Search PubMed⌕ Search

Biomedical subjects

G Tanum

Publications and source records attributed to G Tanum.

30 records · Page 2Linked to original sources
PubMed1990

Benzylidene-glucose: no effect after all?

Several promising reports on the treatment of human cancer with various benzaldehyde derivatives have been published during the last decade. The present phase II study was performed to investigate whether the rather sensational results of one such derivative, benzylidene-D-glucose (BG), could be confirmed. The study included 14 patients with metastases from adenocarcinomas of the colon and rectum. The patients were treated with BG according to the recommended regimen for 8 weeks, after which tumor response was evaluated. Neither clinical tumor regression nor side effects were observed. The present study does not confirm the extremely good results previously reported by others. We conclude that BG is not an active agent in colorectal cancer.

Adenocarcinoma↗
PubMed1988

Small megakaryocytes--an identification problem.

The number of bone marrow megakaryocytes (MK) was estimated in May Grunwald-Giemsa-stained (MGG) and immunoenzymatically stained smears. The latter was performed after incubation with a monoclonal antibody (ITI-PL1) directed against blood platelets and megakaryocytes (MK). The MK were grouped according to their size (diameter above or below 30 micron, respectively). Altogether 7.9% more MK were recognized in ITI-PL1 stained smears as compared to MGG-stained smears, mainly because comparatively few small MK were recognized in MGG-stained smears.

Antibodies, Monoclonal↗
PubMed1987

The effect of pretreatment with thio-TEPA and cytosine arabinoside on megakaryocytopoiesis in rats given a sublethal dose of thio-TEPA.

The present study was performed on rats, mainly to examine the so-called priming effect on megakaryocytopoiesis. One group of animals received 2 or 4 mg thio-TEPA or 200 mg cytosine arabinoside/kg body weight (the pretreatment) 2.5 days or 8 days prior to a dose of 10 mg thio-TEPA/kg body weight (the challenge dose). Another group received a pretreatment dose of 1 mg melphalan/kg body weight 2.5 days prior to a challenge dose of 3 mg melphalan/kg body weight. The number of bone marrow megakaryocytes, blood platelet production, mean platelet volume, blood platelet counts, leucocyte and granulocyte counts were examined on days 2, 4, 7, 10, 13, 16 and 20 after the challenge dose. The gut mucosa (number of mucosal crypts in terminal jejunum) and survival were studied in animals receiving pretreatment 2.5 days prior to a challenge dose of about LD100 for thio-TEPA and melphalan. No systematic differences were observed whether the animals received pretreatment prior to the challenge dose or not. Thus, no priming effect was observed.

Animals↗
PubMed1986

Megakaryocyte DNA content and platelet formation in rats after a sublethal dose of thio-TEPA.

The megakaryocytopoiesis in rats was studied following a single dose of thio-TEPA to determine the mechanisms for the thrombocytopenia and subsequent recovery. The blood platelet number, platelet production (measured by 35S incorporation into platelets), mean platelet volume, and the number and DNA content of bone marrow megakaryocytes (MK) were observed. The blood platelet counts, platelet production, and total MK number decreased to low values following the administration of thio-TEPA, and stayed low until regeneration started around day 10. The mean platelet volume increased from the normal 6.6 fl to 7.8 fl during the early regeneration days 8-14. The MK were divided into four ploidy classes: 2N-4N, 8N, 16N, and 32N-64N. The number of MK within all ploidy classes decreased to nearly zero within four days after the injection of thio-TEPA. The regeneration started around day 10 with increasing numbers of 2N-4N and 8N MK, while the number of 16N and 32N-64N MK increased more than four days later. It is concluded that decreased or blocked influx of progenitor cells into the MK compartment is the main reason for thrombocytopenia after exposure to thio-TEPA.

Animals↗
PubMed1984

The megakaryocyte DNA content and platelet formation after the sublethal whole body irradiation of rats.

The DNA content of rat bone marrow megakaryocytes (MK) was studied by Feulgen photometry, following whole body irradiation with 2 Gy. The DNA measurements were preceded by acetylcholinesterase staining to avoid missing the smaller 2N-8N MK. The number of 2N-8N MK declined immediately following irradiation, whereas the number of 16N-64N MK remained normal for 4 days before decreasing. The number of 2N-8N and 16N-64N MK reached minimum around days 7 and 10, respectively, and thereafter increased to supranormal values at days 14 and 20, respectively. Platelet production, measured by 35S incorporation into platelets, increased during the first 4 days, then decreased to minimum about day 10. A rise to supranormal values was present at day 20. All values were about normal 30 days after exposure. The observed pattern may be explained as follows: Most of the 16N-64N MK survive the applied dose and maintain their ability to produce platelets. Some of the 2N-4N and 8N MK survive irradiation and transform into platelet-producing MK. No influx of cells from the MK stem cell compartment into the MK compartment can be observed before day 7 after irradiation. One explanation for this time lag may be that thrombocytopenia, which does not occur before then, is an essential stimulus for MK stem cell activation.

Animals↗
PubMed1984

The effect of splenectomy on platelet formation and megakaryocyte DNA content in rats.

The DNA content of rat bone marrow megakaryocytes (MK) was studied by Feulgen photometry following splenectomy and sham operation, respectively. The DNA measurements were preceded by acetylcholinesterase staining for identification of the 2N-8N MK. The number of 2N-8N MK decreased to minimum values, while the number of 16N-64N MK increased to maximum values about 4 days following both splenectomy and sham operation. However, the changes were somewhat more pronounced following splenectomy than sham operation. The total MK number did not change significantly. Platelet production, measured by 35S incorporation into platelets, increased during the first 2 days and remained high for 6-7 days, increasing the platelet counts. All values were about normal 30 days after surgery, except for a minor thrombocytosis following splenectomy. The early, highly significant thrombocytosis, following both splenectomy and general surgery, is caused by increased production of platelets due to the surgical trauma. This is caused by a direct action on bone marrow MK by transforming 2N-8N MK into higher ploidy classes. Lack of splenic platelet pooling may influence the grade and duration of the early thrombocytosis after splenectomy. The late, long-lasting, minor thrombocytosis, which occurs after splenectomy but not after sham operation, can be explained by the removal of the splenic platelet pool.

Animals↗
PubMed1983

Mycosis fungoides in Norway 1960-80. A retrospective study.

The paper presents the results of a cooperative, retrospective study of mycosis fungoides in Norway, in 112 patients diagnosed histologically between 1960-80. The study includes an analysis of incidence, clinicopathological findings, survival, mortality and autopsy findings. In addition, other factors, such as occupation, the incidence of cancer, associated illnesses and contact allergies are reviewed. The significant prognostic variables with regard to survival included, age at diagnosis, stage of the disease at diagnosis and occupation. Industrial workers showed the highest incidence of MF and the poorest prognosis in terms of survival after biopsy. In 59% of deceased MF patients, the cause of death was related to MF.

Adult↗
PubMed1983

Low ploidy megakaryocytes in steady-state rat bone marrow.

The amount of DNA in individual megakaryocytes (MK) was measured by Feulgen photometry performed on smears of steady-state rat bone marrow. The MK were identified by acetylcholinesterase (ACHE) staining. The method described is particularly suitable in the study of immature MK, hitherto difficult to examine for DNA content. The main MK ploidies were 8N, 16N, and 32N, comprising 33.4% +/- 1.4%, 40.8% +/- 1.4%, and 17.9% +/- 1.3%, respectively, of the total MK numbers. Only 6.7% +/- 1.7% had less than octoploid DNA content. Very few cells were found belonging to the 64N class. Among the immature MK, a relatively large fraction was found between the ploidy levels, indicating a rapid turnover within these ploidy classes. The demonstration of ACHE activity even in MK with a diploid DNA content indicates that the flow from the committed progenitors to differentiated MK occurs at the 2N level.

Animals↗
PubMedDate not supplied

Endoluminal radiotherapy for rectal tumors.

The present study was performed to evaluate local tumor control and side effects of endoluminal radiotherapy given to patients with rectal tumors. Twelve patients with adenocarcinoma and 10 patients with villous/adenovillous adenomas were treated with curative intent from 1989 to 1995. The majority of patients were of advanced age and in poor medical condition, and had previously been found unable to undergo radical surgery or colostomy. Three patients had tumor remains following radiotherapy, they successfully received local surgery (n = 2) or an iridium implant (n = 1) as second-line treatment. Two patients (adenomas) later experienced a local relapse. No serious side effects were observed. We conclude that endoluminal radiotherapy is an efficacious option for patients with malignant or premalignant tumors in the lower rectum who are in poor medical condition.

Adenocarcinoma↗
PubMedDate not supplied

Prognostic factors in anal carcinoma.

This study was performed to examine if commonly recorded parameters are of prognostic importance for patients with squamous cell carcinoma of the anal canal. A total of 77 patients received combined chemoradiotherapy and were followed at regular intervals after treatment. Age, sex, performance status, tumour stage, histopathological differentiation and grade, were not found to be of prognostic importance. Most blood tests did not correlate with prognosis, although elevated serum alkaline phosphatase (ALP) and lactate dehydrogenase (LD) proved to be unfavourable prognostic factors. In the present study serum ALP and LD were the only parameters that significantly correlated with development of distant metastases during follow-up.

Adult↗
PubMedDate not supplied

Anal carcinoma: a clinical approach to p53 and RB gene proteins.

The role of p53, retinoblastoma (RB) and c-erbB-2 gene proteins in the pathogenesis of anal carcinomas has been examined. A total of 97 patients were included in the study. c-erbB-2, RB and p53 proteins were abnormal in 0, 5 and 34% of the cases, respectively. No correlation was observed between p53 and age, sex, tumour stage, histopathological tumour grading, human papilloma virus (HPV) affection or prognosis. It is concluded that the c-erbB-2 gene is not involved in the development of anal carcinomas; the role of the RB gene is somewhat uncertain, while p53 may be involved in about 1/3 of the cases. However, p53 is not correlated with HPV infection or clinical or histopathological data.

Adult↗