Persistent Bacteremia in the Absence of Defined Intravascular Foci: Clinical Significance and Risk Factors

The clinical significance of and the risk factors for persistent bacteremia were assessed in 299 episodes. Persistent bacteremia was defined as at least two positive blood cultures obtained on different calendar days during the same infectious episode. Short-term bacteremia was defined as positive blood cultures solely on the first day of the infectious episode. A total of 4,277 episodes of bloodstream infections were detected, of which 299 episodes (7%) were persistent bacteremia. The following were independent risk factors were for persistent bacteremia: burns, presence of a central vascular catheter, cirrhosis, infections caused by Salmonella spp., polymicrobial infections, and inappropriate empirical antibiotic treatment. Irrespective of the source of infection, the presence of a central vascular catheter was correlated with an increased risk for persistent bacteremia. Mortality among patients with persistent bacteremia was 50%, compared to 35% among patients with short-term bacteremia. Because of the high mortality associated with persistent bacteremia, a thorough search for the source of infection is essential to ensure timely and appropriate therapy.

Endothelin-converting enzyme-1 (ECE-1) is a downstream target of the homeobox transcription factor Nkx2-5

The homeobox transcription factor Nkx2-5 and the zinc metalloprotease endothelin-converting enzyme-1 (ECE-1) are essential for cardiac development. Here, we demonstrate for the first time a functional link between Nkx2-5 and ECE-1. In transiently transfected rat H9c2 cardiomyoblasts, the alternative promoters specific for ECE-1a, ECE-1b, and ECE-1c are activated by Nkx2-5 coexpression. Lack of a consensus sequence for Nkx2-5 binding within the ECE-1c promoter and mutational analyses of Nkx2-5 consensus sequences identified in the ECE-1a and ECE-1b promoters, respectively, reveal an indirect mechanism of activation that is supported by gel shift assays. Furthermore, we have evidence of an additional direct activation mechanism of the ECE-1b promoter by Nkx2-5. With the use of RNase protection assay, Northern blot, and real-time PCR, the activating effect of Nkx2-5 on mRNA expression of ECE-1 isoforms was confirmed in the chromatin context of H9c2 and endothelial EA.hy926 cells, respectively, by stable Nkx2-5 overexpression. The interaction presented in this work provides a possible explanation for distinct phenotypic aspects of patients carrying mutations in the Nkx2-5 gene and may also be of significance for the pathophysiology of heart failure.

[Severe ethanol-intoxication mimics symptoms of intracranial hypertension]

We report on a patient intoxicated with ethanol, who was found unconscious with fixed dilated pupils, deviation of eyes, absent cough and corneal reflexes, with her arms in decerebrate posture. Because of an orbital haematoma a traumatic intracranial hemorrhage with elevated intracranial pressure and compression or concussion of the brain stem was suspected. A CT-scan of the head did not reveal an intracranial mass or any radiographic signs of intracranial hypertension. Drug screening, blood gas analysis and other laboratory tests as well anamnestic data were not indicative of other intoxications or a metabolic decompensation. These unusual neurological findings were caused by a life-threatening ethanol intoxication with a blood-alcohol concentration of 700 mg/dl (151.8 mmol/l). The patient was extubated after several hours of mechanical ventilation in the intensive care unit and was discharged to a regular ward on the following day.

[The Lazarus phenomenon. Spontaneous return of circulation after unsuccessful intraoperative resuscitation in a patient with a pacemaker]

We present a case of spontaneous recovery after failed intraoperative cardiopulmonary resuscitation in a patient with a cardiac pacemaker. Of the various mechanisms discussed in the literature, that which seems most relevant in our case of a Lazarus phenomenon, is that of impeded venous return in the course of positive pressure ventilation and hypovolemia.With the disconnection of ventilation, passive cardiac filling combined with electrical stimulation due to the cardiac pacemaker may have caused spontaneous myocardial electrical activity. Corresponding to previous authors,we recommend continued monitoring for 10 min after cessation of cardiopulmonary resuscitation. In addition, we propose a further attempt by disconnecting ventilation and external myocardial stimulation in the case of unresponsiveness to resuscitation efforts.

Therapeutic evaluation of free and nanocapsule-encapsulated atovaquone in the treatment of murine visceral leishmaniasis

The activities of free atovaquone (ATV) and of poly(D,L-lactide) nanocapsules loaded with the drug, in the treatment of mice with visceral leishmaniasis caused by Leishmania infantum, were compared. Each mouse was infected intravenously with 2x10(7) promastigotes, on day 0. On days 15, 17 and 19, most of the infected mice were treated either with free ATV, in a dimethylsulphoxide/cremophor/water mixture, or with the ATV-loaded nanocapsules (at, respectively, 0.2-1.6 and 0.125-1.0 mg ATV/kg, on each treatment day). The rest of the mice were left untreated, as controls. All the mice were killed on day 21 and dissected so that their livers and spleens could be weighed. The liver parasite burdens, evaluated using the Stauber method, indicated that the ATV-loaded nanocapsules were significantly more effective than the free drug. In nanocapsules, for example, a total dose of 3.0 mg ATV/kg reduced liver burdens by 71.3%, whereas treatment with a higher total dose of the free drug (4.8 mg/kg) only cut the number of liver parasites by 34.4%. The dose-response data indicated that livers would have been cleared of parasites if the nanocapsule preparation had been given as three doses each equivalent to 3 mg ATV/kg, whereas the maximum suppression possible with the free drug would have been about 61%, whatever the dose.

[Aneurysm of the subclavian artery after operatively corrected coarctation of the aorta: 20 years of follow-up and review of the current literature]

We report of long-term follow-up of a combined fusiform aneurysm of the right subclavian artery extending to the thyreocervical trunk (3.2 x 2.8 x 2.2 cm (width x height x depth)) in a 33-year old patient. As a newborn, the clinical diagnosis of an aortic isthmus stenosis was made without need for intervention at this stage. Further development of the child remained unremarkable until the age of eleven years when he experienced dizziness after sporting activities. Due to clinically proven progress, cardiac catheterization was performed and confirmed the initial diagnosis of a juxtaductale stenosis of the aortic isthmus, which was operated thereafter with an end-to-end anastomosis. Furthermore, an aneurysm of the right subclavian artery was revealed. Since then, non-invasive routine follow-up showed no significant worsening of this aneurysm, which extends to the thyreocervical trunk. The patient has been event free and completely asymptomatic. This case report illustrates the more than twenty years of follow-up of an asymptomatic combined fusiform aneurysm of the subclavian artery and thyreocervical trunk and provides a review of the literature on this topic.

Antibiotic prophylaxis of bacterial infections in cirrhotic inpatients: a meta-analysis of randomized controlled trials

BACKGROUND

Antibiotic prophylaxis has been reported to decrease bacterial infections and fatality rates in inpatients with cirrhosis. We performed a systematic review to evaluate the efficacy of antibiotic prophylaxis in inpatients with cirrhosis, regardless of the underlying risk factors that led to hospital admission.

METHODS

A comprehensive literature search strategy was performed including the Cochrane Library, Embase, Medline, a manual search of bibliographic references, and contacting the authors of each included trial. We included any randomized clinical trial comparing different types of antibiotic prophylaxis with placebo or no intervention in inpatients with cirrhosis. Two reviewers independently applied the selection criteria to all identified references, appraised the methodological quality of each trial and extracted the relevant data. Relative risks and 95% confidence intervals were estimated using the fixed effect model. A test of heterogeneity and a funnel plot were performed and an intention-to-treat approach was used for the outcome measures.

RESULTS

Nineteen randomized trials were identified, 13 of which were included in the review. A significant beneficial effect on mortality (RR: 0.70; 95% CI: 0.56, 0.89) and prevention of bacterial infections (RR: 0.39; 95% CI: 0.32, 0.48) was observed, regardless of the underlying risk factors. Few adverse events were reported and there was no heterogeneity between studies. We identified a funnel plot asymmetry for the included trials.

CONCLUSIONS

Antibiotic prophylaxis for inpatients with cirrhosis is efficacious in reducing the number of deaths and bacterial infections regardless of the underlying risk factors.

Genetics of arrhythmogenic right ventricular cardiomyopathy--status quo and future perspectives

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a primary myocardial disorder of unknown origin. In recent years, the disease has been recognized as a major cause of ventricular tachyarrhythmias and sudden cardiac death in young patients with apparently normal hearts. Although characteristic structural, imaging and electrocardiographic features are included in a proposed catalogue of diagnostic criteria, the correct diagnosis of ARVC often remains difficult. Much effort has been undertaken to enlarge the knowledge on pathophysiological mechanisms of the disease. The role of molecular genetics for the pathogenesis of ARVC is discussed in the following review. On the basis of linkage analyses in large families affected by ARVC, there is growing evidence for genetic alterations in ARVC, which, in the majority of chromosomal loci (seven) reported so far, follow a Mendelian autosomal-dominant pattern of inheritance with variable penetrance and polymorphic phenotype. Besides this, two autosomal-recessive forms of ARVC are known. These can be differentiated from the autosomal-dominant forms not only in terms of the mode of inheritance but also as to their specific phenotype: patients with Naxos disease exhibit characteristic hair and skin abnormalities and experience a more severe course of disease. Patients with another autosomal-recessive form display the typical but milder signs of ARVC together with opacifications of the crystalline lens. So far, two mutations in cardiac genes responsible for the development of ARVC have been reported. A homozygous two base pair deletion in the gene encoding for the cytoskeletal protein plakoglobin seems to account for the evolution of Naxos disease. The second mutation affecting the cardiac ryanodine receptor gene was found in patients with ARVC-2. Routine genetic testing of patients or relatives with a suspected diagnosis of ARVC is not available at present but may become the future gold standard with potential implications for a better understanding of the pathogenesis and management of the disease.

Atovaquone-loaded nanocapsules: influence of the nature of the polymer on their in vitro characteristics

Nanocapsules with atovaquone concentration of 1,000 micrograms/ml were prepared according to the interfacial deposition technique using different polymers: poly- epsilon -caprolactone (PECL), poly(lactic acid) (PLA) and poly(lactic-co-glycolic acid) (PLAGA). The following characteristics of nanoparticles were determined: percentage of encapsulation of atovaquone, percentage of encapsulation of benzyl benzoate (BB), nanoparticle size, nanoparticle wall thickness, suspension pH, and in vitro stability. The different formulations showed similar characteristics: maximal percentage of encapsulation (100%), particle size of approximately 230 nm, neutral pH and wall thickness of approximately 20 nm. The type of polymer used was the main factor influencing stability, in decreasing order: PECL>PLA>PLAGA. No release of atovaquone or benzylbenzoate was noted with PECL nanoparticles over 4 months. Release of atovaquone (25.9%) was found with PLA nanoparticles at 4 months. Release of both atovaquone (18.9%) and benzylbenzoate (54.2%) was noted with PLAGA nanoparticles from the third month, indicating a disruption of the nanoparticle membrane.

Beta-lactam versus beta-lactam-aminoglycoside combination therapy in cancer patients with neutropaenia

BACKGROUND

Chemotherapy treated cancer patients are prone to neutropaenia and life-threatening infections. Early, empirical antibiotic treatment is therefore administered routinely to febrile neutropaenic patients. Currently, either beta-lactam-aminoglycoside combination treatment or beta-lactam monotherapy are recommended.

OBJECTIVES

We compared beta-lactam monotherapy versus beta-lactam-aminoglycoside combination therapy for cancer patients with fever and neutroepaenia.

SEARCH STRATEGY

We searched the Cochrane Cancer Network Register (searched July, 2000), the Cochrane Controlled Trials Register (Cochrane Library Issue 4, 2001), EMBASE (January 1980 to December 2000), LILACS (January 1982 to August 2001), MEDLINE (January 1966 to August 2001), and ICAAC conference proceedings (1995 to 2000). We scanned references of all included studies, pertinent reviews, and contacted the first author of each included trial and the pharmaceutical companies.

SELECTION CRITERIA

Randomised controlled trials comparing any beta-lactam antibiotic monotherapy to any combination of a beta-lactam and an aminoglycoside antibiotic, for the initial, empirical treatment of febrile neutropaenic cancer patients.

DATA COLLECTION AND ANALYSIS

Data concerning mortality, treatment failure (including treatment modifications), superinfections, adverse effects and study quality measures were extracted independently by two reviewers. Relative risks with their 95% confidence intervals (CI) were estimated. Outcomes were extracted by intention-to-treat analysis whenever possible.

MAIN RESULTS

Forty-six trials and 7642 patients were included. All cause mortality was the primary outcome assessed. For all mortality comparisons, no significant difference between monotherapy and combination therapy was seen, relative risk 0.85 (95% CI 0.72-1.02) for all studies combined. Treatment failure was the outcome reported in all included trials. No significant difference between study groups was shown for studies comparing the same beta-lactam, relative risk 1.12 (95% CI 0.96-1.29). A significant advantage to monotherapy was observed for studies comparing different beta-lactams, relative risk 0.86 (95% CI 0.80-0.93). Bacterial and fungal superinfections developed with similar frequencies in the monotherapy and combination treatment groups. Adverse events were significantly more common in the combination treatment group, relative risk 0.83, (95% CI 0.72-0.97). These included events associated with significant morbidity, primarily renal toxicity. Results were consistent for subgroup and sensitivity analyses.

REVIEWER'S CONCLUSIONS

We have shown an advantage to broad-spectrum beta-lactam monotherapy over beta-lactam-aminoglycoside combination therapy for febrile neutropaenia. This advantage comprises of 1) a similar, if not better, survival, 2) a significantly lower treatment failure rate, 3) comparable probability for secondary infections and, 4) most importantly, a lower rate of adverse events associated with significant morbidity. Monotherapy can be regarded, therefore, as the standard of care for febrile neutropaenic patients.

Optic neuritis complicating west nile virus meningitis in a young adult

A case of West Nile virus (WNV) infection with meningitis and optic neuritis in a 28-year-old man is presented. The patient had a number of unusual clinical and laboratory findings that broadened the differential diagnosis. The emergence of WNV infection in southern Europe and North America calls for increased awareness of physicians to this clinical entity.

Large angle elastic alpha scattering on a N=Z nucleus above A=40

Scattering of alpha particles from 44Ti, the lightest unstable alpha-particle nucleus above A=40, has been measured at backward angles. The "anomalous" order-of-magnitude enhancement that is characteristic of 40Ca and other light alpha-particle nuclei is not observed. Instead, the backward yield is similar to that observed for other nuclei heavier than 40Ca, and is well described with average optical model parameters.

Predictors of complications in acute type B aortic dissection

OBJECTIVES

Medical treatment is generally advocated for patients with acute type B aortic dissection without complications. The objective of this retrospective analysis was to determine whether there are any initial findings that can help predict the long-term course of the disease.

METHODS

Case records of the 130 patients treated for type B aortic dissection between 1988 and 1997 were reviewed; 41 (31%) were operated on in the acute phase (<14 days), 31 (24%) were operated on in the chronic phase and 58 (45%) were treated medically.

RESULTS

Overall acute mortality was 10.8%; 22% for patients operated on in the early phase and 5.6% for medically treated patients. Age (P=0.002), persistent pain (P=0.01) and malperfusion (P=0.001) were significant independent predictors of the need for surgery. Paraplegia/para paresis (P=0.0001), leg ischaemia (P=0.003), pleural effusion (P=0.003), rupture (P=0.0001), shock (P=0.0001), age (P=0.003), cardiac failure (P=0.002) and aortic diameter >4.5 cm (P=0.002) were significant predictors of poor survival. Age and shock also emerged as independent risk factors. Patients without malperfusion (P=0.0001), pleural effusion (P=0.003), rupture (P=0.0001) and shock (P=0.0001) had a significantly better event-free survival (freedom from repeat surgery and death). The actuarial survival rate for high-risk patients (malperfusion, rupture, shock) was 62% at 1 year and 40% at 5 years; the corresponding values for low-risk patients were 94 and 84%, respectively.

CONCLUSIONS

Rupture, shock and malperfusion are significant predictors of poor survival in patients with acute type B aortic dissection.

Characterisation of atovaquone resistance in Leishmania infantum promastigotes

Atovaquone, an antiparasitic agent, could possibly represent an alternative therapy after relapse following classical treatment for visceral leishmaniasis. Atovaquone-resistant strains were selected in vitro by stepwise drug pressure to study the mechanism of resistance in Leishmania. Characteristics of a promastigote strain resistant to 250 microg/ml of atovaquone were compared with those of the wild type (WT) strain. Resistant strains were shown to have a high level of resistance (45 times). They were stable in drug-free medium for 6 months, and showed no cross-resistance with other antileishmanial drugs. Rhodamine uptake and efflux were studied. They were not modified in the resistant strain, indicating the absence of P-glycoprotein overexpession. The effect of atovaquone on membrane lipidic composition was determined in both WT and atovaquone-resistant promastigotes. Analysis of lipid composition of the atovaquone-resistant strain showed that sterol biosynthesis was decreased in atovaquone-resistant parasites. Cholesterol was found to be the major membrane sterol as opposed to the WT strain. Cholesterol, due to its ordering effect, could decrease membrane fluidity and subsequently block the passage of atovaquone through the membrane. Increased membrane cholesterol content and altered drug membrane fluidity resulted from possible decrease of ergosterol biosynthesis by atovaquone, incorporation of cholesterol by promastigotes in the culture medium, solubilisation of atovaquone by cholesterol and co-passage of the two compounds or influence of dimethylsulfoxide. These results indicate that different cellular alterations may participate in the resistant phenotype, by altering drug membrane permeability.

Expression of telomerase genes as potential marker of neoplastic changes

We conducted a quantitative analysis of TERT, TP1 and hTR mRNA expression in various types of endometrial hyperplasia in perimenopausal women, taking advantage of the real-time PCR assay. All women underwent hysterectomy for gynecological reasons. Endometrial dating was determined from the patomorphology of the endometrium and classified into endometrial hyperplasia: simplex, complex and atypica. Our data suggest that only hTR was observed in each normal and hyperplastic endometrium specimens, suggesting that this factor constitutively expressed in endometrium. The results obtained indicate that the expression activity of the TERT subunit changes but not significantly, depending on the stage of development of the hyperplasia.

Quantitative analysis of estrogen receptor mRNA in human endometrium throughout the menstrual cycle using a real-time reverse transcription-polymerase chain reaction assay

We conducted a quantitative analysis of ERalpha and ERbeta mRNA expression in normal human endometrium throughout the menstrual cycle in regular menstruating premenopausal women, taking advantage of this real-time PCR assay. Endometrial dating was determined from the histology of the endometrium and classified into: proliferative endometrium and secretory endometrium. Both ERalpha and ERbeta mRNA expression were detected in all endometrial samples at both proliferative and secretion phase. However ERalpha mRNA expression level was higher than that of ERbeta specially during proliferative phase. These results suggest that estrogenic effects occur predominantly through ERalpha than ERbeta.

Quantitative analysis of estrogen receptor-alpha and -beta and exon 5 splicing variant mRNA in endometrial hyperplasia in perimenopausal women

We used real-time reverse transcription-polymerase chain reaction (QRT-PCR) to detect wild-type ERalpha and ERbeta and their isoforms as well as exon 5 splicing variant mRNA ERalpha in various types of endometrial hyperplasia in perimenopausal women. Our data suggest that the exon 2 and 7 deletion ERalpha mRNA isoforms are present in endometrial tissue undergoing various hyperplastic states. Wild type ERbeta mRNA and their isoforms 2, 4, 5, 6 were observed in each type of assessed endometrial specimens, and ERalpha/delta5 was found only in hyperplasia complex group.

Differentiation strategies of alternative splicing variants mRNA estrogen receptor-alpha

From the clinical point of view recognizing the concentrations and type profile of isoforms could be of significant practical importance. The aim of the study is designed QRT-PCR reaction to assess profile of mRNA ER-alpha and their isoforms. Theoretical part of the study was made according to computer program and available Genbank database. To detect a isoform one of the primer was designed to hybridize within exon-border linked in alternative splicing. The study presents the differentiation strategies in isoforms coming about as the alternative splicing result. Designed oligonucleotide probes and primers allow to distinguish mRNA isoforms of ER-alpha and their quantification in assessed tissues.

In utero exposure to low doses of bisphenol A lead to long-term deleterious effects in the vagina

The origins of the "endocrine disrupter hypothesis" may be traced to reports on adolescent daughters born to women who had taken the highly potent synthetic estrogen, diethylstilbestrol, while pregnant, and who developed a rare form of vaginal cancer and adenocarcinoma. Bisphenol A (BPA) is an estrogenic chemical that is highly employed in the manufacture of a wide range of consumer products. Some observational studies have suggested that the amounts of BPA to which we are exposed could alter the reproductive organs of developing rodents. We examined the influence of BPA at low doses to address the questions of (a) whether in utero exposure affects the vagina of the offspring and (b) which mechanisms cause the toxic effects. Gravid Sprague-Dawley dams were administered either 0.1 (low dose) or 50 mg/kg per day BPA, the no observed effect level, or 0.2 mg/kg per day 17 alpha-ethinyl estradiol by gavage. Striking morphological changes were observed in the vagina of postpubertal offspring leading us to examine vaginal estrogen receptor (ER) expression because BPA binds to the ER alpha, which is important for growth of the vaginal epithelium. We show that the full-length ER alpha is not expressed during estrus in the vagina of female offspring exposed to either dose of BPA when compared to the control group, whereas ER alpha expression does not differ from the control group during the diestrus stage. ER alpha downregulation seems to be responsible for the observed altered vaginal morphology.

Evidence that the medial amygdala projects to the anterior/ventromedial hypothalamic nuclei to inhibit maternal behavior in rats

The maternal behaviors shown by a rat that has given birth are not shown by a virgin female rat when she is first presented with young. This absence of maternal behavior in virgins has been attributed to the activity of a neural circuit that inhibits maternal behavior in nulliparae. The medial amygdala and regions of the medial hypothalamus such as the anterior and ventromedial hypothalamic nuclei have previously been shown to inhibit maternal behavior, in that lesions to these regions promote maternal responding. Furthermore, we have recently shown that these and other regions, such as the principal bed nucleus of the stria terminalis, the ventral lateral septum, and the dorsal premammillary nucleus, show higher pup-induced Fos-immunoreactivity in non-maternal rats exposed to pups than during the performance of maternal behavior, indicating that they too could be involved in preventing maternal responsiveness. The current study tested whether the medial amygdala projects to the anterior/ventromedial hypothalamic nuclei in a neural circuit that inhibits maternal behavior, as well as to see what other brain regions could participate in this circuit. Bilateral excitotoxic lesions of the medial amygdala, or of the anterior/ventromedial hypothalamic nuclei, promoted maternal behavior. Unilateral medial amygdala lesions caused a reduction of pup-induced Fos-immunoreactivity in the anterior/ventromedial hypothalamic nuclei in non-maternal rats ipsilateral to the lesion, as well as in the principal bed nucleus of the stria terminalis, ventral lateral septum, and dorsal premammillary nucleus. Finally, unilateral medial amygdala lesions paired with contralateral anterior/ventromedial hypothalamic nuclei lesions promoted maternal behavior, although ipsilateral lesion placements were also effective.Together, these results indicate that the medial amygdala projects to the anterior/ventromedial hypothalamic nuclei in a neural circuit that inhibits maternal behavior, and that the principal bed nucleus of the stria terminalis, ventral lateral septum, and dorsal premammillary nucleus could also be involved in this circuit.