The beta-isopropylmalate dehydrogenase (2-hydroxy-4-methyl-3-carboxyvalerate: NAD+ oxidoreductase, EC 1.1.1.85) gene from Baccilus coagulans was cloned and expressed in Escherichia coli C600, using pBR322 as a vector plasmid. The B. coagulans enzyme was purified to a homogeneous state from the E. coli carrying a pBR322 - the B. coaglulans enzyme gene hybrid plasmid. The enzyme consists of two subunits of equal molecular weight (4.4 X 10(4) ). The enzyme activity was stimulated by 0.5 mM Mn2+, Mg2+ and Co2+. The enzyme was strongly inhibited by 0.2 mM p-chloromercuribenzoate and the inhibition was completely recovered by 1 mM dithiothreitol. The B. coagulans enzyme was thermostabilized by 1.5 M NaCl. The B. coagulans enzyme is a composite of alpha-helix, beta-sheet and remainder. The secondary structure of the enzyme was appreciably altered by 0.5 mM MgCl2 and 1.5 M NaCl.

3-Isopropylmalate Dehydrogenase↗

PubMed1984

env-Related leukemogenic genes (gp55 genes) of two closely related polycythemic strains of Friend spleen focus-forming virus possess different recombination points with an endogenous mink cell focus-forming virus env gene.

The unintegrated circular provival DNA of the replication-competent, helper Friend murine leukemia virus (F-MuLV) in a polycythemic strain of Friend leukemia virus complex (FLV, K-1 strain) was molecularly cloned after insertion into the EcoRI site of the plasmid pBR322. The nucleotide sequence of its env gene has been determined. Sequences of this F-MuLV env gene, and the previously reported env-related gene (gp55 gene) of Friend spleen focus-forming virus (SFFV) (K-1 strain) were compared to that of the same gene of the other polycythemic SFFV isolate, SFFV (502), recently reported by Clark and Mak. The gp55 genes of the two SFFV isolates are almost identical to each other and have several common characteristic structures. However, the two gp55 genes are different in that the gp55 gene of SFFV (K-1) has a longer nonecotropic MuLV env sequence than that of SFFV (502). This finding may suggest that each SFFV isolate has been generated independently by recombination between a putative defective variant of F-MuLV and an endogenous mink cell focus-forming virus env sequence.

Amino Acid Sequence↗

PubMed1984

Significant coronary artery disease detected by amyl nitrite and systolic time intervals.

The relation between changes in left ventricular systolic time intervals with amyl nitrite (AN) inhalation and the severity of coronary artery disease (CAD) was evaluated in 77 patients who underwent catheterization because of chest pain. In 25 subjects with normal coronary angiograms (control group), AN inhalation increased the ejection time (ET), shortened the preejection period (PEP) and increased the ET/PEP markedly. In the 52 patients with CAD (CAD group), the ET/PEP changed insignificantly after AN. The difference between the 2 groups was significant (p less than 0.001). At cardiac catheterization, the increase of left ventricular dP/dt after AN in the control group was significantly larger than that in the CAD group. Although a positive correlation between changes in ET/PEP with AN and ejection fraction at rest was noted in patients with 1-vessel CAD, no such correlation was noted in those with multivessel CAD. This suggests that factors in addition to pump function, such as the degree of CAD, influence the effect of AN inhalation on systolic time intervals. When an increase of less than 30% in ET/PEP occurs with AN inhalation, the presence of significant CAD can be detected with a sensitivity of 92%, a specificity of 84% and the predictive value of 92%. The AN inhalation test is safe and simple, and thus could serve as a stress test for evaluating the presence and severity of significant CAD.

Amyl Nitrite↗

PubMed1984

Development of the utricular macula in the mouse.

There have been many studies reporting on the development of the utricular macula using transmission electron microscopy. This study demonstrates the morphological development of the utricular macula in the mouse using scanning electron microscopy. Utricular maculae from CBA/CBA mice were studied from the 11.5th gestational day to 2 weeks after birth. Between the 11.5th and 12.5th gestational day there are numerous microvilli and a primary cilium on the surface of the otocyst. Sensory hairs appear on the 13.5th gestational day. The kinocilium and stereocilia are short and the latter of almost equal in length. The polarity of the kinocilium is first noticed after the 16.5th gestational day. The formation of otoconia starts on the 14.5th gestational day. They are shaped like a dumb-bell and are oval and columnar. Otoconia with a hexagonal form are recognized after the 16.5th gestational day.

Acoustic Maculae↗

PubMed1984

An experimental study on a function of the cupula. Effect of cupula removal on the ampullary nerve action potential.

We used a posterior semicircular canal that had been isolated from a frog. From the utricular side the ampulla was cut open at a position one third of the way along the long axis. The cupula was removed through this opening using a glass micropipette. The action potential from the posterior ampullary nerve was recorded before and after removal of the cupula. After removal, the action potential disappeared almost completely. When the cupula was put back on the crista, the action potential was restored. When the cupula was put back upside down, the action potential recovered, but to a lesser extent.

Acoustic Stimulation↗

PubMed1984

Enhanced prostacyclin generation by phenolic compounds acting as a tryptophan-like cofactor of PG hydroperoxidase.

Isolated rat aortae were incubated at 22 degrees C in tris-buffered saline (pH 7.4). The incubation medium was changed every 10 min, and the amounts of prostacyclin (PGI2) in the medium were immediately bioassayed as an inhibitory activity against rabbit platelet aggregation induced by ADP. The addition of arachidonic acid to the medium increased the generation of PGI2 but this was followed by a gradual decrease even in the presence of the same amount of arachidonic acid. The decrease of PGI2 generation from exogenous arachidonic acid was prevented by tryptophan, which is required by PG hydroperoxidase with heme compound as cofactors. MK-447 and its analogues, which are phenolic compounds and exerted tryptophan-like action on the PG endoperoxide biosynthesis by bovine seminal vesicle microsomes, also prevented the decrease of PGI2 generation in isolated rat aortae. The phenolic compounds enhanced PGI2 generation from endogenous arachidonic acid. These results indicate that the phenolic compounds enhanced PGI2 generation in vascular tissue, acting as a tryptophan-like cofactor of PG hydroperoxidase.

Animals↗

PubMed1984

Rhabdomyosarcoma of the maxillary sinus. A case report.

A rare case of adult rhabdomyosarcoma originating from the left maxillary sinus is reported. A 22-year-old Japanese woman was referred to the Department of Otolaryngology, Hiroshima University, for investigation of the primary source of a metastatic tumor in the bone marrow. An X-ray of the sinuses revealed a tumor in the left maxillary sinus with extension into the nasal cavity, ethmoidal and sphenoidal sinuses. The patient was managed with a chemotherapeutic regimen consisting of high-dose methotrexate, adriamycin, vincristine, cyclophosphamide and prednisolone. After three courses of this chemotherapy, the tumor had decreased in size by about 90 per cent, as indicated by X-rays. The remaining tumor was removed by an extended Denker's operation. Following the surgery another seven courses of chemotherapy were given and during the eight months following the operation the patient has been free from any local recurrence.

Adult↗

PubMed1984

Cytogenetic and functional studies of leukocytes with Pelger-Huët anomaly.

A cytogenetic study was undertaken in 15 cases of Pelger-Huët (P-H) anomaly in 3 families. An enlarged short arm of chromosome 22 (22p+) was found in 14 cases, but in these families 4 cases without P-H anomaly did not show 22p+ in the karyotype. In P-H anomaly, delayed skin hypersensitivity reactions, levels of serum IgG, IgM and IgA, lymphocyte subpopulations, and natural killer and antibody-dependent, cell-mediated cytotoxicity activities were within normal range. The level of serum IgE, mitogen responses in peripheral blood lymphocyte and plaque-forming cell counts were also within normal range with the exception of a case with atopic eczema. Enzymatic activities, nitroblue tetrazolium reduction and phagocytic capacities of neutrophils appeared normal. Abnormalities of neutrophils in cases of P-H anomaly, as compared with normal subjects, were also negative in examinations for chemotaxis and spontaneous migration under agarose and in a membrane filter.

Adolescent↗

PubMed1984

Unstable angina in a patient with mucocutaneous lymph node syndrome.

An 11-year-old boy with mucocutaneous lymph node syndrome, who later developed an acute anteroseptal infarction and unstable angina, is presented. Anginal attacks were shown by 24-hour long-term ambulatory electrocardiographic recording. He was shown to have multiple coronary aneurysms with thrombi, and underwent a successful aorto-coronary bypass.

Aneurysm↗

PubMed1984

Action potential of isolated frog utricle.

The action potential of an isolated frog utricle was recorded using a suction electrode. The utricle was stimulated with iron sand which were spread evenly on the macula. A magnetic force was employed to induce the iron sand to depress the macula lightly. Integration of the action potential resulted in a phasic component, just as observed in the isolated semicircular canal potential (Harada et al., 1969). The amplitude of the utricular phasic component was liner to the logarithm of the stimulus intensity. Similar relationship was observed between the semicircular canal action potential and the stimulus (Harada & Hirata, 1981). Phasic on-response was invariably accompanied by an off-response. This suggests functional polarization of the utricle. It is already known that the macula is divided by the striola into two hair-cell groups having differing polarity. Since iron sand is spread evenly on the macula, all sensory cilia bend in one direction at the onset of the stimulus and one of the two cell groups evokes an on-response. At termination of the stimulus, sensory cells with the opposite polarity are stimulated, thus producing an off-response.

Action Potentials↗