Rapid quasi-periodic oscillations in the relativistic jet of BL Lacertae.

Blazars are active galactic nuclei (AGN) with relativistic jets whose non-thermal radiation is extremely variable on various timescales1-3. This variability seems mostly random, although some quasi-periodic oscillations (QPOs), implying systematic processes, have been reported in blazars and other AGN. QPOs with timescales of days or hours are especially rare4 in AGN and their nature is highly debated, explained by emitting plasma moving helically inside the jet5, plasma instabilities6,7 or orbital motion in an accretion disc7,8. Here we report results of intense optical and γ-ray flux monitoring of BL Lacertae (BL Lac) during a dramatic outburst in 2020 (ref. 9). BL Lac, the prototype of a subclass of blazars10, is powered by a 1.7 × 108 MSun (ref. 11) black hole in an elliptical galaxy (distance = 313 megaparsecs (ref. 12)). Our observations show QPOs of optical flux and linear polarization, and γ-ray flux, with cycles as short as approximately 13 h during the highest state of the outburst. The QPO properties match the expectations of current-driven kink instabilities6 near a recollimation shock about 5 parsecs (pc) from the black hole in the wake of an apparent superluminal feature moving down the jet. Such a kink is apparent in a microwave Very Long Baseline Array (VLBA) image.

Pregnancy achieved following IVF-ET after surgery for infertility with perforate transverse vaginal septum and incomplete septate uterus: case report.

Transverse vaginal septum is a rare congenital anomaly. Imperforate transverse vaginal septum causes marked clinical symptoms, and is diagnosed at a young age in most cases. Perforate transverse vaginal septum is difficult to detect due to the absence of symptoms. In this study, we report a case of a 33-year-old infertile female with a perforate transverse vaginal septum and incomplete septate uterus who had wished to bear a child for over ten years, and consulted our hospital. Transverse vaginal septum was considered to be an etiological factor for infertility. After surgery for transverse vaginal septum, in vitro fertilization achieved pregnancy.

Efficacy of two-route chemotherapy using cis-diamminedichloroplatinum(II) and its antidote, sodium thiosulfate, in combination with angiotensin II in a rat limb tumor.

We combined the angiotensin II (AT-II)-induced hypertension method with "two-route chemotherapy" (TRC), using cis-diamminedichloroplatinum(II) (CDDP) and its antidote, sodium thiosulfate (STS). The efficacy of the modified TRC was evaluated in rats bearing a limb tumor (transitional cell carcinoma). Immediately after infusing CDDP (15 mg/kg) and AT-II (15 micrograms/kg) via the femoral artery for 5 min, 1580 mg/kg STS (200-fold molar ratio to 15 mg/kg of CDDP) were administered i.v. for a further 5 min. Other treatments were as follows: 5 mg/kg of CDDP mixed or not mixed with 15 micrograms/kg of AT-II were given intraarterially (i.a.); 5 mg/kg of CDDP alone were injected i.v.; CDDP (15 mg/kg, i.a.) and STS (1580 mg/kg, i.v.) were simultaneously administered, without AT-II (conventional TRC). The antitumor effects of the modified TRC, evaluated by regression of tumor growth and extended life span, were superior to the other treatments. On the other hand, nephrotoxicity, loss of body weight, and leukopenia, seen in the rats given TRC with AT-II, occurred less than or at the same rate as in rats given other treatments. Thus, the TRC with AT-II was the most effective treatment given to rats bearing a regionally confined tumor. The feasibility of clinical application of modified TRC using i.a. CDDP plus AT-II and i.v. STS is discussed.

Increased therapeutic efficacy of intra-arterial carboquone chemotherapy on a limb tumor in rats, by using an acidic vehicle adjusted with lactate.

We previously reported that the cytotoxicity of carboquone (CQ) was potentiated in vitro and in vivo under acidic conditions. In this study, an acidic vehicle adjusted with lactate at various low pHs was used for CQ intra-arterial (i.a.) injection, in order to enhance the antitumor effects of i.a. CQ chemotherapy. Treatments were evaluated in Wistar/KA rats bearing a limb tumor 5 days after the inoculation of 3 x 10(6) syngeneic RBT-1 tumor cells into the hind limb. In chemotherapy experiments using an intrafemoral injection of CQ at 1.5 mg/kg in phosphate-buffered saline (PBS, pH 7.4) or in an acidic vehicle at pH 5.0 or 6.0, the antitumor effects seen in rats given CQ in acidic vehicles, evaluated by tumor weight 14 days after treatment, were significantly greater than that seen in rats given CQ in PBS. There were no significant differences either in changes of body weight or in the number of leukocytes after treatment between the groups given CQ in PBS and in an acidic vehicle at pH 6.0. Although in the group given CQ at 2.0 mg/kg in PBS, the antitumor effect was the same as that observed in rats given CQ at 1.5 mg/kg in an acidic vehicle at pH 6.0, the side effects observed in the former group were much severer than in the latter group. These data suggest that the antitumor effect of i.a. CQ chemotherapy can be potentiated by using an acidic vehicle.

Spectroscopic investigation of tertiary fold of staphylococcal protein A to explore its engineering application.

Staphylococcal protein A is a cell wall constituent of most strains of Staphylococcus aureus, and it is characterized by its binding affinity to some immunological classes. A mutated low molecular weight type protein A (LPA; Mwt = 27 kDa) which consists of the domains, E, D, A, B and 13 residues of the C-domain was prepared in this study. Since LPA does not possess a cell wall-bound region in contrast to wild-type protein A (WPA; Mwt = 42 kDa), we have established a methodology of large scale purification of LPA without using any extracellular expression systems such as Escherichia coli. Using this relatively abundant protein, the immobilization of the LPA with silk fibroin of Bombyx mori was performed. Thermal stability of LPA immobilized with silk fibroin is higher than that of free LPA at high temperature judging from the immunoglobulin G (IgG)-binding affinity. However, the apparent value of its affinity decreased relative to that of immobilized WPA. These results indicate that structural information is essential to explore improvement of IgG-binding affinity of immobilized LPA. Therefore, secondary structure of free LPA was detected by its characteristic helical pattern in circular dichroism (CD) in aqueous solution. In addition to this, tertiary fold of four IgG-binding domains were investigated by two-dimensional 1H-NMR spectra. Four significantly high-field shifted cross-peaks attributed to methyl signals of alanine residues suggest that all four domains pack into a three helix bundle motif in solution. These structural data and properties of IgG-binding affinity suggest that spatial arrangement of four IgG-binding domains are packed into a compact globular molecular shape. This causes a certain active site of immobilized LPA to be buried in the silk fibroin fiber.

The effect of dietary polyunsaturated fatty acid on insulin sensitivity and lipid metabolism in Otsuka Long-Evans Tokushima Fatty (OLETF) rats.

The effects of insulin sensitivity and lipid metabolism of dietary lard, eicosapentaenoic acid-rich oil (EPA oil) or arachidonic acid oil (AA oil) in Otsuka Long-Evans Tokushima Fatty (OLETF) rats were examined. Blood glucose was not different in each group at 30, 60, 120 min on an oral glucose tolerance test. Fasting blood glucose levels were lower in lard and AA oil groups than in controls. Hepatic triglyceride concentration and liver histochemistry revealed that the fat content was higher in the lard group and the AA oil group than in controls. The EPA oil group showed TG levels as high as the control group. Serum total cholesterol in the EPA oil group was lower, while the level in the AA oil group was higher than in the lard and control groups. HDL cholesterol was 1.5-fold higher in the AA oil group than in controls. Dietary EPA oil or AA oil supplementation showed different effects on lipid metabolism in this model.

Increased therapeutic effect on metastatic liver tumors in rats of two-route chemotherapy using cis-diamminedichloroplatinum (II) and its antidote, sodium thiosulfate, with temporary clamping of the abdominal aorta.

To improve the therapeutic effects of conventional "two-route chemotherapy" (TRC) comprising cis-diamminedichloroplatinum(II) (CDDP) given via the hepatic artery plus simultaneous i.v. sodium thiosulfate (STS) on metastatic liver tumors in rats, we combined TRC with aortic clamping at the supraceliac level. Treatments were evaluated in Wistar-King-Aptekman (WKA) rats bearing metastatic liver tumors 7 days after the inoculation of 10(6) syngenic RBT-1 (transitional-cell carcinoma) cells via the mesenteric vein. When 15 mg/kg CDDP was injected i.a. over 5 min, immediately followed by STS 1,580 mg/kg (200-fold the molar equivalent of 15 mg/kg CDDP) given i.v. over a further 5 min, the antitumor activity, evaluated by the number of tumor nodules present 12 days after treatment, was superior to that of conventional TRC (15 mg/kg i.a. CDDP plus simultaneous administration of 1,580 mg/kg i.v. STS), but the blood urea nitrogen (BUN) level was highly elevated (63.6 mg/dl). With aortic clamping for 7.5 min during CDDP administration and the first half of STS treatment, the TRC consisting of CDDP plus delayed STS (modified TRC) exhibited a further improvement in antitumor activity, with no nephrotoxicity (BUN, 17.1 mg/dl). Although the antitumor activity of 3 or 5 mg/kg i.a. CDDP was also increased by aortic clamping, in animals with normal BUN levels the survival of those treated with modified TRC was greater than that of rodents given 3 mg/kg i.a. CDDP with aortic clamping; however, the former was the same as that of animals given 5 mg/kg i.a. CDDP with aortic clamping whose BUN levels were elevated (31.2 mg/dl). Loss of body weight, the decrease in WBC counts, and changes in the serum transaminase levels in rats given modified TRC were tolerable. The improved therapeutic effect of modified TRC can be explained as follows: during aortic clamping, (a) CDDP delivery to the kidney decreased by 96% and made feasible the delay in STS administration after CDDP without nephrotoxicity, and (b) CDDP retention in the liver was increased by 366%, as aortic clamping decreased the portal blood flow, thereby inhibiting the washout of CDDP from the liver.

"Two-route chemotherapy" using cis-diamminedichloroplatinum(II) and its antidote, sodium thiosulfate, combined with angiotensin II is effective against peritoneally disseminated cancer in rats.

"Two-route chemotherapy" (TRC) using cis-diamminedichloroplatinum(II) (DDP) and its antidote, sodium thiosulfate (STS), combined with the angiotensin II (AT-II)-induced hypertension method was evaluated for its efficacy against peritoneally disseminated tumors in rats. A bolus i.p. injection of DDP (15 mg/kg) was given 1 min after the initiation of an AT-II (16.5 micrograms/kg) i.v. infusion lasting 11 min. Immediately after the termination of the AT-II infusion, 1,580 mg/kg STS was injected i.v. over a further 5 min. This modified TRC significantly improved the antitumor effect, evaluated by survival (increase in life span, 273%), compared with that achieved with other treatments, as follows: 15 mg/kg DDP i.p. and the concomitant i.v. infusion of 1,580 mg/kg STS (conventional TRC), 153% increase in life span; 5 mg/kg DDP i.p. with or without AT-II i.v. (167% and 107% increases in life span, respectively). As an index of nephrotoxicity, blood urea nitrogen (BUN) levels seen after modified TRC (21.1 mg/dl) were as low as those observed after conventional TRC (19.1 mg/dl), despite the postadministration of STS, and were much lower than those seen after DDP alone or DDP plus AT-II (35.6 and 35.7 mg/dl, respectively). Further evaluation of the effectiveness of modified TRC using various doses of DDP gave similar results. The feasibility of the administration of STS 10 min after DDP treatment was explained by the significant inhibition of DDP delivery to the kidney during the AT-II-induced hypertension. Thus, TRC combined with AT-II has a superior therapeutic effect against peritonitis carcinomatosa induced in rats.

Antitumor activity of nigericin and 5-(N-ethyl-N-isopropyl)amiloride: an approach to therapy based on cellular acidification and the inhibition of regulation of intracellular pH.

The extracellular pH (pHe) in solid tumors is frequently lower than the pHe in normal tissues, but the intracellular pH (pHi) is regulated to physiological levels. Cell killing can be achieved in an acidic environment in tissue culture by nigericin, which acidifies cells by transporting H+ from the extracellular space into the cytoplasm; this cell killing can be enhanced when used with 5-(N-ethyl-N-isopropyl)amiloride (EIPA), a potent inhibitor of membrane-based Na+/H+ exchange, which plays a major role in the regulation of pHi (R. P. Maidorn; E. J. Cragoe; I. F. Tannock, Br. J. Cancer 67:297-303; 1993). We have therefore assessed the ability of nigericin and EIPA to kill cells in two murine solid tumors (the KHT fibrosarcoma and the EMT-6 sarcoma). Hydralazine, which reduces tumor blood flow, or glucose, which stimulates glycolysis leading to accumulation of lactate, were also administered to mice to lower pHe in the tumors. We observed only a small decrease in the surviving fractions of cells in the tumors when tolerated doses of nigericin and EIPA were given IP to tumor-bearing mice. When nigericin and EIPA were combined with administration of hydralazine, the surviving fraction of cells in both tumors was reduced by a factor of 0.01, but there were minimal effects on growth delay. Administration of glucose with nigericin and EIPA led to a smaller reduction in surviving fraction of the KHT tumor (by approximately 0.1), although glucose was more effective than hydralazine in lowering the mean tumor pHe. When KHT tumors were treated with 15 Gy X-rays followed immediately by nigericin, EIPA, and hydralazine, a reduced surviving fraction as well as an increase in tumor growth delay was observed compared to radiation alone; however, there was little evidence to suggest that these agents were selectively toxic to the cells that survived radiation. Nigericin and EIPA, with or without hydralazine, had minimal effects on normal tissues, as assessed by changes in body weight, number of leukocytes, and serum creatinine levels. We conclude that pharmacological effects to acidify cells and to prevent regulation of pHi under the acidic conditions that exist in solid tumors can lead to moderate levels of cell killing, if additional strategies are used to lower tumor pHe.

An advantage for use of isotope labeling and NMR chemical shifts to analyze the structure of four homologous IgG-binding domains of staphylococcal protein A.

Because of the complexity arising from the large molecular size and the amino acid sequence homologies of IgG-binding domains of Staphylococcal Protein A (SpA), we have introduced, a combination of stable isotope labeling and both qualitative and quantitative investigations of the structural dependence of the NMR chemical shifts for its structure analysis. In order to enable selective isotope labeling with high efficiency, a mutated low molecular weight Protein A (LPA; MWt = 27 kDa) which consists of E, D, A, B and 13 residues of the C-domain was used in this study. Amide proton chemical shifts, measured using uniformly 15N-labeled LPA and LPA labeled selectively with 15N-alanine, show that the turn between helices 1 and 2, and its tertiary interactions with helix 3, are very similar in all domains. This contradicts previous results obtained using independent structure calculations on isolated domains. The close similarity in NH and 15N chemical shifts of alanine residues in the interdomain linker suggests that the linker maintains a similar structure both in isolated domains and in the intact protein. We show that the high-field shifted methyl signal of Ala 48 is affected by the ring-current effect arising from Phe 30, and has a very similar helical environment in all four domains. Thus, helix 3 is present in all domains, as we previously reported [Kikuchi et al., J Biochem Biophys Method, 1999:38:203-208], even though it is not observed in the crystal structure [Deisenhofer J. Biochemistry 1981;20:2361-2370].

YS-822A, a new polyene macrolide antibiotic. I. Production, isolation, characterization and biological properties.

A new polyene macrolide antibiotic, YS-822A was isolated from the culture filtrate of a mutant strain H-8 of Streptoverticillium eurocidicum var. asterocidicus S-822. Whereas the original S-822 strain produced not only YS-822 substances but also teleocidin as by-product which is well-known as a strong carcinogenic promoter, the mutagenized H-8 strain produced the antibiotic with only a trace amount of teleocidin. Chemical and biological characterizations of the antibiotic revealed that YS-822A (molecular formula: C37H59NO14) is a new polyene macrolide with a wide antifungal spectrum and a low acute toxicity.

YS-822A, a new polyene macrolide antibiotic. II. Planar structure of YS-822A.

The planar structure of a new polyene macrolide antibiotic, YS-822A, which was isolated from the culture filtrate of a mutant strain H-8 of Streptoverticillium eurocidicum var. asterocidicus S-822, was established as I on the basis of spectroscopic evidences and by comparison spectroscopic data with nystatin A1 (II) and amphotericin A (III), representative polyene macrolide antibiotics. Molecular formula of YS-822A was established as C37H59NO14 (MW 741) by elemental analysis, NMR, and FAB mass spectra. The UV spectrum of YS-822A was very similar to that of nystatin A1, suggesting that YS-822A also has a conjugated all-trans-tetraene moiety. 1H and 13C NMR spectra of YS-822A showed a number of broad and overlapped signals, but the 1H-1H and 13C-1H COSY spectra implied the existence of a mycosamine moiety and several other partial structures. The connectivity of these partial structures was established by extensive 2D NMR experiments, including homonuclear Hartmann-Hahn and heteronuclear multiple-bond connectivity measurements, which led to the determination of the gross planar structure of YS-822A as I.

Protein characterizations and immunological properties of the low-molecular-mass protein A isolated from Staphylococcus aureus KS 1034.

The extracellular low-molecular-mass protein A isolated from Staphylococcus aureus KS 1034 was analyzed for its amino acid contents and terminal amino acid sequences. The C-terminal and the N-terminal amino acid sequences of the low-molecular-mass protein A were -Asn-Ala-Phe and Ala-Gln-His-Asp-Glu-Ala-Gln-, respectively. For immunochemical properties, the low-molecular-mass protein A was similar to protein A isolated from S. aureus Cowan I. Extracellular protease activity of KS 1034 strain was considerably lower than S. aureus C-30 isolated from chicken that produced the extracellular low-molecular-mass protein A.

A novel therapy for internal hemorrhoids: ligation of the hemorrhoidal artery with a newly devised instrument (Moricorn) in conjunction with a Doppler flowmeter.

OBJECTIVES: To assess the usefulness of hemorrhoidal artery ligation (HAL) for internal hemorrhoids with a newly devised instrument (the Moricorn). METHODS: We devised a new instrument (the Moricorn) that is used in conjunction with a Doppler flowmeter. This instrument allows for easy and safe ligation of the hemorrhoidal artery. HAL with the Moricorn was performed on 116 patients with internal hemorrhoids who had episodes of anal pain, bleeding, and prolapse. One month after treatment, the effect was evaluated on the basis of improvement of symptoms and the shrinkage of hemorrhoidal tissue. RESULTS: The treatment's effect was observed in 50 of 52 patients (96%) with pain, 50 of 64 (78%) with prolapse, and 92 of 96 (95%) with bleeding. No patient required anesthesia throughout the entire procedure. No major complications were encountered with this treatment. CONCLUSIONS: HAL with the Moricorn is a simple, safe, and effective method. However, further observations predicated on a longer follow-up, a larger number of patients, and comparisons with other conventional treatments are called for.

Gentic properties of an R factor carrying resistance to aminolgycoside antibiotics.

R factor Rms 151 is an fi+ R factor and belongs to a incompatibility group FII. It carries the genes governing resistance to various aminoglycoside antibiotics, i.e., kanamycin (KM), lividomycin (LV), gentamicin C complex (GM), and 3',4'-dideoxykanamycin B (DKB), in addition to those governing to tetracycline (TC), chloramphenicol (CM), sulfanilamide (SA), and ampicillin (APC). Electron microscopy observation disclosed that the Rms151 deoxyribonucleic acid was a circular form with length of 31.2 mum. A probable circular genetic map of Rms151 was proposed by genetic and biochemical studies, the genes being in the order of -tet-tra-amp-aad-sul-aph-cml-, in which aad and aph confer resistance to KM.GM.DKB by adenylytransferase or resistance to KM.LV by phosphotransferase, respectively.