Explosive deep water basalt in the sumisu backarc rift.

Eruption of 1-million-year-old tholeiitic basalt >1800 meters below sea level (>18 megapascals) in a backarc rift behind the Bonin arc produced a scoriaceous breccia similar in some respects to that formed during subaerial eruptions. Explosion of the magma is thought to have produced frothy agglutinate which welded either on the sea floor or in a submarine eruption column. The resulting 135-meter-thick pyroclastic deposit has paleomagnetic inclinations that are random at a scale of <2.5 meters. High magmatic water content, which is about 1.3 percent by weight after vesiculation, contributed to the explosivity.

Radiolabeling of lectin from Robinia pseudoacacia by reductive methylation.

Lectin from the bark of Robinia pseudoacacia was radiolabeled by reductive methylation. Reductive methylation of the lectin with [14C]formaldehyde and a reducing agent, sodium borohydride, resulted in incorporation of 14C into the lectin but with considerable inactivation of carbohydrate binding activity. Dialysis of the labeled lectin against the buffer containing Ca2+ and Mn2+ partially restored the activity. Higher incorporation of 14C into the lectin was observed when sodium cyanoborohydride was used as a reducing agent. In this case, more than eighty percent of the labeled lectin retained carbohydrate binding activity. Autoradiography showed that the radiolabeled lectin had a molecular mass of 29 kDa, corresponding to that of the intact lectin subunit.

Studies by site-directed mutagenesis of the carbohydrate-binding properties of a bark lectin from Robinia pseudoacacia.

A bark lectin, RBL, from Robinia pseudoacacia (black locust), binds galactose-related sugars specifically. Recombinant RBL (rRBL) with a histidine tag was expressed in Escherichia coli, purified and characterized. rRBL agglutinated rabbit erythrocytes and the hemagglutination was inhibited by galactose and related sugars. To elucidate the mechanism of the binding of carbohydrate by RBL, 16 mutant rRBLs were produced by site-directed mutagenesis. The analysis of the mutants indicated that residues Phe130 and Asp87 play key roles in the binding of carbohydrate by RBL. When Thu215, Leu217 and Ser218 in the carboxy-terminal region were replaced by alanine, the respective replacements decreased the hemagglutinating activity. However, replacement by alanine of Glu219 did not decrease this activity. Three mutant rRBLs were generated by reference to the primary sequences of the proposed carbohydrate- and metal-binding regions of mannose-specific lectins. Although these rRBLs agglutinated rabbit erythrocytes, the hemagglutination was not inhibited by mannose. Substitution or insertion that yielded a partial sequence similar to those of L-fucose-specific lectins and hemagglutinin from Maackia amurensis resulted in a complete loss of the hemagglutinating activity of rRBL.

Expression of cDNA for a bark lectin of Robinia in transgenic tobacco plants.

A cDNA encoding a bark lectin of Robinia pseudoacacia was introduced into tobacco plants. The expression of the lectin cDNA under control of the 35S promoter was confirmed by Western blot analysis and a hemagglutination assay of extracts of transgenic plants. Western blot analysis revealed that the subunit of the lectin from tobacco had a molecular mass of 29 kDa. The sequence of nine amino acids from the N-terminus of the lectin from transgenic tobacco plants was identical to that of the bark lectin from Robinia, indicating that the lectin had been processed correctly at its N-terminus in tobacco. The molecular mass of the purified native lectin produced by tobacco plants was estimated to be 112 kDa by gel filtration on a column of Superdex 200. It is suggested that the lectin subunits assembled to form tetramers in transgenic tobacco plants.

A comparative study of bark lectins from three elderberry (Sambucus) species.

Three elderberry lectins isolated from the bark of three different species of the genus Sambucus which are native to Europe (S. nigra), North America (S. canadensis), and Japan (S. sieboldiana) were studied comparatively with regard to their carbohydrate binding properties and some structural features. All three lectins contained two identical carbohydrate binding sites per molecule and showed a very high specificity for the Neu5Ac(alpha 2-6)-Gal/GalNAc sequence. However, relative affinities for various oligosaccharides were significantly different among them, suggesting differences in the detailed structure of the carbohydrate binding sites of these lectins. The three lectins were immunologically related, but not identical, and all were composed of hydrophobic and hydrophilic subunit regions, although the molecular sizes of these subunits were slightly different among the three lectins. N-terminal sequence analysis of the subunits of these lectins suggested that they have a very similar structure in this region but also indicated the occurrence of N-terminal processing such as the deletion of several amino acid residues at the N-termini for both hydrophobic and hydrophilic subunits of all three lectins. Tryptic peptide mapping of the three lectins showed a similar pattern for all of them but also showed the presence of some unique peptides for each lectin.

Interaction of Porphyromonas gingivalis with transferrin.

In this study, we characterized the binding of transferrin to Porphyromonas gingivalis using a classical receptor-binding assay, and examined the relationship between the binding and availability of transferrin for the growth of P. gingivalis. The binding of 125I-labeled human transferrin to P. gingivalis occurred rapidly, reversibly and specifically. Scatchard analysis yielded a Kd of 1.37 +/- 0.16 microM and an apparent number of 1.13 +/- 0.26 x 10(5) receptors per cell. The binding of transferrin was much increased when organisms were grown in iron-limited conditions. Among the species of black-pigmented anaerobic.rods, those strains of P. gingivalis which had high transferrin-binding activity exhibited unrestricted growth following the addition of transferrin to the hemin-free culture medium. On the other hand, the presence of transferrin in the culture medium did not support unrestricted growth of organisms that had low transferrin-binding activity. These results suggest that the binding of transferrin to P. gingivalis cells may be a preliminary step in iron acquisition, which allows them to survive in the healthy periodontal environment.

Effect of concentration of compounds containing iron on the growth of Porphyromonas gingivalis.

We examined the effect of the concentration of various types of iron molecules on the regulation of growth of Porphyromonas gingivalis. Bacterial growth was monitored spectrophotometrically. The hemin-depleted cells of P. gingivalis 381 were incubated in the basal medium plus test substrates such as hemoglobin, hemin, transferrin and various inorganic iron compounds. The relationship between the specific growth rate of organisms and the concentration of iron-containing compounds was determined. The value of Ks, a parameter analogous to the Michaelis-Menten constant, was estimated. P. gingivalis 381 showed a Ks value of 3.85, 4.91 and 0.0017 microM for hemin, transferrin and hemoglobin, respectively. However, the inorganic iron compounds tested did not support growth of P. gingivalis. These findings suggest that P. gingivalis utilizes hemoglobin as an iron source much more effectively than other iron-containing compounds under an iron-limited environment.

Binding of hemoglobin by Porphyromonas gingivalis.

In this study, we investigated whether Porphyromonas gingivalis can bind hemoglobin as an initial step in the acquisition of heme from hemoglobin. The binding of human hemoglobin by P. gingivalis cells was determined using [3H]hemoglobin. Hemoglobin binding occurred rapidly, reversibly and specifically. A Scatchard analysis of the binding data generated a linear plot, indicating a single population of binding proteins. The apparent Kd was 1.0 +/- 0.19 x 10(-6) M and there were 3.2 +/- 0.76 x 10(4) binding sites per cell. Hemoglobin binding was inhibited by unlabeled human hemoglobin but not by hemin and protoporphyrin IX. The binding was only partially inhibited by human serum albumin, transferrin, lactoferrin, catalase and cytochrome c. These results suggest that the ligand recognized by the binding protein may not be the heme moiety. The binding of hemoglobin considerably increased when the organisms were grown under hemin-limited conditions. Hemoglobin bound to outer membrane proteins extracted from P. gingivalis cells on a dot blot binding assay and binding ability was lost after heating bacterial proteins. These results suggest that P. gingivalis cells interact with human hemoglobin through specific binding sites on their surfaces as a preliminary step in iron acquisition.

237Np in hemp-palm leaves of Bontenchiku for fishing gear used by the Fifth Fukuryu-Maru: 40 years after "Bravo".

The alpha radioactive components in the Hemp-palm of Bontenchiku were determined with emphasis on the measurement low-level 237Np by alpha-ray spectrometry after chemical separation. Bontenchiku is a kind of fishing gear for long-line fishing used by the Fifth Fukuryu-Maru (Lucky Dragon). This gear was exposed to fallout from the second thermonuclear test explosion (Bravo) at Bikini Atoll in March 1954. The 237Np content in the Bontenchiku sample was determined to be 11.5 +/- 0.8 mBq g(-1), with an activity ratio of 237Np:239,240Pu and an atom ratio of 237Np:239Pu estimated to be (2.2 +/- 0.2) x 10(-3) and 0.42 +/- 0.04, respectively. The data showed the existence of a chain reaction of 238U and its ratio to be 237Np:239Pu, as well as the presence of 237U at the time of fallout from Bravo event in March 1954.

[Treatment of whooping cough and whooping cough syndrome by cefoperazone (author's transl)].

Clinical trial of cefoperazone (CPZ) for the treatment of whooping cough and whooping cough syndrome was performed and the following results were obtained. 1) In 18 cases suffering from whooping cough, CPZ was given 47 approximately 106 mg/kg/day (average 72 mg/kg/day) by intravenous route. The clinical efficacy rates judged by doctors in charge were 44% on the 3 rd day, 75% on the 7 th day, 86% on the period day. And in these cases, the clinical efficacy rates judged by committee members were 56%, 83% and 86%. 2) In 6 cases diagnosed as whooping cough syndrome, CPZ was given 49 approximately 96 mg/kg/day (average 59 mg/kg/day) by the same route. The clinical efficacy rates judged by doctors in charge were 67% on the 3 rd day, 80% on the 7 th day and 75% on the period day. And in these cases, those judged by committee members were 83%, 80% and 100%. 3) In 1 case, Bordetella pertussis was searched and showed 0.012 mcg/ml of MIC. It was eliminated on the 1 st day after administration. 4) Doctors in charge judged the utility of CPZ for whooping cough. Twelve cases were useful and 6 cases were slightly useful. 5) No side effects were observed except for elevation of GOT and LDH. These results suggest that CPZ might be useful drug against whooping cough.

Surgical treatment of spontaneous posterior interosseous nerve palsy: a retrospective study of 50 cases.

We have reviewed 38 surgically treated cases of spontaneous posterior interosseous nerve palsy in 38 patients with a mean age of 43 years (13 to 68) in order to identify clinical factors associated with its prognosis. Interfascicular neurolysis was performed at a mean of 13 months (1 to 187) after the onset of symptoms. The mean follow-up was 21 months (5.5 to 221). Medical Research Council muscle power of more than grade 4 was considered to be a good result. A further 12 cases in ten patients were treated conservatively and assessed similarly. Of the 30 cases treated surgically with available outcome data, the result of interfascicular neurolysis was significantly better in patients < 50 years old (younger group (18 nerves); good: 13 nerves (72%), poor: five nerves (28%)) than in cases > 50 years old (older group (12 nerves); good: one nerve (8%), poor: 11 nerves (92%)) (p < 0.001). A pre-operative period of less than seven months was also associated with a good result in the younger group (p = 0.01). The older group had a poor result regardless of the pre-operative delay. Our recommended therapeutic approach therefore is to perform interfascicular neurolysis if the patient is < 50 years of age, and the pre-operative delay is < seven months. If the patient is > 50 years of age with no sign of recovery for seven months, or in the younger group with a pre-operative delay of more than a year, we advise interfascicular neurolysis together with tendon transfer as the primary surgical procedure.