Immune thrombocytopenia: serum cytokine levels in children and adults

Background

Immune thrombocytopenia (ITP) is an immune-mediated platelet disorder in which autoantibody-coated platelets are removed from the blood by monocytic phagocytes and there is impaired platelet production. There is a delicate balance of specific cytokine levels, which has an important role in the immune system and is known to be deregulated in autoimmune diseases. This study was designed to investigate the differences in Th cytokine levels between children and adults with newly diagnosed ITP and to compare these profiles to those found in healthy, age-matched controls.

Material/Methods

The concentration of IL-1α, IL-2, IL-3, IL-4, IL-6, IL-10, TNF-α, IFN-α, and IFN-γ in serum specimens was analyzed by enzyme-linked immunosorbent assay.

Results

At the time of ITP diagnosis, children showed significantly lower serum levels of interleukin IL-2 and tumor necrosis factor TNF-α and higher serum level of IL-3 than healthy controls. Serum level of IL-4 in adult ITP patients was higher than those in control subjects. When compared with adults, children with ITP had lower serum level of IL-4, IL-6 and IFN-γ, and higher level of IFN-α.

Conclusions

Significant differences in serum cytokine levels between pediatric patients and healthy controls indicate that cytokine disturbances – especially changes in IL-2, IL-3 and TNF-α – might be involved in the pathogenesis of newly diagnosed ITP. TNF-α is the most informative variable for discrimination between healthy children and those with ITP.

Immune thrombocytopenia: serum cytokine levels in children and adults

BACKGROUND

Immune thrombocytopenia (ITP) is an immune-mediated platelet disorder in which autoantibody-coated platelets are removed from the blood by monocytic phagocytes and there is impaired platelet production. There is a delicate balance of specific cytokine levels, which has an important role in the immune system and is known to be deregulated in autoimmune diseases. This study was designed to investigate the differences in Th cytokine levels between children and adults with newly diagnosed ITP and to compare these profiles to those found in healthy, age-matched controls.

MATERIAL/METHODS

The concentration of IL-1alpha, IL-2, IL-3, IL-4, IL-6, IL-10, TNF-alpha, IFN-alpha, and IFN-alpha in serum specimens was analyzed by enzyme-linked immunosorbent assay.

RESULTS

At the time of ITP diagnosis, children showed significantly lower serum levels of interleukin IL-2 and tumor necrosis factor TNF-alpha and higher serum level of IL-3 than healthy controls. Serum level of IL-4 in adult ITP patients was higher than those in control subjects. When compared with adults, children with ITP had lower serum level of IL-4, IL-6 and IFN-alpha, and higher level of IFN-alpha.

CONCLUSIONS

Significant differences in serum cytokine levels between pediatric patients and healthy controls indicate that cytokine disturbances--especially changes in IL-2, IL-3 and TNF-alpha--might be involved in the pathogenesis of newly diagnosed ITP. TNF-alpha is the most informative variable for discrimination between healthy children and those with ITP.

Heterozygous carriage of a dysfunctional Toll-like receptor 9 allele affects CpG oligonucleotide responses in B cells

Toll-like receptors (TLR) are employed by the innate immune system to detect microbial pathogens based on conserved microbial pathogen molecules. For example, TLR9 is a receptor for CpG-containing microbial DNA, and its activation results in the production of cytokines and type I interferons from human B cells and plasmacytoid dendritic cells, respectively. Both are required for mounting an efficient antibacterial or antiviral immune response. These effects are mimicked by synthetic CpG oligodeoxynucleotides (ODN). Although several hyporesponsive TLR9 variants have been reported, their functional relevance in human primary cells has not been addressed. Here we report a novel TLR9 allele, R892W, which is hyporesponsive to CpG ODN and acts as a dominant-negative in a cellular model system. The R892W variant is characterized by increased MyD88 binding and defective co-localization with CpG ODN. Whereas primary plasmacytoid dendritic cells isolated from a heterozygous R892W carrier responded normally to CpG by interferon-α production, carrier B cells showed impaired IL-6 and IL-10 production. This suggests that heterozygous carriage of a hyporesponsive TLR9 allele is not associated with complete loss of TLR9 function but that TLR9 signals elicited in different cell types are regulated differently in human primary cells.

Antitumor activity from the combined application of poly(I:C) and chemotherapeutics in human metastatic pharyngeal cell lines

BACKGROUND

Toll-like receptor 3 (TLR3) activation in tumor cells induces apoptosis. We investigated the effect of TLR3 ligand (poly(I:C)) in combination with chemotherapeutics applied to human pharyngeal carcinoma cells as a possible antitumor therapy.

METHODS

Human pharyngeal cancer cell lines were studied (FaDu and Detroit 562). Cytotoxicity assays and apoptosis assays (annexin V staining and caspase 3/7 activity measurements) were used to investigate the cytotoxic effects. By using TLR3 siRNA we confirmed that the observed effect is TLR3-dependent.

RESULTS

We found that the combined application of poly(I:C) and chemotherapeutics (cisPt, HU, 5-FU and MTX) has a stronger inhibitory effect on cell growth in tumor cells expressing functional TLR3 as compared with a single treatment. This is a result of TLR3-dependent apoptosis.

CONCLUSION

Our study showed that a combined application of the two agents already being used in tumor therapy could lower the necessary dosage of chemotherapeutics, leading to fewer side effects.

The ophthalmic anomalies in children with Down syndrome in Split-Dalmatian County

Our aim was to present the ophthalmic anomalies in patients with Down syndrome in Split-Dalmatia County born from 1992 until 2009 year. It was a cross-sectional study. 153 children with Down syndrome aged 0-18 years from the Split-Dalmatia County were examined. One hundred twelve participants were borne in Split, 13 in Vrgorac,16 in Makarska, 12 in Sinj. All enrolled children underwent a complete ophthalmological examination (anterior segment, ocular motility, refractive status, fundus, measuring intraocular pressure (IOP). Of 89.5% percent of responders with refractive errors, 48.1% had myopia, 35.0% had hypermetropia, astygamtism in 16.7%, 28.7% strabismus, nystagmus (8.4%), cataracts (1.3%), glaucoma (1.9%), supernumerary optic disc vessels (24.1%) and keratoconus (1.3%).

CONCLUSION

In patients with Down syndrome the prevalence of refractive errors (myopia prevalence), as well as other ophthalmological diseases was determined.

Full trisomy 5 in a sample of spontaneous abortion and Arias Stella reaction

BACKGROUND

Historically, 50% of spontaneously expelled abortuses have been thought to be chromosomally abnormal; about 60% are trisomies. In general, trisomy 16 is the most frequent chromosomal abnormality, followed by trisomy 21 and trisomy 22. So far only 1 case of a female fetus with multiple congenital malformations associated with full trisomy 5 has been described.

REPORT

We present a case of de novo full trisomy 5 in a spontaneous abortion sample. A young couple with normal constitutional karyotype experienced the second spontaneous abortion at 9 weeks of gestation, with the cytogenetic formula 47,XX,+5 in all analyzed cells.

CONCLUSIONS

The routine cytogenetic analysis of miscarriages is still an uncommon practice, but it can have a great impact on the management of couples with repeated pregnancy wastage. Besides of the obvious cost benefit for health care, such analysis would help the physician to decide about future patient management, as well as planning the genetic counseling.

Common acute lymphoblastic leukemia Ph+ following Langerhans cell histiocytosis in a multi-malformed child with INV (9) (p12;q13) (mat): case report

The occurrence of Langerhans cell histiocytosis (LCH) and another malignancy in the same patient is infrequent but has been recognized. The genetic changes that could be responsible for LCH and/or concomitant leukemia development are obscure. To the best of our knowledge, this is the first description of constitutional maternally derived inv (9) (p12;q13) in an LCH patient, and also of the development of common ALL Ph after LCH diagnosis and therapy. The potential significance of these findings [inv (9)+LCH+ALL Ph+] and their mutual relationship are unknown. Therefore, cooperative studies of large numbers of patients are needed to identify the common risk factors, if any.

Single-nucleotide polymorphisms in genes encoding toll-like receptor -2, -3, -4, and -9 in case-control study with breast cancer

BACKGROUND

Genetic susceptibility to cancer is multifactorial, and it is known that impairment of the immune system could contribute to risk for getting cancer.

AIM OF THE STUDY

Single-nucleotide polymorphisms (SNPs) of Toll-like receptor (TLR) 2, TLR3, TLR4, and TLR9 genes, which are important for innate immunity, were analyzed for the association with breast cancer.

METHODS

The SNPs comprised TLR2 (c.597T>C), TLR2 (c.1350T>C), TLR3 (c.1377C>T), TLR4 (c.896A>G), and TLR9 (c.1635A>G). The allelic and genotypic frequencies of these TLR SNPs were compared between patients (n = 130) and controls (n = 101) in a case-control study from Croatia.

RESULTS

TLR SNPs were not significantly different. From the population genetics viewpoint, we found that a hypomorphic variant of TLR4 (p.Asp299Gly) allele has no specific allelic frequency (8.4%) in the Croatian population (n = 496) compared to other Caucasians (6.5-10%).

CONCLUSION

These results suggest that polymorphisms in tested TLR genes are not likely to be associated with increased risk for developing breast cancer.

Fetal macrosomia in pregnant women with gestational diabetes

The aim of the study was to determine the frequency of fetal macrosomia in newborns from mothers with gestational diabetes mellitus (GDM) and healthy mothers, as well as determining the influence of fetal growth on pregnancy termination, on complications in pregnancy, during delivery and puerperium and on neonatal complications. In the study were included 351 pregnant women with GDM, as well as control group of 1502 healthy pregnant women. Newborns of mothers with GDM had significantly higher birth weight and length, ponderal index > 2.85 was more frequent, they were macrosomic and hypertrophic (disproportional and proportional), had smaller Apgar score and more frequent neonatal complications (p < 0.05). Fetal macrosomia and fetal hypertrophy alone or, particularly, connected with disproportional fetal growth, but disproportional hypotrophy as well, had significantly influence on greater frequency of delivery and puerperal complications, delivery completion with Cesarean section and neonatal complications in pregnant women with GDM.

Nm23-H1 promotes adhesion of CAL 27 cells in vitro

nm23-H1 was found to diminish metastatic potential of carcinoma cell lines and therefore was placed in the group of metastatic suppressor genes. Its protein product has a function of a nucleoside diphosphate kinase (NDPK) as well as protein kinase and nuclease. Though it was found that Nm23-H1 is involved in many cellular processes, it is still not known how it promotes metastatic suppressor activity. Since the process of metastasis is dependent on adhesion properties of cells, the goal of our work was to describe the adhesion properties of CAL 27 cells (oral squamous cell carcinoma of the tongue) overexpressing FLAG/nm23-H1. In our experiments, cells overexpressing nm23-H1 show reduced migratory and invasive potential. Additionally, cells overexpressing nm23-H1 adhere stronger on substrates (collagen IV and fibronectin) and show more spread morphology than the control cells. Results obtained by EGF induction of migration revealed that the adhesion strength predetermined cell response to chemoattractant and that Nm23-H1, in this cell type, does not interfere with, EGF induced, Ras signaling pathway. These data contribute to the overall knowledge about nm23-H1 and its role in cell adhesion, migration, and invasion, especially in oral squamous cell carcinoma.

Preoperative clonidine or levobupivacaine--effect on systemic inflammatory stress response

With perioperative pain control it is possible to supervise immune system, release of inflammation mediators, and influence on treatment outcome. Use of analgetics before the pain stimulus (preventive analgesia) obstruct development of neuroplastic changes in central nervous system, and reduces pain. Investigation hypothesis was that preoperative epidural clonidine is more efficient in blockade of systemic inflammatory stress response comparing to levobupivacaine. Patients were allocated to three groups, according to preoperative epidural use of clonidine, levobupivacaine or saline (control group). Before operation, 1 h after the beginning, 1 h, 6 h, 12 h and 24 h after the operation following parameters were analyzed: interleukine-6, C-reactive protein and leukocyte count. There were no significant differences between groups in age, gender, body mass index and operation time. In preoperative clonidine group, we found significant reduction in interleukine-6 levels throughout investigation time, compared to preoperative levobupivacaine group and control group. Also, C-reactive protein was significantly lower at the end of investigation, compared to other two groups. Leukocyte count was lower, and within the normal range in all investigation times only in preoperative clonidine group. We demonstrated significant difference that support importance of clonidine central effect on pain pathways and systemic inflammatory blockade.

Genitourinary diseases prior spontaneous abortion as a risk factor for recurrent pregnancy loss

The etiology of recurrent spontaneous abortion (RSA) is still unexplained. Many couples do not find the cause of their RSA at all. The purpose of this research was to evaluate the association between recurrent pregnancy loss and previous (cured prior to pregnancy) acute/chronic genitourinary infections in both parents. Couples (226) having two or more (up to six) spontaneous abortions were analyzed in this retrospective case-control study. The control group consisted of 124 couples with neither miscarriages nor complicated pregnancies in their past. The data (serum immunological markers, karyotype, flow cytometry data, PHD) were collected from their medical charts. It was found that there was no statistically significant difference in average weeks of pregnancy in which the second, third and fourth abortion occurred. There was a statistically significant difference in previously experienced genitourinary infections between women from the RSA group and the control group, as well as for men from the RSA group and the control group. It can be concluded that past infections of the maternal and/or paternal genitourinary system may be the causal factor for recurrent pregnancy loss and can also pre-determine women that are of greater susceptibility to preterm pregnancy. Therefore the genetic counseling of couples should include thorough medical and family history of both partners and their first- and second-degree relatives in conjunction with typical medical examination.

De novo NEMO gene deletion (delta4-10)--a cause of incontinentia pigmenti in a female infant: a case report

Incontinentia pigmenti (IP) is a rare, inherited, multisystem genodermatosis. It is transmitted as an X-linked dominant trait. The disorder is a consequence of mutations in the NEMO gene (Xq28) that completely abolish expression of the NF-kappaB essential modulator. Here we present a female infant of healthy nonconsanguinous, young parents with a clinically evident first phase of IP. PCR analysis of patient's peripheral blood lymphocytes DNA was done for detection of NEMO delta4-10 deletion. Skin changes present at birth appertain to first inflammatory stage. However, a pathohistological feature of the skin biopsy showed second phase of disease. Genetic testing of diseased child revealed delta4-10 in NEMO gene. However, the assumption that the female child has familial IP was rejected as PCR performed on the mother's leukocytes did not record the presence of the same mutation. Moreover, the existence of a healthy male infant of the same mother as well as the lack of any phenotypic signs of the disease in other family members additionally support that IP was not inherited, but it was a consequence of de novo NEMO gene mutation. In conclusion, here we describe a Croatian female with clinical IP phenotype having de novo genomic rearrangements in the NEMO gene.

Gene expression profiling of Nm23-H2 overexpressing CAL 27 cells using DNA microarray

Nm23-H1/NDPKA and Nm23-H2/NDPKB belong to a large family of NDP kinases, group of structurally and functionally closely related enzymes. The Nm23/NDPs are known to catalyse the transfer of terminal phosphates from ATP to other NTPs and dNTPs. Besides their role in the maintenance of the cells NTP pool the nm23 genes/proteins are known to have additional different biological functions, the most important being its metastasis suppressor activity. The complete picture of roles, actions and targets of nm23 genes/proteins is yet to be discovered. Our goal was to identify the downstream targets of Nm23-H2 by subjecting Nm23-H2 overexpressing CAL 27 cells (oral squamous cell carcinoma of the tongue) to microarray analysis. Using this powerful technology we identified genes, groups of genes and signalling pathways that could be clustered into several groups: apoptosis related genes, cell cycle and DNA damage, TGFbeta (transforming growth factor beta) signalling pathway and related molecules, WNT signalling pathway, differentiation and epithelial structural and related molecules, cell adhesion, metalloproteinases and their inhibitors, vesicular transport related molecules, proteasome associated, ubiquitin mediated proteolysis and several metabolic pathways. Based on these results we suggest that nm23-H2 might have an important role in oral squamous cell carcinoma which is to be confirmed by future studies.

Analysis of cystic fibrosis gene mutations and associated haplotypes in the Croatian population

The aim of this study was to reveal the CFTR gene mutation status in the Croatian population as well as to establish the haplotypes associated with cystic fibrosis (CF) and those associated with specific gene mutations. A total of 48 unrelated CF patients from Croatia were examined. Among 96 tested alleles, we found nine different mutations: DeltaF508, 58.33%; G542X, 3.12%; N1303K, 2.08%; R1162X; 621 + 1G --> T; G85E; Y569C; E585X; and S466X, 1.04%. Analysis of three polymorphic loci revealed 15 different haplotypes. Two of them (21-23-13 and 21-17-13) occurred with a higher frequency (40% and 24%). Both of these haplotypes also carried a CFTR gene mutation (DeltaF508 or G542X) on 27 out of 32 chromosomes. Among 12 (of all together 29) CF alleles on which no mutations were found, we detected 10 different haplotypes. Because there are still no published data on the distribution of polymorphic loci in Croatia, nor haplotypes associated with mutations in the CFTR gene, our results greatly contribute to knowledge regarding the genetic background of CF in this region.

Insulin-like growth factor 2 and its receptors (IGF 1R and IGF 2R/mannose 6-phosphate) in endometrial adenocarcinoma

OBJECTIVE

To investigate the consequences of IGF proteins dysfunction in development of endometrial adenocarcinomas.

METHODS

The expression of IGF 2 and IGF 1R was correlated with the expression of IGF 2R and apoptosis rate in 59 human endometrial adenocarcinomas, 10 endometrial hyperplasias and 7 normal tissues. The presence of mutations in the IGF 2R gene was followed in 46 adenocarcinomas. We also examined the effect of IGF 1 receptor blockage on cancer cell proliferation. In groups of either IGF 2-positive or IGF 2-negative tumors (stages III and IV) the expression of IGF 1 and IGF 1R was correlated with cell proliferation index and telomerase activity.

RESULTS

The expression of IGF 2 and IGF 1R was much higher in malignant tissue of stages III and IV than in tumors of stages I and II and normal or hyperplastic endometrium. This correlated with a decreased apoptosis rate and IGF 2R expression. Eight adenocarcinomas expressed biallelic mutation of the IGF 2R gene. The specific inhibition of IGF 1R and IGF 2 decreased tumor cell proliferation in IGF 2/IGF 1R-positive tumors. Furthermore, the positive correlation between increased expression of IGF 1 and IGF 1R proteins and increased telomerase activity and cell proliferation index was found in both IGF 2-negative and IGF 2-positive tumors.

CONCLUSION

Our data suggest that IGF 1, IGF 2 and their receptors are involved in the progression of endometrial adenocarcinomas. As cancer cell proliferation can be abrogated by blocking mRNA or protein products of these genes, tumors with extensive involvement of the IGF 2 pathway would be candidates for the therapeutics strategies aimed at interference with this pathway.

Biological & physiological aspects of action of insulin-like growth factor peptide family

The insulin-like growth factor (IGF) is a complex system of peptide hormones (insulin-like growth factors of type 1 and 2, IGF-1 and IGF-2), cell surface receptors (insulin receptor, IR; insulin-like growth factor receptors of type 1 and 2, IGF-R1, IGF-R2) and circulating binding proteins (insulinlike growth factor binding proteins, IGF-BP 1-6). IGF-1 and -2 are mitogens that play a role in regulating cell proliferation, differentiation and apoptosis. Their effects are mediated through the IGF-R1 which initiates signaling cascades that result in regulation of a number of biological responses. IGF-R2, together with IGF-BPs is involved in binding, internalization and degradation of IGF-2. IGF proteins regulate cell proliferation in an interconnected action via autocrine, paracrine and endocrine regulatory mechanisms. Consequently, any perturbation in each level of the IGF signaling proteins has been shown to be implicated in development and progression of numerous cancer types. The most important single components in this processes are IGF ligands as well as IGF-R1 - when disturbed they act as oncogenes. It has been shown that: (i) high serum concentrations of IGF-1 and IGF-2 are associated with an increased risk of breast, prostate, colorectal and lung cancers; and (ii) IGF-R1 is commonly disturbed in many tumours (like gastric, lung, endometrial cancer) leading to a phenotype of anchorage-independent tumour growth. In contrast, IGF-R2 is considered to act as a tumour suppressor gene; it protects the cells from neoplastic impulses. Consistent with the IGFs autocrine/paracrine regulation of tumour growth, cancer treatment strategies interfering with IGF-R1 signaling have been developed, that may be useful in future diagnostic and therapeutic strategies.

The MECP2 gene mutation screening in Rett syndrome patients from Croatia

Rett syndrome (RTT) is an X-linked dominant neurodevelopmental disorder almost exclusively affecting females and is usually sporadic. Mutations in MECP2 gene have been found in more than 80% of females with typical features of RTT. In this study, we analyzed 15 sporadic cases of RTT. In 7 of 15 patients (47%), we detected pathogenic mutations in the coding parts of MECP2 fourth exon. We found two missense (T158M, R133C), two nonsense (R168X, R270X), two frameshift mutations (P217fs and a double deletion of 28-bp at 1132-1159 and 10-bp at 1167-1176), and one in-frame deletion (L383_E392del10). To our knowledge, the last two mutations have not been reported yet. We also detected one previously described polymorphism (S194S). In conclusion, these results show that the fourth exon should be the first one analyzed because it harbors most of the known mutations. Moreover, mutation-negative cases should be further analyzed for gross rearrangements. This is the first study of its kind in Croatia and it enabled us to give the patients an early confirmation of RTT diagnosis.

Downstream targets of Nm23-H1: gene expression profiling of CAL 27 cells using DNA microarray

The human nm23-H1 was discovered as a tumor metastasis suppressor based on its reduced expression in melanoma cell lines with low versus high metastatic potential. It encodes for one of two subunits of the nucleoside-diphosphate kinase. Besides its role in the maintenance of the cells NTP pool, nm23 plays a key role in different cellular processes. The role of nm23-H1 in these processes still has to be elucidated. Our goal was to identify Nm23-H1 downstream targets by subjecting Nm23-H1 overexpressing CAL 27 cells oral squamous cell carcinoma (OSSC) to microarray analysis. The genes with changed expression patterns could be clustered into several groups: transforming growth factor beta (TGFbeta) signaling pathway, cell adhesion, invasion and motility, proteasome machinery, cell-cycle, epithelial structural and related molecules and others. Based on the expression patterns observed we presume that nm23-H1 might have a role in OSSCs, which should be confirmed by future experiments.

Prevalence of the 35delG Mutation in theGJB2Gene of Patients with Nonsyndromic Hearing Loss from Croatia

The aim of this study was to investigate the allelic frequency of 35delG mutation in patients with recessive, nonsyndromic hearing loss (NSHL) compared to normal hearing individuals in the Croatian population. For this purpose, we analyzed 27 unrelated individuals with nonsyndromic hearing loss and 342 healthy individuals. The method we used is based on the principle of polymerase chain reaction (PCR)-mediated, site-directed mutagenesis, followed by a BsiYI digestion. Among patients with NSHL, the 35delG mutation was found on 51.85% alleles. Carrier frequency among healthy control individuals was 1 in 68.4 (1.5%). The patients, found to be wild-type, either in heterozygous or homozygous form, were further tested by direct sequencing. Among them, two different mutations were observed, W24X and 313del14. Relatively high prevalence of 35delG mutation among patients with NSHL indicate that it is an important cause of NSHL in Croatia. Early diagnosis by identification of the 35delG mutation would greatly improve genetic counseling, as well as treatment and management of deafness in Croatia.

Subcellular localization of A and B Nm23/NDPK subunits

The human Nm23-H1/NDPK A and Nm23-H2/NDPK B encode for two subunits of nucleoside diphosphate kinase--a ubiquitous enzyme that transfers the terminal phosphates from ATP to (d)NDPs. Although having an 88% amino acid sequence identity and an already assigned biochemical role in the cell, the two subunits appear to have additional and distinctive cell functions. In particular, both subunits have been reported to be involved in tumor progression and metastasis. The aim of this study was to determine the specific, and potentially distinct, localizations of both subunits in tumor cells of different origin and differentiation and therefore to search for a possible link between their localization and the stage of disease. We used the GFP reporter system to analyze the ectopic expression of GFP-Nm23 proteins in head and neck tumor cell lines by fluorescent microscopy techniques. Our experiments revealed that GFP-fused Nm23-H1 and -H2 proteins display the same localization in transfected cells, regardless of their origin and differentiation status. The proteins are principally found in the cytosol and the endoplasmic reticulum. Moreover, some cells exhibit nuclear staining, which appears to be cell cycle-dependent.

Gastric cancer: the role of insulin-like growth factor 2 (IGF 2) and its receptors (IGF 1R and M6-P/IGF 2R)

Insulin-like growth factor 2 (IGF 2) appears to be involved in the progression of many tumours. It binds to at least two different types of receptor: IGF type 1 (IGF 1R) and mannose 6-phosphate/IGF type 2 (M6-P/IGF 2R). Ligand binding to IGF 1R provokes mitogenic and anti-apoptotic effects. M6-P/IGF 2R has a tumour suppressor function--it mediates IGF 2 degradation. Mutation of M6-P/IGF 2R causes both diminished growth suppression and augmented growth stimulation. The aim of this study was to investigate the role of IGF 2 and its receptors (IGF 1R and IGF 2R) in human gastric cancer. The expression of IGF 2 and its receptors was measured in order to analyse the possible correlation between the activity of these genes and cell proliferation in two different gastric tumour types: diffuse and intestinal. The effect of IGF 1 receptor blockage on cell proliferation and anchorage-independent cell growth was also examined. Increased expression of IGF 2 and IGF 1R genes (at the mRNA and protein level) was found in gastric cancer when compared with non-tumour tissue. Furthermore, there was a significant difference between IGF 2 expression in the more aggressive diffuse type and that in the intestinal type of gastric cancer. Moreover, the IGF 2 peptide level in the culture media obtained from the diffuse type of cancer cells was significantly higher when compared with the intestinal type. The level of IGF 2 peptide in the conditioned media strongly correlated with [3H]thymidine incorporation and cell proliferation. On the contrary, IGF 2R mRNA expression was much higher in the intestinal type of cancer than in the diffuse type. In addition, IGF 2R protein expression was substantially lower with progression of the diffuse cancer type to a higher stage. The alphaIR3 monoclonal antibody strongly inhibited [3H]thymidine incorporation and decreased the number of colonies in soft agar of cells overexpressing IGF 2. These findings suggest that members of the IGF family are involved in the pathogenesis of gastric cancer, probably by autocrine/paracrine stimulation of cell growth. Such tumours might be excellent candidates for therapeutic strategies aimed at interference with this pathway.

p21WAF1/CIP1 is more effective than p53 in growth suppression of mouse renal carcinoma cell line Renca in vitro and in vivo

PURPOSE

Although there are many controversial reports about the effect of p53 and p21(WAF1/CIP1) overexpression in different human tumor cells, the p53 gene is shown to be a more effective candidate for cancer gene therapy because of its more pronounced ability to induce apoptosis. In the present study, we present the effect of p53 and p21(WAF1/CIP1) overexpression on mouse renal carcinoma cells in vitro and in vivo.

METHODS

p53 and p21(WAF1/CIP1) genes were introduced into Renca cells using adenoviral vectors (Ad5CMV-p53 and Ad5CMV-p21). The induction of apoptosis was measured using Annexin V assay and DNA fragmentation analysis. The expression of proteins was examined using immunocytochemistry and Western blot methods. The ability of adenoviral vectors to inhibit tumorigenicity of Renca cells, as well as the growth of pre-established tumors was measured.

RESULTS

In vitro growth assays revealed higher growth suppression after Ad5CMV-p21 infection. Although both vectors induced apoptosis, Ad5CMV-p53 was slightly more efficient. In vivo studies in Balb/c mice, demonstrated that tumorigenicity was completely suppressed by Ad5CMV-p21. Besides this, Ad5CMV-p21 significantly inhibited the growth of established tumors, while Ad5CMV-p53 did not.

CONCLUSIONS

These data suggest that p21(WAF1/CIP1) is a more potent growth suppressor than p53 of mouse tumor cells Renca. The divergent responses of tumor cells to p21(WAF1/CIP1) overexpression could be due to various networks that differ between species.

Endogenous p21WAF1/CIP1 status predicts the response of human tumor cells to wild-type p53 and p21WAF1/CIP1 overexpression

Expression of exogenous wild-type (wt) p53 protein can suppress the growth and/or induce apoptosis in different tumor cells. The effect of exogenous p21(WAF1/CIP1) expression is more controversial: while it can induce apoptosis in some cells, it can protect against p53-mediated apoptosis in others. We used adenoviral vectors to introduce p53 and p21(WAF1/CIP1) genes into human tumor cell lines with different p53 and/or p21(WAF1/CIP1) status. The cell growth inhibition and the induction of apoptosis were measured. Overexpression of wt p53 induced more efficient growth inhibition and apoptosis in SW 620 (mutant p53) and HeLa (inactivated p53 protein) than in MCF-7 (wt p53) and CaCo-2 cell line, which was the most resistant to p53 overexpression despite the p53 mutation. Unlike HeLa and SW 620 cells, the basal p21 protein level was readily detected in CaCo-2 and MCF-7 cells. Overexpression of p21(WAF1/CIP1) gene induced somewhat less pronounced growth inhibition of all cell lines tested, but it also induced apoptosis in HeLa and SW 620 cells. These results suggest that the basal, but not the inducible, levels of p21(WAF1/CIP1) protein in tumor cells could protect from p53-mediated apoptosis. On the other hand, overexpression of p21(WAF1/CIP1) gene itself can induce apoptosis in cells with no basal p21(WAF1/CIP1) protein level. Possible mechanisms of the differential response to these genes are discussed.

The role of insulin-like growth factor 2 and its receptors in human tumors

Insulin-like growth factor 2 (IGF-2) is important for normal development and growth of an organism. In humans it is encoded by 11p15.5 paternally expressed imprinted gene. It binds at least two different types of receptors: IGF type 1 (IGF-1R) and IGF-2/mannose 6-phosphate receptors (IGF-2R/M6P). Ligand binding to IGF-1R provokes mitogenic and anti-apoptotic effects. IGF-2R/M6P has tumor suppressor function; it mediates IGF-2 degradation. When the IGF-2 gene/protein is overexpressed, mostly as a consequence of loss of heterozygosity resulting in paternal allele duplication (LOH) or by loss of imprinting (LOI), it is involved in the development and progression of many tumors and overgrowth syndromes by autocrine or paracrine mechanisms.

[Prostate gland-transition zone lesions. Etiology, growth regulation, growth factors, genetic changes]

Human prostate gland is a composite organ made up of several glandular and nonglandular components. There are three distinct glandular regions. These are the peripheral, the central, and the transition zone. They differ histologically and biologically. The central zone is relatively resistant to carcinoma and other diseases. The peripheral zone is the site of origin of most carcinomas and prostatic intraepithelial neoplasia (PIN). Most authors now agree that PIN is a likely precursor of at least a proportion of carcinomas arising in this zone. The transition zone is the exclusive site of origin of benign prostatic hyperplasia (BPH). A subset of prostate cancers arises in this zone as well. Most are found incidentally at transuretral resection (TUR). A morphological lesion, atypical adenomatous hyperplasia (AH), arising also in transition zone, provides a possible link between BPH and transition zone cancers. However, further studies of biological markers of neoplastic transformation are needed to address this issue.

Novel alleles of the D16S752 polymorphic genetic marker linked to E-cadherin gene--a potential population marker

Seven DNA variants that polymorphic genetic marker D16S752 reveals in Croatian population are reported in this paper. The marker is a GATA tetranucleotide repeat linked to human E-cadherin gene (CDH1). Prior studies involving this marker revealed only four DNA allele variants. The reported DNA variants contribute to the collection of hypervariable DNA polymorphisms data useful in the field of anthropological and population genetic and forensic medicine.

Insulin-like growth factor family and combined antisense approach in therapy of lung carcinoma

BACKGROUND

Perturbation in a level of any peptide from insulin-like growth factor (IGF) family (ligands, receptors, and binding proteins) seems to be implicated in lung cancer formation; IGF ligands and IGF-I receptor through their mitogenic and anti-apoptotic action, and the mannose 6-phosphate/insulin-like growth factor II receptor (M6-P/IGF-IIR) possibly as a tumor suppressor.

MATERIALS AND METHODS

To determine the identity, role, and mutual relationship of IGFs in lung cancer growth and maintenance, we examined IGF's gene (by RT-PCR) and protein (by immunohistochemistry) expression in 69 human lung carcinoma tissues. We also examined IGF-I receptor numbers (Scatchard analysis) and IGF-II production and release (by Western blot) in IGF-II/IGF-IR mRNA positive and negative lung carcinomas. Finally, the potential role of IGF-IR and IGF-II as growth promoting factors in lung cancer was studied using antisense oligodeoxynucleotides that specifically inhibit IGF-IR and IGF-II mRNA.

RESULTS

Thirty-two tumors were positive for IGF-I, 39 for IGF-II, 48 for IGF-IR, and 35 for IGFBP-4 mRNA. Seventeen tumors were concomitantly positive for all four IGFs, whereas 34 were positive for IGF-II, IGF-IR, and IGFBP-4 mRNA. An elevated amount of IGF-II peptide was secreted into the growth medium of cell cultures established from five different IGF-II/IGF-IR mRNA positive lung cancer tissues. The cells also expressed elevated numbers of IGF-IR. Nine IGF-II-negative and 19 IGF-II-positive lung cancers of different stages were selected, and M6-P/ IGF-II receptor was determined immunohistochemically. Most of the IGF-II-negative tumors were strongly positive for M6-P/IGF-IIR. IGF-II-positive tumors were mostly negative for M6-P/IGF-II receptors. Antisense oligodeoxynucleotides to IGF-II significantly inhibited, by 25-60%, the in vitro growth of all six lung cancer cell lines. However, the best results (growth inhibition of up to 80%) were achieved with concomitant antisense treatment (to IGF-IR and IGF-II).

CONCLUSION

Our data suggest that lung cancer cells produce IGF-IR and IGF-II, which in turn stimulates their proliferation by autocrine mechanism. Cancer cell proliferation can be abrogated or alleviated by blocking the mRNA activity of these genes indicating that an antisense approach may represent an effective and practical cancer gene therapy strategy.

Natural zeolite clinoptilolite: new adjuvant in anticancer therapy

Natural silicate materials, including zeolite clinoptilolite, have been shown to exhibit diverse biological activities and have been used successfully as a vaccine adjuvant and for the treatment of diarrhea. We report a novel use of finely ground clinoptilolite as a potential adjuvant in anticancer therapy. Clinoptilolite treatment of mice and dogs suffering from a variety of tumor types led to improvement in the overall health status, prolongation of life-span, and decrease in tumors size. Local application of clinoptilolite to skin cancers of dogs effectively reduced tumor formation and growth. In addition, toxicology studies on mice and rats demonstrated that the treatment does not have negative effects. In vitro tissue culture studies showed that finely ground clinoptilolite inhibits protein kinase B (c-Akt), induces expression of p21WAF1/CIP1 and p27KIP1 tumor suppressor proteins, and blocks cell growth in several cancer cell lines. These data indicate that clinoptilolite treatment might affect cancer growth by attenuating survival signals and inducing tumor suppressor genes in treated cells.

The efficacy of retroviral herpes simplex virus thymidine kinase gene transfer and ganciclovir treatment on the inhibition of melanoma growth in vitro and in vivo

One approach to gene therapy of cancer is based on the insertion of a suicide gene into tumor cells and subsequent activation of the suicide mechanism. We used the herpes simplex virus thymidine kinase (HSVtk) gene followed by ganciclovir (GCV) treatment. The goal of our experiments was to determine the effectiveness of HSVtk gene therapy in malignant melanoma. B16BL6 murine melanoma cells retrovirally transduced with the HSVtk gene became sensitive to low concentrations of GCV. Analysis by RT-PCR showed HSVtk expression in transduced B16BL6tk+ cells. Apoptotic cell death was found in B16BL6tk+ cells treated with GCV (20 microM). The sensitivity of B16BL6tk+ cells to GCV was also examined in vivo. Tumors inoculated subcutaneously into C57BL6 mice regressed rapidly when treated with GCV (50 mg/kg twice a day) and disappeared completely after 14 days treatment. The mice remained in remission for 5 months. A bystander effect through which nontransduced B16BL6 cells were also inhibited by GCV administration when cocultured with B16BL6tk+ cells was expected. However, only slight killing of nontransduced cells was observed in vitro. Analysis of the bystander effect in vivo showed complete regression of tumors inoculated with a mixture of cells mostly consisting of B16BL6tk+ cells. A distant bystander effect was also examined. There was no regression of wild-type tumors raised at a distant site from primary B16BL6tk+ tumors. The failure of a more effective bystander effect indicates the need for further investigation of the possible use of combined gene therapy to treat melanoma.

Helicobacter pylori colonization of tongue mucosa--increased incidence in atrophic glossitis and burning mouth syndrome (BMS)

Nested polymerase chain reaction (PCR) was performed to detect the presence of Helicobacter pylori in tongue mucosa in 268 patients divided into four groups according to their diagnosis: 87 with atrophic glossitis, 37 with benign migratory glossitis and 144 with burning mouth syndrome (BMS). The latter group was subdivided according to anatomic site of burning sensation: subgroup A (54 patients) with complaints limited to tongue and subgroup B (90 patients) with burning sensations in other parts of oral mucosa. H. pylori was found in 43 samples (16%). Bacteria were significantly less present in tongue mucosa affected with benign migratory glossitis compared with atrophic glossitis and BMS (P=0.025). This difference was more obvious when compared with atrophic glossitis only (P=0.006). Mucosal changes in these conditions might make the oral environment more acceptable for H. pylori colonization compared with normal mucosa, and this mechanism may play a role in its oro-oral transmission.

The expression and role of insulin-like growth factor II in malignant hemangiopericytomas

Hemangiopericytoma is a rare soft tissue tumor originating from contractile pericapillary pericytes. To address the issue of molecular genetic events that participate in genesis and progression of hemangiopericytoma we analyzed insulin-like growth factor (IGF) II and IGF I receptor in 29 tumors collected from a human tumor bank network. Seven of these tumors were associated with severe hypoglycemia; six were retroperitoneal and one was located in the leg. Of 22 tumors tested 12 (54.5%) exhibited IGF II mRNA, while almost 90% (17 of 19) of hemangiopericytomas exhibited IGF I receptor mRNA. Sera from some patients whose tumors expressed IGF II mRNA contained elevated levels of IGF II. Removal of the tumor eliminated most of the IGF II immunoreactivity from the sera. The potential role of IGF II as a growth-promoting factor was examined on three malignant primary hemangiopericytoma cell cultures. Extracellular addition of IGF II significantly enhanced cell proliferation in a dose-dependent manner. Antisense oligodeoxynucleotides that specifically inhibit IGF II mRNA, at a concentration of 40 or 80 micrograms/ml, inhibited the growth of hemangiopericytoma cells significantly, by 40%. Simultaneous administration of antisense deoxyoligonucleotides to both IGF II and IGF I receptor inhibited tumor cell proliferation by even 80%. Our data suggest that tumor cells produce IGF II, and that this in turn stimulates their proliferation by autocrine mechanisms.

Loss of heterozygosity and protein expression of APC gene in renal cell carcinomas

This study evaluated the potential contribution of the APC gene to malignant transformation in patients with renal cell carcinoma. We tested 36 human renal cell carcinoma samples and 18 adjacent normal kidney tissues for the expression of APC protein, both wild and truncated types, by western blot using antibodies that recognize either the carboxy or the amino epitope of the APC protein. The same tumor samples together with autologous peripheral blood were also analyzed at the DNA level. Using specific oligonucleotide primers for exons 11 and 15, gene instability was followed by polymerase chain reaction/loss of heterozygosity (LOH) (on the basis of restriction fragment length polymorphism). Molecular data were also compared to pathohistological diagnosis, TNM stage, and patient's age using multivariate statistical methods. All normal renal tissues revealed expression of the wild-type APC protein. Neither wild nor mutant type proteins were found in 36% (13/36) of tumor samples; the rest of tumor tissues expressed the wild-type protein (312 kDa). Mutated APC protein, with a molecular weight of 117 kDa, was found in only one tumor sample. From 36 tumor samples 16 (44.4%) were informative for RsaI exon 11 polymorphic site, while only half of these (8/16) demonstrated LOH. From 13 tumor samples that had no detectable protein product by western blot analysis eight were homozygous for the exon 11 polymorphism and were tested for another polymorphic site, MspI/exon 15. The overall proportion of LOH cases for both polymorphisms tested was 52.9% (9/17). Pathohistological diagnosis and molecular data showed no correlation. However, multivariate analysis determined a stage strong positive correlation of age and TNM with the presence of LOH and the absence of the wild-type APC protein. Out results suggest that the APC tumor suppressor gene plays a role in renal carcinogenesis. Alterations in this gene are responsible for tumor evolution and progression, but cannot be considered as a first event in tumor initiation.

Molecular pathology of hemangiopericytomas accompanied by severe hypoglycemia: oncogenes, tumor-suppressor genes and the insulin-like growth factor family

Relatively little is known about molecular genetic events that participate in the genesis and progression of hemangiopericytoma. In this study, we describe two cases of hemangiopericytoma accompanied by severe hypoglycemia. Tumor cells from patient 1 exhibited insulin-growth factor I (IGF I) and insulin-like growth factor I receptor (IGF IR) mRNA transcripts. Tumor cells from patient 2 exhibited IGF II, IGF IR and IGF binding proteins 1-3 mRNA. Serum from patient 2 contained IGF II, mostly in a large molecular form ("big" IGF II); the IGF II level did not change after the tumor removal. The presence of IGF IR in tumor cells was confirmed by immunoprecipitation with antibodies that recognize human IGF IR subunit (visualized as a 460-kDa band). The hemangiopericytoma cells derived from patient 1 expressed 210000 IGF I receptors/cell. Specific binding of IGF I to the tumor cell membrane fraction was higher in tissue from patient 1, while the tissue of patient 2 showed relatively low IGF I binding. In contrast, IGF II binding was much higher in tissue from patient 2. Both tumor tissues showed positive immunostaining for c-Jun; one tumor showed strong immunostaining for c-Myc, H-Ras and p53, while the other exhibited strong reaction with H-Ras antibodies only. No loss of the heterozygosity at the genes APC, NFI and nm23-H1 loci in tumor tissue obtained from patient 1 was found. In effect, our results suggest multiple molecular genetic changes in hemangiopericytoma -- activation of some oncogenes and the IGF growth factor family. IGF ligands together with IGF IR could be responsible for hypoglycemia and perhaps the transformed phenotype.

Detection of Helicobacter pylori in various oral lesions by nested polymerase chain reaction (PCR)

Nested PCR was used for the detection of Helicobacter pylori DNA in specimens collected from seven different topographic sites in the oral cavity. Out of 161 patients, only 21 (13.04%) were positive. There was no correlation between H. pylori status and patient diagnosis and age. No preferential site for bacterial colonization was found in the oral cavity, nor was an association established between a bacterial presence and ulcerated versus non-ulcerated lesions. The results indicate that the oral mucosa does not appear to represent a preferred site of colonization for H. pylori. Furthermore, the evidence presented in this paper suggests that H. pylori is not pathogenic in the oral cavity, nor is it associated with common oral pathologic processes.

Squamous cell lung carcinomas: the role of nm23-H1 gene

This analysis of 32 pairs of human squamous cell lung carcinomas and normal matched control DNA demonstrates that loss of heterozygosity (LOH) is infrequent at the nm23-H1 locus, affecting only 2 of the 18 informative cases. Both LOH cases were in the tumor stage IIIA. One tumor was of poor and the other of moderate histological grade. These and an additional 34 tumor samples were also analyzed immunohistochemically for the presence of nm23-H1 protein. Of the 66 cases tested for the presence of nm23-H1 protein 54 were negative. Eight samples exhibited up to 35% positive cells (with weak immunostaining intensity) and four between 35% and 70% (moderate immunostaining intensity); no sample showed more than 70% positive cells. Noncancerous lung parts contained no nm23-H1 protein. nm23-H1 expression was independent of TNM stage, grade, tumor size, and patient's survival. Two samples with LOH were negative for nm23-H1 protein. We therefore conclude that neither loss of heterozygosity of the nm23-H1 gene nor the intensity of specific protein expression are related to squamous cell lung carcinoma development and progression.

4,9-diazapyrenium dications induce apoptosis in human tumor cells

We investigated the antiproliferative effects of two planar 4,9-diazapyrenium hydrogenasulphates against human malignant MiaPaCa 2 (pancreatic carcinoma), Hep 2 (laryngeal carcinoma) and human normal fibroblasts (WI 38) cell lines. The tested compounds were very potent in inhibiting the growth of the treated cell lines. Treatment with molar concentrations of the substances (10(-4)-10(-7) M) caused growth inhibition by more than 50%. The morphological changes of treated cells were also observed. Cells became smaller, with condensed chromatin and fragmented nuclei, the characteristics of dying cells. The identification of DNA-fragmentation and the appearance of chromatin aggregation leads us to assume the tested substances induced apoptosis of the investigated tumor cell lines.

Concomitant point mutation of tumor suppressor gene p53 and oncogene c-N-ras in malignant neuroendocrine pancreatic tumor

Activation by point mutation of ras family genes as well as point mutations of the p53 tumor suppressor gene are found in many tumors. Here we describe a rare case of malignant neuroendocrine pancreatic tumor with multiple metastases in different organs showing strong positivity for synaptophysin, glucagon-like peptide 1, pan-cytokeratin, moderate positivity for chromogranin, Phe-5 and calcitonin and weak positivity for vasointestinal peptide. We found a point mutation at codon 61 of the c-N-ras oncogene, and point mutations in the p53 tumor suppressor gene in the primary tumor as well as in its metastases in liver. The mutation in the c-N-ras gene was a cytosine to adenine transversion, resulting in the amino-acid lysine. Allele specific hybridization showed that the mutation involved one of two c-N-ras alleles as the oligonucleotide for the normal codon also hybridized to amplified tumor DNA. Concomitant mutation of the p53 tumor suppressor gene at codons 248 and 249 was found. The mutation in codon 248 was a cytosine to guanine transversion resulting in the amino-acid glycine. The mutation in codon 249 was a third base, G- > T, transversion leading to a change from arginine to serine. This is the first time that concomitant point mutations in c-N-ras and p53 have been found in a neuroendocrine pancreatic tumor. Based upon these and our previous results, we concluded that these genetic changes may play a role in the development of this particular pancreatic tumor.

Nested polymerase chain reaction for detection of hepatitis C virus RNA in blood derivatives

Testing for the presence of hepatitis C virus (HCV) in blood derivatives used in clinical medicine is of enormous importance to ensure the production of safe preparations. So far, no system has been developed for the isolation and detection of hepatitis C virus from blood derivatives. The recently introduced commercial kit for the detection of hepatitis C virus is designed for the isolation and detection of virus from blood serum. A reliable and reproducible method for the isolation of hepatitis C virus RNA, subsequent reverse transcription and nested polymerase chain reaction (PCR) from blood derivatives is described. Of 17 batches of factor VIII, gamma-globulin and anti tetanus, cytomegalovirus and Varicella-zoster immunoglobulin concentrates, respectively (14 negative for anti HCV and 3 of unknown anti HCV status) five were found positive in RNA-PCR.

p53 immunoreactivity in oligodendrogliomas

Data are presented on p53 protein presence in human oligodendrogliomas whose progress from low grade to anaplastic oligodendroglioma can be followed. Expression was evaluated by formalin-fixed paraffin-embedded section immunohistochemistry, using monoclonal PAb 1801 antibody. The frequency of p53 protein accumulation is related to the stage of tumor malignancy. All the samples (100%) of malignant oligodendrogliomas were positive for p53 protein. Of 14 type II oligodendroglioma samples, 9 were positive (64%) while among type I oligodendroglioma the positivity was 28%. The mean proportion of reactive cells was also higher in malignant oligodendrogliomas. However, mean intensity staining did not differ among various grades of tumors. Our results point to the direct link between p53 protein accumulation and the malignant stage of human oligodendrogliomas. However, the value of p53 protein accumulation in predicting malignant behavior of oligodendrogliomas requires further confirmation.

DNA amplification by polymerase chain reaction from brain tissues embedded in paraffin

A method which enables analysis of DNA from archival paraffin embedded normal and malignant brain tissue is described. The demonstration of a 317-bp long beta-actin DNA sequence by the polymerase chain reaction (PCR) was used to identify which fixation procedure, deparaffinization time and DNA extraction procedure would give the best results. Tissue specimens 1-39 years old were included in the experiments. Specimens fixed in either 10% formalin, Carnoy's or AMeX fixative were found to be best suited for subsequent analysis by PCR. Paraformaldehyde and acetone compromised amplification efficiency, while Bouin's fixed tissue gave uniformly negative results. Regardless of fixative used, PCR reaction had to be run through at least 40 cycles. Prolonged deparaffinization time and phenol/chloroform extraction of DNA did not influence DNA quality as a template for PCR reaction. Formalin fixed brain tumours can be successfully used for DNA/PCR analysis even if they are up to 39 years old.

PCR amplification of DNA from stained cytological smears

DNA from archival Papanicolaou stained smears was successfully amplified using the polymerase chain reaction (PCR) to see if it could be used for retrospective genome studies such as detection of the presence of human papilloma virus (HPV) and changes in p53 gene expression. DNA was isolated and purified by treatment with proteinase K, phenol/chloroform, and isoamyl alcohol. Segments of the human beta actin and TGF beta 1 gene were amplified by PCR. Of all stains used in the preparation of Papanicolaou smears, only eosin was detectable as a greenish band in ethidium bromide treated DNA gels under ultraviolet illumination.