Isolation and Structure Elucidation of Neokadsuranic Acid A, the First Triterpenoid with the 14 (13-->12) abeo Lanostane Skeleton, and (24Z)-3-Oxo-lanosta-8,24-dien-26-oic Acid1

Neokadsuranic acid A, which is the first triterpenoid with the 14(13-->12) ABEO lanostane skeleton, was isolated from KADSURA HETEROCLITA together with (24 Z)-3-oxo-lanosta-8,24-dien-26-oic acid. The present paper deals with the isolation and structure elucidation of these two new compounds.     

Ultrasonic vocalizations and aggressive behavior in male rats

The aim of the present study was to know whether 22-28-kHz vocalizations have any communicatory role in the regulation of aggressive behavior in male rats of the Wistar strain. In pairs of intact rats 22-28-kHz vocalizations showed a positive correlation with the extent of aggressive behavior. The pattern of aggressive behavior during ultrasonic vocalizations was different from that just before and just after the vocalizations. However, surgically deafened rats were less active in aggressive behavior and more active in ambulatory activity in the open field than the controls. Muted rats were not different from the controls in both aggressive behavior and ambulatory activity. The present result that the deprivation of ultrasonic signals failed to increase aggressive behavior does not support the classical hypothesis that ultrasonic vocalizations inhibit the initiation of aggressive behavior. It is concluded that ultrasounds emitted during aggressive encounters may have little communicative value in male rats.     

Contribution of Asian mouse subspecies Mus musculus molossinus to genomic constitution of strain C57BL/6J, as defined by BAC-end sequence-SNP analysis

MSM/Ms is an inbred strain derived from the Japanese wild mouse, Mus musculus molossinus. It is believed that subspecies molossinus has contributed substantially to the genome constitution of common laboratory strains of mice, although the majority of their genome is derived from the west European M. m. domesticus. Information on the molossinus genome is thus essential not only for genetic studies involving molossinus but also for characterization of common laboratory strains. Here, we report the construction of an arrayed bacterial artificial chromosome (BAC) library from male MSM/Ms genomic DNA, covering approximately 1x genome equivalent. Both ends of 176,256 BAC clone inserts were sequenced, and 62,988 BAC-end sequence (BES) pairs were mapped onto the C57BL/6J genome (NCBI mouse Build 30), covering 2,228,164 kbp or 89% of the total genome. Taking advantage of the BES map data, we established a computer-based clone screening system. Comparison of the MSM/Ms and C57BL/6J sequences revealed 489,200 candidate single nucleotide polymorphisms (SNPs) in 51,137,941 bp sequenced. The overall nucleotide substitution rate was as high as 0.0096. The distribution of SNPs along the C57BL/6J genome was not uniform: The majority of the genome showed a high SNP rate, and only 5.2% of the genome showed an extremely low SNP rate (percentage identity = 0.9997); these sequences are likely derived from the molossinus genome.     

Histological examination of beta-tricalcium phosphate graft in human femur

Prominent osteoconductive activity and the biodegradable nature of beta tricalcium phosphate (beta-TCP) for bone grafts in animal experiments has been reported. A new type of beta-TCP has been manufactured at extraordinarily high purity and has been available as potent bone grafting substitute for clinical use. The histological features of grafted beta-TCP in human bone have been analyzed. A 33-year-old female with a bone tumor of the proximal femur underwent curettage and beta-TCP graft under the diagnosis of probable benign fibrous dysplasia. Four weeks later, the proximal femur, including the grafted beta-TCP was resected because of the final diagnosis of the curettaged materials was osteosarcoma. The resected specimen revealed abundant direct new bone apposition on beta-TCP. There was no cartilaginous tissue or enchondral ossification. Bone formation was more prominent in the periphery of the grafted area than in the center. There was a considerable number of osteoclast-like giant cells surrounding the beta-TCP. This case illustrated that highly purified beta-TCP had prominent osteoconductive activity and biodegradable nature in human bone.     

Rhythmical contractions in pulmonary arteries of monocrotaline-induced pulmonary hypertensive rats

Rhythmical contractions accompanied by an increase in cytosolic Ca2+ concentrations were produced in ring preparations of endothelium-denuded pulmonary arteries from monocrotaline-treated rats, but not in those from vehicle-treated rats, 2-3 h after a resting tension of 15 mN (150-180% of the initial wall length of the artery) was applied. The rhythmical contractions were abolished by nicardipine and ryanodine. Cyclopiazonic acid reduced the relaxation phase of the rhythmical contractions, finally leading to a sustained contraction. Similarly, apamin caused a sustained contraction, whereas charybdotoxin increased the amplitude of the rhythmical contractions. Glibenclamide had no apparent effects on them. Indomethacin and the prostaglandin H2/thromboxane A2 receptor antagonist SQ29548 abolished the rhythmical contractions and reduced the tension, but the thromboxane synthase inhibitor ozagrel had no effect. These results suggest that optimal stretch induces rhythmical contractions in the pulmonary arteries of monocrotaline-induced pulmonary hypertensive rats, to which both Ca2+ influx through voltage-operated Ca2+ channels and Ca2+ release from the endoplasmic reticulum seem to contribute. It is also suggested that small-conductance Ca(2+)-activated K+ channels participate in the relaxation phase of rhythmical contractions. Furthermore, prostaglandin H2 released from nonendothelial cells is likely to play a pivotal role in the induction of rhythmical contractions.     

Selection of stereotyped VH81X-{micro}H chains via pre-B cell receptor early in ontogeny and their conservation in adults by marginal zone B cells

The pre-B cell receptor (preBCR) plays critical roles in early B cell differentiation. It has been shown that not all muH chains are capable of pairing with surrogate light (SL) chains to form preBCR. Here, we established a novel system to differentially identify two types of early pre-B cell populations in bone marrow and fetal liver of mice, one producing SL-pairing muH chains and the other producing SL-non-pairing muH chains. The former population accounted for 80% of all the early pre-B cells in adult bone marrow, while it accounted for only 20% of those in fetal liver. Comparison of the two types of pre-B cell populations in fetal liver revealed the structural difference between SL-pairing and -non-pairing muH chains encoded by the V(H)81X segment that was most frequently utilized in fetal liver pre-B cells but rarely expressed by B cells generated in adults. PreBCR played an important role in the positive selection of V(H)81X-muH chains carrying the characteristic sequences of the complementarity-determining region 3 with little or no nibbling or N nucleotide addition, leading to their predominance in neonatal splenic B cells. These fetal-type V(H)81X-muH chains were also detected in adult spleen, but almost exclusively in marginal zone (MZ) B cells in contrast to the adult-type V(H)81X-muH chains. This strongly suggests that neonatally generated and selected B cells expressing the stereotyped V(H)81X-muH chains are maintained in the adult MZ and could function as innate-like lymphocytes.     

Clinical application of rapid assay of interleukin-6 in influenza-associated encephalopathy

The characteristics of influenza-associated encephalopathy is the high mortality and nimble progress with coma which appears in general cases within 48 hours. Most of patients show no abnormalities in the standard blood checks on admission or in early stage. In this study we investigated if a rapid assay of interleukin (IL)-6 is useful in influenza-associated encephalopathy in early stages. The levels of IL-6 in patients with influenza-associated encephalopathy did not show any significant difference compared with those in patients with febrile convulsion and rotavirus-associated convulsion. However the levels of IL-6 in severe cases were significantly higher than those of mild cases with influenza-associated encephalopathy. Consequently the rapid assay of serum IL-6 is useful to evaluate and decide the therapies.     

The effects of nucleotides and potassium channel openers on the SUR2A/Kir6.2 complex K+ channel expressed in a mammalian cell line, HEK293T cells

 The effects of potassium channel opening drugs and intracellular nucleotides on the ATP-sensitive K+ (K_ATP) channel composed of SUR2A and Kir6.2 in HEK293T cells were examined using the patch-clamp technique. The SUR2A/Kir6.2 channel was activated effectively by pinacidil, marginally by nicorandil but not by diazoxide. The pinacidil-activated channel currents were inhibited by glibenclamide with a K _i value of 160 nM. Upon formation of inside-out (I-O) patches, spontaneous openings of the channels appeared, which were inhibited by intracellular ATP (ATP_i) equipotently in the presence and in the absence of intracellular Mg²⁺ (Mg²⁺ _i). The channel activity ran-down gradually in I-O patches. The run-down channels could be reactivated by ATP_i only in the presence of Mg²⁺ _i. Uridine 5’-diphosphate (UDP) antagonized the ATP_i-mediated inhibition of the channel activity before run-down. After run-down, UDP activated the channel without antagonizing ATP_i-mediated channel inhibition. Thus, the SUR2A/Kir6.2 reproduced the major properties of the native cardiac K_ATP channel well in terms of nucleotide regulation and pharmacology, and therefore can be a useful tool with which to elucidate the molecular mechanisms characterizing the K_ATP channel. Received: 24 October 1997 / Received after revision and accepted: 4 December 1997