailed cancer properties. This particular nuclear protein may be considered as a potential marker for the colon malignancy.

Carcinoma↗

[Contamination of human milk with nitrates and nitrites].

Human milk nitrates and nitrites were assayed colorimetrically. Colostrum samples were collected on the 3rd postpartum day from 59 women inhabiting Puławy region and being potentially exposed to nitrogen compounds emitted from the industrial sources. Thirty five Lublin inhabitants serving as a control group were matched in age, parity and duration of pregnancy. Geometric mean value of nitrates and nitrites concentration in the human milk being 2.83 mg/L and 0.46 mg/L, respectively were higher in the examined group than those in the control group /2.76 mg/L and 0.32 mg/L/ but difference was statistically insignificant. Ratio of nitrates and nitrites in the examined samples was 7.38 on the average and the concentration of those compounds was related statistically significantly /p less than 0.001/. The average daily intake of nitrates and nitrites by the breast-fed neonates was 0.12 mg/kg body weight and 0.02 mg/kg body weight, respectively. These values did not exceed corresponding ADI recommended by the Joint Expert Committee of FAO/WHO in none case. Significantly positive correlation of examined mothers' age and parity with nitrates content in their colostrum was seen. In view of the obtained results is may be assumed that the examined colostrum samples contain low amounts of both nitrates and nitrites.

Breast Feeding↗