Quantitative analysis of estrogen receptor mRNA in human endometrium throughout the menstrual cycle using a real-time reverse transcription-polymerase chain reaction assay

We conducted a quantitative analysis of ERalpha and ERbeta mRNA expression in normal human endometrium throughout the menstrual cycle in regular menstruating premenopausal women, taking advantage of this real-time PCR assay. Endometrial dating was determined from the histology of the endometrium and classified into: proliferative endometrium and secretory endometrium. Both ERalpha and ERbeta mRNA expression were detected in all endometrial samples at both proliferative and secretion phase. However ERalpha mRNA expression level was higher than that of ERbeta specially during proliferative phase. These results suggest that estrogenic effects occur predominantly through ERalpha than ERbeta.

Quantitative analysis of estrogen receptor-alpha and -beta and exon 5 splicing variant mRNA in endometrial hyperplasia in perimenopausal women

We used real-time reverse transcription-polymerase chain reaction (QRT-PCR) to detect wild-type ERalpha and ERbeta and their isoforms as well as exon 5 splicing variant mRNA ERalpha in various types of endometrial hyperplasia in perimenopausal women. Our data suggest that the exon 2 and 7 deletion ERalpha mRNA isoforms are present in endometrial tissue undergoing various hyperplastic states. Wild type ERbeta mRNA and their isoforms 2, 4, 5, 6 were observed in each type of assessed endometrial specimens, and ERalpha/delta5 was found only in hyperplasia complex group.

Quantification of P21 mRNA in biopsy specimens of colon tissue at different stages of neoplastic transformation

Induction of the P21 protein is an integral part of cell growth arrest associated with the cellular response to senescence or damage. Changes in the P21 protein level are often observed in tumour cells and it is suggested, that they correlate with malignancy. We studied the P21 gene expression at the mRNA level in biopsy specimens from colitis ulcerosa, adenomas and adenocarcinomas using TaqMan assay. Our results showed, that quantity of the P21 transcript was evidently lower in the cases with adenocarcinomas than in the cases with colitis ulcerosa or adenomas.

BCL2 and BAX mRNA concentration profile in fibrillary astrocytoma

A high level of the BCL2 protein and the lack of apoptosis promoting protein BAX are beginning to be treated as markers of cellular resistance to anti-neoplastic drugs. The object of the study were specimens from stereotactic biopsy of Astrocytoma fibrillare in the central brain area, inaccessible to conventional surgery. The cytological preparations have been evaluated with histopathological and immunohistochemical methods in order to determine the origin of the tumour and assess cell proliferation activity. The molecular analysis conducted in order to determine the sensitivity of the tumour to radio- or chemotherapy included the determination of the number of mRNA BCL2 alpha and beta molecules and of BAX in 1 microg total RNA obtained from microscope slides. A higher expression of BAX than of BCL2-alpha is a prognosis for a positive result of chemo- or radiotherapy. A trace number of mRNA BCL2-beta molecules and a smaller number of mRNA BCL2-alpha molecules than mRNA BAX is a good prognosis for therapy.

Quantitative RT-PCR assay for mRNA of VEGF and histone H4 in the determination of proliferative and angiogenic activity in vulvar pathology

Proliferative and angiogenic activity of tissue specimens taken from women with various vulvar pathologies were evaluated by determining the number of mRNA VEGF molecules and H4 histone mRNA molecules, by means of the QRT-PCR (TaqMan) technique. Following a cluster analysis the results, where normalised. Euclidean distances were used, all the cases were classified into three groups of pathologies. Group I included low degree vulvar pathologies, group II included high degree vulvar pathologies and group III included vulvar pathologies with high proliferative and angiogenic activity. Significant differences were found in the proliferative and angiogenic activity between groups I and III, and between groups II and III, while no statistically significant differences were found between groups I and II.

Differentiation strategies of alternative splicing variants mRNA estrogen receptor-alpha

From the clinical point of view recognizing the concentrations and type profile of isoforms could be of significant practical importance. The aim of the study is designed QRT-PCR reaction to assess profile of mRNA ER-alpha and their isoforms. Theoretical part of the study was made according to computer program and available Genbank database. To detect a isoform one of the primer was designed to hybridize within exon-border linked in alternative splicing. The study presents the differentiation strategies in isoforms coming about as the alternative splicing result. Designed oligonucleotide probes and primers allow to distinguish mRNA isoforms of ER-alpha and their quantification in assessed tissues.

Genetic disregulation of gene coding tumor necrosis factor alpha receptors (TNF alpha Rs) in follicular thyroid cancer--preliminary report

TNF alpha receptors participate in programmed cell death. TNF R2 efficiently assists TNF R7 effects by ligand passing. Structure of TNF alpha receptors influences TNF activity in vivo and the structure of TNF R2 gene may suggest post-transcription modification based on alternative splicing. The aim of the study was to analyse the expression of gene coding TNF alpha receptors R2 and R7 by estimation of mRNA expression of differentiated thyroid carcinomas in comparison to surrounding tissue free from neoplastic infiltration and search for differently spliced TNF alpha R2/R7 isophorms. The study included seven patients with histopathologically confirmed follicular thyroid cancer. Tissue samples removed from tumor region were obtained from the follicular thyroid cancer patients undergoing surgical treatment. The samples were divided into two parts. The first one was routinely examined histopathologically, the second was used for RNA extraction and the number of TNF and its receptors mRNA copies were subsequently quantified.

RESULTS

1) The presence of TNF alpha expression was observed in all examined samples, in contrast to TNF R1 expression; 2) The high level of TNF alpha expression was noted both for typical and sought TNF R2/R7 isoforms and 3) A considerable number of samples displayed higher levels of TNF R2 isoforms than TNF R2/R7 mRNA expression. Genetic disregulation observed in neoplastic disease usually concerns dysfunction of cytokines receptor genes.

[Histone H3 gene expression level as markers of hyperplasia simplex of endometrium]

SUBJECT

The excessive proliferative activity of endometrial cells drives to hyperplasia, via states: simplex hyperplasia, complex and atypical hyperplasia, and finally preneoplastic state may arise. New molecular markers and their ability to differentiate physiological and pathological states are described.

DESIGN

The aim of this study was to evaluate the usefulness of histone H3 gene expression level as a marker of hyperplasia of endometrium.

MATERIAL AND METHODS

The level of H3 mRNA was estimated using RT-QPCR method in proliferative phase (n = 5) and endometrial hyperplasia simplex (n = 8). Differences in expression level of H3, were evaluated by Student's t-test (t-test for independent samples).

RESULTS

In our experiments the average mRNA H3 expression was significantly higher(p < 0.05, p = 0.03) in case of hyperplasia simplex in comparison to H3 expression in proliferative state of endometrium.

CONCLUSION

The results confirm advantage of estimation of H3 mRNA level as a marker of cell proliferation in endometrium.

[Quantitative (RT-QPCR) analysis of telomerase subunit in normal endometrial tissues]

Telomerase is a specialized ribonucleoprotein polymerase that elongates telomeres. To clarify the molecular mechanisms through which telomerase is activated in normal endometrium, we examined the expression profiles of each telomerase subunit in this tissues. A total of 22 normal human endometrium in various menstrual phases were examined for the expression of each telomerase subunit (hTERT, hTR, TP-1) using RT-QPCR. The hTERT as well as TP-1 subunit had higher expression levels in proliferative than secretory phase endometrium. Expression levels of hTR did not change during menstrual cycle. Our data showed the strong correlation between the level of expression of telomerase in human endometrium and phase of menstrual cycle.

Susceptibility to antibiotics and biochemical properties of Desulfovibrio desulfuricans strains

Susceptibility to several antibiotics and biochemical properties of intestinal and soil strains of Desulfovibrio desulfuricans bacteria were investigated using the tests: ATB ANA, Sceptor Anaerobic MIC/ID and API ZYM. It was demonstrated that the D. desulfuricans strains were resistant to penicillin, cefoxitin, clindamycin, metronidazole, erythromycin, rifampicin and teicoplanin. The strains initially susceptible to imipenem became resistant to this drug following 72 h incubation with it. Of 25 analyzed antibiotics there was none that after 72 h action on the bacteria was effective in relation to all of the investigated strains. The differences in susceptibility of D. desulfuricans strains to antibiotics were not associated with the strains' biochemical properties.

[The assessment of expression of kininogen and bradykinin receptors genes in different vulvar pathologies by QPCR (TaqMan)]

OBJECTIVES

In different vulvar pathologies inflammatory process and pain are often observed. In these processes, kinins, released from kininogen, play an important role. Their effects are mediated by at least two types of bradykinin receptors--B1 and B2. B1 receptor appears in certain pathological states, B2 is widely distributed in normal tissues. The expression of genes coding kininogen, B1 and B2 receptors can be a very sensitive marker of tissue pathology.

DESIGN

In the present study, the analysis of expression of genes coding kininogen, B1 and B2 was performed. The relation between the analysed genes expression and the pathology stage was analysed.

MATERIALS AND METHODS

The specimens from condylomata accuminata, vulvar cancer and surgical margin were analysed. The number of DNA and mRNA copies of beta-actine, kininogen, B1 and B2 were examined basing on Q-PCR standard curves for beta-actine by use of Perkin Elmer-kit and the sequence detector ABI PRISM 7700-Taq Man application.

RESULTS

In condylomata accuminata the high expression of mRNA of kininogen, B1 and B2 was found, while in vulvar cancer tissue, the expression of analysed genes was low. In the tissue from the tumour center, the lowest kinin genes expression was stated.

CONCLUSIONS

The absence of kininogen and B2 mRNA expression characterised vulvar cancer tissue. The profile of expression of kininogen and its receptor genes can be a useful marker in the assessment of vulvar cancer surgical margin.

[The quantitative analysis of E6 HPV and P53 genes expression by QPCR (TaqMan) in the assessment of surgical treatment range in vulvar carcinoma induced by HTV infection]

OBJECTIVES

Human Papilloma Virus (HPV) infections especially 16 and 18 are risk factors for squamous cell vulvar cancer. E6 protein of HPV joins the tumor suppressor protein P53 and promotes its degradation. This is one of the possible mechanisms of viral oncogenes action.

DESIGN

In this study the quantitative analysis of mRNA copies E6 HPV 18 and mRNA P53 expression in vulvar cancer tissue was performed. The expression of analysed genes was applied in the assessment of surgical treatment range.

MATERIALS AND METHODS

The specimens from a 26 year old woman with vulvar squamous cell cancer stage II FIGO treated surgically modo Way were analysed. The number of DNA and mRNA copies E6 HPV and P53 were examined basing on Q-PCR standard curves for beta-actine by use of Perkin Elmer-kit and the sequence detector ABI PRISM 7700-Taq Man application.

RESULTS

The overexpression of mRNA E6 HPV and P53 in analysed specimens was found. The highest number of mRNA copies in cancer tissue was ascertained. In lichen sclerosus and lymphonoduli tissue lower number of analysed copies was found.

CONCLUSION

The quantitative analysis of E6 HPV and P53 genes expression can be useful in the assessment of surgical treatment range in vulvar cancer and can also be used as a prognostic marker.

METOPROLOL EFFECT ON FATTY ACIDS COMPOSITION OF CELL MEMBRANE PHOSPHOLIPIDS

It is quite well known that β-blockers influence the stability of cell membranes, but the effect of metoprolol on the composition of cell membrane lipids is not established. On the other hand, synchronous culture of Chlorella vulgaris cells, which consists of cells brought to the same developmental stage by cycling lighting, provides a convenient biological model in unidirectional analyses aimed at assessment of effects of xenobiotics on cells. Advantages of the model include short life cycle and possibility to control metabolic processes of the cells across the broad range. We assessed the effect of metoprolol on fatty acids composition of cell membrane phospholipids in consecutive life cycle stages of Chlorella vulgaris. Lipids were extracted using a chlorofonn/methanol method. Phospholipids were precipitated from the chloroform phase with cold acetone and following centrifugation the pellet of phospholipids was hydrolyzed in alkaline solution. Fatty acids were extracted with petroleum ether and then methylated with BF3-methanol. This protocol produced methyl esters of fatty acids which were subjected to GC-MS analysis. Metoprolol had no effect on the number of progeny cells of Chlorella vulgaris throughout their life cycle at the concentration range tested (5x10-5 M, 5x10-6 M, 5x10-7 M). However, we observed stimulation of biological activity of Chlorclla cells as measured by spectrophotomctry at λ=680 nm. Metoprolol, at the highest concentration, increased phospholipids content in mother cells. Simultaneously, relative amount and saturation level of thc fatty acids remained constant.

Short-term changes of serum IL-2 and IL-6 induced by interferon alpha-2b in patients with chronic hepatitis C

BACKGROUND

The standard therapy of chronic hepatitis C with interferon alpha (IFN alpha) and ribavirin has established but limited efficacy. The prognostic factors of treatment are still under investigation. IL-2 and IL-6 are key cytokines involved in activation of B and T lymphocytes and thus in humoral and cellular responses; they are also deeply involved in generation and maintenance of inflammatory processes. The aim of the study was to evaluate the short-term influence of INF alpha-2b on serum IL-2 and IL-6 levels in sustained responders (SR) and non-responders (NR).

MATERIAL AND METHODS

Altogether 12 patients (7 males and 5 females) chronically infected with HCV (anti-HCV positive, HCV-RNA positive by PCR) were enrolled to the study. Patients were treated with IFN 3 MU tiw for 6 months and then they were followed for another 6 months. Five patients responded to the treatment (sustained responders-SR)-Group I, seven patients did not respond (non-responders-NR)-Group II. Serum concentrations of IL-2 and IL-6 were assessed by ELISA before ['0'] and at 1st ['1'], 2nd ['2'], 3rd ['3'], 6th ['4'] and 12th ['5'] hour after the first IFN injection.

CONCLUSIONS

Interferon alpha-2b induced short-term increase of serum IL-2 concentrations in SR but not in NR. Serum IL-6 level increased both in SR and NR but this effect was more pronounced and persisted longer in sustained responders.

Increased AST and GGT activity as marker of RT-PCR inhibition in RNA extracts from peripheral blood

The presence of HCV RNA in PMBC, with simultaneous absence of the virus in the plasma (7.8%), suggests that blood is better material for HCV RNA detection than plasma or serum in the diagnostic procedures of patients with chronic hepatitis C as well as in monitoring the antiviral therapy. We studied 111 patients with chronic hepatitis C (anti-HCV+) and elevated level of at least one biochemical marker: AST, ALAT, GGT, AP and bilirubin. Inhibition of amplification was 2% in plasma and 34% in whole blood samples. We applied modification of extraction to reduce the inhibitory effect on PCR, by introducing additional purification of the RNA extract in the Chomczyński method. After our modification of extraction was applied, inhibition was reduced to 1%. In attempt to identify such inhibitory markers that would label the samples, in which additional RNA extract purification should be applied, we analysed the activity of AST and ALAT enzymes, the key markers for parenchymal liver damage; GGT and AP, the markers for cholestatic hepatitis as well as bilirubin. We observed that the increased GGT and AST activities were correlated with the inhibition of RT-PCR. This correlation was statistically significant; for AST (Mann-Whitney test p = 0.09654 and Kolmogorow-Smirnow test p = 0.01543) and for GGT (Mann-Whitney test p = 0.02419 and Kolmogorow-Smirnow test p = 0.01921).

Interferon versus interferon and UDCA combined therapy in chronic hepatitis C

BACKGROUND

Interferon alpha (IFN) has been shown to have established efficacy in the treatment of chronic hepatitis C but its effectiveness is unsatisfactory. Combined therapies with IFN and other antiviral or immunomodulatory drugs are under evaluation. A combination of interferon alpha and ursodeoxycholic acid UDCA has been reported to give better results than interferon alone. The aim of the study was to assess the efficacy of IFN monotherapy versus IFN and UDCA therapy in patients with chronic hepatitis C.

MATERIAL AND METHODS

We studied 38 patients (25 males and 13 females) chronically infected with HCV (anti-HCV positive, HCV-RNA positive by PCR). Seventeen of them were treated with IFN 3 MU tiw for 6 months--Group I. The remaining 21 patients were treated with IFN, at the same dosage, plus UDCA (10 mg/kg/day) also for 6 months--Group II. Patients were followed for 6 months. 6 months after the end of therapy, laboratory biochemical parameters, HCV viremia and proportion as well as time to relapse were assessed.

CONCLUSIONS

In contrast to previous reports we did not find any differences neither in proportion of HCV reactivation nor in the time of its appearance among patients treated because of chronic hepatitis B with IFN alone or with IFN plus UDCA combined therapy. We also did not find any difference in initial and late response to the treatments in both groups.

Assessment of HBV DNA levels in human plasma and peripheral blood mononuclear cells by TaqMan Q-PCR assay

Hepatitis B virus DNA (HBV DNA) levels were quantitatively determined by a TaqMan quantitative polymerase chain reaction (TaqMan Q-PCR) in the plasma and in the peripheral blood mononuclear cells (PBMCs) of 120 patients with biopsy proven chronic hepatitis. The number of HBV DNA copies ranged from 10(1) to 10(10)/ml of the blood. There were no significant differences between plasma and PBMCs levels of HBV DNA in neither of HBV infected alone nor HCV co-infected patients. The number of HBV DNA copies was higher in the both compartments in blood of patients infected with HBV only, in comparison to those co-infected with HBV and HCV. In patients chronic hepatitis caused by both viruses (co-infection), decrease of HBV DNA copies in the PBMCs preceded its disappearance from the plasma. Our results suggest that assessment of HBV DNA in PBMCs does not produce important advantage in diagnosis of chronic hepatitis, and it seems to have the prognostic significance of positive outcome among the patients with chronic hepatitis induced by HBV and HCV co-infection. Our results also indirectly indicate that HCV may reciprocally inhibit replication of HBV.

Dynamics of HCV replication in patients with chronic hepatitis C during interferon and ribavirin combined therapy

Objective of the present study was to determine the effect of combined therapy with interferon alfa-2b (3 MU; thrice weekly s.c.) and ribavirin (1200 mg daily p.o.) on the number of copies of positive and negative strands of the hepatitis C virus RNA (HCV RNA) in patients with biopsy-proven chronic hepatitis C. Number of copies of both strands was determined by a TaqMan reverse transcription quantitative polymerase chain reaction (TaqMan RT Q-PCR) in the whole blood before treatment, and 4, 12 or 24 weeks after introduction of the treatment. Before the treatment positive strand of HCV RNA was more frequently detectable and its level was higher compared to that of the negative strand. In several patients, we observed therapy-induced transient appearance or increase in the number of copies of the negative HCV RNA strand. As a result of 24-week treatment, the negative strand of HCV RNA was eliminated from the blood more effectively than the positive strand. Our results suggest that the assessment of dynamics of changes of the positive and negative strands levels of HCV RNA in interferon-naive patients with chronic hepatitis C may be useful in monitoring short-term effectiveness of combined antiviral therapy. They also indicate that TaqMan RT Q-PCR appears to be a valuable tool in monitoring the therapy in these patients.

[Expression of VEGF, KDR, p53, E6 HPV16 and HPV18 in vulvar and cervix cancer]

The aim of the study was a comparison of expression of angiogenesis genes: vascular endothelial growth factor (VEGF), KDR, suppressor gene p53, E6-HPV16 and HPV18, in tissue samples of normal, dystrophic, lymph nodes and malignant cancers of vulva and uterine cervix. The results demonstrate that molecular diagnostics of cancers using gene expression profiling indicates the definitive difference in expression profiles of aforementioned genes in tissues of the same malignancy.

[Profiles of expression of genes coding kininogen and kinin receptors as a marker of tissue pathology in cervical cancer coexisting with HPV infection]

Kinins are peptides involved in inflammatory processes, vascular permeability, proliferation and mitogenesis of tumor cells. The majority of kinins actions are mediated through an interaction with cell surface bradykinin receptors BR1 and BR2. Kinins precursor is kininogen (kng). The changes in proteins are initiated by changes in the expression of genes coding these proteins, thus can be a valuable diagnostic markers of malignant processes including cervical carcinoma. The paper presents an analysis of kininogen-kinins receptor genes expression in women treated surgically because of a carcinoma of uterine cervix. Among the studied women in 5 cases previously brachyHDR therapy was applied. In all studied cases HPV 18 infection and in 2 cases a co-infection HPV 16/18 by use of Consensus Primers MY09, MY 11 and type specific primers for HPV 16, 18 was ascertained. In RNA extracts the number of the mRNA copies for kiningen, BR1 and BR2 was assessed using QRT-PCR Taq Man. The higher expression of BR1 than BR2 was marked in the tissue with cancer cells. In the patients after brachytherapy higher expression of BR2 than BR1 mRNA was found. The higher BR1 expression was also shown in iliac lymph nodes in patients with active neoplastic process, opposite to the patients after brachytherapy in whom higher BR2 expression was ascertained. The lack of expression of kng mRNA was found only in 3 specimens. The high expression of kinin receptors especially BR1 in infiltrating carcinoma margin can be a marker of pathology intensity: proliferative potential of neoplasms cells or chronic inflammatory state in the presence of invasive carcinoma.

[Prenatal diagnostics of Toxoplasma gondii invasion by quantitative method of PCR-TaqMann]

Routine serological diagnosis of toxoplasmosis provides high sensitivity, but not high specificity. The high sensivity combined with high specifity offered by PCR-TaqMann as well as the degree of infection led us to investigate the presence and levels of T. gondii DNA in amniotic fluid, maternal and neonatal blood in cases of pregnancy where infection with this agent was suspected. Samples of amniotic fluid and blood were taken from pregnant women. Postnatal blood samples were also taken from their infants. Presence and levels of toxoplasma DNA was investigated using PCR-TaqMann. PCR products were detected by electrophoresis on polyacrylamide gel. The PCR-TaqMann test is highly sensitive, specific and useful method allowing detection of the parasite genome and assessement of its level.

Positive and negative strands of HCV-RNA in sera and peripheral blood mononuclear cells of chronically hemodialyzed patients

BACKGROUND

Hepatitis C virus (HCV) RNA can be detected in sera and peripheral blood mononuclear cells (PBMC) of patients undergoing chronic hemodialysis. However, the natural course of HCV infection in this group of patients is not fully known. Although the exact mechanism of HCV replication is not completely explained, there is evidence that HCV replicate through synthesis of complementary negative (-) RNA strand, whereas positive (+) RNA strand serves as a template. Thus, the detection of negative HCV-RNA strand can be regarded as a marker of ongoing viral replication.

MATERIAL AND METHODS

We investigated the prevalence of (+) and (-) strands of HCV-RNAs in sera and PBMC of 45 chronically hemodialyzed patients using PCR methods. We also determined HCV genotypes and their subtypes by Inno-LIPA method.

RESULTS

Eight (17.8%) of analyzed patients were anti-HCV positive. In this group, we detected HCV-RNA (+) strands in sera and PBMC in 2 and 4 cases respectively, whereas HCV-RNA (-) ones were found in PBMC of 4 patients. Among the remaining 37 anti-HCV negative patients we found HCV-RNA positive strands in sera and PBMC in 2 and 3 cases respectively, whereas HCV-RNA negative strand was present in PBMC in one of them.

CONCLUSIONS

Our results indicate that HCV actively replicate in PBMC in chronically hemodialyzed patients. In number of patients HCV-RNAs can be detected only in PBMC without concomitant presence of viremia or anti-HCV in sera. We did not find any correlation between genotypes of HCV and presence of HCV-RNAs strands in PBMC of the patients.

[Detection of Toxoplasma gondii DNA by PCR in mother's blood, amniotic fluid and child's blood in selected cases of pathological pregnancy]

Prenatal screening of Toxoplasma gondii infection is controversial. The diagnosis is based on serological tests detecting IgM and IgG antibodies against T. gondii, but interpretation of these tests results is often confusing. It is commonly made retrospectively when serological screening indicates a possibility of recent infection. Most women have antibodies against T. gondii and serial testing is required only in monitoring of pregnancies where initial screening is negative. The introduction of Polymerase Chain Reaction (PCR) assay for detection of Toxoplasma gondii DNA in selected cases of pathologic pregnancies has permitted a more accurate and faster diagnosis of congenital toxoplasmosis infections.

Peroxynitrite mediated linoleic acid oxidation and tyrosine nitration in the presence of synthetic neuromelanins

Peroxynitrite-mediated linoleic acid oxidation and tyrosine nitration were analysed in the presence of synthetic model neuromelanins: dopamine (DA) -melanin, cysteinyldopamine (CysDA) -melanin and various DA/CysDA copolymers. The presence of melanin significantly decreased the amount of 3-nitrotyrosine formed. This inhibitory effect depended on the type and concentration of melanin polymer. It was found that incorporation of CysDA-derived units into melanin attenuated its protective effect on tyrosine nitration induced by peroxynitrite. In the presence of bicarbonate, the melanins also inhibited 3-nitrotyrosine formation in a concentration dependent manner, although the extent of inhibition was lower than in the absence of bicarbonate. The tested melanins inhibited peroxynitrite-induced formation of linoleic acid hydroperoxides, both in the absence and in the presence of bicarbonate. In the presence of bicarbonate, among the oxidation products appeared 4-hydroxynonenal (HNE). CysDA-melanin inhibited the formation of HNE, while DA-melanin did not affect the aldehyde level. The results of the presented study suggest that neuromelanin can act as a natural scavenger of peroxynitrite.

Normal colonocytes in primary culture--an experimental model for molecular pharmacology and biology of large intestine

A simple method of whole intestinal crypts isolation from rat's colonic tissue has been developed. Culture of viable epithelial cells (colonocytes) was obtained from intact crypts using method providing colonocytes for apoptosis. Satisfactory results have been obtained if the crypts were isolated using collagenase I. Under conditions applied, spontaneous release of the colonocytes took place. Liberated cells underwent almost immediate adhesion to microcarrier surface. The primary culture of normal colonocytes indicating metabolic activity for long time (> 10 days) has been obtained.