Preventing mediastinal shift after pneumonectomy does not abolish physiological compensation

To determine the role of mediastinal shift after pneumonectomy (PNX) on compensatory responses, we performed right PNX in adult dogs and replaced the resected lung with a custom-shaped inflatable silicone prosthesis. Prosthesis was inflated (Inf) to prevent mediastinal shift, or deflated (Def), allowing mediastinal shift to occur. Thoracic, lung air, and tissue volumes were measured by computerized tomography scan. Lung diffusing capacities for carbon monoxide (DL(CO)) and its components, membrane diffusing capacity for carbon monoxide (Dm(CO)) and capillary blood volume (Vc), were measured at rest and during exercise by a rebreathing technique. In the Inf group, lung air volume was significantly smaller than in Def group; however, the lung became elongated and expanded by 20% via caudal displacement of the left hemidiaphragm. Consequently, rib cage volume was similar, but total thoracic volume was higher in the Inf group. Extravascular septal tissue volume was not different between groups. At a given pulmonary blood flow, DL(CO) and Dm(CO) were significantly lower in the Inf group, but Vc was similar. In one dog, delayed mediastinal shift occurred 9 mo after PNX; both lung volume and DL(CO) progressively increased over the subsequent 3 mo. We conclude that preventing mediastinal shift after PNX impairs recruitment of diffusing capacity but does not abolish expansion of the remaining lung or the compensatory increase in extravascular septal tissue volume.

VIDAS enzyme-linked immunoflourescent assay for detection of Listeria in foods: collaborative study

The VIDAS LIS method and the traditional culture methods for detection of Listeria species in food were evaluated in a multilaboratory comparative study. The 6 foods tested were either naturally contaminated or inoculated with 3 different concentrations of Listeria. Results for each food and each contamination level with the VIDAS LIS method were as good as or better than those obtained with the traditional culture method. Of 1558 samples tested, 935 were positive: 839 by the VIDAS method and 809 by standard culture methods. Overall false negative rates were 10.3 and 13.5% for the VIDAS LIS and culture methods, respectively. The false positive rate for the VIDAS LIS assay was 1.4% based on 9 VIDAS LIS positive assays that did not confirm positive by isolation of Listeria. The agreement between the VIDAS LIS and culture methods for all samples tested was 86%.

Multiple calvarial defects in lmx1b mutant mice

The vertebrate cranial vault, or calvaria, forms during embryonic development from cranial mesenchyme of multiple embryonic origins. Inductive interactions are thought to specify the number and location of the calvarial bones, including interactions between the neuroepithelium and cranial mesenchyme. An important feature of calvarial development is the local inhibition of osteogenic potential which occurs between specific bones and results in the formation of the cranial sutures. These sutures allow for postnatal growth of the skull to accommodate postnatal increase in brain size. The molecular genetic mechanisms responsible for the patterning of individual calvarial bones and for the specification of the number and location of sutures are poorly understood at the molecular genetic level. Here we report on the function and expression pattern of the LIM-homeodomain gene, lmx1b, during calvarial development. Lmx1b is expressed in the neuroepithelium underlying portions of the developing skull and in cranial mesenchyme which contributes to portions of the cranial vault. Lmx1b is essential for proper patterning and morphogenesis of the calvaria since the supraoccipital and interparietal bones of lmx1b mutant mice are either missing or severely reduced. Moreover, lmx1b mutant mice have severely abnormal sutures between the frontal, parietal, and interparietal bones. Our results indicate that lmx1b is required for multiple events in calvarial development and suggest possible genetic interaction with other genes known to regulate skull development and suture formation.

Topoisomerase IIalpha expression in breast cancer: correlation with outcome variables

Topoisomerase IIalpha (topo IIalpha) plays a key role in DNA replication and is a target for multiple chemotherapeutic agents. In breast cancer, topo II expression has been linked to cell proliferation and HER2/neu protein overexpression. However, its relationship with outcome variables is not well established. Formalin-fixed, paraffin-embedded primary breast cancers from 184 women (mean age, 60 years) were stained for topo II by automated immunohistochemistry. A topo II expression index (TI) was determined by counting the number of positive cells per high-power field and calculating an overall mean number of positive cells per high-power field. Tumors with a TI of more than 1 were considered positive, and those with a TI of 1 or less were considered negative. A cell proliferation index was determine d by automated immunohistochemistry using the MIB-1 antibody in an identical technique. HER-2/neu gene amplification (HER-2 amp) was determined by automated fluorescence in situ hybridization using the Ventana unique sequence probe. Fifty-nine (32%) of the tumors had a TI greater than 1. On univariate analysis, increased topo II expression correlated with decreased patient survival (p = .001), advanced tumor stage (p = .034), lymph node metastasis (p = .018), and HER-2 amp (p = .016). Tumor stage (p < .0001), node-positive status (p < .0001), tumor grade (p = .025), HER-2 amp (p < .0001), and MIB-1 overexpression (p = .002) also correlated with survival on univariate analysis. Topo II expression did not correlate with tumor size, grade, estrogen receptor/progesterone receptor status, or disease recurrence. On multivariate analysis, stage (p < .0001), lymph node metastasis (p < .0001), and tumor grade (p = .002) all independently predicted disease-related death. Increased topo II expression is associated with an aggressive form of breast cancer featuring HER-2 amp and predicts disease-related death, lymph node metastasis, and advanced tumor stage.

A second independent pathway for development of mesencephalic dopaminergic neurons requires Lmx1b

We identified the LIM homeodomain transcription factor Lmx1b in the mesencephalic dopamine (mesDA) systems of embryos and adults. Analysis of spatiotemporal expression in Lmx1b null mutants and wild-type mice implicated a cascade involving Lmx1b in the early development of mesDA neurons. Although disruption of this cascade did not block induction of tyrosine hydroxylase (TH), a key enzyme in DA synthesis, or Nurr1, a nuclear hormone receptor, Lmx1b knockout mice failed to induce the mesDA-specific homeodomain gene Ptx3 in TH-positive neurons. Eventually, this small set of TH-positive neurons was lost during embryonic maturation. The data suggest that at least two molecular cascades operate during the specification of the mesDA system, one specifying neurotransmitter phenotype and another essential for other aspects of mesDA neuron differentiation.

Air distribution during in situ air sparging: an overview of mathematical modeling

The performance of in situ air sparging is controlled by the distribution of air pathways in the subsurface, which is in turn controlled by the structure of the medium to be sparged. The specific pathways that the air follows are determined, at the grain scale, by the distribution of air entry pressures of the pores. At the field scale, pore size distributions are usually correlated with heterogeneous structures (e.g. layers) within the medium, which control the macroscopic distribution of the air. The processes that produce an observed air distribution at a particular site are complicated, and are potentially well suited to modeling with multiphase flow models. Recent numerical modeling of heterogeneous media appears to successfully represent expected distributions of air; however, current models do not provide a tool to predict sparging performance. For this to be the case, the models need to represent the detailed structure of the medium at the site to be studied, as well as to capture the relevant aspects of the discrete air/water distribution (i.e., represent air channels at the centimeter or smaller scale). This will, in general, require a level of site data that is not available and numerical models that require many millions of computational elements. As a consequence, at least for the foreseeable future, numerical modeling of the air sparging process will continue to play a vital role as a conceptual tool with limited predictive capability at sites.

L-prolyl-l-leucyl-glycinamide and its peptidomimetic analog 3(R)-[(2(S)-pyrrolidylcarbonyl)amino]-2-oxo-1-pyrrolidineacetamide (PAOPA) attenuate haloperidol-induced c-fos expression in the striatum

Acute treatment of rats with haloperidol results in a rapid and transient increase in striatal c-fos mRNA and Fos immunoreactivity. The induction of immediate early genes by haloperidol may be involved in the development of extrapyramidal side effects. L-Prolyl-L-leucyl-glycinamide (PLG, or MIF-1) has been observed to antagonize the development of haloperidol-induced D(2) receptor supersensitivity in rats. We investigated the modulatory effects of PLG on haloperidol-induced c-fos and Fos protein expression in the rat striatum. We report that coadministration of either PLG or the potent analog of PLG, 3(R)-[(2(S)-pyrrolidylcarbonyl)amino]-2-oxo-1-pyrrolidineacetam ide (PAOPA), attenuated haloperidol-induced c-fos and Fos expression. Haloperidol induced [2 mg/kg, intraperitoneally (i.p.)] c-fos and Fos expression by 500% and 100%, respectively. These responses were attenuated by 170% and 75%, respectively, when coadministered with PLG (20 mg/kg, i.p.) or by 79% by PAOPA (10 microg/kg, i.p.).

LMX1B, a LIM homeodomain class transcription factor, is necessary for normal development of multiple tissues in the anterior segment of the murine eye

Proper development of the anterior segment of the mammalian eye is critical for normal ocular function. Indeed, several congenital syndromes associated with anterior segment anomalies can lead to impaired vision and glaucoma. One such syndrome is nail patella syndrome (NPS), caused by haploinsufficiency for the LIM-homeodomain transcription factor LMX1B. Although mutations in LMX1B cosegregate with NPS, whether these mutations cause the glaucoma associated with NPS is not known. Here, we provide evidence that the LIM-homeodomain transcription factor lmx1b is an essential regulator of murine anterior segment development. Mice that are homozygous for a targeted mutation of lmx1b display iris and ciliary body hypoplasia, and cornea stromal defects. In addition, two cDNAs normally downregulated in presumptive cornea, mf1 and mfh1, exhibit persistent expression, while keratocan, a keratin sulfate proteoglycan expressed by keratocytes, is not detected in mutant corneas. Moreover, ultrastructural examination of homozygous mutants indicates that corneal collagen fibrillogenesis is perturbed. Taken together, our studies suggest a developmental etiology for glaucoma in NPS patients and highlight lmx1b as an essential regulator of anterior segment morphogenesis and patterning. genesis 26:15-25, 2000.

Prognostic significance of p34cdc2 cyclin-dependent kinase and MIB1 overexpression, and HER-2/neu gene amplification detected by fluorescence in situ hybridization in breast cancer

The HER-2/neu oncogene, localized to chromosome 17q, shares substantial homology with the epidermal growth factor receptor. HER-2/neu gene amplification and protein overexpression have been associated with poor prognosis in breast cancer. Formalin-fixed paraffin-embedded primary invasive breast cancer tissues from 135 women were tested for HER-2/neu gene amplification by automated fluorescence in situ hybridization (FISH) using a sequence probe. The tumors also were evaluated by immunohistochemistry for proliferation markers Ki 67 (MIB1) and p34cdc2 cyclin-dependent kinase. Patients were followed up for a mean of 61 months. There were 70 node-negative and 65 node-positive cases. Ki 67 and p34cdc2 proliferation marker overexpression, HER-2/neu oncogene amplification, large tumor size, high tumor grade, advanced tumor stage, positive lymph node status, and distant metastasis at the time of diagnosis predicted disease-related death in combined node-negative and node-positive breast cancer. HER-2/neu gene amplification, tumor stage, lymph node metastasis, tumor grade, and distant metastasis at the time of diagnosis independently predicted disease outcome. HER-2/neu amplification detected by FISH also predicted disease-related death independent of lymph node status, tumor grade, and distant metastasis in breast cancer patients who received adjuvant therapy.

MR visualization of the popliteomeniscal fascicles

OBJECTIVE

Although the popliteomeniscal fascicles are important stabilizers of the lateral meniscus, there have been few studies of their MR appearance. We wished to determine: (1) whether the fascicles are normally seen on MR imaging, and (2) whether certain imaging factors influenced their visualization.

DESIGN AND PATIENTS

We reviewed the sagittal MR images of 66 consecutive patients who had no evidence of injury to the lateral compartment. We determined the frequencies of MR visualization of the superior and inferior popliteomeniscal fascicles, and whether visualization was affected by the weighting of spin echo sequences, the presence of a joint effusion, slice placement relative to the fascicles, and windowing of the images.

RESULTS AND CONCLUSIONS

Both popliteomeniscal fascicles were seen in 64 of the 66 patients. The fascicles were better seen on T2-weighted images than on proton-density weighted images (P<0.01). On the T2-weighted images, fascicle visualization was not significantly affected by the presence or absence of an effusion, slice placement or image windowing (P=0.2 to 1.0). On proton-density weighted images, fascicle visualization was significantly improved when high-contrast windowing was used (P=0.04). In conclusion, we found that the popliteomeniscal fascicles are normally seen on MR imaging of the knee when there are no lateral compartment injuries. The fascicles are significantly better visualized on T2-weighted than on proton-density weighted images. Visualization is not significantly affected by the presence of an effusion or slice placement.

Function of Rieger syndrome gene in left-right asymmetry and craniofacial development

Rieger syndrome, an autosomal dominant disorder, includes ocular, craniofacial and umbilical abnormalities. The pitx2 homeobox gene, which is mutated in Rieger syndrome, has been proposed to be the effector molecule interpreting left-right axial information from the early embryonic trunk to each organ. Here we have used gene targeting in mice to generate a loss-of-function allele that would be predicted to result in organ randomization or isomerization. Although pitx2-/- embryos had abnormal cardiac morphogenesis, mutant hearts looped in the normal direction. Pitx2-/- embryos had correctly oriented, but arrested, embryonic rotation and right pulmonary isomerism. They also had defective development of the mandibular and maxillary facial prominences, regression of the stomodeum and arrested tooth development. Fgf8 expression was absent, and Bmp4 expression was expanded in the branchial-arch ectoderm. These data reveal a critical role for pitx2 in left-right asymmetry but indicate that pitx2 may function at an intermediate step in cardiac morphogenesis and embryonic rotation.

Synthesis and dopamine receptor modulating activity of unsubstituted and substituted triproline analogues of L-prolyl-L-leucyl-glycinamide (PLG)

Triprolines Pro-Pro-Pro-NH2 (4), Pro-Pro-D-Pro-NH2 (5), Pro-Pro(trans-3-Me)-D-Pro-NH2 (6), and Pro-Pro(cis-3-Me)-D-Pro-NH2 (7) were made as conformationally constrained analogues of Pro-Leu-Gly-NH2. Triprolines 4-6 produced significant increases in the high- and low-affinity state ratio (RH/RL) of the dopamine receptor, but only 4 was found to increase apomorphine induced rotations in 6-hydroxydopamine-lesioned rats.

Synthesis and dopamine receptor modulating activity of substituted bicyclic thiazolidine lactam peptidomimetics of L-prolyl-L-leucyl-glycinamide

6-Substituted bicyclic thiazolidine lactam peptidomimetics of Pro-Leu-Gly-NH(2) (1) were synthesized to test the hypothesis that incorporation of a hydrophobic side chain into the bicyclic thiazolidine lactam scaffold would further enhance the dopamine receptor modulating activity of such peptidomimetics. The substituents employed were the isobutyl, butyl, and benzyl groups to give peptidomimetics 3-5, respectively. These peptidomimetics were evaluated in vivo as modulators of apomorphine-induced rotational behavior in the 6-hydroxydopamine-lesioned rat model of hemiparkinsonism and were compared with the unsubstituted bicyclic thiazolidine lactam Pro-Leu-Gly-NH(2) peptidomimetic 2. Peptidomimetics 3-5 each affected rotational behavior in a bell-shaped dose-response relationship producing maximal increases of 44% (1 microgram/kg,ip), 56% (0.1 microgram/kg,ip), and 30% (1 microgram/kg, ip), respectively. In comparison, unsubstituted peptidomimetic 2 increased rotational behavior by only 23% at a dose of 0.1 microgram/kg, ip.

Identification and expression of a novel family of bHLH cDNAs related to Drosophila hairy and enhancer of split

In this report we describe the initial characterization of murine, human, and Drosophila hesr-1 (for hairy and enhancer of split related-1) a novel evolutionary conserved family of hairy/enhancer of split homologs. Hesr-1 cDNAs display features typical of hairy and enhancer of split-type bHLH proteins including a N-terminal bHLH domain a conserved orange domain immediately C-terminal to the bHLH region. Despite their similarity to known hairy/enhancer of split homologs, hesr-1 cDNAs are divergent members of the hairy and enhancer of split bHLH family since the degree of sequence identity within the bHLH and their nearest homologs are relatively low. Moreover, the tetrapeptide motif, WRPW, which is found in all hairy and enhancer of split family members, is not present in hesr-1. Rather, a variant of this motif, YRPW, is found. Analysis of embryonic murine hesr-1 expression by in situ hybridization reveals strong expression in the somitic mesoderm, the central nervous system, the kidney, the heart, nasal epithelium, and limbs indicating a role for hesr-1 in the development of these tissues. Like the enhancer of split cDNAs in Drosophila, we show that hesr-1 expression depends critically on signaling through the notch pathway in murine embryos, suggesting that aspects of hesr-1 regulation and function might also be evolutionary conserved.

Modulation of agonist stimulated adenylyl cyclase and GTPase activity by L-pro-L-leu-glycinamide and its peptidomimetic analogue in rat striatal membranes

L-prolyl-L-leucyl-glycinamide (PLG), also known as melanocyte-stimulating hormone release inhibiting factor (MIF-1), is an endogenous brain tripeptide. Previous studies have shown that PLG, and its peptidomimetic analogues, render dopamine D2 receptors more responsive to agonists by maintaining the high-affinity binding state of the receptors. In the present study, we examined the effect PLG and its analogue 3(R)-[(2(S)-pyrrolidylcarbonyl)amino]-2-oxo-1-pyrrolidineacetam ide (PAOPA) on dopamine-stimulated adenylyl cyclase and NPA-stimulated GTPase activity in rat striatal membranes. Dopamine-stimulated adenylyl cyclase activity was inhibited by both PLG and PAOPA in a dose-dependent manner, whereas R(-)-propylnorapomorphine (NPA)-stimulated low Km GTPase activity was significantly increased by 1 microM PLG or 1 nM PAOPA. These results suggest that PLG and PAOPA maintain the high affinity state of the D2 receptor by increasing GTP hydrolysis through stimulation of agonist-induced GTPase activity.

Effects of in-season (5 weeks) creatine and pyruvate supplementation on anaerobic performance and body composition in American football players

The purpose of this investigation was to study the efficacy of two dietary supplements on measures of body mass, body composition, and performance in 42 American football players. Group CM (n = 9) received creatine monohydrate, Group P (n = 11) received calcium pyruvate, Group COM (n = 11) received a combination of calcium pyruvate (60%) and creatine (40%), and Group PL received a placebo. Tests were performed before (T1) and after (T2) the 50 week supplementation period, during which the subjects continued their normal training schedules. Compared to P and PL, CM and COM showed significantly greater increases for body mass, lean body mass, 1 repetition maximum (RM) bench press, combined 1 RM squat and bench press, and static vertical jump (SVJ) power output. Peak rate of force development for SVJ was significantly greater for CM compared to P and PL. Creatine and the combination supplement enhanced training adaptations associated with body mass/composition, maximum strength, and SVJ; however, pyruvate supplementation alone was ineffective.

Interaction of Ihh and BMP/Noggin signaling during cartilage differentiation

Bone morphogenetic proteins (BMPs) have been implicated in regulating multiple stages of bone development. Recently it has been shown that constitutive activation of the BMP receptor-IA blocks chondrocyte differentiation in a similar manner as misexpression of Indian hedgehog. In this paper we analyze the role of BMPs as possible mediators of Indian hedgehog signaling and use Noggin misexpression to gain insight into additional roles of BMPs during cartilage differentiation. We show by comparative analysis of BMP and Ihh expression domains that the borders of Indian hedgehog expression in the chondrocytes are reflected in changes of the expression level of several BMP genes in the adjacent perichondrium. We further demonstrate that misexpression of Indian hedgehog appears to directly upregulate BMP2 and BMP4 expression, independent of the differentiation state of the flanking chondrocytes. In contrast, changes in BMP5 and BMP7 expression in the perichondrium correspond to altered differentiation states of the flanking chondrocytes. In addition, Noggin and Chordin, which are both expressed in the developing cartilage elements, also change their expression pattern after Ihh misexpression. Finally, we use retroviral misexpression of Noggin, a potent antagonist of BMP signaling, to gain insight into additional roles of BMP signaling during cartilage differentiation. We find that BMP signaling is necessary for the growth and differentiation of the cartilage elements. In addition, this analysis revealed that the members of the BMP/Noggin signaling pathway are linked in a complex autoregulatory network.

Cyclobutane quisqualic acid analogues as selective mGluR5a metabotropic glutamic acid receptor ligands

The conformationally constrained cyclobutane analogues of quisqualic acid (Z)- and (E)-1-amino-3-[2'-(3',5'-dioxo-1',2', 4'-oxadiazolidinyl)]cyclobutane-1-carboxylic acid, compounds 2 and 3, respectively, were synthesized. Both 2 and 3 stimulated phosphoinositide (PI) hydrolysis in the hippocampus with EC50 values of 18 +/- 6 and 53 +/- 19 microM, respectively. Neither analogue stimulated PI hydrolysis in the cerebellum. The effects of 2 and 3 were also examined in BHK cells which expressed either mGluR1a or mGluR5a receptors. Compounds 2 and 3 stimulated PI hydrolysis in cells expressing mGluR5a but not in those cells expressing mGluR1a. The EC50 value for 2 was 11 +/- 4 microM, while that for 3 was 49 +/- 25 microM. Both 2 and 3 did not show any significant effect on cells expressing the mGluR2 and mGluR4a receptors. In addition, neither compound blocked [3H]glutamic acid uptake into synaptosomal membranes, and neither compound was able to produce the QUIS effect as does quisqualic acid. This pharmacological profile indicates that 2 and 3 are selective ligands for the mGluR5a metabotropic glutamic acid receptor.

Red cell distribution and the recruitment of pulmonary diffusing capacity

The distribution of red blood cells in alveolar capillaries is typically nonuniform, as shown by intravital microscopy and in alveolar tissue fixed in situ. To determine the effects of red cell distribution on pulmonary diffusive gas transport, we computed the uptake of CO across a two-dimensional geometric capillary model containing a variable number of red blood cells. Red blood cells are spaced uniformly, randomly, or clustered without overlap within the capillary. Total CO diffusing capacity (DLCO) and membrane diffusing capacity (DmCO) are calculated by a finite-element method. Results show that distribution of red blood cells at a fixed hematocrit greatly affects capillary CO uptake. At any given average capillary red cell density, the uniform distribution of red blood cells yields the highest DmCO and DLCO, whereas the clustered distribution yields the lowest values. Random nonuniform distribution of red blood cells within a single capillary segment reduces diffusive CO uptake by up to 30%. Nonuniform distribution of red blood cells among separate capillary segments can reduce diffusive CO uptake by >50%. This analysis demonstrates that pulmonary microvascular recruitment for gas exchange does not depend solely on the number of patent capillaries or the hematocrit; simple redistribution of red blood cells within capillaries can potentially account for 50% of the observed physiological recruitment of DLCO from rest to exercise.

Red cell distribution and the recruitment of pulmonary diffusing capacity

The distribution of red blood cells in alveolar capillaries is typically nonuniform, as shown by intravital microscopy and in alveolar tissue fixed in situ. To determine the effects of red cell distribution on pulmonary diffusive gas transport, we computed the uptake of CO across a two-dimensional geometric capillary model containing a variable number of red blood cells. Red blood cells are spaced uniformly, randomly, or clustered without overlap within the capillary. Total CO diffusing capacity (DLCO) and membrane diffusing capacity (DmCO) are calculated by a finite-element method. Results show that distribution of red blood cells at a fixed hematocrit greatly affects capillary CO uptake. At any given average capillary red cell density, the uniform distribution of red blood cells yields the highest DmCO and DLCO, whereas the clustered distribution yields the lowest values. Random nonuniform distribution of red blood cells within a single capillary segment reduces diffusive CO uptake by up to 30%. Nonuniform distribution of red blood cells among separate capillary segments can reduce diffusive CO uptake by >50%. This analysis demonstrates that pulmonary microvascular recruitment for gas exchange does not depend solely on the number of patent capillaries or the hematocrit; simple redistribution of red blood cells within capillaries can potentially account for 50% of the observed physiological recruitment of DLCO from rest to exercise.

Synthesis and dopamine receptor modulating activity of novel peptidomimetics of L-prolyl-L-leucyl-glycinamide featuring alpha,alpha-disubstituted amino acids

In the present study, L-prolyl-L-leucyl-glycinamide (1) peptidomimetics 3a-3d and 4a-4d were synthesized utilizing alpha, alpha-disubstituted amino acids. These analogues were designed to explore the conformational effects of constraints at the phi3 and psi3 torsion angles. Constrained conformations were verified by the use of X-ray crystallography and circular dichroism. The effects of Pro-Leu-Gly-NH2 analogues 3a-3d and 4a-4d on enhancing rotational behavior induced by apomorphine in the 6-hydroxydopamine-lesioned animal models of Parkinson's disease were studied. The ability of these peptidomimetics to increase the binding of agonist N-propylnorapomorphine (NPA) to the dopamine D2 receptor was also examined. Extended analogue Pro-Leu-Deg-NH2 was the most active compound of this series. It was 10 times more potent and almost 2 times more effective than 1 in increasing apomorphine-induced rotations (56 +/- 15% at 1.0 mg/kg ip) and in enhancing [3H]NPA specific binding (40%).