Physicochemical properties of pyocin F1.

The physiochemical properties of pyocin F1 were studied. Pyocin F1 consists of flexuous rod-like particles homogenous in size. Each particle was composed of rod and fiber parts. The rod part was 105.5 +/- 9.5 nm long and 10.0 +/- 1.4 nm wide, and showed regular striations amounting to 23 layers. The fiber part was composed of several filaments; the length of the longest filament was 43.0 +/- 12.0 nm. The amino acid composition, the partial specific volume (0.720 ml/g), the sedimentation coefficient (S020,W = 35.1S), and the translational diffusion constant (0.94 +/- 0.01 x 10(-7) cm2/s) were determined. The particle weight was calculated to be 3.23 x 10(6) daltons.     

Inhibitory effect of amines on polar filament extrusion byPlistophora anguillarum spores

In in vitro tests, amines were screened for the inhibition of polar filament extrusion by spores ofPlistophora anguillarum, a microsporidian parasite of the eel. Primary amines having C₈ ⁻ C₁₈ alkyl chains were effective, irrespective of the anions bound. Secondary amines having a branched C₈ chain and tertiary amines having C₁₄−C₁₈ chains were also effective. Asymmetry in side chains seemed to be required for inhibitory action. Quaternary ammonium salts having C₁₂−C₁₆ alkyl chains and some germicides or disinfectants such as cetyl pyridinium chloride and benzethonium chloride were also effective. Diamines and amides were ineffective regardless of the length of their alkyl chins. In in vivo tests, eel larvae-fed for 4 days with a commercial feed supplemented with 5×10⁸ cells of spores and 4g of laurylamine aspartate/100 g feed, and thereafter with the usual commercial feed for 26 days—were not infected.     

Production of prostacyclin-like substance in stroke-prone and stroke-resistant spontaneously hypertensive rats

Activities of aortae to produce prostaglandin (PG) I₂-like substance in stroke-prone spontaneously hypertensive rats (SHRSP), stroke-resistant SHR (SHRSR) and normotensive control rats from the Wistar-Kyoto (WK) colony were compared. PGI₂-like substance was produced by the incubation of the aortic ring in pH 9.0 borate-buffered saline and the amount produced was estimated by comparison of its anti-aggregatory activity with that produced by known amounts of the sodium salt of synthetic PGI₂. Before the development of stroke, amounts of this substance generated in SHRSP and SHRSR were significantly higher than those in WK rats (p<0.01 and p<0.02, respectively). Remarkably reduced capacity to generate PGI₂-like substance was observed in some SHRSP after the development of stroke.     

Enzymes of purine catabolism in soybean plants

Remarkable formation and utilization of allantoin is observedin soybean (Glycine max variety A62-1). To study this, variousenzymes involved in purine catabolism (i.e., xanthine oxidase,uricase and allantoinase) were measured in different regionsof soybean plants during development. Uricase, which catalyzesthe direct formation of allantoin from uric acid, was studiedin detail. The activities of these three enzymes were highest in the rootnodules, indicating that the nodules are the major site of allantoinmetabolism. Radicles only showed appreciable activity about80 hr after the seeds were planted. Allantoinase activity wasdetected in all regions tested, showing that allantoin translocatedfrom the nodules can be metabolized in the roots, stem and leaves.In the nodules, xanthine oxidase was localized in the nuclearfraction, while uricase was mainly restricted to the mitochondrialfraction and allantoinase to the soluble fraction. Uricase was partially purified from the nodules and radicles,respectively. The pH optimum of enzyme from the nodules was9.5, whereas that of enzyme from the radicles was 7.0. The enzymefrom the nodules did not require a cofactor, while that fromthe radicles showed an absolute requirement for a cofactor,which was a low molecular substance easily separable from theapoprotein. Thus, the uricase in nodules differs in chemicalproperties from that in the host plant. The results are discussedin relation to change in the allantoin level in soybean tissues. (Received November 1, 1974; )     

The ultrastructure of the middle cerebral artery and its associated nerve fibers in the squirrel monkey and baboon

This study describes the ultrastructural characteristics of the middle cerebral artery and its related neural elements in the squirrel monkey and baboon. The cytoarchitecture of the M-1 segment as well as that of the smaller extracerebral and intracerebral vessels is comparable in both animals.Smooth muscle elements are occasionally found within the intimai lining. The nerve bundles associated with vessels contain fewer myelinated fibers as the vessel diameter decreases. The cytological relationship between the neural structures and the smooth muscle cells are discussed.     

New peptide alkaloids from Hovenia dulcis and H. tomentella

From the root bark of Hovenia dulcis Thunb. and H. tommentella (Makino) Nakai (Rhamnaceae), three peptide alkaloids, frangulanine, hovenins-A and -B have been isolated. Hovenin-A has been shown to be des-N-methylfrangulanine (II).     

Reduction of severe acute respiratory syndrome coronavirus-2 infectivity by admissible concentration of ozone gas and water

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is causing the global coronavirus disease 2019 (COVID-19) pandemic. Because complete elimination of SARS-CoV-2 appears difficult, decreasing the risk of transmission is important. Treatment with 0.1 and 0.05 ppm ozone gas for 10 and 20 hr, respectively, decreased SARS-CoV-2 infectivity by about 95%. The magnitude of the effect was dependent on humidity. Treatment with 1 and 2 mg/L ozone water for 10 s reduced SARS-CoV-2 infectivity by about 2 and 3 logs, respectively. Our results suggest that low-dose ozone, in the form of gas and water, is effective against SARS-CoV-2.     

Cellular Auxin Homeostasis under High Temperature Is Regulated through a SORTING NEXIN1–Dependent Endosomal Trafficking Pathway

High-temperature-mediated adaptation in plant architecture is linked to the increased synthesis of the phytohormone auxin, which alters cellular auxin homeostasis. The auxin gradient, modulated by cellular auxin homeostasis, plays an important role in regulating the developmental fate of plant organs. Although the signaling mechanism that integrates auxin and high temperature is relatively well understood, the cellular auxin homeostasis mechanism under high temperature is largely unknown. Using the Arabidopsis thaliana root as a model, we demonstrate that under high temperature, roots counterbalance the elevated level of intracellular auxin by promoting shootward auxin efflux in a PIN-FORMED2 (PIN2)-dependent manner. Further analyses revealed that high temperature selectively promotes the retrieval of PIN2 from late endosomes and sorts them to the plasma membrane through an endosomal trafficking pathway dependent on SORTING NEXIN1. Our results demonstrate that recycling endosomal pathway plays an important role in facilitating plants adaptation to increased temperature.