Electric Currents around Growing Trichoderma Hyphae, before and after Photoinduction of Conidiation

Electric currents were measured around Trichoderma harzianum (Rifai) hyphae using an extracellular vibrating electrode. A steady current enters growing hyphal tips and along the side of the apical millimeter. In addition, outward currents were detected at about one-ninth of the locations tested, 60 to 150 minutes after illumination but not in dark controls. This sporadic, localized outward current pattern might be an early biophysical response to blue light.     

Effect of culture conditions on synthesis of L-asparaginase by Escherichia coli A-1.

The nutritional requirements and culture conditions affecting biosynthesis of L-asparaginase in a mutant of Escherichia coli HAP designated strain A-1 were studied. Asparaginase activity was increased by the addition of L-glutamic acid, L-glutamine, or commercial-grade monosodium glutamate. The rate of enzyme synthesis was dependent on the interaction between the pH of the culture and the amount of oxygen dissolved in the medium. A critical oxygen transfer rate essential for asparaginase formation was identified, and a fermentation procedure is described in which enzyme synthesis is controlled by aeration rate. Enhancement of L-asparaginase activity by monosodium glutamate was inhibited by the presence of glucose, culture pH, chloramphenicol, and oxygen dissolved in the fermentation medium.     

Natural H Currents Traverse Growing Roots and Root Hairs of Barley (Hordeum vulgare L.)

With the aid of an extracellular vibrating electrode, natural electric fields were detected and measured in the medium near growing roots and root hairs of barley seedlings. An exploration of these fields indicates that both the root as a whole, as well as individual root hairs, drive large steady currents through themselves. Current consistently enters both the main elongation zone of the root as well as the growing tips of elongating root hairs; it leaves the surface of the root beneath the root hairs. These currents enter with a density of about 2 microamperes per square centimeter, leave with a density of about 0.5 to 1 microampere per square centimeter, and total about 30 nanoamperes.     

A new species of Penstemon (Scrophulariaceae) from Wyoming

A new species from Wyoming,Penstemon gibbensii, is described and contrasted to related species.     

Response properties of thick myelinated group II afferents in the medial articular nerve of normal and inflamed knee joints of the cat.

This study investigated the responses to innocuous and noxious mechanical stimuli of joint mechanoreceptors with thick myelinated articular afferents (conduction velocities 21-65 m/sec) in the medial articular nerve of the cat's knee. In nine experiments, we examined whether acute arthritis would modify the discharge properties. The vast majority of the group II afferents were excited by gentle local stimuli and by movements in the working range of the knee. Although they encoded pressure and particular movement stimuli up to the noxious range, their responses were more closely related to the particular type of stimulus (e.g., a movement in a specific direction) than to its intensity (innocuous vs. noxious). In inflamed joints, the response patterns of group II units were similar with regard to local mechanical thresholds, thresholds for passive movements, and patterns of responses to passive movements. In both situations, most units had no resting activity. These results suggest that articular group II afferents do not play a significant role in nociception. Rather, they subserve proprioceptive functions such as deep pressure sensation and kinesthesia in normal as well as inflamed joints.     

Insulin-like immunoreactivity in the human brain

Summary The localization and regional distribution of insulin-like immunoreactivity (IRI) was studied in human brain autopsy material using the indirect immunofluorescence technique. A positive reaction for IRI could be observed in many neurons of the hypothalamus, the hippocampus, corpus amygdaloideum, medulla oblongata (especially within the nuclei of cranial nerves IX, X and XII), and the cerebral cortex, whereas the cerebellar cortex was lacking in immunohistochemically detectable insulin-like material. No nerve fibres containing polypeptides could be revealed. Additionally, the inuslin content of various brain regions was estimated by radioimmunosassay. Insulin concentrations in human nervous tissue were found to be elevated in comparison to blood plasma levels.The present investigation was supported by the HFR Neurobiologie und Hirnforschung and the HFR Diabetes mellitus und Fettstoffwechselstörungen of the GDR (Ministries of Higher Education and Health respectively) and the Finnish Ministry of Education     

Pyridostigmine improves cardiac function and rhythmicity through RyR2 stabilization and inhibition of STIM1-mediated calcium entry in heart failure

Heart failure (HF) is characterized by asymmetrical autonomic balance. Treatments to restore parasympathetic activity in human heart failure trials have shown beneficial effects. However, mechanisms of parasympathetic-mediated improvement in cardiac function remain unclear. The present study examined the effects and underpinning mechanisms of chronic treatment with the cholinesterase inhibitor, pyridostigmine (PYR), in pressure overload HF induced by transverse aortic constriction (TAC) in mice. TAC mice exhibited characteristic adverse structural (left ventricular hypertrophy) and functional remodelling (reduced ejection fraction, altered myocyte calcium (Ca) handling, increased arrhythmogenesis) with enhanced predisposition to arrhythmogenic aberrant sarcoplasmic reticulum (SR) Ca release, cardiac ryanodine receptor (RyR2) hyper-phosphorylation and up-regulated store-operated Ca entry (SOCE). PYR treatment resulted in improved cardiac contractile performance and rhythmic activity relative to untreated TAC mice. Chronic PYR treatment inhibited altered intracellular Ca handling by alleviating aberrant Ca release and diminishing pathologically enhanced SOCE in TAC myocytes. At the molecular level, these PYR-induced changes in Ca handling were associated with reductions of pathologically enhanced phosphorylation of RyR2 serine-2814 and STIM1 expression in HF myocytes. These results suggest that chronic cholinergic augmentation alleviates HF via normalization of both canonical RyR2-mediated SR Ca release and non-canonical hypertrophic Ca signaling via STIM1-dependent SOCE.