Low-lying excited states of light-harvesting system II in purple bacteria

The low-lying excited states of a B850 ring of Rhodospirillum (Rs.) molischianum are determined accurately by a semiempirical INDO/S method. Results obtained are found to fit extremely well with a Frenkel exciton model with long-range dipolar interactions, and the spatial size of the electron-hole pair is confirmed to fall predominantly within one bacteriochlorophyll with a small leakage to its nearest neighbors. More importantly, the nearest neighbor exciton coupling constants are found to be close to those evaluated directly from dimers, and thus, an existing discrepancy between calculated results of dimers and B850 rings has been resolved.

Hydrogen-based tubular catalytic membrane for removing nitrate from groundwater

A porous tubular ceramic membrane coated with palladium-cupper (Pd-Cu) catalyst on its surface was prepared and evaluated for catalytic reduction of nitrate from groundwater. Nitrate reduction activity and selectivity with the catalytic membrane were compared with Pd-Cu/Al2O3 catalyst particles. The catalytic membrane reactor exhibited a better selectivity by enabling an effective control of hydrogen gas, thus minimizing ammonium production. No leaching of palladium and copper into aqueous phase was observed, thereby indicating a high chemical stability of the metallic ions on the carrier support. This was also evidenced by the X-ray photoelectron spectroscopy (XPS) profiles of fresh and used catalysts, which showed no significant difference in surface compositions. Due to its higher selectivity in nitrate reduction and better flexibility in terms of operating conditions, the tubular catalytic ceramic membrane could be useful in removing nitrate from groundwater.

Predictive factors of the long-term outcome in reflux esophagitis in a low-prevalence gastroesophageal reflux disease region

BACKGROUND

There are no data concerning the long-term outcome of patients with reflux esophagitis in Taiwan. In this study the outcome and the specific prognostic indicators associated with outcome in patients were assessed retrospectively, 7 years after diagnosis of esophagitis.

METHODS

The study comprised a total of 128 patients with endoscopic esophagitis, diagnosed between January and June 1995, at Taichung Veterans' General Hospital. The outcome at 7 years after diagnosis was assessed by outpatient or telephone interview. Factors associated with requiring long-term acid suppression therapy were analyzed.

RESULTS

In all, 105 patients were eligible for analysis: 61 patients (58.1%) with LA (Los Angeles classification) grade A, 29 patients (27.6%) with grade B, 11 patients (10.5%) with grade C and 4 patients (3.5%) with grade D esophagitis. Seven years after diagnosis, there were 52 patients (49.5%) with no or occasional reflux symptoms, 8 patients (7.6%) with occasional symptoms requiring treatment with histamine-2 receptor antagonists (H2RAs), 12 patients (11.4%) with occasional symptoms requiring treatment with proton pump inhibitors (PPIs), as needed, and 33 patients (31.3%) with sustained symptoms needing daily maintenance with PPIs.

CONCLUSION

Nearly 50% of patients in Taiwan with endoscopic esophagitis still required treatment 7 years after diagnosis. Approximately 31% of patients still required daily acid suppression therapy. Presence of hiatal hernia and the severity of esophagitis at initial endoscopy independently were predictive of those who would require long-term acid suppression therapy.

Energy dissipation mechanisms in carbon nanotube oscillators

Energy transfer from the translational degrees of freedom to phonon modes is studied for isolated systems of two coaxial carbon nanotubes, which may serve as a nearly frictionless nano-oscillator. It is found that for oscillators with short nanotubes (less than 30 A) a rocking motion, occurring when the inner tube is pulled about 1/3 out of the outer tube, is responsible for significant phonon energy acquisitions. For oscillators with long nanotubes translational energies are mainly dissipated via a wavy deformation in the outer tube undergoing radial vibrations. Frictional forces between 10(-17) and 10(-14) N per atom are found for various dissipative mechanisms.

Sepsis-induced immunosuppression: from bad to worse

The sepsis syndrome is characterized by the acute release of a variety of inflammatory mediators, which often result in detrimental effects to the host. The release of these mediators is regulated and counterbalanced by the coordinated expression of antiinflammatory molecules. It is the balance between the expression of pro- and antiinflammatory mediators that often determines the magnitude of early tissue injury and subsequent risk of infectious complications. As our understanding of the pathophysiology of sepsis continues to evolve, we have gained a greater appreciation for the effects that sepsis and similar states of overwhelming stress have on host antimicrobial immunity. A number of functional defects in leukocytes isolated from sepsis patients have been characterized. These defects include diminished expression of important cell surface antigens, dysregulated cytokine production, alterations in antigen-presenting ability, and accelerated apoptosis. Impaired leukocyte function has important clinical ramifications, as high mortality rates have been observed in patients displaying evidence of sepsis-induced immune deactivation. In this article, we review the current literature supporting evidence of dysregulation of host immunity occurring during sepsis syndrome, characterize the underlying pathophysiology, and describe novel therapeutic interventions directed at augmenting host immunity during sepsis.

Density matrix negativity for two oscillators in an Agarwal bath

A system of two harmonic oscillators is placed in an Agarwal bath. The resulting quantum master equations are studied with the help of quantum characteristic functions. The density matrix positivity is investigated in view of the recent interest in searching for a sound quantum dissipation theory. An analytical criterion is derived for density matrix negativity for two uncoupled oscillators. It is found that, for an initial two-oscillator squeezed state with a real squeezing parameter s, density matrix negativity occurs for two uncoupled oscillators at temperatures lower than Planck's over 2 pi omega/(k(B) ln coth/s/) with omega the oscillator frequency and k(B) the Boltzmann factor. As a by-product an analytical expression is also obtained for determining the quantum separability of two uncoupled oscillators. The effects of interoscillator coupling on density matrix negativity are discussed.

Effect of electrical stimulation on acupuncture points in diabetic patients with gastric dysrhythmia: a pilot study

BACKGROUND/AIMS

Abnormal gastric slow-wave frequencies have been observed in diabetic gastroparesis and are associated with impaired antral motor activity. In this study, we aimed at evaluating the effect of acupuncture on gastric slow waves in diabetic patients with symptoms suggesting gastric motor dysfunction.

METHODS

Fifteen patients with type II diabetes who had had dyspeptic symptoms for more than 3 months were enrolled. Two acupuncture needles were inserted into the subjects' legs at the Zusanli points, and electrical stimulation (2-Hz pulses) was delivered for 30 min. Cutaneous electrogastrography was performed for 30 min at baseline, for 30 min during acupuncture, and for an additional 30 min after acupuncture. Serum gastrin, motilin, and human pancreatic polypeptide levels were also measured.

RESULTS

There was a significant increase in the percentages of normal frequency during and after acupuncture (baseline vs. acupuncture and after acupuncture 21.99 +/- 19.38% vs. 45.93 +/- 19.72 and 48.92 +/- 19.56%; p < 0.01). In addition, the percentage of tachygastric frequency was decreased significantly during and after acupuncture. The dominant frequency was also changed significantly. There was an increase of serum human pancreatic polypeptide during acupuncture (baseline vs. acupuncture 56.96 +/- 27.64 vs. 73.11 +/- 22.37 pmol/l; p < 0.05).

CONCLUSIONS

The results of this study revealed that electrical stimulation at the Zusanli points could increase the percentage of normal electrogastrography frequency and decrease the percentage of tachygastric frequency in diabetic patients. The data indicate that acupuncture may enhance the regularity of gastric myoelectrical activity in diabetic patients.

Primary resistance to antibiotics and its clinical impact on the efficacy of Helicobacter pylori lansoprazole-based triple therapies

AIM

To evaluate Helicobacter pylori primary resistance and its clinical impact on the efficacy of two lansoprazole-based eradication triple therapies.

METHODS

H. pylori-positive patients (n=228) were randomized to receive one of the 1-week regimens: lansoprazole 30 mg, clarithromycin 500 mg and amoxicillin 1 g (LAC), or lansoprazole 30 mg, clarithromycin 500 mg and metronidazole 500 mg (LMC), each given twice daily. H. pylori status was assessed by 13C-urea breath test and culture at diagnosis and by 13C-urea breath test 6 weeks after therapy. Antibiotic susceptibility was determined by E-test (n=98).

RESULTS

The eradication rates with per protocol/ intention-to-treat analyses were: LAC (n=95/114) 83%/69% and LMC (n=96/114) 85%/72%. Primary resistance was 11% for clarithromycin, 41% for metronidazole and 0% for amoxicillin. Eradication in metronidazole-susceptible/-resistant strains was 85%/82% in LAC and 83%/63% in LMC. Significantly lower cure rates were observed in clarithromycin-resistant patients treated with LAC (95% vs. 0%, P < 0.001) and LMC (86% vs. 0%, P < 0.001).

CONCLUSIONS

One-week LAC and LMC are similarly effective therapies. Clarithromycin resistance significantly affected H. pylori eradication in both regimens.

Salinity effect on mechanical dewatering of sludge with and without chemical conditioning

The salinity levels of wastewater and sludge are relatively high in some coastal cities as they may use saline water for toilet flushing, and as such,the sludge dewaterability can be affected by it. The salinity effect on sludge dewaterability was therefore investigated through experimental testing of specific resistance in filtration (SRF), time to filter (TTF), and final solid content of sludge. SRF and TTF were determined using Buchner funnel tests. The final solid content was estimated by centrifuging the sludge at four levels of rotational speed. Sludge with three salinity levels (5,000, 10,000 and 20,000 ppm) were considered in this study. Coagulants such as alum, iron(II) sulfate, and organic polyelectrolytes were added to the sludgetostudythe dewaterability of such sludge with chemical conditioning. Experimental results show that doubling the salinity level of the sludge from 10,000 to 20,000 ppm shows not much change in SRF and TTF. Compared with the sludge without chemical conditioning, the addition of the coagulants to the sludge at a salinity level of 5,000 ppm drastically reduces its SRF and TTF. However, sludge with and without chemical conditioning at a salinity of 20,000 ppm has similar SRF and TTF. The final solid content of sludge increases almost linearly with salinity. Among the coagulants used in this study, the cationic polyelectrolyte is found to be better in improving sludge dewaterability, while iron(II) sulfate performs slightly better in enhancing the final solid content of the sludge.

Expression and clinical significance of antinuclear antibody in hepatitis C virus infection

BACKGROUND

The prevalence of antinuclear antibody (ANA) has been documented in patients with hepatitis C virus (HCV) infection. We attempted to determine the titer and to characterize the patterns and clinical significance of ANA in HCV infection.

STUDY

Forty-eight consecutive patients with positive anti-HCV antibody and positive HCV RNA were included in this study. Sera from patients were tested for ANA and anti-smooth muscle antibody by indirect immunofluorescence. Serum aminotransferase, alkaline phosphatase, alpha-fetoprotein, and cryoglobulin levels also were determined.

RESULTS

Eleven (23%) of 48 HCV-infected patients were positive for ANA. Antinuclear antibody revealed speckled pattern in 10 (91%) of the 11 ANA-positive HCV-infected patients. Twenty (54%) of 37 ANA-negative HCV-infected patients had detectable pattern with equivocal titer (titer <1.5). The ANA pattern was speckled in all 20 patients. Hepatitis C virus-infected patients with positive ANA were older than the HCV-infected patients with negative ANA (62.90 +/- 11.05 years vs. 56.46 +/- 14.94 years, respectively; p < 0.1). Serum levels of aspartate aminotransferase (39.36 +/- 14.98 IU/L vs. 30.70 +/- 23.15 IU/L, p < 0.05), alkaline phosphatase (189.00 +/- 75.63 IU/L vs. 122.41 +/- 40.88 IU/L, p < 0.01), and alpha-fetoprotein (47.72 +/- 80.47 pg/dL vs. 7.00 +/- 8.28 pg/dL, p < 0.01) were higher in ANA-positive HCV-infected patients than in ANA-negative HCV-infected patients, respectively. There were no significant differences in gender, alanine aminotransferase, anti-smooth muscle antibody, or cryoglobulin between the two groups.

CONCLUSIONS

Antinuclear antibody was present in 11 (23%) of 48 patients with HCV infection in our study. Speckled pattern is the major expression pattern of ANA in HCV infection. Antinuclear antibody-positive HCV-infected patients have significantly higher serum aspartate aminotransferase, alkaline phosphatase, and alpha-fetoprotein levels than ANA-negative HCV-infected patients.

[Separation of xylose and xylitol in fermentation liquid by capillary zone electrophoresis]

Xylitol may be produced with microbial fermentation technology when xylose is used as the raw material. It is important in scientific research and production fields concerned with xylose and xylitol to develop the method of separation and detection. The anionic complexes with strong UV absorption at 195 nm will form by dissolving xylose and xylitol in borax solution. They may be separated with borax buffer by use of capillary zone electrophoresis. It was shown that the resolution between xylose and xylitol gradually increased with the increase of borax concentration, but its maximum concentration was 130 mmol/L at room temperature. The resolution depended on the pH of running buffer with a maximum at pH 9.55. The resolution was independent of cetyltrimethylammonium bromide when its concentration was between 4 x 10(-6) mmol/L-8 x 10(-4) mmol/L. So the optimum conditions were as follows: borax concentration of 130 mmol/L, pH 9.55 and cetyltrimethylammonium bromide concentration of 5 x 10(-5) mmol/L in running buffer; separating voltage of -12 kV; column temperature of 25 degrees C. Xylose and xylitol could be separated on base line in 6 min under these conditions. Samples from fermentation process and the recoveries of spiked samples were determined. The relative standard deviations of the results were between 1.42%-3.11% for xylose, and 0.62%-1.32% for xylitol. The recoveries were between 96.0%-108.0% for xylose and 94.0%-109.0% for xylitol.

Expression of soluble form carp (Cyprinus carpio) ovarian cystatin in Escherichia coli and its purification

A DNA encoding thioredoxin-mature carp ovarian cystatin (trx-cystatin) fusion protein was ligated into a pET-23a(+) expression vector and then transformed into Escherichia coli AD494(DE3) expression host. After induction by isopropyl beta-D-thiogalactopyranoside, a high level of the soluble form of recombinant trx-cystatin was expressed in the cytoplasm of E. coli. The recombinant trx-cystatin could be purified by Ni(2+)-NTA agarose affinity chromatography. The molecular mass (M) of the recombinant trx-cystatin was approximately 28 kDa composed of recombinant thioredoxin (16 kDa) and recombinant mature carp ovarian cystatin (12 kDa). Both recombinant trx-fused and mature carp ovarian cystatins were stable at pH 6-11. No obvious decrease in activity was observed even after 5 min of incubation at 60 degrees C. They exhibited papain-like protease inhibition activity comparable to that of the mature carp ovarian cystatin, which could inhibit papain and mackerel cathepsins L and L-like, but not cathepsin B.

Selective inhibition of COX-2 improves early survival in murine endotoxemia but not in bacterial peritonitis

Prostaglandins of the E series are believed to act as important mediators of several pathophysiological events that occur in sepsis. Studies were performed to evaluate the effect of cyclooxygenase (COX)-2-specific inhibition on the outcome in murine endotoxemia and cecal ligation and puncture (CLP). We observed a significant time-dependent upregulation of PGE(2) production in both blood and lung homogenates of mice administered lipopolysaccharide intraperitoneally, which was nearly completely suppressed by the administration of the COX-2 inhibitor NS-398. Treatment with NS-398 significantly improved early but not late survival in lipopolysaccharide-challenged mice. On the contrary, elevated PGE(2) levels were found in bronchoalveolar lavage fluid but not in plasma of mice subjected to CLP (21 gauge). Pretreatment with NS-398 failed to significantly improve survival in CLP mice. No significant differences were noted in plasma or lung homogenate proinflammatory cytokine levels or lung neutrophil sequestration between the NS-398-treated and control groups. These results demonstrate that selective COX-2 inhibition confers early but not long-term benefits without affecting the expression of proinflammatory cytokines or the development of lung inflammation.

[Analysis of amino acids and vitamins in ginkgo biloba leaves]

The contents of amino acids and 10 kinds of vitamins in ginkgo biloba leaves were analyzed via HPLC. The results shows that it contains 92.26 mg amino acids per gram leaves the rate of essential amino acids amount to total amino acids amount is 46.9% and the contents of Vc, Vpp, VE, VB6, PGA is 81.47 mg, 9.43 mg, 4.09 mg, 2.90 mg, 1.69 mg per gram leaves respectively. The present effective data will be helpful for further research in its chemical composition and comprehensive utilization.

The correlation of depression and gastric dysrhythmia in functional dyspepsia

Psychologic factors in functional dyspepsia have been discussed in many previous articles. However, the relationship between depression and functional dyspepsia is still obscure. We investigated the impact of depression on clinical symptoms and gastric dysrhythmia in functional dyspepsia. Thirty-nine patients with functional dyspepsia and 18 healthy subjects were included. Patients were investigated with clinical symptoms assessment, Zung's self-rating depression scale, and electrogastrography. Patients with functional dyspepsia were divided into two groups: 21 patients with depression and 18 patients without depression. The depressed patients had similar total gastrointestinal symptom severity scores compared with the nondepressed patients, but with higher total symptom frequency scores (p < 0.05). With regards to symptoms, the depressed patients had higher abdominal fullness severity and frequency scores and nausea frequency scores. The patients with functional dyspepsia had a lower percentage of normal slow wave in both the fasting and fed states and a higher percentage of bradygastria in the fasting state and tachygastria in the postprandial state (p < 0.05). There was no significant difference in the percentage of bradygastria or tachygastria between the depressed and nondepressed patients. There was no correlation between the specific type of electrogastrographic abnormality and the presence or absence of depression in functional dyspepsia patients.

Hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome with acute cortical blindness

The coincidence of hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome and cortical blindness is an uncommon but very dramatic event. We describe a case of HELLP syndrome complicating with acute cortical blindness before delivery. A 27 year-old woman, gravida 1, para 0, with normal medical history, was referred to our emergency department at the 33th week of gestation due to headache, vomiting, and blurred vision. The ophthalmologic examination showed intact pupillary light reflexes and normal ophthalmoscopic findings, but no light perception in either eye. Brain computed tomography showed normal findings. HELLP syndrome and preeclampsia was diagnosed based on the findings of hypertension and proteinuria as well as laboratory data. Prompt delivery was performed in order to achieve good maternal and neonatal outcomes.