One-Year In Situ Incubation of Pyrite at the Deep Seafloor and Its Microbiological and Biogeochemical Characterizations.

In this study, we performed a year-long in situ incubation experiment on a common ferrous sulfide (Fe-S) mineral, pyrite, at the oxidative deep seafloor in the hydrothermal vent field in the Izu-Bonin arc, Japan, and characterized its microbiological and biogeochemical properties to understand the microbial alteration processes of the pyrite, focusing on Fe(II) oxidation. The microbial community analysis of the incubated pyrite showed that the domain Bacteria heavily dominated over Archaea compared with that of the ambient seawater, and Alphaproteobacteria and Gammaproteobacteria distinctively codominated at the class level. The mineralogical characterization by surface-sensitive Fe X-ray absorption near-edge structure (XANES) analysis revealed that specific Fe(III) hydroxides (schwertmannite and ferrihydrite) were locally formed at the pyrite surface as the pyrite alteration products. Based on the Fe(III) hydroxide species and proportion, we thermodynamically calculated the pH value at the pyrite surface to be pH 4.9 to 5.7, indicating that the acidic condition derived from pyrite alteration was locally formed at the surface against neutral ambient seawater. This acidic microenvironment at the pyrite surface might explain the distinct microbial communities found in our pyrite samples. Also, the acidity at the pyrite surface indicates that the abiotic Fe(II) oxidation rate was much limited at the pyrite surface kinetically, 3.9 × 103- to 1.6 × 105-fold lower than that in the ambient seawater. Moreover, nanoscale characterization of microbial biomolecules using carbon near-edge X-ray absorption fine-structure (NEXAFS) analysis showed that the sessile cells attached to pyrite excreted the acidic polysaccharide-rich extracellular polymeric substances at the pyrite surface, which can lead to the promotion of biogenic Fe(II) oxidation and pyrite alteration. IMPORTANCE Pyrite is one of the most common Fe-S minerals found in submarine hydrothermal environments. Previous studies demonstrated that the Fe-S mineral can be a suitable host for Fe(II)-oxidizing microbes in hydrothermal environments; however, the details of microbial Fe(II) oxidation processes with Fe-S mineral alteration are not well known. The spectroscopic and thermodynamic examination in the present study suggests that a moderately acidic pH condition was locally formed at the pyrite surface during pyrite alteration at the seafloor due to proton releases with Fe(II) and sulfidic S oxidations. Following previous studies, the abiotic Fe(II) oxidation rate significantly decreases with a decrease in pH, but the biotic (microbial) Fe(II) oxidation rate is not sensitive to the pH decrease. Thus, our findings clearly suggest that the pyrite surface is a unique microenvironment where abiotic Fe(II) oxidation is limited and biotic Fe(II) oxidation is more prominent than that in neutral ambient seawater.

Identification of the major Abeta1-42-degrading catabolic pathway in brain parenchyma: suppression leads to biochemical and pathological deposition.

Alzheimer amyloid beta-peptide (Abeta) is a physiological peptide constantly anabolized and catabolized under normal conditions. We investigated the mechanism of catabolism by tracing multiple-radiolabeled synthetic peptide injected into rat hippocampus. The Abeta1-42 peptide underwent full degradation through limited proteolysis conducted by neutral endopeptidase (NEP) similar or identical to neprilysin as biochemically analyzed. Consistently, NEP inhibitor infusion resulted in both biochemical and pathological deposition of endogenous Abeta42 in brain. This NEP-catalyzed proteolysis therefore limits the rate of Abeta42 catabolism, up-regulation of which could reduce the risk of developing Alzheimer's disease by preventing Abeta accumulation.

Metabolic regulation of brain Abeta by neprilysin.

Amyloid beta peptide (Abeta), the pathogenic agent of Alzheimer's disease (AD), is a physiological metabolite in the brain. We examined the role of neprilysin, a candidate Abeta-degrading peptidase, in the metabolism using neprilysin gene-disrupted mice. Neprilysin deficiency resulted in defects both in the degradation of exogenously administered Abeta and in the metabolic suppression of the endogenous Abeta levels in a gene dose-dependent manner. The regional levels of Abeta in the neprilysin-deficient mouse brain were in the distinct order of hippocampus, cortex, thalamus/striatum, and cerebellum, where hippocampus has the highest level and cerebellum the lowest, correlating with the vulnerability to Abeta deposition in brains of humans with AD. Our observations suggest that even partial down-regulation of neprilysin activity, which could be caused by aging, can contribute to AD development by promoting Abeta accumulation.

[Lung abscess which ruptured during the medical treatment of lung abscess; report of a case].

63-year-old man was admitted to our hospital with fever and cough for about 2 months. Laboratory data showed marked inflammatory changes, and chest computed tomography (CT) scans revealed right-sided hydrothorax, atelectasis of the right middle lobe, and a cystic mass in the right middle lobe. We diagnosed the patients as having lung abscess and empyema. Following the intravenous antibiotic chemotherapy, symptoms and laboratory data showed the improvement, however, on the 11th hospital day, he developed high fever again. A chest CT showed pneumopyothorax suggesting the rupture of lung abscess. Since the chest tube drainage was ineffective, open chest surgery was performed. Curettage of both thoracic and abscess cavity with closure of air leakage successfully cured the pyothorax.

Complete genome sequence of the alkaliphilic bacterium Bacillus halodurans and genomic sequence comparison with Bacillus subtilis.

The 4 202 353 bp genome of the alkaliphilic bacterium Bacillus halodurans C-125 contains 4066 predicted protein coding sequences (CDSs), 2141 (52.7%) of which have functional assignments, 1182 (29%) of which are conserved CDSs with unknown function and 743 (18. 3%) of which have no match to any protein database. Among the total CDSs, 8.8% match sequences of proteins found only in Bacillus subtilis and 66.7% are widely conserved in comparison with the proteins of various organisms, including B.subtilis. The B. halodurans genome contains 112 transposase genes, indicating that transposases have played an important evolutionary role in horizontal gene transfer and also in internal genetic rearrangement in the genome. Strain C-125 lacks some of the necessary genes for competence, such as comS, srfA and rapC, supporting the fact that competence has not been demonstrated experimentally in C-125. There is no paralog of tupA, encoding teichuronopeptide, which contributes to alkaliphily, in the C-125 genome and an ortholog of tupA cannot be found in the B.subtilis genome. Out of 11 sigma factors which belong to the extracytoplasmic function family, 10 are unique to B. halodurans, suggesting that they may have a role in the special mechanism of adaptation to an alkaline environment.

Proton pump inhibitor after endoscopic resection for esophageal squamous cell cancer: multicenter prospective randomized controlled trial.

BACKGROUND: Whether proton pump inhibitors (PPIs) relieve heartburn or precordial pain after endoscopic resection (ER) for esophageal squamous cell carcinoma (ESCC) remains unclear. The aim of this study was to investigate the efficacy of PPI therapy for these symptoms after ER for ESCC. METHODS: We conducted a multicenter prospective randomized controlled trial among 15 hospitals in Japan. In total, 229 patients with cT1a ESCC were randomly assigned to receive PPI therapy for 5 weeks after ER (the PPI group, n = 115) or follow-up without PPI therapy (the non-PPI group, n = 114). The primary end point was the incidence of gastroesophageal reflux disease (GERD)-like symptoms after ER from a self-reported questionnaire (Frequency Scale for Symptoms of GERD). Secondary end points were ulcer healing rate at 5 weeks, incidence of pain, improvement rate of symptoms in those who started PPI therapy because of GERD-like symptoms in the non-PPI group, and adverse events. RESULTS: No significant difference was observed in the incidence of GERD-like symptoms after ER between the non-PPI and PPI groups (30 % vs 34 %, respectively). No significant differences were observed in the ulcer healing rate at 5 weeks (84 % vs 85 %) and incidence of pain within 1 week (36 % vs 45 %). In nine of ten patients (90 %) who started PPI therapy because of GERD-like symptoms in the non-PPI group, PPI administration relieved GERD-like symptoms. No adverse events related to PPI administration were observed. CONCLUSION: PPI therapy is not efficacious in reducing symptoms and did not promote healing of ulcers in patients undergoing ER for ESCC.

Molecular cloning and expression of aminopeptidase A isoforms from rat hippocampus.

The full-length cDNA encoding aminopeptidase A (APAL) was cloned from a rat hippocampus cDNA library. A short variant aminopeptidase A (APAS), produced by deletion, was also cloned. In the case of APAL, the longest open reading frame encodes 945 amino acid residues with a calculated molecular mass of 108 kDa, and the deduced amino acid sequence shows 76, 86 and 78% identity with its human, murine and porcine counterparts, respectively. Rat aminopeptidase A mRNAs were detected in the kidney, liver, heart and brain by Northern blot analysis. When overexpressed in COS-1 cells, APAL shows apparent aminopeptidase A activity, whereas APAS does not.

Quantification of renal uptake of technetium-99m-DTPA using planar scintigraphy: a technique that considers organ volume.

We developed a method to estimate the radioactivity of 99mTc-DTPA within the kidney by planar scintigraphy. Phantom experiments and renal studies were used to compare our method with that of the Gates' method. Our method corrects for scatter and attenuation using the volume depth-independent buildup factor technique, after which background correction is performed with consideration for target organ volume. When the renal phantom-to-background activity concentration ratio (S) was changed from 5 to 80 in a water-filled container and the renal phantom depth was varied from 1 to 11 cm for each value of S, the renal phantom count rate calculated by our method was accurate under all conditions investigated. In contrast, the Gates' method was significantly affected by phantom depth and S values. In 40 patients, renal uptake in the image obtained 2-3 min after injection of 99mTc-DTPA was estimated by our method and the Gates' method, and the correlation between uptake and creatinine clearance was determined. When a ring background region of interest (ROI) around the kidney was employed, a good correlation was obtained by our method (r = 0.947) in comparison with the Gates method (r = 0.887). With both methods, a semilunar background ROI produced poor results than the ring background ROI. In conclusion, renal radioactivity levels that correlate well with creatinine clearance can be obtained by our method, which allows estimation of individual glomerular filtration rates.

Biochemical identification of the neutral endopeptidase family member responsible for the catabolism of amyloid beta peptide in the brain.

Amyloid beta peptide (Abeta) is a physiological peptide that is constantly catabolized in the brain. We previously demonstrated that an endopeptidase sensitive to phosphoramidon and thiorphan conducts the initial rate-limiting proteolysis of Abeta in vivo, but the exact molecular identity of the peptidase(s) has remained unknown because of the molecular redundancy of such activity. We analyzed the brain-derived enzyme by means of immuno-depletion and gene disruption, and demonstrate here that neprilysin accounts for the majority of the Abeta-degrading activity. Furthermore, kinetic analysis, giving a K(m) value of 2.8 +/- 0.76 microM, indicated that Abeta(1-42) is a relevant substrate for neprilysin.

Cloning and expression of the gene encoding RNA polymerase alpha subunit from alkaliphilic Bacillus sp. strain C-125.

The rpoA gene, encoding the alpha subunit of RNA polymerase, was isolated from alkaliphilic Bacillus sp. strain C-125 by the PCR method. A 3-kb HindIII fragment containing the complete rpoA gene was cloned and sequenced. The alpha subunit gene was found to encode a protein consisting of 314 amino acid residues with a molecular mass of 34,805 Da. Compared with the amino acid sequences of other known eubacterial RNA polymerase alpha subunits, the gene has 84% identity to that of B. subtilis, while showing 48% and 47% identity to that of Streptomyces coelicolor and Escherichia coli, respectively. Six conserved regions, which are observed in the case of other eubacteria, were found in the RNA polymerase alpha subunit of this strain. Five of them are located in the N-terminal domain involved in assembly of the core enzyme, while one is located in the C-terminal domain, which interacts with several transcriptional factors and a specific DNA element. By means of recombinant plasmids, a hexahistidine-tagged derivative of the RNA polymerase alpha subunit of strain C-125 and two deletion derivatives (C- and N-terminal domains) of this protein were overexpressed in E. coli cells and purified to near homogeneity.

A preliminary phantom study on a proposed model for quantification of renal planar scintigraphy.

A method for estimation of the absolute renal activity within background activity in renal planar scintigraphy will be presented. This method corrects for oversubtraction of background activity with consideration of background activity of the kidney volume, and employs the depth-independent buildup factor (DIBF) method for the correction of attenuation and scatter of photons. This method requires the depth and thickness of the organ and the thickness of background for a background activity correction. The transmission factor (TF) for a volume source is derived from integrating TF for a thin source over the thickness of the organ for the DIBF method. To validate this method, phantom studies with various uniform background activity concentrations were performed and the data were compared with conventional background subtraction that do not consider the organ's volume. The results showed that with the conventional background subtraction method at all depth activity was underestimated with errors of 5%-30% for organ/background concentration ratios of 5-40, while this method estimated the true count rate with errors of less than 5%. More accurate quantifications of renal functions such as renal uptake, glomerular filtration rate (GFR) and renogram may be obtained by this proposed method on the planar images.

Second-line chemotherapy with weekly cisplatin and irinotecan in patients with refractory lung cancer.

Cisplatin and irinotecan are reported to act synergistically. The authors have conducted a phase II trial combining cisplatin and irinotecan in patients with refractory lung cancer to evaluate the activity and safety of the regimen. Twenty-one patients, who had not responded to prior platinum-based chemotherapy, were entered into the study. Both cisplatin (30 mg/m2) and irinotecan (60 mg/m2) were administrated on days 1, 8, and 15, and the regimen was repeated every 28 days. There were six partial responses, and the response rate was 29% (95% confidence interval, 11.3%-52.2%). The median survival time of all patients was 32 weeks, and 1-year and 2-year survival rates were 43% and 11%, respectively. Major toxicities were hematologic; leukopenia of grades 3 and 4 developed in 43% patients, anemia developed in 38%, and thrombocytopenia developed in 19%. One notable nonhematologic toxicity was diarrhea; which was grade 3 in 38%. The weekly chemotherapy combining cisplatin and irinotecan was active against lung cancer, which is refractory to platinum-based chemotherapy. However, skips of drug administration or dose reduction were necessary in 76% patients during two courses of planned administration, though the ratio of actual dose to scheduled dose was 81%. Dose modification would be necessary to yield better results by this weekly chemotherapy.

Correction of scattered photons in Tc-99m imaging by means of a photopeak dual-energy window acquisition.

We are proposing a new method for correcting of scattered photons in technetium-99m (99mTc) imaging by means of photopeak dual-energy window acquisition. This method consists of the simultaneous acquisition of two images and estimation of a scatter image included in the symmetric energy window (SW) image by the difference between these images. The scatter corrected image is obtained by subtracting the scatter image from the SW image. In order to evaluate this method, we imaged a planar and a SPECT phantom with cold lesions and calculated the contrast value with and without the scatter correction. In addition, we performed asymmetric energy window (ASW) imaging to compare with this scatter correction method for planar images. In the planar image with the tissue-equivalent material of 10 cm, the scatter correction method removed 32% of the counting rate of the SW image and improved from 0.81 to 0.94 of the contrast value for a 4 cm-diameter cold lesion, while the contrast value with the ASW was 0.87 for such a cold lesion. The scatter corrected SPECT image had a reduction of 18% of the counting rate of the SW SPECT image and improvement of approximately 11% in contrast for cold spot sizes larger than a 3 cm-diameter, compared with the SW SPECT image. In addition, a perfusion defect could be well visualized by this scatter correction method on 99mTc-HMPAO regional cerebral blood flow SPECT of a patient. Our proposed scatter correction method can improve both planar and SPECT images qualitatively and quantitatively.

Quantitative renography with the organ volume method and interporative background subtraction technique.

When quantification of renal activity is performed by planar imaging, many correction factors must be considered. To obtain quantitative renal images and renogram, we have examined our proposed method by using the organ volume for scatter, attenuation, and background activity, and the interporative background subtraction (IBS) technique in phantom and clinical studies. A renal phantom study was performed by varying the renal depth from 3 to 11 cm and the kidney-to-background activity concentration ratio from 5 to 80. Planar images were properly corrected for scatter, attenuation and background activity by our method and the corrected images were compared with the images obtained by the conventional method for the estimation of true renal activity. Clinical Tc-99m DTPA dynamic data for both a good and a poor renal function were also corrected by our method and volume-corrected renograms were obtained. For the phantom study, depth-independent images were obtained and these images gave a good estimation of the true count rate. In the clinical study, the conventional renogram was especially modified to allow for oversubtraction of background counts in the early phase (0-4 min). In conclusion, our proposed correction method can assess renal function qualitatively and quantitatively in both static and dynamic planar renal imaging.

Spontaneous tumors in F-344/Jcl rats.

The age-related incidence of spontaneously occurring neoplastic and non-neoplastic lesions in untreated F-344/Jcl rats, used as controls in carcinogenicity testing, were studied from the histological examination of tissues from 469 males and 354 females. The incidence of spontaneous tumors was 83.2% in the males and 71.2% in the females. The most common neoplasms were leukemia (males: 24.3%, females: 24.0%), pituitary adenoma (males: 16.0%, females: 45.2%), pheochromocytoma (males: 14.7%, females: 7.3%), testicular interstitial cell tumor (males: 79.1%), and uterine endometrial stromal polyp(females: 16.4%). The incidence of other tumors of almost all the organs and/or tissues was low. Non-neoplastic lesions generally increased with advancing age of the animals.

Immunological studies of pityriasis rosea (Gibert).

In order to elucidate the immunological mechanism in the pathogenesis of pityriasis rosea, immunofluorescent studies were performed on sera obtained from forty patients with this disease. Antibodies against the cytoplasm of normal human epidermal cells were demonstrated in the sera of all patients. The antibody titer showed a tendency to increase within 3 weeks after onset of secondary eruptions and then to decrease gradually until the period of recovery. The immunoglobulin class was determined to be IgM. Furthermore, by the direct immunofluorescent technique, deposits of IgM in the epidermal cells of skin lesions were demonstrated in 3 of 6 herald lesions and in 1 of 4 secondary eruptions. It is suggested that anti-cytoplasmic antibodies produced by some unknown cause may induce the development of secondary eruptions of this disease.

Measurement of effective renal plasma flow (ERPF) with 123I-orthoiodohippurate (I-123-OIH).

We evaluated the necessity of attenuation correction for calculating effective renal plasma flow (ERPF) using I-123-orthoiodohippurate (OIH), an agent introduced recently to replace I-131-OIH. From a kidney phantom experiment, the attenuation coefficient (mu) for I-123-OIH in the human body was determined as 0.1262 cm-1. I-123-OIH renal scintigraphy was performed in 23 patients with urinary diseases with blood sampling for calculation of ERPF by Tauxe's method. Calculated renal uptake, with or without attenuation correction, was compared with ERPF determined by Tauxe's method. There was good correlation between renal uptake without attenuation correction and ERPF obtained by Tauxe's method (r = 0.737), while much better correlation was found between attenuation-corrected renal uptake and ERPF calculated by Tauxe's method (r = 0.816). In conclusion, attenuation correction for renal uptake is an important technique for estimating ERPF using I-123-OIH renal scintigraphy.

[Development of a perceived social support scale: for a Japanese population].

Social support is increasingly attracting interest in as a factor in epidemiological research of disease risks. However, at present, few methods for measuring social support that can be credited as having reliability and validity exist in Japan. Therefore a perceived social support scale was developed in relation to a population study of a town in Fukuoka prefecture. A method for measuring functional support from several external sources was designed consisting of a self-administered test provided with only two available response options--yes & no. Pretests were conducted twice in order to evaluate content validity and adjust the number of determinants and resulted in spouse, family members, and friends being selected to be primary sources of support. A factor analysis was applied to select 10 conditions with high internal consistency for each of the sources. Responses were scored 0 or 1, for 'no' or 'yes,' respectively. Subsequently each set of 10 variables was summed into an index ranking social support conditions for each of the three sources. The three highest ranking indicators from each of the respective sources were then integrated into a single comprehensive total social support score of the individuals. The inquiry method was applied on 277 adults, aged from 40 to 69 years, in the town. Intercorrelation between the indicators of support derived from the three sources was low and coefficients of reliability ranged from 0.892 to 0.978. The score of each set of the 10 variables were incorporated into a principal components analysis in order to determine factorial validity. All of the first factor loadings of the items measuring support from both spouse and family were greater than 0.7 and high eigenvalues were obtained. Therefore the methods applied to spouse and family were considered adequate to measure a given construct. The items measuring support from friends were divided into two factors, emotional support and tangible support.

[Changes in intraoperative and postoperative colloid oncotic pressure after open heart surgery especially in relation to non-blood priming or blood priming].

In order to evaluate the colloid oncotic pressure (COP) is useful index of hemodynamics and respiratory recovery after open heart surgery, cardiac index (CI), pulmonary capillary wedge pressure (PCWP), (A-a) Do2 and COP were measured in 34 patients during 48 hours after the cardiopulmonary bypass (CPB). The patients were divided into non-blood priming group: 11 patients and blood priming group (23 patients). In addition, blood priming group divided into two groups, one with dopamine (more than 15 micrograms/kg/min), epinephrine or intraaortic balloon pumping (severe blood subgroup, n = 6) and the other without these treatments after open heart surgery (slight blood subgroup n = 17). The COP levels in the non-blood priming group were significantly higher than those in the blood priming group from aortic cross-clamp to 10 minutes after aortic declamping (p < 0.01). From 1 to 48 hours after CPB, COP in the non-blood priming group and slight blood subgroups was significantly higher than severe blood subgroups (p < 0.05). CI and COP-PCWP levels were significantly higher in the non-blood priming group and slight blood subgroups than those in the severe blood group (p < 0.05). It is concluded that COP is useful index of hemodynamics and respiratory recovery after open heart surgery and our priming system without blood is effective in order to eliminate the blood transfusion.