Leptin genotype is associated with lactation performance and health of Holstein cows

The objectives were to evaluate the associations among single nucleotide polymorphisms (SNP) in the R4C locus in exon 2 of the leptin gene and the lactational performance and health of Holstein cows. Eight hundred and fourteen lactating dairy cows had their DNA sequenced in exon 2 of the leptin gene to determine the presence of SNP in the R4C locus. Cows were milked 3 times daily, and yields of milk and milk components were recorded monthly individually during the first 305 d of lactation. Cows were examined daily by herd personnel for diagnosis of health events such as retained fetal membranes, displacement of abomasum, lameness, and mastitis. Resulting genotypes were CC (34.6%), CT (48.2%), and TT (17.2%). Cows bearing the CT genotype had lower body condition (2.98 +/- 0.02) during the first 62 d in milk (DIM) than cows homozygous for the C (3.02 +/- 0.02) and T (3.04 +/- 0.03) alleles. Leptin genotype was associated with yields of milk and milk components, and cows homozygous for the C allele were less productive than those carrying the CT and TT genotypes. The 305-d yields of 3.5% fat-corrected milk, milk fat, and milk true protein were less in CC compared with CT cows by 258, 12, and 10.7 kg, respectively. Cows carrying the TT genotype had increased incidence of displacement of abomasum (4.3%), but genotype did not affect the incidence of retained fetal membranes, clinical and subclinical mastitis, or lameness. Risk of developing at least one clinical health disorder was influenced by leptin genotype, and cows carrying the CT genotype had the lowest risk for developing any disease (19.6%). Mating decisions to increase the frequency of cows heterozygous in the R4C locus may improve productivity and health.

The Italian external quality assessment scheme in classical cytogenetics: four years of activity

BACKGROUND

The Italian external quality assessment scheme in classical cytogenetics was started in 2001 as an activity funded by the National Health System and coordinated by the Italian Public Institute of Health.

OBJECTIVES

The aim of our work is to present data from the first 4 years of activity, 2001-2004.

METHODS

Italian cytogenetics public laboratories were enrolled on a voluntary basis, and this nationwide program covered prenatal, postnatal and oncological diagnosis. The scheme is annual and retrospective; a panel of experts reviewed the quality of images and reports in order to assess technical, analytical and interpretative performance.

RESULTS

Over the 4-year period, the number of participating laboratories increased: from 36 in 2001, 46 in 2002, 49 in 2003 to 51 in 2004. The overall technical performance was satisfactory. Inadequacy or lack of information in reporting was the most frequent analytical inaccuracy identified in all parts of the scheme. However, the percentage of complete reports increased significantly during the period: by 36% in postnatal diagnosis between 2001 and 2004 (p < 0.001) and by 42% in oncological diagnosis between 2002 and 2004 (p = 0.003).

CONCLUSIONS

Our experience reveals that participation in external quality assessment programs has significant advantages, helping to standardize and to assure quality in cytogenetic testing.

Sex chromosome loss, micronuclei, sister chromatid exchange and aging: a study including 16 centenarians

In the present study we analysed the possible effect of age, sex and smoking on the mean values of micronucleus (MN) and sister chromatid exchange (SCE) frequencies on peripheral blood obtained from 38 subjects ranging in age from 16 to 63 years and 16 centenarians. The mean number of binucleated cells with micronuclei varied in function of age and sex (as demonstrated by the analysis of covariance (F=13.13; P<0.001), particularly evident was the increment observed in women with increasing age (interaction age/sex: F=5.53; P<0.05). Smoking habits had no effects on MN frequency (F=0.36; P>0.05). Sex (F=4.18; P<0.05) and smoking habits (F=14.64; P<0.001) influenced significantly SCE per cell frequencies, but age had no effects on them (F=2.45; P>0.05). The age-associated increase of sex chromosome loss was studied using fluorescence in situ hybridisation (FISH) on interphase nuclei. The loss of Y signals was observed in approximately 10% of interphase cells from the centenarians males, that is six times more often than in the younger control men (approximately 1.6%). The frequency of X signal loss (approximately 1.7%) in young women was similar to that observed in male controls of the same age but the incidence of the X chromosome aneuploidy in centenarian females was appreciably higher (approximately 22%) than that found for the Y chromosome in males. These results were correlated with the data on MN formation and a positive correlation between the percentage of aneuploid cells (FISH) and MN values was observed (r=0.50; P<0.05).

Nine novel APC mutations in Italian FAP patients

Familial adenomatous polyposis (FAP) is a common hereditary syndrome characterized by early development of colorectal cancer consequent to extensive adenomatous polyps of the colon. In addition to the colonic manifestations the syndrome presents several extracolonic features including polyps of the upper gastrointestinal tract, congenital hypertrophy of the retinal pigment, jaw cysts, osteomata and desmoid tumors. In this study the entire APC coding region has been analysed for mutation in a panel of one Turcot and 33 unrelated Italian FAP patients using SSCP analysis, PTT and DNA sequencing. We detected APC mutations in 23 of them and identified nine which, to our knowledge were not previously reported. All of these novel mutations are in exon 15, including two nonsense mutations, 6 deletions or insertions leading to premature termination of the protein and one missense mutation (7697G>A). This last mutation occurs in the EB1-binding domain of the APC protein and segregates in four relatives of the patient with three of them presenting 2-3 adenomatous polyps.

Increment of sister chromatid exchange frequencies (SCE) due to epichlorohydrin (ECH) in vitro treatment in human lymphocytes

Although several studies have examined the effects on health of exposure to epichlorohydrin (ECH) through normal industrial operations and production, there is still considerable interest in its potential harmful effects on humans. The aim of the present study was to evaluate ECH effects in vitro through controlled investigations by using sister chromatid exchange (SCE), micronucleus (MN), and chromosome aberrations (CA) as the test battery. Cultures for cytogenetic tests were set up from blood samples of four healthy non-smoking and three smoking males. The experiments were performed using four different concentrations: 10(-10) M, 10(-8) M, 10(-6) M, and 10(-4) M, of ECH in DMSO. Analysis of variance showed that concentrations of ECH had significant effects on SCE/cell frequencies in the lymphocyte cultures of all donors (F=100.25, P<0.001). We were unable to find any evidence of significant increases in CA and MN frequencies in ECH-treated lymphocyte cultures with respect to the controls.

17-alpha-ethinylestradiol and norgestrel in combination induce micronucleus increases and aneuploidy in human lymphocyte and fibroblast cultures

Oral contraceptives are highly efficient and easily administered drugs; however, it must not be forgotten that they are composed of chemical substances which can be classified as potential carcinogens. Testing of a substance for genotoxicity represents a reliable approach both to evaluate the genetic hazard and to obtain information on its possible tumorigenic (cancerogenic) properties. The present study was undertaken to evaluate through carefully planned and controlled investigations the in vitro cytogenetic effects of oral contraceptives (ethynilestradiol and norgestrel mixed in the proportion 1:5) using three different concentrations, with two different durations of treatment (48 and 72 h), on two types of human cells (lymphocytes and fibroblasts) and a series of short-term test procedures: sister chromatid exchange (SCE), micronucleus test (MN), and chromosome aberrations (CA). In addition, the FISH procedure and in vitro anaphase and metaphase preparation analyses were performed. In contrast to CA and SCE frequencies, the frequency of MN in treated blood lymphocytes showed higher values by comparison with the controls, although the difference was statistically significant only for the lowest concentration (P = 0. 016). When using pancentromeric alphoid probes, the FISH procedure gave positive signals in more than 85% of micronuclei, clearly indicating that MN may contain whole chromosomes rather than acentric fragments. Unlike the lymphocytes, the fibroblasts showed dose-dependent effects, although those treated with the highest hormone concentrations showed an increased number of highly damaged cells (cytoplasmatic vacuolization, nuclear fragmentation, etc.), a decreased number of anaphase cells, a large number of which were abnormal, and a reduction of mitotic index. In conclusion, our data confirm that hormones do not induce structural chromosome aberrations in lymphocytes and indicate that ethynilestradiol and norgestrel have an aneugenic effect on fibroblast and lymphocyte cultures; FISH analysis on micronuclei from lymphocyte cultures and anaphase preparations from fibroblast cultures support this hypothesis. Teratogenesis Carcinog. Mutagen. 20:147-159, 2000.

Effect of prostaglandin E(2) on the proliferation, Ca(2+) mobilization and cAMP in HT-29 human colon adenocarcinoma cells

Several lines of evidence suggest that non-steroidal antiinflammatory drugs (NSAIDs) have anticarcinogenic effects. The causal relationship linking the preventive effect of NSAIDs on colon cancer and the inhibition of prostaglandin synthesis is questioned by the contrasting results obtained by many laboratories. The experiments reported in this paper demonstrate that prostaglandin E(2) (PGE(2)) did not stimulate the proliferation in HT-29 human colon adenocarcinoma cells under several experimental conditions. Moreover, PGE(2) and 17-phenyl trinor prostaglandin E(2) (a specific agonist of EP1 receptors) did not increase intracellular Ca(2+) concentration. Finally, PGE(2) did not affect the intracellular cAMP and did not reduce the isoproterenol dependent increase in cAMP. These results indicate that in HT-29 cells: (1) proliferation is not directly sensitive to PGE(2); and (2) PGE(2) does not stimulate a signal transduction pathway leading to intracellular increase in cAMP or Ca(2+) mobilization. Therefore, other cell lines should be used to assess the direct role played by prostanoids in promoting cell proliferation in colon cancer.

Lack of effect by prostaglandin F2alpha on the proliferation of the HCT-8 and HT-29 human adenocarcinoma cell lines

A variety of studies have supported the finding that regular intake of aspirin or non-steroidal anti-inflammatory drugs can affect colorectal cancer carcinogenesis by decreasing the synthesis of prostaglandins (PGs). We report that PG F2alpha, in the presence of indomethacin, did not stimulate the proliferation in HCT-8 and HT-29 human colon adenocarcinoma cells. Moreover, in both cell lines fluprostenol, a specific agonist of FP receptors, did not increase intracellular Ca2+ concentration, monitored with the fluorescent dye fura-2. These results indicate that in HCT-8 and HT-29 cells: i) proliferation is not sensitive to PG F2alpha; ii) functional FP receptors are absent. Therefore, either PG F2alpha is not necessarily involved in the proliferation of colorectal mucosa or cell lines other than HCT-8 and HT-29 should be used to assess the role played by PG F2alpha in promoting cell proliferation in colon cancer.

Two B1 and B2 bradykinin receptor antagonists fail to inhibit the Ca2+ response elicited by bradykinin in human skin fibroblasts

The elevation of intracellular [Ca2+] induced by bradykinin (Bk) was monitored with fura-2 fluorescence in human skin fibroblasts. Neither [des-Arg10][Leu9]kallidin nor D-Arg[Hyp3,Thi5,D-Tic7,Oic8]bradykinin (HOE140) inhibited the Ca2+ response stimulated by Bk. Moreover, each behaved as a partial agonist causing the elevation of intracellular [Ca2+].

STK11 mutations in Peutz-Jeghers syndrome and sporadic colon cancer

A potential tumor suppressor gene, STK11 , encoding a serine threonine kinase, has recently been identified on chromosome 19p13. Germ-line mutations of this gene have been found in patients with Peutz-Jeghers syndrome (PJS). To further investigate the relevance of STK11 mutations in PJS, we analyzed its coding sequence in nine patients and identified two deletions and three missense mutations. Because intestinal carcinomas have been observed to develop in association with PJS, we analyzed tumors from 71 patients for allelic deletions (loss of heterozygosity) and STK11 gene mutations, to elucidate the etiological role of STK11 gene in sporadic colorectal cancer. Loss of heterozygosity, evaluated using the microsatellite D19S886, was observed in 10 of 52 informative cases. No somatic mutations were detected except for a missense alteration in one tumor. Our data indicate the heterogeneity of PJS and the infrequent involvement of the STK11 gene in colorectal cancer.

The familial adenomatous polyposis region exhibits many different haplotypes

In the present study, we used five different polymorphic markers to construct the haplotype at the adenomatous polyposis coli (APC) locus in families with familial adenomatous polyposis (FAP) and in the normal Italian population. Non-ambiguous haplotypes were reconstructed from 246 normal chromosomes and 65 FAP chromosomes. In the control population, the four polymorphisms intragenic to APC gave rise to 16 haplotypes, the most common of which (II and XV) accounted for over 50% of all chromosomes. In FAP patients, 13 haplotypes were found but their distribution was not statistically different from normal subjects. Eighty complete chromosomal haplotypes (many fewer than the theoretical maximum of 208) for the five polymorphic sites assayed were observed in the control population, 35 being found in the FAP patients. We compared the distribution of these haplotypes within the two groups; no statistically significant differences between normal and FAP chromosomes were found. The elevated heterogeneity of FAP chromosomes was clearly confirmed by the observation that 19 patients who carried one or other of the two most common APC mutations (nt 3183 and nt 3927) showed 18 different haplotypes. On the basis of these results, we were not able to identify a founder FAP chromosome. Various mechanisms are presented to explain this observation.

Bradykinin stimulation does not induce intracellular Ca2+ elevation in cells from desmoid tumors

The intracellular mechanisms controlling cell proliferation in desmoid tumors (DT) are unknown. Bradykinin stimulated an increase in [Ca2+](i), (monitored by the fura-2 fluorescence) in fibroblasts obtained from both the skin of a normal donor and the mesenter of a familial adenomatous polyposis (FAP) patient. Cells from DT of the same patient as well as those from another FAP patient failed to show the elevation of [Ca2+](i) usually caused by bradykinin stimulation.

COACH syndrome: report of two brothers with congenital hepatic fibrosis, cerebellar vermis hypoplasia, oligophrenia, ataxia, and mental retardation

Congenital hepatic fibrosis (CHF) is probably the most common cause of non-icteric hepatosplenomegaly and is encountered mainly in children and young adults. We describe here two brothers from healthy, non-consanguineous parents. The patients showed early hepatosplenomegaly, portal hypertension, and no apparent kidney involvement. Clinical and laboratory findings were similar in both patients. Liver biopsies showed the presence of broad septa of fibrous tissue containing abundant bile ducts, portal tracts enlarged by fibrosis, and preserved lobular architecture. The histological findings were suggestive of CHF. Ophthalmological assessment demonstrated visual impairment with mild exotropia, nystagmus, and oculomotor apraxia. Neurological examination showed moderate mental retardation and cerebellar ataxia. Brain MRI confirmed cerebellar malformation with inferior vermis hypoplasia. This pattern of defects is consistent with COACH syndrome (Cerebellar vermis hypoplasia, Oligophrenia, congenital Ataxia, Coloboma, Hepatic fibrocirrhosis) which has previously been reported in five other cases. Our report may contribute to a better delineation of the COACH syndrome phenotype in the spectrum of oculo-encephalohepato-renal disorders.

An unusual dicentric Y chromosome with a functional centromere with no detectable alpha-satellite

We describe an unusual marker chromosome Y. This marker is present in 5% of the lymphocytes of a dysgenetic woman showing a mosaic karyotype 45,X/46,XY/47,XY+mar. Q-banding revealed that the marker was morphologically identical to the Y chromosome of the patient but presented the primary constriction in the heterochromatic region. C-banding confirmed that the heterochromatic region was C-positive; furthermore, it showed two spots in the euchromatic region in a position corresponding to that of the centromere in the normal Y. Fluorescence in situ hybridization with the centromere-specific probe pDP 97 and the pancentromeric alpha-satellite probe alpha 27 alpha 30 failed to detect any signal at the primary constriction site. To improve the characterization of the marker chromosome, hybridization was performed using pDP 105, a probe located on the short arm of the Y chromosome, together with chromosome-Y-specific paint-hybridizing to the single sequence spanning the Y short arm. In both cases, positive signals telomeric to the inactive centromere were observed. Possible mechanisms resulting in the formation of the marker chromosome are discussed.

[Holt-Oram syndrome: cardiological, radiological and genetic evaluation]

A case of a 63-year-old woman with Holt-Oram syndrome is presented. The patient, operated at 38 years for correction of an interatrial defect of the ostium secundum type presented with upper extremity skeletal abnormalities, in particular on the left, and a severe mitral insufficiency with ruptured chordae tendinae of the posterior leaflet. Mitral valve reconstruction was followed by an unusual severe hemolytic anemia and acute secondary renal insufficiency. Valve replacement was therefore necessary. At present, the patient, whose karyotype is normal, is in NYHA functional class I.

Exclusion of the APC gene as the cause of a variant form of familial adenomatous polyposis (FAP)

Familial adenomatous polyposis (FAP) is a premalignant disease inherited as an autosomal dominant trait, characterized by hundreds to thousands of polyps in the colorectal tract. Recently, the syndrome has been shown to be caused by mutations in the APC (adenomatous polyposis coli) gene located on chromosome 5q21. We studied two families that both presented a phenotype different than that of the classical form of FAP. The most important findings observed in these two kindreds are (a) low and variable number of colonic polyps (from 5 to 100) and (b) a slower evolution of the disease, with colon cancer occurring at a more advanced age than in FAP in spite of the early onset of intestinal manifestations. To determine whether mutations of the APC gene are also responsible for this variant syndrome, linkage studies were performed by using a series of markers both intragenic and tightly linked to the APC gene. The results provide evidence for exclusion of the APC gene as the cause of the variant form of polyposis present in the two families described.

Infertility in carriers of two bisatellited marker chromosomes

Two unrelated sterile patients, a male and a female, with karyotypes characterized by the presence of two supernumerary bisatellited marker chromosomes, were studied with the aid of fluorescence in situ hybridization (FISH). Using alphoid centromeric specific probes, the markers were identified as an idic (15) (pter-q11) and a mar (14). In both cases a single accessory bisatellited marker was present in the karyotype of one of the parents. A possible correlation between the excess of constitutive heterochromatin and meiotic disturbances in the two patients is discussed.

Linkage studies in Italian families with familial adenomatous polyposis

Linkage analysis was performed on 188 subjects belonging to 18 Italian families segregating for familial adenomatous polyposis (FAP) using 7 polymorphic markers (5 restriction fragment length and 2 dinucleotide repeat polymorphisms) mapping in 5q21. A two-point linkage analysis performed with the LINKAGE program gave significant lod scores (> 3) between the Pi227, C11p11, YN5.64, YN5.48 probes and the disease, whereas the ECB27, CB83 and EF5.44 markers showed lower lod scores. Some 11 recombination events were identified from the analysis of 101 meioses. The best map that we could determine confirmed that reported in previous studies. The location of the new marker, CB83, lying between YN5.64 and YN5.48, remains imprecise. No genetic heterogeneity was detected, with all the families showing linkage for at least one of the probes. One 34-year-old individual having an affected haplotype was however classified as healthy after clinical examinations. The results confirm the applicability of the linkage approach for presymptomatic diagnosis of FAP.

Familial adenomatous polyposis: identification of a new frameshift mutation of the APC gene in an Italian family

Familial Adenomatous Polyposis (FAP) is a premalignant disease of the gastrointestinal tract inherited as an autosomal dominant trait assigned to chromosome 5q21. The 15 exons of the APC gene responsible for the defect were amplified from the DNA of one FAP patient. SSCP analysis of the amplified DNA revealed a variant conformer of exon 10. The sequencing of the cloned PCR product showed a 1 base insertion at position 1370, creating a stop codon four nucleotides downstream. SSCP analysis of 20 family members and nucleotide sequencing of exon 10 in three affected members confirmed the Mendelian inheritance of the mutant allele.

Cancer family syndrome: cytogenetic investigations, in vitro tetraploidy, and biomarker studies in a large family

Fifty-five members of a family with the cancer family syndrome (CFS) were investigated for the following potential biomarkers for cancer proneness: (1) cytogenetics of peripheral blood lymphocytes and skin fibroblasts; (2) in vitro tetraploidy of dermal fibroblast monolayer cultures; (3) quantitative serum immunoglobulin determinations; (4) study of genetic linkage with respect to eight blood group markers including Kidd. Biological specimens were obtained from 14 patients affected with cancer, 21 subjects at risk, and 20 healthy subjects. None of the markers tested in this family, in order to identify a biomarker for the status of CFS gene carrier, was found to be useful. Our search for linkage to other biological markers (DNA RFLPs and NK cells) is in progress.

Depressed level of natural killer cells in cancer family syndrome

Individuals from kindred with cancer family syndrome (CFS) have an increased genetic risk for the development of adenocarcinoma of the colon as well as of several other organs. Previous studies have suggested that this high occurrence of adenocarcinoma in this as in other hereditary neoplastic syndromes may be correlated to an underlying abnormality in immunological tumor surveillance. In attempt to define a marker that might identify individuals within CFS kindred at risk of developing cancer, we determined natural killer (NK) cell number and NK cell function in affected and healthy members of a CFS family. We studied 13 cancer-affected patients, 20 unaffected but "at-risk" subjects, 20 healthy subjects and 26 normal individuals matched to the patients with colon cancer on the basis of sex and age. We determined the number of NK cells and their function concurrently, using a monoclonal antibody and a 51Cr-release assay with K562 as target cells. We found that the number of NK cells was significantly (P = 0.00004) reduced in cancer patients as compared with healthy subjects and normal controls. Of the 20 at-risk individuals 9 had levels lower than the norm, while 11 showed normal-values. Consequently, the mean percentage of NK cells of this group does not differ either from that of normal subjects or from that of cancer patients. Mean NK cell function was lower in cancer patients than in healthy members of the CFS family but the differences were not statistically significant. Therefore, the mean NK cell function per single cell, expressed as a ratio between cytotoxicity (LU) and the number of NK1-positive cells, resulted paradoxically in an increase when compared with that of normal subjects. The possible mechanisms for this dichotomy were examined.