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G Griffioen

Publications and source records attributed to G Griffioen.

At least 73 records · Page 4Linked to original sources
PubMed1995

Glutathione S-transferase pi in colorectal tumors is predictive for overall survival.

Glutathione S-transferases (GSTs) are enzymes involved in the detoxification of xenobiotics and are divided into four subclasses, alpha, mu, pi, and theta, with different although overlapping substrate specificities. Most human gastrointestinal tumors contain increased amounts of GST-pi and GST enzyme activity. The relationship between GST parameters and tumor and patient characteristics, including overall survival, were studied retrospectively in 100 primary colorectal adenocarcinomas. Levels of GST-alpha, GST-mu, GST-pi, and GST enzyme activity were not related to the Dukes stage, differentiation grade, localization, histological type and diameter of the tumor, or gender and age of the patient. Fifty-seven patients died (median survival, 21 months; range, 1-65 months) during follow-up, and 43 patients were still alive at the closing date of the study (median follow-up, 68 months; range, 60-87 months). Optimal dichotomization and uni- and multivariate analyses were done with the Cox proportional hazard model. Multivariate analysis with all clinicopathological parameters revealed higher Dukes stage (hazard ratio, 2.7; P < 0.001) and older age (hazard ratio, 2.8; P = 0.001) to be the only independent prognostic variables for overall survival. In contrast to GST-alpha and GST-mu, high levels of GST-pi (hazard ratio, 3.1; P = 0.002) and GST enzyme activity (hazard ratio, 2.0; P = 0.020) in the tumors were found to have a significant prognostic value independent from the clinicopathological parameters when added separately to this Cox model. Thus, this study indicates that GST subclass levels in colorectal adenocarcinomas are not related to clinicopathological parameters and that the GST-pi level and GST enzyme activity have a prognostic value for the overall survival of the patients.

Adenocarcinoma↗
PubMed1995

Transcription activation of yeast ribosomal protein genes requires additional elements apart from binding sites for Abf1p or Rap1p.

All ribosomal protein (rp) gene promoters from Saccharomyces cerevisiae studied so far contain either (usually two) binding sites for the global gene regulator Rap1p or one binding site for another global factor, Abf1p. Previous analysis of the rpS33 and rpL45 gene promoters suggested that apart from the Abf1 binding site, additional cis-acting elements play a part in transcription activation of these genes. We designed a promoter reconstruction system based on the beta-glucuronidase reporter gene to examine the role of the Abf1 binding site and other putative cis-acting elements in promoting transcription. An isolated Abf1 binding site turned out to be a weak activating element. A T-rich sequence derived from the rpS33 proximal promoter was found to be stronger, but full transcription activation was only achieved by a combination of these elements. Both in the natural rpL45 promoter and in the reconstituted promoter, a Rap1 binding site could functionally replace the Abf1 binding site. Characteristic rp gene nutritional control of transcription, evoked by a carbon source upshift or by nitrogen re-feeding to nitrogen starved cells, could only be mediated by the combined Abf1 (or Rap1) binding site and T-rich element and not by the individual elements. These results demonstrate that Abf1p and Rap1p do not activate rp genes in a prototypical fashion, but rather may serve to potentiate transcription activation through the T-rich element.

Base Sequence↗
PubMed1995

Contribution of plasma cortisol to corticosteroid-suppressed peripheral blood natural killer cell activity in Crohn's disease.

We recently showed that patients with active ileocecal Crohn's disease (CD) have a temporarily suppressed peripheral blood natural killer (NK) cell activity during treatment with oral budesonide or prednisolone. This suppression was caused by a decrease in the number of CD16+ NK cells in the circulation. In the present study we evaluated the contribution of cortisol in plasma to this suppressed NK cell activity. The CD patients took part in a controlled study where they received either oral budesonide or prednisolone for 10 weeks. Before treatment, and at 4 and 10 weeks of treatment, peripheral blood NK cell activity, numbers of circulating CD16+ NK cells, and plasma cortisol levels were analysed. These parameters were determined both before and 30 min after administration of adrenocorticotropic hormone (ACTH). The ACTH-induced plasma cortisol increase was accompanied by a stimulated NK cell activity, when both are suppressed by corticosteroid treatment, without changing the number of CD16+ NK cells. Therefore, a low plasma cortisol level contributes to the corticosteroid mediated NK cell suppression in active ileocecal CD.

Administration, Oral↗
PubMed1995

Plasminogen activators and inhibitor type 1 in neoplastic colonic tissue from patients with familial adenomatous polyposis.

The plasminogen activation cascade is involved in carcinogenesis, invasion and metastasis. In this study plasminogen activators and their type 1 inhibitor were evaluated in colonic tissue from 19 patients with familial adenomatous polyposis coli, an inherited disorder characterised by the presence of thousands of adenomatous polyps in the colorectum which predispose to colorectal cancer. The conversion of normal-appearing colonic mucosa to neoplastic tissue in these patients was associated with an increase in urokinase-type plasminogen activator and plasminogen activator inhibitor type 1, accompanied by a decreased level of tissue-type plasminogen activator. These observations are essentially similar to those found in solitary adenomas and carcinomas of the colon, and illustrate the uniform involvement of the plasminogen activation system in colorectal carcinogenesis.

Adenocarcinoma↗
PubMed1995

Budesonide and prednisolone suppress peripheral blood natural killer cells in Crohn's disease.

AIM: To study the effect of oral budesonide and prednisolone on peripheral blood natural killer (NK) cell activity in patients with active ileocaecal Crohn's disease (Crohn's disease activity index, CDAI > or = 200). METHODS: One group of patients was treated for 10 weeks with oral budesonide (n = 9; 9 mg/day), and another group of patients for the same period with prednisolone (n = 9; 40 mg/day). Budesonide was tapered to 6 mg/day after 8 weeks and prednisolone after 2 weeks to 5 mg/day in the last week. Before treatment, and at 2, 4 and 10 weeks of treatment, natural killer cell activity was determined with a 51Cr release assay, and the number of CD16+ NK cells by Fluorescence activated cell sorter (FACS) analysis. RESULTS: Budesonide, as well as prednisolone treatment, significantly decreased natural killer cell activity at weeks 2 and 4. This decrease was found to be accompanied by a similar decrease in the number of CD16+ NK cells. At 10 weeks, natural killer cell activity had almost returned to pre-treatment levels in the budesonide group and was significantly higher than pre-treatment levels in the prednisolone group. Disease activity was significantly decreased in all patients at week 2 until the end of the trial period. CONCLUSION: Both budesonide and prednisolone treatment suppress peripheral blood natural killer cell activity of patients with active ileocaecal Crohn's disease by decreasing the numbers of CD16+ NK cells in the circulation.

Adult↗
PubMed1994

Nutritional upshift response of ribosomal protein gene transcription in Saccharomyces cerevisiae.

Switching Saccharomyces cerevisiae from non-fermentative to fermentative growth by adding glucose to a medium with glycerol as the sole carbon source, leads to a sudden increase in the rate of ribosomal protein gene transcription. By analyzing the nutritional shift response in a variety of yeast mutants and in the presence of different drugs, evidence was obtained that: (i) no de novo protein synthesis is required for this response; (ii) protein kinase A is essential, though independent of intracellular levels of cAMP, whereas protein kinase C is not involved; (iii) proper regulation of sugar phosphorylation is essential; (iv) glycolysis is required for the long term effect of the nutritional upshift; and (v) pathways leading to glucose-induced activation differ from those leading to gene repression, probably already at the level of glucose transport.

Cyclic AMP↗
PubMed1994

Prognostic relevance of plasminogen activators and their inhibitors in colorectal cancer.

Human colorectal carcinogenesis has been shown previously to be associated with impressive changes in the tissue levels of plasminogen activators and their inhibitors, exemplified by an increase in the urokinase-type plasminogen activator (u-PA) and the inhibitors PAI-1 and PAI-2, and a decrease in tissue-type plasminogen activator (t-PA). In the present study we evaluated the prognostic significance of these parameters to the overall survival of patients with colorectal cancer, in conjunction with several major clinicopathological parameters like age, gender, differentiation grade, and Dukes' stage. Univariate analyses revealed that a low t-PA antigen level, low t-PA activity, and high u-PA/t-PA antigen ratio in normal mucosa and a high u-PA and PAI-2 antigen level in carcinomas are prognostic for a poor overall survival of patients with colorectal cancer. The prognostic value of t-PA antigen and activity in normal mucosa, the antigen ratio of u-PA in carcinoma (C) and t-PA in corresponding normal (N) mucosa [u-PA(C)/t-PA(N) antigen ratio], and PAI-2 antigen in carcinomas was found to be independent from clinicopathological parameters by multivariate analyses. These observations illustrate the clinical importance of the plasminogen activation cascade at the tissue level in colorectal cancer invasion, metastasis, and survival.

Aged↗
PubMed1994

Inactive urokinase and increased levels of its inhibitor type 1 in colorectal cancer liver metastasis.

BACKGROUND/AIMS: Human colorectal carcinogenesis was previously found to be associated with an increased urokinase-type plasminogen activator expression, both in antigen and activity, accompanied by simultaneously enhanced levels of plasminogen activator inhibitors type 1 and type 2. This increased proteolytic activity may contribute to invasive growth and metastasis of the tumors. METHODS: In the present study, homogenates of liver metastases, primary colorectal carcinomas, and adjacent normal tissues were evaluated regarding the level and composition of urokinase, tissue-type plasminogen activator, and plasminogen activator inhibitors. RESULTS: Concentrations of urokinase were significantly increased in primary carcinomas and liver metastases compared with normal tissues, whereas tissue-type plasminogen activator levels were significantly decreased. Liver metastases showed, in contrast to the carcinomas, hardly any activity of plasminogen activators, which could be attributed to the enhanced presence of the inactive proenzyme form of urokinase in combination with more complexes of plasminogen activators with inhibitors. Furthermore, liver metastases had an eightfold higher content of inhibitor type 1 compared with the primary carcinomas. The excess of inhibitors was confirmed by addition of plasminogen activators to metastasis homogenates, which resulted in increased complex formation. CONCLUSIONS: Colorectal cancer metastasis in the liver is associated with an inactivation of the enhanced urokinase cascade, which might allow tumor cells to settle in the liver.

Colorectal Neoplasms↗
PubMed1994

Protective effect of blood transfusions on postoperative recurrence of Crohn's disease in parous women.

BACKGROUND: Perioperative blood transfusion (BT) appeared to have adverse effects on survival after surgery for malignant tumors while pretransplantation BT suppressed allograft rejection. Interest grew in the effect of BT on postoperative recurrence of Crohn's disease. STUDY DESIGN AND METHODS: To determine the effect of perioperative BT on the recurrence of Crohn's disease after primary surgery, the medical histories of 148 patients with Crohn's disease, 62 males and 86 females (49 nonparous and 37 parous), were reviewed. Eighty-seven patients received perioperative BT. RESULTS: Overall, perioperative BT showed no effect on recurrence. Patients with Crohn's disease limited to the ileum had a better prognosis with regard to recurrence than did patients with Crohn's disease located in the colon or located in both ileum and colon, but the difference was not significant. Perioperative transfusion seemed to protect against recurrent disease after colon resection, which might be explained by the fact that colon resections, which often necessitate perioperative BT, generally result in a shorter bowel segment at risk for recurrent disease. Overall, parous women showed a worse prognosis than nonparous females and men (p = 0.022). Transfusions had a beneficial effect in parous women (p = 0.068) and, after correction for type of operation, this beneficial effect was significant (p = 0.026). After perioperative BT, parous women had a similar prognosis with respect to recurrent Crohn's disease as nonparous females and men. CONCLUSION: Perioperative BT has a beneficial effect on the postoperative recurrence of Crohn's disease in parous women.

Adolescent↗
PubMed1994

Tetranectin expression in human colonic neoplasia.

The expression of tetranectin in colonic neoplasia was evaluated by determining the tissue distribution by immunohistological analysis of tissue sections and the antigen levels in tissue homogenates and plasma. In normal colonic mucosa tetranectin staining was predominantly found in the goblet cells whereas in adenocarcinomas this staining was confined to the tumour stroma. Colonic adenomas, benign precursors of adenocarcinomas, showed fewer tetranectin positive goblet cells and in some cases showed tetranectin expression in the stroma. Within the tissue homogenates no differences were found in the tetranectin levels between normal mucosa, adenomas and carcinomas. Patients with colonic cancer were found to have significantly decreased plasma tetranectin levels compared to healthy controls. Thus, colonic neoplasia is associated with a change in the tissue distribution of tetranectin, without an obvious change in the tissue level, and a low plasma tetranectin level.

Adenocarcinoma↗
PubMed1994

Clinical heterogeneity of familial colorectal cancer and its influence on screening protocols.

The age at onset of non-polyposis colorectal cancer (CRC) was investigated in 49 families with at least three relatives affected in two successive generations. Forty one of these families satisfy the accepted minimum criteria for hereditary non-polyposis CRC. The remaining eight families were distinguished by a late age of disease onset and, hence, could not be included in the group. The condition in these latter families has been designated provisionally, as late onset familial CRC. The hereditary non-polyposis CRC families include 194 patients, 110 men and 84 women (mean age at diagnosis: 44 years; range: 16-74 years). Ninety two per cent of the patients were diagnosed by age 60. Colorectal cancer was diagnosed at progressively earlier ages in successive generations (p < 0.0005). The late onset CRC families comprised 30 patients, 20 men and 10 women (mean age at diagnosis: 62 years; range: 51-77 years). Fifty eight per cent of the CRCs in the patients belonging to the hereditary non-polyposis CRC families were located in the right colon compared with 13% in the late onset familial CRC group (p < 0.001). Multiple CRCs were found in 23% of the cases in the former but in only 3% in the latter families (p < 0.05). Adenomas associated with CRC were reported in 14.5% of the cases in the hereditary non-polyposis CRC families and in 30% of the cases in the late onset familial CRC group (p = NS). Extracolonic cancers, frequently encountered in hereditary non-polyposis CRC, were not found in the late onset CRC families. These findings indicate that there is a distinct clinical entity of non-polyposis CRC in which colorectal cancer develops at a more advanced age than in hereditary non-polyposis CRC. Future molecular genetic studies should confirm this hypothesis. In the meantime, recognition of these late onset familial CRC families, which will rest on clinical observations, is important because of the implications for the screening protocol.

Adolescent↗
PubMed1994

Activity of Crohn disease assessed by measurement of superior mesenteric artery flow with Doppler US.

PURPOSE: To test the hypothesis that increased blood flow in the superior mesenteric artery (SMA) reflects disease activity in patients with Crohn disease. MATERIALS AND METHODS: Duplex Doppler sonographic measurements of SMA blood flow volume were obtained in 10 patients with active Crohn disease, 10 patients with chronic inactive Crohn disease, and 10 healthy volunteers. Disease activity was determined with clinical and laboratory indicators. RESULTS: Interstudy reproducibility of repeated SMA flow volume measurements was good (r = .98). A marked increase in SMA flow volume was noted in patients with active disease compared with patients with inactive disease and healthy volunteers: 1,588 mL/min +/- 576 versus 288 mL/min +/- 113 and 417 mL/min +/- 147, respectively (P < .05 for both comparisons). CONCLUSION: Activity of Crohn disease causes a substantial increase in SMA flow volume. Measurement of SMA blood flow may be an important noninvasive, readily available, inexpensive tool that can be used to monitor Crohn disease objectively.

Adolescent↗
PubMed1994

Increased prevalence of colonic adenomas in patients with acromegaly.

Forty-nine acromegalics and 57 controls matched for age and sex underwent colonoscopy. The control group consisted of patients investigated because of atypical abdominal complaints compatible with irritable bowel syndrome or constipation. The exclusion criteria for both groups included: age over 75 years, previous colonic polyps or cancer, previous colonic surgery, rectal blood loss, anemia, previous abdominal radiation, sigmoidoscopy, colonoscopy or barium enema performed for any indication within 3 years prior to the present study. Colonoscopy was successful in reaching the cecum in 72 and 77% of the controls and acromegalics, respectively (p = NS). Eleven (22%) of 49 acromegalics had biopsy-proven colonic adenomas versus only five (9%) of the control group (p < or = 0.05). Multiple adenomas were found in three of the 11 acromegalics and in none of the controls. In five of these 11 patients and in only one of the controls, at least one adenoma was located in the right colon. In addition, acromegalics tended to have larger adenomas. The group of acromegalics with and without adenomas did not differ significantly in age or duration of active disease. In conclusion, the present study shows that acromegalic patients have an increased risk of developing colonic adenomas.

Acromegaly↗
PubMed1993

Non-allelic heterogeneity of familial adenomatous polyposis.

Linkage studies on familial adenomatous polyposis (FAP) reported so far suggest that FAP is a genetically homogeneous disease. Recently, we found that the putative gene for Turcot syndrome, an apparently autosomal recessive clinical variant of FAP, is not allelic to FAP. Here we describe another family, segregating for an autosomal dominant disease clinically indistinguishable from FAP but genetically not linked to the APC locus, adding further evidence for the occurrence of non-allelic heterogeneity of FAP. These observations have implications to the linkage-based genetic counselling of persons at risk for FAP especially when they are drawn from small families giving insufficient information.

Adenomatous Polyposis Coli↗
PubMed1993

[Combination external and internal radiotherapy for esophageal carcinoma: a new prospect].

Thirty-five patients with an inoperable or non-resectable oesophageal carcinoma were treated with external radiotherapy to a maximum dose of 60 Gy followed by a booster irradiation by means of intraluminal brachytherapy at a low dose rate (40-112 cGy/h). For this extra irradiation, which lasted 20-36 h, a catheter with a thickness of 3 mm was introduced through the nose. This treatment could be carried out without sedation. The total radiation dose after the combination therapy amounted to 65-75 Gy. Of the 35 patients, 17 were pretreated with dilatation or laser therapy. The palliative effect after the external and internal irradiation was very good; only one patient still had minor dysphagia 6 weeks after the treatment. Transient irradiation oesophagitis occurred in 16 patients. In three patients, a secondary benign stenosis developed. The median duration of survival was 11 months, the 2-year survival rate was 10%. A comparison of these results with a historical control group treated only with external irradiation shows that the duration of survival of these patients appears to be increased during the first 45 weeks.

Adult↗
PubMed1993

Growth-related expression of ribosomal protein genes in Saccharomyces cerevisiae.

The rate of ribosomal protein gene (rp-gene) transcription in yeast is accurately adjusted to the cellular requirement for ribosomes under various growth conditions. However, the molecular mechanisms underlying this co-ordinated transcriptional control have not yet been elucidated. Transcriptional activation of rp-genes is mediated through two different multifunctional transacting factors, ABF1 and RAP1. In this report, we demonstrate that changes in cellular rp-mRNA levels during varying growth conditions are not parallelled by changes in the in vitro binding capacity of ABF1 or RAP1 for their cognate sequences. In addition, the nutritional upshift response of rp-genes observed after addition of glucose to a culture growing on a non-fermentative carbon source turns out not to be the result of increased expression of the ABF1 and RAP1 genes or of elevated DNA-binding activity of these factors. Therefore, growth rate-dependent transcription regulation of rp-genes is most probably not mediated by changes in the efficiency of binding of ABF1 and RAP1 to the upstream activation sites of these genes, but rather through other alterations in the efficiency of transcription activation. Furthermore, we tested the possibility that cAMP may play a role in elevating rp-gene expression during a nutritional shift-up. We found that the nutritional upshift response occurs normally in several mutants defective in cAMP metabolism.

Base Sequence↗