Neck-bridge device for endovascular treatment of wide-neck bifurcation aneurysms: initial experience

PURPOSE

To report the authors' initial experience in treating patients with wide-neck aneurysms with assistance from a recently developed neck-bridge device (TriSpan; Target Therapeutics/Boston Scientific, Fremont, Calif).

MATERIALS AND METHODS

Twenty-five patients were examined. Aneurysms were most frequently at the basilar bifurcation (n = 19). Sixteen aneurysms were treated electively: six aneurysms that recurred after coil-only embolization and 10 nontreated aneurysms (including four that had failed coil-only embolization). Nine aneurysms were treated acutely following subarachnoid hemorrhage. All lesions except one had a wide neck. A dual-catheter technique was used in 23 patients. Immediate angiographic results, technical incidents, and complications were recorded. Follow-up angiography was performed in 16 patients. Clinical follow-up ranged from 1 to 12 months.

RESULTS

Neck-bridge device-assisted coil packing was successfully performed in 23 lesions, with complete obliteration in three, residual necks in 13, and a minimal residual sac in seven patients. Parent vessel protection failed, with coil protrusion and arterial occlusion, in one of these patients. Other complications that were not directly related to use of the neck-bridge device included retroperitoneal hematoma, rebleeding, coil perforation, and transient embolic arterial occlusion. One patient died of vasospasm and heart failure. Follow-up angiography revealed complete obliteration in four, a residual neck in one, a persistent residual sac in four, and recurrent aneurysm in seven patients. One patient had a small occipital infarction 5 weeks after treatment.

CONCLUSION

The described neck-bridge device is useful for assisting coil embolization of wide-neck bifurcation aneurysms.

Meningoencephalitis in a Boelen's python (Morelia boeleni) associated with paramyxovirus infection

An adult male Boelen's python, Morelia boeleni, presented with acute neurologic disease and was euthanatized. Histologic examination revealed nonsuppurative meningoencephalitis. Occasional eosinophilic intracytoplasmic inclusions were noted in glial cells. On the basis of clinical signs and histopathology, inclusion body disease of boid snakes was suspected, but inclusions were not seen in other organs commonly affected with the disease. Moreover, electron microscopy revealed that the inclusions contained stacks of filaments 13-14 nm wide. With the use of a generic paramyxovirus cDNA probe, sections of brain and esophageal ganglion demonstrated hybridization. The findings indicate that paramyxovirus was the likely cause of the encephalomyelitis in this python, and this virus should be included in the differential diagnosis of pythons exhibiting central nervous system disease.

[Impact of bacterial resistance on severe infections]

Since many years, the antimicrobial resistance increases as well as for community-acquired as for nosocomial infections. Antibiotic-resistant pneumococci are neither more nor less virulent susceptible strains. Except for immunocompromised patients, the outcome of penicillin-resistant pneumococcal infections have been similar to those in patients who are infected by susceptible ones. Current levels of S. pneumoniae resistance to penicillin and cephalosporin are not associated to an increase in mortality in children with meningitis if adequate doses of antibiotics are given. Because empiric therapy has changed, antibiotic resistance has not been associated with increased mortality. This statement can be extended to Meningococcus, for which 32 to 50% of the strains have a decreased susceptibility to penicillin. For nosocomial infections, S. aureus is the main studied pathogen. Several studies report that in patients with severe diseases (bacteremia or pneumonia) methicillin resistance of S. aureus had no significant impact on patient outcome after adjustment for different confounders. The main risk factor for mortality is the severe underlying diseases rather than the resistance as well for methicillin--resistant S. aureus, as for vancomycin resistant enterococci, Klebsiella with extended spectrum beta lactamase and Enterobacters. Recommendations for controlling epidemiologic surveillance, using barrier precautions and limiting the use of antibiotics as well in the hospital as in the community must be undertaken.

Endovascular treatment of unruptured aneurysms

BACKGROUND AND PURPOSE

We sought to better define the morbidity of endovascular Guglielmi detachable coil (GDC) treatment of unruptured cerebral aneurysms and to discuss its role in the prevention of subarachnoid hemorrhage.

METHODS

We conducted an observational study from August 1992 to June 1999 of 125 unruptured aneurysms treated with GDC in 116 patients: 91 women (78.4%) and 25 men (21.6%), aged 30 to 78 years (mean age, 50.6 years). Immediate and late clinical results were recorded for any neurological event or hemorrhage related to the treated unruptured aneurysm. Angiographic results are reported as immediate, early (2 to 12 months), intermediate (12 to 30 months), and late follow-up (>30 months).

RESULTS

Immediate angiographic results showed complete obliteration (class 1) in 59 (47.2%) or residual neck (class 2) in 53 aneurysms (42.4%), leaving 6 residual aneurysms (4.8%) and 7 failures (5.6%). Early follow-up angiograms, available in 100 treated aneurysms (84%), revealed class 1 in 52% and class 2 in 41%. Intermediate angiograms, available in 53 aneurysms (44.5%), showed class 1 in 47.2% and class 2 in 43.4%, while late results, available in 37 lesions (31.1%), had class 1 and 2 in 48.6% and 37.8%, respectively. Six patients suffered a permanent neurological deficit at last follow-up (5.2%), with a good outcome in 5 patients and fair outcome in 1 patient. There was no mortality. There was no aneurysmal rupture during a mean clinical follow-up of 32.1 months.

CONCLUSIONS

Endovascular treatment with GDC for unruptured aneurysms is relatively safe. Its role in the prevention of aneurysmal rupture remains to be determined, preferably by a randomized study.

Nasopharyngeal colonization by Haemophilus influenzae in children living in an orphanage

AIM

To study colonization and transmission of Haemophilus influenzae in a cohort of children <2 years old living in the unique epidemiologic conditions of a closed community of an orphanage.

METHODS

Fifty-three children, ages 0 to 24 months, were followed for 1 year. All children >2 months were vaccinated against H. influenzae serotype b. Nasopharyngeal cultures were collected monthly or, in children <6 months of age, every 2 weeks. Antibiotic susceptibility, serotype, biotype and genotype (pulsed field gel electrophoresis) of each isolate were determined. As control, 39 H. influenzae isolates were recovered from various regions in France.

RESULTS

The mean monthly rate of carriage was 45% ranging from 17 to 70%. Most isolates belonged to biotype II (62%), 4 isolates to serotype f (3.6%) and none to serotype b, and 60% of the 111 isolates produced beta-lactamase. A complete concordance was found among biotype, serotype, pulsotype and antimicrobial susceptibility. On average children were sequentially colonized by 3 different isolates. The mean duration of carriage for a given isolate was approximately 1.4 months. In younger children the mean age of primary colonization was 2 months. Contrasting with the high genetic heterogeneity of 39 control isolates, most isolates (82%) belonged to only 5 pulsotypes. Three main H. influenzae clones rapidly spread in the community and colonized children in waves.

CONCLUSION

During early life nasopharyngeal colonization by H. influenzae is a dynamic phenomenon with sequential carriage of various clones spreading in the community.

Cardiovascular responses during arm exercise and orthostatic challenge in individuals with paraplegia

In this study the cardiorespiratory responses during arm crank ergometry (ACE) performed at two submaximal intensities (30% and 50% of heart rate reserve) and moderate orthostatic challenge were investigated in individuals with paraplegia (PARA). The effect of concurrent electrical stimulation (ES)-induced leg muscle contractions on the responses to ACE during orthostatic challenge was also investigated. Eight PARA (T5-T12) and eight able-bodied (AB) individuals participated in this study, however only seven subjects from each group completed all tests and were used in subsequent data analyses. Oxygen uptake (VO2), heart rate (fc), stroke volume (SV) and cardiac output (Qc) were assessed during (1) ACE alone, (2) ACE and lower body negative pressure (ACE + LBNP), and, in PARA only, (3) ACE + LBNP with ES (ACE + LBNP+ ES). In both PARA and AB, ACE + LBNP decreased SV (by 13-18% and 20-23%, respectively) and increased fc (by 13-15% and 16%, respectively) compared to ACE alone. The decrease in SV was greater in AB than in PARA (significant group x trial interaction; both ACE intensities pooled), but there was no difference in the magnitude of increase in fc between groups. ES-induced leg muscle contractions increased SV (up to 16%) but did not change VO2 or Qc. The smaller reduction in SV from ACE to ACE + LBNP in PARA may indicate a mechanism by which adequate central blood volume can be maintained in the face of orthostatic challenge, despite the absence of supraspinal control below the spinal cord lesion. With ES-induced leg muscle contractions, the decrease in SV, which occurred during ACE + LBNP, was reversed via reactivation of the lower limb muscle pump and augmented venous return.

Clarithromycin resistance and eradication of Helicobacter pylori in children

Outcome of Helicobacter pylori infection was analyzed in 61 children treated with a triple therapy including clarithromycin. Bacterial eradication was obtained in all children with clarithromycin-susceptible strains but not in children with clarithromycin-resistant ones (P = 0.0001). H. pylori antimicrobial susceptibility is mandatory before choosing a treatment, and clarithromycin should be avoided in case of resistance.

Development of the rat efferent vestibular system on the ground and in microgravity

We investigated whether plastic changes occurred in the organization of the vestibular efferent network in the rat utricle during a 17-day episode of microgravity, from postnatal (PN) day 8 to PN23, and on return to earth on PN25. We also determined the normal pattern of efferent development from birth to PN25. Immunofluorescence experiments were performed with a specific biochemical marker of the efferent system, the calcitonin gene-related peptide (CGRP), and vibratome sections of the utricles were analyzed by laser scanning confocal microscopy. At birth, a few efferent fibers were detected beneath the sensory epithelium. These then massively invaded the epithelium between PN2 and PN4. At the time of launch, PN8, most fiber paths in the utricular epithelium, after following transient courses (towards the epithelial surface for example) returned to the base and were stabilized in the lower part of the epithelium, in which they established synaptic contacts with sensory cells, except at a few immature locations. The main difference between this stage (on PN8) and subsequent more mature stages was the lower density of fibers and synapses in the utricle. The maturation of the vestibular efferent system was similar in microgravity and on the ground. Thus, maturation of the efferent system between PN8 and PN23 was not sensitive to a change in gravitational environment. These results suggest that periods of microgravity at earlier stages are required to identify critical periods in peripheral vestibular system development.

Distal superior cerebellar artery aneurysm presenting with cerebellar infarction: report of two cases

SUMMARY

We report two cases of aneurysm of the distal branches of the superior cerebellar artery presenting with cerebellar infarction. In both cases, the diagnosis required close correlation of the findings from different imaging techniques, as catheter angiography failed to opacify the lesions. In one patient endovascular parent vessel occlusion was performed, whereas in the second patient the aneurysm thrombosed spontaneously. We describe the clinical and radiologic presentation of these aneurysms and discuss their pathogenesis, diagnosis, and treatment.

Procalcitonin in children admitted to hospital with community acquired pneumonia

AIMS

To assess the sensitivity, specificity, and predictive value of procalcitonin (PCT) in differentiating bacterial and viral causes of pneumonia.

METHODS

A total of 72 children with community acquired pneumonia were studied. Ten had positive blood culture for Streptococcus pneumoniae and 15 had bacterial pneumonia according to sputum analysis (S pneumoniae in 15, Haemophilus influenzae b in one). Ten patients had Mycoplasma pneumoniae infection and 37 were infected with viruses, eight of whom had viral infection plus bacterial coinfection. PCT concentration was compared to C reactive protein (CRP) concentration and leucocyte count, and, if samples were available, interleukin 6 (IL-6) concentration.

RESULTS

PCT concentration was greater than 2 microg/l in all 10 patients with blood culture positive for S pneumoniae; in eight of these, CRP concentration was above 60 mg/l. PCT concentration was greater than 1 microg/l in 86% of patients with bacterial infection (including Mycoplasma and bacterial superinfection of viral pneumonia). A CRP concentration of 20 mg/l had a similar sensitivity but a much lower specificity than PCT (40% v 86%) for discriminating between bacterial and viral causes of pneumonia. PCT concentration was significantly higher in cases of bacterial pneumonia with positive blood culture whereas CRP concentration was not. Specificity and sensitivity were lower for leucocyte count and IL-6 concentration.

CONCLUSIONS

PCT concentration, with a threshold of 1 microg/l is more sensitive and specific and has greater positive and negative predictive values than CRP, IL-6, or white blood cell count for differentiating bacterial and viral causes of community pneumonia in untreated children admitted to hospital as emergency cases.

High levels of resistance to metronidazole and clarithromycin in Helicobacter pylori strains in children

The aim of the study was to evaluate the prevalence of resistance to amoxicillin, metronidazole, and clarithromycin before treatment of Helicobacter pylori infection in children and to assess the evolution of resistance with time. The study was carried out between 1994 and 1999 with 150 H. pylori-positive children through gastric culture (antimicrobial susceptibility) and histology. All cultured H. pylori strains were sensitive to amoxicillin, 64 (43%) were resistant to metronidazole, 32 (21%) were resistant to clarithromycin, and 14 (9%) were resistant to both metronidazole and clarithromycin. The overall prevalence of resistance to metronidazole and clarithromycin did not change significantly with time. The study highlights the generalized high-level and stable metronidazole and clarithromycin resistance of H. pylori strains from children.

[Epidemiology of nosocomial infections in pediatrics]

The overall incidence of nosocomial infections (NI) in pediatrics ranges between 2.3% to 12.6%. They have great variations according to age (7-12% under 1 year of age vs 1.5-4% after ten years of age), and the nature of the unit (3-26% in intensive care units vs 1-4% in general pediatrics). The main sites of infection are in children gastrointestinal infections (10-35% of NI) and bacteremia (10-23% of NI) whereas in adults urinary tract infections (31.7 to 35%) and respiratory infections (19 to 25%) are the most frequent. Viruses represent 22-27% of the isolated pathogens, and Gram positive cocci 31-50% (half of them are coagulase negative staphylococci). The most frequent Gram negative bacilli are Pseudomonas aeruginosa (9-15%), E. coli (6-16%) and Klebsiella pneumoniae (3-5%). Candida represent 3% of isolated pathogens in NI. The proportion of methicilline-resistant Staphylococcus aureus is lower in children than in adults. The prevalence of methicillin resistance of CNS is however close to that observed in adults, as is the multiresistance of Gram negative bacilli (Klebsiella). Candida infections seem an emerging problem in paediatrics. These results underline the necessity to limit the antimicrobial therapy in children as in adults.

Oestradiol decreases rat apolipoprotein AI transcription via promoter site B

Oestrogens protect against ischaemic heart disease in the post-menopausal female by increasing serum concentrations of apolipoprotein (apo) AI and the abundance of high-density lipoprotein particles. In men and experimental male animals, the administration of oestrogen has variable effects on apo AI expression. As the major mode of oestrogen action on target genes involves regulating promoter activity and hence transcription, oestrogen is expected to alter transcription of the apo AI gene. To test this hypothesis, the effect of 17beta-oestradiol (E(2)), on rat apo AI promoter activity in male hepatoma HuH-7 cells, was tested by co-transfecting a reporter template, pAI.474.CAT containing-474 to-7 of the rat apo AI promoter and an oestrogen receptor (ER) expression vector, pCMV-ER. Transfected cells exposed to E(2) showed a dose-dependent decrease in chloramphenicol acetyltransferase (CAT)-activity, with a maximum 91+/-1.5% reduction at 1 microM E(2). Deletional analysis of the promoter localized the inhibitory effect of ER and E(2) to site B (-170 to-144) with an adjacent 5' contiguous motif, site S (-186 to-171) acting as an amplifier. HuH-7 cell nuclear extracts showed binding activities with both sites S and B, but recombinant human ER did not. Furthermore, nuclear extracts from E(2)-treated HuH-7 cells showed weaker binding activity to site B, but not to site S. In summary, the inhibitory effect of ER and E(2) on rat apo AI gene activity is mediated by a promoter element, site B. This inhibitory effect arises from a mechanism that does not involve direct ER binding to the B-element. The conclusion that E(2) inhibits apo AI transcription was confirmed in vivo. Treatment of male adult Sprague-Dawley rats with up to 200 microg E(2) for 7 days decreased apo AI protein and hepatic mRNA by 72+/-21% and 68+/-1.4% respectively. Results of 'run-on' transcription of the apo AI gene in isolated hepatic nuclei showed a 55% decrease in hormone-treated male rats. These findings suggest that E(2) exerts primarily an inhibitory effect within male hepatic nuclei.

Postnatal developmental changes in AMPA and NMDA receptors in the rat vestibular nuclei

Changes in the expression of the AMPA receptor subunits GluR1-4 and of the NMDA receptor subunits NR1, NR2A-D were investigated in the developing rat medial and lateral vestibular nuclei. Analyses were performed using nonradioactive in situ hybridization and immunoblotting with subunit-specific antibodies. During the postnatal development, glutamatergic receptor subunits were differentially expressed in the vestibular nuclei. The level of expression of GluR1, GluR4 and NR1 subunits was higher in the developing brain as compared to the adult. We observed a gradual increase in GluR2/3, NR2A, NR2B and NR2C levels of expression in the medial and lateral vestibular nuclei during the first 3 weeks of postnatal development. In situ hybridization results were consistent with immunoblot analyses. The differential expression of AMPA and NMDA receptor subunits in immature vestibular neurons is consistent with changes in glutamate receptor properties. This may be related to the postsynaptic regulation of receptor subunits associated with the synaptic plasticity of the vestibular neuron connections during specific sequences of postnatal development.

[Helicobacter pylori infection in children]

Helicobacter pylori infection is frequent in children. Its incidence in Europe, around 6% in children aged 6-16 years, varies with the socio-economic level and nutritional status. It may reach 46% in Africa and up to 75% in some institutions. Clinical manifestations debated. Vomiting, dyspepsia and acute pain related to ulcer disease may undisputedly be linked to H. pylori, whereas its role in chronic abdominal has yielded contradictory reports. Direct isolation of the bacterium is classically done through perendoscopic antral biopsies followed by culture and histology. Non-invasive diagnosis methods get a wider use in children. Serodiagnosis is reproducible and easy only in older children. The 13C-urea breath test is sensitive and specific, and seems perfectly suitable in pediatrics. The H. pylori stool antigen test for the detection of infection seems promising but not yet of current clinical use. Triple therapy using amoxicillin-clarithromycin (or metronidazole or tinidazole) and anti-secretory agents is recognised as the most efficient association.

Heat-shock protein 90: intrinsic peptidase activity and in vitro long-term self-processing

When tested on Suc-Leu-Leu-Val-Tyr-MCA as substrate, purified full-length hsp90 displays a low "chymotrypsin-like" peptidase activity which is activated by Ca++ and Mg++ ions. On the other hand, using long-term in vitro experiments, we demonstrate the ability of hsp90 to convert into a 73 kDa truncated product. This autocatalytic degradation proceeds from the C-terminal end of the full-length hsp90 and shifts the oligomers toward monomeric truncated forms. This corresponds to an intermolecular process as addition of exogenous 73 kDa product speeds up the maturation kinetics. The peptidase activity is enhanced in the 73 kDa product and is sensitive to peptide aldehyde inhibitors but only partially to lactone compounds. The degradation process itself presents a great degree of similarity with the peptidase activity toward either the inhibitors or the tested ions. Neither 20S proteasome nor m-calpain are responsible for the observed activities. Indeed, the self-processing is a consequence of the peptidase activity which appears to be an intrinsic property of the chaperone. The functional importance of these findings is discussed.

Effect of prior exposure to Chlamydia pneumoniae, Helicobacter pylori, or cytomegalovirus on the degree of inflammation and one-year prognosis of patients with unstable angina pectoris or non-Q-wave acute myocardial infarction

Inflammation and chronic infections may be important features in the pathogenesis of acute coronary syndromes. We describe 6 systemic markers of inflammation in patients with unstable angina or non-Q-wave myocardial infarction and the relations between these markers, seropositivity to chronic infections, and prognosis. C-reactive protein (CRP), serum amyloid A protein (SAA), fibrinogen, interleukin-6 (IL-6), neopterin, procalcitonin, and serum antibody levels to Chlamydia pneumoniae, Helicobacter pylori, and cytomegalovirus were measured on admission and 48 hours later. One-year clinical follow-up was performed. Plasma levels of acute phase reactants were all elevated on admission and increased further at 48 hours: CRP from 10.1 +/- 2.1 mg/L at baseline to 26.6 +/- 5.1 mg/L at 48 hours (p <0.001); SAA from 27.3 +/- 8.5 to 93.1 +/- 23.2 mg/dl (p <0.005); fibrinogen from 3.2 +/- 0.1 to 3.8 +/- 0.1 g/L (p <0.0001); whereas initial high levels of IL-6 tended also to increase from 9.8 +/- 2 to 15.3 +/- 3.1 pg/ml (p = NS). In contrast, neopterin and procalcitonin remained unchanged. We found no association between levels of each inflammatory marker and the serologic status. Furthermore, levels of inflammatory proteins in patients seronegative to all 3 agents were comparable to those of patients seropositive to 2 or 3 infectious agents. The composite end points of death, myocardial infarction, recurrent angina, or revascularization at 1-year follow-up did not differ according to the serologic status. Thus, in patients with acute coronary syndromes, the acute phase proteins increased over the first 2 days of hospitalization. This initial inflammatory reaction as well as the 1-year clinical outcome did not differ according to the initial serologic status of Chlamydia pneumoniae, Helicobacter pylori, or cytomegalovirus.

Reduced lung diffusion capacity after Mycoplasma pneumoniae pneumonia

BACKGROUND

Mycoplasma pneumoniae is a frequent but underdiagnosed cause of community-acquired pneumonia (CAP) in children, and appropriate macrolide treatment is often given late. The aim of this work was to estimate the frequency of pulmonary involvement in children 6 months after a clinical episode of Mycoplasma CAP.

METHODS

We measured carbon monoxide diffusion capacity (TLCO) and conducted spirometric tests in 35 children without asthma or chronic lung disease (ages 4.5 to 15 years), 6 months and 1 year after acute CAP caused by M. pneumoniae (23 children), pneumococci (5 children) or viruses (7 children). Only 11 of 23 patients with M. pneumoniae CAP required hospitalization, whereas all the patients with pneumococcal or viral pneumonia were admitted to hospital.

RESULTS

Lung volumes and spirometric tests were normal for all children. TLCO was normal 6 months after pneumococcal or viral pneumonia (87 to 112% of expected values for height and sex). After acute M. pneumoniae CAP, 11 of 23 patients (48%) had TLCO values <80% of the expected value. The extent of change in lung diffusion capacity was correlated with the delay to diagnosis and treatment: TLCO was low in 8 of 11 patients given macrolide treatment 10 days or more after the onset of acute symptoms vs. only 3 of 10 patients given appropriate treatment in the first 10 days. TLCO was low in 7 of 7 who received macrolide therapy for <2 weeks. TLCO had increased slightly after 1 year in the 5 patients retested after a new course of macrolide treatment. TLCO reached the lower normal range in 2 patients controlled after 3 years.

CONCLUSIONS

The abnormal TLCO values suggest that some children with Mycoplasma pneumonia have reduced pulmonary gas diffusion after recovery from the illness. The reduction is related to delay and short macrolide therapy.