Pneumopericardium in the Neonate.

Pneumopericardium occurs when air accumulates in the pericardial sac surrounding the heart and is one of the rarest forms of air leaks in neonates. Because of various advances in neonatal care, including gentler modes of ventilation, surfactant replacement, and antenatal steroids, the incidence of pneumopericardium has decreased. Despite the decrease in incidence of pneumopericardium, most cases arise in premature infants with a history of respiratory distress and mechanical ventilation. Evidence has shown that the incidence is inversely related to birth weight and that pneumopericardium has high mortality and morbidity rates.

Ept7 influences estrogen action in the pituitary gland and body weight of rats.

Estrogens control many aspects of pituitary gland biology, including regulation of lactotroph homeostasis and synthesis and secretion of prolactin. In rat models, these actions are strain specific and heritable, and multiple quantitative trait loci (QTL) have been mapped that impact the responsiveness of the lactotroph to estrogens. One such QTL, Ept7, was mapped to RNO7 in female progeny generated in an intercross between BN rats, in which the lactotroph population is insensitive to estrogens, and ACI rats, which develop lactotroph hyperplasia/adenoma and associated hyperprolactinemia in response to estrogen treatment. The primary objective of this study was to confirm the existence of Ept7 and to quantify the impact of this QTL on responsiveness of the pituitary gland of female and male rats to 17ß-estradiol (E2) and diethylstilbestrol (DES), respectively. Secondary objectives were to determine if Ept7 influences the responsiveness of the male reproductive tract to DES and to identify other discernible phenotypes influenced by Ept7. To achieve these objectives, a congenic rat strain that harbors BN alleles across the Ept7 interval on the genetic background of the ACI strain was generated and characterized to define the effect of administered estrogens on the anterior pituitary gland and male reproductive tissues. Data presented herein indicate Ept7 exerts a marked effect on development of lactotroph hyperplasia in response to estrogen treatment, but does not affect atrophy of the male reproductive tissues in response to hormone treatment. Ept7 was also observed to exert gender specific effects on body weight in young adult rats.

Characterization of non-nitrocatechol pan and isoform specific catechol-O-methyltransferase inhibitors and substrates.

Reduced dopamine neurotransmission in the prefrontal cortex has been implicated as causal for the negative symptoms and cognitive deficit associated with schizophrenia; thus, a compound which selectively enhances dopamine neurotransmission in the prefrontal cortex may have therapeutic potential. Inhibition of catechol-O-methyltransferase (COMT, EC 2.1.1.6) offers a unique advantage, since this enzyme is the primary mechanism for the elimination of dopamine in cortical areas. Since membrane bound COMT (MB-COMT) is the predominant isoform in human brain, a high throughput screen (HTS) to identify novel MB-COMT specific inhibitors was completed. Subsequent optimization led to the identification of novel, non-nitrocatechol COMT inhibitors, some of which interact specifically with MB-COMT. Compounds were characterized for in vitro efficacy versus human and rat MB and soluble (S)-COMT. Select compounds were administered to male Wistar rats, and ex vivo COMT activity, compound levels in plasma and cerebrospinal fluid (CSF), and CSF dopamine metabolite levels were determined as measures of preclinical efficacy. Finally, novel non-nitrocatechol COMT inhibitors displayed less potent uncoupling of the mitochondrial membrane potential (MMP) compared to tolcapone as well as nonhepatotoxic entacapone, thus mitigating the risk of hepatotoxicity.

Triazine and pyrimidine based ROCK inhibitors with efficacy in spontaneous hypertensive rat model.

The profile of a series of triazine and pyrimidine based ROCK inhibitors is described. An initial binding mode was established based on a homology model and the proposed interactions are consistent with the observed SAR. Compounds from the series are potent in a cell migration assay and possess a favorable kinase selectivity. In vivo activity was demonstrated for compound 1A in a spontaneous hypertensive rat model.

Miniaturized, ultra-high throughput screening of tyrosine kinases using homogeneous, competitive fluorescence immunoassays.

Assay miniaturization and the implementation of high-density 1,536-microwell screening increase the speed and efficiency of screening and lead discovery. To serve this need, a platform of miniaturizable assay technologies has been assembled for specific biological targets. This platform will enable initiation and completion of uHTS screens in a straightforward and expeditious manner. Although faster primary screening does contribute to a reduction in timelines, the process of assay development can become a bottleneck. Assay technologies that do not require the use of target-specific reagents can reduce the time necessary for assay development. Assays that measure inhibition of tyrosine kinases can be configured in a competitive format where only the enzyme itself is specific to the assay. In this context, several technologies, including time-resolved fluorometry (also known as DELFIA), time-resolved fluorescence resonance energy transfer (also known as LANCE( trade mark )), fluorescence polarization, enzyme fragmentation complementation assay, and confocal laser scanning imaging, were examined. Quality parameters such as assay reproducibility, signal:background ratio, Z factor, and assay sensitivity were compared. Additionally, the relative merits of each of these technologies are assessed in terms of assay miniaturization, ease of development, ultimate screening capability, efficiency, and cost.

Evaluation of compound interference in immobilized metal ion affinity-based fluorescence polarization detection with a four million member compound collection.

IMAP is a non-separation-based, antibody-independent, FP assay that can be applied to many types of protein kinases and phosphatases. This technology is currently being used in many high-throughput screening campaigns throughout the industry. In this technology, a fluorescently labeled peptide substrate is phosphorylated and then captured on immobilized metal (M(III)) nanoparticles, an interaction that is enhanced at low pH (pH 5.5). The binding of the phosphorylated peptide to the nanoparticles is detected using FP. IMAP differs from other FP formats in that the polarization signal is antibody-independent and involves metal coordination complexes detected at low pH. Here, this technology is evaluated against a 4000000-member compound collection using a 1536-well assay design that is devoid of enzymes so that only interference of the compounds with the detection system is measured. Miniaturization of the assay to 1536-well plates is discussed. Compound interference due to inhibition of phosphopeptide binding to the M(III) nanoparticles is not observed. Additionally, it is concluded that the level of fluorescence compound interference is similar to typical FP formats for the majority of the compound collection.