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E G De Vries

Publications and source records attributed to E G De Vries.

At least 19 recordsLinked to original sources
PubMed2001

Tamoxifen treatment and gynecologic side effects: a review.

OBJECTIVE: To review the literature on tamoxifen side effects on the female genital tract and psychosexual function in premenopausal and postmenopausal women. DATA SOURCES: We used the English-language literature in MEDLINE and reference lists from selected articles. Search terms included: "tamoxifen and estrogen receptor," "transcription activation," "premenopause," "postmenopause," "vaginal epithelium," "uterus," "endometrial hyperplasia," "polyps," "endometrial cancer," "sonography," "sonohysterography," "hysteroscopy," "myometrium," "myoma," "sarcoma," "endometriosis," "ovarian cysts," "hot flushes," "concentration problems," "sleep disturbance," "vaginal dryness," "sexual function," "libido," "dyspareunia," and "quality of life." No study-type restrictions were imposed. METHODS OF STUDY SELECTION: With respect to clinical studies we included case cohort studies, observational studies; if no trials were available on a subject, case reports published in peer-reviewed journals were selected. For the discussion on endometrial surveillance of tamoxifen users, letters and editorials published in peer-reviewed journals also were used. Subjects of interest were mechanism of action of tamoxifen, tamoxifen and the vaginal epithelium, endometrium, mesenchymal tumors of the uterus, ovaries, sexual function, and vasomotor instability. TABULATION, INTEGRATION, AND RESULTS: Eligible studies were analyzed to determine their usefulness in this review. Data from trials that evaluated tamoxifen side effects on specific genital tissues were combined, with special interest in differentiation of side effects in premenopausal and postmenopausal women. Weighted estimates of severity and extent of side effects were usually not possible because of lack of randomized trials. Only the risk of endometrial cancer in relation to tamoxifen treatment could be estimated. CONCLUSION: The gynecologic side effects of tamoxifen are diverse and reflect the complexity of its mechanism of action, with agonistic and antagonistic effects on various tissues, depending on the ambient estradiol concentration and hence menopausal status of the patient. The most frequently reported side effect was hot flushes, and the most worrisome gynecologic side effect was a two- to three-fold increased risk of endometrial cancer in postmenopausal women. Despite its side effects, the benefits of tamoxifen in controlling breast cancer or prevention of its relapse are still without debate.

Breast Neoplasms↗
PubMed2000

Role of metallothionein in cisplatin sensitivity of germ-cell tumours.

Cisplatin (CDDP) is an extremely active drug in the treatment of germ-cell tumours. Earlier, we found an unexpected inverse correlation between the total amount of sulfhydryl groups and CDDP sensitivity in a panel of 3 human germ-cell-tumour and 3 colon-carcinoma cell lines. Major components of the sulfhydryl groups are glutathione and metallothionein (MT). We further investigated a possible role of MT in the CDDP sensitivity of germ-cell tumours. MT levels and functionality of the germ-cell-tumour and colon-carcinoma cell lines were found to be inversely correlated with CDDP sensitivity. No difference in sub-cellular localization of MT could be observed among the types of cell lines. In agreement with the in vitro data, immunohistochemical detection of MT was high in 11/14 primary human germ-cell tumours and low in 7/7 human colon carcinomas. MT-protein expression in primary germ-cell tumours did not discriminate between responding and non-responding patients. As compared with the primary tumours, MT-protein expression decreased in 5/7 post-chemotherapy residual vital tumours or remained undetectable (2/7). MT-protein expression in the germ-cell tumours was not related to total p53-protein expression. In summary, over-expression of MT was found in germ-cell tumours, both in cell lines and in human tumours. Although MT-protein over-expression seems to be associated with the CDDP sensitivity of germ-cell tumours, MT-protein expression in primary germ-cell tumours did not differ between responding and non-responding patients and therefore cannot be used to predict response to chemotherapy.

Antineoplastic Agents↗
PubMed1999

Carcinoid tumors.

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Carcinoid Tumor↗
PubMed1999

Heat-shock-protein-27 (hsp27) expression in ovarian carcinoma: relation in response to chemotherapy and prognosis.

Heat-shock protein 27 (hsp27) is one of the small heat-shock proteins. Its expression in ovarian- and breast-cancer cell lines has been associated with resistance to cisplatin and doxorubicin. In addition, hsp27 expression appears to facilitate cellular growth, differentiation and motility. In several human carcinomas, hsp27 expression might also be related to worse prognosis. The aim of this study was to evaluate the prognostic value of hsp27 expression in patients with ovarian carcinoma in relation to their response to chemotherapy and overall survival. Hsp27 expression was assessed by immunohistochemistry in 77 patients with ovarian carcinoma stage IC-IV. All patients received cisplatin- and doxorubicin-based chemotherapy and had long-term follow-up. In 30 patients, paired tumour samples were available, obtained before and after chemotherapy. Hsp27 immunostaining was positive in 86% of patients before and in 72% of patients after chemotherapy. Hsp27 expression was not related to any clinicopathologic factor, including previously determined p53 expression. Univariate analysis showed that, in stage-III and -IV patients, younger age, no residual tumour after first laparotomy, < or = 1 litre ascites, response to first-line chemotherapy and absence of hsp27 expression were associated with longer median progression-free survival. However, in multivariate analysis, only age, ascites and response to chemotherapy retained independent prognostic value.

Adult↗
PubMed1999

Differential regulation of IL-6 promoter activity in a human ovarian-tumor cell line transfected with various p53 mutants: involvement of AP-1.

In human ovarian carcinomas, the p53 tumor-suppressor gene is frequently mutated. Interleukin-6 (IL-6) in these tumors is known to stimulate tumor-cell proliferation. In order to evaluate the effect of several p53 phenotypes on the IL-6 promoter activity, the human ovarian wild-type (wt)-p53 cell line A2780 was stably transfected with an empty plasmid (CMV) or (m)-175-, m-248- or m-273-p53. Electrophoretic mobility-shift assays revealed differences in activator protein-1 (AP-1) DNA-binding activity in the various clones. The CMV and m-273 clone had comparable amounts of AP-1. The m-175 clone displayed the least and m-248 the most pronounced AP-1 binding. Supershift analysis of AP-1/DNA complexes with antibodies against the AP-1 sub-units, c-Fos, FosB, Fra-1, Fra-2, c-Jun, JunB, and JunD, revealed that the AP-1/DNA complexes in the various clones had different compositions. Fra proteins were basically present only in m-175 and m-248 AP-1. IL-6-promoter activity was evaluated in the presence and absence of the AP-1 binding site which showed that the m-175-transfected clone has a transcriptional suppressing AP-1, whereas the CMV and the m-273 clones have an activating AP-1. Exposure of the p53 clones to tumor-necrosis factor-alpha (TNF-alpha) clearly altered the AP-1/DNA complex composition. IL-6-promoter activity was enhanced by TNF-alpha irrespective of the presence of an AP-1 binding site, while the degree of activation differed in the various clones, being most pronounced in the m-175 and m-248 clones. The results demonstrate that the basic and activated IL-6-promoter activity is differently regulated in the various p53 clones, possibly due to alterations in the AP-1 composition.

DNA, Complementary↗
PubMed1999

Discrepancy between ultrasonography and hysteroscopy and histology of endometrium in postmenopausal breast cancer patients using tamoxifen.

BACKGROUND: The increased risk of endometrial carcinoma following the use of tamoxifen has stimulated studies on endometrial diagnostic screening methods. In tamoxifen users the endometrial thickening observed with transvaginal ultrasonography (TVU) frequently cannot be confirmed by hysteroscopy or histology. OBJECTIVE: The aim was to investigate the relationship between TVU and hysteroscopic and histologic endometrial findings in postmenopausal patients using tamoxifen. METHODS: Fifty-three asymptomatic postmenopausal tamoxifen-using breast cancer patients underwent a gynecological examination combined with TVU. Patients with an endometrial thickness of >5 mm were offered hysteroscopy and endometrial biopsy. FINDINGS: Thirty-one patients (58%) had an endometrial thickness of >5 mm with enhanced, inhomogeneous echogenicity. Hysteroscopy was performed in 22 patients and 3 underwent hysterectomy. Seven of 22 patients had endometrial polyps, histologically characterized by cystically dilated glands lined with atrophic epithelium and periglandular stromal condensation. Histology of the three hysterectomy specimens showed a similar picture of atrophic luminal epithelium, covering dilated glands lined with atrophic epithelium and surrounded by dense stroma, which resembled the histology of the endometrial polyps. In all three specimens the histologically measured endometrial thickness corresponded with that on TVU. INTERPRETATION: Tamoxifen can induce specific endometrial changes consisting of cystically dilated glands with periglandular stromal condensation while the overlying epithelium remains atrophic. The changes occur either in the endometrium itself or as a protrusion of the endometrium, i.e., as endometrial polyps. These findings explain the discrepancy between ultrasound, hysteroscopy, and histology. Due to the high number of false-positive findings, TVU is not an effective screening instrument in these patients.

Adult↗
PubMed1998

Transport of glutathione conjugates into secretory vesicles is mediated by the multidrug-resistance protein 1.

Intracellular glutathione-conjugate transport was evaluated in the human small cell lung carcinoma cell line GLC4 with low multidrug resistance protein (MRP1) expression and its 300x doxorubicin-resistant, MRP1-over-expressing, GLC4-Adr subline. Transport of non-toxic concentrations of monochlorobimane and 5-chloro-methyl fluorescein diacetate was evaluated using fluorescence microscopy. After exposure to these compounds, fluorescence was observed especially in intracellular vesicles in GLC4-Adr. Immunotransmission electron microscopy showed that MRP1 was present in the vesicle membranes and plasma membrane, while inside the vesicles the glutathione conjugate of 1-chloro-2,4-dinitrobenzene could be detected. Experiments with brefeldin A, which induces arrest in vesicle release from the Golgi complex, indicated that these vesicles may originate from the trans-Golgi network. In GLC4-Adr cells, doxorubicin also was transported in vesicles, with an arrest in vesicle release from the Golgi complex. Our results indicate that MRP1 functions as a glutathione-conjugate transporter not only at the plasma membrane but also in intracellular secretory vesicles.

ATP-Binding Cassette Transporters↗
PubMed1998

Clinical relevance of transforming growth factor alpha, epidermal growth factor receptor, p53, and Ki67 in colorectal liver metastases and corresponding primary tumors.

To determine whether the expression of transforming growth factor alpha (TGF-alpha), its receptor (epidermal growth factor receptor [EGFr]), p53 nuclear protein, and proliferation influences prognosis of patients with liver metastases, a study was performed in 45 liver metastases and 33 corresponding primary colorectal carcinomas in patients referred for liver surgery. The expression of TGF-alpha, EGFr, p53 nuclear protein, and proliferation rate was correlated with clinicopathological characteristics and survival after partial liver resection. In liver metastases, TGF-alpha expression was low in 42%, intermediate in 35%, and high in 23%. TGF-alpha expression was higher in liver metastases derived from lymph node-positive primary carcinomas, in synchronous and in irresectable liver metastases compared with those derived from lymph node-negative primary carcinomas, metachronous, and resectable liver metastases. Nuclear p53 expression was found in 83% of primary tumors and 71% of liver metastases. p53 expression did not correlate with the various clinicopathological characteristics. Ki67 expression was not associated with clinicopathological characteristics in primary and metastatic tumors. In the 38 patients in whom a partial liver resection was performed, median survival was 25 months in patients with a higher TGF-alpha expression in the metastasis than in the primary tumor and 60 months in patients with comparable or lower TGF-alpha expression in the metastasis than in the primary tumor (P = .036). Median survival after liver resection was 21 months in patients with p53-negative liver metastases and 58 months in patients with p53-positive metastases (P = .043). By multivariate analysis, p53 and EGFr expression on liver metastases were the best predictors of disease-free survival after partial liver resection, with relative risks of 2.38 and 3.33, respectively. In patients with colorectal liver metastases, referred for liver surgery, a higher TGF-alpha expression is associated with unfavorable tumor characteristics, whereas p53 and absence of EGFr expression is associated with a better survival after partial liver resection.

Adenocarcinoma↗
PubMed1997

Effects of an inducible anti-sense c-myc gene transfer in a drug-resistant human small-cell-lung-carcinoma cell line.

Small-cell-lung-cancer (SCLC) is characterized by rapid development of resistance to cytotoxic agents, such as cisplatin (cDDP) and anthracyclines. c-myc over-expression is one of the reported genetic alterations in this tumor. Amplification of the c-myc gene in this and other cancers is often correlated with poor prognosis. We studied the existence of a correlation between resistance and activation of the c-myc oncogene in a cDDP-resistant SCLC sub-line, GLC4cDDP, containing a c-myc gene amplification. This cell line was stably transfected with either an anti-sense c-myc (AS) or control (C) expression vector resulting in the sub-clones GLC4cDDP/AS and GLC4cDDP/C respectively. PCR and RT-PCR analysis illustrated the integration and activation of the dexamethasone(dex)-inducible MMTV-LTR promoter linked to the complete AS-c-myc fragment in GLC4cDDP/AS cells, but not in GLC4cDDP/C cells. Dex-induced AS-c-myc RNA resulted in 50% growth inhibition during the first 48 hr, which declined to 25% at 72 hr. In addition, AS-c-myc RNA expression reduced the cloning efficacy by 36% and induced 2-fold more apoptosis within 24 hr in GLC4cDDP/AS cells. Dex treatment did not affect the proliferation, clonogenicity and induction of apoptosis in the control cell lines. Furthermore, AS-c-myc RNA expression caused a 1.4-fold increased cDDP sensitivity but no change in doxorubicin or vincristine sensitivity in GLC4cDDP/AS cells. Our results indicate that AS-c-myc RNA expression causes inhibition of cell proliferation, induces apoptosis, reduces clonogenicity and interferes with cDDP sensitivity but not with doxorubicin or vincristine sensitivity.

Carcinoma, Small Cell↗
PubMed1997

Mechanism of hyperthermic potentiation of cisplatin action in cisplatin-sensitive and -resistant tumour cells.

In this study, the mechanism(s) by which heat increases cis-diamminedichloroplatinum (cisplatin, cDDP) sensitivity in cDDP-sensitive and -resistant cell lines of murine as well as human origin were investigated. Heating cells at 43 degrees C during cDDP exposure was found to increase drug accumulation significantly in the cDDP-resistant cell lines but had little effect on drug accumulation in the cDDP-sensitive cell lines. DNA adduct formation, however, was significantly increased in all cell lines studied. Furthermore, ongoing formation of platinum (Pt)-DNA adducts after the end of cDDP treatment was enhanced and/or adduct removal was decreased in heated cells, resulting in relatively more DNA damage remaining at 24 h after the end of cDDP exposure. Correlation plots with survival revealed weak correlations with cellular Pt accumulation (r2 = 0.59) and initial Pt-DNA adduct formation (r2 = 0.64). Strong correlations, however, were found with Pt-DNA adducts at 6 h (r2 = 0.97) and 24 h (r2 = 0.89) after the incubation with the drug. In conclusion, the mechanism by which heat sensitizes cells for cDDP action seems to be the sum of multiple factors, which comprise heat effects on accumulation, adduct formation and adduct processing. This mechanism did not seem to differ between cDDP-sensitive and -resistant cells, emphasizing the potential of hyperthermia to reduce cDDP resistance.

Animals↗
PubMed1996

Potential use of recombinant human interleukin-6 in clinical oncology.

Recombinant human IL-6 (rhIL-6) is a pleiotropic cytokine with stimulatory actions on the hematopoietic system, the immune system and hepatocytes. Clinical interest in the use of this cytokine was raised because of its thrombopoietic properties and also because of its anti-tumor activity, which was shown in vitro and in the preclinical setting. Various studies show that doses up to 10 mu kg/kg/d rhIL-6 before and after chemotherapy are tolerable and the most frequent side-effects encountered consist of flu-like symptoms. Furthermore, a consistent decrease in hemoglobin was reported during rhIL-6 treatment. This was probably due to hemodilution, although a change in ferrokinetics, may also at least partly, explain the anemia. An evident increase of platelets has been observed in various studies. After chemotherapy, rh-IL6 seemed to hasten platelet recovery, without affecting platelet nadir. Preliminary data from studies investigating the value of rhIL-6 as an anti-tumor agent in renal cell carcinoma and melanoma reported low response rates, between 8 and 14%. The results of rhIL-6 in ameliorating chemotherapy induced bone-marrow depression and especially thrombocytopenia, are promising and merit further phase III studies.

Acute-Phase Reaction↗
PubMed1995

Sensitization to cisplatin action by step-down heating in cDDP-sensitive and -resistant cells.

Hyperthermia treatment (> or = 43 degrees C) has been shown to be able to (partially) reverse acquired cDDP resistance. However, such heat treatment is difficult to achieve in the clinic. Short pre-treatment at a high temperature (> 42 degrees C), immediately before a treatment at a lower temperature (< 42 degrees C) can enhance the heat toxicity of the lower temperatures. This "step-down heating schedule" was explored for its possible drug-sensitizing potential in in vitro-cultured cDDP-sensitive and -resistant murine and human tumour cells. A 10-min pre-treatment at 44 degrees C enhanced the cytotoxicity of 41 degrees C hyperthermia alone. It also enhanced sensitivity to cDDP when given at 37 degrees C. However, it did not increase the 41 degrees C-induced cDDP sensitization. Thus, no correlation was found between heat kill and cDDP sensitization for step-down heating schedules. The observed effects of step-down heating were comparable in sensitive and in resistant cells, so the step-down heating schedule, unlike the 43 degrees C treatment, did not lead to a decrease of the cDDP-resistance factor. Yet the total cytotoxicity caused by this treatment protocol was 10-fold more than for cDDP with 41 degrees C alone, due to the extra hyperthermic cell killing and the cDDP-sensitizing effect of the pre-treatment. This treatment could have a substantial impact on cDDP efficacy in the clinic even when cDDP resistance has developed.

Animals↗
PubMed1995

Carboplatin- and cisplatin-induced potentiation of moderate-dose radiation cytotoxicity in human lung cancer cell lines.

The interaction between moderate-dose radiation and cisplatin or carboplatin was studied in a cisplatin-sensitive (GLC4) and -resistant (GLC4-CDDP) human small-cell lung cancer cell line. Cellular toxicity was analysed under oxic conditions with the microculture tetrazolium assay. For the platinum and radiation toxicity with the clinically relevant dose ranges applied, this assay was used to obtain information on cell survival after the treatments. Apart from effects on cell survival effects on DNA were also investigated. Configurational DNA changes could be induced by platinum drugs and thereby these drugs might change the frequency of DNA double-strand breaks (dsbs). DNA fragmentation assayed with the clamped homogeneous electric field (CHEF) technique was used as a measure for dsbs in DNA. The radiosensitising effect of the platinum drugs was expressed as enhancement ratio (ER) calculated directly from survival levels of the initial slope of the curve. The highest ER for cisplatin in GLC4 was 1.39 and in GLC4-CDDP 1.38. These were all at 75% cell survival. Carboplatin showed increased enhancement with prolonged incubation up to 1.21 in GLC4 and was equally effective as cisplatin in GLC4-CDDP. According to isobologram analysis, prolonged incubation with both platinum drugs showed at least additivity with radiation for both cell lines at clinically achievable doses. GLC4-CDDP showed cross-resistance to radiation. The radiosensitising capacity of both lung cancer cell lines was not dependent on their platinum sensitivity. The formation of dsbs in DNA directly after radiation was not influenced by pretreatment of either drug in the sensitive or in the resistant cell line. Drug treatment resulted in decreased DNA extractability in control as well as in irradiated cells. Modest enhancement ratio for radiosensitisation by platinum drugs cannot be explained on the level of dsb formation in DNA in both cell lines. Interaction of radiation with the clinically less toxic carboplatin can be improved by prolonged low-dose carboplatin exposure before irradiation and is as potent as cisplatin in the resistant lung cancer cell line. This suggests an advantage in combining radiation and carboplatin in lung cancer patients.

Antineoplastic Agents↗
PubMed1993

Mechanism of the protective effect of supplemental dietary calcium on cytolytic activity of fecal water.

Dietary calcium supplementation inhibits hyperproliferation of rectal epithelium, possibly by precipitating luminal surfactants and thus preventing their cell-damaging effects. Therefore, we studied the effects of supplemental dietary calcium (35.5 mmol/day) on composition and cytolytic activity of fecal water and on the release of the epithelial marker alkaline phosphatase in 12 healthy volunteers. Fecal water was isolated by low-speed centrifugation. Cytolytic activity was determined as lysis of human erythrocytes by fecal water. Intestinal alkaline phosphatase activity in fecal water was measured with the use of the uncompetitive inhibitor L-phenylalanine. Supplemental calcium increased soluble calcium and decreased soluble P(i). The logarithm of the concentration product of calcium and phosphate was linearly dependent on pH. These observations indicate formation of insoluble calcium phosphate. Supplemental calcium did not alter the total bile acid concentration in fecal water but significantly decreased the ratio of more hydrophobic to more hydrophilic bile acids from 3.3 to 2.3. Calcium also significantly decreased the concentration of fatty acids (from 2.9 to 2.1 mM). Consistent with these decreases in hydrophobic surfactants, calcium decreased the cytolytic activity of fecal water from 47 +/- 9 to 27 +/- 8% (n = 12, P < 0.05). Analogous to the decrease in cytolytic activity, the release of the epithelial marker alkaline phosphatase was also lowered by supplemental calcium. We conclude that supplemental dietary calcium decreases luminal cytotoxic surfactant concentrations and thus inhibits luminal cytolytic activity and the release of the epithelial marker alkaline phosphatase as an indicator of intestinal epitheliolysis. This mechanism may explain how dietary calcium could decrease epithelial cell proliferation.

Adult↗
PubMed1993

Recent developments in diagnosis and treatment of metastatic carcinoid tumours.

In carcinoid patients a tumour of enterochromaffin cell origin is present, which dependent on the site of origin can result in increased serotonin production. Metastasized carcinoids are often diagnosed by measuring 5-hydroxyindoleacetic acid excretion in the urine. This excretion, however, can be influenced by food intake. On the other hand, serotonin measured in blood platelets is unaffected by food intake and, in addition, is found to be more sensitive. Therapy of metastasized carcinoids is directed at tumour reduction or only reduction of symptoms. Tumour reduction can be achieved surgically or by embolization. Combination chemotherapy has a maximum response percentage of about 33%. Over the last few years, both octreotide and interferon alpha have been used in these patients. They rarely result in a reduction of the tumour size (10-20%). Symptom reduction is achievable in most patients with these agents, however. Recently, increasing knowledge obtained concerning the various serotonin receptors and their antagonists is now being used in the treatment of patients with a metastasized carcinoid. In the future it is expected that the different modalities will be combined increasingly.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

Calcium and the prevention of colon cancer.

Diet is a major determinant of colon cancer risk. Calcium may protect against colon cancer, presumably by binding cytotoxic bile acids and fatty acids. Numerous studies support this proposition. In subjects at risk for colon cancer oral calcium supplementation has been shown to reduce rectal epithelial proliferation rate, thereby supposedly decreasing cancer risk. In contrast to the original hypothesis that phosphate counteracts the effect of calcium, evidence has now been provided that phosphate is crucial for the intraluminal binding of bile acids in complexes of calcium, phosphate, and bile acids. Supplemental calcium has been shown to reduce the cytotoxic potential of fecal water, which is probably attributable to the profound effect of calcium on bile acid and fatty acid metabolism. However, some reservation with regard to the protective ability of calcium seems to be warranted as we found that oral calcium supplementation caused an increase in epithelial proliferation rate in the sigmoid of patients with adenomatous polyps. Further controlled studies evaluating the effects of calcium on the epithelium of different parts of the colon should now be performed.

Animals↗
PubMed1990

Effects of supplemental dietary calcium on the intestinal association of calcium, phosphate, and bile acids.

It has been suggested that supplemental dietary calcium decreases hyperproliferation of colonic epithelial cells because calcium precipitates and thus inactivates luminal bile acids. Therefore, 12 healthy men were studied before and after dietary calcium supplementation (35.5 mmol/day) to quantify intestinal associations of calcium, phosphate, and bile acids. The supplemental dietary calcium was almost completely (95%) recovered, mainly in feces. Calcium increased the fecal excretion of both phosphate (31%) and bile acids (53%) and decreased the ratio of dihydroxy to trihydroxy bile acids in duodenal bile almost twofold. In vitro studies showed that precipitation of glycodeoxycholic acid was caused by the formation of insoluble calcium phosphate. Water-soluble and calcium-associated amounts of phosphate and bile acids in feces were measured by resolubilization studies, using the calcium chelator ethylenediaminetetraacetate. In both the control and calcium periods, significant amounts of phosphate (80% and 90%) and bile acids (33% and 50%) were calcium-associated. Moreover, the calcium-induced increments in fecal phosphate and bile acids were completely calcium-associated. Calcium decreased the amount of water-soluble phosphate but not of bile acids. These results indicate that supplemental calcium stimulates formation of insoluble calcium phosphate in the intestinal lumen and thus increases binding of luminal bile acids.

Bile Acids and Salts↗