Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 33
Filter
1.
Clin Ther ; 43(2): 279-286, 2021 02.
Article in English | MEDLINE | ID: mdl-33246660

ABSTRACT

The placenta is vital to the health and development of the fetus, serving to deliver oxygen and nutrients, facilitate the removal of waste products, and provide a barrier to pathogens and other harmful substances present in the maternal circulation. When these processes fail to operate normally, they can lead to complications of pregnancy such as preeclampsia or fetal growth restriction. The development of novel therapeutics for the mother, fetus, or placenta requires a mechanistic understanding of the development and functions of the placenta. For the obstetric clinician, being able to monitor the placenta throughout the pregnancy and to measure the impact of any treatment modality on the mother and the developing fetus are essential for providing the best possible care. The Eunice Kennedy Shriver National Institute of Child Health and Human Development at the National Institutes of Health has been a longtime supporter of research on the placenta. In 2014, the Human Placenta Project was initiated to help to drive an understanding of the biology of the human placenta and to facilitate the development of novel tools and approaches to allow for safe, noninvasive, real-time assessment of the placenta across pregnancy. Those efforts, along with others from around the globe, are showing promise. Although not yet ready for clinical application, these advances are moving the field forward and are certain to have a tremendous impact on the development and assessment of therapeutics designed for treating conditions of pregnancy.


Subject(s)
Placenta/physiology , Pregnancy/physiology , Biomedical Research , Female , Fetal Growth Retardation , Fetus , Humans , Placenta/physiopathology , Pre-Eclampsia/physiopathology , Pregnancy Complications/therapy
2.
Curr Opin Ophthalmol ; 29(6): 477-484, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30281029

ABSTRACT

PURPOSE OF REVIEW: Myasthenia gravis is an autoimmune disease that commonly affects the palpebral and extraocular muscles. Ocular myasthenia gravis (OMG) is a variant of the disease that is confined to the ocular muscles but frequently becomes generalized over time. The diagnosis of OMG is often challenging but both clinical and laboratory findings are helpful in confirming the clinical suspicion. This review provides an update on the diagnostic approach and therapeutic options for OMG. RECENT FINDINGS: Antimuscle-specific tyrosine kinase and LDL-related receptor-related protein 4 are newly available serologic testing for myasthenia gravis that can help in increasing the diagnostic sensitivity of OMG. They should be included to the diagnostic algorithm of OMG in appropriate clinical situations. SUMMARY: OMG remains a primarily clinical diagnosis, but recent advances in laboratory testing can improve the diagnostic accuracy and should be used in appropriate clinical settings. The mainstay of treatment for OMG has not significantly changed over the past years, but the increasing availability of steroid-sparing agents improved the disease control while minimizing steroid-induced complications.


Subject(s)
Myasthenia Gravis/diagnosis , Myasthenia Gravis/drug therapy , Diagnostic Techniques, Ophthalmological , Glucocorticoids/therapeutic use , Humans , Immunosuppressive Agents/therapeutic use , Oculomotor Muscles/pathology
3.
Mon Not R Astron Soc ; 459(3): 3040-3058, 2016 Jul 01.
Article in English | MEDLINE | ID: mdl-27279784

ABSTRACT

We model the luminosity-dependent projected and redshift-space two-point correlation functions (2PCFs) of the Sloan Digital Sky Survey (SDSS) Data Release 7 Main galaxy sample, using the halo occupation distribution (HOD) model and the subhalo abundance matching (SHAM) model and its extension. All the models are built on the same high-resolution N-body simulations. We find that the HOD model generally provides the best performance in reproducing the clustering measurements in both projected and redshift spaces. The SHAM model with the same halo-galaxy relation for central and satellite galaxies (or distinct haloes and subhaloes), when including scatters, has a best-fitting χ2/dof around 2-3. We therefore extend the SHAM model to the subhalo clustering and abundance matching (SCAM) by allowing the central and satellite galaxies to have different galaxy-halo relations. We infer the corresponding halo/subhalo parameters by jointly fitting the galaxy 2PCFs and abundances and consider subhaloes selected based on three properties, the mass Macc at the time of accretion, the maximum circular velocity Vacc at the time of accretion, and the peak maximum circular velocity Vpeak over the history of the subhaloes. The three subhalo models work well for luminous galaxy samples (with luminosity above L*). For low-luminosity samples, the Vacc model stands out in reproducing the data, with the Vpeak model slightly worse, while the Macc model fails to fit the data. We discuss the implications of the modelling results.

4.
Proc Natl Acad Sci U S A ; 112(40): 12249-55, 2015 Oct 06.
Article in English | MEDLINE | ID: mdl-25646464

ABSTRACT

The cold dark matter (CDM) cosmological model has been remarkably successful in explaining cosmic structure over an enormous span of redshift, but it has faced persistent challenges from observations that probe the innermost regions of dark matter halos and the properties of the Milky Way's dwarf galaxy satellites. We review the current observational and theoretical status of these "small-scale controversies." Cosmological simulations that incorporate only gravity and collisionless CDM predict halos with abundant substructure and central densities that are too high to match constraints from galaxy dynamics. The solution could lie in baryonic physics: Recent numerical simulations and analytical models suggest that gravitational potential fluctuations tied to efficient supernova feedback can flatten the central cusps of halos in massive galaxies, and a combination of feedback and low star formation efficiency could explain why most of the dark matter subhalos orbiting the Milky Way do not host visible galaxies. However, it is not clear that this solution can work in the lowest mass galaxies, where discrepancies are observed. Alternatively, the small-scale conflicts could be evidence of more complex physics in the dark sector itself. For example, elastic scattering from strong dark matter self-interactions can alter predicted halo mass profiles, leading to good agreement with observations across a wide range of galaxy mass. Gravitational lensing and dynamical perturbations of tidal streams in the stellar halo provide evidence for an abundant population of low-mass subhalos in accord with CDM predictions. These observational approaches will get more powerful over the next few years.

5.
J Clin Neuromuscul Dis ; 14(1): 17-20, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22922577

ABSTRACT

Intravascular large B-cell lymphoma, also known as angiotrophic large cell lymphoma, is a rare disorder where neoplastic lymphoid cells proliferate within the walls of small- to medium-sized blood vessels. Peripheral neuropathy and other neurological manifestations, including stroke and dementia, are common, but cases of isolated multiple mononeuropathies in the absence of systemic symptoms are distinctly rare. We present an unusual case of biopsy-proved angiotrophic large cell lymphoma presenting exclusively with multiple mononeuropathies.


Subject(s)
Lymphoma, Large B-Cell, Diffuse/complications , Mononeuropathies/complications , Mononeuropathies/diagnosis , Humans , Male , Middle Aged
6.
7.
Bioorg Med Chem Lett ; 20(22): 6524-32, 2010 Nov 15.
Article in English | MEDLINE | ID: mdl-20933410

ABSTRACT

We report an SAR study of MC4R analogs containing spiroindane heterocyclic privileged structures. Compound 26 with N-Me-1,2,4-triazole moiety possesses exceptional potency at MC4R and potent anti-obesity efficacy in a mouse model. However, the efficacy is not completely mediated through MC4R. Additional SAR studies led to the discovery of compound 32, which is more potent at MC4R. Compound 32 demonstrates MC4R mediated anti-obesity efficacy in rodent models.


Subject(s)
Obesity/drug therapy , Receptor, Melanocortin, Type 4/agonists , Triazoles/pharmacology , Animals , Chromatography, High Pressure Liquid , Disease Models, Animal , Mice , Mice, Knockout , Molecular Structure , Rats , Receptor, Melanocortin, Type 4/genetics , Structure-Activity Relationship , Triazoles/chemistry , Triazoles/therapeutic use
10.
Bioorg Med Chem Lett ; 20(15): 4399-405, 2010 Aug 01.
Article in English | MEDLINE | ID: mdl-20598882

ABSTRACT

We report a series of potent and selective MC4R agonists based on spiroindane amide privileged structures for potential treatments of obesity. Among the synthetic methods used, Method C allows rapid synthesis of the analogs. The series of compounds can afford high potency on MC4R as well as good rodent pharmacokinetic profiles. Compound 1r (MK-0489) demonstrates MC4R mediated reduction of food intake and body weight in mouse models. Compound 1r is efficacious in 14-day diet-induced obese (DIO) rat models.


Subject(s)
Amides/chemistry , Anti-Obesity Agents/chemistry , Obesity/drug therapy , Pyrrolidines/chemistry , Receptor, Melanocortin, Type 4/agonists , Spiro Compounds/chemistry , Amides/pharmacokinetics , Amides/therapeutic use , Animals , Anti-Obesity Agents/pharmacokinetics , Anti-Obesity Agents/therapeutic use , Body Weight/drug effects , Humans , Mice , Mice, Knockout , Pyrrolidines/pharmacokinetics , Pyrrolidines/therapeutic use , Rats , Rats, Sprague-Dawley , Receptor, Melanocortin, Type 4/metabolism , Spiro Compounds/pharmacokinetics , Spiro Compounds/therapeutic use , Structure-Activity Relationship
11.
Bioorg Med Chem Lett ; 20(7): 2106-10, 2010 Apr 01.
Article in English | MEDLINE | ID: mdl-20207541

ABSTRACT

We report the design, synthesis and properties of spiroindane based compound 1, a potent, selective, orally bioavailable, non-peptide melanocortin subtype-4 receptor agonist. Compound 1 shows excellent erectogenic activity in the rodent models.


Subject(s)
Erectile Dysfunction/drug therapy , Indans/chemistry , Indans/therapeutic use , Receptor, Melanocortin, Type 4/agonists , Receptor, Melanocortin, Type 4/metabolism , Spiro Compounds/chemistry , Spiro Compounds/therapeutic use , Animals , CHO Cells , Cricetinae , Cricetulus , Dogs , Haplorhini , Humans , Indans/pharmacokinetics , Indans/pharmacology , Male , Mice , Molecular Structure , Protein Binding , Rats , Spiro Compounds/pharmacokinetics , Spiro Compounds/pharmacology , Structure-Activity Relationship
12.
Ann Neurol ; 65(4): 386-93, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19399887

ABSTRACT

OBJECTIVE: Randomized, blinded trial of intramuscular gene transfer using plasmid vascular endothelial growth factor (VEGF) to treat diabetic polyneuropathy. METHODS: Diabetic patients with polyneuropathy were randomized to receive a VEGF-to-placebo ratio of 3:1. Three sets of injections were given at eight standardized sites adjacent to the sciatic, peroneal, and tibial nerves of one leg. Primary outcomes were change in symptom score at 6 months and a prespecified overall clinical and electrophysiological improvement score. Secondary outcomes were differences in symptoms, examination scores, visual analog pain scale, nerve conduction, and quantitative sensory testing. RESULTS: Thirty-nine patients received plasmid VEGF and 11 received placebo. Mean symptom score improved in both legs at 6 months, favoring VEGF over placebo (-1.2 +/- 0.5 vs -0.9 +/- 0.5; p < 0.01 after adjustment for change in the untreated leg) and compared with the untreated leg (-0.7 +/- 0.5; p = 0.02). The region of sensory loss and visual analog pain scale improved in the treated group (-1.5 vs -0.5; p = 0.01). Twelve of 39 VEGF versus 2 of 11 placebo patients met criterion for overall improvement. Other measures including nerve conduction potentials did not improve. There were 84 adverse events in VEGF patients, and 22 were serious; there were 51 events in placebo patients, and 2 were serious. INTERPRETATION: Intramuscular plasmid VEGF gene transfer improved diabetic neuropathic symptoms, meeting primary end-point criteria for efficacy but not affecting most secondary measures. Treatment was associated with more serious adverse events that did not reach statistical significance. These results are not conclusive but may justify further clinical study.


Subject(s)
Diabetic Neuropathies/therapy , Gene Transfer Techniques , Genetic Therapy/methods , Vascular Endothelial Growth Factor A/genetics , Vascular Endothelial Growth Factor A/therapeutic use , Aged , Cohort Studies , Diabetic Neuropathies/metabolism , Double-Blind Method , Female , Humans , Male , Middle Aged , Neural Conduction/genetics , Pain Measurement , Peripheral Nerves/physiopathology , Severity of Illness Index , Treatment Outcome
15.
Mol Ther ; 15(1): 69-75, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17164777

ABSTRACT

Toxic neuropathy represents an important clinical problem in the use of the chemotherapeutic substances Taxol and thalidomide. Sensory neuropathy has a high incidence, lacks an effective treatment and is the dose-limiting factor for these drugs. The pathogenic basis of these neuropathies is unknown. We investigated the hypothesis that the experimental toxic neuropathies from Taxol and thalidomide results from destruction of vasa nervorum and can be reversed by the administration of an angiogenic cytokine. In animal models of Taxol- and thalidomide-induced neuropathy, nerve blood flow has been attenuated and the number of vasa nervorum has been reduced. Intramuscular gene transfer of naked plasmid DNA encoding VEGF-1 administered in parallel with Taxol injections completely inhibited deterioration of nerve function and diminution of the peripheral nerve vasculature. Gene therapy in animals with established Taxol- or thalidomide-induced neuropathies resulted in recovery of vascularity and improved nerve electrophysiology. These findings implicate microvascular damage as the basis for toxic neuropathy and suggest that angiogenic growth factors may constitute a novel treatment for this disorder.


Subject(s)
Neovascularization, Pathologic/drug therapy , Paclitaxel/pharmacology , Peripheral Nervous System Diseases/chemically induced , Thalidomide/pharmacology , Vasa Nervorum/drug effects , Vasa Nervorum/injuries , Vascular Endothelial Growth Factor A/pharmacology , Animals , Apoptosis/drug effects , Cells, Cultured , Drug Therapy, Combination , Electrophysiology , Endothelial Cells/drug effects , Endothelial Cells/enzymology , Humans , Injections, Intramuscular , Lectins/pharmacology , MAP Kinase Signaling System/drug effects , Male , Mitogen-Activated Protein Kinases/metabolism , Peripheral Nervous System Diseases/pathology , Phosphatidylinositol 3-Kinases/metabolism , Plasmids/genetics , Proto-Oncogene Proteins c-akt/metabolism , Rats , Rats, Sprague-Dawley , Renal Circulation
16.
Clin Neurophysiol ; 117(2): 405-13, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16403673

ABSTRACT

OBJECTIVE: This study evaluated validity and reliability of automated median and ulnar sensory nerve conduction study (NCS) measurements by the NC-stat. METHODS: Median and ulnar distal sensory latencies (DSL) and amplitudes (SNAP) were measured in sixty subjects with the NC-stat and by a neurologist (reference) using traditional instrumentation. The median-ulnar DSL differences (MUD) was calculated. Validity was quantified by the Pearson correlation. Reliability was evaluated by the intraclass correlation coefficient (ICC), Bland-Altman analysis, and inter-rater agreement of MUD abnormalities. RESULTS: As a result of differences in electrode placement, NC-stat and reference mean values had systematic differences. The correlation ranged from 0.70 (ulnar DSL) to 0.91 (median DSL). The ICC ranged from 0.69 (ulnar DSL) to 0.91 (median DSL). In Bland-Altman analysis of DSLs, NC-stat measurements had a bias of 0.56 ms (median) and 0.31 ms (ulnar) and precision of 0.31 and 0.30 ms. Inter-rater agreement for MUD abnormalities was 93.8% (raw) and 0.80 (Kappa). CONCLUSIONS: NC-stat validity and reliability metrics were similar to traditional NCS. Use of the NC-stat would require applicable reference ranges. SIGNIFICANCE: NC-stat median and ulnar NCS are valid and reliable. This device may be useful for increasing availability of NCS when clinically appropriate.


Subject(s)
Electric Stimulation/instrumentation , Electric Stimulation/methods , Median Nerve/physiopathology , Neural Conduction/physiology , Peripheral Nervous System Diseases/physiopathology , Ulnar Nerve/physiopathology , Action Potentials/physiology , Action Potentials/radiation effects , Adolescent , Adult , Aged , Electrodes , Electromyography/methods , Female , Humans , Male , Middle Aged , Reaction Time/physiology , Reaction Time/radiation effects , Reference Values , Reproducibility of Results , Statistics as Topic
17.
18.
Biochemistry ; 44(34): 11329-41, 2005 Aug 30.
Article in English | MEDLINE | ID: mdl-16114870

ABSTRACT

Specific interactions of human melanocortin-4 receptor (hMC4R) with its nonpeptide and peptide agonists were studied using alanine-scanning mutagenesis. The binding affinities and potencies of two synthetic, small-molecule agonists (THIQ, MB243) were strongly affected by substitutions in transmembrane alpha-helices (TM) 2, 3, 6, and 7 (residues Glu(100), Asp(122), Asp(126), Phe(261), His(264), Leu(265), and Leu(288)). In addition, a I129A mutation primarily affected the binding and potency of THIQ, while F262A, W258A, Y268A mutations impaired interactions with MB243. By contrast, binding affinity and potency of the linear peptide agonist NDP-MSH were substantially reduced only in D126A and H264A mutants. Three-dimensional models of receptor-ligand complexes with their agonists were generated by distance-geometry using the experimental, homology-based, and other structural constraints, including interhelical H-bonds and two disulfide bridges (Cys(40)-Cys(279), Cys(271)-Cys(277)) of hMC4R. In the models, all pharmacophore elements of small-molecule agonists are spatially overlapped with the corresponding key residues (His(6), d-Phe(7), Arg(8), and Trp(9)) of the linear peptide: their charged amine groups interact with acidic residues from TM2 and TM3, similar to His(6) and Arg(6) of NDP-MSH; their substituted piperidines mimic Trp(9) of the peptide and interact with TM5 and TM6, while the d-Phe aromatic rings of all three agonists contact with Leu(133), Trp(258), and Phe(261) residues.


Subject(s)
Peptides/pharmacology , Receptor, Melanocortin, Type 4/metabolism , Amino Acid Sequence , Binding Sites , Cyclic AMP/pharmacology , Humans , Models, Molecular , Molecular Sequence Data , Mutagenesis, Site-Directed , Piperazines/pharmacology , Piperidines/pharmacology , Protein Structure, Secondary , Receptor, Melanocortin, Type 4/agonists , Receptor, Melanocortin, Type 4/chemistry , Receptor, Melanocortin, Type 4/drug effects , Recombinant Proteins/chemistry , Recombinant Proteins/drug effects , Recombinant Proteins/metabolism , Rhodopsin/chemistry , Sequence Alignment , Sequence Homology, Amino Acid , Transfection
19.
Science ; 309(5734): 564-5, 2005 Jul 22.
Article in English | MEDLINE | ID: mdl-16040694
SELECTION OF CITATIONS
SEARCH DETAIL
...