Immunohistochemical demonstration of glucagon in an A2-cell carcinoma

Zusammenfassung Glucagon ist durch Immunohisto-fluoreszenz in einem A₂-Zell-Carcinom der menschlichen Bauchspeicheldrüse und in Metastasen in der Leber entdeckt worden.

---

---

Acknowledgments. Grant support from the Swedish Medical Research Council No. B73-04X-1007-08 and B73-12X-102-09B, Albert Påhlsson's Foundation, Riksföreningen mot Cancer, «Fonden för Stor-Köpenhamn, Grönland och Färöarna», and «Landsföreningen för kräftans bekämpelse».     

Amoeboid movement: A review and proposal of a ‘membrane ratchet’ model

Summary Diverse cell types, including Amoebae, leukocytes, embryonic cells and tumour cells move about on solid surfaces to accomplish such activities as feeding, bacterial destruction, embryological development and metastasis. Theories of the mechanism of this movement are reviewed and a model is proposed which invokes the existence of specific, laterally mobile, transmembranous structures in the cell membrane, which are reversibly adhesive for both the contractile apparatus of the cell internally, and the substratum externally. By this model, the movement of all these cell types can be explained.     

Effects of pCai and pHi on cell-to-cell coupling

Summary Internal longitudinal resistance (r_i), a determinant of cardiac conduction, is affected by changes in intracellular calcium and protons. However, the role and mechanism by which H⁺ and Ca²⁺ may modulate r_i is uncertain. Cable analysis was performed in cardiac Purkinje fibers to measure r_i during various interventions. In some experiments, intracellular pH (pH_i) was recorded simultaneously to study the pH_i-r_i relation. Both intracellular Ca²⁺ and H⁺ independently modified r_i. However, internal resistance of cardiac fibers was insensitive to pH_i changes compared to other tissues. A latent period preceded the pH_i-related changes in r_i and the amount of change depended upon methodology. The results suggest that direct action of protons on r_i may be subordinate to other regulatory processes. Ionic regulation of internal longitudinal resistance may occur by more than one mechanism: i) direct cationic binding to sites on junctional membrane proteins; and ii) H⁺- or Ca²⁺-dependent phosphorylation of junctional proteins.     

Differential effects of prostaglandins and isoproterenol on cAMP content and Na, K pump activity in rat submandibular acini

The beta-adrenergic agonist isoproterenol and prostaglandins E1 and E2 (but not F2 alpha) increased the cAMP content of rat submandibular acini in vitro, but only isoproterenol enhanced ouabain-sensitive 86Rb (K) uptake. These findings suggest that cAMP is not involved in the activation of the Na, K pump in salivary cells.     

3-Amino-3-deoxy-D-glucose: an antibiotic produced by a deep-sea bacterium

Gram-positive bacteria isolated from deep-sea sediments of the Pacific basin showed considerable antibacterial activity. A Bacillus strain, isolated from a sediment sample collected at a depth of 4310 m, was shown to produce 3-amino-3-deoxy-D-glucose, a known antibiotic.