Hepatitis C virus point-of-care microelimination approach in a vulnerable population in the South of Spain

Background

Since the introduction of direct-acting antivirals, thousands of chronic hepatitis C patients have been successfully treated. However, vulnerable populations have a higher prevalence of hepatitis C virus (HCV) infection and face barriers that impede their access to antivirals. We carried out an HCV microelimination program focused on vulnerable population groups in Malaga.

Methods

People in drug addiction treatment centers and homeless shelters in Malaga who participated in the program between October 2020 and October 2021 were included. After providing participants with educational information on HCV, a dry drop test (DDT) was used to collect blood for subsequent screening for HCV infection. The participants who were diagnosed with HCV infection were scheduled for comprehensive healthcare assessments, including blood tests, ultrasonography, elastography, and the prescription of antivirals, all conducted in a single hospital visit. Sustained viral response (SVR) was analysed 12 weeks after end of treatment.

Results

Of the 417 persons invited to participate, 271 (65%) agreed to participate in the program. These participants were screened for HCV infection and 28 of them were diagnosed with HCV infection (10%). These hepatitis C-infected patients had a mean age of 53 ± 9 years; 86% were males and 93% were or had been drug users. Among 23 patients with HCV infection, HCV genotype 1a predominated (74%). Medical exams showed that 19% (4/21) had advanced fibrosis (F3-4), and 5% (1/21) had portal hypertension. Finally, 23 infected patients received treatment with glecaprevir/pibrentasvir or sofosbuvir/velpatasvir and SVR was confirmed in 22 patients (96%).

Conclusions

Drug users and homeless people have a higher prevalence of HCV infection than the general population. The microelimination program with educational activity and screening tools achieved a high participation rate, easy healthcare access, and a high rate of SVR despite the SARS-CoV-2 pandemic.

Importance of twitching and surface-associated motility in the virulence of Acinetobacter baumannii

Acinetobacter baumannii is a pathogen of increasing clinical importance worldwide, especially given its ability to readily acquire resistance determinants. Motile strains of this bacterium can move by either or both of two types of motility: (i) twitching, driven by type IV pili, and (ii) surface-associated motility, an appendage-independent form of movement. A. baumannii strain MAR002 possesses both twitching and surface-associated motility. In this study, we isolated spontaneous rifampin-resistant mutants of strain MAR002 in which point mutations in the rpoB gene were identified that resulted in an altered motility pattern. Transcriptomic analysis of mutants lacking twitching, surface-associated motility, or both led to the identification of deregulated genes within each motility phenotype, based on their level of expression and their biological function. Investigations of the corresponding knockout mutants revealed several genes involved in the motility of A. baumannii strain MAR002, including two involved in twitching (encoding a minor pilin subunit and an RND [resistance nodulation division] component), one in surface-associated motility (encoding an amino acid permease), and eight in both (encoding RND and ABC components, the energy transducer TonB, the porin OprD, the T6SS component TagF, an IclR transcriptional regulator, a PQQ-dependent sugar dehydrogenase, and a putative pectate lyase). Virulence assays showed the reduced pathogenicity of mutants with impairments in both types of motility or in surface-associated motility alone. By contrast, the virulence of twitching-affected mutants was not affected. These results shed light on the key role of surface-associated motility and the limited role of twitching in the pathogenicity of A. baumannii.

Evaluation of neurotrophic factors and education level as predictors of cognitive decline in alcohol use disorder

Cognitive reserve (CR) is the capability of an individual to cope with a brain pathology through compensatory mechanisms developed through cognitive stimulation by mental and physical activity. Recently, it has been suggested that CR has a protective role against the initiation of substance use, substance consumption patterns and cognitive decline and can improve responses to treatment. However, CR has never been linked to cognitive function and neurotrophic factors in the context of alcohol consumption. The present cross-sectional study aims to evaluate the association between CR (evaluated by educational level), cognitive impairment (assessed using a frontal and memory loss assessment battery) and circulating levels of brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3) in patients with alcohol use disorder (AUD). Our results indicated that lower educational levels were accompanied by earlier onset of alcohol consumption and earlier development of alcohol dependence, as well as impaired frontal cognitive function. They also suggest that CR, NT-3 and BDNF may act as compensatory mechanisms for cognitive decline in the early stages of AUD, but not in later phases. These parameters allow the identification of patients with AUD who are at risk of cognitive deterioration and the implementation of personalized interventions to preserve cognitive function.

Analysis of Both Lipid Metabolism and Endocannabinoid Signaling Reveals a New Role for Hypothalamic Astrocytes in Maternal Caloric Restriction-Induced Perinatal Programming

Maternal malnutrition in critical periods of development increases the risk of developing short- and long-term diseases in the offspring. The alterations induced by this nutritional programming in the hypothalamus of the offspring are of special relevance due to its role in energy homeostasis, especially in the endocannabinoid system (ECS), which is involved in metabolic functions. Since astrocytes are essential for neuronal energy efficiency and are implicated in brain endocannabinoid signaling, here we have used a rat model to investigate whether a moderate caloric restriction (R) spanning from two weeks prior to the start of gestation to its end induced changes in offspring hypothalamic (a) ECS, (b) lipid metabolism (LM) and/or (c) hypothalamic astrocytes. Monitorization was performed by analyzing both the gene and protein expression of proteins involved in LM and ECS signaling. Offspring born from caloric-restricted mothers presented hypothalamic alterations in both the main enzymes involved in LM and endocannabinoids synthesis/degradation. Furthermore, most of these changes were similar to those observed in hypothalamic offspring astrocytes in culture. In conclusion, a maternal low caloric intake altered LM and ECS in both the hypothalamus and its astrocytes, pointing to these glial cells as responsible for a large part of the alterations seen in the total hypothalamus and suggesting a high degree of involvement of astrocytes in nutritional programming.

Direct interaction between RecA and a CheW-like protein is required for surface-associated motility, chemotaxis and the full virulence of Acinetobacter baumannii strain ATCC 17978

Acinetobacter baumannii is a nosocomial pathogen that causes multi-drug resistant infections mainly in immunocompromised patients. Although this gram-negative species lacks flagella, it is able to move over wet surfaces through a not well characterized type of movement known as surface-associated motility. In this study we demonstrate through the inactivation of the A1S_2813 gene (coding a CheW-like protein) and recA (coding a DNA damage repair and recombination protein) that both genes are involved in the surface-associated motility and chemotaxis of A. baumannii ATCC 17978 strain. In addition, we also point out that the lack of either RecA or CheW-like proteins reduces its virulence in the Caenorhabditis elegans and the Galleria mellonella animal models. Furthermore, we show through co-immunoprecipitation assays that the CheW-like protein and RecA interact and that this interaction is abolished by the introduction of the mutation S97A in one of the domains of CheW-like protein that is structurally conserved in Salmonella enterica and necessary for the RecA-CheW interaction in this bacterial species. Finally, we show that the replacement of the wild-type CheW-like protein by that presenting the S97A mutation impairs surface-associated motility, chemotaxis and virulence of A. baumannii strain ATCC 17978.

Sex-specific behavioral and neurogenic responses to cocaine in mice lacking and blocking dopamine D1 or dopamine D2 receptors

Adult neurogenesis in rodents is modulated by dopaminergic signaling and inhibited by cocaine. However, the sex-specific role of dopamine D1 and D2 receptors (D1R, D2R) in the deleterious effect of cocaine on adult neurogenesis has not been described yet. Here, we explored sex differences in (a) cell proliferation (5'-bromo-2'-deoxyuridine [BrdU]), (b) neural precursor (nestin), (c) neuronal phenotype (BrdU/β3-tubulin), and (d) neuronal maturity (NeuN) in the subventricular zone (SVZ) of the lateral ventricles and striatum of mice with genetic deletion (D1^-/- , D2^-/- ) or pharmacological blockage (SCH23390: 0.1 mg/kg/day/5 days; Raclopride: 0.3 mg/kg/day/5 days) of D1R and D2R, and treated (10 mg/kg/day/5 days) and then challenged (5 mg/kg, 48 hr later) with cocaine. Results indicated that hyperactivity responses to cocaine were absent in D1^-/- mice and reduced in SCH23390-treated mice. Activity responses to cocaine were reduced in D2^-/- males, but absent in D2^-/- females and increased in Raclopride-treated females. D1R deletion blocked the deleterious effect of cocaine on SVZ cell proliferation in males. Cocaine-exposed D1^-/- males also had reduced neuronal phenotype of SVZ newborn cells and increased striatal neuronal maturity. D2^-/- mice had lower proliferative and neural precursor responses. Cocaine in D2^-/- females or coadministered with Raclopride in wild-type females improved SVZ cell proliferation, an effect that positively correlated with plasma brain-derived neurotrophic factor (BDNF) concentrations. In conclusion, the sex-specific D1R and D2R signaling on SVZ cell proliferation, neural progenitor and neuronal maturity is differentially perturbed by cocaine, and BDNF may be required to link D2R to neuroplasticity in cocaine addiction in females.

COLR Acinetobacter baumannii sRNA Signatures: Computational Comparative Identification and Biological Targets

Multidrug-Resistant (MDR) and Extensively Drug Resistant (XDR) Acinetobacter baumannii (Ab) represent a serious cause of healthcare-associated infections worldwide. Currently, the available treatment options are very restricted and colistin-based therapies are last-line treatments of these infections, even though colistin resistant (COL^R) Ab have rarely been isolated yet. In bacteria, small non-coding RNAs (sRNAs) have been implicated in regulatory pathways of different biological functions, however, no knowledge exists about the sRNA role on the biological adaptation in COL^RAb. Our study investigated two Italian XDR isogenic colistin-susceptible/resistant (COL^S/R) Ab strain-pairs to discover new sRNA signatures. Comparative sRNA transcriptome (sRNAome) analyses were carried out by Illumina RNA-seq using both a Tru-Seq and a Short Insert library, whilst Ab ATCC 17978 and ACICU Reference Genome assembly, mapping, annotation and statistically significant differential expression (q-value ≤ 0.01) of the raw reads were performed by the Rockhopper tool. A computational filtering, sorting only similarly statistically significant differentially expressed (DE) sRNAs mapping on the same gene in both COL^RAb isolates was conducted. COL^R vs. COL^S sRNAome, analyzed integrating the DE sRNAs obtained from the two different libraries, revealed some statistically significant DE sRNAs in COL^RAb. In detail, we found: (i) two different under-expressed cis-acting sRNAs (AbsRNA₁ and AbsRNA₂) mapping in antisense orientation the 16S rRNA gene A1S_r01, (ii) one under-expressed cis-acting sRNA (AbsRNA₃) targeting the A1S_2505 gene (hypothetical protein), (iii) one under-expressed microRNA-size small RNA fragment (AbsRNA₄) and its pre-microAbsRNA₄ targeting the A1S_0501 gene (hypothetical protein), (iv) as well as an over-expressed microRNA-size small RNA fragment (AbsRNA₅) and its pre-microAbsRNA₅ targeting the A1S_3097 gene (signal peptide). Custom TaqMan^® probe-based real-time qPCRs validated the expression pattern of the selected sRNA candidates shown by RNA-seq. Furthermore, analysis on sRNA ΔA1S_r01, ΔA1S_2505 as well as the over-expressed A1S_3097 mutants revealed no effects on colistin resistance. Our study, for the first time, found the sRNAome signatures of clinical COL^RAb with a computational prediction of their targets related to protein synthesis, host-microbe interaction and other different biological functions, including biofilm production, cell-cycle control, virulence, and antibiotic-resistance.

Free energy profiles for two ubiquitous damaging agents: methylation and hydroxylation of guanine in B-DNA

DNA methylation and hydroxylation are two ubiquitous reactions in DNA damage induction, yet insights are scarce concerning the free energy of activation within B-DNA. We resort to multiscale simulations to investigate the attack of a hydroxyl radical and of the primary diazonium onto a guanine embedded in a solvated dodecamer. Reaction free energy profiles characterize two strongly exergonic processes, yet allow unprecedented quantification of the barrier towards this damage reaction, not higher than 6 kcal mol^-1 and sometimes inexistent, and of the exergonicities. In the case of the [G(C8)-OH]˙ intermediate, we challenge the functional dependence of such simulations: recently-proposed functionals, such as M06-2X and LC-BLYP, agree on a ∼4 kcal mol^-1 barrier, whereas the hybrid GGA B3LYP functional predicts a barrier-less pathway. In the long term, multiscale approaches can help build up a unified panorama of DNA lesion induction. These results stress the importance of DFT/MM-MD simulations involving new functionals towards the sound modelling of biomolecule damage even in the ground state.

Molecular Interaction and Cellular Location of RecA and CheW Proteins in Salmonella enterica during SOS Response and Their Implication in Swarming

In addition to its role in DNA damage repair and recombination, the RecA protein, through its interaction with CheW, is involved in swarming motility, a form of flagella-dependent movement across surfaces. In order to better understand how SOS response modulates swarming, in this work the location of RecA and CheW proteins within the swarming cells has been studied by using super-resolution microscopy. Further, and after in silico docking studies, the specific RecA and CheW regions associated with the RecA-CheW interaction have also been confirmed by site-directed mutagenesis and immunoprecipitation techniques. Our results point out that the CheW distribution changes, from the cell poles to foci distributed in a helical pattern along the cell axis when SOS response is activated or RecA protein is overexpressed. In this situation, the CheW presents the same subcellular location as that of RecA, pointing out that the previously described RecA storage structures may be modulators of swarming motility. Data reported herein not only confirmed that the RecA-CheW pair is essential for swarming motility but it is directly involved in the CheW distribution change associated to SOS response activation. A model explaining not only the mechanism by which DNA damage modulates swarming but also how both the lack and the excess of RecA protein impair this motility is proposed.

The transcriptomic response of Acinetobacter baumannii to colistin and doripenem alone and in combination in an in vitro pharmacokinetics/pharmacodynamics model

OBJECTIVES

Colistin remains a last-line treatment for MDR Acinetobacter baumannii and combined use of colistin and carbapenems has shown synergistic effects against MDR strains. In order to understand the bacterial responses to these antibiotics, we analysed the transcriptome of A. baumannii following exposure to each.

METHODS

RNA sequencing was employed to determine changes in the transcriptome following treatment with colistin and doripenem, both alone and in combination, using an in vitro pharmacokinetics (PK)/pharmacodynamics model to mimic the PK of both antibiotics in patients.

RESULTS

After treatment with colistin (continuous infusion at 2 mg/L), >400 differentially regulated genes were identified, including many associated with outer membrane biogenesis, fatty acid metabolism and phospholipid trafficking. No genes were differentially expressed following treatment with doripenem (Cmax 25 mg/L, t1/2 1.5 h) for 15 min, but 45 genes were identified as differentially expressed after 1 h of growth under this condition. Treatment of A. baumannii with both colistin and doripenem together for 1 h resulted in >450 genes being identified as differentially expressed. More than 70% of these gene expression changes were also observed following colistin treatment alone.

CONCLUSIONS

These data suggest that colistin causes gross damage to the outer membrane, facilitates lipid exchange between the inner and outer membrane and alters the normal asymmetric outer membrane composition. The transcriptional response to colistin was highly similar to that observed for an LPS-deficient strain, indicating that many of the observed changes are responses to outer membrane instability resulting from LPS loss.

The catalytic mechanism of carboxylesterases: a computational study

The catalytic mechanism of carboxylesterases (CEs, EC 3.1.1.1) is explored by computational means. CEs hydrolyze ester, amide, and carbamate bonds found in xenobiotics and endobiotics. They can also perform transesterification, a reaction important, for instance, in cholesterol homeostasis. The catalytic mechanisms with three different substrates (ester, thioester, and amide) have been established at the M06-2X/6-311++G**//B3LYP/6-31G* level of theory. It was found that the reactions proceed through a mechanism involving four steps instead of two as is generally proposed: (i) nucleophilic attack of serine to the substrate, forming the first tetrahedral intermediate, (ii) formation of the acyl-enzyme complex concomitant with the release of the alcohol product, (iii) nucleophilic attack of a water or alcohol molecule forming the second tetrahedral intermediate, and (iv) the release of the second product of the reaction. The results agree very well with the available experimental data and show that the hydrolytic and the transesterification reactions are competitive processes when the substrate is an ester. In all the other studied substrates (thioester or amide), the hydrolytic and transesterification process are less favorable and some of them might not even take place under in vivo conditions.

Regression activity that is naturally present in vitreous becomes ineffective as patients develop proliferative diabetic retinopathy

AIMS/HYPOTHESIS

The realisation that targeting agents in the vitreous is an effective approach to treating patients with diabetic retinopathy (DR) has increased awareness that changes in the composition/bioactivity of the vitreous is a contributor to the pathogenesis of DR. The overall goal of this study was to test the hypothesis that the vitreous has regression activity, and that lysophosphatidic acid (LPA) contributes to such activity. LPA is a bioactive phospholipid present in many biological fluids, and has been recently appreciated for its ability to promote regression of blood vessels.

METHODS

Vitreous-mediated regression was monitored on tubes organised from primary retinal endothelial cells or neovessels that sprouted from retinal explants. LPA was quantified radioenzymatically.

RESULTS

Bovine and human vitreous promoted regression of retinal explant vessels and of tubes organised from primary retinal endothelial cells. LPA was a substantial component of this regression activity. Comparing the regression activities of vitreous from patients with different stages of DR revealed that, as patients developed proliferative diabetic retinopathy (PDR), vitreous lost its ability to promote regression, even though the amount of LPA did not change. The underlying mechanism was a PDR-vitreous-mediated insensitivity to LPA, which could be overcome pharmacologically.

CONCLUSIONS/INTERPRETATION

Our findings suggest that a decline in the responsiveness to regression factors such as LPA, which are naturally present in the vitreous, contributes to the pathogenesis of PDR.

Exploring bacterial diversity in hospital environments by GS-FLX Titanium pyrosequencing

Understanding microbial populations in hospital environments is crucial for improving human health. Hospital-acquired infections are an increasing problem in intensive care units (ICU). In this work we present an exploration of bacterial diversity at inanimate surfaces of the ICU wards of the University Hospital A Coruña (Spain), as an example of confined hospital environment subjected to selective pressure, taking the entrance hall of the hospital, an open and crowded environment, as reference. Surface swab samples were collected from both locations and recovered DNA used as template to amplify a hypervariable region of the bacterial 16S rRNA gene. Sequencing of the amplicons was performed at the Roche 454 Sequencing Center using GS-FLX Titanium procedures. Reads were pre-processed and clustered into OTUs (operational taxonomic units), which were further classified. A total of 16 canonical bacterial phyla were detected in both locations. Members of the phyla Firmicutes (mainly Staphylococcus and Streptococcus) and Actinobacteria (mainly Micrococcaceae, Corynebacteriaceae and Brevibacteriaceae) were over-represented in the ICU with respect to the Hall. The phyllum Proteobacteria was also well represented in the ICU, mainly by members of the families Enterobacteriaceae, Methylobacteriaceae and Sphingomonadaceae. In the Hall sample, the phyla Proteobacteria, Bacteroidetes, Deinococcus-Thermus and Cyanobacteria were over-represented with respect to the ICU. Over-representation of Proteobacteria was mainly due to the high abundance of Enterobacteriaceae members. The presented results demonstrate that bacterial diversity differs at the ICU and entrance hall locations. Reduced diversity detected at ICU, relative to the entrance hall, can be explained by its confined character and by the existence of antimicrobial selective pressure. This is the first study using deep sequencing techniques made in hospital wards showing substantial hospital microbial diversity.

An overview of a regional meteorology warning system

Abstract. In this work we present a regional meteorology warning system, particularly the operational weather warning system used by the Basque Meteorology Agency (Euskalmet) for Basque Country. System considers different meteorological phenomena capable of generate warnings, and is based on combined thresholds criteria depending on particular weather event and area of territory where is applied. In this work we describe the most significant aspects related with the warning event definition and the warning bulletin. Conclusions from comparison with the former system (prior to 2009) and feedback from different users are presented.

Deciphering the function of the outer membrane protein OprD homologue of Acinetobacter baumannii

The increasing number of carbapenem-resistant Acinetobacter baumannii isolates is a major cause for concern which restricts therapeutic options to treat severe infections caused by this emerging pathogen. To identify the molecular mechanisms involved in carbapenem resistance, we studied the contribution of an outer membrane protein homologue of the Pseudomonas aeruginosa OprD porin. Suspected to be the preferred pathway of carbapenems in A. baumannii, the oprD homologue gene was inactivated in strain ATCC 17978. Comparison of wild-type and mutant strains did not confirm the expected increased resistance to any antibiotic tested. OprD homologue sequence analysis revealed that this protein actually belongs to an OprD subgroup but is closer to the P. aeruginosa OprQ protein, with which it could share some functions, e.g., allowing bacterial survival under low-iron or -magnesium growth conditions or under poor oxygenation. We thus overexpressed and purified a recombinant OprD homologue protein to further examine its functional properties. As a specific channel, this porin presented rather low single-channel conductance, i.e., 28 pS in 1 M KCl, and was partially closed by micro- and millimolar concentrations of Fe(3+) and Mg(2+), respectively, but not by imipenem and meropenem or basic amino acids. The A. baumannii OprD homologue is likely not involved in the carbapenem resistance mechanism, but as an OprQ-like protein, it could contribute to the adaptation of this bacterium to magnesium- and/or iron-depleted environments.

Inactivation of the gene encoding zinc-binding lipoprotein 103 impairs the infectivity of Streptococcus suis

The Streptococcus suis 103 gene product is an immunogenic and protective lipoprotein that is a component of an ATP-binding cassette transporter implicated in zinc uptake. Belonging to the same transcriptional unit and downstream of the 103 gene is a gene that encodes a homologue of the pneumococcal histidine triad (Pht) protein Pht309. In an intraperitoneal mouse model the virulence of a mutant lacking the 103 gene was more than 50 times lower than that of the wild-type (WT) parent strain, S. suis serotype 2 strain P1/7. In addition, the immunogenicity of this mutant was dramatically decreased. In striking contrast, the virulence and immunogenicity of a P1/7 mutant lacking the Pht309 gene were similar to those of the parent strain. These results demonstrate that the 103 lipoprotein is strongly involved in S. suis virulence and support the hypothesis that this lipoprotein might be an excellent candidate for vaccines aiming to achieve broad protection against streptococci.

A rapid and simple method for constructing stable mutants of Acinetobacter baumannii

Background

Acinetobacter baumannii is a multidrug-resistant bacterium responsible for nosocomial infections in hospitals worldwide. Study of mutant phenotypes is fundamental for understanding gene function. The methodologies developed to inactivate A. baumannii genes are complicated and time-consuming; sometimes result in unstable mutants, and do not enable construction of double (or more) gene knockout mutant strains of A. baumannii.

Results

We describe here a rapid and simple method of obtaining A. baumannii mutants by gene replacement via double crossover recombination, by use of a PCR product that carries an antibiotic resistance cassette flanked by regions homologous to the target locus. To demonstrate the reproducibility of the approach, we produced mutants of three different chromosomal genes (omp33, oxyR, and soxR) by this method. In addition, we disrupted one of these genes (omp33) by integration of a plasmid into the chromosome by single crossover recombination, the most widely used method of obtaining A. baumannii mutants. Comparison of the different techniques revealed absolute stability when the gene was replaced by a double recombination event, whereas up to 40% of the population reverted to wild-type when the plasmid was disrupting the target gene after 10 passages in broth without selective pressure. Moreover, we demonstrate that the combination of both gene disruption and gene replacement techniques is an easy and useful procedure for obtaining double gene knockout mutants in A. baumannii.

Conclusions

This study provides a rapid and simple method of obtaining stable mutants of A. baumannii free of foreign plasmidic DNA, which does not require cloning steps, and enables construction of multiple gene knockout mutants.

The cation-uptake regulators AdcR and Fur are necessary for full virulence of Streptococcus suis

In streptococci, the pleiotropic regulators AdcR and Fur control the transport of, zinc and iron, respectively, which are essential components of many proteins. In this work, DeltaadcR, Deltafur, and DeltaadcR Deltafur mutants of Streptococcus suis, a serious pathogen in pigs and humans, were assayed in a mouse model to determine their involvement in the virulence of this bacterium. The results showed, for the first time, that the virulence of S. suis mutants carrying an inactivation of adcR, fur, or both genes is significantly attenuated compared to the wild-type parent strain. Furthermore, all mutants were found to be more sensitive to oxidative stress. Our data provide evidence that the adcR and fur genes play important roles in the oxidative stress response of S. suis as well as in the full virulence of this bacterium.

Contribution of the FeoB transporter to Streptococcus suis virulence

The contribution of iron transporter systems encoded by feo genes to the pathogenic traits of streptococci is largely unknown, despite the fact that those systems are required for the full virulence of several gram-negative bacterial species. In this work, we show that the swine pathogen and zoonotic agent Streptococcus suis has a feoAB operon similar to that encoding an iron transporter system in Escherichia coli. Electrophoretic mobility assays and transcriptional analyses confirmed that the expression of S. suis feo genes is under the negative control of the ferric uptake regulator (Fur) protein. In vivo trials in mice using a feoB defective mutant strain were carried out to investigate the contribution of this gene to the virulence of S. suis. The results showed that the median lethal dose (LD50) of the mutant was approximately 10-fold higher than that of the wild-type parent strain. These data suggest that the Feo metal transporter plays a significant role in streptococcal infectious disease. This is in contrast to previous results reported for this same gene in other gram-positive bacterial species.

Psychological distress across the course of care: a case study from implantable cardioverter defibrillator to cardiac transplantation evaluation

The psychological distress of cardiac patients can complicate treatment or the recovery process. This case study presents a 47-year-old male recipient of an implantable cardioverter defibrillator who experienced multiple, consecutive shocks and subsequently developed anxiety and depressive difficulties. Psychological treatment to diminish these symptoms was employed. Despite declining cardiac function, the patient made significant progress in managing this negative affect. Subsequently, he was evaluated for cardiac transplant, and this treatment progress became critical evidence of his psychosocial suitability for transplant.

Isolation and sequencing of a temperate transducing phage for Pasteurella multocida

A temperate bacteriophage (F108) has been isolated through mitomycin C induction of a Pasteurella multocida serogroup A strain. F108 has a typical morphology of the family Myoviridae, presenting a hexagonal head and a long contractile tail. F108 is able to infect all P. multocida serogroup A strains tested but not those belonging to other serotypes. Bacteriophage F108, the first P. multocida phage sequenced so far, presents a 30,505-bp double-stranded DNA genome with cohesive ends (CTTCCTCCCC cos site). The F108 genome shows the highest homology with those of Haemophilus influenzae HP1 and HP2 phages. Furthermore, an F108 prophage attachment site in the P. multocida chromosome has been established to be inside a gene encoding tRNA(Leu). By using several chromosomal markers that are spread along the P. multocida chromosome, it has been demonstrated that F108 is able to perform generalized transduction. This fact, together with the absence of pathogenic genes in the F108 genome, makes this bacteriophage a valuable tool for P. multocida genetic manipulation.

Pancreas Islet Transplantation in Patients With Type 1 Diabetes Mellitus After Kidney Transplantation

Diabetic patients with end-stage renal disease have a high mortality rate. A combined kidney-pancreas transplant is associated with greater life expectancy. Pancreas islet transplantation is an alternative involving a lower degree of morbidity. We present two patients, of 41 and 37 years of age, with a long history of diabetes mellitus (C-peptide negative), both with a previous kidney transplant, who had been treated with 22 and 28 U of insulin/d, respectively. Both patients had frequent episodes of unawareness hypoglycemia. Pancreatic islets were infused to a total of 7809 and 19,180 IE/kg, respectively. Basal posttransplant C peptide levels were 2.9 and 1.3 ng/mL. After the implant, one patient required occasional doses of insulin, and the other patient more than 50% reduced dose. After the first implant neither patient had any episodes of unawareness hypoglycemia. HbA1c at 4 months were 6.2% and 6.9%. There were no transplant-related complications.

Doxorubicin in combination with fluorouracil and cyclophosphamide (i.v. FAC regimen, day 1, 21) versus methotrexate in combination with fluorouracil and cyclophosphamide (i.v. CMF regimen, day 1, 21) as adjuvant chemotherapy for operable breast cancer: a study by the GEICAM group

BACKGROUND

The purpose of this study was to determine the relative efficacy of doxorubicin versus methotrexate in combination with intravenous cyclophosphamide and 5-fluorouracil (FAC versus CMF) as adjuvant chemotherapy for operable breast cancer.

PATIENTS AND METHODS

Over a 4-year period, 985 women undergoing curative surgery for breast cancer (T1-3 N0-2 M0, stage I-IIIA, UICC) from nine hospitals were stratified with respect to axillary node involvement (node positive versus node negative) and randomized to receive either FAC (500/50/500/m(2)) every 3 weeks for six cycles or CMF (600/60/600/m(2)) every 3 weeks for six cycles.

RESULTS

The relative dose intensities of FAC and CMF were 87% and 85% of planned doses, respectively. Unadjusted data indicated a non-significant trend towards better results with FAC. In the prospectively formed subset of node-negative patients, disease-free survival and overall survival were statistically superior in the FAC treatment arm (P = 0.041 and 0.034, respectively), but this advantage was not seen in the subset of node-positive patients, probably because of a difference in the percentage of patients with four or more positive nodes. Adjusting data for size of treatment effect and potential interactions (number of positive nodes, tumor size, treatment center), the overall relative risk (RR) of disease recurrence and death were significantly lower with FAC treatment (RR 1.2, P = 0.03, and RR 1.3, P = 0.05, respectively). This result was mainly due to the difference observed in the node-negative patient population. Toxicity was mild: FAC induced more alopecia, emesis, mucositis and cardiotoxicity; this last was of clinical concern, but was infrequent and manageable. CMF induced more conjunctivitis and weight gain. There were no toxic deaths.

CONCLUSIONS

Doxorubicin in combination with day 1 i.v. cyclophosphamide and 5-fluorouracil is superior to methotrexate in combination with day 1 i.v. cyclophosphamide and 5-fluorouracil as adjuvant chemotherapy for operable breast cancer. A treatment effect is particularly evident in the node-negative patients. Although the clinical toxicity of FAC is greater than that of CMF, the levels were manageable and clinically acceptable.

The neurosensory tachykinins substance P and neurokinin A directly induce keratinocyte nerve growth factor

Nerve growth factor is an essential neurotrophic factor required for the growth and maintenance of cutaneous sensory nerves. In the skin, keratinocytes are a significant source of nerve growth factor; however, the regulation of cutaneous nerve growth factor production still remains to be fully understood. In this study we tested the hypothesis that neuropeptides released by cutaneous sensory nerves have the capacity to modulate directly the expression of keratinocyte nerve growth factor, which would have important implications for the maintenance and repair of nerves in the skin. In order to address this question experimentally we examined the effect of the neuropeptides, substance P and neurokinin A, on nerve growth factor expression in human keratinocytes and the murine keratinocyte PAM 212 cell line by quantitative reverse transcriptase-polymerase chain reaction, enzyme-linked immunosorbent assay, and the PC-12 nerve growth factor bioassay. The results of these studies indicated that substance P and neurokinin A can directly induce nerve growth factor mRNA expression and the secretion of bioactive nerve growth factor protein in both human and murine keratinocytes. The specificity of these responses was demonstrated using neuropeptide receptor antagonists and nerve growth factor blocking antibodies. Additional studies also demonstrated a significant in vivo upregulation of keratinocyte nerve growth factor expression in murine epidermis after the topical application of the neuropeptide releasing agent capsaicin. This is the first report demonstrating the induction of cutaneous nerve growth factor by sensory nerve-derived neuropeptides such as substance P and neurokinin A. This direct effect of the neurosensory system on keratinocyte nerve growth factor production may have important consequences for the maintenance and regeneration of cutaneous nerves in normal skin and during inflammation and wound healing.

Effect of increased brain GABA concentrations on breathing in unanesthetized newborn rabbits

Evidence suggests that gamma-aminobutyric acid (GABA) is involved in control of breathing and in the hypoxia-related ventilatory depression in newborns. However, this evidence is obtained mainly from studies on anesthetized animals. Because anesthesia may interfere with the GABA system, the objectives of our study were to examine effects of GABA on ventilation (V(E)) and ventilatory response to hypoxia and to reveal effects of repeated hypoxia on GABA concentrations in unanesthetized newborns. The study was performed in rabbits in two age groups: 1-3 days old (group I) and 10-14 days old (group II). To increase brain endogenous GABA concentrations, rabbits were injected with an inhibitor of GABA transaminase, aminooxyacetic acid (AOAA; 20 mg/kg i.p.). To prevent postmortem formation of GABA, at the end of experiments the rabbits received an inhibitor of glutamic acid decarboxylase, IP-3-mercaptopropionic acid (100 mg/kg i.p.). Animals were studied in normoxia alone, or they were exposed for 15 min to 8% O(2) before and 10 and 35 min after saline or AOAA. GABA concentrations were measured in brainstem, cerebrum, and cerebellum by means of a capillary electrophoresis. In group I, AOAA had no respiratory effects. In group II, AOAA decreased V(E), tidal volume, and mean inspiratory flow in normoxia and reversed V(E) decline during hypoxia 10 min after the injection, GABA concentrations were not age dependent and the highest in the brainstem. Repeated hypoxia increased the cerebellar GABA concentrations and had no effect in group I. These results imply that in unanesthetized rabbits, GABAergic neurotransmission in the respiratory control network becomes functional by the 2nd week of life, but it does not contribute to the biphasic ventilatory response to moderate hypoxia. In contrast, GABA-evoked block of the cerebellar inhibitory input during hypoxia may be responsible for the reversal of the V(E) decline in unanesthetized newborns.

Management of pain from heel lance with lidocaine-prilocaine (EMLA) cream: is it safe and efficacious in preterm infants?

Hospitalized preterm infants undergo multiple painful heel lances. A two-phase, randomized, controlled trial was undertaken to determine the safety and efficacy of lidocaine-prilocaine 5% cream (EMLA, Astra Pharmaceuticals, L.P, Westborough, MA) for relieving pain from heel lance. One hundred twenty infants were randomly assigned to receive 0.5 g of EMLA or placebo cream for 30 minutes (Phase 1) or 60 minutes (Phase 2) before a routine heel lance. Efficacy was assessed using the Premature Infant Pain Profile (PIPP). Safety was determined by methemoglobin concentration 8 hours after EMLA application and by clinical signs of methemoglobinemia. No significant differences existed on PIPP scores between EMLA and placebo groups in Phase 1 (p < .480) or Phase 2 (p < .831). No infant had any clinical signs of methemoglobinemia. The mean methemoglobin concentration was 1.19% (.47). Approximately 10% of infants had minor skin reactions, and approximately 20% of EMLA-treated infants had blanching at the application site. The authors conclude that EMLA is safe but not efficacious for relieving pain from heel lance in preterm infants.

Endovascular stenting of an unprotected left main coronary artery stenosis in a heart transplant patient

Endoluminal revascularizaion of left main coronary artery vessels is considered to be relatively contraindicated because of a high procedural mortality and restenosis rate. This report describes the first successful case of endovascular stenting in an unprotected left main coronary artery stenosis in a heart transplant patient.

Pseudoaneurysm of the thoracic aorta presenting as purulent pericarditis and pericardial effusion

Report of a case of a mycotic pseudoaneurysm of the ascending thoracic aorta occurring in the absence of surgical or blunt trauma in a patient who presented with purulent pericarditis. Surgical pericardial drainage was required, which revealed Staphlococcal aureus. Subsequent transesophageal echocardiogram demonstrated a 4 cm x 4 cm pseudoaneurysm of the posterior wall of the aorta above the sinotubular junction. The patient refused surgical correction of the aortic pseudoaneurysm and was successfully managed with antibiotic therapy.