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P Sala

Publications and source records attributed to P Sala.

At least 19 recordsLinked to original sources
PubMed1998

Age-related persistent clonal expansions of CD28(-) cells: phenotypic and molecular TCR analysis reveals both CD4(+) and CD4(+)CD8(+) cells with identical CDR3 sequences.

In a small group of subjects we had identified persistent expansions (range 6-72%) of CD4(+)CD8(+) double-positive (DP) peripheral blood (PB) cells which express the CD8 alpha/alpha homodimer. Here, DP cells present in a larger cohort were further investigated and found by FACS analysis to express a single or a dominant TCRBV family. In these subjects, with a mean age of about 64 years, expansions of CD4(+) cells with the same TCRBV family specificity as in the respective DP cells also were consistently detected. TCR heterogeneity of the dominant TCRBV family was specifically evaluated: The amplified CDR3 region was cloned and found to consist of one single or two largely dominant sequence patterns. Furthermore, cloning of the CDR3 region from FACS-sorted DP, CD4(+), or CD8(+) cells indicates that both DP and CD4(+), but not CD8(+) cells, isolated from the same individual possess a striking identity of the CDR3 regions. As indicated by FACS analysis, the clonally expanded cells occur in the CD4(+)CD28(-) cells. Taken together, these results suggest that expanded CD4(+)CD28(-) cells might also acquire CD8 alpha/alpha expression and become DP and imply that CD4 clonality is a more frequent phenomenon than previously suspected. In conclusion, the persistent expansions described in this report represent a novel group of age-related benign clonal expansions of still undefined significance of a rare CD28(-) T cell subset.

Adult↗
PubMed1998

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.

Adenomatous Polyposis Coli↗
PubMed1998

Mutations of adenomatous polyposis coli (APC) gene are uncommon in sporadic desmoid tumours.

Desmoids are locally aggressive, non-metastasizing soft-tissue tumours, whose aetiology is still unclear. In patients affected with familial adenomatous polyposis (FAP), the incidence of desmoids is much higher than in the general population. The APC gene, which is responsible for FAP, is involved in the development of desmoids associated with this syndrome. In this study 16 sporadic and four FAP-related desmoids were analysed in order to investigate the possible involvement of APC in non-syndromic cases also. The 5' end (exons 1-11) and the coding portion of exon 15 of APC were screened using the in vitro synthesized-protein assay (IVSP). Exons 5, 6, 8-14, and a region of exon 15 spanning codons 1036-1634 were investigated by single-strand conformation polymorphism (SSCP) analysis. APC germline mutations were identified in all FAP patients, but not in sporadic cases. Somatic mutations were found in three FAP-associated desmoids (75%) and two sporadic tumours (12.5%). In one of the latter cases, both alleles were affected. These findings indicate a limited role of the gene in the development of desmoid tumours outside FAP.

Adenomatous Polyposis Coli↗
PubMed1998

Chain-terminating mutations in the APC gene lead to alterations in APC RNA and protein concentration.

APC mutations introduce premature stop codons into the open reading frame of the gene, leading to the formation of truncated tumor suppressor proteins. Both RNA and protein levels are likely to be profoundly altered by such nonsense mutations. To test this hypothesis, Western blotting and RT-PCR strategies were used to characterize mutant and normal APC protein and APC RNA concentrations in lymphoblastoid cell lines from 22 unrelated polyposis patients carrying different APC mutations. Variable levels of truncated APC peptides were observed in 14 of 14 cell lines with APC mutations within exon 15. No truncated APC protein was detected in six of eight cell lines with APC mutations located 5' of exon 15. Mutations located in exon 15 showed mutant RNA underrepresentation in four of eight cell lines, whereas mutations located 5' of exon 15 showed RNA reduction in five of six cell lines. These findings indicate that a two- to threefold decrease in RNA concentration is common when APC alleles carry chain-terminating mutations. They also suggest that the severe decrease of truncated APC protein observed in some cell lines is due to mechanisms acting at the protein level.

Adenomatous Polyposis Coli Protein↗
PubMed1997

US imaging and color Doppler in patients undergoing inhibitory therapy with calcitriol for secondary hyperparathyroidism.

The aim of this study was to evaluate the changes in volume, structure, and flow pattern of parathyroid glands in uremic patients with secondary hyperparathyroidism treated with long-term intravenous calcitriol (CTL) therapy. Ultrasonography was used to follow-up volume changes occurring in 18 enlarged glands in 11 patients during an 18-month period; in 6 of these cases, 11 glands were followed-up also with color-Doppler to monitor variations in flow pattern. Vascularization was classified using three grades: grade 0 = no color signal; grade I = vessels covering less than 50 % of glandular cross-sectional area; grade II = vascular signals covering more than 50 % of glandular cross-sectional area. No significant changes in volume were demonstrated during the 18 months of follow-up. On the contrary, significant decrease in flow was observed with almost complete disappearance of color-Doppler signals. This finding related well with the observed decrease in parathormone blood levels. Lack of volume changes during medical therapy demonstrates the inability of US alone to monitor the effect of this treatment on the parathyroid glands. Conversely, the observed intraglandular flow reduction indicates the possibility to use color Doppler to monitor the effects of CLT in uremic hemodialyzed patients with secondary hyperparathyroidism. This imaging procedure can be proposed for follow-up of the response of the parathyroid glands to therapy.

Blood Flow Velocity↗
PubMed1997

Mean age of tumor onset in hereditary nonpolyposis colorectal cancer (HNPCC) families correlates with the presence of mutations in DNA mismatch repair genes.

Fourteen Italian families affected with hereditary nonpolyposis colorectal cancer (HNPCC) were screened for germline mutations at three DNA mismatch repair (MMR) genes, MSH2, MLHI, and GTBP, by using a combination of different methods that included an in vitro synthesized protein assay, single-strand conformation polymorphism analysis, and direct sequencing. DNA alterations were observed in six instances, including a single base deletion in MSH2 exon 14, an A-to-G transition in the splice donor site of MLHI exon 6, and two missense mutations in MLHI exons 5 and 9. A previously reported common mutation affecting the splice donor site of MSH2 exon 5 was identified in two families. No mutations were detected in the GTBP gene. In total, eight of 16 Italian HNPCC families (50%), including two previously reported kindreds, were found to carry a mutation in MMR genes. We compared the mean age of colorectal cancer onset in the index cases (three patients for each family) between the two groups of kindreds, those with identified mutation vs. those without, and found that the first had a significantly lower value (43.0 vs. 53.7 years, P = 0.014). This finding suggests that HNPCC families with a more advanced age of tumor onset are less likely to be associated with known MMR genes.

Adaptor Proteins, Signal Transducing↗
PubMed1996

Molecular screening of families affected by familial adenomatous polyposis (FAP).

OBJECTIVES: To assess the risk of developing familial adenomatous polyposis (FAP) in presymptomatic individuals using APC gene flanking and intragenic polymorphic markers. SETTING: Twenty families enrolled in the Italian Registry of Polyposis comprising a total of 217 individuals, including 53 (24%) presymptomatic subjects with a 50% a priori risk of FAP, were analysed. Direct analysis techniques had previously failed to identify the FAP mutation in these families. METHODS: DNA isolated from peripheral mononuclear blood cells and tissue sections was analysed by the polymerase chain reaction and a panel of seven highly polymorphic markers--YN5.64, CB83, CB26, LNS, APC1458.5, MBC, 37AB. Amplification products were separated by a modified denaturing gel electrophoresis method. RESULTS: The haplotype associated with the disease was identified in 18 families (90%). The segregation of the FAP haplotype in these kindreds showed that 10 presymptomatic individuals had inherited the FAP mutation and carried a high risk of developing the disease. The remaining two families were not informative because of the lack of a sufficient number of probands or biological specimens. CONCLUSIONS: These data indicate that indirect analysis with linked DNA markers has a high rate of success in defining the risk of FAP of presymptomatic subjects, provided that a sufficient number of probands or samples is available. Uninformative families accounted for 10% of the total, indicating that linkage analysis may still have higher sensitivity than direct mutation analysis techniques. The combined use of both approaches should be implemented, however, to enhance further the application of molecular genetics to the screening of families with FAP.

Adenomatous Polyposis Coli↗
PubMed1996

[Pain in the lower extremities after subarachnoid block with lidocaine].

Subarachnoid block is a widely practiced anesthetic technique. With the availability of small-diameter needles and the rises in out-patient surgery, the number of procedures performed with subarachnoid block and short-term local anesthesia have increased. We report two cases of bilateral pain in the lower extremities appearing 20-24 h after intradural anesthesia with 2% hyperbaric lidocaine. We analyze the factors that might have triggered this complication and compare the two patients with 14 others described in the literature. Three points in common were found: the use of hyperbaric lidocaine, administration of the agent through small gauge needles and the performance of out-patient surgery.

Adult↗
PubMed1995

Epidemiology of hepatitis D virus infection: changes in the last 14 years.

To calculate the prevalence of hepatitis D virus (HDV) superinfection, antibody to HDV (anti-HD) was tested on admission in 696 hepatitis B virus (HBV) chronic carriers diagnosed between 1979 and 1992. Anti-HD was positive in 67 patients (9.6%), and it was more frequently detected in i.v. drug abusers (IVDA) (59/74, 79.7%) than in non-IVDA (8/622, 1.3%) (p = 0.0001). The prevalence of anti-HD was higher in HBV chronic carriers diagnosed between 1979 and 1985 (33/219, 15.1%) than in those diagnosed from 1986 to 1992 (34/477, 7.1%) (p < 0.001). However, these figures were not different when IVDA were analyzed alone; 29/34 (85%) and 30/40 (75%) (p = 0.4) IVDA diagnosed in both time frames were anti-HD-positive. Four hundred and thirty anti-HD-negative HBV carriers were prospectively followed, and serial determinations of anti-HD were made. Seroconversion to anti-HD was observed in only six patients (1.4%), and again the rate of seroconversion was higher in IVDA (5/10, 50%) than in non-IVDA (1/420, 0.2%) (p < 0.0001). These findings show that IVDA HBV chronic carriers are still an extremely high risk group for HDV superinfection in Spain and that this virus has little penetrance in other epidemiological categories of HBV carriers.

Adult↗
PubMed1994

[Blood donors with positive HBsAg in Asturias: its current prevalence and significance].

BACKGROUND: The aim of the present study was to know the current prevalence of HBsAg positivity in Asturias blood donors and to carry out a clinical study of the carriers of the hepatitis B virus (HBV) accidentally detected in a blood donation program. METHODS: A prospective study of incidence and prevalence of HBsAg positivity in blood donations performed in Asturias over two years from October 1989 and 1991 was carried out and the epidemiologic, clinical, and analytical characteristics, as well as histologic liver lesions in the HBsAg positive cases were determined. RESULTS: Among the 42,789 blood donors during this above mentioned period in Asturias 119 cases of HBsAg positivity were found, representing a prevalence of 0.16% of the donations and 0.28% of the donors, generally new donors (95.8%) with a prevalence of 1.2% in this subgroup. No risk factors or known source of contagion were found in 43.6% of the cases and in most occasions the donors were asymptomatic HBsAg carriers (96.5%) with normal transaminases (87.3%) with 4.6% of the cases being HBeAg positive and 3.5% being mutant "e minus" carriers. CONCLUSIONS: The prevalence of HBsAg was almost limited to new donors with a higher prevalence being observed with respect to other regions. Most of the cases may be considered as "apparently healthy" and in the group with positive replicative markers a similar number of positive HBeAg carriers and "e minus mutants" were present.

Adolescent↗
PubMed1994

Phenotypic heterogeneity of persistent expansions of CD4+ CD8+ T cells.

A group of 18 individuals is described that manifest persistent (follow up between 4 and 57 months) expansions (ranging from 10 to 70%) of CD4+ CD8+ peripheral T cells. In nine individuals there was no apparent underlying disease whereas the remaining displayed a wide range of unrelated diseases. Analysis of the cell surface immunophenotype showed that all individuals express high densities of CD2, CD3, CD5, and TCR alpha/beta on their CD4+ CD8+ subset. On the contrary, these cells did not express CD25, CD38, CD71, HLA-DR, and the beta chain of the interleukin-2 receptor (p75) but expressed high density of CD29 and low density or absence of CD7. CD8 was "dim" in most individuals and consisted only of the CD8 alpha chain isoform. These individuals could be further divided into two subgroups based on the following parameters: in eleven cases CD4+ CD8+ cells had an LGL morphology and expressed the CD11b, CD56 and CD57 NK-associated antigens; in addition, a high percentage of CD4+ CD8- cells from the same individuals also expressed NK-associated antigens on their cell surface (subgroup A). The CD4+ CD8+ cells of the remaining individuals had small lymphocyte morphology, expressed little or no CD11b and CD56 and their CD4+ CD8- cells did not express NK-associated antigens at all (subgroup B). Finally, CD8 was "bright" on the CD4+ CD8+ cells of three individuals and in these cells also the CD8 beta chain isoform was present (subgroup C). Southern blot hybridization of genomic DNA with a T-cell receptor beta probe revealed that of the sixteen individuals examined four had a monoclonal, seven an oligoclonal, and five a polyclonal molecular configuration. The present data indicate that persistent CD4+ CD8+ expansions represent a novel heterogeneous subset of T cells.

Adult↗
PubMed1994

Mutation in a splice-donor site of the APC gene in a family with polyposis and late age of colonic cancer death.

Adenomatous polyposis coli (APC) is an autosomal dominant disease characterized by the development of hundreds of colorectal adenomatous polyps during the first decades of life. The expression of the disease varies, as the age of onset of colonic cancer and the severity of extracolonic manifestations often differ between affected families. An attenuated form of APC has also been described in which a small number of polyps and a later age of onset of colonic cancer is observed. Cloning of the APC gene has allowed disease-causing mutations in APC families to be identified. Here, we report a novel splice site mutation (a G to T transversion at position +5 of the splice donor site in intron 9) in the APC gene of affected individuals in an Italian family. Characterization of the transcription products from this mutant APC allele revealed that normal splicing was disrupted: a shorter mRNA was expressed in which exon 8 was connected directly to exon 10. This created a shift in the reading frame and the introduction of a stop codon at position 1358. In addition, some normal APC transcript was produced from the mutant allele in lymphoblastoid cells. A comparison of the clinical features of affected members of this family with four unrelated Italian APC kindreds, in which the same AAAAG deletion at position 3926 has been found, showed a significant difference in the onset of disease symptoms and in the age of death attributable to colorectal cancer. Inefficient exon skipping may be, at least in part, responsible for the delay in the development of the disease in the reported family.

Adenomatous Polyposis Coli↗
PubMed1994

Comparative analysis of results of guaiac and immunochemical tests for faecal occult blood in colorectal cancer screening in two oncological institutions.

The performances of three faecal occult blood tests, rehydrated Hemoccult (HOR), Hemoccult sensa (HOS) and Hemeselect (HSEL) on 3 days were compared in 1,725 subjects consecutively recruited in two oncological institutions in Milan and Florence. Significant differences between the results were evident as far as HOR positivity rates (7.5% vs 4.0%, respectively) and specificity (94.3% vs 97.5%, respectively) are concerned. Overall positivity rates of HOR, HOS and HSEL were 5.9%, 5.4% and 12%, respectively; significant differences were evident between HSEL and each of the two guaiac tests. Cancer was detected in eight subjects, adenoma/s in 47. Specificity estimates were 95.8%, 90.2% and 90.5% for HOR, HOS and HSEL, respectively; significant differences were evident between HSEL and the other two tests. No significant difference between tests was evident for sensitivity or positive predictive values for cancer or adenomas. In the CSPO (Florence) population (1,223 subjects; five with cancer, 16 with adenoma/s) the performances of 1-day HSEL testing were determined on the basis of the first faecal sample only and compared with 3-day HOR, HOS and HSEL testing. The positivity rates of 1-day HSEL, 3-day HOR, HOS and HSEL testing were 7.0%, 5.0%, 5.5% and 12.9%, respectively. Only 3-day HSEL positivity rate was significantly higher than 1-day HSEL. One-day HSEL specificity (94.9%) was significantly higher than 3-day HSEL (90.0%), whereas no significant difference was seen between 1-day HSEL, HOR (96.5%), and HOS (96.1%) specificity. No significant difference between tests is evident in the CSPO population as far as positive predictive values and sensitivity for cancer and adenomas are concerned.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1994

Age of onset in familial adenomatous polyposis: heterogeneity within families and among APC mutations.

Heterogeneity among and within FAP pedigrees for the age of symptom onset and the age at death from colorectal cancer was studied in a sample of 583 patients of the Italian Polyposis Registry. The among pedigree variation was largely explained by clustering of families in two groups, 'early FAP' (most colorectal cancer deaths below 45 years of age) and 'late FAP' families (most deaths above age 45). The within-family variation was explained by a marked phenomenon of anticipation (15 years per generation, on the average), possibly not due to ascertainment bias. We then considered the pedigrees with identified mutation in the APC gene. Six families shared a common deletion at codon 1309 and showed the early FAP phenotype. Two families shared a mutation at codon 1061 and revealed the late FAP phenotype. Another two families (codons 453 and 302) clustered with the late FAP group, whereas a family with mutation at codon 835 clustered with the early FAP group. We suggest that there are at least two classes of mutations in the APC gene with different consequences at the phenotypic level. It seems that there are several critical points within the APC protein sequence at which truncation causes a more aggressive disease than truncation at other points.

Adenomatous Polyposis Coli↗
PubMed1993

Persistent expansions of CD4+ CD8+ peripheral blood T cells.

CD4+ CD8+ cells are present during T cell differentiation in the thymus. Less than 2% of normal T cells that coexpress CD4 and CD8 also are released in the circulation and are present in the peripheral blood. In this study, nine individuals are described that manifested persistent expansions (11% to 43%) of circulating CD4+ CD8+ T cells that in three cases had large granular lymphocyte (LGL) morphology in the absence of either lymphocytosis or overt lymphoproliferative disorders. Southern blot hybridization of enriched CD4+ CD8+ cells with T-cell receptor beta (TCR beta) and TCR gamma probes showed that most cases had the 12-kb Eco RI germinal band deleted or of decreased intensity. In several individuals new TCR beta-specific bands of different intensity and distinct from case to case suggested either monoclonal or oligoclonal and polyclonal expansions. Immunophenotypic analysis showed that in 7 out of 9 cases the CD4+ CD8+ T cells presented with CD8 dim expression. Furthermore, all the CD4+ CD8+ cells did not express many of the known activation antigens (low or absent CD25, CD38, CD71, HLA-DR), whereas they expressed high levels of CD2, CD29, CD56, and CD57. In addition, the CD4+ CD8+ cells of 5 out of 9 subjects coexpressed CD45RA and CD45RO suggesting that these cells might be "frozen" in an intermediate state between naive and memory T cells. In conclusion, the present CD4+ CD8+ cases fall within a larger spectrum of disorders ranging from apparently normal to reactive or proliferative situations and encompassing cells with LGL morphology or LGL-associated antigens expression either in the presence or in the absence of absolute lymphocytosis that deserve careful follow-up investigations.

Adult↗