Elimination of virus-like particles reduces protein aggregation and extends replicative lifespan in Saccharomyces cerevisiae

A major consequence of aging and stress, in yeast to humans, is an increased accumulation of protein aggregates at distinct sites within the cells. Using genetic screens, immunoelectron microscopy, and three-dimensional modeling in our efforts to elucidate the importance of aggregate annexation, we found that most aggregates in yeast accumulate near the surface of mitochondria. Further, we show that virus-like particles (VLPs), which are part of the retrotransposition cycle of Ty elements, are markedly enriched in these sites of protein aggregation. RNA interference-mediated silencing of Ty expression perturbed aggregate sequestration to mitochondria, reduced overall protein aggregation, mitigated toxicity of a Huntington's disease model, and expanded the replicative lifespan of yeast in a partially Hsp104-dependent manner. The results are in line with recent data demonstrating that VLPs might act as aging factors in mammals, including humans, and extend these findings by linking VLPs to a toxic accumulation of protein aggregates and raising the possibility that they might negatively influence neurological disease progression.

Working Memory in Children With Learning Disabilities in Reading Versus Spelling: Searching for Overlapping and Specific Cognitive Factors

In transparent orthographies like German, isolated learning disabilities in either reading or spelling are common and occur as often as a combined reading and spelling disability. However, most issues surrounding the cognitive causes of these isolated or combined literacy difficulties are yet unresolved. Recently, working memory dysfunctions have been demonstrated to be promising in explaining the emergence of literacy difficulties. Thus, we applied a 2 (reading disability: yes vs. no) × 2 (spelling disability: yes vs. no) factorial design to examine distinct and overlapping working memory profiles associated with learning disabilities in reading versus spelling. Working memory was assessed in 204 third graders, and multivariate analyses of variance were conducted for each working memory component. Children with spelling disability suffered from more pronounced phonological loop impairments than those with reading disability. In contrast, domain-general central-executive dysfunctions were solely associated with reading disability, but not with spelling disability. Concerning the visuospatial sketchpad, no impairments were found. In sum, children with reading disability and those with spelling disability seem to be characterized by different working memory profiles. Thus, it is important to take both reading and spelling into account when investigating cognitive factors of literacy difficulties in transparent orthographies.

[The comorbidity of learning difficulties and ADHD symptoms in primary-school-age children]

Children having difficulties in acquiring early literacy and mathematical skills often show an increased rate of inattention, hyperactivity, and impulsivity. This study provides data on the comorbidity rates of specific learning difficulties and ADHD symptoms. We analyzed the data of 273 children with learning difficulties despite an at least average IQ, 57 children with low IQ, and 270 children without learning difficulties and average IQ (comparison group). We assessed children’s IQ and school achievement using standardized achievement tests. ADHD symptoms were assessed via parents’ ratings. Our results showed that only 5 % of both the control group and the group with solely mathematical difficulties fulfilled the criteria of an ADHD subtype according to the DSM-IV based on parents’ ratings. In contrast, this was the case in even 20 % of the children with difficulties in reading/writing and of those with low IQ. Compared to girls, boys in the control group had a 150% higher risk for matching the criteria of one of the ADHD subtypes in parents’ ratings, whereas boys with learning difficulties and those with low IQ had an even 200% to 600% higher risk for it. The relationship between learning difficulties and ADHD symptoms can be found predominantly in the inattentive type. Possible reasons for the results are discussed.

Working Memory Functioning in Children With Poor Mathematical Skills

Previous research on working memory (WM) in children with poor mathematical skills has yielded heterogeneous results, possibly due to inconsistent consideration of the IQ–achievement discrepancy and additional reading and spelling difficulties. To examine the impact of both, the WM of 68 average-achieving and 68 low-achieving third-graders in mathematics was assessed. Preliminary analyses showed that poor mathematical skills were associated with poor WM. Afterwards, children with isolated mathematical difficulties were separated from those with additional reading and spelling difficulties. Half of each group fulfilled the IQ–achievement discrepancy, resulting in a 2 (additional reading and spelling difficulties: yes/no) by 2 (IQ–achievement discrepancy: yes/no) factorial design. Analyses revealed that not fulfilling the IQ–achievement discrepancy was associated with poor visual WM, whereas additional reading and spelling difficulties were associated with poor central executive functioning in children fulfilling the IQ–achievement discrepancy. Therefore, WM in children with poor mathematical skills differs according to the IQ–achievement discrepancy and additional reading and/or spelling difficulties.

Prävalenz von Lernschwächen und Lernstörungen: Zur Bedeutung der Diagnosekriterien

In dieser Studie wurden die Prävalenzraten von Lernschwächen und Lernstörungen und hierbei auftretende Geschlechtsunterschiede in der Mitte der Grundschulzeit anhand einer großen deutschen Stichprobe (N = 2195) untersucht. Bei Lernschwächen und -störungen treten isolierte oder mehrfache Minderleistungen in den drei basalen schulischen Grundkompetenzen Lesen, Rechtschreiben und Rechnen trotz einer unbeeinträchtigten Intelligenz auf. Die Lernstörung wird hier als eine Untergruppe der Lernschwäche verstanden und liegt nach ICD-10 (WHO, 2005) dann vor, wenn neben der Leistungsabweichung von der Norm zusätzlich eine deutliche Diskrepanz zwischen der Minderleistung und der Intelligenz eines Kindes besteht (sogenanntes doppeltes Diskrepanzkriterium). Die Ergebnisse zeigen, dass insgesamt bei 23.3 % der Kinder eine Lernschwäche in einem oder mehreren Leistungsbereichen vorliegt. In etwa die Hälfte dieser Kinder verfehlt das zusätzliche Kriterium für eine Lernstörungsdiagnose. Betrachtet man die einzelnen Prävalenzraten für isolierte und multiple Lernschwierigkeiten im Lesen, Rechtschreiben und/oder Rechnen, liegen diese bei den Lernschwächen zwischen 4 und 6 % und bei den Lernstörungen zwischen 2 und 4 %. Deutlich mehr Jungen sind von Lese-Rechtschreib- und deutlich mehr Mädchen von Rechenschwierigkeiten betroffen. In bisher vorgelegten Prävalenzstudien wurden nicht alle basalen Schulleistungen berücksichtigt, sondern nur die jeweils diagnosespezifisch fokussierten Minderleistungen. Dadurch sind das Erkennen mehrfach lernbeeinträchtigter Kinder und eine eindeutige Diagnose nach ICD-10 nicht möglich. In der vorliegenden Studie zeigte sich eine Verdoppelung der Prävalenzraten durch das alleinige Berücksichtigen der diagnosespezifisch relevanten Leistungen. Die Befunde werden vor dem Hintergrund der praktischen Relevanz einer ICD-Diagnose und der Bedeutung einer umfassenden Schulleistungsdiagnostik diskutiert.

Zeigen Kinder mit schulischen Minderleistungen sozio-emotionale Auffälligkeiten?

Zusammenfassung. Die vorliegende Studie geht der Frage nach, ob Kinder mit Minderleistungen im Lesen, Rechtschreiben und/oder Rechnen von sozio-emotionalen Auffälligkeiten betroffen sind. Dabei wird unterschieden, ob bei diesen Kindern eine Lernstörung (diagnostiziert nach ICD 10, F81, Umschriebene Entwicklungsstörung schulischer Fertigkeiten) oder eine Lernschwäche vorliegt. Die Lernschwäche unterscheidet sich von der Lernstörung nur darin, dass das für umschriebene Entwicklungsstörungen schulischer Fertigkeiten erforderliche Diskrepanzkriterium zwischen Schulleistung und Intelligenz nicht erfüllt wird. Die Daten von 317 untersuchten Grundschulkindern mit schulischen Minderleistungen zeigen, dass bei Kindern mit einer diagnostizierten Lernstörung als auch mit Lernschwächen Auffälligkeiten im sozio-emotionalen Bereich vorliegen. Dabei ist es unerheblich, ob die Lernschwierigkeiten in der Schriftsprache oder im Rechnen bestehen. Bedeutsam stärker sind jedoch Kinder betroffen, die in der Schriftsprache als auch im Rechnen kombinierte Lernschwierigkeiten haben. Bei den kombinierten Lernschwierigkeiten zeigt sich zudem, dass Lernstörungen im Vergleich zu Lernschwächen verstärkt mit behavioralen und sozialen Problemen sowie Aufmerksamkeitsdefiziten einhergehen.

Results of an etiological therapy applied to patients with different localizations of herpes infection detected by immunofluorescence reaction

An indirect immunofluorescence reaction was used for cytovirological diagnosis in 110 patients with different herpes-like clinical manifestations. The presence of herpes antigens type 1 and 2 was made evident in the exfoliated cells from 77% of the cases with recurrent herpes, in 68% of those with cutaneous and/or oral herpes, in 64% of the cases with keratoconjunctivitis and in 37.5% of the women with different genital diseases. Administration of specific antiherpes immunoglobulins and of the chemotherapeutic drug Flumidin to cases with positive immunofluorescence reactions led to improvement of the symptoms and even to clinical recovery.

Extrarespiratory localizations of parainfluenza viruses

Two hemagglutinating and hemadsorbant agents-serologically identified as parainfluenza viruses type 3-were isolated from the cerebrospinal fluid of a 10-month-old infant with meningoencephalitis and from the urethral secretion of a male patient with nonbacterial urethritis. Parainfluenza virus antigens types 1, 2, and 3 were detected by indirect immunofluorescence reactions in cells exfoliated in the vagina of women with genital neoplasia or common gynecopathies.

Investigations on the presence of viral and chlamydial antigens in cells exfoliated in the vagina of women with common and malignant gynecopathies

A high proportion of parainfluenza, herpes, adenovirus and chlamydial antigens (10.7-36%) was detected by indirect immunofluorescence in cells exfoliated in the vagina of women with genital neoplasia and with uterine cervix ectopia and dysplasia. Much lower proportions of the same antigens were found in patients with common gynecopathies or recurrent genital herpes and in pregnant women. The possible relationships between chronic virus infections and genital neoplasia in women are discussed.