Exposures to psycholeptics, psychoanaleptics, and cardiovascular drugs reported to the PIC erfurt during heat waves from 2003 to 2018.

Psycholeptics, psychoanaleptics, and cardiovascular drugs alter individual tolerance to extreme heat. To explore the influence of heat waves on their toxicity in acute overdose, we retrospectively analyzed all human exposures to psycholeptics and psychoanaleptics (PLAexp) as well as cardiovascular drugs (CVDexp) registered by the Poisons Information Center (PIC) Erfurt between June to September of the years 2003 to 2018 for frequency, age groups, sex, circumstances of exposure, and symptom severity. The results of the non-heat years (NHY) 2004-2005 and 2007-2014 (average air temperature June-September 16.2 °C) were compared to the results of the heat years (HY) 2003, 2006 and 2015-2018 (average air temperature June-September 17.5 °C). In total, 13,191 cases (HY 5,117; NHY 8,074) of PLAexp and 2,960 cases (HY 1,168; NHY 1,792) of CVDexp were registered. During HY, accidental PLAexp (11.2% versus 9.7%) and CVDexp (40.6% versus 36.8%) were more often seen. Severe symptoms were less frequent in PLAexp (4.4% versus 6.3%) and CVDexp (3.3% versus 4.9%). Although in HY, no higher rates of moderate or severe PLAexp and CVDexp were detected than in NHY, patients with these medications should be observed carefully during heat waves because of affected body's usual cooling mechanisms.

[Substance Abuse Poisoning Reported to the Poisons Information Centre Erfurt from 2002 to 2016]. / Substanzmissbrauch ­ Entwicklung des Vergiftungsgeschehens im Einzugsbereich des Giftnotrufes Erfurt 2002­2016.

AIM OF THE STUDY: Poisoning due to substance abuse has changed significantly during the last few years. Therefore, developments of substance abuse reported to the Poisons Information Centre Erfurt were investigated and compared to other circumstances of human exposures during the last 15 years. METHODS: Retrospective analysis of all cases of human exposures (intentional abuse, accidental and unknown circumstances, and suicide attempts) for the period 2002-2016 according to substance classes, reasons of exposures, symptom severity, age groups, and gender. RESULTS: Cases of substance abuse (n=7,237, 3.5% of all exposures) continuously increased from 250 (159 with one and 91 with multiple substances) in 2002 to 830 in 2016 (398 with one and 432 with multiple substances). Cases of exposure to metamphetamine strongly increased from 10 in 2003 to 100 in 2012 and dropped to 52 in 2016. Cases of exposure to new psychoactive substances (NPS) rose from 1 in 2008 to 130 in 2015 and fell to 90 in 2016. Substance abuse significantly (p<0.001) more often caused moderate (29.1%) and severe symptoms (5.8%) than suicide attempts (11.6%; 4.9%). NPS and their subgroup synthetic cannabinoids led significantly (p<0.001 and 0.025) more frequently to moderate and severe symptoms (46.9% and 43.6%; 7.9% and 6.0%) than cannabis exposure (19.7%; 2.1%). CONCLUSIONS: Clinical significance of substance abuse is shown by the fact that it resulted more often in moderate and severe symptoms than suicide attempts. Data of substance abuse from PICs could supplement those on clinical toxicology in official annual drug reports.

Highly potent and selective substrate analogue factor Xa inhibitors containing D-homophenylalanine analogues as P3 residue: part 2.

A series of highly potent substrate-analogue factor Xa inhibitors containing D-homophenylalanine analogues as the P3 residue has been identified by systematic optimization of a previously described inhibitor structure. An initial lead, benzylsulfonyl-D-hPhe-Gly-4-amidinobenzylamide (3), inhibits fXa with an inhibition constant of 6.0 nM. Most modifications of the P2 amino acid and P4 benzylsulfonyl group did not improve the affinity and selectivity of the compounds as fXa inhibitors. In contrast, further variation at the P3 position led to inhibitors with significantly enhanced potency and selectivity. Inhibitor 27, benzylsulfonyl-D-homo-2-pyridylalanyl(N-oxide)-Gly-4-amidinobenzylamide, inhibits fXa with a K(i) value of 0.32 nM. The inhibitor has strong anticoagulant activity in plasma and doubles the activated partial thromboplastin time and prothrombin time at concentrations of 280 nM and 170 nM, respectively. Compound 27 inhibits the prothrombinase complex with an IC(50) value of 5 nM and is approximately 50 times more potent than the reference inhibitor DX-9065a in this assay.

From selective substrate analogue factor Xa inhibitors to dual inhibitors of thrombin and factor Xa. Part 3.

Highly potent and selective substrate analogue factor Xa inhibitors were obtained by incorporation of non-basic or modestly basic P1 residues known from the development of thrombin inhibitors. The modification of the P2 and P3 amino acids strongly influenced the selectivity and provided potent dual factor Xa and thrombin inhibitors without affecting the fibrinolytic enzymes. Several inhibitors demonstrated excellent anticoagulant efficacy in standard clotting assays in human plasma.

Secondary amides of sulfonylated 3-amidinophenylalanine. New potent and selective inhibitors of matriptase.

Matriptase is an epithelium-derived type II transmembrane serine protease and has been implicated in the activation of substrates such as pro-HGF/SF and pro-uPA, which are likely involved in tumor progression and metastasis. Through screening, we have identified bis-basic secondary amides of sulfonylated 3-amidinophenylalanine as matriptase inhibitors. X-ray analyses of analogues 8 and 31 in complex with matriptase revealed that these inhibitors occupy, in addition to part of the previously described S4-binding site, the cleft formed by the molecular surface and the unique 60 loop of matriptase. Therefore, optimization of the inhibitors included the incorporation of appropriate sulfonyl substituents that could improve binding of these inhibitors into both characteristic matriptase subsites. The most potent derivatives inhibit matriptase highly selective with K(i) values below 5 nM. Molecular modeling revealed that their improved affinity results from interaction with the S4 site of matriptase. Analogues 8 and 59 were studied in an orthotopic xenograft mouse model of prostate cancer. Compared to control, both inhibitors reduced tumor growth, as well as tumor dissemination.

New substrate analogue inhibitors of factor Xa containing 4-amidinobenzylamide as P1 residue: part 1.

The trypsin-like serine protease factor Xa (fXa) is located at the convergence point of the intrinsic and extrinsic coagulation cascade, and therefore has emerged as an attractive target for the design of novel anticoagulants. During the development of substrate-analogue urokinase inhibitors we have found that the protection of the P3-dSer side chain leads to a scaffold of potent fXa inhibitors with the general structure R1-SO2-dSer(R2)-Gly-4-amidinobenzylamide. The first lead (3) with an N-terminal benzylsulfonyl group and dSer(tBu) as P3 residue inhibits human fXa with a Ki of 14 nM. A variety of derivatives with modified P4, P3, and P2 residues have been investigated in terms of inhibition of fXa and related proteases and for their anticoagulant potency and elimination behaviour. Most inhibitors were rapidly cleared from the circulation of rats. However, compound 48 (Ki= 3.5 nM), one of the most potent and selective inhibitors containing a dArg as P3 residue was relatively slowly eliminated (t1/2 approximately 1 h). Inhibitor 48 doubled clotting times in human plasma at 0.32 microM (aPTT) and 0.28 microM (PT), and is approximately 10-fold more potent than the reference fXa inhibitor DX-9065a in the inhibition of the prothrombinase complex. The structures of two inhibitors in complex with human fXa were solved by X-ray crystallography.

In vitro inhibition of matriptase prevents invasive growth of cell lines of prostate and colon carcinoma.

Matriptase, also known as membrane-type-serine-protease 1 (MT-SP 1), is a type II transmembrane serine protease involved in the activation of the precursor form of hepatocyte growth factor/scatter factor (pro-HGF/SF). Since HGF/SF is a well-known extracellular signal, which plays a key role in the control of invasive growth, we investigated the effects of matriptase inhibition in cell lines derived from colon (DLD-1) or prostate (PC-3) carcinomas. Biochemical analysis showed that matriptase was very efficient in the proteolytic conversion of the inactive HGF/SF precursor into HGF/SF. Inhibition of endogenous matriptase synthesis in DLD-1 or PC-3 cells by specific small interfering RNAs impaired the conversion of pro-HGF/SF into HGF/SF at the cell surface and inhibited cell scattering upon pro-HGF/SF stimulation. The same effect was observed after treatment of these cells with matriptase inhibitors of the 3-amidinophenylalanine-type, CJ-697 or CJ-730. Inhibition of matriptase significantly reduced invasion of the extracellular matrix as well. Interestingly, this reduction was observed even in the presence of pre-activated HGF/SF. It is concluded that matriptase plays a dual-role in the events unleashing the invasive phenotype, one 'upstream' from the HGF/SF signalling cascade and one 'downstream', most likely at the level of the plasminogen activation system. These data provide a proof of concept for the targeting of matriptase in the search for anti-invasive drugs.

Design of novel and selective inhibitors of urokinase-type plasminogen activator with improved pharmacokinetic properties for use as antimetastatic agents.

The serine protease urokinase-type plasminogen activator (uPA) interacts with a specific receptor (uPAR) on the surface of various cell types, including tumor cells, and plays a crucial role in pericellular proteolysis. High levels of uPA and uPAR often correlate with poor prognosis of cancer patients. Therefore, the specific inhibition of uPA with small molecule active-site inhibitors is one strategy to decrease the invasive and metastatic activity of tumor cells. We have developed a series of highly potent and selective uPA inhibitors with a C-terminal 4-amidinobenzylamide residue. Optimization was directed toward reducing the fast elimination from circulation that was observed with initial analogues. The x-ray structures of three inhibitor/uPA complexes have been solved and were used to improve the inhibition efficacy. One of the most potent and selective derivatives, benzylsulfonyl-D-Ser-Ser-4-amidinobenzylamide (inhibitor 26), inhibits uPA with a Ki of 20 nm. This inhibitor was used in a fibrosarcoma model in nude mice using lacZ-tagged human HT1080 cells, to prevent experimental lung metastasis formation. Compared with control (100%), an inhibitor dose of 2 x 1.5 mg/kg/day reduced the number of experimental metastases to 4.6 +/- 1%. Under these conditions inhibitor 26 also significantly prolonged survival. All mice from the control group died within 43 days after tumor cell inoculation, whereas 50% of mice from the inhibitor-treated group survived more than 117 days. This study demonstrates that the specific inhibition of uPA by these inhibitors may be a useful strategy for the treatment of cancer to prevent metastasis.