Effects of body and head positions on bilateral difference in tympanic temperatures

We have examined the nonparallel changes in tampanic membrane temperatures (T _ty) from the two ears in response to various changes in body and head positions. Upon assuming a lateral recumbent position, the T _ty on the lower side increased while that on the upper side decreased. Pressure application over a wide area of the lateral chest only caused inconsistent and obscure asymmetric changes in T _ty. A lateral flexion of the head with the subject sitting upright and a rotation of the head to the side in a supine position induced an increase in the T _ty on the lower side compared to that on the upper side. The temperature and blood flow of the forehead often decreased on the lower side and increased on the upper side, although such responses were not always concomitant with the asymmetric changes in T _ty. A dorsal flexion of the head with the subject in a reclining position caused a slight increase in the T _ty, whereas raising the head upright induced a slight decrease in them. Two additional experiments were carried out with single photon emission computed tomography using ^99mTc-hexamethylpropyleneamine oxime as tracer, and a slight, relative decrease in counts was noted in the right hemisphere during rotation of the head to the right. These results would strongly suggest that unilateral increases and decreases in T _ty could have been caused by one-sided decreases and increases, respectively, in blood flow to the brain and/or the tympanic membrane, induced by a vasomotor reflex involving vestibular stimulation.     

Differentiation of Rickettsia japonica by Restriction Endonuclease Fragment Length Polymorphism Using Products of Polymerase Chain Reaction Amplification with Rickettsia rickettsii 190-Kilodalton Surface Antigen Gene Primers

Restriction fragment length polymorphism of polymerase chain reaction (PCR) amplification products differentiated Rickettsia japonica, a causative agent of Oriental spotted fever, from other spotted fever group (SFG) rickettsiae. Primer pair Rr190. 70p and Rr190. 602n of R. rickettsii 190-kDa antigen gene sequence primed genomic DNAs obtained from R. japonica, type strain YH and strains NT, NK, YKI, and TKN. The products were cleaved by PstI but not by AfaI restriction endonuclease. The PstI digestion pattern of PCR-products amplified from all strains of R. japonica was identical and easily differentiated from that of other SFG rickettsiae. The present study demonstrated a genotypic difference between R. japonica and other pathogenic SFG rickettsiae.     

A Parvalbumin-Like Calcium-Binding Protein Is Present in Plant Leaves

A protein with relatively high homology in its N-terminal aminoacid sequence to animal parvalbumin and oncomodulin has beenidentified in leaves of rice (Oryza sativa L.). The PV-likeprotein has a relative molecular mass of 27,000 and an isoelectricpoint of 5.0. This protein was partially purified by ion-exchangechromatography, and the purified protein was found to have Ca²⁺-bindingactivity in a microscale Ca²⁺-binding assay. Furthermore, anantiserum raised against a synthetic oligopeptide based on theN-terminal amino acid sequence of this protein cross-reactedwith protein not only from rice but also from other monocotyledonousplants. (Received October 17, 1990; Accepted October 17, 1991)     

Biological species ofArmillaria and their mycoparasitic associations withRhodophyllus abortivus in Hokkaido

Specimens of basidiomes and/or rhizomorphs ofArmillaria mellea complex and basidiomes ofRhodophyllus abortivus, developing on the same decaying stumps or stems of forest trees, were collected in three forests in Hokkaido. Normal basidiomes ofR. abortivus were found near to, but free from, the rhizomorphs and/or basidiomes ofArmillaria, while abnormal basidiomes, as carpophoroid forms, were developed on the rhizomorphs ofArmillaria. Of three mycoparasiticArmillaria isolates found withR. abortivus, one was identified asA. gallica and two asA. jezoensis. The isolates ofR. abortivus showed excellent mycelial growth and rhizomorph formation on PDA. However, on MDA, RMDA and BMDA, they showed poor aerial mycelia growth and no rhizomorphs. In the contrapositional cultures, the growth ofA. gallica was completely inhibited byR. abortivus on PDA but only slightly inhibited on MDA and RMDA. On the other hand, mutual inhibition at a distance was observed on BMDA. The mycelial growth and rhizomorph formation inA. jezoensis were severely inhibited by the colony ofR. abortivus on PDA, but only slightly inhibited on MDA. On RMDA and BMDA, the colonies of twoArmillaria species andR. abortivus showed mutual inhibition at a distance and apparent rhizomorph formation by bothArmillaria species.     

Chemotaxis towards inorganic phosphate in the red tide alga Chattonella antiqua

The red tide flagellate, Chattonella antiqua, was shown to beattracted to inorganic phosphate in both aged seawater and artificialseawater by well-test assays.     

Expression of an ABA-induced gene of tomato in transgenic tobacco during periods of water deficit

The gene le25 is an abscisic acid (ABA)-induced gene of tomatowhich is expressed both in wilted vegetative organs and developingseeds. Spatial and temporal expression was analysed in tobaccoplants transformed with a chimeric gene in which 5'-upstreamDNA sequences of le25 were fused to the E. coli uidA gene, whichencodes ß-glucuronidase (GUS). Histochemical stainingrevealed that GUS was expressed in all tissues of vegetativeorgans in response to water deficit. Exogenous ABA induced expressionto a lesser extent, even though ABA content was the same asdroughtstressed leaves, indicating a difference in responseto endogenous ABA compared to exogenous ABA. Water-deficit-inducedGUS expression in floral tissues was examined in pre-anthesisfloral buds from four different stages (I–IV; 11, 16,33, 49 mm bud length, respectively). While non-stressed floralorgans showed no GUS activity except in pollen at stages IIIand IV, GUS activity was water-deficit-induced in sepals ofall stages, petals of stage II, and stigmas of stage II andIII. In seeds, GUS activity was detected in both the embryoand endosperm at 15 d post-anthesis, which coincided with alarge increase in the concentration of ABA in the seed. In transgenicplants, the le25 5'-flanking DNA drove expression of GUS duringwater deficit in two modes: non-tissue-specific expression invegetative organs, and tissue-specific expression in reproductiveorgans. The location of GUS activity indicated that ABA concentrationis elevated throughout the tissues of the leaf during periodsof water deficit. Key words: Tomato, ABA, drought stress, lea gene, water deficit     

Characterization of a Dopamine-Releasing Action of 6R-l-erythro-Tetrahydrobiopterin: Comparison with a 6S-Form

Abstract: 6R-l -erythro-Tetrahydrobiopterin (6R-BH₄) is a cofactor for aromatic l -amino acid hydroxylases and nitric oxide synthase. Recently, we have reported that independently of its cofactor activities, 6R-BH₄ acts from the outside of neurons in the brain to enhance the release of monoamine neurotransmitters such as dopamine. To characterize the pharmacological properties of the action, we examined the effects of 6S-BH₄, a diastereoisomer of 6R-BH₄, on dopamine release in the rat striatum by using brain microdialysis and compared its effects with those of 6R-BH₄. Perfusion of 6S-BH₄ or 6R-BH₄ through the dialysis probe increased extracellular dopamine levels (an index of in vivo dopamine release) concentration dependently; the maximal increase by 6S-BH₄, was one-sixth of that by 6R-BH₄. 6S-BH₄ increased extracellular DOPA levels in the presence of NSD 1015, an inhibitor of aromatic l -amino acid decarboxylase (an index of in vivo tyrosine hydroxylase activity), to an extent similar to the increase induced by 6R-BH₄. The increase in the DOPA levels induced by either of the pteridines was abolished after pretreatment of rats with α-methyl-p-tyrosine (an inhibitor of tyrosine hydroxylase). Under the same conditions, the 6S-BH₄-induced dopamine release was abolished, but most of the 6R-BH₄-induced increase persisted. Coadministration of 6S-BH₄ with 6R-BH₄ inhibited the increase in dopamine release induced by 6R-BH₄ alone. These results show that 6R-BH₄ stimulates dopamine release by acting at the specific recognition site on the neuronal membrane, and that 6S-BH₄ acts as an antagonist of 6R-BH₄ at this site, although it has cofactor activities.     

Novel function of guanidine hydrochloride in reverse micellar extraction of lysozyme from chicken egg white

The efficiency of guanidine hydrochloride (GuHCl) addition in the suppression of gel formation and the extraction of lysozyme during reverse micellar extraction from chicken egg white was investigated. A low concentration of GuHCl in the feed permitted the successful extraction of lysozyme in its native form without gel formation, which is perceived as a novel function of GuHCl. The highest recovery and specific activity of lysozyme were obtained at a GuHCl concentration of 0.06 M in 25 mM AOT reverse micellar extraction from 20-fold-diluted natural chicken egg white. Lysozyme and ovalbumin CD spectra in the corresponding GuHCl aqueous solutions revealed no changes in the higher order structures of the proteins. Furthermore, the specific activity of lysozyme in the feed was well preserved in the GuHCl system. (c) 1995 John Wiley & Sons, Inc.     

FISH analysis of the telomere sequences of bulldog ants (Myrmecia: Formicidae)

Chromosomes from several species of ants from the genus Myrmecia were hybridized with deoxyoligomer probes of either (T₂AG₂)₇, the putative insect telomere repeat sequence, or (T₂AG₃)₇, the vertebrate telomere repeat sequence. While both sequence hibridized over a range of stringency conditions, (T₂AG₂)_n was clearly the predominant sequence at the termini of the Myrmecia chromosomes. No interstitial sites of either sequence were detected. The genus Myrmecia has a wide range of karyotypes, with chromosome numbers ranging from 2n=2–84. It has been hypothesized that the ancestral karyotype was 2n=4 and karyotype evolution proceeded with an increase in chromosome number. In the absence of detectable interstitial sites of telomere sequence, it is interesting to speculate on the origin of the new telomeres as the chromosome numbers increased.