„Sú kemur tíð, er sárin foldar gróa“. Upphafsár skógræktar og sandgræðslu á Íslandi.

Fjallað er um aðkomu danskra manna að skógrækt og sandgræðslu á upphafsárum þessara málefni á Íslandi og fyrsta skógræktarstjórann sem var danskur, Agner F. Kofoed-Hansen

Loss of heterozygosity on chromosome 9 in human breast cancer: Association with clinical variables and genetic changes at other chromosome regions

Primary breast tumors were tested for loss of heterozygosity (LOH), on chromosome 9p with microsatellite markers restricted to a 28 cM region including the MTSI gene. LOH was found with at least I marker in 38% of the 201 cases analyzed. A high frequency of deletions was detected at the 9p23-p21 region, indicating a tumor suppressor gene(s) important for breast cancer tumorigenesis. Tumors with and without LOH on 9p were compared with respect to clinico-pathological factors using chi(2) analysis. Tumors with 9p LOH were significantly associated with high S-phase status and aneuploidy, but not with type, node status, estrogen and progesterone receptor content or age of the patients at diagnosis. Survival analysis showed that LOH at 9p did not significantly affect the survival rate of breast cancer patients. Our results indicate that the aberrations on 9p detected in this study are not of independent prognostic value. A significant association was found between LOH at 9p and LOH at chromosomal arms 3p and 6q, which is an additional contribution toward understanding the genetic events in breast tumor pathogenesis.This work was financially supported by the Nordic Cancer Union, the Icelandic Cancer Society, the University of Iceland Research fund, the Memorial Fund og Bergthora Magnusdottir and Jakob B. Bjarnason, the Science Fund of Iceland, the Science Fund of the University Hospital of Iceland and the Nordic Council of Ministers

Mapping of chromosome 3 alterations in human breast cancer using microsatellite PCR markers: Correlation with clinical variables

Human breast tumours were analyzed with polymorphic microsatellite markers specific to chromosome 3p. Allelic imbalance (AI) was observed in 34% of the tumours. Microsatellite markers from two regions showed higher percentage of imbalance suggesting the presence of tumour suppressor genes or genes important for malignancy. Microsatellite instability was also found, implying errors in DNA replication. No significant correlation was found between AI and conventional prognostic variables. However, a striking correlation was found between AI and tumour S-phase fraction; AI was also significantly correlated with low steroid receptor content. A multivariate model including prognostic variables, showed that AI was without exception a significant prognostic variable; patients having tumours with AI had approximately a four-fold increase in relative risk of death. We conclude that screening for 3p deletions gives prognostic information and further investigations should reveal whether this finding could assist in treatment of the disease.This work was financially supported by the Nordic Cancer Union, Icelandic Cancer Society, The University of Iceland Research Fund, the Memorial Fund of Bergthora Magnusdottir and Jakob B. Bjarnason, the Science Fund of Iceland and the Science Fund of the University Hospital of Iceland. The Nordic primer bank in Uppsala, Sweden, is supported by the Nordic Council of Ministers

Mapping loss of heterozygosity at chromosome 13q: Loss at 13q12-q13 is associated with breast tumour progression and poor prognosis

Several chromosome regions exhibit loss of heterozygosity (LOH) in human breast carcinoma and are thought to harbour tumour suppressor genes (TSG). At chromosome 13q, two TSGs have been identified, RB1 at 13q14 and BRCA2 at 13q12-q13. In this study, 139 sporadic breast tumours were analysed with 18 polymorphic microsatellite markers for detailed mapping of LOH at chromosome 13q and evaluation of an association with known progression factors. LOH with at least one marker was observed in 71 (51%) of the tumours analysed. The deletion mapping indicated three LOH target regions, 13q12-q13, 13q14 and 13q31-q34. LOH at chromosome 13q12-q13 was associated with low progesterone receptor content, a high S phase fraction and aneuploidy. Multivariate analysis adjusting for lymph node involvement and S phase fraction showed that patients with tumours exhibiting LOH at 13q12-q13 have a 3-4-fold increased risk of recurrence and death compared with other patients. Our results suggest there are at least three separate LOH target regions at chromosome 13q and inactivation of one or more genes at chromosome 13q12-q13 results in poor prognosis for breast cancer patients.This work was financially supported by the Research Fund of the University of Iceland, the Nordic Cancer Union, Icelandic Cancer Society, Memorial Fund of Bergthora Magnusdottir and Jakob B. Bjarnason, the Research Council of Iceland and the Science Fund of the University Hospital of Iceland