Anemia of the Belgrade rat: evidence for defective membrane transport of iron

The mechanisms underlying the impaired utilization of transferrin-bound iron by erythroid cells in the anemia of the Belgrade laboratory rat were investigated using reticulocytes from homozygous anemic animals and transferrin labeled with 59Fe and 125I. The results were compared with those obtained using reticulocytes from phenylhydrazine-treated rats and iron-deficient rats. Each step in the iron uptake mechanism was investigated, ie, transferrin-receptor interaction, transferrin endocytosis, iron release from transferrin, and transferrin exocytosis. Although there were quantitative differences, no fundamental difference was found in any of the abovementioned aspects of cellular function when the reticulocytes from Belgrade rats were compared with those from iron-deficient animals. The basic defect in the Belgrade reticulocytes must therefore reside in subsequent steps in iron uptake, after it is released from transferrin within endocytotic vesicles, ie, in the mechanism by which it is transferred across the lining membrane of the vesicles into the cell cytosol. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of reticulocyte ghosts extracts demonstrated a prominent protein band of mol wt 69,000 that was absent or present only in low concentration extracts from the other two types of reticulocytes. This may be a result of the genetic defect.     

The combined self- and parent-rated SDQ score profile predicts care use and psychiatric diagnoses

European Child & Adolescent Psychiatry - The Strengths and Difficulties Questionnaire (SDQ) is widely used, based on evidence of its value for screening. This evidence primarily regards the...     

Age-related changes in rostral basal forebrain cholinergic and GABAergic projection neurons: relationship with spatial impairment

Both cholinergic and GABAergic projections from the rostral basal forebrain contribute to hippocampal function and mnemonic abilities. While dysfunction of cholinergic neurons has been heavily implicated in age-related memory decline, significantly less is known regarding how age-related changes in codistributed GABAergic projection neurons contribute to a decline in hippocampal-dependent spatial learning. In the current study, confocal stereology was used to quantify cholinergic (choline acetyltransferase [ChAT] immunopositive) neurons, GABAergic projection (glutamic decarboxylase 67 [GAD67] immunopositive) neurons, and total (neuronal nuclei [NeuN] immunopositive) neurons in the rostral basal forebrain of young and aged rats that were first characterized on a spatial learning task. ChAT immunopositive neurons were significantly but modestly reduced in aged rats. Although ChAT immunopositive neuron number was strongly correlated with spatial learning abilities among young rats, the reduction of ChAT immunopositive neurons was not associated with impaired spatial learning in aged rats. In contrast, the number of GAD67 immunopositive neurons was robustly and selectively elevated in aged rats that exhibited impaired spatial learning. Interestingly, the total number of rostral basal forebrain neurons was comparable in young and aged rats, regardless of their cognitive status. These data demonstrate differential effects of age on phenotypically distinct rostral basal forebrain projection neurons, and implicate dysregulated cholinergic and GABAergic septohippocampal circuitry in age-related mnemonic decline.     

Systematic review of enhanced recovery after gastro-oesophageal cancer surgery

Introduction

Fast track methodology or enhanced recovery schemes have gained increasing popularity in perioperative care. While evidence is strong for colorectal surgery, its importance in gastric and oesophageal surgery has yet to be established. This article reviews the evidence of enhanced recovery schemes on outcome for this type of surgery.

Methods

A systematic literature search was conducted up to March 2014. Studies were retrieved and analysed using predetermined criteria.

Results

From 34 articles reviewed, 18 eligible studies were identified: 7 on gastric and 11 on oesophageal resection. Three randomised controlled trials, five case-controlled studies and ten case series were identified. The reported protocols included changes to each stage of the patient journey from pre to postoperative care. The specific focus following oesophageal resections was on early mobilisation, a reduction in intensive care unit stay, early drain removal and early (or no) contrast swallow studies. Following gastric resections, the emphasis was on reducing epidural anaesthesia along with re-establishing oral intake in the first three postoperative days and early removal of nasogastric tubes.In the papers reviewed, mortality rates following fast track surgery were 0.8% (9/1,075) for oesophageal resection and 0% (0/329) for gastric resection. The reported morbidity rate was 16.5% (54/329) following gastric resection and 38.6% (396/1,075) following oesophageal resection. Length of stay was reduced in both groups compared with conventional recovery groups in comparative studies.

Conclusions

The evidence for enhanced recovery schemes following gastric and oesophageal resection is weak, with only three (low volume) published randomised controlled trials. However, the enhanced recovery approach appears safe and may be associated with a reduction in length of stay.     

Autoantibodies against the platelet glycoprotein IIb/IIIa complex in patients with chronic ITP

Chronic idiopathic thrombocytopenic purpura (ITP) is caused by an antibody reactive with platelet-associated antigens. The present studies provide direct evidence that some patients with chronic ITP have autoantibodies against the platelet glycoprotein (GP) IIb/IIIa complex. Microtiter wells, coated with a monoclonal antibody (2G12) specific for GPIIb/GPIIIa were reacted with GPIIb/GPIIIa contained in a platelet extract. Control wells containing the same antibody were reacted with a cell extract containing no GPIIb/GPIIIa. After washing, the wells were reacted with patient or control plasma, and IgG binding was detected using 125I-Fab2-anti-human IgG. Assay values were expressed as binding ratios (cpm GPIIb/GPIIIa wells/cpm control wells). Plasma from 5 of 56 patients with chronic ITP had ratios (1.36-3.14) greater than 3 standard deviations above the mean (+/- SD) of control plasmas--0.93 +/- 0.12. Elevated values were also noted in two patients with anti-P1A1 antibody (ratios greater than 30) and in one patient with Hodgkin's disease and an ITP-like syndrome (ratio 1.53). Normal values were noted in 34 patients with a variety of immune and nonimmune diseases. Plasma from two of the positive ITP patients was reacted with 125I-surface-labeled platelets and, after solubilization, the IgG and bound antigen were precipitated with Staph-A. Autoradiographs from SDS- PAGE electrophoresis of the Staph-A-bound proteins shows two radioactive bands consistent in size with GPIIb and GPIIIa.     

Death-associated protein kinase 1 promotes growth of p53-mutant cancers

Estrogen receptor–negative (ER-negative) breast cancers are extremely aggressive and associated with poor prognosis. In particular, effective treatment strategies are limited for patients diagnosed with triple receptor–negative breast cancer (TNBC), which also carries the worst prognosis of all forms of breast cancer; therefore, extensive studies have focused on the identification of molecularly targeted therapies for this tumor subtype. Here, we sought to identify molecular targets that are capable of suppressing tumorigenesis in TNBCs. Specifically, we found that death-associated protein kinase 1 (DAPK1) is essential for growth of p53-mutant cancers, which account for over 80% of TNBCs. Depletion or inhibition of DAPK1 suppressed growth of p53-mutant but not p53-WT breast cancer cells. Moreover, DAPK1 inhibition limited growth of other p53-mutant cancers, including pancreatic and ovarian cancers. DAPK1 mediated the disruption of the TSC1/TSC2 complex, resulting in activation of the mTOR pathway. Our studies demonstrated that high DAPK1 expression causes increased cancer cell growth and enhanced signaling through the mTOR/S6K pathway; evaluation of multiple breast cancer patient data sets revealed that high DAPK1 expression associates with worse outcomes in individuals with p53-mutant cancers. Together, our data support targeting DAPK1 as a potential therapeutic strategy for p53-mutant cancers.     

The Effects of Aldosterone Synthase Inhibition on Aldosterone and Cortisol in Patients With Hypertension: A Phase II, Randomized, Double-Blind, Placebo-Controlled, Multicenter Study

J Clin Hypertens (Greenwich). 2012; 14:580–587. © 2012 Wiley Periodicals, Inc. Blockade of the renin‐angiotensin‐aldosterone system (RAAS) is an established method to lower blood pressure in patients with hypertension. Aldosterone, the end product of the RAAS cascade, acts by increasing salt reabsorption in the kidney and catecholamine release from the adrenal medulla. Currently available aldosterone inhibitors have the disadvantage of increasing circulating aldosterone and thus may lead to aldosterone breakthrough. Aldosterone synthase inhibition (ASI) is a novel approach to suppressing the RAAS. Due to homology between the enzymes responsible for aldosterone synthesis (CYP11B2) and cortisol synthesis (CYP11B1), the blockade of aldosterone synthesis may also suppress cortisol release. The authors evaluated the effect of the novel ASI LCI699 on the cortisol response to adrenocorticotropic hormone (ACTH) stimulation in patients with hypertension in order to find the maximally tolerated dose (MTD) in this patient population. Among the 63 patients evaluated, there was a dose‐ and time‐dependent effect of LCI699 on both aldosterone and ACTH‐stimulated cortisol. Based on exposure‐response analysis, the MTD was estimated to be 1.30 mg once daily with a 90% prediction interval of 0.88 mg once daily to 1.81 mg once daily. No patients required intervention for adrenal insufficiency. LCI699 was well tolerated with no serious adverse events.