Effects of cupric chloride and tamrabhasma, a traditional Indian preparation of copper, on eicosanoid production by human gastric and colonic mucosa

Tamrabhasma is a traditional copper oxide-containing Indian preparation which has anti-ulcer activity. We have studied the effect of tamrabhasma and CuCl2.2H2O on prostaglandin formation by human gastric and colonic mucosa and submucosa, as prostaglandins have mucosal protective activity, and their release may contribute to the anti-ulcer effect. With the gastric mucosa, tamrabhasma 10 micrograms mL-1, but not 0.1 or 1 microgram mL-1, increased prostaglandin E (PGE) concentration by 38% (P < 0.05), with little or no effect on 6-keto-PGF1 alpha, thromboxane B2 or the leukotriene (LT) LTC4/LTD4. CuCl2.2H2O (10 micrograms mL-1) increased 6-keto-PGF1 alpha by 46% (P < 0.05), but 0.1, 1, 50 and 250 micrograms mL-1 did not significantly affect any of the prostanoids, and only the highest concentration reduced the amount of LTC4/LTD4. In the colon mucosa, tamrabhasma (0.1-10 micrograms mL-1) or CuCl2.2H2O (10-50 micrograms mL-1) increased all the prostanoids and this effect was greater than in the gastric mucosa but there was no significant change in LTC4/LTD4. CuCl2.2H2O showed a bell-shaped concentration-effect curve, with no significant effect at lower and higher amounts. Indomethacin (0.1-10 micrograms mL-1) caused a concentration-dependent reduction in the prostanoid amounts. The effect of tamrabhasma was probably not only due to the presence of Cu2+, as tamrabhasma was more effective than CuCl2.2H2O alone; in addition the solubility of CuO is very low. Increased prostanoid levels might explain, at least partly, the gastric mucosal protection by tamrabhasma. The results in the colon, however, raise the possibility that tamrabhasma should be examined for the treatment of inflammatory bowel disease.

A pharmacokinetic study of sulphasalazine and two new formulations of mesalazine

We have examined the pharmacokinetics of enteric coated sulphasalazine compared with two new formulations of mesalazine. These consisted of microgranules of mesalazine coated with Eudragit S in a concentration of either 20 or 25% dry lacquer substance; these in turn were enclosed in capsules coated with Eudragit L. In-vitro dissolution studies of coated microgranules showed that drug release was pH dependent. Studies in 7 normal volunteers showed median peak concentrations of 5-amino-salicylic acid and N-acetyl-5-amino-salicylic acid occurred at about 6 hours with both microgranular preparations, compared with sulphasalazine at 15 h. The microgranule formulation coated with 20% Eudragit S gave serum levels and overall systemic absorption similar to values with sulphasalazine. This new formulation may be of value for delivering mesalazine and other therapeutic agents to the colon.

Changes in tissue fatty acid composition in murine malignancy and following anticancer therapy

We studied the mouse NC tumour, a subcutaneously transplanted adenocarcinoma originally of mammary origin. Measurements per g tissue were made of 17 fatty acids (FAs), the combined amounts of n-3, n-6, saturated, unsaturated, and total FAs, and of various FA ratios in the tumour, mammary tissue, spleen, liver and plasma. Compared with mammary tissue from normal mice, tumours of vehicle-treated controls had less of seven of the FAs and more of two FAs. Mice bearing the NC tumour often had changed (usually decreased) amounts of FAs in the 'normal' spleen, liver and plasma, but not in mammary tissue. Treatment with methotrexate (MTX) was studied alone and with indomethacin which can potentiate MTX cytotoxicity. Indomethacin 1.25 mg kg-1 (INDO) increased the amounts of 3/17 tumours FAs and the unsaturated FAs, but reduced 9/17 FAs, the saturated and the unsaturated FAs in 'normal' mammary tissue, and usually had no effect on the FAs of other tissues. MTX 2 or 4 mg kg-1 (MTX 2 or 4 mg) +/- INDO in general partly restored (increased) the amounts of tumour FAs, and reduced the saturated/unsaturated FA ratio. In the 'normal' spleen and plasma also, but not in the liver, MTX 2 mg generally somewhat restored the FA composition. However, as in the liver, the spleen 20:4 and 22:6 (which form prostaglandins and lipid peroxides) did not increase in the presence of INDO. With MTX 4 mg, some of the plasma and liver FAs decreased, in contrast to the tumour. There was generally no evidence of MTX potentiation by INDO. These results are discussed in relation to carcinogenesis, cachexia, and the response to treatment.

Methotrexate alters the fatty acid composition of NC adenocarcinoma cells in culture

The effects of methotrexate and indomethacin alone and in combination have been examined on the fatty acid (FA) composition of total cellular lipids in cultured NC adenocarcinoma cells. These studies show that methotrexate can alter the lipid content of cancer cells. Methotrexate 16 ng/ml incubated with NC cells for 2 days increased the content of various FAs. When used alone, indomethacin 1 microgram/ml or methotrexate 8 ng/ml had no significant effect, but in combination caused FA increases, usually to about the same extent as with the higher concentration of methotrexate alone. No FA changes were seen up to 3 h with these drug concentrations or with methotrexate up to 10 micrograms/ml alone or with INDO 1 microgram/ml. These effects may explain previous findings that indomethacin potentiates methotrexate, an interaction which may be important in cancer therapy.

Loading-related increases in prostaglandin production in cores of adult canine cancellous bone in vitro: a role for prostacyclin in adaptive bone remodeling?

Cyclic mechanical loading sufficient to engender strains of physiologic magnitude applied to recently excised canine cancellous bone cores in vitro increased the release of prostaglandin E (PGE) and prostacyclin (PGI2, measured as its breakdown product 6-keto-PGF1 alpha), during a 15 minute loading period in which PG levels were measured in perfusing medium at 5 minute intervals. Peak production occurred in the 0-5 minute sample. Mean levels preload compared to during load were PGE, 2.66 and 3.67 ng/ml (p less than 0.002); and 6-keto-PGF1 alpha, 543 and 868 pg/ml (p less than 0.007). The elevated levels then declined to preload levels during the loading period. However, the 5-10 minute but not the 10-15 minute samples still contained levels greater than preload values. A second 15 minute period of load, 1 h following the end of the first, produced smaller increases in the levels of release that were statistically significant only for the first 0-5 minute sample during load (preload compared to load mean values, PGE, 1.09-1.66 ng/ml, p less than 0.02; 6-keto-PGF1 alpha, 401-558 pg/ml, p less than 0.04). Immunolocalization revealed PGE and 6-keto-PGF1 alpha in lining cells and 6-keto-PGF1 alpha but not PGE in osteocytes. Addition to the medium of 1 microM PGE2, approximating the concentration produced by loading, had no significant effect on the specific activity of the extractable RNA fraction labeled with [3H]uridine, whereas 1 microM PGI2 produced an increase similar to that seen previously with loading.(ABSTRACT TRUNCATED AT 250 WORDS)

Self-reported long-term outcomes of hysterectomy

OBJECTIVES

To investigate women's perceptions of and satisfaction with the long-term outcomes from a hysterectomy performed between 2 and 10 years ago and to determine whether satisfaction is related to demographic factors, factors associated with the hysterectomy, and the number or type of perceived benefits and problems associated with the hysterectomy.

DESIGN

Retrospective survey by telephone interview and postal questionnaire of 236 women who had a hysterectomy between 2 and 10 years ago.

SETTING

Women who had had a hysterectomy were identified from a community survey in the Hunter Region of NSW, Australia.

SUBJECTS

Two hundred and thirty-six women who self-reported having had a hysterectomy between 2 and 10 years ago.

MAIN OUTCOME MEASURES

Perceived benefits resulting from the hysterectomy; perceived physical and psychological problems caused by the hysterectomy; satisfaction with care.

RESULTS

Relief from heavy bleeding was the most frequent benefit (57%) and the most important benefit (32%). Most of the women reported improvements in symptoms experienced before hysterectomy but more than half the women had symptoms which they believed had been worsened or caused by the hysterectomy. Despite this, high levels of satisfaction with the operation were reported.

CONCLUSION

The results highlight the need to examine more closely decision-making about treatment for menstrual symptoms such as heavy bleeding.

Mesalazine release from coated tablets: effect of dietary fibre

Delayed-release mesalazine formulations relay on pH-dependent coat dissolution to ensure delivery of 5-aminosalicylic acid (5-ASA) to the colon. As dietary fibre acidifies the colonic lumen we have studied the effect of fibre supplementation in 10 patients with quiescent colitis. Greater intake of dietary fibre was associated with a decrease in stool pH and an increase in stool frequency and faecal mass. However, the 24 h faecal and urinary excretion of 5-ASA and N-acetyl-5-ASA was unchanged. The percentage of total faecal ASA excreted as N-acetyl-5-ASA correlated with whole-gut transit time, suggesting that prolonged transit may be disadvantageous to patients with colitis as N-acetyl-5-ASA appears to be inactive.

The effect of nifedipine alone or combined with cytotoxic chemotherapy on the mouse NC carcinoma in-vitro and in-vivo

Effects of the calcium antagonist nifedipine on the response of the murine NC carcinoma has been examined alone and together with cytotoxic chemotherapy in-vitro and in-vivo. The cytotoxic drug combination of methotrexate and melphalan, or nifedipine alone (0.2-25 micrograms mL-1), caused a concentration-related reduction of NC cell growth in culture. At the lower concentrations, combination to the cytotoxic drugs with nifedipine resulted in an addition of the separate drug effects, but with drug concentrations that on their own approached maximal effectiveness the combined response was less than additive. NC tumours were excised from mice 14 days after inoculation s.c. with NC cells, weighed, and extracted for prostanoids. Mouse survival was determined up to day 121, and cancer spread was recorded postmortem. Nifedipine 1, 5 or 10 mg kg-1 had little or no effect on the tumour weight, tumour prostanoid content, metastasis to the lymph nodes or lungs, or on the increase of mouse longevity by the cytotoxic drugs.

Studies of three non-peptide cholecystokinin antagonists (devazepide, lorglumide and loxiglumide) in human isolated alimentary muscle and guinea-pig ileum

1. Three recently described non-peptide cholecystokinin (CCK) antagonists (devazepide, lorglumide, loxiglumide) have been studied for their antagonism of the contraction to cholecystokinin-octapeptide (CCK-OP) in human alimentary muscle and guinea-pig intestine. 2. Each antagonist caused a concentration-dependent inhibition of the contraction induced by CCK-OP, regardless of regional and species differences. 3. The potencies of each drug, estimated by use of an adaptation of the Cheng & Prusoff equation, were similar in the different regions of human alimentary tract (weighted mean apparent pKB, +/- s.e. mean: devazepide, 5.76 +/- 0.08, n = 20; lorglumide, 5.82 +/- 0.04, n = 25; loxiglumide, 5.87 +/- 0.07, n = 24). 4. In contrast, the potencies differed markedly in the guinea-pig ileum. Apparent pKB values obtained by the same method as with human tissues were, mean +/- s.e.mean: devazepide, 10.61 +/- 0.61; lorglumide, 7.43 +/- 0.20; loxiglumide, 6.67 +/- 0.12. pKB values obtained from classical competition experiments were: devazepide, 10.09 +/- 0.09; lorglumide 7.70 +/- 0.12; loxiglumide 6.08 +/- 0.22. 5. The CCK receptors in human gut muscle from different regions seem to be similar, but there appear to be species differences.

Polyphloretin phosphate (PPP) antagonists of prostaglandin action also inhibit prostaglandin biosynthesis in-vitro

Several polyphloretin phosphate (PPP) fractions (low mol. wt LC1259; high mol. wt LC1261; crude mixture, LC101) were confirmed in their established property as antagonists of the pharmacological actions of prostaglandins in a preparation of guinea-pig isolated ileum stimulated by prostaglandin (PG)E2. Further samples of the same material were then compared in-vitro with indomethacin in their ability to inhibit prostaglandin biosynthesis from arachidonic acid by a microsomal enzyme preparation. All three PPP fractions potently inhibited prostaglandin generation, with the rank order of potency LC1259 = LC101 = indomethacin greater than LC1261. The oral LD50 in mice was 25 mg kg-1 for indomethacin and greater than 1 g kg-1 for LC101. PPP fractions (especially LC101) may therefore have therapeutic potential as anti-inflammatory agents.

The effects of cholecystokinin octapeptide on human isolated alimentary muscle

1. We studied cholecystokinin octapeptide (CCK-OP) for its motor effects and sites of action on human isolated muscle from stomach, small intestine and colon. 2. CCK-OP induced a concentration-dependent contraction of all the longitudinal muscles and of circular muscle from the stomach and large intestine. The peptide acted directly on these muscles at a site not involving muscarinic receptors. 3. CCK-OP relaxed the circular muscle of the small intestine and/or reduced the contractions to acetylcholine, by stimulating intramural postganglionic inhibitory neurones.

Smoking, eicosanoids and ulcerative colitis

In this study, which is the first of its kind using normal tissue samples that are very difficult to obtain, we have investigated the hypothesis that smoking protects against ulcerative colitis by altering the colonic mucosal formation of prostaglandins and related substances. Colonic mucosa biopsied from healthy young men produced prostaglandin E, 6-keto-PGF1 alpha (formed from PGI2), leukotriene B4 and leukotriene C4/D4/E4 as determined by radioimmunoassay. With each substance, the median yield was lower in the group of smokers who smoked 3 cigarettes in the 2 h before biopsy, than in the non-smokers. However, with each eicosanoid the statistical probability approached only the 10% level, but the fact that the trend was the same for all eicosanoids somewhat strengthens the possibility of a real difference between the groups.

Effect of ethanol on eicosanoid synthesis by human gastric and colonic mucosal pieces

1. Human gastric and colonic mucosa obtained at operation was cut into small pieces and incubated with different concentrations of ethanol. 2. Ethanol (5-40%) caused a concentration-dependent increase in the amounts of prostaglandin E (PGE), thromboxane B2 (TXB2), 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) and (up to 20% ethanol) leukotriene C4/D4 (LTC4/D4) in incubates of mucosal pieces from either region. 3. Higher concentrations of ethanol usually caused small increases or reductions of eicosanoid levels; gastric mucosal PGE and 6-keto-PGF1 alpha were still increased by 100% ethanol, whereas TXB2 was unaltered, and LTC4/D4 was reduced. With the colonic mucosa, 100% ethanol increased PGE but reduced the other eicosanoids. 4. Gastric mucosal pieces incubated in water or phosphate buffer yielded generally similar amounts of eicosanoids. However, colonic mucosa yielded more when incubated in water, possibly indicating a greater sensitivity to osmotic damage. This difference between the two regions is consistent with the ability of the gastric mucosa to resist damage by water on its epithelial surface.

Parathyroid hormone, but not prostaglandin E2, changes the shape of osteoblasts maintained on bone in vitro

Parietal bones from 2-week-old rats were dissected free from the sutural regions, dura mater, and periosteum, leaving the surface covered with osteoblasts and some osteoclasts. Prostaglandin (PG) production by these "stripped" bones under basal conditions and after exposure to parathyroid hormone (PTH) was measured by radioimmunoassay of the culture medium (minimum essential medium with or without added 10% heat-inactivated fetal calf serum). Cultured specimens were examined by scanning electron microscopy for changes in osteoblast length, orientation, ruffling, and overlap. As demonstrated previously, PTH caused the osteoblasts to elongate, align, and show fewer ruffles compared to controls. PTH increased PG synthesis by the stripped bones. Indomethacin inhibited PG formation but did not affect the osteoblast shape change. PGE2, indomethacin, or both drugs together had no discernible effect on any morphologic features. These findings indicate that PGE2 does not change osteoblast shape and that the cell shape change with PTH is not mediated by endogenous prostanoids.

Stimulation of gastric and colonic mucosal eicosanoid synthesis by plantain banana

Extracts of plantain banana (Musa sapientum Linn var. paradisiaca) were studied on the accumulation of eicosanoids in incubates of human gastric and colonic mucosa. The ethanolic extract caused a concentration-dependent increase in the eicosanoid accumulation but the water extract was ineffective. Since all the eicosanoids studied tended to increase, banana may act by increasing the availability of arachidonate. In control tissues the accumulation of PGE and TXB2 in the incubates decreased with time while that of 6-keto-PGF1 alpha increased (colon only, studied).

Effects of gastrointestinal hormones on the growth of human intestinal epithelial cells in vitro

The growth of cultured epithelium like cells from human normal embryonic intestine was studied in response to various hormones using a method that quantifies the number of cells by the amount of dye that they bind after fixation. Gastrin and neurotensin in the pg/ml range and higher caused small increases in cell growth. Glucagon and VIP were stimulatory in the low ng/ml range, whereas somatostatin and bombesin had no effect at the lower concentrations but were stimulatory at the highest concentration tested (10 and 100 ng/ml respectively). Secretin and pancreozymin (cholecystokinin) seemed to be ineffective.

The effects of dipyridamole and indomethacin on methotrexate cytotoxicity in LoVo human colon cancer cells

Dipyridamole and indomethacin were studied for their effects in the in-vitro response of LoVo colon cancer cells to methotrexate (MTX) using a dye elution method. Dipyridamole 0.5-5 micrograms mL-1 or indomethacin 1 microgram mL-1 alone had little or no effect on cell growth. The tumour cells were refractory to even high concentrations of MTX (2.5-10 micrograms mL-1) alone or with indomethacin 1 microgram mL-1. In contrast, dipyridamole 0.5-5 micrograms mL-1 sensitized the cells to MTX 5 micrograms mL-1 (their growth was reduced by 25 to 69%), possibly by inhibiting thymidine salvage.

Breast cancer, prostaglandins and patient survival

Prostaglandins may have both undesirable and desirable effects in malignant disease. Their possible roles in breast cancer were studied by examining the relationships between different variables and the amounts of prostaglandin-like material (PG-LM) extracted from 141 breast carcinomas. Univariate analysis indicates a direct correlation with patient age and menopausal status, with a greater yield from cancers of post- compared with pre-menopausal women. Tumours up to 2 cm diameter yielded more PG-LM than those measuring greater than 2-5 cm. Although there was also a direct correlation with bone metastasis near to the time of surgery, this was because no positive bone scans occurred in patients whose tumours yielded little total PG-LM (less than 16 ng PGE2 equivalents per g tissue). Since tumour PG-LM did not predict later spread to bone, and yields of greater than 16 ng g-1 were similar in the positive and negative bone scan groups, tumour PG-LM appears to be unimportant for skeletal metastasis. There was no obvious relationship of tumour PG-LM to the grade of malignancy, tumour type, amounts of fibrous tissue (and therefore malignant cells), invasion of blood vessels and lymphatics or presence of plasma cells. Multivariate analysis indicates that disease-free survival is longest with an intermediate production of tumour total PG-LM. Of the 82 patients now dead, the cause was attributed to metastatic disease in 69 cases. No relationship of PG-LM to the length of survival was seen with univariate or multivariate analysis. However, when just the post-menopausal patients who died within the first 3 postoperative years were analysed, there was a highly significant inverse correlation between the tumour total PG-LM and the time to death. The reason(s) for these different findings on overall survival compared with just the patients who died are not understood, but the results may indicate that one or more other variables must co-exist with a high tumour PG-LM to hasten death.