Selected aspects of the human gut microbiota

The gut microbiota represents a highly complex assembly of microbes, which interact with each other and with their host. These interactions have various implications in terms of health and disease, and this multi-author review issue will address a number of selected aspects pertaining to gut microbiota research.     

Immunity to coccidiosis: Gut permeability changes in response to sporozoite invasion

Zusammenfassung Mit einer neuen Methode wird gezeigt, dass die Invasion des Darmepithels von immunen Hühnern durch Sporozoiten verschiedenerEimeria-Arten zu einer vermehrten Durchlässigkeit der Gefässe führt.     

Molecular dialogue between the human gut microbiota and the host: a Lactobacillus and Bifidobacterium perspective

The human gut represents a highly complex ecosystem, which is densely colonized by a myriad of microorganisms that influence the physiology, immune function and health status of the host. Among the many members of the human gut microbiota, there are microorganisms that have co-evolved with their host and that are believed to exert health-promoting or probiotic effects. Probiotic bacteria isolated from the gut and other environments are commercially exploited, and although there is a growing list of health benefits provided by the consumption of such probiotics, their precise mechanisms of action have essentially remained elusive. Genomics approaches have provided exciting new opportunities for the identification of probiotic effector molecules that elicit specific responses to influence the physiology and immune function of their human host. In this review, we describe the current understanding of the intriguing relationships that exist between the human gut and key members of the gut microbiota such as bifidobacteria and lactobacilli, discussed here as prototypical groups of probiotic microorganisms.     

Epigenetic regulation of skin: focus on the Polycomb complex

Chromatin regulators have recently emerged as key players in the control of tissue development and tumorigenesis. One specific chromatin regulator, the Polycomb complex, has been shown to regulate the identity of embryonic stem cells, but its role in controlling fates of multipotent progenitors in developing tissues is still largely unknown. Recent findings have revealed that this complex plays a critical role in control of skin stem cell renewal and differentiation. Moreover, the expression of Polycomb complex components is often aberrant in skin diseases, including skin cancers. This review will detail recent findings on Polycomb control of skin and highlight critical unknown questions.     

Studies on potassium permeability changes in human erythrocytes

Zusammenfassung Die durch Monojodessigsäure und Purinnukleoside erzeugte K-Permeabilitätsänderung der Erythrocyten konnte durch Präinkubation mit Nukleosiden beeinflusst werden. Die Geschwindigkeitsänderung des K-Verlustes ist wahrscheinlich die Folge einer 2,3-Diphosphoglycerinsäure-Stoffwechselveränderung.     

Cytochemical changes of a glycocalyx of human placenta with maturation

Resumen En la superficie libre, en contacto con la sangre materna, del sinciciotrofoblasto de la placenta humana se observó un glicocáliz en el que se han caracterizado carbohidratos complejos, grupos sulfato y ácido siálico. En este glicocáliz se observaron cambios citoquímicos con la edad de la placenta. Con el microscopio electrónico, se describe la apariencia filamentosa del glicocáliz de placenta humana.     

Overview upon miR-21 in lung cancer: focus on NSCLC

Considering the high mortality rate encountered in lung cancer, there is a strong need to explore new biomarkers for early diagnosis and also improved therapeutic targets to overcome this issue. The implementation of microRNAs as important regulators in cancer and other pathologies expanded the possibilities of lung cancer management and not only. MiR-21 represents an intensively studied microRNA in many types of cancer, including non-small cell lung cancer (NSCLC). Its role as an oncogene is underlined in multiple studies reporting the upregulated expression of this sequence in patients diagnosed with this malignancy; moreover, several studies associated this increased expression of miR-21 with a worse outcome within NSCLC patients. The same pattern is supported by the data existent in the Cancer Genome Atlas (TCGA). The carcinogenic advantage generated by miR-21 in NSCLC resides in the target genes involved in multiple pathways such as cell growth and proliferation, angiogenesis, invasion and metastasis, but also chemo- and radioresistance. Therapeutic modulation of miR-21 by use of antisense sequences entrapped in different delivery systems has shown promising results in impairment of NSCLC. Hereby, we review the mechanisms of action of miR-21 in cancer and the associated changes upon tumor cells together a focused perspective on NSCLC signaling, prognosis and therapy.     

Complex changes in the suckling rat's small intestine by the end of the third week of life

Zusammenfassung Die Zusammenhänge zwischen den histologischen Veränderungen und dem Wechsel des Enzymmusters im Darm der Ratte während des Über-ganges von Milch-zur Festnahrung werden beschrieben.     

The locus ceruleus: a possible neural focus for genetic differences in emotionality

The Maudsley Reactive and Non-Reactive strains have been developed as a model for the study of individual variations in stress-reactivity, and many differences in biobehavioral systems have been found between them. This review discusses limitations of the 'emotionality' construct in accounting for differences between the Maudsley strains and offers an alternative, theoretical approach. Amaral and Sinnamon have proposed that the locus ceruleus (LC) plays a stress-attenuating role in mediating behavioral, physiological and neuroendocrine response to prepotent, emergency-provoking stimuli and, building upon this formulation, it is proposed that the LC has been an important focus for gene action in the Maudsley model. It is suggested that the LC of the Non-Reactive strain is more strongly activated by stressful stimuli than the LC of Reactive rats, and is the basis of many of the behavioral and physiological differences between them. Behavioral and biochemical evidence consistent with this proposition is reviewed. Identification of the LC as a target for gene-action in the Maudsley model has an important advantage. It substitutes variations at a specific anatomic location in the brain for a loosely defined construct like emotionality, and the hypothesis is amenable to empirical tests by a variety of experimental approaches.     

The locus ceruleus: a possible neural focus for genetic differences in emotionality

Summary The Maudsley Reactive and Non-Reactive strains have been developed as a model for the study of individual variations in stress-reactivity, and many differences in biobehavioral systems have been found between them. This review discusses limitations of the emotionality construct in accounting for differences between the Maudsley strains and offers an alternative, theoretical approach. Amaral and Sinnamon have proposed that the locus ceruleus (LC) plays a stress-attenuating role in mediating behavioral, physiological and neuroendocrine response to prepotent, emergency-provoking stimuli and, building upon this formulation, it is proposed that the LC has been an important focus for gene action in the Maudsley model. It is suggested that the LC of the Non-Reactive strain is more strongly activated by stressful stimuli than the LC of Reactive rats, and is the basis of many of the behavioral and physiological differences between them. Behavioral and biochemical evidence consistent with this proposition is reviewed. Identification of the LC as a target for gene-action in the Maudsley model has an important advantage. It substitutes variations at a specific anatomic location in the brain for a loosely defined construct like emotionality, and the hypothesis is amenable to empirical tests by a variety of experimental approaches.Supported by MH-39210 from the National Institute of Mental Health to DAB     

Role of gut microbiota in aging-related health decline: insights from invertebrate models

Studies in mammals, including humans, have reported age-related changes in microbiota dynamics. A major challenge, however, is to dissect the cause and effect relationships involved. Invertebrate model organisms such as the fruit fly Drosophila and the nematode Caenorhabditis elegans have been invaluable in studies of the biological mechanisms of aging. Indeed, studies in flies and worms have resulted in the identification of a number of interventions that can slow aging and prolong life span. In this review, we discuss recent work using invertebrate models to provide insight into the interplay between microbiota dynamics, intestinal homeostasis during aging and life span determination. An emerging theme from these studies is that the microbiota contributes to cellular and physiological changes in the aging intestine and, in some cases, age-related shifts in microbiota dynamics can drive health decline in aged animals.     

Thick filament size changes in contraction of human muscles

Summary Measurements done on electron micrographs show that in myofibres with sarcomeres contracted to below 2.1 m, proportional shortening of the A bands occurs. In muscles from patients with idiopathic scoliosis very short A bands are especially prominent.This work was supported by the Muscular Dystrophy Association of America.We wish to thank H. Orgal and Y. Havivi, for their technical assistance, O. Carmi and B. Ghidoni for their help with the measurements and N. Vagenberg for the computer analyses.     

Evidence for a neurological zoom system in vision from angular changes in some receptive fields of single neurons with changes in fixation distance in the human visual cortex

Résumé Dans le cortex visuel humain de 3 champs réceptifs de neurones individuels 2 présentent des changements d'angle correspondant aux changements de perception à distance. Ces changements peuvent être la base neurologique du système perceptif de stabilité, de «zoom» ou de graduation de la vision.     

Age-dependent changes of acid mucopolysaccharide excretion patterns in human urine

Zusammenfassung Die sauren Mucopolysaccharide im Harn von 37 Normalpersonen verschiedenen Alters (Säuglinge bis Erwachsene) wurden säulenchromatographisch fraktioniert und einzeln bestimmt.

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This study was supported by a grant from the Deutsche Forschungsgemeinschaft, Bad Godesberg.     

Aging and TOR: interwoven in the fabric of life

Longstanding results with calorie and growth factor restriction plus recent results with the first interventional drug suggest that retarding the pace of aging to improve the quality of life of older people is at hand. The biological system targeted by these approaches is the target of rapamycin (TOR), which is central for cellular responses to a variety of stimuli including stressors, growth factors, and nutrients and energy states. That the life-extending response to reducing its activity is highly conserved from yeast to mammals is consistent with the evolution of aging as a strategy to preserve reproductive potential of young cells and animals.     

Seasonal changes of circadian rhythms of human birth in northern Finland

Zusammenfassung Die Verteilung der Geburten im finnischen Lappland auf die Tagesstunden zeigt eine jahreszeitliche Schwankung der Phasenlage in der Geburtenrhythmik. Zur Mittwinterzeit fallen die meisten Geburten in die Zeit von 08.00 bis 20.00 Uhr, während sie in den anderen Jahreszeiten auf die Nacht und den Vormittag fallen.

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Supported by a grant from the National Research Council for Sciences (Finland).