A prospective multicenter evaluation of direct molecular detection of blood stream infection from a clinical perspective.

BACKGROUND: Rapid diagnosis and appropriate antimicrobial therapy are of major importance to decrease morbidity and mortality in patients with blood stream infections (BSI). Blood culture, the current gold standard for detecting bacteria in blood, requires at least 24-48 hours and has limited sensitivity if obtained during antibiotic treatment of the patient. The aim of this prospective multicenter study was to clinically evaluate the application of a commercial universal 16S/18S rDNA PCR, SepsiTest™ (PCR-ST), directly on whole blood. METHODS: In total 236 samples from 166 patients with suspected sepsis were included in the study. PCR-ST results were compared to blood culture, the current gold standard for detecting BSI. Because blood cultures can give false-negative results, we performed an additional analysis to interpret the likelihood of bloodstream infection by using an evaluation based on clinical diagnosis, other diagnostic tests and laboratory parameters. RESULTS: Clinical interpretation of results defined the detected organism to be contaminants in 22 of 43 positive blood cultures (51.2 %) and 21 of 47 positive PCR-ST results (44.7 %). Excluding these contaminants resulted in an overall sensitivity and specificity of the PCR-ST of 66.7 and 94.4 % respectively. Of the 36 clinically relevant samples, 11 BSI were detected with both techniques, 15 BSI were detected with PCR-ST only and 10 with blood culture only. Therefore, in this study, SepsiTest™ detected an additional 71 % BSI compared to blood culture alone. CONCLUSIONS: More clinically relevant BSI were diagnosed by molecular detection, which might influence patient treatment. An improved SepsiTest™ assay suited for routine use can have additional value to blood culture in diagnosing bacteremia in septic patients.

Antibacterial biodegradable Mg-Ag alloys.

The use of magnesium alloys as degradable metals for biomedical applications is a topic of ongoing research and the demand for multifunctional materials is increasing. Hence, binary Mg-Ag alloys were designed as implant materials to combine the favourable properties of magnesium with the well-known antibacterial property of silver. In this study, three Mg-Ag alloys, Mg2Ag, Mg4Ag and Mg6Ag that contain 1.87 %, 3.82 % and 6.00 % silver by weight, respectively, were cast and processed with solution (T4) and aging (T6) heat treatment. The metallurgical analysis and phase identification showed that all alloys contained Mg4Ag as the dominant ß phase. After heat treatment, the mechanical properties of all Mg-Ag alloys were significantly improved and the corrosion rate was also significantly reduced, due to presence of silver. Mg(OH)2 and MgO present the main magnesium corrosion products, while AgCl was found as the corresponding primary silver corrosion product. Immersion tests, under cell culture conditions, demonstrated that the silver content did not significantly shift the pH and magnesium ion release. In vitro tests, with both primary osteoblasts and cell lines (MG63, RAW 264.7), revealed that Mg-Ag alloys show negligible cytotoxicity and sound cytocompatibility. Antibacterial assays, performed in a dynamic bioreactor system, proved that the alloys reduce the viability of two common pathogenic bacteria, Staphylococcus aureus (DSMZ 20231) and Staphylococcus epidermidis (DSMZ 3269), and the results showed that the killing rate of the alloys against tested bacteria exceeded 90%. In summary, biodegradable Mg-Ag alloys are cytocompatible materials with adjustable mechanical and corrosion properties and show promising antibacterial activity, which indicates their potential as antibacterial biodegradable implant materials.

Cyclo-oxygenase-2 inhibitors or nonselective NSAIDs plus gastroprotective agents: what to prescribe in daily clinical practice?

BACKGROUND: Two strategies for prevention of upper gastrointestinal (UGI) events for nonselective nonsteroidal anti-inflammatory drug (nsNSAID) users are replacement of the nsNSAID by a cyclo-oxygenase-2-selective inhibitor (coxib) or co-prescription of a gastroprotective agent (GPA). AIM: To identify whether and in whom either of these strategies should be preferred in daily practice. METHODS: A nested case-control study was conducted using three European primary care databases. We selected a cohort including all naive nsNSAID+GPA (≥80% GPA adherence) and coxib users (without GPA use) aged ≥50 years. Cases with an UGI event (i.e. symptomatic UGI ulcer or bleeding) were matched to cohort members without an UGI event on age, sex and number of individual UGI risk factors (i.e. UGI event history, age ≥65 years, concomitant use of anticoagulants, antiplatelets, or glucocorticoids) and calendar time. Conditional logistic regression analysis was used to calculate odds ratios (ORs) with 95% CI, while adjusting for potential confounders. RESULTS: Within the NSAID cohort (n = 617,220), 398 UGI cases were identified. The risk of UGI events was equivalent for coxib and nsNSAID+GPA (≥80% adherence) users (OR: 1.02; 95%CI: 0.77-1.37). In concurrent glucocorticoid users, the risk of UGI events was significantly elevated for nsNSAID+GPA (≥80% adherence) compared with coxib users (OR: 9.01; 95%CI: 1.61-50.50). CONCLUSIONS: The risk of UGI events was similar in nsNSAID+GPA (≥80% adherence) and coxibs users. In patients concurrently using glucocorticoids, a significant increase in the risk of UGI events for nsNSAID+GPA users was observed and coxibs should be preferred.

Variable prenatal stress results in impairments of sustained attention and inhibitory response control in a 5-choice serial reaction time task in rats.

Rats repeatedly exposed to variable prenatal stress (PNS) exhibit schizophrenia-like behavioral signs such as social withdrawal, elevations in amphetamine-induced locomotor activity, deficits in sensory-motor gating, as well as impairments in memory-related task performance. However, to date there have been no studies designed to test the hypothesis that variable PNS would lead to disruptions in sustained attention and inhibitory response control (i.e., symptoms also commonly observed in schizophrenia and other neuropsychiatric disorders such as attention-deficit hyperactivity disorder). In the current study, the effects of variable PNS in rats were evaluated in fixed and variable stimulus duration (VSD) as well as variable intertrial interval (VITI) versions of a 5-choice serial reaction time task (5C-SRTT). In a separate series of experiments, the glutamate (N-methyl-d-aspartate [NMDA]) antagonist, MK-801 (0.025-0.05 mg/kg), and the norepinephrine reuptake inhibitor, atomoxetine (0.30-3.0mg/kg), were administered acutely to assess the sensitivity of PNS subjects to glutamatergic and noradrenergic manipulations. The results indicated that exposure to variable PNS significantly impaired accuracy in the VSD version of the 5C-SRTT and increased premature and timeout responses in the VITI version. In addition, both doses of MK-801 impaired accuracy, increased premature and timeout responses in PNS, but not control subjects. In contrast, atomoxetine decreased premature and timeout responses in both PNS and control subjects in the VITI version of the task and improved accuracy in the PNS subjects. The results suggest that exposure to variable PNS in rats results in impairments of sustained attention and inhibitory response control and that these deficits can be exacerbated by NMDA antagonism and improved by a norepinephrine uptake inhibitor. Collectively, these data further support the premise that variable PNS in rats is a valid model system for the study of neuropsychiatric disorders and their treatment.

The nicotine metabolite, cotinine, attenuates glutamate (NMDA) antagonist-related effects on the performance of the five choice serial reaction time task (5C-SRTT) in rats.

Cotinine, the most predominant metabolite of nicotine in mammalian species, has a pharmacological half-life that greatly exceeds its precursor. However, until recently, relatively few studies had been conducted to systematically characterize the behavioral pharmacology of cotinine. Our previous work indicated that cotinine improves prepulse inhibition of the auditory startle response in rats in pharmacological impairment models and that it improves working memory in non-human primates. Here we tested the hypothesis that cotinine improves sustained attention in rats and attenuates behavioral alterations induced by the glutamate (NMDA) antagonist MK-801. The effects of acute subcutaneous (dose range 0.03-10.0 mg/kg) and chronic oral administration (2.0 mg/kg/day in drinking water) of cotinine were evaluated in fixed and variable stimulus duration (VSD) as well as variable intertrial interval (VITI) versions of a five choice serial reaction time task (5C-SRTT). The results indicated only subtle effects of acute cotinine (administered alone) on performance of the 5C-SRTT (e.g., decreases in timeout responses). However, depending on dose, acute treatment with cotinine attenuated MK-801-related impairments in accuracy and elevations in timeout responses, and it increased the number of completed trials. Moreover, chronic cotinine attenuated MK-801-related impairments in accuracy and it reduced premature and timeout responses when the demands of the task were increased (i.e., by presenting VSDs or VITIs in addition to administering MK-801). These data suggest that cotinine may represent a prototype for compounds that have therapeutic potential for neuropsychiatric disorders (i.e., by improving sustained attention and decreasing impulsive and compulsive behaviors), especially those characterized by glutamate receptor alterations.

Biomimetic organic-inorganic nanocomposite coatings for titanium implants. In vitro and in vivo biological testing.

Recently described organic-inorganic nanocomposite coatings of the chemical composition: (PLL/PGA)(10)CaP[(PLL/PGA)(5)CaP](4) (coating A) and (PLL/PGA)(10)CaP[(PLL/PGA)(5)CaP](4)(PLL/PGA)(5) (coating B), applied to chemically etched titanium plates, have been tested by extensive cell culture tests and in vivo biological experiments, with uncoated titanium plates serving as controls. Before testing, coated samples were stored for extended periods of time (from 2 weeks to 8 months) under dry, sterile conditions. Cells of the cell-lines MC3T3-E1 and/or SAOS-2 were used for the following cell culture tests: initial adhesion (4 h) and proliferation (up to 21 days), cell activity (XTT test), morphology, synthesis of collagen type I and alkaline phosphatase activity (all incubation up to 21 days). In addition, coating B was tested against uncoated control in a validated in vivo pull-out model in rabbit tibia. The results of both in vitro and in vivo experiments show excellent biological properties of chemically etched titanium which are even surpassed by surfaces covered with coating B. Thus, after 8 weeks of healing the implants coated with B were significantly better attached to the cortical bone of rabbit thibiae than uncoated titanium controls with more than twice the force needed to detach coated implants. However, coating A (top crystal layer) had an adverse effect on both cell proliferation and activity, which is explained by morphological observations, showing inhibited spreading of the cells on its rough surfaces. The results also show the remarkable stability of the coatings when shelved under dry and sterile conditions.

Monitoring of laying capacity, immunoglobulin Y concentration, and antibody titer development in chickens immunized with ricin and botulinum toxins over a two-year period.

One of the key benefits in using chickens for immunization is the high yield of antibodies obtainable. It is known that egg production decreases over time, while animal maintenance costs remain stable. It would, however, be desirable to keep hens as long as possible to obtain maximal amounts of antibodies. To identify a suitable length of time that animals can be kept and to optimize the cost:yield ratio, we monitored the number of eggs laid, the total amount of chicken IgY, and the specific antibody titer from individually prepared eggs over a 2-yr period. The plant toxin ricin and the Clostridium botulinum neurotoxins type A and B were used to immunize 4 chickens. The number of eggs laid in 2 yr was approximately 600 per hen (about 80% of the maximum egg number), yielding about 20 to 40 g of total IgY per hen. A stable antibody titer of 1:100,000 to 1:1,000,000, as measured by ELISA, was obtained following up to 11 injections of 10 to 20 microg of immobilized native toxin. Laying capacities were found to decrease, on average, from 7 eggs/wk at the point of first immunization to 2 eggs/wk after more than 2 yr. In parallel, the yield of total and specific IgY increased over time, so that the antibody recovery remained high, even after prolonged immunization times. Using purified IgY preparations, classical immunological assays such as ELISA and Western blotting were performed. Furthermore, the IgY showed neutralizing capacity when used to block the functional activity of the toxins both in vitro and in vivo. Analysis of the total IgY content over time demonstrated a complex biological oscillation (and the antigen-specific titer), with a shorter time period of around 7 d (circaseptan rhythm). In summary, we successfully immunized chickens with ricin and botulinum neurotoxins and monitored laying capacity, IgY concentration, and specific antibody titer over an extended period of 2 yr.

Evaluación de la especificidad de anticuerpos policlonales aviarios y mamíferos anti-Factor Precoz de Preñez porcino / Specificity evaluation of polyclonal avian and mammalian anti-porcine early pregnancy factor antibodies

El EPF es una proteína con propiedades inmunomoduladoras y reguladoras del crecimiento, presente en el suero de los animales durante la gestación. Es un marcador temprano de viabilidad embrionaria durante la fase peri-implantacional. La obtención de anticuerpos(Acs) anti-EPF nos permitiría contar con una valiosa herramienta para investigar las funciones biológicas de este factor. No se ha logrado obtener Acs monoclonales anti-EPF debido a su función como factor de crecimiento autócrino para los hibridomas. La distancia filogenéticaque existe entre las aves y los mamíferos resulta potencialmente ventajosa para la producción de un alto porcentaje de Acs específicos contra antígenos mamíferos. El objetivo de este trabajo fue laobtención de Acs policlonales anti-EPF porcino aviarios y de mamífero, comparando la producción y la especificidad de cada lote de anticuerpos. Se inmunizaron gallinas y conejos con un péptido sintéticode EPF o con la banda de 29 kDa aislada por SDS-PAGE proveniente de suero de una cerda de 7 días de gestación. Las IgY aviarias anti-EPF se purificaron por el método de precipitación con ácido caprílico y polietilenglicol 6000, y las IgG anti-EPF de conejo por precipitación salina con sulfato de amonio. El rendimiento proteico fue evaluado por Bradford y la especificidad de los Acs por “Dot Blot” eInmunoblot. El rendimiento proteico fue satisfactorio en todos los lotes de Acs. El lote de Acs obtenidos en conejos inmunizados con el péptido sintético presentó especificidad satisfactoria. Los lotes obtenidosen conejos y gallinas inmunizadas con la banda de SDS-PAGE de 29 kDa presentaron baja especificidad, mientras que el lote obtenido en gallinas inmunizadas con el péptido sintético presentó nula especificidad. El péptido sintético de EPF indujo la producción deAcs más específicos en conejos, pero la banda de 29 kDa de SDS-PAGE no es adecuada para obtener Acs específicos contra este factor dado que además del EPF reconoce otras proteínas presentes en el suero

Early Pregnancy Factor (EPF) is a secreted protein with known functions as immunomodulator and growth factor, released very early in mammalian gestation. EPF represents an early marker of gestationand a very useful tool to supervise embryonic viability during the peri-implantational period. Obtaining anti-EPF antibodies (Abs) would mean having a valuable tool to investigate the biological functions ofthis factor, but it has failed so far due to EPF´s function as an autocrine growth factor for hibridomas. The phylogenetic distance between birds and mammals is potentially advantageous for the efficientproduction of specific Abs against mammalian antigens. Thus, the objective of this work was to obtain avian and mammalian polyclonal anti-porcine EPF Abs and to evaluate the protein yield and the specificity of each batch of antibodies. Hens and rabbits were immunizedwith a synthetic EPF peptide, or with EPF isolated and purified from porcine serum of 7 days of gestation by SDS-PAGE (29 kDa band). IgY anti-EPF antibodies from hens were purified by combined caprylic acid and polyethylene glycol 6000 precipitation, and rabbitanti-EPF IgG by sulphate ammonium precipitation. Protein yield was evaluated by Bradford, and Ab specificity by Dot Blot and Immunoblot. The protein yield was satisfactory in all batches of Abs. The specificity of Abs obtained from rabbits immunized with the syntheticEPF peptide was satisfactory. Batches of immunoglobulins obtained from rabbits and hens immunized with the SDS-PAGE 29 kDa band displayed low specificity, whereas the batch obtained from hens immunized with the synthetic peptide presented null specificity. The synthetic peptide induced the production of more specific Abs whenthey were raised in rabbits. In contrast, the SDS-PAGE 29 kDa band is not useful to obtain specific Abs against this factor, since in addition to EPF it recognizes other proteins present in the serum

Liver transplantation for hepatitis B in the United States.

AIM: To evaluate the impact of hepatitis B virus (HBV) on US health care system, we reviewed the Organ Procurement and Transplantation (OPTN, formerly UNOS) HBV database. METHOD: We reviewed records of liver transplantations (LTx) performed in the United States listed for the diagnoses of HBV between 1993 and mid-October 2004. Both acute as well as chronic cases were included. Coinfection with hepatitis C virus was excluded from study. The specific states selected for review were chosen from those areas that are receiving large numbers of new immigrants from high HBV endemic areas (ie, Texas, Pennsylvania, California, New York, and Florida). One-, 3-, and 5-year patient survival rates for both cadaveric and living related donors were analyzed. Survival rates were obtained from OPTN database as Kaplan-Meyer survival test. RESULTS: Between 1993 and mid-October 2004, 53,312 LTx had been performed nationwide. Of these, 2314 (4.34%) were performed for the diagnosis of HBV; 1816 cases (78%) were due to chronic HBV infection (45 of them were living donor LTx) and 498 cases (22%) were due to HBV-induced acute liver failure (seven of them were living donor LTx). Three- and 5-year survival rates of chronic HBV-related LTx patients were better than acute HBV-related and overall LTx patients. CONCLUSION: HBV is generally considered to have a minor health significance by many community gastroenterologists. With growing immigration from overseas, it may eventually have a higher impact on LTx. Therefore, it is crucial to further educate gastroenterologists and primary care physicians caring for this specific group of patients.

[Double blind placebo controlled cow's milk provocation for the diagnosis of cow's milk allergy in infants and children]. / Dubbelblinde placebogecontroleerde koemelkprovocatie voor de diagnostiek van koemelkallergie bij zuigelingen en kinderen.

OBJECTIVE: To test a protocol for a double-blind placebo-controlled cow's milk provocation for the diagnosis of acute allergic reactions to milk in an outpatient setting. DESIGN: Prospective, descriptive. METHOD: During the period from June 1, 1999 to February 28, 2001 the protocol was tested on all infants and children who were referred to the Paediatric outpatient clinic of the University Medical Centre on Utrecht with symptoms indicative of cow's milk allergy. The protocol comprised of a phased administration of two test meals, one with a true feed and one with placebo, during the course of one day. In case of allergic symptoms the test was discontinued and the code was broken. A diagnosis of 'cow's milk allergy' was made if the symptoms appeared during the provocation with true feeding. RESULTS: The test group (n = 154) consisted of 85 boys and 69 girls with ages ranging from 0.25 to 14 years (median 1.5). Acute type reactions to cow's milk occurred in 21 of the children who underwent the provocation. These reactions mainly consisted of cutaneous symptoms (erythema and urticaria). In none of these cases the symptoms were severe enough to require a prolonged stay in the hospital. There were no reactions on placebo meals nor acute reactions during the reintroduction of milk at home. CONCLUSION: It is possible to perform double-blind placebo-controlled provocations routinely in the diagnostic work-up of children with a suspicion of cow's milk allergy.

Role of 5-HT1A receptors in the control of food intake in obese Zucker rats of different ages.

The present study describes the role of 5-HT1A receptors in the serotonergic control of food intake in obese Zucker rats of different ages. In addition, serotonin (5-HT) and cholecystokinin (CCK) content and 5-HT turnover were determined in various brain regions. The 5-HT1A receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT; 100 microg/kg) stimulated food intake in 3-month-old lean control rats but inhibited feeding in obese Zucker rats (300 microg/kg). This pattern remained the same in 6-month-old rats. At 10 months of age, 8-OH-DPAT lost its inhibitory activity in the obese rats but still stimulated feeding in lean controls (300 microg/kg). 5-HT levels were higher in the hypothalamus and in the frontal and parietal cortices of 3-month-old obese Zucker rats and were associated with a lower cortical turnover. In the parietal cortex and the hypothalamus of 6-month-old rats, 5-HT levels were still higher, linked with a lower hypothalamic turnover. No differences were observed in 10-month-old rats. CCK content was not different between obese Zucker rats and lean rats. The persistently different feeding responses to 8-OH-DPAT in obese Zucker rats and lean controls may be related to changes in brain 5-HT metabolism in the obese Zucker rats.

Human haemoclassification by use of specific yolk antibodies obtained after immunisation of chickens against human blood group antigens.

Polyclonal antibodies, widely used in research and diagnostics, are conventionally isolated from the blood of immunised mammals, especially rabbits. The fact that antibodies can also be detected in the yolk of eggs laid by immunised hens, led to the development of yolk antibody technology (IgY-technology) as an alternative method that is less stressful to animals. This technology has become a worthwhile alternative to the blood-dependent techniques. Furthermore, because of the phylogenetic distance between birds and mammals, avian antigens have a very specific immune response to highly conserved antigens of mammals, such as human erythrocyte antigens. To evaluate the humoral immune response of hens immunised with human red erythrocyte antigens, 22 White Leghorn hens were kept in cages and immunised with total red blood cells or stroma of the human rhesus positive (Rh+) system (D antigen) by weekly intramuscular and intravenous injections, without the use of an adjuvant. The haemagglutination assay was used to evaluate the dynamics of the production of IgY antibodies against human erythrocyte antigens, and single radial immunodiffusion was used to evaluate the amount of total IgY in de-lipidated supernatants from egg yolk. The highest titres were observed four weeks after the first immunisation, and these remained stable for up to seven weeks for the intravenous route. Positive reactivity against human erythrocyte antigens A, B and O was demonstrated in de-lipidated supernatants from the egg yolks of immunised hens. The strongest reaction was observed against blood group O Rh+ (O+).

Differences in antigen-specific T-cell responses between infants with atopic dermatitis with and without cow's milk allergy: relevance of TH2 cytokines.

BACKGROUND: Cow's milk is the most important food antigen in infancy and may lead to acute cutaneous symptoms and atopic dermatitis (AD). The role of circulating allergen-specific T cells in the pathogenesis of food-allergic skin symptoms is still under investigation. OBJECTIVE: This study was designed to analyze the cow's milk protein (CMP)-specific T-cell response at the clonal level in infants with AD and cow's milk allergy (CMA) in comparison with infants with AD without CMA. METHODS: We used an antigen-specific culturing system with autologous B cells as antigen-presenting cells to establish CMP-specific T-cell clones derived from PBMCs in infants with AD. T-cell reactivity, measured by using a lymphocyte stimulation test, and cytokine production, measured by using ELISA, was compared between infants with AD with and without CMA. RESULTS: Both infants with and without allergy to cow's milk had a CMP-specific T helper cell response directed against the major proteins in milk. Analysis of antigen-specific cytokine production showed that this response was T(H)2 skewed in infants with CMA, with production of high levels of IL-4, IL-5, and IL-13. In contrast, infants without CMA had a T(H)1-skewed response, with high levels of IFN-gamma and low levels of IL-4, IL-5, and IL-13. CONCLUSION: These data confirm for the first time at the clonal level that food allergy in infants with AD is associated with production of T(H)2 cytokines by circulating antigen-specific CD4(+) T cells, whereas tolerance to food antigens is associated with low levels of these cytokines. This suggests a key role for the T helper cell-derived T(H)2 cytokines in food allergy-related skin symptoms.

Replacement of fetal calf serum in cell cultures by an egg yolk factor with cholecystokinin/gastrin-like immunoreactivity.

The in vitro culture of various cell types is an important scientific tool and is becoming increasingly acceptable as a viable alternative to animal experiments. Fetal calf serum (FCS) is a supplement used in many cell culture media, and provides cells with growth factors and cytokines necessary for successful culture. In view of the animal welfare issues surrounding the production of FCS, an alternative agent allowing the replacement or reduction in the use of FCS is desirable. A yolk extract factor (EYF-X) obtained from chicken eggs is described, which facilitates the in vitro culture of a variety of cell types. When the extract was added to a culture medium used for in vitro fertilisation, the number of successful fertilisations was significantly increased. In a further in vitro model (permanent neuronal cell line N2A), the yolk extract significantly stimulated cell proliferation as well as the growth of cell processes. A set of specific antibodies against different parts of the prepro-cholecystokinin reacted with the extract. The intensity of the reaction depends on the age of the egg (time after the laying date). Analysis by gel chromatography recorded a main protein fraction with an apparent molecular mass of 20-30kDa. This fraction was labelled by Western blot with an antibody with specificity against CCK-octapeptide. These findings suggest that the yolk factor may be a CCK/gastrin-like molecule. Since CCK/gastrin-like molecules have also been detected in the spermatozoa of mammals, the influence on in vitro fertilisation could be explained by the yolk factor replacing the endogenous CCK/gastrin-like molecule destroyed in sperm freezing. The results of this study suggest that it might be possible to replace FCS with EYF-X. The application of the yolk factor to a broad spectrum of cell types remains to be investigated.

Helicobacter pylori infection in sickle cell disease.

Abdominal pain is a common presenting symptom in adults with sickle cell disease (SCD). One case of Helicobacter pylori gastritis has been reported in a child with sickle cell anemia. H. pylori-induced peptic ulcer disease (PUD) has not previously been reported in adults with SCD. We report eight cases of H. pylori infection in adult sickle cell patients presenting with acute or recurrent abdominal pain and/or gastrointestinal bleeding. In all cases, H. pylori serology (IgG) was positive, and three patients had gastric or duodenal ulcer by endoscopic examination. All patients responded to H. pylori treatment with complete resolution of symptoms by 4 weeks. The prevalence of H. pylori infection in SCD is unknown, but patients may be at increased risk for H. pylori-induced PUD and complications due to pre-existing anemia, increased nonsteroidal anti-inflammatory drug use, and alloimmunization which may delay necessary transfusion. It is important that the differential diagnosis of abdominal pain in adults with SCD include nonsickle cell-related disorders such as PUD. When confirmed, a definitive etiology of PUD must be determined so that appropriate treatment strategies can be initiated promptly and excess morbidity avoided.

Electron microscopy and subunit-subunit interaction studies reveal a first architecture of COP9 signalosome.

The COP9 signalosome is involved in signal transduction, whereas the 26 S proteasome lid is a regulatory subcomplex of the 26 S proteasome responsible for degradation of ubiquitinated proteins. COP9 signalosome and lid possess significant sequence homologies among their eight core subunits and are likely derived from a common ancestor. Surprisingly, from our two-dimensional electron microscopy data, a common architectural plan for the two complexes could not be deduced. None-the-less, the two particles have structural features in common. Both COP9 signalosome and lid lack any symmetry in subunit arrangement and exhibit a central groove, possibly qualified for scaffolding functions.Filter-binding assays with recombinant COP9 signalosome components revealed a multitude of subunit-subunit interactions, supporting the asymmetrical appearance of the complex in electron microscopy. On the basis of two-dimensional images and subunit interaction studies, a first architectural model of COP9 signalosome was created. The fact that four distinct classes of particle views were identified and that only 50 % of the selected particles could be classified indicates a high degree of heterogeneity in electron microscopic images. Different orientations with respect to the viewing axis and conformational variety, presumably due to different grades of phosphorylation, are possible reasons for the heterogeneous appearance of the complex. Our biochemical data show that recombinant COP9 signalosome subunits 2 and 7 are phosphorylated by the associated kinase activity. The modification of COP9 signalosome subunit 2 might be essential for c-Jun phosphorylation. Dephosphorylation does not inactivate the associated kinase activity. Although substrate phosphorylation by COP9 signalosome is significantly decreased by lambda protein phosphatase treatment, "autophosphorylation" is increased.