Usefulness of the N-Terminal Fraction of Brain Natriuretic Peptide for Deciding When to Refer Patients With Sleep Apnea-Hypopnea Syndrome to the Cardiologist

Introduction and objectiveWhen sleep apnea-hypopnea syndrome (SAHS) and cardiovascular disease occur concurrently, prognosis is affected. Echocardiography can detect structural cardiac abnormalities but using this technique in all patients would place a heavy burden on resources. The objective of this study was to investigate whether the N-terminal fraction of brain natriuretic peptide (NT-proBNP) can be used as a marker for silent heart disease.Patients and methodsNT-proBNP concentration was measured in the 114 consecutive patients with SAHS who underwent echocardiography before starting treatment. Left and right ventricular systolic and diastolic function, as well as structural abnormalities, were studied. Correlations between NT-proBNP concentration and the abnormalities detected were investigated. A receiver operating characteristics (ROC) curve was plotted for NT-proBNP concentration and cardiac abnormalities.ResultsData for 98 patients were finally analyzed. NT-proBNP concentration was significantly correlated with ventricular septal thickness (r=0.63), posterior wall thickness (r=0.45), and left ventricular enddiastolic diameter (r=0.51) (P<.0001 for all correlations). The area under the ROC curve was significant (0.870; 95% confidence interval, 0.801-0.939; P<.0001). Assuming that specificity would be more useful for clinical practice, we calculated that NT-proBNP concentrations below 100 and 200 pg/mL could rule out structural abnormalities with a reliability of 90% and 100%, respectively.ConclusionsNT-proBNP concentration was strongly correlated with echocardiographic abnormalities and so could be a useful tool for identifying patients who should be referred to the cardiologist.     

Lymph node infarction – a rare complication associated with disseminated intra vascular coagulation in a case of dengue fever

Background  

Lymph node infarction is known to occur in association with many non-neoplastic and neoplastic conditions however its occurrence in association with DIC is not reported hitherto in the literature.     

Antigen-presenting cell function during Plasmodium yoelii infection

Antigen-presenting cells (APC) play a key role in orchestrating immune responses. T-cell proliferative responses are inhibited during the erythrocyte stages of malaria infection, and a number of studies have suggested that APC are responsible for this phenomenon. In the present studies we examine individual components of the T-cell-activating function of APC: expression of costimulatory and major histocompatibility complex (MHC) class II proteins, the ability to process and present antigen to T cells, and the ability to support cytokine production. We find that during the acute phases of Plasmodium yoelii erythrocyte stage infection, APC upregulate the expression of class II MHC and CD80, maintain expression of CD86, process and present antigen, and support gamma interferon production. However the CD11b(+) subpopulation produces a soluble factor or factors that specifically inhibit interleukin-2 (IL-2) production by responding CD4 T cells. This factor is distinct from prostaglandin E(2), NO, or transforming growth factor beta. The data suggest that IL-2 suppression observed during malaria infection is not due to functional defects of APC but is triggered by production of a factor(s) that actively suppresses production of IL-2 by T cells.     

Microbiology and risk factors for community-acquired pneumonia

The outcome of community-acquired pneumonia (CAP) depends on the interaction between the infectious agent and the host response. Nowadays the etiology of CAP can be established in ~60% of the cases, and Streptococcus pneumoniae remains the main etiological agent in outpatients, those hospitalized, or those requiring intensive care unit (ICU) admission. Recently, the development of nucleic acid amplification techniques has emphasized the role of viruses as important etiological agents in CAP. However, some demographic factors and comorbidities will determine a higher risk of pneumonia. Thus elderly patients or those with toxic habits (smoking, alcohol abuse), and the presence of various comorbidities (respiratory, metabolic, or renal) favor the development of pneumonia by altering the inflammatory response to infection.Some medications like inhaled corticosteroids could play a role in CAP development in chronic obstructive pulmonary disease (COPD) patients. Fortunately some of these risk factors are preventable and modifiable, for example, through smoking cessation and pneumococcal and influenza vaccinations, which are the biggest successes.     

Primary visual cortex shows laminar‐specific and balanced circuit organization of excitatory and inhibitory synaptic connectivity

Key points

• Using functional mapping assays, we conducted a quantitative assessment of both excitatory and inhibitory synaptic laminar connections to excitatory neurons in layers 2/3–6 of the mouse visual cortex (V1).
• Laminar‐specific synaptic wiring diagrams of excitatory neurons were constructed on the basis of circuit mapping.
• The present study reveals that that excitatory and inhibitory synaptic connectivity is spatially balanced across excitatory neuronal networks in V1.

Abstract

In the mammalian neocortex, excitatory neurons provide excitation in both columnar and laminar dimensions, which is modulated further by inhibitory neurons. However, our understanding of intracortical excitatory and inhibitory synaptic inputs in relation to principal excitatory neurons remains incomplete, and it is unclear how local excitatory and inhibitory synaptic connections to excitatory neurons are spatially organized on a layer‐by‐layer basis. In the present study, we combined whole cell recordings with laser scanning photostimulation via glutamate uncaging to map excitatory and inhibitory synaptic inputs to single excitatory neurons throughout cortical layers 2/3–6 in the mouse primary visual cortex (V1). We find that synaptic input sources of excitatory neurons span the radial columns of laminar microcircuits, and excitatory neurons in different V1 laminae exhibit distinct patterns of layer‐specific organization of excitatory inputs. Remarkably, the spatial extent of inhibitory inputs of excitatory neurons for a given layer closely mirrors that of their excitatory input sources, indicating that excitatory and inhibitory synaptic connectivity is spatially balanced across excitatory neuronal networks. Strong interlaminar inhibitory inputs are found, particularly for excitatory neurons in layers 2/3 and 5. This differs from earlier studies reporting that inhibitory cortical connections to excitatory neurons are generally localized within the same cortical layer. On the basis of the functional mapping assays, we conducted a quantitative assessment of both excitatory and inhibitory synaptic laminar connections to excitatory cells at single cell resolution, establishing precise layer‐by‐layer synaptic wiring diagrams of excitatory neurons in the visual cortex.

Abbreviations

aCSF

artificial cerebrospinal fluid

DAPI

4′‐6‐diamidino‐2‐phenylindole

LSPS

laser scanning photostimulation

V1

primary visual cortex

     

Eleven novel mutations in the factor VIII gene from Brazilian hemophilia A patients

The molecular characterization of the mutations in hemophilia A patients is hampered by the large size of the factor VIII gene and the great heterogeneity of mutations. In this study, we have performed a protocol involving multiplex polymerase chain reaction in which 19 exons were amplified in four different combinations followed by nonradioactive single-strand conformational polymorphism (SSCP) to screen for mutations. Southern blotting was used to detect inversion of the factor VIII gene resulting from recombination between copies of the gene A (F8A) located in intron 22 of the factor VIII gene and two copies close telomeric region of X chromosome. Forty-two hemophilia A patients (21 with severe and 21 with mild-to-moderate disease) were studied. The inversion of factor VIII occurred in 13 of 21 patients affected by severe hemophilia A. One patient showed a large extra band in addition to the three bands observed after Southern blotting with the F8A probe. An abnormal electrophoretic pattern of SSCP was detected in 85% and 50% of the patients affected by mild-to-moderate and severe disease, respectively. Sixteen different mutations were identified. Eleven mutations were novel and comprised 9 point mutations and 2 small deletions. This study shows that the methodology used is safe and rapid and has potential for detecting almost all of the genetic defects of the studied hemophilia A patients.     

Acute respiratory distress syndrome caused by pulmonary nocardiosis in a patient with systemic lupus erythematosus

Nocardia is a gram-positive bacillus that infects mainly immunodepressed patients. Its association with lupus erythematosus has been described only occasionally and we have found no reports in the literature of an association between lupus and acute respiratory distress syndrome due to pulmonary nocardiosis. We present such a case and discuss the mechanisms that make this lung infection so virulent as well as its epidemiological and microbiological characteristics, clinical presentation, diagnosis, and treatment.