Analogues of Phenoxyacetic Acid and the Generation of Calluses from Seeds of Indica Rice

In a search for callus-inducing compounds for indica rice thatare superior in this regard to 2,4-dichlorophenoxyacetic acid(2,4-D), we tested 13 derivatives of phenoxyacetic acids, namely,mono- and di- chloro-, mononitro- and 4-halogeno-substitutedphenoxyacetic acids for their ability to stimulate the inductionof calluses from mature seeds of rice (Oryza sativa L. cv. Chiemchanh). Five analogues of benzoic acid were also tested. Thecallus-forming ability and the optimal concentration for inductionof calluses were differed from compound to compound. The optimal concentration for callus induction of 4-fluorophenoxyaceticacid (4FPA) was relatively high (250 µM), but its callus-formingactivity was stronger than that of 2,4-D, even when comparedwith 2,4-D at its optimal concentration (50 µM). 4FPA-inducedcalluses retained their regenerative ability for at least 15months with 9 subcultures, while calluses induced by 2,4-D losttheir regenerative ability after 3 subcultures. 4FPA-induced calluses showed higher regenerative ability thandid calluses induced by 2,4-D, in almost all of 20 varietiesof indica tested, including three indica-japonica hybrids. ³Present address: Kibun Co.Ltd., Ginza, Tokyo, 104 Japan ⁴Present address: Hyogo Agricultural Research Institute, Kasai,Hyogo, 679-01 Japan (Received October 25, 1989; Accepted May 17, 1990)     

Effect of DMSO on PCR of Porphyra yezoensis (Rhodophyta) gene

In order to improve the predictability ofresults of PCR with Porphyra yezoensisUeda genes, a study was made of possiblemodifications to the basic PCR protocol. DMSO used as an adjuvant considerablyincreased amplification efficiency andspecificity of PCR, the optimalconcentration being 5%. This protocolallowed for DNA templates with a high GCcontent to be amplified by PCR withoutproblem.     

Interactive drives from two brain stem premotor nuclei are essential to support rat tail sympathetic activity

Anatomical studies indicate that sympathetic preganglionic neurons receive inputs from several brain stem cell groups, but the functional significance of this organization for vasomotor control is not known. We studied the roles of two brain stem premotor cell groups, the medullary raphé and the rostral ventrolateral medulla (RVLM), in determining the activity of sympathetic vasomotor supply to the tail of urethane-anesthetized, artificially ventilated rats. Chemical inactivation of either RVLM (bilaterally) or raphé cells by microinjecting glycine (120-200 nl, 0.5 M) or muscimol (40-160 nl, 2.1-8 mM) was sufficient to inhibit ongoing tail sympathetic fiber activity and to block its normally strong response to mild cooling via the trunk skin (reducing rectal temperature from 38.5 to 37 degrees C). After bilateral RVLM inactivation, tail sympathetic fibers could still be excited by chemical stimulation of raphé neurons (l-glutamate, 120 nl, 50 mM), and strong cooling (rectal temperature approximately 33 degrees C) caused a low level of ongoing activity. After chemical inhibition of raphé neurons, however, neither strong cooling nor chemical stimulation of RVLM neurons activated tail sympathetic fibers. Electrical stimulation of the RVLM elicited tail sympathetic fiber volleys before and after local anesthesia of the raphé (150-500 nl of 5% tetracaine), demonstrating the existence of an independent descending excitatory pathway from the RVLM. The data show that neurons in both the medullary raphé and the RVLM, acting together, provide the essential drive to support vasomotor tone to the tail. Inputs from these two premotor nuclei interact in a mutually facilitatory manner to determine tonic, and cold-induced, tail sympathetic activity.     

Status of Bone Allografting in Japan – Nation-Wide Survey of Bone Grafting Performed from 1995 through 1999

We report the status of bone allografting in Japan on the basis of the information obtained through questionnaires performed by the Japanese Orthopaedic Association (JOA). JOA performed a nation-wide survey in 2000, in order to clarify the current status of musculoskeletal tissue grafting in the orthopaedic practices in Japan. Conducted period was for 5 years from 1995 to 1999. As the results of this survey, it had been clarified that 92,984 bone graftings, which included autografts, allografts and synthetic bone substitutes, were performed during conducted 5 years. While the allografts were used only in 3,212 cases (3%), autograftings were performed in 64,193 cases (69%), synthetic bone substitutes were used in 25,576 cases (28%) in this series. The proportion of the number of operations for use bone substitutes increased every year, whereas that autografting decreased. The proportion of the number of allografting remained almost unaltered. Of the 706 institutions which answered to have experiences of tissue grafting, only 193 (27%) performed allograft.Since Kitasato University Hospital Bone Bank was developed in 1971, we have applied to clinical while doing basic research for preserved bone allograft. When extensive bone graft is required, allograft is very useful. In Japan, however, allograft is not performed widely. The foundation of regional bone banks is expected to resolve this problem. Since excision of bone preparations from cadaver donors is not common, bone allografts are not supplied sufficiently at present. It is needed to develop a network connecting bone banks in Japan. The enlightenment activities to the ordinary people and medical institutions will also be required.