Investigations on the in vitro and in vivo metabolic fate of the new synthetic opioid desmethylmoramide using HPLC-HRMS/MS for toxicological screening purposes

New synthetic opioids are an increasing challenge for clinical and forensic toxicologists that developed over the recent years. Desmethylmoramide (DMM), a structural analogue of methadone, is one of the most recent appearances on the drug market. This study investigated its metabolic fate in rat and pooled human liver S9 fraction (pHLS9) to allow the identification of suitable urinary screening targets beyond the parent compound. The analysis of rat urine after the administration of DMM revealed five metabolites, which were the result of pyrrolidine ring or morpholine ring hydroxylation and combinations of them. Additionally, an N',N-bisdesalkyl metabolite was formed. Incubations of DMM using pHLS9 revealed a pyrrolidine hydroxy metabolite, as well as an N-oxide. No Phase II metabolites were detected in either rat urine or incubations using pHLS9. The metabolism of DMM did in part comply with that of its archetype dextromoramide (DXM). Although morpholine ring hydroxylation and N-oxidation were described for DXM and detected for DMM, phenyl ring hydroxylation was not found for DMM but described for DXM. An analysis of 24 h pooled rat urine samples after DMM administration identified the hydroxy and dihydroxy metabolite as the most abundant excretion products, and they may, thus, serve as screening targets, as the parent compound was barely detectable.

Analytical toxicology of the semi-synthetic cannabinoid hexahydrocannabinol studied in human samples, pooled human liver S9 fraction, rat samples and drug products using HPLC-HRMS-MS

Hexahydrocannabinol (HHC) is an emerging semi-synthetic cannabinoid, which is obtained from cyclization of cannabidiol and subsequent hydrogenation. As a potentially legal alternative of ∆9-tetrahydrocannabinol (∆9-THC), it is increasingly seized in the USA and Europe. The aims of this study were to investigate the metabolism of HHC in pooled human liver S9 fraction (pHLS9), rat and human samples. Additionally, a locally obtained low-THC cannabis product was investigated, which was advertised with an elevated concentration of HHC. Overall, HHC formed an 11-hydroxy (HO) metabolite, as well as a carboxy metabolite. While only the parent compound was detected in rat urine and feces, the hydroxy metabolite was additionally detected in pHLS9 and human plasma. The carboxy metabolite was only detectable in human plasma. The metabolism corresponded well to that of ∆9-THC, although glucuronidation and the formation of an 8-HO metabolite were not observed. Detectability of HHC and its carboxy metabolite in rat urine was investigated using gas chromatography-mass spectrometry, but neither the parent compound nor the metabolite were detectable. The investigated low-THC cannabis product appeared to be an actual cannabis product since, in addition to HHC, cannabinol, cannabidiol and ∆9-THC were detected after qualitative analysis. Estimation of its content revealed not only 30.6% of HHC but also 4% of ∆9-THC.

Studies on the In Vitro and In Vivo Metabolic Fate of the New Psychoactive Substance N-Ethyl-N-Propyltryptamine for Analytical Purposes

Prerequisites for the reliable identification of substances in terms of forensic and clinical toxicology or doping control include knowledge about their metabolism and their excretion patterns in urine. N-Ethyl-N-propyltryptamine (N-ethyl-N-[2-(1H-indol-3-yl)ethyl]propan-1-amine, EPT) is an N,N-dialkylated tryptamine derivative, sold as new psychoactive substance, and supposed to act as a partial agonist at the 5-HT2A receptor. The aims of the presented study were to elucidate in vitro metabolites of EPT after incubations with pooled human liver S9 fraction (pS9) and in vivo metabolites excreted into rat urine. Finally, suitable analytical target compounds should be identified. Analysis of pS9 incubations using liquid chromatography-high-resolution tandem mass spectrometry revealed EPT metabolites formed after N-dealkylation as well as alkyl and aryl hydroxylation and formation of a hydroxy sulfate. Investigations using rat urine after oral dosing showed that the metabolic pathways of EPT shifted from in vitro hydroxylation of the alkyl amine group to an increased in vivo hydroxylation of the indole ring with several N-dealkyl metabolites. A glucuronic acid conjugate after hydroxylation of the indole ring was additionally found in vivo. The parent compound could not be detected in the rat urine samples. Therefore, analytical methods using mass spectrometry should include hydroxy-EPT and two hydroxy-EPT glucuronide isomers for reliable identification.

Methadone-mediated sensitization of glioblastoma cells is drug and cell line dependent

PURPOSE

D,L-methadone (MET), an analgesic drug used for pain treatment and opiate addiction, has achieved attention from oncologists and social media as possible chemoensitizing agent in cancer therapy, notably brain cancer (glioblastoma multiforme, GBM). MET has been reported to enhance doxorubicin-induced cytotoxicity in GBM cells via activation of the µ-opioid receptor (MOR). Here, we extended this work and quantified the toxic effect of MET in comparison to other opioids alone and in combination with doxorubicin and the clinically more relevant alkylating drug temozolomide (TMZ), using a set of GBM cell lines and primary GBM cells.

METHODS

MOR expression in GBM cells was investigated by immunofluorescence and immunoblotting. Resistance to drugs alone and in combination with anticancer drugs was assessed by MTT assays. Concentration effect curves were fitted by nonlinear regression analysis and IC50 values were calculated. Apoptosis and necrosis rates were determined by annexin V/propidium iodide (PI)-flow cytometry.

RESULTS

MET alone was cytotoxic in all GBM cell lines and primary GBM cells at high micromolar concentrations (IC50 ~ 60-130 µM), observed both in the metabolic MTT assay and by quantifying apoptosis and necrosis, while morphine and oxycodone were not cytotoxic in this concentration range. Naloxone was not able to block MET-induced cytotoxicity, indicating that cell death-inducing effects of MET are not MOR-dependent. We recorded doxorubicin and TMZ concentration- response curves in combination with fixed MET concentrations. MET enhanced doxorubicin-induced cytotoxicity in only one cell line, and in primary cells it was observed only in a particular MET concentration range. In all assays, MET was not effective in sensitizing cells to TMZ. In two cell lines, MET even decreased the cell's sensitivity to TMZ.

CONCLUSION

MET was found to be cytotoxic in GBM cells in vitro only at high, clinically not relevant concentrations, where it was effective in inducing apoptosis and necrosis. Sensitizing effects were only observed in combination with doxorubicin, but not with TMZ, and are dependent on cell line and the applied drug concentration. Therefore, our findings do not support the use of MET in the treatment of GBM in combination with TMZ, as no sensitizing effect of MET was observed.

Liquid Chromatography-High-Resolution Mass Spectrometry-Based In Vitro Toxicometabolomics of the Synthetic Cathinones 4-MPD and 4-MEAP in Pooled Human Liver Microsomes

Synthetic cathinones belong to the most often seized new psychoactive substances on an international level. This study investigated the toxicometabolomics, particularly the in vitro metabolism of 2-(methylamino)-1-(4-methylphenyl)-1-pentanone (4-MPD) and 2-(ethylamino)-1-(4-methylphenyl)-1-pentanone (4-MEAP) in pooled human liver microsomes (pHLM) using untargeted metabolomics techniques. Incubations were performed with the substrates in concentrations ranging from 0, 12.5, and 25 µM. Analysis was done by means of high-performance liquid chromatography coupled to high-resolution mass spectrometry (HPLC-HRMS/MS) in full scan only and the obtained data was evaluated using XCMS Online and MetaboAnalyst. Significant features were putatively identified using a separate parallel reaction monitoring method. Statistical analysis was performed using Kruskal-Wallis test for prefiltering significant features and subsequent hierarchical clustering, as well as principal component analysis (PCA). Hierarchical clustering or PCA showed a distinct clustering of all concentrations with most of the features z-scores rising with the concentration of the investigated substances. Identification of significant features left many of them unidentified but revealed metabolites of both 4-MPD and 4-MEAP. Both substances formed carboxylic acids, were hydroxylated at the alkyl chain, and formed metabolites after combined hydroxylation and reduction of the cathinone oxo group. 4-MPD additionally formed a dihydroxy metabolite and a hydroxylamine. 4-MEAP was additionally found reduced at the cathinone oxo group, N-dealkylated, and formed an oxo metabolite. These findings are the first to describe the metabolic pathways of 4-MPD and to extend our knowledge about the metabolism of 4-MEAP. Findings, particularly the MS data of the metabolites, are essential for setting up metabolite-based toxicological (urine) screening procedures.

Toxicokinetics and Analytical Toxicology of Flualprazolam: Metabolic Fate, Isozyme Mapping, Human Plasma Concentration and Main Urinary Excretion Products

An increasing number of benzodiazepine-type compounds are appearing on the new psychoactive substances market. 8-Chloro-6-(2-fluorophenyl)-1-methyl-4H-[1,2,4]triazolo[4,3-a][1,4]benzodiazepine (well known as flualprazolam) represents a potent ‘designer benzodiazepine’ that has been associated with sedation, loss of consciousness, memory loss and disinhibition. The aims of the present study were to tentatively identify flualprazolam metabolites using in vitro incubations with pooled human liver S9 fraction or HepaRG cells by means of liquid-chromatography-high resolution tandem mass spectrometry. Isozymes involved in phase I and II biotransformation were identified in vitro. Results were then confirmed using human biosamples of an 18-year old male who was admitted to the emergency department after suspected flualprazolam ingestion. Furthermore, the plasma concentration was determined using the standard addition method. Seven flualprazolam metabolites were tentatively identified. Several cytochrome P450 and UDP-glucuronosyltransferase isozymes, amongst them CYP3A4 and UGT1A4, were shown to be involved in flualprazolam biotransformation reactions, and an influence of polymorphisms as well as drug–drug or drug–food interactions cannot be excluded. Alpha-hydroxy flualprazolam glucuronide, 4-hydroxy flualprazolam glucuronide and the parent glucuronide were identified as most abundant signals in urine, far more abundant than the parent compound flualprazolam. These metabolites are thus recommended as urine-screening targets. If conjugate cleavage was performed during sample preparation, the corresponding phase I metabolites should be added as targets. Both hydroxy metabolites can also be recommended for blood screening. The flualprazolam plasma concentration determined in the intoxication case was as low as 8 μg/L underlining the need of analytical methods with sufficient sensitivity for blood-screening purposes.

The metabolic fate of two new psychoactive substances - 2-aminoindane and N-methyl-2-aminoindane - studied in vitro and in vivo to support drug testing

The aim of this study was to characterize the in vitro and in vivo metabolism of 2-aminoindane (2,3-dihydro-1H-inden-2-amine, 2-AI), and N-methyl-2-aminoindane (N-methyl-2,3-dihydro-1H-inden-2-amine, NM-2-AI) after incubations using pooled human liver microsomes (pHLMs), pooled human liver S9 fraction (pS9), and rat urine after oral administration. After analysis using liquid chromatography coupled to high-resolution mass spectrometry, pHLM incubations revealed that 2-AI was left unmetabolized, while NM-2-AI formed a hydroxylamine and diastereomers of a metabolite formed after hydroxylation in beta position. Incubations using pS9 led to the formation of an acetyl conjugation in the case of 2-AI and merely a hydroxylamine for NM-2-AI. Investigations on rat urine showed that 2-AI was hydroxylated also forming diasteromers as described for NM-2-AI or acetylated similar to incubations using pS9. All hydroxylated metabolites of NM-2-AI except the hydroxylamine were found in rat urine as additional sulfates. Assuming similar patterns in humans, urine screening procedures might be focused on the parent compounds but should also include their metabolites. An activity screening using human recombinant N-acetyl transferase (NAT) isoforms 1 and 2 revealed that 2-AI was acetylated exclusively by NAT2, which is polymorphically expressed.

Reduced longitudinal cardiac strain in asthma patients

OBJECTIVE

There is limited knowledge about the potential relationship between asthma and heart function. Aim of our present study was to examine if asthma may be associated with manifest or subclinical heart dysfunction.

METHODS

Seventy-two allergic mild-to-moderate and severe asthma patients and 20 matched controls were enrolled in the study. Depending on the anti-asthmatic therapy, four subgroups of asthma patients were created: patients under long-acting beta2-agonists (LABA) and inhaled cortisone without oral cortisone treatment with (1a) versus without (1b) additional omalizumab therapy; patients with LABA, inhaled cortisone and omalizumab treatment with (2a) versus without (2b) oral cortisone. Standard echocardiographic parameters as well as global longitudinal left and right ventricular strains as determined by ultrasound-based speckle-tracking method were evaluated. Furthermore, NT-pro-brain natriuretic peptide (NT-pro-BNP), immunoglobulin E (IgE), C-reactive protein (CRP), and blood count were assessed in asthma and control groups.

RESULTS

There were no relevant differences in standard echocardiographic measures between both asthma groups and the control collective. Longitudinal left ventricular strain values were reduced significantly in severe and mild-to-moderate asthma groups (-12.91 ± 0.84% and -13.92 ± 1.55%, respectively), whereas longitudinal right ventricular strain values were additionally relevantly decreased in severe asthma (-10.35 ± 1.04%) compared to the control (-16.55 ± 0.49% and -18.48 ± 1.90%, respectively). Cardiac strains were similar in subgroups 1a and 1b. In contrast, patients from subgroup 2a presented reduced heart strains and decreased lung function compared to those from 2b. CRP, IgE, and eosinophils were significantly increased in asthma versus control individuals.

CONCLUSIONS

Allergic asthma, especially severe asthma is associated with subclinical impaired left and right ventricular function as determined by speckle-tracking analysis.

Inhibition of the PI3K but not the MEK/ERK pathway sensitizes human glioma cells to alkylating drugs

Background

Intrinsic chemoresistance of glioblastoma (GBM) is frequently owed to activation of the PI3K and MEK/ERK pathways. These signaling cascades are tightly interconnected however the quantitative contribution of both to intrinsic resistance is still not clear. Here, we aimed at determining the activation status of these pathways in human GBM biopsies and cells and investigating the quantitative impact of both pathways to chemoresistance.

Methods

Receptor tyrosine kinase (RTK) pathways in temozolomide (TMZ) treatment naive or TMZ resistant human GBM biopsies and GBM cells were investigated by proteome profiling and immunoblotting of a subset of proteins. Resistance to drugs and RTK pathway inhibitors was assessed by MTT assays. Apoptotic rates were determined by Annexin V staining and DNA damage with comet assays and immunoblotting.

Results

We analyzed activation of RTK pathways by proteome profiling of tumor samples of patients which were diagnosed a secondary GBM and underwent surgery and patients which underwent a second surgery after TMZ treatment due to recurrence of the tumor. We observed substantial activation of the PI3K and MEK/ERK pathways in both groups. However, AKT and CREB phosphorylation was reduced in biopsies of resistant tumors while ERK phosphorylation remained unchanged. Subsequent proteome profiling revealed that multiple RTKs and downstream targets are also activated in three GBM cell lines. We then systematically describe a mechanism of resistance of GBM cell lines and human primary GBM cells to the alkylating drugs TMZ and cisplatin. No specific inhibitor of the upstream RTKs sensitized cells to drug treatment. In contrast, we were able to restore sensitivity to TMZ and cisplatin by inhibiting PI3K in all cell lines and in human primary GBM cells. Interestingly, an opposite effect was observed when we inhibited the MEK/ERK signaling cascade with two different inhibitors.

Conclusions

Temozolomide treatment naive and TMZ resistant GBM biopsies show a distinct activation pattern of the MEK/ERK and PI3K signaling cascades indicating a role of these pathways in resistance development. Both pathways are also activated in GBM cell lines, however, only the PI3K pathway seems to play a crucial role in resistance to alkylating agents and might serve as drug target for chemosensitization.

Is sunitinib a Narrow Therapeutic Index Drug? - A systematic review and in vitro toxicology-analysis of Sunitinib vs. Imatinib in cells from different tissues

Narrow Therapeutic Index Drugs (NTIDs) are characterized by a small range between therapeutic and toxicological effect. Missing international harmonized definition for NTIDs the EMA does not even have a definition of NTIDs in contrast to the U.S. FDA, Health Canada, and the Japanese NIHS. Sunitinib, a tyrosine kinase inhibitor (TKI), indicated for the treatment of certain cancer types, will be running off-patent soon. Falling into the category of NTID would have a major impact on regulatory requirements for generic applications. Our analyses of metadata revealed numerous arguments in favor of a NTID designation. We used in vitro experiments to also give initial experimental answers. Five cell types of different tissue origin were examined for determination of IC50-values in cell viability assays. For comparison, the first-in-class TKI Imatinib was used as reference non-NTID drug. In addition, apoptotic proteins were investigated with respect to their expression and phosphorylation status. These in vitro experiments showed systematically higher toxicity of Sunitinib compared to Imatinib and a different expression and phosphorylation pattern of apoptotic proteins. In vitro data can only give preliminary results and further experiments with clinical blood samples and tumor biopsies are needed to finally clarify NTID status of Sunitinib.

Efficacy, safety and regulatory status of SGLT2 inhibitors: focus on canagliflozin

Prevalence of diabetes mellitus is inc6reasing, with a burden of 382 million patients worldwide at present (more than the entire US population). The International Diabetes Federation anticipates an increase up to 592 million patients by 2035. Another major problem arises from the fact that just 50% of patients with type 2 diabetes mellitus are at target glycaemic control with currently available medications. Therefore, a clear need for new therapies that aim to optimize glycaemic control becomes evident. Renal sodium-linked glucose transporter 2 inhibitors are new antidiabetic drugs with an insulin-independent mechanism of action. They pose one remarkable advantage compared with already established antidiabetics: increasing urinary glucose excretion without inducing hypoglycaemia, thereby promoting body weight reduction due to loss of ~300 kcal per day. This review focuses on canagliflozin, which was the first successful compound of this class to be approved by both the US Food and Drug Administration and the European Medicines Agency in 2013. Clinical trials showed promising results: enhancing glycaemic control was paralleled by reducing body weight and systolic and diastolic blood pressure. Nevertheless, some safety concerns remain, such as genital mycotic infections, urinary tract infections and cardiovascular risks in vulnerable patients, which will be closely monitored in several post-authorization safety studies.

Clinical pharmacology and regulatory consequences of GnRH analogues in prostate cancer

INTRODUCTION

GnRH (gonadotropin-releasing hormone) analogues are long-term known to be safe and effective in the clinical management of hormone-dependent advanced prostate cancer. However, their unusual mechanism of action of de-sensitizing pituitary receptors makes generic market entry challenging. In addition, safety aspects like initial flare-up, breakthrough escape, and miniflares render planning and organization of clinical registration trials a complex project.

REGULATORY REQUIREMENTS THERAPEUTIC EQUIVALENCE

Regulatory requirements are high as these medicines are compared to bilateral surgical castration with a 100% success rate. GnRH analogues will be used probably even wider in the near future due to demographic development and extension of indications. However, they are challenged by their antagonistic counterparts, which are avoiding flare-up phenomena. The following article deals with regulatory requirements of GnRH analogues in regard to their clinical characteristics.

Clinical pharmacology of tyrosine kinase inhibitors becoming generic drugs: the regulatory perspective

Over the last decades, billions have been spent and huge efforts have been taken in basic and clinical cancer research [CA Cancer J Clin63:11-30]. About a decade ago, the arms race between drugs and cancer cells reached a new level by introduction of tyrosine kinase inhibitors (TKI) into pharmacological anti-cancer therapy. According to their molecular mechanism of action, TKI in contrast to so-called "classic" or "conventional" cytostatics belong to the group of targeted cancer medicines, characterized by accurately fitting with biological structures (i.e. active centers of kinases). Numerous (partly orphan) indications are covered by this new class of substances. Approximately ten years after the first substances of this class of medicines were authorized, patent protection will end within the next years. The following article covers clinical meaning and regulatory status of anti-cancer TKI and gives an outlook to what is expected from the introduction of generic anti-cancer TKI.

Targeting adipose tissue

Two different types of adipose tissues can be found in humans enabling them to respond to starvation and cold: white adipose tissue (WAT) is generally known and stores excess energy in the form of triacylglycerol (TG), insulates against cold, and serves as a mechanical cushion. Brown adipose tissue (BAT) helps newborns to cope with cold. BAT has the capacity to uncouple the mitochondrial respiratory chain, thereby generating heat rather than adenosine triphosphate (ATP). The previously widely held view was that BAT disappears rapidly after birth and is no longer present in adult humans. Using positron emission tomography (PET), however, it was recently shown that metabolically active BAT occurs in defined regions and scattered in WAT of the adult and possibly has an influence on whole-body energy homeostasis. In obese individuals adipose tissue is at the center of metabolic syndrome. Targeting of WAT by thiazolidinediones (TZDs), activators of peroxisome proliferator-activated receptor γ (PPARγ) a 'master' regulator of fat cell biology, is a current therapy for the treatment of type 2 diabetes. Since its unique capacity to increase energy consumption of the body and to dissipate surplus energy as heat, BAT offers new perspectives as a therapeutic target for the treatment of obesity and associated diseases such as type 2 diabetes and metabolic syndrome. Recent discoveries of new signaling pathways of BAT development give rise to new therapeutic possibilities in order to influence BAT content and activity.

[Platinum-based chemotherapy in triple negative breast cancer]

Since its first market authorisation 40 years ago, cisplatin is an important constituent of cytostatic chemotherapy regimens. Some tumour entities even lost their fright after introduction of cisplatin into the therapeutic armamentarium. For instance, cure rates of up to 95 % are reported for testicular cancer depending on the tumour-stage at the time of diagnosis. In the first-line breast cancer therapy cisplatin is regarded only a cytostatic reserve at present. However, platinum-based therapy regimes are widely used in anthracyclin- and/or taxan-refractory situations. In addition, platinum-based therapy is well-established in the palliative treatment of breast cancer.Breast cancer is the most common female cancer type and triple negative breast cancer (TNBC) has the poorest prognosis. Therapy options are limited to surgery, radiotherapy, and polychemotherapy since targeted therapies, which are based on a molecular interaction with a target protein, are not amenable at present. However, triple negative breast cancer specimens show good initial response to platinum-based chemotherapy. Therefore, clinical research of cisplatin therapy in BRCA-mutated triple negative breast cancer is currently intensified. However, despite successful first treatment, the tumour often reappears quickly, a phenomenon designated as the triple negative paradox. Throughout this article, current indications and possible future development to a potentially new indication is outlined.

Platinum resistance in breast and ovarian cancer cell lines

Breast and ovarian cancers are among the 10 leading cancer types in females with mortalities of 15% and 6%, respectively. Despite tremendous efforts to conquer malignant diseases, the war on cancer declared by Richard Nixon four decades ago seems to be lost. Approximately 21,800 women in the US will be diagnosed with ovarian cancer in 2011. Therefore, its incidence is relatively low compared to breast cancer with 207.090 prognosed cases in 2011. However, overall survival unmasks ovarian cancer as the most deadly gynecological neoplasia. Platinum-based chemotherapy is emerging as an upcoming treatment modality especially in triple negative breast cancer. However, in ovarian cancer Platinum-complexes for a long time are established as first line treatment. Emergence of a resistant phenotype is a major hurdle in curative cancer therapy approaches and many scientists around the world are focussing on this issue. This review covers new findings in this field during the past decade.

Y-Box–Binding Protein YB-1 Identifies High-Risk Patients With Primary Breast Cancer Benefiting From Rapidly Cycled Tandem High-Dose Adjuvant Chemotherapy

Purpose

To investigate the potential of Y-box–binding protein YB-1, a multifunctional protein linked to tumor aggressiveness and multidrug resistance, to identify patients with breast cancer likely to benefit from dose-intensified chemotherapy regimens.

Patients and Methods

YB-1 was immunohistochemically determined in 211 primary tumors from the prospective, randomized West German Study Group WSG-AM-01 trial in high-risk (≥ 10 involved lymph-nodes) breast cancer (HRBC). Predictive impact of YB-1 was assessed by multivariate survival analysis, including time-varying factor-therapy interactions.

Results

At median follow-up of 61.7 months, patients receiving rapidly cycled tandem high-dose therapy (HD; two cycles [2×] epirubicin 90 mg/m2 and cyclophosphamide 600 mg/m2 every 14 days, followed by 2× epirubicin 90 mg/m2, cyclophosphamide 3,000 mg/m2, and thiotepa 400 mg/m2 every 21 days) had better disease-free survival (DFS; hazard ratio [HR] = 0.62; 95% CI, 0.44 to 0.89) and overall survival (OS; HR = 0.59; 95% CI, 0.4 to 0.89) than those receiving conventional dose-dense chemotherapy (DD; 4× epirubicin 90 mg/m2 and cyclophosphamide 600 mg/m2, followed by 3× cyclophosphamide 600 mg/m2, methotrexate 40 mg/m2, and fluorouracil 600 mg/m2 every 14 days). High YB-1 was associated with aggressive tumor phenotype (negative steroid hormone receptor status, positive human epidermal growth factor receptor 2 and p53 status, high MIB-1, unfavorable tumor grade) and poor OS (median 78 v 97 months; P = .01). In patients with high YB-1, HD yielded a 63-month median DFS (P = .001) and a 46-month median OS advantage (P = .002) versus DD. In multivariate models, patients with high B-1 receiving HD (v DD) had one third the hazard rate after 20 months for DFS and one sixth after 40 months for OS.

Conclusion

In a randomized prospective cancer therapy trial, for the first time, a strong predictive impact of YB-1 on survival has been demonstrated: enhanced benefit from HD (v DD) therapy occurs in HRBC with high YB-1. Future trials could therefore address optimal chemotherapeutic strategies,taking YB-1 into account.

NF546 [4,4'-(carbonylbis(imino-3,1-phenylene-carbonylimino-3,1-(4-methyl-phenylene)-carbonylimino))-bis(1,3-xylene-alpha,alpha'-diphosphonic acid) tetrasodium salt] is a non-nucleotide P2Y11 agonist and stimulates release of interleukin-8 from human monocyte-derived dendritic cells

The G protein-coupled P2Y(11) receptor is involved in immune system modulation. In-depth physiological evaluation is hampered, however, by a lack of selective and potent ligands. By screening a library of sulfonic and phosphonic acid derivatives at P2Y(11) receptors recombinantly expressed in human 1321N1 astrocytoma cells (calcium and cAMP assays), the selective non-nucleotide P2Y(11) agonist NF546 [4,4'-(carbonylbis(imino-3,1-phenylene-carbonylimino-3,1-(4-methyl-phenylene)carbonylimino))-bis(1,3-xylene-alpha,alpha'-diphosphonic acid) tetrasodium salt] was identified. NF546 had a pEC(50) of 6.27 and is relatively selective for P2Y(11) over P2Y(1), P2Y(2), P2Y(4), P2Y(6), P2Y(12), P2X(1), P2X(2), and P2X(2)-X(3). Adenosine-5'-O-(3-thio)triphosphate (ATPgammaS), a nonhydrolyzable analog of the physiological P2Y(11) agonist ATP, and NF546 use a common binding site as suggested by molecular modeling studies and their competitive behavior toward the nanomolar potency antagonist NF340 [4,4'-(carbonylbis(imino-3,1-(4-methyl-phenylene)carbonylimino))bis(naphthalene-2,6-disulfonic acid) tetrasodium salt] in Schild analysis. The pA(2) of NF340 was 8.02 against ATPgammaS and 8.04 against NF546 (calcium assays). NF546 was further tested for P2Y(11)-mediated effects in monocyte-derived dendritic cells. Similarly to ATPgammaS, NF546 led to thrombospondin-1 secretion and inhibition of lipopolysaccharide-stimulated interleukin-12 release, whereas NF340 inhibited these effects. Further, for the first time, it was shown that ATPgammaS or NF546 stimulation promotes interleukin 8 (IL-8) release from dendritic cells, which could be inhibited by NF340. In conclusion, we have described the first selective, non-nucleotide agonist NF546 for P2Y(11) receptors in both recombinant and physiological expression systems and could show a P2Y(11)-stimulated IL-8 release, further supporting the immunomodulatory role of P2Y(11) receptors.

Hyperactivation of the insulin-like growth factor receptor I signaling pathway is an essential event for cisplatin resistance of ovarian cancer cells

Platinum plays a central role in the therapy of ovarian cancer, and the emergence of platinum resistance is a major obstacle for clinical management of the disease. We treated A2780 ovarian cancer cells by weekly cycles of cisplatin over a period of 6 months and unveiled that enhanced insulin-like growth factor I receptor (IGF-IR) expression and autocrine IGF-I are associated with hyperactivation of the IGF-IR and phosphatidylinositol-3-OH kinase (PI3K) pathways in cisplatin-resistant cells. IGF-IR expression levels increased during treatment cycles and correlated with cisplatin resistance. Purified IGF-I induced cisplatin resistance in diverse ovarian cancer cell lines, and small molecule inhibitors proved that IGF-IR and PI3K are essential for cisplatin resistance. Similar results were obtained with BG-1 ovarian cancer cells. Cytogenetic and array comparative genomic hybridization analyses revealed selection and de novo formation of chromosomal alterations during resistance development. An analysis of gene expression profiles of primary ovarian carcinomas identified the regulatory subunit PIK3R2 of PI3-kinase as a significant negative prognosis factor for ovarian cancer. We conclude that targeting the IGF-IR and the PI3K pathways is a promising new strategy to treat cisplatin-resistant ovarian carcinomas.

Epidermal growth factor receptor pathway analysis identifies amphiregulin as a key factor for cisplatin resistance of human breast cancer cells

The use of platinum complexes for the therapy of breast cancer is an emerging new treatment modality. To gain insight into the mechanisms underlying cisplatin resistance in breast cancer, we used estrogen receptor-positive MCF-7 cells as a model system. We generated cisplatin-resistant MCF-7 cells and determined the functional status of epidermal growth factor receptor (EGFR), MAPK, and AKT signaling pathways by phosphoreceptor tyrosine kinase and phospho-MAPK arrays. The cisplatin-resistant MCF-7 cells are characterized by increased EGFR phosphorylation, high levels of AKT1 kinase activity, and ERK1 phosphorylation. In contrast, the JNK and p38 MAPK modules of the MAPK signaling pathway were inactive. These conditions were associated with inactivation of the p53 pathway and increased BCL-2 expression. We investigated the expression of genes encoding the ligands for the ERBB signaling cascade and found a selective up-regulation of amphiregulin expression, which occurred at later stages of cisplatin resistance development. Amphiregulin is a specific ligand of the EGFR (ERBB1) and a potent mitogen for epithelial cells. After exposure to cisplatin, the resistant MCF-7 cells secreted amphiregulin protein over extended periods of time, and knockdown of amphiregulin expression by specific short interfering RNA resulted in a nearly complete reversion of the resistant phenotype. To demonstrate the generality and importance of our findings, we examined amphiregulin expression and cisplatin resistance in a variety of human breast cancer cell lines and found a highly significant correlation. In contrast, amphiregulin levels did not significantly correlate with cisplatin resistance in a panel of lung cancer cell lines. We have thus identified a novel function of amphiregulin for cisplatin resistance in human breast cancer cells.

In vitro differentiation of human dental follicle cells with dexamethasone and insulin

The dental follicle is an ectomesenchymally derived connective tissue harboring precursor cells for the tooth supporting apparatus. In this study, we examined gene expression of freshly isolated human dental follicle cells during osteogenic differentiation in vitro. These plastic adherent fibroblastic cells express Notch-1, nestin and vimentin. We differentiated dental follicle cells with dexamethasone or insulin-based protocols into membrane-like structures containing mineralizing foci. An analysis of mineralized tissue with atomic force microscopy illustrated a bone and cementum-like structure. A real-time RT-PCR analysis was developed to investigate expression of typical osteoblast or cementoblast related genes during differentiation. Gene expressions of osteocalcin (OCN), bone morphogenic protein (BMP)-2 and nestin were increased during the both differentiation approaches. Our work demonstrates differentiation of dental follicle cells with an insulin-based protocol for the first time.

Pharmacological characterization of the benz[d]indolo[2,3-g]azecine LE300, a novel type of a nanomolar dopamine receptor antagonist

LE300 (7-methyl-6,7,8,9,14,15-hexahydro-5 H-benz[d]indolo[2,3-g]azecine), a previously reported subnanomolar antagonist at rat striatal dopamine D1 receptors, and three of its azecine-N-substituted congeners combining structural elements of serotonin and dopamine were comprehensively characterised (binding and function) at recombinant human dopamine receptors. Radioligand competition experiments at D1 and D2L receptors were performed by using [(3)H]SCH23390 and [(3)H]spiperone, respectively. Functional assays included measurements of cAMP, intracellular [Ca(2+)], and [(35)S]GTPgammaS-binding. LE300 was the most potent compound with a 10- to 20-fold selectivity for D1 over D2L receptors as measured in equilibrium binding experiments [competition radioligand binding: K(i)(D1)=1.9 nM, K(i)(D2L)=44.7 nM; [(35)S]GTPgammaS-binding: K(i)(D1)=1.8 nM, K(i)(D2L)=21.5 nM]. In functional (non-equilibrium) experiments, LE300 did not reveal a D1 over D2L selectivity but retained nanomolar K(i) values at human dopamine receptors (measurement of cAMP: K(i)(D1)=25.9 nM, K(i)(D2L)=5.2 nM; measurement of intracellular [Ca(2+)]: K(i)(D1)=60.4 nM, K(i)(D2L)=19.0 nM). LE300 is currently under investigation for usefulness as positrone emission tomography ligand. In conclusion, LE300 is a novel type of a nanomolar dopamine receptor antagonist combining structural core elements of dopamine and serotonin, and may become useful as positrone emission tomography ligand.

Functional screening of G protein-coupled receptors by measuring intracellular calcium with a fluorescence microplate reader

Ligand binding studies reveal information about affinity to G protein-coupled receptors (GPCRs) rather than functional properties. Increase in intracellular Ca(2+) appears to represent a universal second messenger signal for a majority of recombinant GPCRs. Here, we exploit Ca(2+) signaling as a fast and sensitive functional screening method for a number of GPCRs coupled to different G proteins. Ca(2+) fluorescence measurements are performed using Oregon Green 488 BAPTA-1/AM and a microplate reader equipped with an injector. Buffer alone or test compounds dissolved in buffer are injected into a cell suspension, and fluorescence intensity is recorded for 30 s. Each of the GPCRs tested--G(q)-coupled P2Y(2), G(s)-coupled dopamine D1 and D5, G(i)-coupled dopamine D2L, and G(q/11)-coupled muscarinic acetylcholine M1--yielded a significant rise in intracellular free [Ca(2+)] on agonist stimulation. Agonist stimulation was dose dependent, as shown for ATP or UTP stimulation of P2Y(2) receptors (EC(50) = 1 microM), SKF38393 stimulation of hD1 and hD5 (EC(50) = 18.1 nM and 2.7 nM), and quinpirole at hD2L (EC(50) = 6.5 nM). SCH23390 (at hD1 and hD5) and spiperone, haloperidol, and clozapine (at hD2L) competitively antagonized the Ca(2+) response. Furthermore, the Ca(2+) assay served to screen suramin analogs for antagonistic activity at P2Y(2) receptors. Screening at dopamine receptors revealed LE300, a new lead for a dopamine receptor antagonist. Advantages of the assay include fast and simple 96- or 384-well plate format (high-throughput screening), use of a visible light-excitable fluorescent dye, applicability to a majority of GPCRs, and simultaneous analysis of distinct Ca(2+) fluxes.

Allosteric modulation of muscarinic receptor signaling: alcuronium-induced conversion of pilocarpine from an agonist into an antagonist

Previous studies on allosteric interactions at muscarinic receptors have often focused on ligand-receptor binding interactions, because ligand binding seemed to reflect functional consequences. The prototypal allosteric agent alcuronium is known to bind with similar affinity to the M(2) subtype of muscarinic acetylcholine receptors whether or not the receptors are occupied by the agonist pilocarpine. To determine allosteric modulation of receptor signaling by alcuronium, the effects of pilocarpine were measured in contracting guinea pig left atria and on G-protein coupling in M(2)-transfected Chinese hamster ovary (CHO) cell membranes. Alcuronium dose-dependently suppressed pilocarpine-induced reduction of isometric contraction force in atria (pIC(50, Alc) = 5.63) without any effect on the EC(50) of pilocarpine, consistent with an allosteric mechanism. In contrast, alcuronium shifted the concentration-effect curve of the agonist oxotremorine M to the right without affecting the maximal effect, in a formally competitive manner (pK(A, Alc) = 5.54). If pilocarpine remained receptor bound in the presence of alcuronium, this indicates that pilocarpine can no longer act as an agonist. In support of this hypothesis, pilocarpine acted as a competitive antagonist against oxotremorine M in the presence of 10 microM alcuronium. Measuring guanosine 5'-O-(3-[(35)S]thio)triphosphate ([(35)S]GTPgammaS) binding in CHO-M(2) membranes yielded similar results. Alcuronium suppressed pilocarpine-induced stimulation of [(35)S]GTPgammaS binding (pIC(50, Alc) = 5.47) without shift in EC(50), whereas it competitively shifted the response to oxotremorine M (pK(A, Alc) = 5.97). [(3)H]Oxotremorine M binding data corresponded with the functional findings. In conclusion, alcuronium converted the agonist pilocarpine into an antagonist-a novel type of functional allosteric interaction.

Hormonal regulation of peripheral benzodiazepine receptor binding properties is mediated by subunit interaction

The peripheral benzodiazepine receptor (PBR) is composed of three subunits with molecular masses of 18, 30, and 32 kDa. Many physiological functions have been attributed to the PBR, including regulation of steroidogenesis. Furthermore, the PBR itself is under hormonal regulation. In the current study, we investigated the role of female gonadal sex hormones in the regulation of PBR expression in steroidogenic and nonsteroidogenic tissues. To accomplish this, adult female rats were pharmacologically castrated using chronic administration of the gonadotropin-releasing hormone agonist decapeptyl (triptorelin-D-Trp(6)-LHRH). Half of these rats received 17beta-estradiol as hormone replacement, while a control group received daily injections of vehicle only. We found that PBR binding capacity dropped by 40 and 48% in ovaries and adrenals, respectively, following decapeptyl administration, as opposed to no change in the kidney. This down-regulation of PBR densities was prevented by estradiol replacement. We did not find evidence for transcriptional, posttranscriptional, and translational mechanisms in this decapeptyl-induced down-regulation. In contrast, immunoprecipitation of the PBR complex, using antibodies against the 18- and 32-kDa subunits of the complex, demonstrated that there were changes in PBR subunit interactions, consistent with the down-regulation of PBR binding capacity. These findings represent a novel hormone-dependent posttranslational regulatory mechanism.

Hormone replacement and simvastatin in the therapy of hypercholesterolemic postmenopausal women

OBJECTIVES

To prospectively investigate the effect of cholesterol lowering diet, hormone replacement therapy and simvastatin on plasma lipid levels using a 3-month stepwise protocol.

METHODS

Participants were postmenopausal women under the age of 60 with hypercholesterolemia (plasma total cholesterol > 240 mg/dl). The study started with 3 months of Step-One diet (phase I) followed by 3 months of diet and hormone replacement therapy (0.625 mg conjugated estrogens daily combined with 5 mg medroxyprogesterone acetate at days 13-25 of each cycle) (phase II). In women whose total cholesterol remained above 240 mg/dl or LDL-cholesterol above 160 mg/dl by the end of phase II, simvastatin at 10 mg daily was added (phase III). Plasma cholesterol levels as well as safety measurements were closely monitored.

RESULTS

Sixteen (21%) of 75 patients who entered the study had satisfactory cholesterol levels by the end of 6 months. Another 25 patients (33%) dropped out of the study for various reasons by that time. In the 34 patients who started simvastatin, plasma total cholesterol levels did not significantly change during phase I and II, however, LDL-cholesterol significantly decreased (204 +/- 31 to 187 +/- 26 mg/dl, p = 0.04) and HDL increased (53 +/- 12 to 62 +/- 16 mg/dl, p = 0.04). A dramatic decrease occurred in both total and LDL-cholesterol levels after one month of phase III (281 +/- 26 to 213 +/- 30 mg/dl 187 +/- 26 to 122 +/- 30 mg/dl respectively, p < 0.0001), with no further changes during the rest of the study period. No significant changes occurred in HDL-cholesterol and triglyceride plasma levels at this phase. Adverse effects were few and minor throughout the study.

CONCLUSIONS

Some of the hypercholesterolemic postmenopausal women will benefit from hormone replacement therapy as a single cholesterol lowering treatment in addition to diet (21% in our series). Nevertheless, combination therapy of estrogens and low dose simvastatin proved to be extremely effective in lowering cholesterol levels with no significant side effects. Such therapeutic regimen may also have a synergistic anti-atherogenic effect.

Hormone replacement therapy enhances postprandial lipid metabolism in postmenopausal women

Postmenopausal estrogen therapy reduces cardiovascular morbidity and mortality, except in women with advanced coronary disease. This beneficial effect is partly attributed to a reduction of fasting plasma total and low-density lipoprotein cholesterol (LDL-C) and an elevation of plasma high-density lipoprotein cholesterol (HDL-C) concentrations. Since postprandial lipemia seems to play a role in the pathogenesis of coronary artery disease, we evaluated the effect of hormone replacement therapy (HRT) on postprandial lipoprotein metabolism in 14 normolipemic postmenopausal women. A vitamin A fat-loading test before and after three cycles of treatment with a sequential combination of conjugated equine estrogen (CEE) and medroxyprogesterone acetate (MPA) was used to label chylomicrons and chylomicron remnants with retinyl palmitate (RP), and RP clearance was assessed over an 8-hour period postprandially. Following 3 months of HRT, fasting total cholesterol and LDL-C levels were reduced 9.8% (P = .049) and 16.5% (P = .023), respectively. Fasting HDL-C levels increased 18.9% (P = .001). Fasting triglycerides (TGs) increased, but not significantly. Postprandial integrated plasma TGs did not change significantly. The integrated RP levels in whole plasma and chylomicron (Svedberg flotation units [Sf] > 1,000) and nonchylomicron (Sf < 1,000) fractions were reduced 58% (P = .043), 78% (P = .041), and 75% (P = .001), respectively, after hormonal treatment. Enhanced clearance of chylomicrons and chylomicron remnants by HRT may contribute to the protective effect of estrogens against cardiovascular disease in normolipemic postmenopausal women.

Effect of estradiol on rat ileum

1. Sex hormones may influence gastrointestinal motility and thus may be responsible for symptoms that are common during pregnancy or hormone replacement therapy. The purpose of this study was to evaluate the effect of estradiol on the gut. 2. Segments of rat ileum (n=9) were suspended in an organ bath and exposed to increasing concentrations of carbachol, in the presence or absence of 17beta-estradiol. 17beta-estradiol markedly reduced the force developed by the ileum in response to carbachol. 3. These results suggest that estradiol reduces gastrointestinal motility.

Fluctuations of lipid and lipoprotein levels in hyperlipidemic postmenopausal women receiving hormone replacement therapy

BACKGROUND

Fluctuations in lipid and lipoprotein levels are encountered quite often in hyperlipidemic patients. We examined the possibility that lipid and lipoprotein levels fluctuate due to the different effects of estrogen and progestogen in postmenopausal hyperlipidemic women receiving combined hormonal replacement therapy.

METHODS

In an open-label study conducted during 3 consecutive hormonal cycles (3 months), levels of fasting total cholesterol, triglycerides, and low (LDLC)- and high-density lipoprotein cholesterol (HDLC) were determined in 36 postmenopausal hyperlipidemic women on day 13 of conjugated equine estrogen (1.25 mg/d) therapy and on day 25 after 12 days of receiving estrogen plus medroxyprogesterone acetate (5 mg/d).

RESULTS

While receiving estrogen and combined therapies, means +/- SD total cholesterol levels increased from 6.50 +/- 0.97 mmol/L (251 +/- 37 mg/dL) to 6.88 +/- 1.42 mmol/L (266 +/- 54 mg/dL) (P<.001); LDLC levels, from 4.05 +/- 1.14 mmol/L (156 +/- 44 mg/dL) to 4.62 +/- 1.36 mmol/L (178 +/- 52 mg/dL) (P<.001). Mean +/- SD HDLC cholesterol levels decreased from 1.44 +/- 0.32 mmol/L (55 +/- 12 mg/dL) to 1.29 +/- 0.28 mmol/L (50 +/- 10 mg/dL) (P<.001); triglyceride levels, from 2.23 +/- 1.03 mmol/L (197 +/- 91 mg/dL) to 2.06 +/- 1.04 mmol/L (182 +/- 92 mg/dL) (P<.001).

CONCLUSIONS

Hyperlipidemic postmenopausal women receiving combined sequential estrogen and progestogen replacement therapy demonstrate very significant fluctuations in their lipid and lipoprotein levels. These fluctuations depend on the hormonal phase, ie, estrogen alone or combined with progestogen.

The effects of sublingual estradiol on left ventricular function at rest and exercise in postmenopausal women: an echocardiographic assessment

OBJECTIVE

To evaluate the acute hemodynamic effects of 4 mg estradiol given sublingually.

DESIGN

Rest and exercise echocardiographies were performed prior to estradiol administration. Then, another set of tests was done post-dose: rest examination at 1 h post-dose, isometric exercise at 65 min post-dose, and dynamic exercise at 100 min post-dose.

RESULTS

The administration of 4 mg sublingual estradiol to 24 postmenopausal women (aged 48-58 years) was followed 60 min post-dose by a surge in mean estradiol serum levels (1759 +/- 704 pg/ml). At rest a slight drop in systolic and diastolic blood pressure was measured after estrogen ingestion: 132 +/- 24 mm Hg versus 127 +/- 21 mm Hg, p < 0.05; 83 +/- 11 mm Hg versus 78 +/- 10 mm Hg, p < 0.02. There were no changes in resting heart rate, double product, or vascular resistance. The left heart cavities became smaller: the left atrium diameter decreased from 33.7 +/- 4 mm to 32.3 +/- 4 mm, p < 0.01; the end-systolic diameter decreased from 24.9 +/- 3 mm to 23.6 +/- 4 mm, p < 0.01; the end-diastolic diameter decreased from 44.5 +/- 4 mm to 42.7 +/- 4 mm, p < 0.01. The peak aortic blood flow velocity fell from 120 +/- 19 cm/s to 116 +/- 22 cm/s (p < 0.05), and the flow velocity integral fell from 26.3 +/- 4 cm to 24.9 +/- 5 cm (p < 0.01); the cardiac output underwent a small change, with borderline significance: 7 +/- 2 L/min versus 6.7 +/- 2 L/min, p = 0.06. Only minor changes in the hemodynamic and echocardiographic parameters were recorded after estrogen for both isometric and dynamic exercises. Analyses were also made for two subgroups: 13 normotensive women were compared with 11 hypertensive women. The post-estrogen decreases in resting blood pressure and in peak blood velocity were observed only in the hypertensive subjects, whereas the changes in heart dimensions and in flow velocity integral were the same in both subgroups.

CONCLUSIONS

Sublingual estradiol was associated with acute hemodynamic alterations mainly at rest but also after exercise.

Exercise echocardiography in postmenopausal hormone users with mild systemic hypertension

Rest and exercise echocardiography (at dynamic and isometric exercise) were performed in 30 postmenopausal women (aged 54 +/- 4 years) with borderline to mild hypertension. They were then divided into 2 groups: 17 women who started oral hormone replacement therapy (0.625 mg/day conjugated estrogens or 2 mg/day estradiol) and a control group of 13 nonusers. After 6 to 9 months, a second echocardiography was performed in 26 women (4 withdrew). There were only a few changes in values obtained in the 12 controls at the end of follow-up compared with baseline. Primarily, these changes included a slight decrease in systolic blood pressure at rest and on exercise. Several significant morphologic and hemodynamic alterations appeared in 14 hormone users. Left ventricular cavity dimensions and mass became smaller: mean end-diastolic diameter decreased from 45.9 +/- 3 mm at baseline to 44.4 +/- 3 mm at study termination (p = 0.007). The corresponding values for end-systolic diameter were 25.8 +/- 4 mm and 23.9 +/- 4 mm (p = 0.006); for left atrium diameter, it was 34.5 +/- 4 mm and 32.5 +/- 4 mm (p = 0.001); for left ventricular wall width, it was 19.9 +/- 2 mm and 19.3 +/- 2 mm (p = 0.02); for left ventricular mass, it was 197 +/- 28 g and 179 +/- 32 g (p = 0.006). The resting aortic blood flow velocity and acceleration increased: 119 +/- 18 cm/s before therapy versus 129 +/- 23 cm/s while on hormone substitution (p = 0.04), and 13.6 +/- 3 m/s2 versus 16.5 +/- 4 m/s2 (p = 0.008), respectively. Mean rest to peak exercise systolic blood pressure difference became smaller after hormones: 39 +/- 19 mm Hg versus 28 +/- 13 mm Hg (p = 0.03) during dynamic exercise, and 43 +/- 22 mm Hg versus 25 +/- 13 mm Hg (p = 0.004) during isometric exercise. The above data probably indicate that with hormone replacement therapy, there is an improvement in cardiac function both at rest and during exercise.

Genetic relationship between dopamine transporter gene and schizophrenia: linkage and association

This study explores the genetic relationship between schizophrenia and the dopamine transporter gene (DAT) by a variety of methods. In a sample of 48 families--each family containing at least one nuclear family with a pair of affected siblings--we performed linkage analysis using the maximum likelihood (LOD score) method as well as sibpair analysis (identity by descent). In addition, we investigated a sample of 108 nuclear families--index case affected with schizophrenia/chronic schizoaffective disorder--for association using the haplotype relative risk method. Linkage between schizophrenia and DAT using two- and three-point linkage analysis was excluded with all disease models employed. No evidence for association between haplotypes of the VNTR-probe of the DAT and schizophrenia has been detected. Thus, a contribution of the DAT gene to the genetic diathesis of schizophrenia is unlikely in the families studied.

A case of hypergonadotrophinaemia associated with very high isolated concentrations of immunologically and biologically active luteinizing hormone

A very rare case of a menstruating infertile woman with isolated luteinizing hormone (LH) hypergonadotrophinaemia is presented. There were no signs indicating the presence of a pituitary microadenoma, and LH had normal bioactivity and normal molecular weight. Likewise, no mutation was detected in the coding region of the LH beta-chain gene. In a non-stimulated cycle and a clomiphene citrate cycle, the patient developed an unruptured cyst. The patient ovulated and conceived twice following the addition of human chorionic gonadotrophin. A partial resistance at the ovarian LH receptor site, perhaps caused by a mutation, is a possible explanation for these findings. Another possibility is a malfunction in the signal transduction system of LH beyond the receptor level.

Acute effects of 17 beta-estradiol on the rat heart

OBJECTIVE

Our purpose was to study the acute effects of 17 beta-estradiol on mechanical and electrical activities of cardiac function and on coronary arteries in the rat heart.

STUDY DESIGN

The effects of 17 beta-estradiol were studied on perfused working heart isolated from Charles River male rats. Heart rates, coronary flow, aortic flow, and left ventricular pressure were measured. To avoid coronary interaction, chronotropic and inotropic effects were also tested on isolated atria. Data were analyzed with the paired Student t test.

RESULTS

17 beta-Estradiol produced a dose-dependent negative chronotropic effect in right atria but did not affect the contractility of left atria. A decrease in heart rate was also observed in perfused hearts treated with 5 x 10(-6) mol/L 17 beta-estradiol. 17 beta-Estradiol (5 x 10(-6) mol/L) significantly increased coronary flow (p < 0.005) but had a negligible effect on cardiodynamic index values. A significant effect of 17 beta-estradiol on cardiac function was observed when coronary arteries were precontracted with acetylcholine.

CONCLUSION

Both the experimental coronary vasodilatory effect and the negative chronotropic effect of 17 beta-estradiol support the clinical observations that suggest that this hormone may have an important role in prevention of cardiovascular diseases.

The effect of the hypoestrogenic state, induced by gonadotropin-releasing hormone agonist, on Doppler-derived parameters of aortic flow

The effect of the hypoestrogenic state, induced by a GnRH agonist (GnRH-a), on cardiac function in healthy young women, was evaluated by Doppler echocardiography performed before treatment and when serum 17 beta-estradiol levels were suppressed by GnRH-a to 36.7 pmol/L. The following parameters of aortic flow were measured: peak flow velocity, ejection time, and acceleration time. Additional parameters calculated were flow velocity integral, cardiac index, and mean acceleration. The study group included 15 menstruating women, aged 25-42 yr (mean, 33 yr), with symptomatic fibroids, endometriosis, or scheduled for in vitro fertilization, who were treated with a GnRH-a. There were significant decreases in peak flow velocity (99 +/- 11 vs. 86 +/- 11 cm/s; P = 0.0004) and cardiac index (3.0 +/- 0.7 vs. 2.5 +/- 0.5 L/min.m2; P = 0.002). A decrease that did not reach statistical significance was noted in flow velocity integral (18.9 +/- 2.7 vs. 16.5 +/- 3.4 cm; P = 0.07). Mean acceleration was decreased significantly (12.6 +/- 2.6 vs. 10.8 +/- 1.8 m/s.s; P = 0.01), but no significant changes in acceleration time (81 +/- 16 vs. 83 +/- 10 ms; P = 0.7) or ejection time (296 +/- 25 vs. 295 +/- 27 ms; P = 0.8) were observed. These results indicate that estrogen deprivation is associated with smaller stroke volume and flow acceleration and might suggest that hypoestrogenism has a direct effect on cardiovascular performance.

Inhibitory effect of a highly potent antagonist of LH releasing hormone (SB-75) on the pituitary gonadal axis in the intact and castrated rat

The biological potency of the new, highly potent antagonist [AC-D-Nal (2)1, D-Phe(4Cl)2, D-Pal(3)3, D-Cit6, D-Ala10] LH-RH (SB-75) on the pituitary-gonadal system of female castrated and intact ovulating rats was tested. Administration of a single dose (50-100 micrograms/kg BW) of the antagonist SB-75 inhibited effectively the elevated gonadotrophin levels for 48 h. Pituitary LH and FSH content was not affected by SB-75 treatment. When administered in the early afternoon of the proestrus to intact cycling rats, SB-75 blocked the preovulatory LH surge as well as the primary and secondary FSH surges. However, the secondary FSH surge was not affected by SB-75 treatment when administered on the evening of proestrus suggesting its independence from the LH-RH mechanism. A group of ovariectomized rats was chronically treated with D-Trp6-LH-RH after having been pretreated by administration of a single dose of the antagonist. The initial stimulatory release of LH and FSH initiated by injection of the LH-RH agonist was significantly reduced by pretreatment with the LH-RH antagonist. We conclude that the LH-RH antagonist SB-75 may be used effectively in the field of reproductive dysfunction and endocrinological oncology and may become an invaluable physiological probe in studying the hormonal dynamics of the reproductive endocrine axis.

Combined transvaginal tubal catheterization and adhesiolysis of filmy uterine synechiae performed with a newly developed device under the guidance of digital road mapping fluoroscopy

Transcervical fallopian tube catheterization is rapidly gaining favor as a minimally invasive diagnostic and therapeutic technique. On occasion, the presence of filmy adhesions not identified on HSG obstruct the passage of the cannula to the cornual angle. We describe the design and operative characteristics of a new transcervical adhesiolysis device that if used under the guidance of DRM mapping, can restore the shape of the uterine cavity and allow completion of the procedure during the same session.

Another look at co-treatment with growth hormone and human menopausal gonadotrophins in poor ovarian responders

The objective of this study was to evaluate whether a combined human growth hormone (HGH) and human menopausal gonadotrophin (HMG) treatment can improve ovulation induction in poor ovarian responders. Ten patients aged 28-43 years and requiring > 25 ampoules of HMG for ovulation were admitted to the study. Pituitary growth hormone reserve was evaluated by clonidine stimulation and insulin tolerance tests before commencement of treatment. The patients underwent one treatment cycle with D-tryptophan-6-luteinizing hormone-releasing hormone (D-Trp6-LHRH) and HMG and another cycle with D-Trp6-LHRH, HMG and HGH. Serum HGH, insulin-like growth factor (IGF)-I and oestradiol were measured throughout the two treatment cycles and follicular maturation was assessed by ultrasonographic studies. All patients tested showed no elevation of their serum HGH concentration during a clonidine test, but showed an adequate response during insulin tolerance tests. No significant difference was found in the number of HMG ampoules, duration of treatment, number of leading follicles, and serum oestradiol concentration between the two treatment cycles. Co-treatment with HGH and HMG did not improve ovarian performance in poor ovarian responders. No correlation was found between the results of HGH pituitary function tests and the ovarian response to gonadotrophins.

Digital road mapping image--a novel fluoroscopic real-time guide for selective transcervical catheterization in the treatment of proximal tubal obstruction

Ten infertile women 20 to 40 years of age, with a standard HSG diagnosis of unilateral proximal tubal obstruction, underwent a transvaginal catheterization and recanalization of the fallopian tubes. To set a fluoroscopic real-time guidance technique for improving the results of transvaginal catheterization and recanalization of the fallopian tubes and to increase its marginal safety, catheterization was performed under digital road mapping guidance. Transcervical catheterization resulted in an immediate patency of the obstructed tube in all 10 women. Three women conceived 2 to 3 months after the procedure. The improved catheterization technique enables good results in the diagnosis and treatment of proximal tubal obstructions.

Calcium homeostasis, bone metabolism and safety aspects during long-term treatment with a GnRH agonist

Thirty-five women with symptomatic fibroids were treated with monthly injections of 3.2 mg microcapsulated D-Trp-6-LHRH for 6 months. During treatment serum 17 beta-oestradiol levels decreased, falling to castration levels associated with a reduction in the volume of the fibroids. In 16 patients a complete calcium homeostasis and bone metabolism work-up was carried out during treatment and subsequently for a 6-month follow-up period. Bone mineral content (BMC) and Compton bone densitometry readings remained unchanged. There were significant increases in serum calcium phosphate and alkaline phosphatase concentrations. A slight although not significant increase was observed in osteocalcin and parathyroid hormone (PTH) serum levels. Serum 1,25(OH)2D3 values decreased significantly after 3 months of treatment. Urinary hydroxyproline/creatinine and calcium/creatinine ratios as well as 24-h urinary calcium values increased significantly during the treatment period but decreased rapidly to pretreatment values after 3 months in the follow-up period. The endocrine changes induced by the GnRH-agonist treatment were associated with reversible biochemical signs of increased bone turnover and no significant changes in bone mass, suggesting that the treatment can be administered safely for a period of 6 months in patients with oestrogen-dependent diseases.

Pregnancy outcome following early exposure to maternal luteinizing-hormone-releasing hormone agonist (buserelin)

A human pregnancy exposed to a luteinizing-hormone-releasing hormone agonist (buserelin) in its early stages is reported. The possible mechanisms leading to conception under this mode of treatment and its consequences are discussed.

Induction of ovulation with D-Trp6-LHRH combined with purified FSH in patients with polycystic ovarian disease

Seventeen patients with polycystic ovarian disease (PCOD) and evidence of mild or severe ovarian hyperstimulation syndrome (OHSS) during therapy with CC/hCG, FSH/hCG or hMG/hCG were treated with D-Trp6-LHRH until medical gonadectomy was attained. Under the suppressive therapy with the GnRH agonist (GnRHa) ovulation was induced with FSH/hCG. In 15 out of 17 patients, ovulatory cycles were obtained with this new modality of treatment. Seven patients conceived (3 viable pregnancies and 4 early abortions) after the 1st treatment cycle. Fourteen of the 17 patients demonstrated symptoms of mild OHSS which did not require hospitalization. Only 1 patient developed severe OHSS after the combined treatment. Our results suggest that therapy with GnRHa, especially in its delayed release formulation, is effective for the prevention of severe ovarian hyperstimulation in PCOD patients undergoing treatment with menotropins for the induction of ovulation.