Biomedical subjects

F Mertens

Publications and source records attributed to F Mertens.

At least 199 records · Page 11Linked to original sources

PubMed1989

In vivo induction of A/J anti-ARS responses with different ranges of affinities: correlation between affinity and CRIA idiotype dominance.

The anti-ARS immune response of A/J mice is characterized by the reproducible and dominant selection of CRIA bearing antibodies. In this report, we have investigated the role of affinity for the antigen in the selection of antibody repertoire during an immune response. A/J anti-ARS responses with different ranges of affinities for arsonate were elicited by the injection of differently arsanylated carrier proteins. The selection of higher affinity A/J anti-ARS responses was shown to be associated with the induction of higher levels of CRIA bearing anti-ARS antibodies. A detailed idiotopic analysis also showed a more precocious selection of the CRIA "canonical combination" in the higher affinity anti-ARS responses. These results strongly suggest an important role for affinity and clonal selection in the dominant expression of the CRIA idiotype in the A/J anti-ARS response.

Animals↗

PubMed1989

Constitutional chromosome instability and cancer risk.

Acquired, clonal chromosome abnormalities are thought to be of pathogenetic importance in human cancer; at the cellular level, neoplasia is best viewed as a genetic disease. It is therefore logical to suggest that cancer risk must somehow be related to individual variations in genomic stability. Those persons whose chromosomes are less stable will, on average, be the ones who are most likely to develop cancer. The testing of this hypothesis shows that, apart from the autosomal recessive chromosome breakage syndromes, only patients with adenomatosis of the colon and rectum have, consistently and by different groups, been found to display elevated spontaneous and clastogen-induced chromosome breakage frequencies. Some evidence indicates a similar tendency in patients with dysplastic nevus syndrome, basal cell carcinoma, cervix cancer, and Kaposi's sarcoma. For several other cancers the data strongly argue against any inherent genomic instability. Although most results thus fail to support constitutional chromosome fragility as a factor of importance in tumorigenesis, conclusive falsification of the hypothesis cannot be said to have been obtained. The possibility remains that variations in chromosome stability and clastogen sensitivity between different cell types, and also difficulties in selecting the most appropriate carcinogens in clastogen-exposure tests, may have masked systematic constitutional differences between patients and controls in the breakage assays.

Chromosome Aberrations↗

PubMed1989

Chromosome abnormalities in a pancreatic adenocarcinoma.

Short-term cultures initiated from a pancreatic adenocarcinoma were cytogenetically investigated. The composite karyotype was 74-76,XX,+X,+2,+3,+del(3)(p21),+5,+5,+der(7) t(1;7)(q21;p22),+der(7),del(8)(p21),+del(8)(p21),+der(8)t(8;?)(q24; +),+9,+9,+10,+10,+11,+11,+12,+13,+14,+der(14)t(14; +)(p11;?),+der(16)t(15;16)(q11;p13),+der(16),+der(17)t(17;?) (p11;?),+der(17),+18,+20,+20,-21,-21,+22,+22,+1-3mar. A comparison with the few previously cytogenetically characterized cases of this tumor type reveals no consistent abnormalities.

Adenocarcinoma↗

PubMed1989

Basosquamous papilloma. A benign epithelial skin tumor with multiple cytogenetic clones.

Cytogenetic analysis of short-term cultures from a basosquamous papilloma revealed the following mosaic karyotype: 46,XX,t(2;5)(q31;q31),t(8;15)(p21;q21)/46,XX,t(7;17)(p13;p13)/47,XX, t(3;20)(q12;p13),+7/46,XX,t(1:12)(p12;q13). The finding of four abnormal, cytogenetically unrelated clones suggests a multicellular origin of this benign skin tumor. None of the structural rearrangements encountered have previously been associated with neoplasia.

Aged↗

PubMed1989

Clonal chromosome aberrations in a keratoacanthoma and a basal cell papilloma.

Clonal chromosome abnormalities were found in short-term cultures from two epithelial skin tumors, a basal cell papilloma and a keratoacanthoma. The three-way translocation t(2;6;11)(q21;q27;p13) was the sole clonal rearrangement in the basal cell papilloma. The karyotype of the keratoacanthoma was more complex: 46,XX,der(2)(2pter----2p13::2p11----cen----2q37: :5q33----5qter),der(2) (:2p13----cen----2q37::6q23----6qter),der(5)t(2; 7;5)(q37;q11;q33),der(6) (6pter----cen----6q23::2p13----2pter),der(7)t(2; 7;5)(q37;q11;q33), del(13)(q11q14). In addition, several nonclonal structural changes were seen in both tumors.

Aged↗

PubMed1989

Diverse chromosome abnormalities in squamous cell carcinomas of the skin.

Short-term cultures from three invasive squamous cell carcinomas of the skin were cytogenetically analyzed. Clonal chromosome aberrations were found in all tumors. In the first case, two of three abnormal clones were related, and in the second case, two of five clones demonstrated cytogenetic similarities. Both clones detected in case 3 had a structural rearrangement in common. Several nonclonal changes were seen in all three cases in addition to the clonal aberrations. None of the rearrangements detected, clonal or nonclonal, corresponds to any of the consistently cancer-associated aberrations known from other neoplasms. The remarkably diverse karyotypic picture of the three squamous cell carcinomas, in particular the finding of unrelated clones in two of them, hints that these neoplasms may be poly-rather than monoclonal. The lack of a common cytogenetic denominator argues that if chromosomal changes are of pathogenetic importance in this tumor type, a wide variety of apparently dissimilar changes exist that are roughly equal in their capacity to malignantly transform skin epithelium.

Aged↗

PubMed1988

Normal frequency of chromosome breakage in lymphocytes from patients with musculoskeletal sarcoma.

Spontaneous chromosome aberrations were studied in lymphocytes from 23 untreated patients with musculoskeletal sarcoma and 27 controls. Among the sarcoma patients, the mean gap, break, and gap + break events per 100 metaphases were 0.9, 2.2, and 3.0, respectively. The corresponding values for the control group were 1.3, 1.6, and 2.8. The mean number of aberrant mitoses was 2.4% in the sarcoma group and 2.5% in the controls. None of the differences between patients and controls were statistically significant. Thus, we found no evidence of inherent chromosome instability in patients with malignant mesenchymal tumors.

Adolescent↗

PubMed1988

Normal level of spontaneous chromosome breakage in lymphocytes from patients with non-Hodgkin's lymphoma.

The frequency of spontaneous structural chromosome aberrations was studied in phytohemagglutinin-stimulated lymphocytes from 25 untreated patients with non-Hodgkin's lymphoma and 25 controls. In the lymphoma group, the mean gap, break, and gap + break event frequencies (i.e., events per 100 cells) were 1.2, 2.1, and 3.4, respectively. The corresponding rates for the control group were 1.3, 1.5, and 2.8. The mean number of aberrant mitoses per 100 mitoses were 2.5 in lymphoma patients and 2.4 in controls. These differences between patients and controls were not significant (p greater than 0.05). Thus, no evidence of inherent chromosome instability or exposure to clastogenic agents in the lymphoma group was detected.

Adult↗

PubMed1988

Duplication 18p with mild influence on the phenotype.

Duplication 18p was found in a 12-year-old girl whose father carried a balanced translocation involving the same chromosome segment, t(18;21)(p11;p11). Our patient had delayed speech development, mild psychomotor retardation, epilepsy, and minor anomalies, including a low nasal bridge, anti-mongolian eye slant, low-set ears, and narrowly arched palate. These findings are compared with eight previously published cases.

Child↗

PubMed1988

Bands involved in primary chromosome rearrangements in sarcomas are not constitutionally liable to breakage in sarcoma patients.

The localization of breakpoints in spontaneous chromosome aberrations, i.e., chromatid and chromosome gaps, breaks, and exchanges, has been studied in cultured skin fibroblasts from 34 untreated patients with musculoskeletal sarcoma and 38 controls. A total of 325 aberrations in the sarcoma group and 251 in the control group could be assigned to particular bands. The distribution was non-random (P less than 0.001) in both groups. Twenty-one bands in the sarcoma group and 20 in the control group appeared as hot spots, with 11 represented in both groups. Only three hot spots, all of which were present among both patients and controls, coincided with bands involved in primary sarcoma-associated chromosome rearrangements. The results indicate that the chromosome breakage pattern of non-malignant cells is similar in sarcoma patients and controls. Hence, the occurrence of primary structural rearrangements in sarcomas cannot be accounted for by any constitutional proneness to chromosome breakage at these bands.

Adult↗

PubMed1988

No increased chromosome breakage in skin fibroblasts from patients with musculoskeletal sarcoma.

The frequency of structural chromosome aberrations was studied in cultured skin fibroblasts from 25 untreated patients with musculoskeletal sarcoma and 25 controls. Subepidermal skin biopsies from the sarcoma patients were taken either close to the tumor (10 patients), at a distance from the tumor, i.e., from a contralateral limb (8 patients), or from both sites (7 patients). The aberration frequencies in fibroblasts obtained from different locations did not differ significantly (P greater than 0.05). The two groups of fibroblast lines were therefore pooled, yielding a total of 25 sarcoma patients with the following mean frequencies of aberrant cells, and gap, break, and gap + break events: 5.3, 2.8, 3.2, and 6.1. Among the controls the corresponding rates were 5.1, 2.6, 3.2, and 5.8. The differences were not statistically significant. These results provide no evidence of local differences in chromosome aberration frequencies, or that inherent chromosomal instability is important for the pathogenesis of sarcomas.

Bone Neoplasms↗

PubMed1988