Altered interleukin-2 production in schizophrenia: association between clinical state and autoantibody production.

Mitogen-stimulated interleukin-2 (IL-2) production was measured in 122 patients who met Research Diagnostic Criteria for schizophrenia and 98 normal control subjects. The presence of autoantibodies against seven common antigens was also determined. There was no relationship between the presence of circulating autoantibodies and IL-2 production in control subjects. In patients, however, autoantibody-positive, acutely ill patients had significantly lower IL-2 production as compared with other patients and control subjects. Never-medicated patients showed the same trends for decreased IL-2 production in association with autoantibodies. These data suggest that decreased IL-2 production is associated with acute illness in schizophrenic patients who produce autoantibodies, a trait known to be associated with increased vulnerability to autoimmune disease.     

Black–white racial disparities in household food insecurity from 2005 to 2014, Canada

ObjectivesTo understand the differential vulnerability to household food insecurity of the Black population as compared with white counterparts in Canada.MethodsUsing data for households with Black and white respondents in pooled Canadian Community Health Survey cycles from 2005 to 2014, the 18-question Household Food Security Survey Module was analyzed (N = 491,400). Bivariate and multivariate logistic and multinomial regression models were run using respondent’s race, immigration status, and six well-established predictors of household food insecurity in the general population. Additional multivariable logistic regression models were run, with race interacted with each predictor individually to yield predicted probabilities.ResultsThe weighted prevalence of household food insecurity was 10.0% for white respondents and 28.4% for Black respondents. The odds of Black households being food-insecure as compared with white households fell from 3.56 (95% CI: 3.30–3.85) to 1.88 (95% CI: 1.70–2.08) with adjustment for household socio-demographic characteristics. In contrast with white households, there was relative homogeneity of risk of food insecurity among Black subgroups defined by immigration status, household composition, education, and province of residence. Homeownership was associated with lower probabilities of food insecurity for Black and white households, but the probability among Black owners was similar to that for white renters (14.7% vs. 14.3%). Black households had significantly higher predicted probabilities of food insecurity than their white counterparts across all main sources of household income except child benefits and social assistance.ConclusionBeing racialized as Black appears to be an overriding factor shaping vulnerability to food insecurity for the Black population in Canada. Future research and public policy on food insecurity should seriously consider the role of racism at the systemic and institutional levels.     

Ophthalmoplegia in an adult with chronic inflammatory demyelinating polyradiculoneuropathy

The authors present a 75-year-old patient with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and ophthalmoplegia. The patient had recurrent exacerbations and remissions of her polyneuropathy over the course of one year. Antibodies to ganglioside GM-I were not detected. Ophthalmoplegia in CIDP is uncommon, but is reported to occur in 3-8% of patients. Ophthalmologists should be aware of the association of CIDP and ophthalmoplegia.     

In utero presentation of aggressive systemic mastocytosis in a neonate

Mastocytosis is a clinically heterogenous disease characterized by mast cell hyperplasia in skin, bone marrow and/or visceral organs. Cutaneous mastocytosis is more frequently observed in children, whereas indolent systemic mastocytosis is more commonly observed in adults. Aggressive systemic presentation, particularly of the neonate, is exceptionally rare. We present a rare case of congenital aggressive systemic mastocytosis. The patient was a 37‐week‐old male, born by caesarean section owing to hepatosplenomegaly and ascites diagnosed in utero, who exhibited extensive cutaneous and systemic manifestations of mastocytosis at birth. Mutation analysis of c‐KIT identified D816V mutation in exon 17. Although initial bilateral bone marrow aspirates demonstrated no mast‐cell infiltrates or haematological neoplasm, subsequent bone‐marrow biopsies postmortem exhibited multifocal mast‐cell aggregates. Clinical course was complicated by bacteraemia and cardiorespiratory failure, leading to death at 10 weeks.     

The antihypertensive chromogranin a peptide catestatin acts as a novel endocrine/paracrine modulator of cardiac inotropism and lusitropism

Circulating levels of catestatin (Cts; human chromogranin A352-372) decrease in the plasma of patients with essential hypertension. Genetic ablation of the chromogranin A (Chga) gene in mice increases blood pressure and pretreatment of Chga-null mice with Cts prevents blood pressure elevation, indicating a direct role of Cts in preventing hypertension. This notable vasoreactivity prompted us to test the direct cardiovascular effects and mechanisms of action of wild-type (WT) Cts and naturally occurring human variants (G364S-Cts and P370L-Cts) on myocardial and coronary functions. The direct cardiovascular actions of WT-Cts and human variants were determined using the Langendorff-perfused rat heart. WT-Cts dose-dependently increased heart rate and coronary pressure and decreased left ventricular pressure, rate pressure product and both positive and negative LVdP/dt. WT-Cts not only inhibited phospholamban phosphorylation, but also the inotropic and lusitropic effects of WT-Cts were abolished by chemical inhibition of beta2-adrenergic receptors, Gi/o protein, nitric oxide or cGMP, indicating involvement of beta2-adrenergic receptors-Gi/o protein-nitric oxide-cGMP signaling mechanisms. In contrast, G364S-Cts did not affect basal cardiac performance but abolished isoproterenol-induced positive inotropism and lusitropism. P370L-Cts decreased rate pressure product and inhibited only isoproterenol-induced positive inotropism and lusitropism by 70%. Cts also inhibited endothelin-1-induced positive inotropism and coronary constriction. Taken together, the cardioinhibitory influence exerted on basal mechanical performance and the counterregulatory action against beta-adrenergic and endothelin-1 stimulations point to Cts as a novel cardiac modulator, able to protect the heart against excessive sympathochromaffin overactivation, e.g. hypertensive cardiomyopathy.     

A Novel KCNJ13 Nonsense Mutation and Loss of Kir7.1 Channel Function Causes Leber Congenital Amaurosis (LCA16)

Mutations in the KCNJ13 gene that encodes the inwardly rectifying potassium channel Kir7.1 cause snowflake vitreoretinal degeneration (SVD) and leber congenital amaurosis (LCA). Kir7.1 controls the microenvironment between the photoreceptors and the retinal pigment epithelium (RPE) and also contributes to the function of other organs such as uterus and brain. Heterologous expressions of the mutant channel have suggested a dominant‐negative loss of Kir7.1 function in SVD, but parallel studies in LCA16 have been lacking. Herein, we report the identification of a novel nonsense mutation in the second exon of the KCNJ13 gene that leads to a premature stop codon in association with LCA16. We have determined that the mutation results in a severe truncation of the Kir7.1 C‐terminus, alters protein localization, and disrupts potassium currents. Coexpression of the mutant and wild‐type channel has no negative influence on the wild‐type channel function, consistent with the normal clinical phenotype of carrier individuals. By suppressing Kir7.1 function in mice, we were able to reproduce the severe LCA electroretinogram phenotype. Thus, we have extended the observation that Kir7.1 mutations are associated with vision disorders to include novel insights into the molecular mechanism of disease pathobiology in LCA16.     

End-Stage Renal Disease and Mortality Outcomes Across Different Glomerulonephropathies in a Large Diverse US Population

Objective

To compare renal function decline, incident end-stage renal disease (ESRD), and mortality among patients with 5 common glomerular diseases in a large diverse population.

Ventricular fibrillation in a left ventricular assist device patient: Can the echocardiogram be misleading?

Sustained ventricular tachycardia and ventricular fibrillation (VF) are life-threatening arrhythmias which remain highly prevalent in patients with advanced heart failure. These ventricular arrhythmias may impair the support provided by continuous-flow left ventricular assist devices (CF-LVADs) and lead to frequent hospitalizations, antiarrhythmic medication use, external defibrillations, and need for heart transplantation. We report a case in which a patient with a CF-LVAD and an implantable cardioverter defibrillator at end of life presented with asymptomatic low-flow alarms and was found to have VF of unknown duration. Unique in our case was the presence of apparent organized contractility and rhythmic opening of the mitral valve on echocardiogram despite VF on electrocardiogram.