Impaired motor coordination correlates with persistent multiple climbing fiber innervation in PKC gamma mutant mice

It is generally believed that a smooth execution of a compound movement, or motor coordination, requires learning of component movements as well as experience-based refinement of the motor program as a whole. PKC gamma mutant mice display impaired motor coordination but intact eyeblink conditioning, a form of component movement learning. Cerebellar long-term depression, a putative cellular mechanism for component motor learning, is also unimpaired. Thus, PKC gamma mutant mice are defective in refinement of the motor program. In the accompanying paper, we demonstrate that innervation of multiple climbing fibers onto Purkinje cells persists in adulthood in these mutant mice. We propose that this defective elimination of surplus climbing fibers underlies motor discoordination.     

Design and synthesis of novel conformationally restricted HIV protease inhibitors

A set of HIV protease inhibitors represented by compound 2 has previously been described. Structural and conformational analysis of this compound suggested that conformational restriction of the P1/P2 portion of the molecule could lead to a novel set of potent protease inhibitors. Thus, probe compounds 3-7 were designed, synthesized, and found to be potent inhibitors of HIV protease.     

Effects of conceptions of ability on anxiety, self-efficacy, and learning in training

Octreotide is labeled with fluorine-18 as a potential radiopharmaceutical for quantitative in vivo mapping of somatostatin receptors. [18F]-fluoroacylation is achieved with n.c.a. 2-[18F]fluoropropionic acid 4-nitrophenylester which is reacted with epsilon-Boc-Lys5-octreotide. After deprotection the desired N alpha-[18F]fluoropropionylated octreotide ([18F]SDZ 223-228) is obtained. Final HPLC purification gives rise to radiochemical yields of 65 +/- 5% based on the fluoroacylation agent. Binding experiments using rat cortex membranes indicate an affinity for somatostatin receptors of pKi = 8.6 +/- 0.2. The biological activity of this SRIF analog is demonstrated by the inhibition of growth hormone release from cultured pituitary cells. The pIC50 in this test system is 8.75, indicating full biological activity. Biodistribution studies with NMRI mice show predominantly renal excretion, rapid blood clearance and only negligible bone activity, i.e. formation of free fluoride.     

Identification and cloning of the membrane-associated serine protease, hepsin, from mouse preimplantation embryos

Previous studies have suggested the existence of a membrane-associated serine protease expressed by mammalian preimplantation embryos. In this study, we have identified hepsin, a type II transmembrane serine protease, in early mouse blastocysts. Mouse hepsin was highly homologous to the previously identified human and rat cDNAs. Two isoforms, differing in their cytoplasmic domains, were detected. The tissue distribution of mouse hepsin was similar to that seen in humans, with prominent expression in liver and kidney. In mouse embryos, hepsin expression was observed in the two-cell stage, reached a maximal level at the early blastocyst stage, and decreased subsequent to blastocyst hatching. Expression of a soluble form of hepsin revealed its ability to autoactivate in a concentration-dependent manner. Catalytically inactive soluble hepsin was unable to autoactivate. These results suggest that hepsin may be the first serine protease expressed during mammalian development, making its ability to autoactivate critical to its function.     

p53 nuclear protein expression is an independent prognostic marker in clinically localized prostate cancer patients undergoing radical prostatectomy

Immunohistochemical (IHC) staining for p53 protein nuclear expression was evaluated in archival paraffin-embedded radical prostatectomy specimens from 139 patients with clinically localized prostate cancer followed up from 1 to 8 (mean, 4) years. Elevated nuclear p53 protein expression was detected in 85 (61%) of 139 patients, being heterogeneous and focal in the majority of specimens. Only four specimens displayed homogeneous nuclear accumulation of p53 protein. Disease progression, most commonly prostate-specific antigen elevation, was noted in 46 (33%) patients, with 39 (85%) having positive p53 protein IHC stains. Conversely, 93 (67%) of 139 have not recurred, with 46 (49%) having positive p53. Of all 54 p53-negative patients, 47 (87%) have had no disease recurrence. An increased p53 protein IHC stain was associated with a higher pathological stage (T1 and T2, 51% versus >/=T3, 69%) and Gleason score 2-4, 17%; 5-7, 72%; and 8-10, 87.5%). Despite these associations, p53 IHC staining was an independent predictor of disease-free survival in a multivariate analysis of p53, age, race, stage, and grade. This study revealed that a majority of clinically localized prostate cancers heterogeneously express elevated nuclear levels of p53 protein in at least a subset of malignant cells, and that this expression is an independent predictor of disease progression in prostate cancer patients after radical prostatectomy.     

Restriction endonuclease mapping and molecular cloning of the human herpesvirus 6 variant B strain Z29 genome

Human herpesvirus 6(HHV-6) variants A and B differ in cell tropism, reactivity with monoclonal antibodies, restriction endonuclease profiles, and epidemiology. Nonetheless, comparative nucleotide and amino acid sequences from several genes indicate that the viruses are very highly conserved genetically, The B variant is the major etiologic agent of exanthem subitum and is frequently isolated from children with febrile illness; no disease has been etiologically associated with HHV-6A. One HHV-6A strain has been cloned and sequenced, but similar information and reagents are not available for HHV-6B. We report here the determination of maps of the restriction endonuclease cleavage sites for BamHI, C1aI, HindIII, KpnI, and Sa1I, and the cloning in plasmids and bacteriophages of fragments representing over 95% of the HHV-6B strain Z29 [HHV-6B(Z29)] genome. Hybridization experiments and orientation of several blocks of nucleotide sequence information onto the genomic map indicate that HHV-6A and HHV-6B genomes are colinear.     

Gastrointestinal autonomic nerve tumor: further observations regarding an ultrastructural and immunohistochemical analysis of six cases

Gastrointestinal autonomic nerve tumor (GANT) is a specialized form of stromal neoplasm whose ultrastructural features support a myenteric plexus derivation and provide the basis for its diagnosis. GANT actual frequency, relationship to skeinoid fibers, and CD34 expression status are some of the controversial aspects of this entity. Out of 14 gastrointestinal stromal tumors gathered during a 1-year period, six (42%) instances were diagnosed as GANT by electron microscopic study of at least five ultrathin sections per case. Additionally, GANTs were immunohistochemically investigated with a panel of nine antibodies including CD34. Ultrastructurally, every GANT case showed diagnostic findings and evidence of skeinoid fibers, whereas immunohistochemically all except one were CD34 positive. Immunoreactivity for neuron-specific enolase, synaptophysin, and vimentin was a common occurrence as well. In conclusion, GANT seems to be more frequent than hitherto recognized, skenoid fibers are a regular feature of GANT, and a positive CD34 immunoreaction does not discriminate between GANT and other non-smooth muscle, non-schwannian neoplasms.