The R7 subfamily of RGS proteins assists tachyphylaxis and acute tolerance at mu-opioid receptors.

Members of the R7 subfamily of regulators of G-protein signaling (RGS) proteins (RGS6, RGS7, RGS9-2, and RGS11) are found in the mouse CNS. The expression of these proteins was effectively reduced in different neural structures by blocking their mRNA with antisense oligodeoxynucleotides (ODNs). This was achieved without noticeable changes in the binding characteristics of labeled beta-endorphin to opioid receptors. Knockdown of R7 proteins enhanced the potency of antinociception promoted by morphine and [D-Ala(2), N-MePhe(4), Gly-ol(5)]-enkephalin (DAMGO)-both agonists at mu-opioid receptors. The duration of morphine analgesia was greatly increased in RGS9-2 and in RGS11 knockdown mice. The impairment of R7 proteins brought about different changes in the analgesic activity of selective delta agonists. Knockdown of RGS11 reduced [D-Ala(2)]deltorphin II analgesic effects. Those of RGS6 and RGS9-2 proteins caused [D-Ala(2)]deltorphin II to produce a smoothened time-course curve-the peak effect blunted and analgesia extended during the declining phase. RGS9-2 impairment also promoted a similar pattern of change for [D-Pen(2,5)]-enkephalin (DPDPE). RGS7-deficient mice showed an increased response to both [D-Ala(2)]deltorphin II and DPDPE analgesic effects. A single intracerebroventricular (i.c.v.) ED(80) analgesic dose of morphine gave rise to acute tolerance in control mice, but did not promote tolerance in RGS6, RGS7, RGS9-2, or RGS11 knockdown animals. Thus, R7 proteins play a critical role in agonist tachyphylaxis and acute tolerance at mu-opioid receptors, and show differences in their modulation of delta-opioid receptors.     

HLA-B*27 subtyping by PCR-RFLP in Spanish patients with ankylosing spondyiitis

Abstract: We describe the use of restriction analysis on PCR-amplified DNA for detecting all B*27 subtypes except B*2710 and B*2711 (i.e. from B*2701 to B*2709). After detecting B*27 by Sty I, double digestions consisting of Sty I plus another informative enzyme led to subtype assignment. We used mismatched primers to create restriction sites when necessary. The method avoids group-specific amplifications and other laborious optimization procedures. It was successfully tested on a panel of well characterized cell lines covering different B*27 subtypes. Then, we studied a group of 57 ankylosing spondyiitis patients and 746 controls from the south of Spain. B*27 showed a very strong association with the disease (OR=211.27, P=\0˜7). B*2702 and B*2705 distribution in controls (20% and 77.1%, respectively) differed from previously reported data in the Spanish population. We unexpectedly found the B*2707 allele in our population (one control).     

Hepatic stellate cells and oxidative stress]

Hepatic fibrosis is a wound-healing response that takes place during chronic liver injury and is characterized by excessive production and deposition of extracellular matrix (ECM) components, mainly collagen type I. Hepatic stellate cells (HSC) are responsible for the excessive production of scar tissue during liver fibrosis. Activation of HSC, the main step in the development of hepatic fibrosis, is mediated by cytokines and reactive oxygen species (ROS) released by damaged hepatocytes and/or activated Kupffer cells and even HSC themselves. While HSC usually remain quiescent, in response to factors promoting liver injury they undergo activation and become highly proliferative and fibrogenic. Indeed a key feature of HSC activation is uncontrolled production of collagen type I. Collagen is a heterotrimeric protein composed of two a1 chains and one a2 chain forming a triple helix structure. Initiation of HSC activation is largely due to paracrine stimulation, whereas the perpetuation of such activated state involves autocrine as well as paracrine loops. This review focuses on the role of oxidant stress on the activation of stellate cells.     

Phenotype traits associated with different alleles at the RPS5 locus in Saccharomyces cerevisiae

Summary The RPS5 gene has been characterised through its ability to reduce invertase production by the SUC5 gene. In this paper we show that RPS5 acts by maintaining low levels of SUC5 mRNA. We also show that RPS5 acts on the SUC1 and SUC4 genes but not on SUC2 and SUC3, which are members of the SUC family. RPS5 also shows a pleiotropic effect on the amount of mitochondrial cytochromes.     

Cesarean section and maternal age in low-risk nulliparas.

The relationship between maternal age and cesarean section in low-risk nulliparas was analysed in 7454 perinatal clinical records selected from eleven databases of Latin American institutions obtained with a comprehensive perinatal information system. The risk of cesarean section in nulliparas between 29 and 49 years of age was found to be three times higher than that corresponding to pregnant women of lesser age. This clearly more aggressive obstetrical conduct could not be explained by the main indications for cesarean section.     

Effect of cyclosporin a on proteinuria in patients with Alport's syndrome

Eight patients with Alport's syndrome and massive proteinuria (129±60.57 mg/m² per hour) were treated with cyclosporin A (CyA) for 8 months. The average dose of CyA administered to all patients was 4.21±0.26 mg/kg per day and blood CyA levels of 63.4±4.1 ng/ml were attained. In five patients, proteinuria abated during the 3rd week of treatment. In the remaining three, all of whom had low creatinine clearance (82.0, 46.0 and 43.2 ml/min per 1.73 m² respectively), proteinuria persisted but at levels lower than before treatment: 32.5±15.9 mg/m² per hour versus 183.3±29.7 mg/m² per hour. No permanent decrease in creatinine clearance was observed in any of these patients throughout treatment. In those patients in whom proteinuria abated, it reappeared 2 weeks after discontinuation of CyA treatment. We observed no significant increases in angiotensin II plasma levels in our patients during CyA administration. Although we have shown that CyA will reduce massive proteinuria in patients with Alport's syndrome, we cannot yet recommend its use as a therapeutic measure.     

An Eph-related receptor protein tyrosine kinase gene segmentally expressed in the developing mouse hindbrain.

In search of genes possibly involved in the regulation of hindbrain segmentation, we have isolated mouse cDNA clones corresponding to putative protein kinase genes by polymerase chain reaction amplification of cDNA from 9.5-day-old embryo hindbrains. In situ hybridization analysis revealed that one of these genes, Sek, was expressed in an alternating segment-restricted pattern in the developing hindbrain. Isolation and analysis of Sek cDNAs covering the entire coding sequence indicated that Sek encoded a putative receptor protein tyrosine kinase, belonging to the Eph family. These data are consistent with a role of the Sek gene product in a signal transduction process involved in pattern formation in the hindbrain.     

Molecular characterization of a coxsackievirus A24 variant that caused an outbreak of acute haemorrhagic conjunctivitis in Spain, 2004

BACKGROUND: Coxsackievirus A24 variant is one of the major etiological agents involved in acute haemorrhagic conjunctivitis. STUDY DESIGN: An outbreak of acute hemorrhagic conjunctivitis occurred in the Southeast of Spain between September and November 2004. Cellular and molecular methods were used to identify and characterize the viral agent associated with the epidemic. RESULTS: Enterovirus was detected in the conjunctival swabs of 35 patients. None of the viruses isolated could be typed by conventional neutralization assays; however, amplification and sequencing of the 3'-end VP1 region of 19 of the samples identified coxsackievirus A24 variant as the serotype causing the outbreak. Phylogenetic analysis of the 5'-half VP1 region of the genome revealed that Spanish sequences, like other strains isolated during outbreaks of hemorrhagic conjunctivitis in American and African countries in 2003 and 2004, were closely related to the isolates detected in Korea (2002), thus proving their worldwide spread. CONCLUSIONS: This is the first report of an epidemic of acute hemorrhagic conjunctivitis due to a coxsackievirus A24 variant in Spain. Molecular typing in combination with phylogenetic analysis is useful to study the enterovirus epidemiology associated with epidemics.     

Prosthetic mitral valve endocarditis due to Ochrobactrum anthropi: case report

We describe a case of infective endocarditis in a prosthetic mitral valve due to Ochrobactrum anthropi. Although O. anthropi is an emerging pathogen in immunocompromised patients, infections with the bacterium have very rarely been documented in healthy hosts, and endocarditis is rare. To our knowledge, only two cases of O. anthropi endocarditis have been reported in the medical literature.