Molecular characterization of bovine rotavirus strains circulating in northern Italy, 2003-2005.

A total of 232 stools collected from calves with rotavirus infection in herds located in northern Italy from 2003 to 2005 was investigated. Determination of the rotavirus G and P types was carried out using nested RT-PCR. G6 was the most prevalent genotype, accounting for 78.5% of samples, G10 accounted for 9.9% of samples and viruses of G8 type were found in 4.7% of samples. In 3% of samples, viruses were not classified due to concomitant infection with more G type strains, whereas viruses in 3.9% of samples could not be characterized with any of the G-specific primers used in this study. Most common P types were P[11] and P[5], accounting for 65.1% and 25%, respectively. In 2.6% of cases, samples reacted with multiple P-specific primers; no P[1] serotype was identified. The G6P[11] combination was predominant throughout the study period, i.e. 52.5% in 2003, 50% in 2004 and 40% in 2005. The incidence of G6P[5] increased from 13.1% in 2003 to 27% in 2004 and 25.5% in 2005. The G10P[11] combination decreased markedly from 18% in 2003 to 2.6% in 2004, rising again to 7.3% in 2005. G8P[11] viruses were similarly present in 2003 (5%) and 2004 (4.3%), declining slightly in 2005 (1.8%).

Alterations of microsatellites in neurofibromas of von Recklinghausen's disease.

von Recklinghausen's disease, or type I neurofibromatosis, a common familial tumor syndrome, is characterized by the occurrence of multiple benign neoplasms of nerve sheath cells. The disease is caused by germ-line mutations of the NF1 gene, which encodes a member of the GTPase-activating superfamily of Ras regulatory proteins. We analyzed 5 dinucleotide repeat loci in DNAs from neurofibromas and matched normal skin from 16 NF1 patients. Eight cases (50%) manifested microsatellite alterations. Expansions or compressions of dinucleotide repeats were observed at one locus in four cases and at two loci in one case. Banding patterns compatible with the loss of a microsatellite allele were observed in four cases, including one that also presented microsatellite instability. The surprisingly high frequency of microsatellite alterations suggests that the NF1 gene or another gene(s) contributing to the pathogenesis of neurofibromas might be directly or indirectly implicated in the control of genomic integrity.

Integrin (alpha 6/beta 4) expression in human lung cancer as monitored by specific monoclonal antibodies.

In this study, the expression of the alpha 6/beta 4 integrin complex was analyzed in human lung carcinomas both in vitro and in vivo, using two monoclonal antibodies which recognize the integrin subunits alpha 6 (Mab 135-13C) and beta 4 (Mab 439-9B). Immunoprecipitation patterns obtained from established human lung carcinoma cell lines demonstrated that the alpha 6 and the beta 4 subunits were differentially expressed in carcinomas of different types. The alpha 6 subunit was expressed in all the cell lines tested (squamous cell carcinoma A431, adenocarcinoma A549, large cell carcinoma DG3, and small cell carcinoma AE2). The beta 4 subunit was expressed in non-small cell cancer lines but was not detectable in the small cell cancer line tested. Using a quantitative two-site assay, we measured the concentration of the alpha 6/beta 4 integrin in matched biopsies from primary lung tumors and from normal lung. These studies confirmed that the complex was differentially expressed in non-small versus small cell lung cancers and that it was also detectable in lysates from normal lung at low levels. The highest levels of alpha 6/beta 4 were found in moderately differentiated squamous cell carcinomas. By immunohistochemistry, the beta 4 subunit was detectable in all the squamous cell carcinoma and adenocarcinomas tested (a total of 59), but not in 10 small cell cancers. The patterns of immunoreactivity were consistent with the expected distribution of membrane glycoproteins and, in some squamous cell carcinomas, were suggestive of the localization displayed by molecules involved in carcinoma-stroma interaction. Immunohistochemical staining indicated that beta 4 was also expressed in specific types of nonrespiratory pulmonary epithelial cells.

Complementary reactivities of anti-carcinoembryonic antigen and antitumor-associated glycoprotein 72 monoclonal antibodies in lung carcinomas.

Monoclonal antibodies (MAbs) COL-4 and COL-12, to the carcinoembryonic antigen (CEA), and B72.3, CC-49, CC-83, to the tumor-associated glycoprotein 72 (TAG-72), were used to study the expression of distinct epitopes of the two molecules in 71 cases of lung carcinoma of differing histotype. These MAbs reacted with the majority of adenocarcinomas by immunoperoxidase on tissue sections, but demonstrated a more restricted reactivity with squamous carcinomas. MAb CC-49 detected the highest percentages of adenocarcinoma cells while the B72.3 epitope was expressed more in squamous carcinoma cells. No significant reactivity with any of these MAbs was observed in small cell carcinomas. The expression of the CEA and TAG-72 epitopes in non-small cell lung cancers was highly heterogeneous: a distinct epitopes in non-small cell lung cancers was highly heterogeneous: a distinct epitope could be expressed by the majority of cells, whereas another of the same antigenic molecule was either poorly or not expressed. In adenocarcinomas, mixtures of anti-CEA, anti-TAG-72, and anti-(TAG-72 plus CEA) MAbs resulted in additive reactivity with an increase of the immunopositive tumors and of the percentages of immunostained cells. This was particularly evident for the anti-(TAG-72 plus CEA) mixture. In squamous cell carcinomas the increase was modest and was mainly related to anti-TAG-72 reactivity. These studies suggest variability in the antigenic structure of tumor-associated antigens expressed by carcinomas and indicate that anti-(TAG-72 plus CEA) mixtures may represent an immunological adjunct for clinical application in adenocarcinoma patients. On the other hand, TAG-72 should be considered a better target antigen, as compared to CEA, in the detection of squamous cell carcinomas.

Unbalanced germ-line expression of hMLH1 and hMSH2 alleles in hereditary nonpolyposis colorectal cancer.

We analyzed the hMLH1 and hMSH2 genes in 30 unrelated hereditary nonpolyposis colorectal cancer (HNPCC) patients using mutational and immunohistochemical analyses combined whenever possible with primer extension assays, designed to estimate hMLH1 and hMSH2 transcript expression in peripheral blood lymphocytes. Single-strand conformational polymorphism screening and PCR-direct sequencing revealed seven hMLH1 and five hMSH2 sequence variants in 14 unrelated HNPCC patients, including three definite pathogenic mutations, four amino acid substitutions of uncertain pathogenic significance, and five polymorphisms. Immunohistochemistry indicated the lack of either hMLH1 or hMSH2 protein expression in tumors from 13 patients, and the absence of both hMLH1 and hMSH2 immunostaining was observed in the tumor from one additional case. The lack of hMLH1 or hMSH2 immunostaining was associated with the presence of microsatellite instability in the corresponding tumor and was also observed in tumors from patients negative for pathogenic mutations by mutational screening. There was a marked unbalance in the allelic expression of either hMLH1 or hMSH2 transcripts in three of eight unrelated HNPCC patients that could be analyzed, although a less marked unbalance was detected in two additional patients. Tumors from patients with germ-line unbalance in hMLH1 or hMSH2 transcript expression did not express the corresponding mismatch repair protein and displayed microsatellite instability. Our results indicate that constitutional alterations in hMLH1 and hMSH2 transcript expression may represent genetic markers for HNPCC carrier status also in cases in which mutational analysis did not detect a definite pathogenic variant. This suggests that transcript deregulation may represent a relevant mode of germ-line inactivation for mismatch repair genes.

Purification of human erythrocyte proteolytic enzyme responsible for degradation of oxidant-damaged hemoglobin. Evidence for identifying as a member of the multicatalytic proteinase family.

Exposure of human red cells to oxidants such as phenylhydrazine, 2,4-dimethylphenylhydrazine and 4-hydrazinobenzoic acid stimulates the proteolysis of hemoglobin as evidenced by the increase in the rate of the free alanine and acid soluble amino groups released. An enzyme responsible for proteolytic degradation of oxidized hemoglobin, was purified from cytosolic fraction of erythrocytes by a DEAE-batch procedure followed by gel-filtration and ion-exchange chromatography. The final enzyme preparation produces a single band in non-denaturing polyacrylamide gel electrophoresis, and eight different bands of 23-32 kDa when subjected to polyacrylamide gel electrophoresis under denaturing conditions. The native enzyme has a molecular mass of about 700 kDa as estimated by gel filtration. The enzyme, unable to hydrolyze native hemoglobin, cleaves phenylhydrazine-treated hemoglobin into small peptides without free amino acid release. In addition, the enzyme shows an endopeptidase activity towards synthetic peptides having a tyrosine or an arginine in the P1 position, whereas it does not hydrolyze shorter peptides and those with a proline in the P1 or P2 position. The proteolytic activity of the enzyme against oxidized hemoglobin is inhibited by chymostatin and p-chloromercuribenzoate, while it is stimulated by N-ethylmaleimide and epoxysuccinylleucylamido-(4-guanidino)butane (E-64). The peptidase activity assayed on succinyl-Leu-Leu-Val-Tyr-MCA is inhibited by chymostatin, hemin, N-ethylmaleimide and p-chloromercuribenzoate. The results obtained show that in human erythrocytes oxidized hemoglobin is cleaved into peptides by a high molecular mass proteinase identified as a member of the multicatalytic proteinase family. It is also suggested that the complete degradation of oxidized hemoglobin to free amino acids requires the involvement of a further proteolytic enzyme(s) which remain(s) to be identified.

Microsatellite instability is correlated with lymph node-positive breast cancer.

We analyzed 81 cases of primary breast carcinoma and 7 cases of fibroadenoma for microsatellite instability at eight loci. Twenty-seven cases (33.3%) manifested aberrant microsatellite alleles: 7 (8.6%) at one locus and 20 (24.7%) at two or more loci [tumors with replication error-positive (RER+) phenotype]. No evidence of microsatellite instability was observed in fibroadenomas. We investigated correlations between RER+ phenotype and clinicopathological characteristics of the carcinomas. The RER+ phenotype was statistically associated with large tumor diameter; of 19 RER+ tumors with measured size, 16 were > 2 cm, compared to 28 of 58 tumors with no evidence of microsatellite instability or with shifts in allele sizes limited to one locus (P

Anti-IgM antibody decreases dissociability of cell bound IgM anti-hapten antibodies as measured with fluid phase hapten.

We studied the effect of an IgG anti-IgM on the dissociation of cell bound IgM anti-hapten antibody, as measured with fluid phase hapten. Methotrexate (MTX) covalently bound to the red cells surface was used as hapten; rabbit anti-MTX IgM and rabbit anti-allotype IgG reactive with the IgM were used as antibodies. The amount of cell bound antibodies was measured with 125I-labelled protein A. In the absence of the anti-allotype antibody, most of the anti-hapten IgM was prevented from reassociation by fluid phase hapten. In the presence of the anti-allotype IgG most of the anti-hapten IgM was non-dissociable, with about a 1000-fold increase in the apparent binding constant. We found that (1) dissociability of the anti-hapten IgM depended on the density of the cell bound hapten, (2) decrease in dissociability was a function of the anti-allotype antibody concn and (3) even in the presence of excess anti-allotype antibody dissociability was an inverse function of anti-hapten IgM concn.

Activation of hemolytic complement by mouse monoclonal IgG1 antibody: comparison with rabbit IgG.

We investigated the ability of a mouse anti-hapten monoclonal IgG1 antibody (Ab) to bind to cell-bound specific hapten and to fix and activate C1 and thus the lytic sequence of complement (C). In a comparative study with polyclonal rabbit anti-hapten IgG Ab, we found that about 6 times more monoclonal Ab molecules than polyclonal were necessary for the generation of 1 hemolytic site/cell: the data were interpreted to mean that a cluster of four cell-bound monoclonal Ab molecules was necessary to bind C1 and activate C-mediated hemolysis. Experiments performed under conditions of low density of cell-bound hapten and excess of antibody showed that both monoclonal and polyclonal IgG Abs were able to react only with 20-30% of the cell-bound hapten and that both Abs recognized the same hapten specificity. We also found that even though monoclonal IgG1 Ab was able to bind strongly to a protein A-Sepharose column and could be eluted only by a low-pH buffer, the purified Ab, when bound to cell surface hapten, showed a weak ability to react with free protein A.

Efficiency of activation of complement by anti-hapten antibodies at the red cell surface: effect of patchy vs random distribution of hapten.

Binding and activation of complement (C) by anti-hapten IgG and IgM antibodies (Abs) bound to a cell surface are dependent on the density and presumably on the distribution of cell-bound hapten. The purpose of this study was to find out if altering the distribution of the hapten on a red cell surface could modify the ability of anti-hapten IgG or IgM Ab to activate C. To test this we devised methods for comparing the C binding and activating efficiency of Abs bound to a hapten distributed randomly or in patches on cells. Random distribution was achieved by the covalent binding of methotrexate (MTX) directly to sheep red blood cells (E), while patchy distribution was achieved by the convalent binding to E of bovine serum albumin-MTX complexes. We considered bound albumin molecules as patches of MTX molecules. The results showed that, for IgG Ab, the number of hapten/E and the number of anti-hapten Ab molecules/cell required to generate one C-activating IgG complex were about an order of magnitude lower for hapten bound in patches than for randomly bound hapten. In contrast, IgM Ab bound to a hapten distributed in patches on an E surface lacked the ability to activate the lytic sequence of C, although maintaining a full ability to binding C1.

BRCA1 and BRCA2 mutations in breast/ovarian cancer patients from central Italy.

We report on the screening of the entire BRCA1/BRCA2 coding sequence by SSCP, PTT, and direct sequencing in 68 Italian families with recurrent breast or ovarian cancer. For each investigated proband, the probability of being carrier of a BRCA1/BRCA2 mutation was evaluated using the BRCAPRO software. We detected BRCA1/BRCA2 mutations in 8 patients (11.7%). However, if considering only patients with a carrier probability >10%, the detection rate was 36.8%, confirming the usefulness of the BRCAPRO software. One change (BRCA1 4172insT) was a novel mutation not reported in BIC database.

Thyroid carcinoma usually occurs in patients with familial adenomatous polyposis in the absence of biallelic inactivation of the adenomatous polyposis coli gene.

Papillary thyroid carcinoma (PTC) is a rare extracolonic manifestation of familial adenomatous polyposis, determined by germline mutations of the adenomatous polyposis coli (APC) gene. The aim of this study was to assess the presence of loss of heterozygosity of APC in the thyroid tumoral tissue. Specimens from six female patients, aged 20-36, were analyzed for germline and somatic mutations of the APC gene by restriction enzyme analysis and sequence analysis. Five of the six also had analysis for ret/PTC, a chimeric gene, the activation of which is restricted to papillary TC. Because a previous study showed that germline mutations in familial adenomatous polyposis-associated thyroid carcinoma were located between codons 140 and 1513, the search for somatic mutations of the APC gene was restricted to this genomic area. Three of the six patients, belonging to the same kindred, had a germline mutation at codon 1061. The remaining three, one per kindred, had germline mutations at codons 1061, 1061, and 1309, respectively. None of the six patients had loss of heterozygosity for APC or somatic mutation in the explored genomic area (codon 545 and codons 1061-1678). Four of five had activation of ret/PTC in the thyroid tumoral tissue, as ret/PTC1 isoform. Either APC has a tissue-specific dominant effect in the thyroid gland or the germline mutation confers a generic susceptibility to cancer development, but other factors (sex-related factors, environmental radiation, modifier genes) are also required for TC development. This usually involves ret/PTC activation, suggesting a possible cooperation between altered function of APC and gain of function of ret.

Transcripts with splicings of exons 15 and 16 of the hMLH1 gene in normal lymphocytes: implications in RNA-based mutation screening of hereditary non-polyposis colorectal cancer.

Germline mutations of the hMLH1 gene are estimated to account for a large fraction of kindreds affected by hereditary non-polyposis colorectal cancer (HNPCC). In a significant number of cases, hMLH1 mutations result in the expression of truncated proteins. We report here two novel alternatively spliced forms of hMLH1 mRNA in normal lymphocytes. One of these novel isoforms lacks the coding region of the gene between codons 557 and 578, corresponding to the entire exon 15. The deletion introduces a frameshift that results in a premature stop signal. The other isoform is characterised by an in-frame deletion spanning codons 578-632, corresponding to loss of the entire exon 16. Further studies are necessary to establish the biological significance of these alternative splicings. The presence of alternatively spliced hMLH1 transcripts that mimic pathogenic mutations should be taken into account in the mutational screening of the hMLH1 gene by reverse transcription-polymerase chain reaction methodologies.

Differential control of placental lactogen release and progesterone production by ovine placental tissue in vitro.

The hypothesis that placental secretion of progesterone (P4) and ovine placental lactogen (oPL) are controlled through different mechanisms was tested. Placental tissue was obtained at days 133-138 of pregnancy, and explant incubations were established using 200 mg tissue per flask in 5 ml O2-saturated DMEM containing 24 mM HEPES and lacking phenol red (pH 7.4). Following a 30-min preincubation, and a 15-min control period, test substances were added and incubations continued, with periodic gassing, for 4 h at 37 degrees C in a shaking water bath. Dopamine (DA), norepinephrine (NE) and epinephrine significantly stimulated P4 production (P less than 0.05). The enhancement of placental P4 production was mimicked by the addition of 8-bromo-cyclic adenosine monophosphate and forskolin (P less than 0.05). The response to catecholamines was abolished by the addition of propranolol (P less than 0.05) but not by phentolamine (P greater than 0.05). Inclusion of a membrane-permeant substrate for P4 synthesis, 25-hydroxycholesterol, increased basal (P less than 0.05) but did not enhance agonist-induced P4 production (P greater than 0.05). High performance liquid chromatographic analysis of placental tissue demonstrated the presence of DA (80.8 +/- 7.07 pg/mg) and NE (48.8 +/- 5.77 pg/mg), as well as catecholamine metabolites. Addition of 1,2-dioctanoyl-sn-glycerol (DAG) or phorbol 12-myristate-13-acetate (PMA) enhanced oPL secretion (P less than 0.05) without affecting P4 production. The response to DAG and PMA, representing the release of considerably more oPL than can be detected by extracting the tissue, was not influenced by treatment with cycloheximide (P greater than 0.05) indicating that secretion of preformed oPL is regulated by the protein kinase C pathway. These results support the hypothesis that the secretion of oPL and the production of P4 are controlled by different mechanisms.

Mechanisms involved in the action of serotonin-induced stimulation of progesterone production by bovine luteal cells in vitro.

Serotonin (5-HT)-induced stimulation or progesterone (P4) production by bovine luteal cells was characterized with respect to the receptor subtype mediating this response, the steroidogenic response to 5-HT metabolites, the role of adenylate cyclase, and the 5-HT concentration of bovine luteal tissue. Addition of 5-HT (10(-5) M) stimulated the production of P4 (P less than 0.05) and this stimulation was inhibited by the 5-HT antagonist mianserin at a concentration of 10(-5) M (P less than 0.05), but not at a mianserin concentration of 10(-7) M. Additionally, the response to 5-HT could not be inhibited by ketanserin (10(-5) M), a 5-HT2 receptor antagonist. Incubation of luteal cells with a specific 5-HT1 agonist, (+/-)-8-hydroxydipropylaminotetralin HBr (DPAT) (10(-4) M), stimulated the production of P4 (P less than 0.05) and this response could not be blocked by mianserin at 10(-7) M or by ketanserin, but was inhibited by mianserin at 10(-5) (P less than 0.05). The addition of the 5-HT metabolite 5-methoxytryptamine (5-MTA) stimulated P4 production (P less than 0.05) and this response could be inhibited by mianserin (10(-5) M, P less than 0.05). Neither, N-acetyl-5-HT nor 5-methoxytryptophan significantly affected P4 production. The addition of the phosphodiesterase inhibitor 3-isobutyl-methylxanthine (IBMX, 0.1 mM) potentiated the effects of 5-HT and DPAT (P less than 0.05), but this effect was additive rather than synergistic. In contrast, the addition of luteinizing hormone (10 ng/ml) plus IBMX resulted in a significant synergistic response (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Novel allele of the hMLH1 gene bearing a TTC deletion in the 3' untranslated region.

SSCP analysis of the hMLH1 gene in two kindreds affected by hereditary nonpolyposis colorectal cancer (HNPCC) revealed the presence of unique conformers in all patients affected by colorectal cancer. Sequence analysis of the corresponding region of the gene revealed a 3 base pairs deletion within a TTC tandem repeat (G TTC TCC T-->G TTC T) beginning 29 base pairs downstream of the termination codon of the gene in the 3' untranslated region. This deletion causes the loss of an MboII restriction site. Analysis extended to 113 healthy unrelated individuals and 27 unrelated HNPCC patients demonstrated the occurrence of this novel variant of the hMLH1 gene at similar frequencies in unrelated HNPCC patients (3.7%) and in control individuals (2.2%). The allele bearing the TTC deletion appears to be expressed at levels comparable to those of the wild-type allele.

Microsatellite instability in early gastric cancer.

Microsatellite replication errors (RERs), consisting in random tumour-associated allele contractions or expansions, represent a frequent genetic alteration in gastric cancer and appear to be associated with important clinicopathologic parameters. To verify the role of microsatellite instability in the initial phases of gastric carcinogenesis, we analysed the status of II microsatellites in paired microdissected samples of tumour and unaffected mucosa from 30 cases of early gastric carcinoma. Fifteen tumours (50%) demonstrated RERs: these included 7 cases with RERs at one locus and 8 cases with RERs at 2 or more loci. Cases with 2 or more RERs were more frequent among intramucosal tumours, compared to tumours with submucosal spread (43% vs. 12%) and among tumours staged T1NOMx, compared to tumours staged T1N1Mx (35% vs. 0%). RER-positive microsatellite typings were statistically more frequent among tumours with intramucosal extension, lower stage (T1NOMx) and excavated growth pattern (macroscopic type III), compared to tumours with submucosal extension, higher stage (T1N1Mx) and elevated, flat or depressed growth patterns (macroscopic types IIa-IIb-IIc respectively). The above findings indicate that microsatellite instability occurs early in the progression of sporadic gastric cancer and tends to be associated with good prognostic indicators.

Mutational analysis of OB gene in obese and type 2 diabetes affected subjects.

Peripheral blood DNA from 12 subjects affected by familial obesity and from 35 subjects affected by type 2 diabetes were analysed for mutations in the coding sequence of the OB gene. Mutational analysis, conducted using the single strand conformation polymorphism (SSCP) technique, followed by direct sequencing did not reveal the presence of nucleotide variants in the coding region of the OB gene. The lack of mutations in the coding sequence is consistent with previous data suggesting that mutations in the coding sequence of the OB gene are not common in human familial obesity. In 2 samples displaying a non-informative pattern of SSCP and in 8 additional samples the nucleotide sequence of portion of the intron 2 bordering the coding sequence of exon 2 identified a G in the positions +14IVS and +18IVS, according to a sequence reported previously, but in contrast with some others. All samples were homozygous for these intron variants.

Cell kinetics and tumor-associated antigen expression in human mammary carcinomas.

Twenty-six primary breast carcinomas were studied to evaluate cell proliferation as assessed by thymidine labeling index (TLI), and antigenic phenotype, as defined by immunohistochemistry using eight monoclonal antibodies (MAbs) to tumor-associated antigens (TAAs). The majority of tumors had low TLI values. Reactivity to MAbs B72.3, CC49, CC83 (anti TAG 72), COL-12 (anti CEA) and MOv2 (against a tumor-associated mucoprotein) was restricted to less than 50% of the tumors studied, while MAbs B1.1 (anti CEA), MBrl and MBr8 (to tumor-associated carbohydrates) reacted with greater than 50% of the cases. Correlations between expression of TAAs and proliferative activity showed that the tumors could be divided into three groups, two characterized by either high proliferative activity and absence of antigenic expression or low proliferative activity and strong antigenic expression, and the third showing no relation between these two biological features. We defined two antigenic phenotypes associated with specific cellular kinetics: one characterized by negative immunoreaction with MAbs, CC49, CC83 and COL-12 and high proliferative activity; the other characterized by intense immunoreactivity with these antibodies and low proliferative activity. The data suggest that cell proliferation and antigenic phenotype may define biologic subsets of breast carcinomas.

Detection and counting of specific cell populations by means of magnetic markers linked to monoclonal antibodies.

We report on experiments aimed at the assessment of a new method for cell marking. This method combines superparamagnetic particles, commonly used for cell separation, linked to monoclonal antibodies, and biomagnetic instrumentation featuring an extremely high magnetic field sensitivity. The final goal of the method is to locate and estimate specific cell populations in the human body. In this experiment, quantitative features of the method are evaluated in vitro with lymphocytes and carcinoma cells. Comparison between estimation and direct counting of cells is quite satisfactory and motivates further development of the technique.