Long-term benefits of full-day kindergarten: a longitudinal population-based study

In the first longitudinal, population-based study of full-day kindergarten (FDK) outcomes beyond primary school in Canada, we used linked administrative data to follow 15 kindergarten cohorts (n ranging from 112 to 736) up to grade 9. Provincial assessments conducted in grades 3, 7, and 8 and course marks and credits earned in grade 9 were compared between FDK and half-day kindergarten (HDK) students in both targeted and universal FDK programmes. Propensity score matched cohort and stepped-wedge designs allowed for stronger causal inferences than previous research on FDK. We found limited long-term benefits of FDK, specific to the type of programme, outcomes examined, and subpopulations. FDK programmes targeted at low-income areas showed long-term improvements in numeracy for lower income girls. Our results suggest that expectations for wide-ranging long-term academic benefits of FDK are unwarranted.

Incorporation of monovalent cations in sulfate green rust

Green rust is a naturally occurring layered mixed-valent ferrous-ferric hydroxide, which can react with a range of redox-active compounds. Sulfate-bearing green rust is generally thought to have interlayers composed of sulfate and water. Here, we provide evidence that the interlayers also contain monovalent cations, using X-ray photoelectron spectroscopy and synchrotron X-ray scattering. For material synthesized with Na(+), K(+), Rb(+), or Cs(+), interlayer thickness derived from basal plane spacings correlates with the radius of the monovalent cation. In addition, sequential washing of the materials with water showed that Na(+) and K(+) were structurally fixed in the interlayer, whereas Rb(+) and Cs(+) could be removed, resulting in a decrease in the basal layer spacing. The incorporation of cations in the interlayer opens up new possibilities for the use of sulfate green rust for exchange reactions with both anions and cations: e.g., radioactive Cs.

Gastric and endobronchial metastases in a case of lobular breast cancer

Background

Invasive lobular carcinoma (ILC) is the second most common histological type of invasive breast carcinoma, preceded only by infiltrating ductal carcinoma, which has clinical, biological and molecular distinctions. These distinctions imply a different metastatic behavior between the histology of these 2 types of breast cancer.

Case Presentation

We report the case of a 51-year-old woman with breast cancer with ILC histology, diagnosed at an early stage. In the course of her disease, recurrences in the gastric mucosa and endobronchial area occurred. The treatment she received is described herein.

Conclusion

This is a case of ILC with unusual metastases. The absence of E-cadherin is related to the carcinogenesis of ILC and probably to these patterns of metastasis as well.

The utility of repeat enzyme immunoassay testing for the diagnosis of Clostridium difficile infection: a systematic review of the literature

Over the last 20 years, the prevalence of healthcare-associated Clostridium difficile (C. diff) disease has increased. While multiple tests are available for the diagnosis of C. diff infection, enzyme immunoassay (EIA) testing for toxin is the most used. Repeat EIA testing, although of limited utility, is common in medical practice. To assess the utility of repeat EIA testing to diagnose C. diff infections. Systematic literature review. Eligible studies performed >1 EIA test for C. diff toxin and were published in English. Electronic searches of MEDLINE and EMBASE were performed and bibliographies of review articles and conference abstracts were hand searched. Of 805 citations identified, 32 were reviewed in detail and nine were included in the final review. All studies except one were retrospective chart reviews. Seven studies had data on number of participants (32,526), and the overall reporting of test setting and patient characteristics was poor. The prevalence of C. diff infection ranged from 9.1% to 18.5%. The yield of the first EIA test ranged from 8.4% to 16.6%, dropping to 1.5-4.7% with a second test. The utility of repeat testing was evident in outbreak settings, where the yield of repeat testing was 5%. Repeat C. diff testing for hospitalized patients has low clinical utility and may be considered in outbreak settings or when the pre-test probability of disease is high. Future studies should aim to identify patients with a likelihood of disease and determine the utility of repeat testing compared with empiric treatment.

Toroidal surface complexes of bacteriophage ϕ12 are responsible for host-cell attachment

Cryo-electron tomography and subtomogram averaging are utilized to determine that the bacteriophage ϕ12, a member of the Cystoviridae family, contains surface complexes that are toroidal in shape, are composed of six globular domains with six-fold symmetry, and have a discrete density connecting them to the virus membrane-envelope surface. The lack of this kind of spike in a reassortant of ϕ12 demonstrates that the gene for the hexameric spike is located in ϕ12's medium length genome segment, likely to the P3 open reading frames which are the proteins involved in viral-host cell attachment. Based on this and on protein mass estimates derived from the obtained averaged structure, it is suggested that each of the globular domains is most likely composed of a total of four copies of P3a and/or P3c proteins. Our findings may have implications in the study of the evolution of the cystovirus species in regard to their host specificity.

Swallowing-induced atrial tachyarrhythmia triggered by salbutamol: case report and review of the literature

CASE

A 49-year-old patient experienced chest discomfort while swallowing. On electrocardiogram, episodes of atrial tachyarrhythmia were recorded immediately after swallowing; 24-hour Holter monitoring recorded several events. The arrhythmia resolved after therapy with atenolol, but recurred a year later. The patient noticed that before these episodes he had been using an inhalator of salbutamol. After stopping the beta-agonist, and after a week with the atenolol, the arrhythmia disappeared.

DISCUSSION

Swallowing-induced atrial tachyarrhythmia (SIAT) is a rare phenomenon. Fewer than 50 cases of SIAT have been described in the literature. This article summarizes all the cases published, creating a comprehensive review of the current knowledge and approach to SIAT. It discusses demographics, clinical characteristics and types of arrhythmia, postulated mechanisms of SIAT, and different treatment possibilities such as medications, surgery, and radiofrequency catheter ablation (RFCA).

CONCLUSION

Salbutamol is presented here as a possible trigger for SIAT. Although it is difficult to define causality in a case report, it is logical to think that a beta-agonist like salbutamol (known to induce tachycardia) may be the trigger of adrenergic reflexes originating in the esophagus while swallowing and that a beta-blocker such as atenolol (that blocks the adrenergic activity) may relieve it.

Review. Colon cancer vaccines: an update

Despite advances in research and treatment modalities, colorectal cancer still accounts for around half a million deaths yearly worldwide. Traditional and even newer pharmaceutical therapeutic regimens are limited in terms of tolerance, efficacy and cross-resistance. Additional non-cross resistant therapies with non-overlapping toxicities are needed to improve the outcome for patients with colorectal cancer. Cancer vaccines, designed to activate immune effectors (T-cells and antibodies) to prevent recurrence or treat advanced cancers, have now demonstrated clinical benefit in prostate cancer and lymphoma. Because immune effector infiltration into colon tumours is associated with improved clinical outcome, vaccines intended to activate immune responses against colon cancer have generated significant interest. This review discusses data supportive of the immune responsiveness of colorectal cancer, as well as the current status of colon cancer vaccines under development including those based on whole tumour cells or lysates, peptide or protein antigens, anti-idiotype antibodies, viral vectors, and dendritic cells. We also discuss challenges to colon cancer vaccine development, such as tumour associated mechanisms for immune evasion, and how future strategies may address these challenges.

Review of chromium (VI) apoptosis, cell-cycle-arrest, and carcinogenesis

Hexavalent chromium combines with glutathione in chloride intracellular channel carrier to form tetravalent and pentavalent chromium in plasma and organelle membranes. It also combines with NADH/NADPH to form pentavalent chromium in mitochondria. Tetravalent- and pentavalent- chromium (directly and indirectly) mediated DNA double strand breaks activate DNA damage signaling sensors: DNA-dependent-protein-kinase signals p53-dependent intrinsic mitochondrial apoptosis, and ataxia-telangiectasia-mutated and ataxia-telangiectasia-Rad3-related signal cell-arrest for DNA repair. Tetravalent chromium may be the most potent species since it causes DNA breaks and somatic recombination, but not apoptosis. Upon further failure of apoptosis and senescence/DNA-repair, damaged cells may become immortal with loss-of-heterozygosity and genetic plasticity.