Misincorporation of dAMP opposite 2-hydroxyadenine, an oxidative form of adenine

Nucleotide incorporation opposite an oxidative form of adenine, 2-hydroxyadenine (2-OH-Ade) was investigated. When a primed template with 2-OH-Ade was treated with an exonuclease-deficient Klenow fragment of Escherichia coli DNA polymerase I (KFexo-), recombinant rat DNA polymerase beta (pol beta) or calf thymus DNA polymerase alpha (pol alpha), incorporation of dTMP and dAMP was observed. In addition, KFexo- inserted dGMP as well. A steady-state kinetic study indicated that the insertion of dAMP and dTMP opposite the DNA lesion occurred with similar frequency with KFexo- and pol beta. Insertion of dTMP opposite 2-OH-Ade was favored to that of dAMP by pol alpha. Chain extension from the A.2-OH-Ade pair is less favored than that from the T.2-OH-Ade pair by all three DNA polymerase. Analysis of full-length products of in vitro DNA synthesis showed that dTMP and dAMP were incorporated by DNA polymerases and that exonuclease-proficient and -deficient Klenow fragments also inserted dGMP opposite 2-OH-Ade. These results suggest that formation of 2-OH-Ade from A in DNA will induce A-->T and A-->C transversions in cells.

Surfactant protein-B supplementation improves in vivo function of a modified natural surfactant

The effect of the addition of surfactant protein (SP)-B or SP-B plus SP-C (SP-BC) to a surfactant made from bovine lung (Survanta) was evaluated in 27-d-gestation preterm rabbits. The animals were treated with Survanta, Survanta + 2% SP-B, Survanta + 3% SP-BC, or sheep surfactant. They were then ventilated with 3 cm H2O positive end-expiratory pressure and tidal volumes of 8 mL/kg. Survanta + 2% SP-B was prepared by adding SP-B in water to Survanta or by adding SP-B in chloroform [SP-B(Chl)] to lipid-extracted Survanta. Dynamic compliances of the Survanta + 2% SP-B(Chl)- and Survanta + 3% SP-BC-treated rabbits were greater (p < 0.05) than those treated with Survanta or Survanta + 2% SP-B in water and were comparable to sheep surfactant. Postventilation pressure-volume curves for the groups treated with Survanta supplemented with SP-B had significantly larger retained volumes on deflation compared with those treated only with Survanta (p < 0.01). The effects of ventilation style on the responses were assessed by ventilating other groups of rabbits treated with Survanta, Survanta + 0.5% SP-B(Chl), Survanta + 2% SP-B(Chl), or sheep surfactant with tidal volumes of 10 mL/kg and 0 cm H2O positive end-expiratory pressure. SP-B (2%) augmented the in vivo function of Survanta without positive end-expiratory pressure, and 0.5% SP-B had no effect. Infasurf, a surfactant with more SP-B, was more effective than Survanta when tested in the preterm rabbits. SP-B is a critical factor for optimum immediate surfactant function.

Exogenous surfactant function in very preterm lambs with and without fetal corticosteroid treatment

We have asked whether the function of a bovine source surfactant frequently used clinically (Survanta) could be enhanced after exposure to the very preterm lung when the surfactant was subsequently tested in vivo in preterm surfactant-deficient rabbits. We also evaluated whether there would be effects resulting from fetal treatment with 0.5 mg/kg betamethasone given 48 h before delivery of lambs at 121 days gestational age. The fetal corticosteroid treatment significantly improved gas exchange, increased compliance, increased functional residual capacity, decreased vascular-to-alveolar protein leak, and increased static lung volumes. However, surfactant from both groups of lambs, recovered by alveolar wash and subsequently fractionated to recover the large-aggregate functional surfactant, was equivalent in function to the Survants given to the lambs when tested in preterm surfactant-deficient rabbits. Addition of plasma to Survanta resulted in high minimum surface tensions in vitro, and this inhibition could be prevented by supplementation of the Survanta with 5 or 10% sheep surfactant. No activation occurred with treatment of the very preterm lung, a result consistent with the lung being too immature to contribute components to the surfactant used for treatment. Fetal corticosteroid treatment had no effect on surfactant function at this gestational age.

Absolute stereostructures of hovenidulciosides A1 and A2, bioactive novel triterpene glycosides from hoveniae semen seu fructus, the seeds and fruit of Hovenia dulcis Thunb

Two bioactive novel triterpene glycosides named hovenidulciosides A1 and A2 have been isolated from a Chinese natural medicine, Hoveniae Semen Seu Fructus, the seeds and fruit of Hovenia dulcis Thunb. (Rhamnaceae). The absolute stereostructures of hovenidulciosides A1 and A2 with a migrated 16,17-seco-dammarane skeleton have been determined on the basis of chemical and physicochemical evidence which included the X-ray crystallographic analysis of the p-bromobenzoate of their common aglycone, hovenidulcigenin A. Hovenidulciosides A1 and A2 exhibited inhibitory activity on the histamine release from rat mast cells induced by compound 48/80 or calcium ionophore A-23187.

Genetic diversity of N2-fixing bacteria associated with rice roots by molecular evolutionary analysis of a nifD library

The rhizosphere of wetland rice has significant N2-fixing activity. It has been suggested that N2 fixation in the rice root zone is associated with the activity of various N2-fixing heterotrophic bacteria that inhabit the rice rhizosphere. Because of the generic diversity, many different isolation media and conditions are required to count and isolate these bacteria. In an attempt to overcome any bias from culture-dependent methods we amplified nifD segments from crude rice root DNA by the polymerase chain reaction. The nifD fragments were then cloned into a pT7 Blue T-vector to construct a nifD library. Sixteen cloned nifD genes chosen at random from the library were sequenced. A comparison with published sequences indicated the presence of seven novel groups of NifD proteins, which implies the existence of at least seven components in the diazotrophic community of rice roots, dominated mainly by proteobacteria. We also observed genetic variability within the clusters, which suggests the coexistence of many closely related bacterial lineages. However, we did not find Azospirillum-like nifD clones, although many reports indicated the widespread presence of Azospirillum spp. Therefore, it remains to be clarified whether Azospirillum species are the widespread N2-fixing bacteria in rice roots.

Clinical usefulness of evaluation of portal circulation by per rectal portal scintigraphy with technetium-99m pertechnetate

OBJECTIVE

Portal circulation, in particular the contribution of the inferior mesenteric vein, can be evaluated in a relatively noninvasive way by per rectal portal scintigraphy (J Nucl Med 1988; 29:460-5). The clinical usefulness of the method was evaluated.

METHODS

A solution containing technitium-99m pertechnetate was instilled into the rectum, and serial scintigrams were taken while radioactivity curves for the liver and heart were recorded sequentially. By analyses of the curves, the per rectal portal shunt index (SI) was calculated.

RESULTS

The SI was higher for disorders that were more severe, increasing in the order of chronic persistent hepatitis, chronic aggressive hepatitis, and cirrhosis, and the SI was higher in cirrhotic patients than in patients with chronic hepatitis or in healthy subjects. The SI was significantly higher when a complication (varices, ascites, or encephalopathy) was present. Correlation between the SI and classic indicators for functional reserve was significant. The SI was significantly related to survival according to results of regression analysis by Cox's proportional hazards model. On the basis of the SI when patients were first examined, the patients with cirrhosis were divided into three groups of roughly equal size: group A, SI under 30%; group B, SI between 30 and 70%; and group C, SI over 70%. The survival rate was lower in group B than in A, lower in group C than in A, and lower in group C than in B.

CONCLUSIONS

This method is clinically useful, especially in establishing the prognosis.

Adsorption-desorption of proteins on phospholipid polymer surfaces evaluated by dynamic contact angle measurement

Adsorption-desorption of plasma protein on various polymer membranes was evaluated by a dynamic contact angle (DCA) measurement using the Wilhelmy plate method. Poly(ethylene terephthalate) (PET) was used as a substrate membrane; we examined this membrane coated with hydrophilic polymers such as poly[2-methacryloyloxethyl phosphorylcholine (MPC)-co-n-butyl methacrylate (BMA)] or poly[2-hydroxyethyl methacrylate (HEMA)]. Although the zeta-potential of the PET membrane was negative, the coating with poly(MPC-co-BMA) induced increase of value to nearly zero. The DCA loops observed on the polymer membranes after protein adsorption were unity and hysteresis of the loop was reduced. In the cases of protein adsorbed on both the PET and the poly(HEMA) membranes, the shape and hysteresis of the loops were almost same during the rinsing process with a phosphate-buffered solution (PBS). However, the hysteresis of the DCA loops that appeared on the protein-adsorbed poly(MPC-co-BMA) membrane became large during the rinsing process with the PBS, and the shape of the DCA loop returned to its non-protein-adsorbed state. Therefore, proteins adsorbed on poly(MPC-co-BMA) could desorb more readily than those on PET and poly(HEMA) because of the weak interaction between poly(MPC-co-BMA) and the proteins.

A new approach for performing a one-stage operation through the mediastinum to resect bilateral lung metastases: report of a case

We describe herein a new operative technique for reaching the opposite lung from the thoracotomy site through the mediastinum. This procedure was successfully performed on a 76-year-old woman with bilateral lung metastases whose case is presented. After resection of the right lower lobe which contained two metastases, the anterior mediastinum was opened, and contralateral metastasis located in the lingular segment was resected using a neodymium:yttrium-aluminum-garnet (Nd:YAG) laser. A chest drainage tube was inserted through the mediastinal window. This transmediastinal approach seems to be a feasible technique for preserving the respiratory function of the chest wall in patients with imbalanced bilateral metastases.

Polarized Raman spectra of oriented fibers of A DNA and B DNA: anisotropic and isotropic local Raman tensors of base and backbone vibrations

Polarized Raman spectra of oriented fibers of calf thymus DNA in the A and B conformations have been obtained by use of a Raman microscope operating in the 180 degrees back-scattering geometry. The following polarized Raman intensities in the spectral interval 200-1800 cm-1 were measured with both 514.5 and 488.0 nm laser excitations: (1) Icc, in which the incident and scattered light are polarized parallel to the DNA helical axis (c axis); (2) Ibb, in which the incident and scattered light are polarized perpendicular to c; and (3) Ibc and Icb, in which the incident and scattered light are polarized in mutually perpendicular directions. High degrees of structural homogeneity and unidirectional orientation were confirmed for both the A and B form fibers, as judged by comparison of the observed Raman markers and intensity anisotropies with measurements reported previously for oligonucleotide single crystals of known three-dimensional structures. The fiber Raman anisotropies have been combined with solution Raman depolarization ratios to evaluate the local tensors corresponding to key conformation-sensitive Raman bands of the DNA bases and sugar-phosphate backbone. The present study yields novel vibrational assignments for both A DNA and BDNA conformers and also confirms many previously proposed Raman vibrational assignments. Among the significant new findings are the demonstration of complex patterns of A form and B form indicator bands in the spectral intervals 750-900 and 1050-1100 cm-1, the identification of highly anisotropic tensors corresponding to vibrations of base, deoxyribose, and phosphate moieties, and the determination of relatively isotropic Raman tensors for the symmetrical stretching mode of phosphodioxy groups in A and B DNA. The present fiber results provide a basis for exploitation of polarized Raman spectroscopy to determine DNA helix orientation as well as to probe specific nucleotide residue orientations in nucleoproteins, viruses, and other complex biological assemblies.

Remarkable N2-fixing bacterial diversity detected in rice roots by molecular evolutionary analysis of nifH gene sequences

To demonstrate the extent of phylogenetic diversity of diazotrophic bacteria associated with rice roots, we characterized phylogenetically 23 nifH gene sequences obtained by PCR amplification of mixed organism DNA extracted directly from rice roots without culturing the organisms. The analyses document the presence of eight novel NifH types, which appear to be a variety of significant components of the diazotrophic community, dominated mainly by proteobacteria.

Changes in coagulation and fibrinolytic system after local intra-arterial thrombolysis for acute ischemic stroke

Intracerebral hemorrhagic transformation is one of the most important complications of thrombolytic therapy for acute ischemic stroke. The relationship between changes in markers for the coagulation and fibrinolytic systems and occurrence of hemorrhagic transformation was determined after local intra-arterial thrombolytic therapy using urokinase (UK) (24 patients) or recombinant tissue plasminogen activator (t-PA) (10 patients) within 6 hours of onset. All 34 patients had no hypodensity areas on initial computed tomography scans. Plasma concentrations of fibrinogen-fibrin degradation products (FDP), fibrinogen, alpha 2-plasmin inhibitor (alpha 2-PI), plasmin-alpha 2 plasmin inhibitor complex (PIC), thrombin-antithrombin III complex (TAT), and D-dimer were measured. Hemorrhagic transformation occurred in seven patients (21%) with complete or partial recanalization; four in the UK group and three in the t-PA group. Doses of the thrombolytic agents did not correlate with the incidence of hemorrhagic transformation. The FDP levels in the hemorrhagic transformation group treated with UK significantly increased immediately and 1 hour after the therapy. The alpha 2-PI activities decreased and PIC levels increased in both the hemorrhagic transformation and the nonhemorrhagic groups after the therapy. The TAT levels in both groups tended to be higher than the normal range, but there was no significant difference from the pretreatment levels. The D-dimer levels in the hemorrhagic transformation group were higher than those in the nonhemorrhagic group at 24 hours after the therapy. Furthermore, the D-dimer levels were significantly higher in patients with complete recanalization compared with those with none or partial recanalization.(ABSTRACT TRUNCATED AT 250 WORDS)

Phenotypic instability of transgenic tobacco plants and their progenies expressing Arabidopsis thaliana small GTP-binding protein genes

Chimeric genes consisting of the cauliflower mosaic virus 35S promoter, a cDNA encoding a small GTP-binding protein from Arabidopsis thaliana (ara-2 or ara-4) and the terminator of the nopaline synthase gene were cloned into a binary vector. Tobacco leaf tissues were transformed with this plasmid via Agrobacterium-mediated transformation. Transgenic plants possessing either ara-2 or ara-4 occasionally showed morphological abnormalities in leaves and other organs. However, such alterations were not always associated with co-transferred characters, such as kanamycin tolerance, and they arose in no more than 10% of the transgenic plants. Such phenomena were also observed in the progenies of the primary transgenic plants. Despite such unusual inheritance of the phenotypic abnormalities, GTP-binding activity of the inserted ara gene products was detected in all plants tested.

Mammalian tissue trypsin-like enzymes: substrate specificity and inhibitory potency of substituted isocoumarin mechanism-based inhibitors, benzamidine derivatives, and arginine fluoroalkyl ketone transition-state inhibitors

Amino acid and peptide thioesters which contained Arg or Lys in the P1 position were tested as substrates for rat skin tryptase, and the kinetic constants Kcat/KM for the better substrates such as Z-Aba-Arg-SBzl, and Z-Gly-Arg-SBzl were over 5,000,000 M-1 s-1. The inhibitory potency of arginine fluoroalkyl ketones, benzamidine derivatives, and substituted isocoumarins containing basic functional groups was studied with rat skin tryptase, human lung tryptase, human skin tryptase, and bovine trypsin. 1-Naphthoyl-Arg-CF3 was the best arginine fluoroalkyl ketone reversible inhibitor for rat skin tryptase with a KI of 0.9 microM. 1-(4-Amidino-phenyl)-3-(4-phenoxyphenyl) urea showed competitive inhibition against bovine trypsin and rat skin tryptase with KI values of 2 and 4 microM, respectively. Isocoumarin derivatives with isothioureidoalkoxy substituents at the 3 position were potent irreversible inhibitors of these three tryptases with Kobs/[I] values of 10(4)-10(5) M-1 s-1. 4-Chloro-3-(2-isothioureido)ethoxy-7-phenylcarbamoylaminoisocou marin and 7-benzylcarbamoylamino-4-chloro-3-(3-isothioureido)propox yisocoumarin inactivated trypsin and formed stable trypsin-inhibitor complexes which regained less than 8% of activity upon standing in the pH 7.5 buffer and regained 30-75% of activity in the presence of 0.3 M NH2OH after 1 day. In contrast, the complexes with rat skin tryptase regained activity rapidly, indicating differences in the inhibition mechanism and active site structures of these related enzymes.

Effective renaturation of reduced lysozyme by gentle removal of urea

To increase the folding yield of concentrated reduced lysozyme, we developed a renaturation method by means of dialysis from concentrated urea with redox agents. After lysozyme was incubated in the reducing buffer (8 M urea solution) with oxidized glutathione, renaturation of reduced lysozyme was started by dialysis against the dialyzing buffer containing 8 M urea with redox agents. The urea concentration of the dialyzing bottle was gradually diluted with dialyzing buffer without urea at a flow rate of 0.1 ml/min by high pressure pump. Using this systematic dialysis, a concentration as high as 5 mg/ml of reduced lysozyme could be renaturated in 80% yield, while the folding yield was < 5% even at a concentration of 1 mg/ml using a conventional rapid dilution method [Goldberg et al. (1991) Biochemistry, 30, 2790-2797]. Therefore, it was concluded that gentle removal of urea from denatured proteins, dissolved in concentrated urea solution, by means of dialysis should be useful to renature denatured proteins effectively.

[Effect of copper and copper binding protein on the CT attenuation value of liver: experimental study in rats]

We analyzed the effect of copper and copper binding protein on CT attenuation value in a rat model. CT attenuation values of the liver were compared with hepatic copper content and grade of orcein-positive granules, which are thought to be a counterpart of polymerized methalothionein in lysosomes. The difference between hepatic copper and CT attenuation value was not statistically significant (R = 0.056, p = 0.96). CT value had a positive correlation with the grade of orcein-positive granules (Rho = 0.755, p = 0.0001). We concluded that the CT attenuation value of liver can be elevated by rich polymerized methalothionein (copper binding protein) in lysosomes.

[Renal cell carcinoma in a patient with malignant lymphoma: a case report]

This is a case report of a 51-year-old male in the late stage of malignant lymphoma who presented with pathological fracture renal cell carcinoma secondary to metastatic. He underwent right nephrectomy followed by immunotherapy consisting of interferon alpha and some cytokines. According to his condition and extension of the disease, OK-432, interleukin-2 and interferon gamma were combined. He was also given irradiation to the bone metastases. He died of progressive disease 8 years and 6 months after the initiation of interferon alpha therapy. The autopsy revealed evidence of pancreatic involvement with renal cell carcinoma and malignant lymphoma as well. Malignant lymphoma also infiltrated into the mesentery and left femur. We reviewed other reports regarding multiple malignant tumors associated with renal cell carcinoma and discussed the occurrence of malignant lymphoma in renal cell carcinoma patients.

Evaluation of portal circulation through the superior mesenteric vein with an enteric capsule of [123I]iodoamphetamine

We report a method by which the contribution of the superior mesenteric vein to the portal blood flow can be evaluated noninvasively. An enteric-coated capsule containing [123I]iodoamphetamine is given by mouth 3h before the examination. The data obtained are treated by computer to calculate the portal shunt index (SI) through the superior mesenteric vein. The SI was higher for more severe liver disorders, Increasing in the order of chronic persistent hepatitis, chronic aggressive hepatitis, and cirrhosis. The SI was higher in cirrhotic patients than in chronic hepatitis patients or healthy volunteers (both, P < 0.0001). The SI was higher in cirrhotic patients with esophageal varices than in such patients without varices (P < 0.05). The SI was higher in cirrhotic patients with ascites than in such patients without ascites (P < 0.001). The SI was higher in cirrhotic patients with encephalopathy than in those without encephalopathy (P < 0.01). Correlation was significant between the SI and classical indicators of functional reserve. This method is clinically useful.

Phylogeny of Sym plasmids of rhizobia by PCR-based sequencing of a nodC segment

To understand the host specificity of rhizobia and the relationship between the evolution of Sym plasmids and that of host plants, we determined partial nodC sequences of 10 representative rhizobium strains and then constructed an evolutionary tree for the deduced amino acid sequences with four published sequences. These coding sequences yield a phylogenetic tree similar to that for leghemoglobin of host plants, suggesting that the evolution of common nodulation genes may be linked to host legume evolution and speciation.

Clearance of surfactant protein A from rabbit lungs

Surfactant protein A (SP-A) is a major surfactant protein with multiple biophysical, metabolic, and host defense functions. To further characterize its metabolism in vivo, we measured clearance of SP-A from adult rabbit lungs. Trace amounts of [125I]SP-A radiolabeled by the Bolton-Hunter method and mixed with [3H]dipalmitoylphosphatidylcholine (DPPC) were given intratracheally via a bronchoscope to rabbits. Groups of five to six animals were studied 10 min to 16 h after labeled surfactant administration. After collection of alveolar washes, lamellar bodies were isolated from lung tissue. Macrophages also were isolated from alveolar washes. [125I]SP-A was cleared more rapidly than DPPC from the airspaces. Both [125I]SP-A and [3H]DPPC were lost exponentially from the total lungs, with half-life values of 6.5 h for SP-A and 12 h for DPPC (P < 0.01). In macrophages, the highest radioactivities for SP-A and DPPC were at 10 to 45 min and the radiolabels subsequently disappeared similarly. In lamellar bodies, 125I and 3H radioactivities per mumol saturated phosphatidylcholine (Sat PC) increased in parallel and were highest at 2 h. Whereas radiolabeled lipids were recovered in lamellar bodies for up to 16 h, iodinated SP-A was lost, indicating less recycling of SP-A than DPPC. We previously showed independent pathways of SP-A and Sat PC secretion in rabbits. These results demonstrate the different clearance kinetics of these two principle components of surfactant.

The influence of unilateral vertebral artery occlusion on bilateral inner ear blood flow in rats

We investigated the influence of unilateral vertebral artery (VA) occlusion on bilateral inner ear blood flow in rats using laser Doppler flowmetry for the measurement of bilateral cochlear blood flow (CBF) and photochemically initiated thrombosis for VA occlusion. BP and CBF showed little change by unilateral VA occlusion alone. However, subsequent hypotension induced by venesection not only reduced CBF but also caused imbalance between bilateral CBF reduction rates. CBF changed independently of BP, indicating the existence of a local CBF regulatory system.

Clinical application of ultrasonic blood rheography for vertigo

The blood flow in the vertebral artery was measured in 507 patients with vertigo using ultrasonic blood rheography. In 150 of the 507 cases (32%), abnormal findings including laterality and decreased flow were detected. Twenty-one cases whose clinical course was observed showed a decrease in the differences in velocity between sides as vertigo improved. VBI (vertebro-basilar insufficiency) showed a worse prognosis in patients with laterality compared with those without and a positive correlation was demonstrated between side differences and fluctuating blood pressure or serum lipids. Some anti-vertiginous drugs improved the difference between sides by increasing the velocity.

Treatment of advanced hormone-refractory prostate carcinoma with a combination of etoposide, pirarubicin and cisplatin

A total of 20 patients with hormone-refractory prostate carcinoma entered a pilot study of combination chemotherapy based on the EAP (etoposide, Adriamycin and cisplatin) regimen, in which Adriamycin was replaced by pirarubicin, a less cardiotoxic derivative of Adriamycin. The response was assessed by criteria modified from those of the National Prostatic Cancer Project: prostate-specific antigen was employed instead of acid phosphatase. Of 18 evaluable patients, 6 achieved a partial response, 5 had stable disease, and in 7 the disease had progressed during therapy; thus, the overall response rate was 33.3% [95% confidence interval (CI) 11.5-55.1%]. Significant pain alleviation and performance status improvement were obtained in 5 of 12 patients (41.7%; CI 13.8-69.6%) and 3 of 13 patients (23.1%; CI 0.2-46.0%), respectively. Although myelosuppression was moderate to severe, no chemotherapy-related deaths or bacteriologically documented sepsis occurred; nor was there any clinical cardiotoxicity. All the responding patients received maintenance chemotherapy with etoposide thereafter. At present, the median duration of response is 33 weeks (range: 23-91 weeks) and the median survival period for all patients is 42 weeks (range: 27(+)-136 weeks), with 12 deaths. In spite of the small number of patients treated, these results suggest that this chemotherapy regimen is active in advanced hormone-refractory prostate carcinoma.

Comparative mapping of the imprinted U2afbpL gene on mouse chromosome 11 and human chromosome 5

The genetic map location of the recently discovered imprinted gene U2afbpL has been verified and refined in several mouse crosses. RI strain analysis had previously shown that the gene is located on mouse chromosome 11. This assignment has been verified using interspecific backcrosses. Moreover, the location of the gene relative to a fixed order of markers in the proximal region of mouse chromosome 11 has been established. The location of the gene on mouse chromosome 11 corresponds to a homologous linkage group that is conserved on human chromosome 5q. The location of the human homologue has been determined using both somatic cell hybrid genetic analysis and fluorescence in situ hybridization. These analyses have mapped the human locus U2AFBPL to human chromosome 5q23-->q31.