Oestrogen receptor beta expression and depth of myometrial invasion in human endometrial cancer

We assessed the relative expression of oestrogen receptor (ER)alpha and oestrogen receptor (ER)beta mRNAs in 36 human endometrial cancers using a multiplex polymerase chain reaction (PCR). To determine whether or not the expression of ER subtypes in endometrial cancers is associated with clinicopathological parameters, we examined correlations between ER subtypes and age, tumour grade and depth of myometrial invasion. Using multiple regression analysis, myometrial invasion showed a significant correlation with ER-beta: ER-alpha ratio (r = 0.54, P = 0.0007). The ER-beta:ER-alpha ratio was high in advanced invasive carcinoma. Western blotting analysis showed that ER-beta proteins were highly expressed in comparison with ER-alpha proteins in endometrial cancer with severe myometrial invasion. Our results suggest that ER-beta is important in the progression of myometrial invasion.

Effect of 1,25(OH)2D3 on expression of estrogen receptor-alpha mRNA on rat osteosarcoma cell line (ROS 17/2.8)

In order to investigate the regulatory mechanisms of estrogen receptors (ER) in bone cells, changes in ER-alpha mRNA levels of rat osteosarcoma cell line (ROS 17/2.8) before and after exposure to 1,25(OH)2D3 and 17-beta estradiol respectively were measured by quantitative polymerase chain reaction using an internal standard. ER mRNA levels in the ROS 17/2.8 cultured with the medium alone had 5.029 +/- 1.623 mol/g total RNA x 10(-13) and were not statistically different from those cultured in the presence of 1,25(OH)2D3 at concentrations of 10(-12) M and less. ER mRNA levels in the ROS 17/2.8 cell line showed a small but a significant increase as a result of stimulation by 1,25(OH)2D3 at concentrations of 10(-10) and 10(-11) M. However, ER mRNA levels in ROS 17/2.8 cultured in the presence of 1,25(OH)2D3 at concentrations of 10(-9) M were not statistically different from those of the control. On the other hand, the expression of ER in ROS 17/2.8 cells cultured for 3 hours with various doses of 1,25(OH)2D3 showed, by immunoblotting methods, a significant increase at the dose of 10(-10) M in the expression of ER. Although a physiological significance is obscure, these observations suggest that 1,25(OH)2D3 plays a part in the expression of ER in ROS 17/2.8. No significant changes were seen in the expression of ER mRNA and the synthesis of ER as a result of stimulation by the estradiol.

Changes in bone mineral density after orchidectomy and hormone replacement therapy in individuals with androgen insensitivity syndrome

Changes in bone mineral density (BMD) after orchidectomy and after hormone replacement therapy were reported in two patients with complete androgen insensitivity syndrome (AIS). Diagnosis of AIS was made by clinical features and confirmed by the presence of 46,XY karyotype and the presence of testis component in the removed gonads. BMD at the lumbar spine and at three sites of the femur was measured by dual energy X-ray absorptiometry (DXA). The Z scores of the lumbar spine BMD before orchidectomy were -0.8 and -3.1, confirming that patients with AIS have low BMD and that androgen plays an important role in bone mineralization in 46,XY individuals. Castration reduced BMD, but treatment with daily doses of 1.25 mg of conjugated oestrogen and 10 mg of medroxyprogesterone acetate increased BMD. These results indicate that both oestrogen and androgen play an important role in balancing BMD in men.

The long-term effect of menopause on postmenopausal bone loss in Japanese women: results from a prospective study

The aim of this study was to elucidate perimenopausal bone loss in relation to menstrual conditions and to investigate the long-term effect of menopause on bone loss in aged women. The rate of change in bone mineral density (BMD) was measured twice at an exact interval of 12 months by dual-energy X-ray absorptiometry (DXA) at the lumbar spine in 176 pre- and postmenopausal healthy women 41-65 years of age. Serum follicle-stimulating hormone, intact and N-fragment osteocalcin (OC), three types of vitamin D3, parathyroid hormone (PTH), and calcitonin were also determined. Women who exercised regularly or had anatomical changes at the lumbar spine were excluded from this study. The subjects were divided into eight groups based on their menstrual status and years since menopause. Annual bone loss at the lumbar spine of premenopausal women with regular menstruation was -0.2+/-1.9% (95% confidence interval, -0.9 approximately -0.4%) and was not statistically different from zero, while that of women with irregular menstruation or at menopausal transition was -2.1+/-3.4% (-3.4 approximately -0.8%), and -3.3+/-2.3% (-5.2 approximately -0.3%), respectively, and was significantly different from zero. Serum OC levels of women at menopausal transition were significantly higher than those of women with regular menstruation, suggesting that bone loss had commenced in these women. The rate of annual change in BMD of women who were menopausal for 1-3, 4-6, 10-12, and more than 13 years was -3.1+/-4.0% (-4.7 approximately -1.5%), -1.2+/-2.6% (-2.2 approximately -0.2%), -1.0+/-3.0% (-2.3 approximately -0.3%), and -2.3+/-2.1% (-3.7 approximately -1.0%), respectively, and was significantly less than zero. But the annual bone loss of women who were menopausal for 7-9 years was -1.5+/-2.6% (-3.0 approximately -0.1%) and was not statistically significant from zero. These results indicate that postmenopausal women lose BMD in two phases. The early bone loss is rapid and commences during irregular menstruation, then is attenuated within 6 years after the onset of menopause. The second bone loss commences after the attenuation of the first bone loss. Among bone metabolic hormones, intact PTH alone showed an age-related increase and was suggested as being a causal factor of bone loss in women who were menopausal for 13 years or more.

Estrogen receptor gene polymorphism and bone mineral density at the lumbar spine of pre- and postmenopausal women

In order to analyze the role of the estrogen receptor (ER) gene allelic polymorphisms on bone mineral density (BMD), 173 pre- and postmenopausal women were divided into four groups according to their menstrual status (group A: premenopausal women; group B: late premenopausal women; group C: postmenopausal women who had menopause for 5 years or less; and group D: postmenopausal women who had menopause for more than 5 years), and the relationship between ER gene polymorphism and lumbar spine BMD, the percent annual change in BMD and biochemical markers were studied. The restriction fragment length polymorphism (RFLPs) were represented as Xx (XbaI) and Pp (PvuII), with upper case and lower case letters signifying the absence or presence of restriction sites, respectively. In group A, the Xx genotype had significantly higher BMD (p < 0.01) than the xx genotype, but the difference was lost in groups B, C, and D. Because the percent annual change in BMD of group A was 0.052% and was not statistically different among genotypes, it is suggested that RFLP by Xba I is closely linked with peak bone mass that was attained during the subject's late thirties. In group B, serum N-region osteocalcin (N-OC) levels and the percent annual change in BMD showed a significantly larger increase than that of group A, indicating postmenopausal bone loss had commenced. Because the N-OC level of the Xx genotype was significantly higher than that of the xx genotype (p < 0.05), and the percent annual change in BMD of the Xx genotype showed a tendency to increase (p = 0.072), it is suggested that the high BMD of the Xx genotype is rapidly lost during menopausal transition. There were no significant relationships between RFLP and BMD in groups C and D, and between RFLP and BMD in groups C and D, and between RFLP by PvuII and BMD. The present study suggests that the Xx genotype is involved in accretion of BMD during young adulthood, but the effect was lost during menstrual transition.

Prevention of postmenopausal bone loss with minimal uterine bleeding using low dose continuous estrogen/progestin therapy: a 2-year prospective study

OBJECTIVE

To re-examine the minimal effective dose of conjugated estrogen (CEE)-progestin hormone replacement on postmenopausal bone loss.

DESIGN

A 2-year, prospective, open label, randomized study.

SETTING

Department of Obstetrics and Gynecology of a university hospital.

PARTICIPANTS

Fifty-two postmenopausal or oophorectomized women.

INTERVENTION

One of the following regimens was continuously administered for 2 years: (1) CEE 0.625 mg/day, (2) CEE 0.625 mg + medroxyprogesterone (MPA) 2.5 mg/day, (3) CEE 0.31 mg + MPA 2.5 mg/day and (4) control.

MEASUREMENTS

Lumbar spine and femoral BMD by dual energy X-ray absorptiometry (DXA), a monthly based incidence of bleeding, serum lipids, PTH, calcitonin. A1-p, and osteocalcin.

RESULTS

Of the 52 patients enrolled in this study, 49 patients completed the 1 year of therapy and 36 completed the 2- year study. The control group showed a significant decrease in lumbar BMD over the 2 years (P < 0.05). The % changes in lumbar BMD at 2 years of CEE alone, CEE 0.625 + MPA and CEE 0.31 + MPA were 8.52% (95% confidence intervals; 4.61 approximately 12.4%), 7.4% (0.60 approximately 14.2%) and 3.20% (0.61 approximately 5.84%), respectively, and were significantly higher than pretreatment values. The incidence of bleeding was significantly lower in women taking CEE 0.31 mg + MPA. HDL cholesterol increased in women taking CEE 0.625 mg alone or with MPA. No significant changes in lipid profiles were seen in the control or in the group of women taking CEE 0.31 mg + MPA.

CONCLUSIONS

Continuous hormone replacement therapy (HRT) using 0.31 mg of CEE and 2.5 mg of MPA is effective in increasing lumbar BMD in postmenopausal or oophorectomized women and can be an appropriate option for women with a normal lipid profile or those women wishing to eliminate unscheduled bleeding.

Quantification of estrogen receptor messenger RNA by quantitative polymerase chain reaction using internal standard fragment

A simple and reliable polymerase chain reaction-based method for quantifying human and rat estrogen receptor (ER)-mRNA is described. This method involves co-amplification of cDNA transcribed from sample RNA with an internal standard to reduce tube to tube amplification variations. Human and rat internal standards were synthesized by insertion of a DNA fragment near the midportion of human and rat target ER cDNA molecules. After co-amplification, both products of target ER cDNA and internal standard were separated on agarose gel by electrophoresis and transferred onto a membrane filter. The radioactivity hybridized with 32P-labeled ER cDNA was counted. The ER mRNA content was calculated by linear regression analysis after obtaining a logarithm of ratios between the sample and the internal standard radioactivity. The coefficient of variation of this assay was 18.8%. An absolute amount of ER mRNA in less than 10(4) cultured cells could be measured.

Calcium supplements increase bone mineral density in women with low serum calcium levels during long-term estrogen therapy

In order to clarify whether the long-term effect of estrogen on bone mineral density (BMD) is reinforced by low dose calcium supplements, 600-800 mg of calcium lactate was administered to postmenopausal or oophorectomized women who had been undergoing unopposed estrogen therapy for at least 2 years and whose serum calcium level was suppressed to below the normal range. To patients whose serum calcium levels had been within the normal range, the same dose of estrogen alone was continued. Changes in lumbar spine BMD before and after calcium supplementation was measured by dual-energy X-ray absorptiometry. Lumbar spine BMD decreased by -0.37% for 2 years in women treated with estrogen alone, while that of women treated with estrogen and calcium increased by 2.78% (P = 0.003). These results indicate that low dose calcium supplements potentiate the effect of estrogen in women with decreased serum calcium during long-term hormone replacement therapy.

Intestinal absorption mechanism of amphoteric beta-lactam antibiotics II: Michaelis-Menten kinetics of cyclacillin absorption and its pharmacokinetic analysis in rats

The absorption of cyclacillin at pH 7.0 by the rat small intestine was investigated using in situ perfusion. At the lowest dose of 95 microgram/ml, the antibiotic disappearance was rapid and followed first-order kinetics, with the disappearance being 85% at 100 min. At the intermediate concentrations of 770 and 1200 microgram/ml, the disappearance after 100 min was 69 and 54%, respectively, and semilogarithmic plots clearly showed convex curvatures. At the highest concentration of 30 mg/ml, cyclacillin disappeared slowly from the perfusate, in an apparent first-order fashion. The disappearance was 26% after 100 min of perfusion and was similar in extent at 5.2 mg/ml. This concentration-time profile was satisfactorily fitted to the simultaneous Michaelis-Menten and first-order kinetic equations. The area under the blood concentration versus time curve (AUC) after a single intraduodenal dose of cyclacillin was almost consistent with the AUC after the equivalent intravenous dose (10 mg/kg). Additional evidence from a pharmacokinetic analysis of steady-state blood concentrations after constant infusion of cyclacillin through the portal vein and the small intestinal lumen indicated that cyclacillin absorption by the rat intestinal tissue at relatively low concentrations (less than 1 mg/ml) followed solely Michaelis-Menten kinetics. Cyclacillin may be transported by certain types of carrier-mediated mechanisms.

Intestinal absorption mechanism of amphoteric beta-lactam antibiotics I: Comparative absorption and evidence for saturable transport of amino-beta-lactam antibiotics by in situ rat small intestine

The disappearance of various beta-lactam antibiotics from in situ rat small intestinal loops was studied at pH 7.4. For monobasic penicillins, despite the wide variety of apparent partition coefficients in isobutyl alcohol-water, the disappearance from the jejunal loops was almost 30% (+/- 5% SD). On the other hand, the disappearance of amphoteric derivatives of penicillins and cephalosporins having very low lipid solubility varied widely between 12 and 80%. The peak blood levels after intraduodenal administration to the rats correlated well with the extent of disappearance of amphoteric penicillins from the intestinal loops. Absorption studies utilizing in situ intestinal loops were performed at variable dose ranges to yield a clear dose-dependent disappearance. It is suggested that certain carrier-mediated transport systems underlie the absorption mechanism of amphoteric beta-lactam antibiotics.

GI absorption of beta-lactam antibiotics I: kinetic assessment of competing absorption and degradation in GI tract

An equation was derived for the simultaneous assessment of rate constatns for absorption and nonenzymatic degradation of unstable drugs in in situ absorption experiments. The equation was substantiated by using a variety of beta-lactam antibiotics in the recirculation technique through the rat small intestine. Plots of the apparent first-order rate constant for the disappearance of the drug from the gut lumen versus the reciprocal of the volume of recirculating solution yielded a straight line with a slope equal to the intrinsic absorption rate constant and with an intercept equal to the nonenzymatic degradation rate constant in the GI lumen. The kinetic method for evaluation of the absorption rate constant also was developed for a more complex situation in the GI lumen involving absorption, nonenzymatic degradation, and enzymatic metabolism. The proposed method was confirmed with carbenicillin indanyl, which was metabolized rapidly to carbenicillin by the action of nonspecific esterase in the intestine. In the absence of information of Michaelis--Menten kinetic parameters, the present method is advantageous for evaluation of the intrinsic absorption rate of all unstable drugs.

Thermal analysis of the spores of Bacillus cereus with special reference to heat activation

The heat activation of bacterial spores was studied by means of differential thermal analysis in the temperature range 30-110 degrees C using the spores of Bacillus cereus. The thermogram showed three endothermic peaks at 56, 95, and 103 degrees C with one exothermic peak at 105 degrees C during the heating process. The spore coat separated from the native spores also showed a peak at 56 degrees C on its heating thermogram. The peak at 56 degrees C was reversible for both native spores and the spore coat. It was suggested that this peak at 56 degrees C might be related to the heat-activation process that takes place in the spore-coat region. It seems that the peak is due to the denaturation or the structural change of the spore-coat protein that might facilitate either the permeation of germination stimulators or the release of some germination inhibitor into or out of the spores.

Proton conduction in phosphatidylethanolamine

The dc conductivity of polycrystalline phosphatidylethanolamine (PE) was measured in the temperature range 60-120 degrees C. Since no conclusive evidence had so far been obtained for the presence of proteon conduction in this phospholipid, hydrogen gas was shown in the present experiment to evolve during the electrolysis in its premelted state between 91 and 124 degrees C. In this temperature range molecules assume rotation around the molecular axes and proton conduction of the Grotthus type takes place possibly along two chains of intermolecular hydrogen bonds running in parallel. Zwitter-ions behave cooperatively as proton donors and acceptors in transferring proton from molecule and molecule via the hydrogen bond networks. This efficient push-pull way of proton transferring seems to account for the fact that no polarization was observed in the dc conduction experiments. The amount of devolved gas appears to be not exactly in accordance with Faraday's law and discussions are made on possible causes for this slight deviation.