Immunohistochemical Localization of Cholecystokinin Octapeptide (CCK-8) Neurons in the Mesencephalon of the Rat

Immunohistochemical localization of cholecystokinin octapeptide (CCK-8) neurons in the mesencephalon was studied with ABC technique and visualized with both GDN (glucose oxidase-DAB-nickel) and PAP methods. 12 Wistar rats were perfused with phosphate buffered 4％ paraformaldehyde. Cryostat sections 40 μm in thickness were made, and incubated with rabbit anti-CCK-8 serum (INC,     

Oncothanin,a Peptide from the α 3 Chain of Type IV Collagen,Modifies Endothelial Cell Function and Inhibits Angiogenesis

Previous reports from our laboratory have shown that basement membrane (BM) collagen from anterior lens capsule type IV collagen (ALC-COL IV) and peptides from the noncollagenous domain of the α 3(IV) chain, corresponding to residues 185-203 and 179-208, inhibit tumor cell proliferation, specifically through the interaction of the -SNS- tripeptide (residues 189-191) with the CD47/αv β₃ integrin receptor complex. Data presented here demonstrate that the α 3(IV)185-203 and the α 3(IV)179-208 peptides, designated as oncothanin, regulate endothelial cell (EC) proliferation, adhesion, and motility that ultimately influence angiogenesis. The data also indicate that oncothanin, when used as a chemoattractant, greatly enhanced EC chemotaxis. In contrast, pretreatment of EC with oncothanin inhibited chemotaxis toward several different chemoattractants. When oncothanin was used as a substrate, it enhanced EC adhesion that was inhibited when pretreated with same. Analysis of angiogenesis by EC differentiation (tube formation), aortic ring microvessel formation, and the chorioallantoic membrane assay demonstrate that oncothanin, but not the control medium or peptides, inhibits angiogenesis. In the EC differentiation assay, oncothanin completely inhibited tube formation at 25 μ g/ml, whereas peptides with comparable sequences, lacking the -SNS- sequence, from ALC-COL IV NC1 domains α 1 and α 2 chains failed to inhibit tube formation. The data support the hypothesis that ALC-COL IV and oncothanin inhibit angiogenesis by modulation of EC function.     

Localization of Cells Containing Transforming Growth Factor- α Precursor Immunoreactivity in the Basal Ganglia of the Adult Rat Brain

Abstract

Transforming growth factor-α-like immunoreactivity (TGF-α-ir) was visualized in the adult rat forebrain using three antisera directed against carboxyterminal sequences in the TGF-α precursor. Using immunoperoxidase and immunofluorescence techniques with all three antisera, TGF-λ-ir was found to be present in a subpopulation of astrocytes in the forebrain. Striatal and pallidal regions of the basal ganglia were studied in detail. In the striatum, there was an uneven distribution of astrocytes containing TGF-α-ir, with the greatest number in the dorsal medial third of the caudate-putamen and the overlying corpus callosum/external capsule. In addition, the region of the caudate-putamen bordering the globus pallidus contained numerous clusters of TGF-α-ir astrocytes. The globus pallidus itself contained numerous and more evenly distributed TGF-α-ir astrocytes. Other pallidal structures-including the ventral pallidum, entopeduncular nucleus, and substantia nigra pars reticulata–contained moderate numbers of TGF-α-ir astrocytes. These results suggest that TGF-α precursor is present and, perhaps, synthesized in astrocytes. A related growth factor, epidermal growth factor (EGF), has also been reported to be present in pallidal regions of rat brain. Therefore, the TGF-α/EGF family of trophic factors may play an important role in the function of the central nervous system.     

Cloning and Relative Expression Analysis of Rat Stromal Cell Derived Factor-1 (SDF-1): SDF-1 α mRNA Is Selectively Induced in Rat Model of Myocardial Infarction

Stromal cell derived factor-1 (SDF-1) is a member of the non-ELR subfamily of CXC chemokines. SDF-1 and its receptor, CXCR4, are essential for cardiogenesis, hematopoiesis, and vasculogenesis during embryonic development, in addition to involvement in chemotaxis of leukocyte subsets and endothelial cells. In order to study SDF-1 expression in a rat model of myocardial infarction, we cloned and functionally expressed the rat SDF-1 orthologue. Rat SDF-1 is highly conserved, with >95% identity to its known human, feline, and murine counterparts. Constitutive expression of SDF-1 mRNA was observed in heart, brain, liver, and kidney. Significantly, apart from the SDF-1 and splice variants, expression of the recently identified SDF-1 was uniquely abundant in the heart. SDF-1 mRNA was selectively induced in permanent coronary artery occlusion model of myocardial infarction in rat, while SDF-1 remained unchanged. Such modulation of SDF-1 mRNA expression may be indicative of its role in the inflammatory events in cardiovascular disease.     

RETRACTED ARTICLE: An Experimental Study of the Neurogenic and the Immunological Contribution to “Tennis Elbow” in Rats

In the present study the content of substance P (SP)-, neurokinin A (NKA)-, calcitonin gene-related peptide (CGRP)- and neuropeptide Y (NPY)-like immunoreactivity (-LI) was measured in rats cerebrospinal fluid (CSF), plasma and perfusates (PF) from both elbow enthesis during acute inflammation. Either substance P, SP, (10–5 M, 0.01 ml) or human recombinant interleukin-1 (hrIl-1 , 0.01 ml) were injected into the right enthesis of the extensor carpi radialis brevis (ECRB). The left ECRB and both ECRBs of control rats, were injected with 0.01 ml saline. Samples of CSF, plasma and PF from both ECRBs were obtained at 2, 6, and 24 h following injection and neuropeptide-LI was analysed by specific radioimmunoassays. Neuropeptide-LI was compared with control values and between the treated groups. In both treated groups NKA- and CGRP-LI was increased in CSF and NKA-LI decreased in plasma, while CGRP- and NPY-LI were raised to a similarly significant degree in the enthesis of the ECRB. SP-LI was increased in ECRB PF in comparison with controls and NKA-LI levels were higher in the hrIl-1 group both in comparison with controls and between treated groups. In summary an unilateral injection of either SP or hrIl-1 into the enthesis of the ECRB of the rat showed a similar influence at 2, 6, and 24 h following injection. The most pronounced changes in neuropeptide-LI occurred in the ECRB PF of both treated groups.     

High Frequency Oscillations in the Ripple Band (80–250 Hz) in Scalp EEG: Higher Density of Electrodes Allows for Better Localization of the Seizure Onset Zone

High frequency oscillations (HFO) are known as markers of epileptic areas in intracranial EEG and possibly scalp EEG. We compared distributions of HFO in the ripple band (80–250 Hz) in intracranial and scalp EEG with either a conventional 10–20-montage (10–20-EEG) or a high density recording using 128 electrodes (HD-EEG). HFO were visually identified, in all intracranial EEG channels (80–500 Hz) and all channels of the 10–20-EEG (scalp EEG 80–250 Hz). For the HD-EEG, HFO were analyzed in regions of interest using areas with HFO as seen on the 10–20-EEG as well as areas in the clinically-defined seizure onset zone (SOZ). 13 patients were included in the study, of whom 12 showed HFO in the ripple band. In 8 patients HD-EEG revealed additional regions of ripples compared to the 10–20-EEG. With HD-EEG, areas of highest ripple rates were corresponding between scalp and intracranial EEG in 7 patients (58%) and 8 (67%) patients showed highest ripple rates over the SOZ. In contrast, with 10–20-EEG only 2 patients (17%) had corresponding areas of highest ripple rates and only 3 patients (23%) showed highest ripple rates over the SOZ. HD-EEG proved to be better to identify scalp HFO in the ripple band compared to standard 10–20-EEG. Moreover, ripples in 10–20-EEG seem to lead to false localization of epileptic areas. In contrast ripples detected with HD-EEG were located over the seizure onset zone and maybe a promising tool to localize epileptic tissue in the future.     

Left Ventricular Contractility is Impaired Following Myocardial Infarction in the Pig and Rat: Assessment by the End Systolic Pressure–Volume Relation Using a Single-Beat Estimation Technique and Cine Magnetic Resonance Imaging

The end systolic pressure–volume relation (ESPVR) has been shown to be a relatively load independent measure of left ventricular (LV) contractility. Recently, several single-beat ESPVR computation methods have been developed, enabling the quantification of LV contractility without the need to alter vascular loading conditions on the heart. Using a single-beat ESPVR method, which has been validated previously in humans and assumes that normalized elastance is constant between individuals of a species, we studied the effects of myocardial infarction on LV contractility in two species, the rat and the pig. In our studies, LV pressure was acquired invasively and LV volume determined noninvasively with magnetic resonance imaging, at one week postinfarction in pigs and at 12 weeks postinfarction in rats. Normalized systolic elastance curves in both animal species were not statistically different from that of humans. Also, the slope of the ESPVR decreased significantly following infarction in both species, while the volume-axis intercept was unaffected. These results indicate that a single-beat ESPVR method can be used to measure the inotropic response of the heart to myocardial infarction, and that the basis for this method (i.e., constant normalized elastance) is applicable to a variety of mammalian species. © 2000 Biomedical Engineering Society. PAC00: 8719Uv, 8761Lh, 8719Hh, 8719Rr, 8719Ff     

BDNF Meditated trkB and Synapsin I Changes within the Hippocampus after Mild Traumatic Brain Injury in Rat:Reflections of Injury-induced Neuroplasticity

1 IntroductionTraumatic brain injury (TBI) can produce chronic cognitive learning/memory deficits that are thought to be mediated, in part, by impaired hippocampal function. Brain-derived neurotrophic factor (BDNF), its signal transduction receptor trkB and its downstream effector synapsin I are involved in this period. BDNF, trkB and the slope of field excitatory post-synaptic potential(fEPSP) were measured in the hippocampus of rat after fluid percussion brain injury (FPI). Isofluora…     

Control of Type I Collagen Systhesis: Evidence for Pretranslational Coordination of Proα1 (I) and Proα2 (I) Chain Synthesis in Embryonic Chick Bone

The normal type I collagen molecule contains two αl (I) chains and one α2 (I) chain. In embryonic chick calvaria, the two chains are synthesized in a 2: 1 ratio, and total polysomes from this tissue contain twice as much mRNA for proal (I) as for proα2 (I).⁹ To further investigate the mechanism by which synthesis may be coordinated, RNA isolated from various cell fractions of embryonic chick calvaria was translated in a rabbit reticulocyte lysate cell-free system. The procollagen chain products were separated by gel-electrophoresis and densitometrically quantitated from autoradiograms of the gels. Total cellular RNA, total cytoplasmic RNA, and polysomal RNA each directed the synthesis of proal (I) and proa2 (I) in a proportion of 2: 1, whereas no procollagen mRNA activity was found in nonpolysomal cytoplasmic RNA. These results indicate that in the chick bone cells, all compartments contain twice as much proal (I) mRNA as proa2 (I) mRNA, and that virtually all procollagen mRNA in the cytoplasm is poly some-bound. The coordination of procollagen chain synthesis thus presumably occurs at a pretranslational level, through differential rates of formation and/or degradation of the two mRNAs.     

Emergence of SCCmec Type IV and SCCmec Type V Methicillin-Resistant Staphylococcus aureus Containing the Panton-Valentine Leukocidin Genes in a Large Academic Teaching Hospital in Central Switzerland: External Invaders or Persisting Circulators?

The hospital epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) has changed in the past few years due to the encroachment of community-associated MRSA (CA-MRSA) strains into health care settings. MRSA strains that were isolated during a 2-year period from patients of the Luzerner Kantonsspital were analyzed to elucidate their epidemiology. Moreover, extended surveillance of individuals who were contacts of those patients was carried out for 6 months to identify the routes of spread and to assess the quality of the infection control measures used in our setting. Patient data were collected to distinguish CA-MRSA strains from health care-associated MRSA (HA-MRSA) strains by epidemiological criteria, as defined by the Centers for Disease Control and Prevention (CDC). On the basis of the CDC definition, the majority of the strains were considered to be HA-MRSA. However, 87% of them belonged to staphylococcal cassette chromosome mec (SCCmec) types IV and V, which are traditionally associated with CA-MRSA. Surprisingly, classical nosocomial SCCmec types I and II represented a minority, whereas SCCmec type III was completely absent. By PFGE analysis, four predominant clonal lineages and 21 highly variable sporadic genotypes were detected. Twenty-eight percent of the MRSA strains studied carried the genes encoding the Panton-Valentine leukocidin (PVL), of which 21% and 83% were associated with SCCmec types IV and V, respectively. Among 289 contact individuals screened for MRSA carriage throughout the extended surveillance, a single secondary patient was discovered. The possibility of nosocomial transmission could be excluded. The high proportions of SCCmec type IV and V strains as well as PVL-positive strains suggest strong infiltration of CA-MRSA into our institution. Moreover, the low endemic prevalence of MRSA demonstrates that current infection control measures are sufficient to limit its spreading and the emergence of large epidemic outbreaks.Methicillin-resistant Staphylococcus aureus (MRSA), one of the most common nosocomial pathogens, usually carries genetic elements that confer resistance to a broad range of antibiotics (2, 25). Methicillin resistance in staphylococci is based on the expression of a modified penicillin-binding protein (PBP), PBP 2a, which is encoded by the mecA gene. This gene is located on the staphylococcal cassette chromosome mec (SCCmec), a mobile genetic element integrated in the chromosome (6, 23) which also carries the genes for specific recombinases (ccr) necessary for its excision and integration (24). On the basis of the mec and ccr complex sequences, SCCmec is classified into types I to VII (1, 25). Previous studies showed that health care-associated (HA) MRSA (HA-MRSA) infections are generally caused by multidrug-resistant strains harboring SCCmec types I, II, and III but rarely SCCmec type IV (26, 38, 47, 52). On the other hand, community-associated (CA) MRSA (CA-MRSA) strains carry SCCmec type IV, V, or VII; are commonly susceptible to the majority of non-β-lactam antibiotics; frequently produce the Panton-Valentine leukocidin (PVL); and differ in their pulsed-field gel electrophoresis (PFGE) patterns (38). Recent studies have reported that CA-MRSA strains are spreading in hospital settings and are replacing traditional HA-MRSA strains (44, 46, 47, 52).Although the average prevalence of MRSA strains in Switzerland has been lower than that in the surrounding countries—between 0 and 6% of the first isolates of S. aureus recovered, except in Geneva, where the rate is 20% (2, 17, 19)—the incidence of MRSA infections is increasing. Even though there are epidemiological data for MRSA in Switzerland (2, 17, 20, 44, 47), the extent of the problem in the central part of Switzerland is unknown. In this study, we aimed at assessing the frequency, diversity, and clonal distribution of MRSA strains that were isolated at the Luzerner Kantonsspital (LUKS) between January 2007 and December 2008, in order to elucidate their origin and ways of circulation within our institution. Moreover, in a 6-month prospective study, we evaluated the effects of extended health care-associated hygienic measures on nosocomial MRSA transmission.