Clinical Presentations and Outcomes of Children in Canada With Recurrent Invasive Pneumococcal Disease From the IMPACT Surveillance Network.

BACKGROUND: Invasive pneumococcal disease due to Streptococcus pneumoniae can cause mortality and severe morbidity due to sepsis, meningitis and pneumonia, particularly in young children and the elderly. Recurrent invasive pneumococcal disease is rare yet serious sequelae of invasive pneumococcal disease that is associated with the immunocompromised and leads to a high mortality rate. METHOD: This retrospective study reviewed recurrent invasive pneumococcal disease cases from the Canadian Immunization Monitoring Program, ACTive (IMPACT) between 1991 and 2019, an active network for surveillance of vaccine-preventable diseases and adverse events following immunization for children ages 0-16 years. Data were collected from 12 pediatric tertiary care hospitals across all 3 eras of public pneumococcal conjugate vaccine implementation in Canada. RESULTS: The survival rate within our cohort of 180 recurrent invasive pneumococcal disease cases was 98.3%. A decrease of 26.4% in recurrent invasive pneumococcal disease due to vaccine serotypes was observed with pneumococcal vaccine introduction. There was also a 69.0% increase in the rate of vaccination in children with preexisting medical conditions compared with their healthy peers. CONCLUSION: The decrease in recurrent invasive pneumococcal disease due to vaccine-covered serotypes has been offset by an increase of non-vaccine serotypes in this sample of Canadian children.

Thin-Slice Pituitary MRI with Deep Learning-Based Reconstruction for Preoperative Prediction of Cavernous Sinus Invasion by Pituitary Adenoma: A Prospective Study.

BACKGROUND AND PURPOSE: Accurate radiologic prediction of cavernous sinus invasion by pituitary adenoma remains challenging. We aimed to assess whether 1-mm-slice-thickness MRI with deep learning-based reconstruction can better predict cavernous sinus invasion by pituitary adenoma preoperatively and to estimate the depth of invasion and degree of contact in relation to the carotid artery, compared with 3-mm-slice-thickness MRI. MATERIALS AND METHODS: This single-institution, prospective study included 67 consecutive patients (mean age, 53 [SD, 12] years; 28 women), between January and August 2020, who underwent a combined contrast-enhanced T1-weighted imaging protocol of 1-mm-slice-thickness MRI + deep learning-based reconstruction and 3-mm-slice-thickness MRI. An expert neuroradiologist who was blinded to the imaging protocol determined cavernous sinus invasion using the modified Knosp classification on 1-mm-slice-thickness MRI + deep learning-based reconstruction and 3-mm-slice-thickness MRI, respectively. Reference standards were established by the consensus of radiologic, intraoperative, pathologic, and laboratory findings. The primary end point was the diagnostic performance of each imaging protocol, and the secondary end points included depth of invasion and degree of contact in relation to the carotid artery. RESULTS: The diagnostic performance of 1-mm-slice-thickness MRI + deep learning-based reconstruction (area under the curve, 0.79; 95% CI, 0.69 - 0.89) in predicting cavernous sinus invasion by pituitary adenoma was higher than that of 3-mm-slice-thickness MRI (area under the curve, 0.61; 95% CI, 0.52-0.70; P < .001). One-millimeter-slice-thickness MRI + deep learning-based reconstruction demonstrated greater depth of invasion by pituitary adenomas from the medial intercarotid line than 3-mm-slice-thickness MRI (4.07 versus 3.12 mm, P < .001). A higher proportion of cases were in a greater degree of contact with the intracavernous ICA with 1-mm-slice-thickness MRI + deep learning-based reconstruction than with 3-mm-slice-thickness MRI (total encasement, 37.3% versus 13.4%, P < .001; >270°, 38.8% versus 16.4%, P < .001). CONCLUSIONS: Compared with 3-mm-slice-thickness MRI, 1-mm-slice-thickness MRI + deep learning-based reconstruction showed a higher diagnostic performance in preoperatively predicting cavernous sinus invasion by pituitary adenomas and demonstrated a greater depth and degree of contact in relation to the carotid artery.

Action observation for sensorimotor learning in surgery.

BACKGROUND: Acquiring new motor skills to learn complex movements and master the use of a diverse range of instruments is fundamental for developing expertise in surgery. Although aspects of skill development occur through trial and error, watching the performance of another individual (action observation) is an increasingly important adjunct for the acquisition of these complex skills before performing a procedure. The aim of this review was to examine the evidence in support of the use of action observation in surgery. METHODS: A narrative review of observational learning for surgical motor skills was undertaken. Searches of PubMed and PsycINFO databases were performed using the terms 'observational learning' OR 'action observation' AND 'motor learning' OR 'skill learning'. RESULTS: Factors such as the structure of physical practice, the skill level of the demonstrator and the use of feedback were all found to be important moderators of the effectiveness of observational learning. In particular, observation of both expert and novice performance, cueing attention to key features of the task, and watching the eye movements of expert surgeons were all found to enhance the effectiveness of observation. It was unclear, however, whether repeated observations were beneficial for skill learning. The evidence suggests that these methods can be employed to enhance surgical training curricula. CONCLUSION: Observational learning is an effective method for learning surgical skills. An improved understanding of observational learning may further inform the refinement and use of these methods in contemporary surgical training curricula.

Cystamine/cysteamine rescues the dopaminergic system and shows neurorestorative properties in an animal model of Parkinson's disease.

The neuroprotective properties of cystamine identified in pre-clinical studies have fast-tracked this compound to clinical trials in Huntington's disease, showing tolerability and benefits on motor symptoms. We tested whether cystamine could have such properties in a Parkinson's disease murine model and now provide evidence that it can not only prevent the neurodegenerative process but also can reverse motor impairments created by a 6-hydroxydopamine lesion 3 weeks post-surgery. Importantly, we report that cystamine has neurorestorative properties 5 weeks post-lesion as seen on the number of nigral dopaminergic neurons which is comparable with treatments of cysteamine, the reduced form of cystamine used in the clinic, as well as rasagiline, increasingly prescribed in early parkinsonism. All three compounds induced neurite arborization of the remaining dopaminergic cells which was further confirmed in ex vivo dopaminergic explants derived from Pitx3-GFP mice. The disease-modifying effects displayed by cystamine/cysteamine would encourage clinical testing.

Improvement of aortic valve stenosis by ApoA-I mimetic therapy is associated with decreased aortic root and valve remodelling in mice.

BACKGROUND AND PURPOSE: We have shown that infusions of apolipoprotein A-I (ApoA-I) mimetic peptide induced regression of aortic valve stenosis (AVS) in rabbits. This study aimed at determining the effects of ApoA-I mimetic therapy in mice with calcific or fibrotic AVS. EXPERIMENTAL APPROACH: Apolipoprotein E-deficient (ApoE(-/-) ) mice and mice with Werner progeria gene deletion (Wrn(Δhel/Δhel) ) received high-fat diets for 20 weeks. After developing AVS, mice were randomized to receive saline (placebo group) or ApoA-I mimetic peptide infusions (ApoA-I treated groups, 100 mg·kg(-1) for ApoE(-/-) mice; 50 mg·kg(-1) for Wrn mice), three times per week for 4 weeks. We evaluated effects on AVS using serial echocardiograms and valve histology. KEY RESULTS: Aortic valve area (AVA) increased in both ApoE(-/-) and Wrn mice treated with the ApoA-I mimetic compared with placebo. Maximal sinus wall thickness was lower in ApoA-I treated ApoE(-/-) mice. The type I/III collagen ratio was lower in the sinus wall of ApoA-I treated ApoE(-/-) mice compared with placebo. Total collagen content was reduced in aortic valves of ApoA-I treated Wrn mice. Our 3D computer model and numerical simulations confirmed that the reduction in aortic root wall thickness resulted in improved AVA. CONCLUSIONS AND IMPLICATIONS: ApoA-I mimetic treatment reduced AVS by decreasing remodelling and fibrosis of the aortic root and valve in mice.

MyD88 deficiency results in both cognitive and motor impairments in mice.

The myeloid differentiation primary response gene 88 (MyD88) product is the most common adaptor protein implicated in Toll-like and interleukin receptor (TIR) domain signaling and thus plays an important role in the innate immune system. Despite the fact that the MyD88-dependent pathway has emerged as an important player in cell death processes described in several animal models of neurodegenerative disorders, the contribution of this pathway to specific behavioral phenotypes has been largely ignored. To understand the full implication of this pathway, we tested MyD88(-/-) mice for both motor and cognitive functions in normal conditions. MyD88(-/-) mice displayed impaired spatial and working memory as detected by the Barnes maze, the water T-maze and the passive avoidance tests. Furthermore, MyD88(-/-) mice demonstrated hypolocomotion in the open-field and wheel activity systems, as well as impairments in motor coordination and balance using the pole test and the rotarod. Our findings shed light on behavioral alterations that are associated with the deletion of the MyD88 protein in physiological conditions. These behavioral effects should be taken into consideration when assessing the role of the MyD88-dependent pathway in various infectious and non-infectious conditions.

Depletion of WRN protein causes RACK1 to activate several protein kinase C isoforms.

Werner's syndrome (WS) is a rare autosomal disease characterized by the premature onset of several age-associated pathologies. The protein defective in patients with WS (WRN) is a helicase/exonuclease involved in DNA repair, replication, transcription and telomere maintenance. In this study, we show that a knock down of the WRN protein in normal human fibroblasts induces phosphorylation and activation of several protein kinase C (PKC) enzymes. Using a tandem affinity purification strategy, we found that WRN physically and functionally interacts with receptor for activated C-kinase 1 (RACK1), a highly conserved anchoring protein involved in various biological processes, such as cell growth and proliferation. RACK1 binds strongly to the RQC domain of WRN and weakly to its acidic repeat region. Purified RACK1 has no impact on the helicase activity of WRN, but selectively inhibits WRN exonuclease activity in vitro. Interestingly, knocking down RACK1 increased the cellular frequency of DNA breaks. Depletion of the WRN protein in return caused a fraction of nuclear RACK1 to translocate out of the nucleus to bind and activate PKCdelta and PKCbetaII in the membrane fraction of cells. In contrast, different DNA-damaging treatments known to activate PKCs did not induce RACK1/PKCs association in cells. Overall, our results indicate that a depletion of the WRN protein in normal fibroblasts causes the activation of several PKCs through translocation and association of RACK1 with such kinases.

Dopamine D1 receptor-mediated aggregation of N-terminal fragments of mutant huntingtin and cell death in a neuroblastoma cell line.

Huntington's disease (HD) is an inherited neurodegenerative disorder caused by abnormal CAG repeat expansion in the IT15 gene encoding huntingtin protein (htt). Mutated htt is predicted to acquire toxic properties in specific brain regions. For instance, striatal neurons expressing dopamine receptors predominantly degenerate in HD patients. Although the basis of this specific vulnerability remains unclear, a great deal of evidence has documented the ability of the dopamine system to modulate the toxicity of expanded htt. To investigate the relationship between dopamine receptors and expanded htt, we transfected enhanced green fluorescent proteins (EGFP) tagged to normal (25 CAG) or mutant (103 CAG) htt in SK-N-MC neuroblastoma cells that endogenously express D1 receptors. Forming nuclear and cytoplasmic aggregates, mutant htt-EGFP was toxic to cells beyond 24 h post-transfection. Remarkably, low doses of a selective D1 receptors agonist or forskolin, an activator of adenylate cyclase, accelerated the formation of mutant htt nuclear aggregates, whereas the number of cytoplasmic aggregates was decreased. These effects were associated with a minor increase in cell death. Understanding the functional bases of these effects may further elucidate the role of dopamine receptors signaling in the complex pathophysiology of HD.

[New trends in pediatric endocarditis]. / Nuevas tendencias de la endocarditis pediátrica.

OBJECTIVES: To evaluate the epidemiology, etiology and outcome of endocarditis in a cohort of pediatric patients and to compare the main characteristics with our previous experience. MATERIAL AND METHODS: Patients aged less than 18 years of age diagnosed with endocarditis at the Sainte-Justine Hospital, University of Montreal between 1-1986 and 12-2000 were studied. The recent case series was compared with our previous experience from 1960-1985. RESULTS: Fifty-six children with endocarditis were included in the 1986-2000 series: 35 children with congenital heart disease, 15 with serious underlying disease and six healthy children. The mean age was 7 years and 10 months. Fifty-four percent of the patients were boys. The incidence of endocarditis increased from 1.5 cases/year in the 1986-2000 series to 4 cases/year in the 1986-2000 series. In the 1986-2000 series, 10 (17.9 %) patients had a central catheter. Sixteen (28.6 %) patients had a vascular prosthesis. Blood cultures were positive in 50 patients (89 %): Streptococci were found in 48 % of the patients and Staphylococci in 34 %. Echocardiography was positive in 36 of 55 patients (65.4 %). All children were treated with intravenous antibiotics for a mean of 43 +/- 15 days. There were no recurrences. Significant morbidity developed in 26 patients (46 %). Embolic phenomena were seen in 11 children (20 %). Twelve patients (21 %) needed surgery. Of the six healthy children, five developed complications. Overall, seven children (12.5 %) died; all were older than 6 years of age. Comparing our experience from 1960-1985 with that from 1986-2000 revealed that morbidity decreased from 85.7 % to 46.4 % and mortality decreased from 27 % to 12.5 %. CONCLUSIONS: Physicians must recognize that children with underlying immunodeficiency and those with central catheters have an increased risk of endocarditis. Healthy children with endocarditis have a greater risk of complications. Morbidity and mortality due to endocarditis has diminished considerably in recent years.

Nuevas tendencias de la endocarditis pediátrica / New trends in pediatric endocarditis

Objetivos: Evaluar la epidemiología, los agentes etiológicos y la evolución de la endocarditis en una serie de pacientes pediátricos y comparar las principales características a nuestra experiencia anterior. Material y métodos: Pacientes menores de 18 años diagnosticados de endocarditis en el CHU Sainte-Justine de Montréal, entre enero de 1986 y diciembre de 2000. La serie reciente se ha comparado con nuestra experiencia anterior de 1960-1985. Resultados: En la serie actual se incluyeron 56 niños con endocarditis: 35 niños con cardiopatía congénita, 15 con otras enfermedades graves y 6 niños sanos. La edad media fue 7 años y 10 meses. El 54 % de los casos eran varones. La incidencia de endocarditis aumentó de 1,5 a 4 casos/año, en la primera frente a la segunda serie, respectivamente. En la serie actual, 10 pacientes (17,9 %) tenían un catéter. Un total de 16 pacientes (28,6 %) tenían diferentes prótesis vasculares. Los hemocultivos fueron positivos en 50 pacientes (89 %): Streptococcus representaba el 48 % y Staphylococcus el 34 % de los casos. La ecocardiografía fue positiva en 36 de 55 pacientes (65,4 %). Todos los pacientes fueron tratados con antibióticos intravenosos, una media de 43 ± 15 días. No hubo ninguna recurrencia. Se presentaron complicaciones importantes en 26 pacientes (46 %). Se observaron fenómenos embólicos en 11 niños (20 %). Doce pacientes (21 %) necesitaron cirugía. De los 6 niños sanos, cinco presentaron complicaciones. En total, 7 niños (12,5 %) murieron, todos eran mayores de 6 años. Comparando nuestra experiencia de 1960-1985 a 1986-2000, las complicaciones y la mortalidad han disminuido, del 85,7 al 46,4 % y del 27 al 12,5 %, respectivamente. Conclusiones: El médico debe conocer que los niños con inmunodeficiencia o con catéteres tienen un riesgo aumentado de endocarditis. Los niños sanos con endocarditis presentan mayor riesgo de complicaciones. Las complicaciones y la mortalidad han disminuido considerablemente en los últimos años

Objectives: To evaluate the epidemiology, etiology and outcome of endocarditis in a cohort of pediatric patients and to compare the main characteristics with our previous experience. Material and methods: Patients aged less than 18 years of age diagnosed with endocarditis at the Sainte-Justine Hospital, University of Montreal between 1-1986 and 12-2000 were studied. The recent case series was compared with our previous experience from 1960-1985. Results: Fifty-six children with endocarditis were included in the 1986-2000 series: 35 children with congenital heart disease, 15 with serious underlying disease and six healthy children. The mean age was 7 years and 10 months. Fifty-four percent of the patients were boys. The incidence of endocarditis increased from 1.5 cases/year in the 1986-2000 series to 4 cases/year in the 1986-2000 series. In the 1986-2000 series, 10 (17.9 %) patients had a central catheter. Sixteen (28.6 %) patients had a vascular prosthesis. Blood cultures were positive in 50 patients (89 %): Streptococci were found in 48 % of the patients and Staphylococci in 34 %. Echocardiography was positive in 36 of 55 patients (65.4 %). All children were treated with intravenous antibiotics for a mean of 43 ± 15 days. There were no recurrences. Significant morbidity developed in 26 patients (46 %). Embolic phenomena were seen in 11 children (20 %). Twelve patients (21 %) needed surgery. Of the six healthy children, five developed complications. Overall, seven children (12.5 %) died; all were older than 6 years of age. Comparing our experience from 1960-1985 with that from 1986-2000 revealed that morbidity decreased from 85.7 % to 46.4 % and mortality decreased from 27 % to 12.5 %. Conclusions: Physicians must recognize that children with underlying immunodeficiency and those with central catheters have an increased risk of endocarditis. Healthy children with endocarditis have a greater risk of complications. Morbidity and mortality due to endocarditis has diminished considerably in recent years

The Ask-Upmark kidney: a curable cause of hypertension in young patients.

We are reporting a case of arterial hypertension in a young woman who had an atrophic kidney with a cortical groove and histological features of the Ask-Upmark kidney. Her hypertension was renin dependent and the patient was cured following nephrectomy. Controversy on the pathogenesis of this clinical entity is briefly reviewed.

Tuberculosis en zona de gran incidencia y con elevado porcentaje de inmigrantes / Tuberculosis in an area high incidence and a large percentage of immigrants

No disponible

Efficacy and safety of clarithromycin versus erythromycin for the treatment of pertussis: a prospective, randomized, single blind trial.

BACKGROUND: Pertussis is still a prevalent public health problem, and antibiotic therapy may decrease disease severity and limit communicability. Erythromycin is the recommended antibiotic for treatment and prophylaxis of pertussis; however, side effects of erythromycin limit its usefulness in some patients. Clarithromycin, a newer macrolide, has good in vitro activity against Bordetella pertussis and a better side effect profile. GOALS OF THE STUDY: To compare the microbiologic and clinical efficacy and the clinical safety of a 7-day course of clarithromycin vs. a 14-day course of erythromycin in children with pertussis. DESIGN: Prospective, randomized, single blind (investigator), parallel group trial. METHODS: Children from 1 month to 16 years of age presenting with a clinically defined pertussis syndrome were eligible for the study. After obtaining informed written consent, we randomized patients to receive either clarithromycin (7.5 mg/kg/dose twice a day for 7 days) or erythromycin (13.3 mg/kg/dose three times a day for 14 days). Nasopharyngeal cultures for B. pertussis were performed at enrollment and after end of treatment. Clinical assessments were performed at enrollment, at end of treatment and at a 1-month follow-up visit. Adverse event data were collected throughout the study. RESULTS: The clarithromycin (n = 76) and erythromycin (n = 77) groups were well-matched for age and previous pertussis immunization. Microbiologic eradication and clinical cure rates were 100% (31 of 31) for clarithromycin and 96% (22 of 23) for erythromycin. The clarithromycin group had significantly fewer adverse events [45% (34 of 76) for clarithromycin vs. 62% (48 of 77) for erythromycin; P = 0.035], and compliance with the medication regimen was significantly higher in these patients. CONCLUSIONS: A 7-day regimen of clarithromycin and a 14-day course of erythromycin were equally effective for treatment of pertussis. Clarithromycin was better tolerated than conventional erythromycin therapy.

Werner syndrome: genetic and molecular basis of a premature aging disorder.

Werner syndrome (WS) is a rare autosomal recessive disorder characterized by genomic instability and by the premature onset of a number of age-related diseases, including cancers. The gene responsible for WS encodes a protein that has an exonuclease domain and a domain similar to DNA helicases of the RecQ-like subfamily. Accumulating evidence indicates that the WS gene product is involved in resolving aberrant DNA structures that may arise during the process of DNA replication and transcription. Such processes generate regions of single-stranded DNA that may inadvertently provide a substrate for the initiation of recombination. Various mechanisms have evolved to ensure that recombination does not occur promiscuously during these events, and results are consistent with a model in which the WS protein is part of one such mechanism.

Blood pressure-independent effect of angiotensin AT1 receptor blockade on renal endothelin-1 production in hypertensive uremic rats.

OBJECTIVE: We recently reported that treatment of uremic rats with reduced renal mass with the angiotensin II (Ang II) subtype 1 receptor (AT1) antagonist losartan reduces endothelin-1 (ET-1) levels in blood vessels and in glomeruli. Although this suggests an important role for Ang II in the modulation of ET-1 production, the concomitant decrease in blood pressure may also be involved. The present study was designed to investigate whether the modulation of ET-1 production in uremic rats is related to tissue-specific effects of AT1 receptor blockade or to the antihypertensive effect of losartan. DESIGN: One week after renal mass reduction, uremic rats were treated with the conventional triple therapy (TRx) [reserpine (5 mg/l), hydralazine (80 mg/l) and hydrochlorothiazide (25 mg/l)] or losartan (20 mg/kg per day) for 6 weeks. Immunoreactive-ET-1 (ir-ET-1) levels in plasma and urine, as well as in vascular and renal tissues were measured by a specific radioimmunoassay after sample extraction and purification. RESULTS: Before treatment, systolic blood pressure was significantly higher in uremic animals compared to sham-operated controls (165+/-4 versus 123+/-2 mmHg, respectively; P < 0.01). Treatment with the TRx or with losartan normalized systolic blood pressure in uremic rats, whereas it was further increased in untreated uremic animals. At week 6, serum creatinine, proteinuria and urinary ET-1 and transforming growth factor-beta1 (TGF-beta1) excretion, as well as vascular and glomerular ET-1 content were increased in uremic rats compared to the controls (P < 0.01). Treatment of uremic rats with the TRx or with losartan reduced ET-1 content in the thoracic aorta and the mesenteric arterial bed (P < 0.01). However, losartan, but not the TRx, significantly attenuated the rise of serum creatinine, proteinuria and urinary ET-1 and TGF-beta1 excretion, as well as ET-1 content in glomeruli of uremic rats. Compared with the controls, renal preproET-1 mRNA expression was also significantly higher in uremic rats. Treatment of uremic rats with losartan prevented renal preproET-1 mRNA overexpression, indicating that changes in glomerular ET-1 content and urinary ET-1 excretion were related to modulation of renal ET-1 production. CONCLUSIONS: These findings indicate that the effect of losartan on ET-1 production in peripheral blood vessels may be mediated, in part, by the reduction of blood pressure. In contrast, the reduction of renal ET-1 production is mediated by tissue-specific effects of AT1 receptor blockade, and may contribute to the renal protective effects of losartan.

Captopril suppression versus salt loading in confirming primary aldosteronism.

This prospective study was designed to compare the captopril suppression test with the salt-loading approach to confirm the diagnosis of primary aldosteronism. A total of 49 patients were referred with a presumed diagnosis of primary aldosteronism. The captopril test was performed in the morning with patients in the seated position after overnight fasting. Blood samples for plasma aldosterone were obtained before captopril administration (25 mg PO) and again 2 hours later. Patients were then subjected to a high salt diet (300 mmol sodium per day for 3 days). On the third day, urinary sodium (24 hours) was measured, and plasma aldosterone levels were measured at 8:00 AM (recumbent) and at noon (standing). Of the 49 patients, 44 had nonsuppressible aldosterone concentrations with all the clinical characteristics of primary aldosteronism: 22 patients had surgically confirmed unique adenoma, and 22 patients had presumed bilateral hyperplasia. There was a significant correlation between plasma aldosterone values of salt-loaded patients (mean of 8:00 AM and noon results) and the values 2 hours after captopril administration (r=0.8, P<0.01). Plasma aldosterone cumulative distribution curves in primary aldosteronism patients (adenoma and hyperplasia) were not significantly different between the 2 suppression tests. Our results showed that the captopril suppression test is as effective as sodium loading in confirming the diagnosis of primary aldosteronism.