[Dumbbell-shaped spinal epidural cavernous angioma. Case report and review of the literature]

Spinal epidural cavernous angiomas are rare vascular malformations that exceptionally present with dumbbell-shape morphology. When it happens, preoperative misdiagnosis is the rule, because the clinicoradiological picture is quite similar to the nerve sheath tumours one. Spinal epidural cavernomas complete resection can be achieved with surgical treatment and scarcely morbi-mortality, and excellent outcome can be expected. We report a case of a 57 year-old woman carrying a dumbbell-shaped epidural cavernoma located at C7 and D1 levels that was surgically removed. Special diagnostic features of this kind of lesions are discussed and treatment options currently available are reviewed.

Strategies for the development of a side stream process for polyhydroxyalkanoate (PHA) production from sugar cane molasses

A three-stage process was developed to produce polyhydroxyalkanoates (PHAs) from sugar cane molasses. The process includes (1) molasses acidogenic fermentation, (2) selection of PHA-accumulating cultures, (3) PHA batch accumulation using the enriched sludge and fermented molasses. In the fermentation step, the effect of pH (5-7) on the organic acids profile and productivity was evaluated. At higher pH, acetic and propionic acids were the main products, while lower pH favoured the production of butyric and valeric acids. PHA accumulation using fermented molasses was evaluated with two cultures selected either with acetate or fermented molasses. The effect of organic acids distribution on polymer composition and yield was evaluated with the acetate selected culture. Storage yields varied from 0.37 to 0.50Cmmol HA/Cmmol VFA. A direct relationship between the type of organic acids used and the polymers composition was observed. Low ammonia concentration (0.1Nmmol/l) in the fermented molasses stimulated PHA storage (0.62Cmmol HA/Cmmol VFA). In addition, strategies of reactor operation to select a PHA-accumulating culture on fermented molasses were developed. The combination of low organic loading with high ammonia concentration selected a culture with a stable storage capacity and with a storage yield (0.59Cmmol HA/Cmmol VFA) similar to that of the acetate-selected culture.

Successive positive contrast in one-way avoidance behavior with Roman low-avoidance rats

The inbred Roman High- (RHA-I) and Roman Low-Avoidance (RLA-I) rats, psychogenetically selected for rapid (RHA-I) vs. extremely poor (RLA-I) acquisition of two-way active avoidance, exhibit a lower or a higher level of fearfulness, respectively, that can be observed in many laboratory anxiety models. The present study analyzed the performance of female RLA-I and RHA-I rats in a successive positive contrast situation induced during one-way avoidance learning. Three groups of RLA-I and three of RHA-I rats (1-30, 30-30 and 1-1 groups, the numbers stand for the time spent in the safe compartment during the first and second phase of training) were trained to avoid an electric foot-shock administered in a "danger" compartment, by running from this compartment to a "safe" one. Only RLA-I rats showed a significant positive contrast effect, in such a way that the reinforcement increase from the lower (1 s spent in safety) to the higher reward (30 s) led to a response enhancement, surpassing the performance of rats trained with the low (1-1 s) or the high (30-30 s) reward from the beginning of training. The results are discussed in the context of an opponent process theory based upon the interaction between the motivational strength of fear and the incentive value of relief taking place during one-way avoidance learning.

Detection of virulence factors in high-level gentamicin-resistant Enterococcus faecalis and Enterococcus faecium isolates from a Tunisian hospital

Phenotypic and genotypic determination of virulence factors were carried out in 46 high-level gentamicin-resistant (HLGR) clinical Enterococcus faecalis (n = 34) and Enterococcus faecium (n = 12) isolates recovered from different patients in La Rabta Hospital in Tunis, Tunisia, between 2000 and 2003 (all these isolates harboured the aac(6′)–aph(2″) gene). The genes encoding virulence factors (agg, gelE, ace, cylLLS, esp, cpd, and fsrB) were analysed by PCR and sequencing. The production of gelatinase and hemolysin, the adherence to caco-2 and hep-2 cells, and the capacity for biofilm formation were investigated in all 46 HLGR enterococci. The percentages of E. faecalis isolates harbouring virulence genes were as follows: gelE, cpd, and ace (100%); fsrB (62%); agg (56%); cylLLS (41.2%); and esp (26.5%). The only virulence gene detected among the 12 HLGR E. faecium isolates was esp (58%). Gelatinase activity was detected in 22 of the 34 E. faecalis isolates (65%, most of them with the gelE+–fsrB+ genotype); the remaining 12 isolates were gelatinase-negative (with the gelE+–fsrB– genotype and the deletion of a 23.9 kb fragment of the fsr locus). Overall, 64% of the cylLLS-containing E. faecalis isolates showed β-hemolysis. A high proportion of our HLGR E. faecalis isolates, in contrast to E. faecium, showed moderate or strong biofilm formation or adherence to caco-2 and hep-2 cells.

Diversity of structures carrying the aac(6')-aph(2") gene in clinical Enterococcus faecalis and Enterococcus faecium strains isolated in Tunisia

The diversity of structures carrying the aac(6')-aph(2") gene was studied in 46 high-level gentamicin-resistant Enterococcus faecalis and Enterococcus faecium clinical strains recovered in a Tunisian hospital during the period 2000-2003. The inclusion of the aac(6')-aph(2") gene within the Tn4001 composite element or in its truncated forms (lacking the IS256 at the right, the left or at both sides of the aac(6')-aph(2") gene) was investigated by PCR and sequencing. The aac(6')-aph(2") gene was included in the composite Tn4001 element in 19 of 34 high-level gentamicin-resistant E. faecalis strains (56%) and in 1 of 12 E. faecium strains (12%). A truncated form of Tn4001 lacking IS256 at the left-hand (in 10 E. faecalis and 8 E. faecium), at the right-hand (3 E. faecalis and 2 E. faecium) or at both sides of the aac(6')-aph(2") gene (in 2 E. faecalis and 1 E. faecium) was also detected in 26 of our enterococci. The transference by conjugation of the aac(6')-aph(2") gene, associated with other resistance genes, was demonstrated in seven of the high-level gentamicin-resistant E. faecalis strains.

Phenotypic and genotypic study of gelatinase and beta-haemolysis activities in faecal enterococci of poultry in Portugal

The detection of gelatinase and beta-haemolysis activities was carried out in 83 faecal enterococci (43 Enterococcus faecalis, 33 E. faecium, five E. durans and two E. hirae) of poultry origin. In addition, the presence of genes of the gelE-fsrABC locus and of the cyl operon (cylL(L), cylL(S), cylA, cylB and cylM) were studied by polymerase chain reaction and correlated with gelatinase and beta-haemolysis production, respectively. Most of our E. faecalis isolates were gelatinase-positive (88%), being this activity not frequent in the other enterococcal species (2.5%). Only one of the 33 E. faecium isolates showed a positive gelatinase reaction. All enterococci that showed gelatinase activity harboured the gelE and fsrABC genes, although these genes were also detected in four E. faecalis and one E. durans gelatinase-negative isolates. Most of our non-E. faecalis gelatinase-negative isolates did not harbour gelE-fsrABC genes. A high proportion of faecal enterococci of poultry origin harboured genes of the cyl operon (71%), although only 7% contained the five cyl tested genes (all of them E. faecalis). Only one isolate of our series could express beta-haemolysis, harbouring the whole cyl operon. The cylL(S) genotype was the most prevalent in our enterococci (39%) and also the most prevalent among our E. faecalis isolates (60%). Other genotypes detected were the following ones (% of enterococci): cylA + cylB + cylM (13%), cylL(L) + cylA (4%), cylL(L) (4%), cylL(L) + cylA + cylB + cylM (2%), cylL(L) + cylA + cylM (1%) and cylA + cylM (1%). Both phenotypic and genotypic assays are important to evaluate the virulence potential of enterococci.

Antibiotic resistance and mechanisms implicated in clinical enterococci in a Tunisian hospital

Susceptibility testing for 15 antibiotics was performed in a series of 191 clinical enterococci recovered in a Tunisian Hospital during 2000-2003. Species detected were the following ones (number of isolates): E. faecalis (139), E. faecium (41), E. casseliflavus (5), E. gallinarum (3), E. avium (2) and E. hirae (1). The percentages of antibiotic resistance detected were as follows (E. faecalis/ E. faecium/ other species) : penicillin (0/ 73/ 9%), tetracycline (78/ 44/ 54%), chloramphenicol (52/ 29/ 27%), erythromycin (66/ 100/ 82%), spiramycin (84/ 83/ 64%), pristinamycin (100/ 0/ 73%), trimethoprim-sulfamethoxazole (88/ 78/ 91%), rifampicin (72/ 41/ 0%), vancomycin (0/ 0/ 36%), teicoplanin (0/ 0/ 0%), high-level-resistance for gentamicin (24/ 29/ 45%), streptomycin (34/ 56/ 55%) and kanamycin (41/ 68/ 55%). Increased vancomycin minimum inhibitory concentrations (MICs) were only detected in E. casseliflavus and E. gallinarum isolates (MIC range 8-24 microg/ml). The erm(B), catA, tet(M), aac(6')-aph(2''), aph(3')-IIIa, and ant(6)-Ia genes were detected in 91%, 32%, 86%, 98%, 100%, and 72% of the E. faecium and E. faecalis isolates resistant to erythromycin, chloramphenicol, tetracycline and high-level-resistant to gentamicin, kanamycin and streptomycin, respectively. A total of 20 unrelated pulsed-field-gel-electrophoresis patterns were found in the series of 46 high-level gentamicin-resistant E. faecalis and E. faecium isolates of this study.

Upper limits on a stochastic background of gravitational waves

The Laser Interferometer Gravitational-Wave Observatory has performed a third science run with much improved sensitivities of all three interferometers. We present an analysis of approximately 200 hours of data acquired during this run, used to search for a stochastic background of gravitational radiation. We place upper bounds on the energy density stored as gravitational radiation for three different spectral power laws. For the flat spectrum, our limit of omega0 < 8.4 x 10(-4) in the 69-156 Hz band is approximately 10(5) times lower than the previous result in this frequency range.

Characterization of Antibiotic Resistance Genes and Virulence Factors in Faecal Enterococci of Wild Animals in Portugal

Antibiotic susceptibility was tested in 140 non-selected enterococci (73 Enterococcus faecalis, 45 E. faecium and 22 of other species) recovered from faecal samples of 77 wild animals in Portugal. Susceptibility testing for 11 antibiotics (vancomycin, teicoplanin, ampicillin, streptomycin, gentamicin, kanamycin, chloramphenicol, tetracycline, erythromycin, quinupristin-dalfopristin and ciprofloxacin) was determined by disk diffusion and agar dilution methods. Forty-four isolates (31.4%) showed susceptibility to all the antibiotics tested (5.5% of E. faecalis; 62.2% of E. faecium; and 78.6% of E. hirae). Neither ampicillin-resistance nor acquired-vancomycin-resistance was detected and 1.4% of the isolates showed high-level-resistance for gentamicin or streptomycin. Tetracycline and erythromycin resistances were shown in 28.6% and 20.1% of the isolates, respectively. Antibiotic resistance genes were studied by polymerase chain reaction (PCR) and sequencing and tet(M) + tet(L), erm(B) or aac(6')-aph(2'') genes were detected in most of tetracycline-, erythromycin- or gentamicin-resistant enterococci respectively. Genes encoding virulence factors were studied by PCR and a wide variety of virulence genes were detected in most of E. faecalis isolates but were rarely found in E. faecium and not detected in the other species. The prevalence of genes encoding virulence factors in E. faecalis was as follows: cpd (98.6%), gelE (75.3%), agg (30.1%), fsr (17.8%), ace (9.6%) and esp (4.1%). Low percentages of antibiotic resistance was found in the faecal enterococci of wild animals but a wide variety of virulence genes were detected among E. faecalis isolates although were rare in the other species.

AS2TS system for protein structure modeling and analysis

We present a set of programs and a website designed to facilitate protein structure comparison and protein structure modeling efforts. Our protein structure analysis and comparison services use the LGA (local-global alignment) program to search for regions of local similarity and to evaluate the level of structural similarity between compared protein structures. To facilitate the homology-based protein structure modeling process, our AL2TS service translates given sequence–structure alignment data into the standard Protein Data Bank (PDB) atom records (coordinates). For a given sequence of amino acids, the AS2TS (amino acid sequence to tertiary structure) system calculates (e.g. using PSI-BLAST PDB analysis) a list of the closest proteins from the PDB, and then a set of draft 3D models is automatically created. Web services are available at .

Successive negative contrast in one-way avoidance learning in female roman rats

The inbred RLA (Roman Low-Avoidance) and RHA (Roman High-avoidance) rat strains have been psychogenetically selected for rapid (RHA) vs. extremely poor acquisition (RLA) of two-way active avoidance. As a consequence of this selective breeding, RLA animals exhibit a higher level of emotionality that can be observed in many anxiety models. The present study was conducted in order to analyze the performance of female RLA, RHA and Wistar rats in a behavioral test of anxiety that involves the reduction of the magnitude of an expected reward: the negative contrast effect that is obtained in one-way avoidance learning by reducing the time spent in the safe compartment. To this aim, three groups of animals (30-1/RLA, 30-1/RHA and 30-1/W) were trained to avoid an electric foot-shock administered in a "danger" compartment, by running from this compartment to a "safe" compartment. We observed an impairment of the avoidance response when time spent in the safe compartment was reduced from 30 to 1 s, when 30-1/RLA and 30-1/W groups were compared with control groups that were trained with a constant safe time (1-1/RLA and 1-1/W, respectively). We also obtained significant differences between 30-1/RLA and 30-1/RHA groups in the postshift phase. These results indicate that RLA rats respond more negatively to the frustration triggered by the reduction in time spent in the safe compartment, suggesting that animal models based on negative contrast effects can be useful tools for studying the genetic basis of anxiety.

Limits on gravitational-wave emission from selected pulsars using LIGO data

We place direct upper limits on the amplitude of gravitational waves from 28 isolated radio pulsars by a coherent multidetector analysis of the data collected during the second science run of the LIGO interferometric detectors. These are the first direct upper limits for 26 of the 28 pulsars. We use coordinated radio observations for the first time to build radio-guided phase templates for the expected gravitational-wave signals. The unprecedented sensitivity of the detectors allows us to set strain upper limits as low as a few times 10(-24). These strain limits translate into limits on the equatorial ellipticities of the pulsars, which are smaller than 10(-5) for the four closest pulsars.

[Susceptibility of Enterococcus genus to new antimicrobial agents]

The aim of this study was to determine the prevalence of resistance to different antibiotics in 109 clinical strains of Enterococcus isolated consecutively in hospital over a four-month period in 2002. The strains were identified by species using the semiautomatic system Microscan walk away 40 (Dade Behring) and the API20 STREP system (Biomerieux). Three different methods for the susceptibility study were used: Sensititre, E-test and disc diffusion. The percentage of Enterococcus faecalis and Enterococcus faecium isolated was 92% and 8%, respectively. The following resistance to Enterococcus faecalis was detected: erythromycin (53%), telithromycin (36%), penicillin (2%), ampicillin (1%), vancomycin, teicoplanin and linezolid (0%), high level resistance to streptomycin (51%) and gentamicin (32%). A high percentage of strains resistant to penicillin and ampicillin was detected in E. faecium (six of nine strains). For two species, high susceptibility to linezolid and glycopeptides was found.

Functional liver recovery parallels autologous gut salvage in short bowel syndrome

BACKGROUND/PURPOSE

Parenteral nutrition (PN) is life saving in short bowel syndrome. However, long-term parenteral nutrition is frequently complicated by a syndrome of progressive cholestatic liver disease that is considered to be irreversible beyond the early stages of cholestasis, particularly in the presence of any degree of fibrosis in the liver. The purpose of this study was to examine apparent improvement in PN-associated liver dysfunction in a cohort of children with short bowel syndrome.

METHODS

A retrospective case-record review of all patients managed within a dedicated Intestinal Rehabilitation Program (IRP) identified 13 patients with short bowel who had PN-associated liver dysfunction, defined for this purpose as hyperbilirubinemia or an abnormal liver biopsy.

RESULTS

At referral, 12 of the 13 patients were exclusively on PN, and one was on 50% PN. At current follow-up, 3 patients have achieved complete enteral autonomy from PN, and 7 patients have had smaller decrements in PN requirements. Specific operative procedures to improve intestinal function were undertaken in 11 patients; 4 patients also underwent cholecystectomies with biliary irrigation at the time of intestinal reconstruction. The median highest bilirubin level in these 13 patients was 10.7 mg% (range, 3.2 to 24.5 mg%). Liver biopsy results indicated that 5 patients were cirrhotic, 3 had bridging fibrosis, and 4 had severe cholestasis or lesser degrees of fibrosis. Of 10 survivors in this series, 9 patients currently have a serum bilirubin less than 1 mg% with a median bilirubin in the group of 0.6 mg% (range, 0.3 to 6.4 mg%). Twelve of the 13 patients in this series were initially referred for liver-small bowel transplantation.

CONCLUSIONS

This preliminary experience suggests that PN-dependent patients with advanced liver dysfunction in the setting of the short bowel syndrome may, in some instances, experience functional and biochemical liver recovery. The latter appears to parallel autologous gut salvage in most cases. As a corollary, the authors believe that even advanced degrees of liver dysfunction should not preclude attempts at autologous gut salvage in very carefully selected patients. Such a policy of "aggressive conservatism" may help avoid the need for liver/intestinal transplantation in some patients who appear to be not responding to PN.

Antimicrobial resistance in recent fecal enterococci from healthy volunteers and food handlers in Spain: genes and phenotypes

Susceptibility patterns to 15 different antibiotics and the presence of resistance genes were evaluated in recent fecal Enterococcus isolates recovered from 42 healthy volunteers (HV) and 43 food-handlers (FH). A total of 142 Enterococcus faecalis, 74 Enterococcus faecium, and 23 Enterococcus spp. with different antibiotic susceptibility patterns were studied. A higher percentage of resistance for moxifloxacin, erythromycin, glycopeptides and high-level resistance (HLR) to gentamicin were observed in the FH group. Ampicillin- or linezolid-resistant isolates were not recovered in any of the groups. The tet(M) gene was found in 96% and in 85% of tetracycline-resistant isolates from HV and FH, respectively. HLR-kanamycin was mediated by aph(3')-IIIa, or aac(6')-aph(2"), or both genes in all isolates from HV group and in 86% from FH group. The aac(6')-aph(2") gene was found in all HLR-gentamicin isolates. Ninety-one percent of HV and 71% of FH erythromycin-resistant isolates harbored the erm(B) gene (erythromycin MIC range of 8-128 microg/ml), whereas erm(A), erm(C), or mef(A) genes were not detected. Coexistence of erm(B), aph(3')-IIIa, and tet(M) genes was observed in 17% of the isolates of both groups. The HLR-gentamicin isolates presented unrelated PFGE patterns while 2 out of 3 vanA E. faecium isolates showed an indistinguishable SmaI-pulsed-field gel electrophoresis (PFGE) pattern. This study shows that despite 4 years of official banning of antibiotic growth promoters in animals, enterococci isolated from FH are more resistant than those from HV. This suggests the permanence of resistant clones or transferable resistance elements in farms and a possible exchange between food products and humans, or eventually the long-term permanence of certain clones in the FH intestinal tract.

Clonal diversity among erythromycin-resistant beta-haemolytic Streptococcus isolates in La Rioja, Spain

OBJECTIVE

To analyse clonal diversity in 72 erythromycin-resistant beta-haemolytic streptococci.

METHODS

Clonal relationships were studied for streptococci of groups A (GAS, n = 30), B (GBS, n = 34), C (GCS, n = 4) and G (GGS, n = 4) by means of PFGE. Streptococcal isolates were obtained from a 450-bed hospital in Spain during the following periods: GAS (1996-2001), GBS (1999-2001), GCS and GGS (1997-2000).

RESULTS

Twenty-two of the 30 GAS isolates showed the M resistance phenotype and harboured the mef(A) gene. Five unrelated PFGE patterns were identified among these 22 GAS isolates. Sixteen of them, obtained during four different years of the study, showed one of the two predominant PFGE patterns. The remaining eight GAS isolates showed the MLSB resistance phenotype, and four unrelated PFGE patterns were detected. All but one erythromycin-resistant GBS showed the MLSB resistance phenotype, and an erm gene was identified in all cases [erm(B) or erm(A)]. Twenty-two unrelated PFGE patterns were demonstrated among 25 GBS with the MLSB resistance phenotype; the remaining eight MLSB GBS isolates could not be typed by PFGE. The eight erythromycin-resistant GGS and GCS isolates of this study presented seven unrelated PFGE patterns. GGS and GCS strains showed an MLSB resistance phenotype and had the erm(A) gene.

CONCLUSIONS

High clonal diversity was detected in this series of erythromycin-resistant GBS, whereas lower diversity was seen in the GAS isolates.