Identification of Selective Imidazopyridine CSF1R Inhibitors.

Colony stimulating factor-1 receptor (CSF1R or c-FMS), a class III receptor tyrosine kinase expressed on members of the mononuclear phagocyte system (MPS), plays a key role in the proper functioning of macrophages, microglia, and related cells. Aberrant signaling through CSF1R has been associated with a variety of disease states, including cancer, inflammation, and neurodegeneration. In this Letter, we detail our efforts to develop novel CSF1R inhibitors.

Implications of promiscuous Pim-1 kinase fragment inhibitor hydrophobic interactions for fragment-based drug design.

We have studied the subtleties of fragment docking and binding using data generated in a Pim-1 kinase inhibitor program. Crystallographic and docking data analyses have been undertaken using inhibitor complexes derived from an in-house surface plasmon resonance (SPR) fragment screen, a virtual needle screen, and a de novo designed fragment inhibitor hybrid. These investigations highlight that fragments that do not fill their binding pocket can exhibit promiscuous hydrophobic interactions due to the lack of steric constraints imposed on them by the boundaries of said pocket.

The discovery of novel benzofuran-2-carboxylic acids as potent Pim-1 inhibitors.

Novel benzofuran-2-carboxylic acids, exemplified by 29, 38 and 39, have been discovered as potent Pim-1 inhibitors using fragment based screening followed by X-ray structure guided medicinal chemistry optimization. The compounds demonstrate potent inhibition against Pim-1 and Pim-2 in enzyme assays. Compound 29 has been tested in the Ambit 442 kinase panel and demonstrates good selectivity for the Pim kinase family.

Discovery of novel sphingosine kinase-1 inhibitors. Part 2.

Building on our initial work, we have identified additional novel inhibitors of sphingosine kinase-1 (SK1). These new analogs address the shortcomings found in our previously reported compounds. Inhibitors 51 and 54 demonstrated oral bioavailability in a rat PK study.

Discovery of novel sphingosine kinase 1 inhibitors.

Sphingosine kinase 1 (SK1) is an important enzyme that regulates the balance between ceramide and sphingosine-1-phosphate (S1P). Potent and novel SK1 inhibitors (6ag, 9ab and 12aa) have been discovered through a series of modifications of sphingosine (1), the substrate of this enzyme.

Specific metabolic properties of rat oculorotatory extraocular muscles can be linked to their low force requirements.

Purpose: To gain insight into the metabolic pathways of oculorotatory extraocular muscle (EOM) fiber types at the cellular level to explain their high fatigue resistance, rapid contraction, and low force output.

Methods: In consecutive sections of adult rat EOMs, the cross-sectional area (CSA) was calculated, and the activities of succinate-dehydrogenase (SDH) and alpha-glycerophosphate dehydrogenase (GPDH) were measured by quantitative histochemistry of different fiber types classified by the myofibrillar adenosine triphosphatase (mATPase) staining pattern.

Results: In the orbital regions, type 1 (fast) fibers were present, showing small CSA, medium SDH, and low GPDH activity.

Determination of slow-tonic MyHC immunoreactivity is an important step in the evaluation of muscle spindles in porcine extraocular muscles.

We have tested our hypothesis suggesting (i) that for the reliable determination and counting of muscle spindles (Msp) at the light microscopy level in extraocular muscles (EOM), analysis of the spindle specific myosin heavy chain (MyHC) immunoreactivity of intrafusal fibers, especially after staining with anti-slow-tonic MyHC antibodies, is the most convenient tool, (ii) that the number of Msp determined by the slow-tonic MyHC immunoreactivity of intrafusal fibers in EOM is much lower than that based on histological examination and (iii) that the previously reported numbers of Msp based on histological examination of EOM could be overestimated. In order to determine the number and distribution of Msp and to analyze the MyHC isoform immunoreactivity of intrafusal fibers in porcine EOM, paraffin sections of three 9-month-old pig medial (MR) and lateral rectus (LR), levator palpebrae (LP) and retractor bulbi (RB) muscles were stained histologically or using specific monoclonal antibodies (mAbs) against MyHC isoforms. Msp in recti and LP muscles studied by immunocytochemistry contained nuclear bag (NB) fiber(s) reacting with mAbs against slow-tonic, slow-twitch, alpha-cardiac and neonatal MyHCs, but not with the mAb against fast-twitch MyHC, which, on the contrary, stained nuclear chain (NC) fibers.

Fibre-related nitric oxide synthase (NOS) in Duchenne muscular dystrophy.

Nitric oxide (NO) mediates fundamental physiological actions on skeletal muscle. The loss of NO synthase (NOS) from the sarcolemma was assumed to be associated with development of Duchenne muscular dystrophy (DMD). We have, however, recently reported that, in contrast to the commonly accepted view, NOS expression in DMD myofibres is up-regulated.

Effects of caffeine at different temperatures on contractile properties of slow-twitch and fast-twitch rat muscles.

The slow-twitch soleus muscle (SOL) exhibits decreased twitch tension (cold depression) in response to a decreased temperature, whereas the fast-twitch extensor digitorum longus (EDL) muscle shows enhanced twitch tension (cold potentiation). On the other hand, the slow-twitch SOL muscle is more sensitive to twitch potentiation and contractures evoked by caffeine than the fast-twitch EDL muscle. In order to reveal the effects of these counteracting conditions (temperature and caffeine), we have studied the combined effects of temperature changes on the potentiation effects of caffeine in modulating muscle contractions and contractures in both muscles.

The effect of a unilateral muscle transplantation on the muscle fiber type and the MyHC isoform content in unoperated hind limb slow and fast muscles of the inbred Lewis rats.

To reveal the effect of foreign innervation and altered thyroid status on fiber type composition and the myosin heavy chain (MyHC) isoform expression in the rat slow soleus (SOL) and fast extensor digitorum longus (EDL) muscles, a method of heterochronous isotransplantation was developed. In this experimental procedure, the SOL or EDL muscles of young inbred Lewis rats are grafted either into the host EDL or SOL muscles of adult rats of the same strain with normal or experimentally altered thyroid status. To estimate the extent of fiber type transitions in the transplanted muscles, the SOL and EDL muscle from the unoperated leg and unoperated muscles from the operated leg could be legitimately used as controls, but only when the experimental procedure itself does not affect these muscles.

Effects of artificial obstruction on the function of the upper urinary tract of Guinea pigs, rats and pigs.

Purpose: Four different experiments in animals were performed to evaluate the influence of pyelo-ureteral surgery on the function of the upper urinary tract.

Methods: Experiment I: In 17 female guinea pigs pyelo-ureteral anastomosis was performed microsurgically. Three months later, the ureteral peristalsis was investigated by measuring the intraureteral pressure and the in vitro activity of the renal pelvic and ureteric wall was analysed.

Differentiation of rat skeletal muscle fibres during development and ageing.

The purpose of the present study was to determine at which point in the period from embryonic day 21 up to postnatal day (PD) 75, the different fibre types and subtypes are detectable in rat extensor digitorum longus, soleus and gastrocnemius muscles using immunohistochemical, enzyme histochemical and cytophotometrical methods. Moreover, fibre type-specific changes in metabolic profile and changes in fibre type population during postnatal development were analysed. Before birth, no clear differentiation of fibre types was found.

Contractile properties, fiber types, and myosin isoforms in fast and slow muscles of hyperactive Japanese waltzing mice.

This study focuses on the effects of neuromuscular hyperactivity on the contractile properties, fiber type composition, and myosin heavy chain (MHC) isoform expression of fast-twitch extensor digitorum longus (EDL) and slow-twitch soleus (SOL) muscles in Japanese waltzing mice (JWM) of the C57BL/6J-v2J strain. The same properties were studied in the homologous muscle of control CBA/J mice (CM). In comparison to CM, the JWM exhibited (i) longer activity periods, prolonged bouts of running and a higher food intake, (ii) slower twitch and tetanic contractions of both EDL and SOL muscles, decreased cold and post-tetanic potentiation of the EDL, as well as increased cold and post-tetanic depressions of the SOL.

Spectral enhancement of leucocrystal violet treated footwear impression evidence in blood.

The results presented demonstrate the capacity for spectral enhancement to substantially improve the forensic examination of footwear impressions in blood treated with leucocrystal violet (LCV). The UV-Vis absorption spectra were generated of (i) an aqueous solution of leucocrystal violet, (ii) leucocrystal violet in 3% H(2)O(2), (iii) LCV working solution and (iv) whole blood added to LCV working solution. The resultant fluorescence emission spectra were subsequently generated (lambda(ex)=630nm, lambda(em)=661-900nm).

Actions of lyotropic anions on the mechanical properties of fast and slow twitch rat muscles at different temperatures.

The effects of lyotropic (swelling) anions (Cl(-), Br(-), NO(3)(-) and I(-)) on contractile properties of fast-twitch extensor digitorum longus (EDL) and slow-twitch soleus (SOL) muscles were investigated in vitro at 20 degrees C and 35 degrees C. Isolated muscles bathed in anionic Tyrode solution were stimulated directly and isometric single twitches and fused tetanic contractions were recorded. In a Cl(-)Tyrode solution a decrease of the bathing temperature led to a cold potentiation of the twitch tension (P(t)) in EDL muscles, however, to a cold depression in SOL muscles, in both muscles combined with a prolongation of contraction (CT) and half relaxation (HRT) times.

Nitric oxide synthase II in rat skeletal muscles.

Constitutive expression of nitric oxide synthase (NOS) II was found in rat hindlimb muscles by immunohistochemistry and western blotting during development from embryonic day 21 to the adult stage of 75 days. The immunohistochemical NOS II expression pattern was related to the physiological metabolic fibre types SO (slow-oxidative), FOG I, II (fast-oxidative glycolytic; I more glycolytic, II more oxidative) and FG (fast-glycolytic) and to the myosin-based fibre types I and IIA, IIB (IIX not separated) identified in serial sections by enzyme histochemistry and immunohistochemistry. In adult muscles only the small population of FOG II fibres, which is a part of both IIA and IIB fibre population, showed NOS II immunoreactivity.

[Neuromuscular reinnervation of mimetic muscles. A histomorphologic study of the zygomatic muscle of the rabbit].

To evaluate occurrences of reinnervation and degeneration, the portio auricularis of the zygomatic muscle was reinnervated (either primary or secondary reinnervation) with an interval of 6 weeks, using a neuromuscular transplant of the sternohyoid muscle, which was left at the ansa hypoglossi. Histological examination was performed 6 and 12 weeks later. Enzymatic stains for myofibrillar ATPase were used for differentiation of muscle fibre types.

Contraction parameters, myosin composition and metabolic enzymes of the skeletal muscles of the etruscan shrew Suncus etruscus and of the common European white-toothed shrew Crocidura russula (Insectivora: soricidae).

In the Etruscan shrew, the isometric twitch contraction times of extensor digitorum longus (EDL) and soleus muscles are shorter than in any other mammal, allowing these muscles to contract at outstandingly high contraction frequencies. This species has the highest mass-specific metabolic rate of all mammals and requires fast skeletal muscles not only for locomotion but also for effective heat production and for an extremely high ventilation rate. No differences could be detected in the fibre type pattern, the myosin heavy and light chain composition, or in the activity of the metabolic enzymes lactate dehydrogenase and citrate synthase of the two limb muscles, the EDL and the soleus, which in larger mammalian species exhibit distinct differences in contractile proteins and metabolic enzymes.

Effects on skeletal muscle fibres of diabetes and Ginkgo biloba extract treatment.

Combined cytophotometric and morphometric analysis of muscle fibre properties and myosin heavy chain electrophoresis were performed on extensor digitorum longus and soleus muscles from healthy rats and rats with streptozotocin-induced diabetes. Moreover, the protective effect of Ginkgo biloba extract, a potent oxygen radical scavenger, on diabetic muscles was investigated. Changes in fibre type-related enzyme activities, fibre type distribution, fibre cross areas and myosin isoforms were found.

Cardiomyoplasty - improvement of muscle fibre type transformation by an anabolic steroid (metenolone).

Dynamic cardiomyoplasty, a method to support ventricular function by the chronically stimulated latissimus dorsi muscle wrapped around the heart is accompanied by a loss of mass and force of the transplanted muscle. These effects and the fast-to-slow transformation of the muscle could be possibly influenced by the additional administration of anabolic steroids. In this study, the left latissimus dorsi muscles of 12 sheep were electrically conditioned (group A).

Anabolic steroids (metenolone) improve muscle performance and hemodynamic characteristics in cardiomyoplasty.

The loss of force and mass in the conditioned latissimus dorsi muscle are principal reasons for the poor improvement in hemodynamic functioning attained by cardiomyoplasty. Using 24 sheep, we investigated the effect of anabolic steroids on the hemodynamic, histologic, and myophysiologic characteristics in the setting of cardiomyoplasty. In 12 of the animals (group A), the latissimus dorsi muscles were electrically conditioned with an Itrel pulse generator; in the remaining 12 animals (group B), the electrical conditioning was combined with the administration of an anabolic hormone (metenolone; 100 mg/week).

The force-velocity relation of the rabbit inferior oblique muscle; influence of temperature.

The contractile properties of the rabbit inferior oblique muscle (IO) were studied in vitro with direct stimulation at temperatures between 20 and 35 degrees C. Isovelocity releases were used to determine the force/velocity relation. Cooling the muscle from 35 degrees C to 20 degrees C increased contraction and half-relaxation times of single twitches with a temperature coefficient (Q10) of 0.

Effect of an anabolic steroid (Metenolon) on contractile performance of the chronically stimulated latissimus dorsi in sheep.

In 12 sheep the left latissimus dorsi muscles (LD) were conditioned by chronic electrostimulation with a pulse generator (Itrel, Medtronic). Six animals (group B) received a weekly intramuscular injection of an anabolic steroid (Metenolon). After 14 weeks the contraction parameters of the left LDs (group A and B) and right LDs (control group) were investigated.

Electrophoretic analysis of myosin heavy chain isoform patterns in extraocular muscles of the rat.

Six oculorotatory muscles and the levator palpebrae muscle of the rat were analysed by SDS-PAGE for their myosin heavy chain (MHC) isoform patterns. Oculorotatory muscles display a marked predominance of fast MHC isoforms. They contain, in addition to the slow (MHCI) and fast (MHCIIb, MHCIId, MHCIIa) skeletal MHCs, the neonatal MHCneo and the extraocular MHCeom.