Annotated computed tomography coronary angiogram images and associated data of normal and diseased arteries

Computed Tomography Coronary Angiography (CTCA) is a non-invasive method to evaluate coronary artery anatomy and disease. CTCA is ideal for geometry reconstruction to create virtual models of coronary arteries. To our knowledge there is no public dataset that includes centrelines and segmentation of the full coronary tree. We provide anonymized CTCA images, voxel-wise annotations and associated data in the form of centrelines, calcification scores and meshes of the coronary lumen in 20 normal and 20 diseased cases. Images were obtained along with patient information with informed, written consent as part of the Coronary Atlas. Cases were classified as normal (zero calcium score with no signs of stenosis) or diseased (confirmed coronary artery disease). Manual voxel-wise segmentations by three experts were combined using majority voting to generate the final annotations. Provided data can be used for a variety of research purposes, such as 3D printing patient-specific models, development and validation of segmentation algorithms, education and training of medical personnel and in-silico analyses such as testing of medical devices.

The effect of serifs and stroke contrast on low vision reading

PURPOSE

Patients with low vision are generally recommended to use the same fonts as individuals with normal vision. However, we are yet to fully understand whether stroke width and serifs (small ornamentations at stroke endings) can increase readability. This study's purpose was to characterize the interaction between two factors (end-of-stroke and stroke width) in a well-defined and homogenous group of patients with low vision.

METHODS

Font legibility was assessed by measuring word identification performance of 19 patients with low vision (autosomal dominant optic atrophy [ADOA] with a best-corrected average visual acuity 20/110) and a two-interval, forced-choice task was implemented. Word stimuli were presented with four different fonts designed to isolate the stylistic features of serif and stroke width.

RESULTS

Font-size threshold and sensitivity data revealed that using a single measure (i.e., font-size threshold) is insufficient for detecting significant effects but triangulation is possible when combined with signal detection theory. Specifically, low stroke contrast (smaller variation in stroke width) yielded significantly lower thresholds and higher sensitivity when a font contained serifs (331 points; d' = 1.47) relative to no serifs (345 points; d' = 1.15), E(μ_{sans, low} - μ_{serif, low}) = -14 points, 95 % Cr. I. = [-24, -5], P(δ > 0) = 0.99 and E(μ_{serif, low} - μ_{sans, low}) = 0.32, 95 % Cr. I. = [0.16, 0.49], P(δ > 0) = 0.99.

CONCLUSION

In people with low visual acuity caused by ADOA, the combination of serifs and a uniform stroke width resulted in better text legibility than other combinations of uniform/variable stroke widths and presence/absence of serifs.

Helical Flow in Healthy and Diseased Patient-specific Coronary Bifurcations

Helical flow (HF) exists in healthy and diseased coronary bifurcations and was found to have a protective atherosclerotic vascular effect in other vessels. However, the role of HF in patient-specific human coronary arteries still needs further study, and is therefore the objective of this study in both healthy and diseased bifurcations. Computational studies were conducted on 16 patient-specific coronary bifurcations, including eight healthy and eight identical cases with idealized narrowing to represent disease. In general, higher HF intensity may have a favorable effect as it corelated to the reduction of the percentage vessel area exposed to adverse time averaged wall shear stress (TAWSS%) in both healthy and diseased models. The HF intensity and distribution of each model varies due to the complex shape of patient-specific models. The presence of disease appears to have an important impact on the downstream HF patterns and the TAWSS distributions. Clinical Relevance- By understanding the relationship between HF and hemodynamics, HF may be used as a predictor for the formation and progression of atherosclerotic plaque in coronary arteries instead of near-wall WSS measures, which can be determined with higher accuracy in vivo.

The dispute about sans serif versus serif fonts: An interaction between the variables of serif and stroke contrast

AIM

It is a long-lasting dispute whether serif or sans serif fonts are more legible. However, different fonts vary on numerous visual parameters, not just serifs. We investigated whether a difference in word identification can be attributed to the presence or absence of serifs or to the contrast of the letter stroke.

METHOD

Participants performed a word-recognition two-interval, forced-choice task (Exp. 1) and a classic lexical decision task (Exp. 2). In both experiments the word stimuli were set with four new fonts, which were developed to isolate the stylistic features of serif and letter-stroke contrast. Two measures (i.e., font-size threshold & sensitivity) were analysed.

RESULTS

The threshold measure of both experiments yielded a single significant main effect of stroke contrast such that low stroke contrast elicited lower than high stroke contrast. The sensitivity measure of Experiment 1 yielded a single significant effect of the interaction between serifs and stroke contrast. Specifically, at the sans-serif level, low stroke contrast revealed better sensitivity, relative to high stroke contrast. At the serif level, the opposite stroke contrast pattern was observed.

CONCLUSION

Sans serif fonts with low stroke contrast yield better performance and if a serif font is used, high stroke contrast yields better performance than low stroke contrast. Limitations and future directions are discussed.

Fonts of wider letter shapes improve letter recognition in parafovea and periphery

Most text on modern electronic displays is set in fonts of regular letter width. Little is known about whether this is the optimal font width for letter recognition. We tested three variants of the font family Helvetica Neue (Condensed, Standard, and Extended). We ran two separate experiments at different distances and different retinal locations. In Experiment 1, the stimuli were presented in the parafovea at 2° eccentricity; in Experiment 2, the stimuli were presented in the periphery at 9° eccentricity. In both experiments, we employed a short-exposure single-report trigram paradigm in which a string of three letters was presented left or right off-centre. Participants were instructed to report the middle letter while maintaining fixation on the fixation cross. Wider fonts resulted in better recognition and fewer misreadings for neighbouring letters than narrower fonts, which demonstrated that wider letter shapes improve recognition at glance reading in the peripheral visual view. Practitioner summary: Most of the text is set in fonts of regular letter width. In two single-target trigram letter recognition experiments, we showed that wider letter shapes facilitate better recognition than narrower letter shapes. This indicates that when letter identification is a priority, it is beneficial to choose fonts of wider letter shapes.

Closed letter counters impair recognition

An often-repeated piece of advice when choosing fonts for great legibility is to use fonts with large counters and apertures. To identify effects of open and closed apertures on the letters 'a', 'c', 'e', 'r', 's', 't' and 'f', we ran an experiment using the serif font Pyke as stimulus. The letters in focus were designed for this experiment with three variations of open apertures (Open, Medium and Closed). The experimental paradigm was to present a letter either with or without flankers in the parafovea at 2° eccentricity. The findings showed that participants had more trouble identifying the letter if it was set in a font variation with closed apertures.

The potential impact of an implementation of microalgae-based wastewater treatment on the energy balance of a municipal wastewater treatment plant in Central europe

Integration of a photobioreactor for WWT by microalgae is calculated as a future alternative for cost-efficient and environmentally-friendly nutrient removal for municipal WWTPs. High growth rates and higher biogas yields (compared to conventional sewage sludge) of algal biomass can significantly improve WWTP energy balances. This study focuses on temperate climate zones with changing seasons and discusses energy potential of microalgae-enhanced wastewater treatment for an existing WWTP (32,000 PE) in Central Germany. For WWTP-dimensioning and determination of energy-rich biomasses for anaerobic digestion and CHP, actual influent load data was used and calculation was carried out according to valid regulations. Algae growth figures are based on pilot-scale test series from Germany and correspond to the relevant climatic and local process conditions. Computed results show a shift in the energy balance from a current energy demand of 662,173kWh a^-1 to an energy production of approx. 1,9MWh_el. a^-1 and 1 MWh_th. a^-1.

Biological manganese-dependent sulfide oxidation impacts elemental gradients in redox-stratified systems: indications from the Black Sea water column

The reduction of manganese oxide with sulfide in aquatic redox-stratified systems was previously considered to be mainly chemical, but recent isolation of the Black Sea isolate Candidatus Sulfurimonas marisnigri strain SoZ1 suggests an important role for biological catalyzation. Here we provide evidence from laboratory experiments, field data, and modeling that the latter process has a strong impact on redox zonation in the Black Sea. High relative abundances of Sulfurimonas spp. across the redoxcline in the central western gyre of the Black Sea coincided with the high-level expression of both the sulfide:quinone oxidoreductase gene (sqr, up to 93% expressed by Sulfurimonas spp.) and other sulfur oxidation genes. The cell-specific rate of manganese-coupled sulfide oxidation by Ca. S. marisnigri SoZ1 determined experimentally was combined with the in situ abundance of Sulfurimonas spp. in a one-dimensional numerical model to calculate the vertical sulfide distribution. Abiotic sulfide oxidation was too slow to counterbalance the sulfide flux from euxinic water. We conclude that microbially catalyzed Mn-dependent sulfide oxidation influences the element cycles of Mn, S, C, and N and therefore the prevalence of other functional groups of prokaryotes (e.g., anammox bacteria) in a sulfide-free, anoxic redox zone.

Secondary flow in bifurcations - Important effects of curvature, bifurcation angle and stents

Coronary bifurcations have complex flow patterns including secondary flow zones and helical flow, which directly affect pathophysiological mechanisms such as the development of atherosclerosis. The objective of this study was to generate insights into the effects of curvature, bifurcation angle and the presence of stents on flow patterns and resulting haemodynamics in coronary left main bifurcations. The blood flow and associated metrics were modelled in both idealised and patient-specific bifurcations with varying curvature and bifurcation angles with and without stents, resulting in a total of 128 geometries considered. The results showed that larger curvature of bifurcating vessels has a significant influence on secondary flow, especially with distance to the bifurcation region, causing a skew, spin and asymmetry of Dean vortices, an increase in helical flow intensity with symmetry loss, and a decrease in adversely low time-average wall shear stress (TAWSS). Generally, asymmetric flow patterns coincided with adversely low TAWSS regions. In identical stented geometries, the presence of the stents induced local recirculation immediately adjacent to the stent struts, thus generating adversely low TAWSS in these areas, with some effect on the overall secondary flow. Overall, the effect of stents outweighed the effect of curvature and BA. This new knowledge contributes to a better understanding of the joint effects of curvature, bifurcation angle, and stents on flow patterns and haemodynamics in coronary bifurcations.

The effect of font width on eye movements during reading

Certain font features (e.g., letter width) can change the amount of space occupied by text in published works. Font styles/features are also known to affect reading eye movements (EM); however, few studies have examined these effects - and none used high-resolution displays. We examined the effects of font width on EMs by utilizing four fonts, from the Univers family, which varied in letter-width magnitude. Participants' (n = 25) reading speed, saccade velocity, and the duration/number of fixations and saccades were recorded. The Ultra Condensed font significantly influenced readability and yielded: fewer fixations and saccades; longer fixation durations than the Roman and Extended fonts; and shorter saccade durations, relative to the other fonts. Readers efficiently adjusted their EMs such that no reading-speed differences were observed. The eye-tracking metrics revealed two trade-off effects: (1) fewer and shorter EMs and (2) more and longer EMs, which were revealed by the font-width manipulation.

High letter stroke contrast impairs letter recognition of bold fonts

To make graphical user interfaces look more fashionable, designers often make use of high-stroke-contrast fonts. We are yet to understand how these fonts affect reading. We examined the effect of letter-stroke contrast on three bold fonts, one with extreme contrast between thick and thin strokes, one with no contrast, and one in between. The fonts were designed for this experiment to enable control of font variables. Participants identified the middle letter in a lowercase letter trigram in each trial, briefly presented in the parafovea (at 2° left and right of fixation) and at the foveal fixation point. There was evidence for letter recognition impairment for the font with high stroke contrast compared to the fonts with low and medium stroke contrast, while there was no significant difference in performance between the medium- and low-stroke-contrast fonts. The results suggest that bold fonts with high stroke contrast should not be considered for designs where letter recognition is a priority.

Prognostic values of physical and hematological parameters of dogs naturally infected with parvovirus PVC-2: retrospective study of 103 cases

ABSTRACT Canine parvovirosis is a high mortality disease with acute clinical picture. However, there are few available resources to help stablish prognosis accurately. This study aimed to determine the prognostic threshold values for vital and hematological parameters of dogs naturally infected by the Carnivore protoparvovirus 1 (CPV). A retrospective study of 103 canine parvovirosis cases was carried out. Twenty seven percent of these (28/103) died, 96% (27/28) of which within the first four days of hospitalization. Deceased animals had significantly higher median values for heart (HR) and respiratory (f) rates, as well as significantly lower systolic blood pressure (SBP) than survivors. Severely leukopenic animals (<1,000 cells/μL), had a significantly higher mortality rate (68%, n=13) compared to that of other patients (P<0.0007). Animals with at least two of the following findings: severe hypotension (SBP< 90mmHg), tachycardia (HR > 150 bpm) and leukopenia, represented 34% (34/101) of the cases and had a survival rate of 29% (10/34), while animals with at most one of these parameters represented 66% (67/101) and had a survival rate of 94% (63/67). The presence of two or three abnormal parameters was significantly related to the higher death risk among dogs with parvovirosis (P<0.0001).

Smaller visual angles show greater benefit of letter boldness than larger visual angles

Research has shown that fonts viewed at a smaller visual angle benefit from greater letter boldness. Since small and large visual angles operate on different spatial frequencies, we examined whether the effect was dependent on font size. By applying a paradigm of single-letter exposure across two experiments, we showed that fonts of thinner letter strokes and of extreme boldness decreased recognition for all tested font sizes, and that there was a positive effect of boldness at small visual angles which did not occur at large visual angles. The paper provides evidence that bolder fonts are less effective at improving recognition at larger visual angles, and that over a scale of font weights there is a drop-off at the lightest and the heaviest extremes at all tested font sizes.

A multi-purpose reaction cell for the investigation of reactions under solvothermal conditions

A new versatile and easy-to-use remote-controlled reactor setup aimed at the analysis of chemical reactions under solvothermal conditions has been constructed. The reactor includes a heating system that can precisely control the temperature inside the reaction vessels in a range between ambient temperature and 180 °C. As reaction vessels, two sizes of commercially available borosilicate vessels (V_max = 5 and 11 ml) can be used. The setup furthermore includes the option of stirring and injecting of up to two liquid additives or one solid during the reaction to initiate very fast reactions, quench reactions, or alter chemical parameters. In addition to a detailed description of the general setup and its functionality, three examples of studies conducted using this setup are presented.

MBR technology: a promising approach for the (pre-)treatment of hospital wastewater

Membrane bioreactor (MBR) technology is a very reliable and extensively tested solution for biological wastewater treatment. Nowadays, separate treatment of highly polluted wastewater streams especially from hospitals and other health care facilities is currently under investigation worldwide. In this context, the MBR technology will play a decisive role because an effluent widely cleaned up from solids and nutrients is absolutely mandatory for a subsequent further elimination of organic trace pollutants. Taking hospital wastewater as an example, the aim of this study was to investigate to what extent MBR technology is an adequate 'pre-treatment' solution for further elimination of trace pollutants. Therefore, we investigated - within a 2-year period - the performance of a full-scale hospital wastewater treatment plant (WWTP) equipped with a MBR by referring to conventional chemical and microbiological standard parameters. Furthermore, we measured the energy consumption and tested different operating conditions. According to our findings the MBR treatment of the hospital wastewater was highly efficient in terms of the removal of solids and nutrients. Finally, we did not observe any major adverse effects on the operation and performance of the MBR system which potentially could derive from the composition of the hospital wastewater. In total, the present study proved that MBR technology is a very efficient and reliable treatment approach for the treatment of highly polluted wastewater from hospitals and can be recommended as a suitable pre-treatment solution for further trace pollutant removal.

Full scale membrane bioreactor treatment of hospital wastewater as forerunner for hot-spot wastewater treatment solutions in high density urban areas

Membrane Bioreactors (MBR) are a very attractive option for the treatment of hospital wastewater and elimination of pharmaceuticals in high density urban areas. The present investigation showed that, depending on the substance, between 19% and 94% of the level of antibiotics found in the environment originate from hospitals. Because of their ecotoxic potential, hospital wastewaters can have a significant impact on the environment. The segregation of these wastewaters and their separate treatment at the source can reduce the entry of drugs in waterways and enable water reuse after adequate polishing treatment processes.

Treatment of hospital wastewater effluent by nanofiltration and reverse osmosis

Considerable concern exists regarding the appearance and effects of trace and ultra trace pollutants in the aquatic environment. In this context, it is necessary to identify relevant hot spot wastewater - such as hospital wastewater - and to implement specific wastewater treatment solutions. Membrane bioreactor (MBR) technology seems to be a suitable pre-treatment approach for the subsequent advanced treatment by high pressure membrane systems such as nanofiltration (NF) and reverse osmosis (RO). This paper is based upon investigations on the first full scale MBR for separate treatment of hospital wastewater in Germany. In this study an NF as well as an RO module for further treatment of the MBR filtrate were tested. The removal efficiencies were assessed using the following target compounds: bezafibrate, bisoprolol, carbamazepine, clarithromycin, ciprofloxacin, diclofenac, ibuprofen, metronidazole, moxifloxacin, telmisartan and tramadol. In summary, the results of this study confirmed that MBR technology followed by an advanced treatment for trace pollutant removal is an adequate approach for specific treatment of hot spot wastewater such as hospital wastewater. In particular, it was shown that - comparing the tested NF and RO - only (a two stage) RO is appropriate to remove pharmaceutical residues from hospital wastewater entirely. The recommended yield of the 2-stage RO is 70% which results in a retentate sidestream of 9%. Our investigations proved that RO is a very efficient treatment approach for elimination of trace pollutants.

Evaluation of advanced treatment technologies for the elimination of pharmaceutical compounds

Pharmaceuticals and their metabolites have developed as ecotoxicologically relevant micropollutants in the aquatic environment. During conventional biological wastewater treatment they are eliminated insufficiently and therefore reach surface waters via discharges. They are either partially or completely non-biodegradable and/or hardly eliminable by activated sludge adsorption because they often have polar structures. Membrane bioreactor treatment (MBR) was applied to pre-treat wastewater containing pharmaceutical compounds, e.g., antibiotics like floxacins and their synthetic precursor compounds. Our objectives were to eliminate these persistent target compounds from wastewater prior to discharge into receiving waters. Therefore an advanced treatment applying MBR combined with different chemical and physicochemical processes was performed. The addition of powdered activated carbon (PAC), nano filtration (NF), reverse osmosis (UO) or ozone (O3) and O3/UV were applied to MBR permeate spiked with the selected target compounds. Treatment efficiency was assessed using conventional inorganic and organic chemical analyses besides advanced physicochemical methods like liquid chromatography coupled with mass and tandem mass spectrometry (LC-MS and -MS-MS).

Premenopause contraception with monthly injectable Mesigyna with special emphasis on serum lipid and bone density patterns

This 2-year study compared Mesigyna(R) administered to 49 pre-menopausal women between 38 and 50 years, to 99 women fitted with an IUD (Nova-T). A complete lipoprotein assessment was carried out before treatment and at 6, 12, and 24 months of treatment. A bone densitometry was performed on half of the women, and an endometrial biopsy was taken from half of the Meisgyna group before and at the end of the first and second year. No pregnancy occurred with Mesigyna use while three pregnancies were observed with the IUD. The incidence of bleeding anomalies was higher in the Mesigyna group, with a discontinuation rate for these reasons of 20% versus 4% for IUD (p <0.05). The duration of bleeding days as well as dysmenorrhea were less with Mesigyna. No differences were seen in the pattern of intermenstrual bleeding and spinal bone density between both groups. No patient developed endometrial hyperplasia after treatment, thus endometrial risk seemed not to be increased. Total and LDL cholesterol, and apolipoproteins did not show modifications. A slight decrease in total triglycerides, HDL and HDL(2) cholesterol, and IDL lipoproteins was observed with Mesigyna. The present study appears to be the first using a monthly injectable hormonal contraceptive and monitoring its influence on lipid patterns in premenopausal women. Mesigyna proved to be a highly effective and low risk agent for premenopausal users.

Antihypertensive effect of oral nitrite uptake in the spontaneously hypertensive rat

The lower blood pressure of vegetarians might partly be due to the high dietary load with nitrate which--to a certain extent--is further reduced to nitrite and finally to nitric oxide. To test this hypothesis, spontaneously hypertensive rats received drinking water containing 0, 25, 50 or 100 mmol/l NO2 during 56 days. Food was offered ad libitum or was restricted by 20% (pair-feeding) to simulate the lower energy consumption of vegetarians. Blood pressure, which was monitored at regular intervals, was lowered in a dose-dependent manner by nitrite. This effect was reversible and could not be enhanced by energy restriction. In volunteers plasma nitrate levels increased by a factor of 8 to 32 following the ingestion of a nitrate-rich meal, and mean methemoglobin concentrations increased from 1.2% to 2.4% indicating the endogenous formation of nitrite under these conditions.

Drospirenone: a novel progestogen with antimineralocorticoid and antiandrogenic activity. Pharmacological characterization in animal models

Drospirenone (ZK 30595; 6 beta, 7 beta, 15 beta, 16 beta-dimethylen-3- oxo-17 alpha-pregn-4-ene-21, 17-carbo-lactone) is a novel progestogen under clinical development. Potential applications include oral contraception, hormone replacement therapy and treatment of hormonal disorders. Drospirenone is characterized by a pharmacodynamic profile very closely related to that of progesterone. The progestogenic activity of drospirenone has been analysed in a variety of animal models. The compound efficiently promotes the maintenance of pregnancy in rats, inhibits ovulation in rats and stimulates endometrial transformation in the rabbit. Furthermore, drospirenone shows potent antigonadotropic, i.e. testosterone-lowering, activity in male cynomolgus monkeys. The progestogenic potency of drospirenone was found to be in the range of that of norethisterone acetate or cyproterone acetate. Like progesterone, drospirenone has been shown to have an antimineralocorticoid effect in rats and humans. It has now been demonstrated that the compound has a long-lasting natriuretic activity in rats on administration of a daily dose of 10 mg s.c. for three weeks. Under identical conditions, spironolactone, a widely-used antimineralocorticoid, becomes ineffective after the initial treatment phase. Drospirenone exhibits antiandrogenic activity in castrated, testosterone-substituted male rats as shown by dose-dependent inhibition of accessory sex organ growth (prostate, seminal vesicles). In this model, the potency of drospirenone was found to be about one-third that of cyproterone acetate. The compound is devoid of androgenic, estrogenic, glucocorticoid and antiglucocorticoid activity. Possible drug interaction between drospirenone and ethinylestradiol (EE) was also investigated. EE did not interfere with either the progestogenic or the antimineralocorticoid activity of drospirenone. In conclusion, drospirenone represents a novel type of synthetic progestogen since it combines potent progestogenic characteristics with antimineralocorticoid and antiandrogenic activity. Thus, the pharmacological profile of drospirenone is more closely related to that of the natural hormone progesterone than is that of any other synthetic progestogen in use today. Therefore, drospirenone is anticipated to give rise to a number of additional health benefits both for users of oral contraceptives and hormone replacement therapy recipients.

Effect of the antiprogestin onapristone on follicular growth in women

The effects of the antiprogestin onapristone on the menstrual cycle were assessed in surgically sterilized volunteer women. The steroid was given orally at the dose of 5, 15 or 50 mg/day, from day 5 to day 11 of the cycle. Ovarian ultrasonography and hormonal determinations in plasma and urine were used to monitor the pre-treatment, treated and post-treatment cycles. Onapristone, given at a dose of 5 mg/day, affected follicular growth inconsistently. The dose of 15 or 50 mg/day arrested follicular growth and oestradiol increase and delayed gonadotrophin surge, extending the length of the follicular phase in five of seven women in each group. After discontinuation of treatment the leading follicle resumed its growth and ovulation occurred as judged by the elevation of plasma progesterone, preceded in most but not all cases by an echographic image of follicular collapse. The ensuing luteal phases were not significantly altered in length or plasma progesterone concentration. Cortisol concentrations were unaffected and no serious side-effects were recorded. The antifolliculotrophic effect of onapristone demonstrated here, together with previous reports of similar activity of mifepristone in women, indicate that this may be a general property of compounds that interfere with progesterone receptor function.

Comparative progestational and androgenic activity of norgestimate and levonorgestrel in the rat

The androgenic and the progestational activity of norgestimate (NORG) and levonorgestrel (LNG) were compared in two animal studies. During a Hershberger test in immature castrated male rats and a pregnancy maintenance test in pregnant rats, NORG and LNG were administered subcutaneously at several doses, serum samples were collected from each animal during the treatment period and the concentration of LNG was measured in these samples. It could be shown in both studies that in those animals which were treated with NORG, LNG was a major metabolite present in the serum. The difference in the pharmacological response in LNG- and NORG-treated rats was equivalent to the difference in the exposure of the animals to either directly administered or metabolically derived LNG. This was true for the androgenic and the progestational activity of NORG. It is concluded that according to the present results, NORG can be described as a pro-drug of LNG and that the latter is probably mainly responsible for the pharmacological effects observed during treatment with NORG. It cannot be excluded, however, that NORG itself or other metabolites of this drug may also contribute to the pharmacodynamic response.

Synthesis and biological testing of 4'-(dimethylamino)-17 beta-hydroxy-17 alpha-(1-propynyl)benzo[12,12a]-11 alpha,18-cyclo-12a,12b-dihomo-13 alpha-estr-4-en-3-one: an interesting RU 38 486 analog

A partial synthesis of the title compound, 4'-(dimethylamino)-17 beta-hydroxy-17 alpha-(1-propynyl)benzo[12,12a]-11 alpha,18-cyclo-12a,12b- dihomo-13 alpha-estr-4-en-3-one 1, is reported. The key step in this synthesis represents an intramolecular alkenylaryl radical cyclization. Treatment of 18-[bromo-5-(dimethylamino)phenyl]gona-5,9(11)-diene-3,17-dione-3, 17- bis[cyclic 1,2-ethanediyl acetal] 5 with tributyl tin hydride and a radical initiator introduces the desired 11 beta,18-bridge. The reduced progesterone receptor affinity of this RU 38 486 analog contributes valuable information to the empirical characterization of the steroid binding site of the receptor protein and explains the observed lack of in vivo antigestational activity.

Influence of different progestogens on blood pressure of non-anaesthetized male spontaneously hypertensive rats

The aim of the study was to find out if synthetic progestins with significant antimineralocorticoid activity would have a beneficial effect on blood pressure. Male spontaneously hypertensive rats were treated daily for four weeks with different progestogens by subcutaneous injection. Arterial pressure of the conscious animals was measured at three-day intervals. Progestogens were dosed on the basis of their progestogenic activity, whereby the dosages corresponded to the 10-fold effective dose for inhibition of ovulation in rats. For comparison, spironolactone as well as progesterone itself were included in the study. After four weeks' treatment, plasma volume, extracellular fluid volume (ECFV) and the sodium and potassium concentrations in the plasma were measured. In control animals, there was a slight decrease in blood pressure over the four-week experimental period. Progesterone and spironolactone similarly influenced blood pressure. A new progestin with significant antialdosterone activity, dihydrospirorenone (code No. ZK 30.595), slightly but significantly decreased the ECFV, plasma sodium concentration and slightly but insignificantly decreased blood pressure as compared to vehicle-treated controls. Synthetic progestins lacking this antimineralocorticoid activity did not decrease blood pressure, but rather induced a slight increase in this animal model. The results clearly support the hypothesis that synthetic progestins, like endogenous progesterone, all of them with inherent antialdosterone activity, decrease the ECFV and so might have an impact on extracellular fluid hemostasis as well as blood pressure regulation.

Dihydrospirorenone, a new progestogen with antimineralocorticoid activity: effects on ovulation, electrolyte excretion, and the renin-aldosterone system in normal women

Dihydrospirorenone (DHSP; 6 beta,7 beta,15 beta,16 beta-dimethylen-3-oxo-17- alpha-pregn-4-en-21,17-carbolacton) is an aldosterone antagonist 8 times as potent as spironolactone in the rat. It is also a progestogen that suppresses ovulation in normal women at a daily dosage of 2 mg. The effects of this dosage on the renin-aldosterone system and sodium and potassium balances were investigated in two experiments. In study I, 12 healthy women received a diet with 100 mmol sodium and 60-70 mmol potassium per day from days 3-13 of their normal menstrual cycles. Six women took 2 mg DHSP; 6 others received placebo from days 8-13 of the cycle. Sodium excretion in the DHSP group rose from a mean of 79 to 98.5 +/- 8.3 mmol/day during medication. Placebo had no effect. The difference between average sodium excretion rates in subjects treated with DHSP or placebo was close to significance (P = 0.053). Potassium excretion did not change. Weight loss was slightly greater after DHSP than placebo treatment. PRA and plasma and urinary aldosterone rose significantly during DHSP medication. In study II, 12 women on a free diet were studied during a control and a treatment cyle. From days 5-25 of the second cycle, they took 2 mg DHSP (n = 6) or 1 mg cyproterone acetate. Both compounds suppressed ovulation and the rise in progesterone. During cycle 1, sodium excretion, PRA, and aldosterone were higher in the luteal than in the follicular phase, probably due to an antialdosterone effect of progesterone. DHSP reversed this pattern of natriuresis by inducing a significant early natriuresis and a rise in PRA and aldosterone. Cyproterone acetate only abolished differences in natriuresis between the follicular and luteal phases and the rise of PRA and plasma aldosterone in the luteal phase. We conclude that DHSP may be a suitable partner of ethinyl estradiol as a constituent of an oral contraceptive, since its progestogenic and antialdosterone profile is similar to that of progesterone. Other synthetic progestogens are devoid of an antialdosterone effect. The antialdosterone effect of DHSP may help prevent sodium retention and a rise in blood pressure in susceptible women.

Aldosterone antagonists. 4. Synthesis and activities of steroidal 6,6-ethylene-15,16-methylene 17-spirolactones

Several steroidal 6,6-ethylene-15,16-methylene 17-spirolactones were synthesized to find new progestogens that exhibit both progestational and antimineralocorticoidal activities. The influence of substituents in the 10- and 13-position of the steroidal framework on both properties was investigated. It was found that only compound 12, carrying methyl groups at the 10- and 13-positions, possesses high progestational and antimineralocorticoidal activity.

Lack of binding of gestodene to estrogen receptor in human breast cancer tissue

Competition studies with progesterone and estradiol receptors of human myometrial tissue as well as of mammary cancer tissue showed that gestodene bound with high affinity to the progesterone receptor, as did other synthetic and natural progestogens. However, gestodene did not bind to the estradiol receptor. The relative binding affinities of all tested synthetic and natural ligands showed no organ-specific differences and no differences between neoplastically transformed and normal tissues.

Gestodene: a novel synthetic progestin--characterization of binding to receptor and serum proteins

Gestodene, 17 alpha-ethinyl-13-ethyl-17 beta-hydroxy-4,15-gonadien-3-one, is a new orally active progestational agent, which is available for clinical use in oral contraceptives. The aim of the present study is to make a broad characterization of gestodene at the receptor level and to discuss the results in comparison to those of established progestogens. Kinetic studies of 3H-gestodene uptake show a rapid increase in the amount of specific binding during the first three hours. After saturation, the amount of specifically bound 3H-gestodene remained almost constant up to 24 hours at 4 degrees C. The dissociation of 3H-gestodene from the cytoplasmic myometrial progestone receptor, measured by displacement of labeled steroid with dextran-coated charcoal treatment at 4 degrees C at various times, showed a biphasic or two-component first order dissociation curve. As anticipated, sucrose gradient centrifugation analysis of the 3H-gestodene-labeled cytosol of human myometrial tissue showed that the gestodene binding components sedimented in the 4S and 8S region. A 200-fold molar excess of nonradioactive gestodene reduced only the 8S binding of 3H-gestodene. 4S binding of 3H-gestodene was not reduced, which indicate the existence of a second high capacity binding component. In biological test systems, such as the Clauberg test or Kaufmann test, gestodene has proved to be a very effective progestogen. Among nortestosterone derivatives it is one of the most potent and resembles progesterone biologically in its progestogenic effects. This biologically identical gestagenic activity of gestodene and progesterone is reflected by a very similar behavior in vitro in terms of binding to progesterone receptors of human uterus cytosol. Furthermore, competitive studies indicated that gestodene like other synthetic progestagens also displays some affinity for androgen and glucocorticoid receptors but no measurable affinity for the estrogen receptor. Remarkable is the high binding affinity of gestodene to the binding sites of the mineralocorticoid receptor of rat kidney with a RBA value of 350% compared to aldosterone.

3H-ZK 98,734, a new 11 beta-aryl substituted antigestagen: binding characteristics to receptor and serum proteins

Recently, in the laboratories of Schering in Germany a competitive progesterone antagonist, ZK 98,734, was synthetized, which is characterized by a similar antigestagenic activity as RU 38,486, synthezised by Roussel-Uclaf in France, as assessed by inhibition of nidation tests in rats and guinea pigs. However, this compound has a substantially lower antiglucocorticoid activity measured in cell culture systems than RU 38,486. The purpose of this study was to present a comparison of biochemical and physical properties of the complexes formed by the human uterine progesterone receptor with 3H-ZK 98,734 on one hand and with other well-established progestins on the other hand. ZK 98,734 competed in the same order of magnitude as progesterone or RU 38,486 for the 3H-R5020 binding site of progestin receptor, whereas R5020, Org 2058 or progesterone were unable to compete against 3H-ZK 98,734. This apparent contradiction could be explained by means of FPLC-chromatography and sucrose density centrifugation technique. FPLC-chromatography with an anion exchange column (Mono Q, Pharmacia, Uppsala, Sweden) showed that 3H-ZK 98,734 forms at least two stable complexes with uterine cytosol, on one hand with serum albumin, which presents almost 90% of bound radioactivity, and on the other hand with the two native progestin receptor forms, corresponding to 4S and 8S receptor forms in sucrose density gradient analysis. Competition experiments in liver cytosol of adrenalectomized rats with increasing concentrations of unlabeled ligands other than dexamethasone showed that ZK 98,734, RU 38,486 and cortisol displaced 3H-dexamethasone efficiently from the binding sites in the cytosol. Furthermore, results concerning the specificity of 3H-cortisol binding to serum proteins in diluted pregnant serum demonstrated that ZK 98,734 did not compete with 3H-cortisol for serum binding.

Increased myometrial responsiveness to oxytocin during term and preterm labor

The contractile effects of oxytocin on the longitudinal and circular muscle of rat uteri from animals undergoing term and preterm labor were studied in vitro to define the action of the hormone. The maximal tension and slopes of oxytocin dose contractile-response curves, but not the pD2 values (-log ED50), were higher in both muscle layers at term delivery and also during preterm delivery induced with antiprogesterones compared with responses from tissues of nondelivering animals. These data indicate that the myometrium is hyperresponsive and hyperreactive to oxytocin during term and preterm birth but not hypersensitive. The increase in oxytocin responsiveness of the myometrium may be fundamental to the initiation of labor and regulated by the increases in oxytocin receptors and postreceptor events, including gap junctions.

Endometrial and myometrial effects of progesterone antagonists in pregnant guinea pigs

Three antiprogestogens of the RU 38.486, ZK 98.734, and ZK 98.299, were studied at different stages of pregnancy in the guinea pig. Treatment starting on postconception day 4 completely prevented nidation; all three compounds had comparable inhibitory potency. Treatment after nidation, starting on postconception day 8, induced decidual collapse and bleeding, but embryonic tissue was retained in nidation sites. In contrast to results in animals in nonfertile cycles, luteolysis was not induced, indicating that antiprogestogens lack the ability to induce uterine prostaglandin synthesis/liberation. On postconception day 43, RU 38.486 showed marginal abortifacient activity. The other compounds induced expulsion more rapidly and at a higher rate. The comparatively pronounced antiglucocorticoid activity of RU 38.486 may account for this difference. With RU 38.486, a high level of uterine prostaglandin sensitivity and a cervical ripening were induced consistently and fast; spontaneous labor, on the other hand, occurred after several days, if at all. Complete uterine evacuation was induced within hours by otherwise inactive doses of sulprostone in various combinations with ZK 98.299 RU 38.486 but surprisingly not with ZK 98.734. A single dose of ZK 98.299 induced an approximately thirtyfold increase in uterine prostaglandin sensitivity within 24 hours, exceeding that present before term, but did not induce spontaneous labor. This is evidence that endogenous prostaglandins were not activated, analogous to perinidation stages. Observation of antiluteolytic activity of antiprogestogens in nonpregnant animals is considered of major theoretical importance in this context. It seems that inhibition of progesterone leads to suppressed uterine prostaglandin liberation. The same effect in pregnancy could explain the inability of the uterus to expel a seriously compromised conceptus. In conclusion, we suggest that progesterone is a stimulator rather than a depressor of uterine prostaglandins in the late luteal phase and pregnancy. The ability of the conceptus to neutralize this stimulatory action of progesterone is considered to be essential for the rescue of the corpus luteum and uterine motor quiescence in the guinea pig. The clinical significance of these findings is that the high frequency of incomplete abortions and protracted, sometimes heavy bleeding in pregnant women treated with RU 38.486 may reflect decidual compromise and simultaneous uterine prostaglandin deficiency, as found in our animal model after progesterone blockage.

Studies on the mechanisms of action of progesterone antagonists

Antigestagens of RU-38.486-type were investigated in different pregnancy models reflecting either "endometrial" or "myometrial" effects. All antigestagens were found effective inhibitors of nidation in guinea pigs. This was evidence for a role of embryonic progesterone in the earliest events of nidation. No comparable inhibition could be obtained by ovariectomy. A more complex pharmacology was found around day 43 p.c. when the abortion was brought about by expulsion. RU-38.486 had marginal activity only. Antigestagens with reduced anti-glucocorticoid activity tended to induce abortions more effectively and faster. Some antigestagen-prostaglandin combinations were found of extreme abortifacient activity. Surprisingly it seemed that anti-glucocorticoid properties in addition to (or rather than) antigestagenic activities bring about this synergism with prostaglandin. The employed guinea pig model for pregnancy termination thus characterized two types of antigestagens: ideal ones for monotherapy or combined use with prostaglandin, respectively. Antigestagens induced a highly sensitive myometrium to prostaglandin-stimulation (Sulprostone) and a marked softening and dilatation of the cervix. Antigestagens perfectly prime the genital tract for oxytocic stimuli, they do not overcome the arrested uterine prostaglandin-secretion of the pregnant uterus at the same time.

Synthesis of ent-17-(prop-1-ynyl-17 beta-hydroxy-11 beta-(4-(N,N-dimethylamino)-phenyl)-4,9-estradien-3-one, the antipode of RU-38 486

The title compound was synthesized and tested for its biological activities. It showed neither antiprogesterone nor antiglucocorticoid properties.