‘Clear’ cells in the normal cervical epithelium of the mouse

Résumé Un examen au microscope électronique des cellules «claires» de l'épithelium cervical de la souris a révélé qu'il leur manque les granules caractéristiques de Langerhans décrites dans les cellules correspondantes de l'exocol humain.     

Nervous activity of the frog's epiphysis cerebri in relation to illumination

Zusammenfassung Die proximale Anlage des lichtempfindlichen Pinealorgans adulter Anuren zeigt eine Daueraktivität, die durch Belichtung gehemmt wird. Die mit Hilfe von Stahlmikroelektroden bestimmte absolute Schwelle einzelner Neurone des Organs liegt zwischen 10^–5 und 10^–6 lm/m². Bei Belichtung vermindert sich die Impulsfrequenz der Daueraktivität linear mit dem Logarithmus der Beleuchtungsstärke. Der Halbwert der Entladungsfrequenz liegt bei 10^–2 lm/m². Oberhalb 10 lm/m² ist keine Impulsaktivität zu beobachten.     

Functional anatomy of frog's taste organs

Résumé Dans les bourgeons gustatifs deRana pipiens deux groupes de cellules ont été découverts. Le premier est directement en relation avec la réception de stimuli, tandis que le second ne comprend que des cellules d'association. Les cellules sensorielles offrent des contacts synaptiques avec les fibres sensorielles.

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This work represents a portion of a thesis submitted byR. DeHan in partial fulfillment for the degree of doctor of philosophy.     

Effect of autonomic drugs on Ca-induced contractures of the frog's ventricle

Zusammenfassung Kontrakturen des Froschventrikels in Ringerlösung mit hoher Ca-Konzentration werden durch Azetylcholin verstärkt, während Adrenalin Erschlaffung herbeiführt. Diese Wirkungen sind nicht mit Änderungen des Membranpotentials verbunden und sind vielleicht die Folge sehr kleiner Änderungen des Ca-Austausches. Bei niederer Ca-Konzentration kann Azetylcholin auch Erschlaffung erzeugen.     

The distribution of endocrine-like cells in the human male and female urethral epithelium

Summary Histochemical and electron microscopic techniques have been used to study the nature and distribution of fluorescent, endocrine-like cells in the urethra of the human male and female. The confinement of such cells to specific regions of the urethra is discussed in relation to the embryological development of this part of the urinary tract.     

The distribution of endocrine-like cells in the human male and female urethral epithelium.

Histochemical and electron microscopic techniques have been used to study the nature and distribution of fluorescent, endocrine-like cells in the urethra of the human male and female. The confinement of such cells to specific regions of the urethra is discussed in relation to the embryological development of this part of the urinary tract.     

Multinucleated cells in the retinal pigment epithelium: A scanning electron microscopic study

Summary Multinucleated cells in the retinal pigment epithelium of the albino rat are shown with the scanning electron microscope beside normal mononucleated cells. We suggest that such elements are formed during foetal life, owing to the absence of any mitotic activity in adult rats.     

Determination of odour affinities based on the dose-response relationships of the frog's electro-olfactogram

Summary Electro-olfactograms (EOG's) recorded from the frog's olfactory epithelium for 11 substances were used to calculate dissociation constants which in turn serve as an index for the affinity between odorant and receptor site. These constants were calculated with and without a correction for the odour partition between water and air. For a homologous series of 7 n-alcohols these values decrease up to 1-heptanol. The dose-response relationships were based on the peaks of the EOG's since the peak/plateau-ratio was concentration-dependent for some of the substances.This work was supported by Z.W.O. grant number 12-24-12 of the Dutch Government.     

Morphological alterations of basal cells of vaginal epithelium in neonatally oestrogenized mice

Summary Neonatal oestrogen treatment results in the development of vaginal cancers in the mouse. A morphological sign which probably indicated early invasion of altered vaginal cells into the stroma through gaps in the basal lamina was first seen at 10 months of age in neonatally oestrogenized C57Black mice. Prior to this, a decrease in the numbers of cellular attachment organelles such as half desmosomes and desmosomes was observed by 3 months.This work was supported by Contract NO1-CP-55650 of National Cancer Institute, National Institute of Health, Public Health Service, USA, and by a Grant-in-Aid for Scientific Research from the Ministry of Education, Science and Culture of Japan.     

The intestinal epithelium tuft cells: specification and function

The intestinal epithelium, composed of at least seven differentiated cell types, represents an extraordinary model to understand the details of multi-lineage differentiation, a question that is highly relevant in developmental biology as well as for clinical applications. This review focuses on intestinal epithelial tuft cells that have been acknowledged as a separate entity for more than 60?years but whose function remains a mystery. We discuss what is currently known about the molecular basis of tuft cell fate and differentiation and why elucidating tuft cell function has been so difficult. Finally, we summarize the current hypotheses on their potential involvement in diseases of the gastro-intestinal tract.