Supersulphides provide airway protection in viral and chronic lung diseases

Supersulphides are inorganic and organic sulphides with sulphur catenation with diverse physiological functions. Their synthesis is mainly mediated by mitochondrial cysteinyl-tRNA synthetase (CARS2) that functions as a principal cysteine persulphide synthase (CPERS). Here, we identify protective functions of supersulphides in viral airway infections (influenza and COVID-19), in aged lungs and in chronic lung diseases, including chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF). We develop a method for breath supersulphur-omics and demonstrate that levels of exhaled supersulphides increase in people with COVID-19 infection and in a hamster model of SARS-CoV-2 infection. Lung damage and subsequent lethality that result from oxidative stress and inflammation in mouse models of COPD, IPF, and ageing were mitigated by endogenous supersulphides production by CARS2/CPERS or exogenous administration of the supersulphide donor glutathione trisulphide. We revealed a protective role of supersulphides in airways with various viral or chronic insults and demonstrated the potential of targeting supersulphides in lung disease.

Retroperitoneal leiomyosarcoma: a case report

Retroperitoneal leiomyosarcoma is a relatively rare and aggressive tumor. Because of its rarity, it is difficult to arrive at a definite diagnosis preoperatively and to design an effective strategy. Here the authors report a case of peritoneal leiomyosarcoma in which diagnosis was difficult because the clinical course resembled that of ovarian cancer. A 77-year-old woman diagnosed with ovarian cancer underwent laparotomy. The excised tumor contained a necrotic polypoid mass that histologically displayed the features of leiomyosarcoma. The patient received adjuvant chemotherapy with a combination of gemcitabine and docetaxel but died two months after surgery owing to the aggressive behavior of the tumor. Because the preoperative diagnosis in this case was ovarian cancer, arriving at a treatment strategy assuming peritoneal leiomyosarcoma was difficult. If complete surgical resection of tumor is not performed, as in the present case, the prognosis can be extremely poor.

Relationship between the Peripheral Lymphocyte Response to Mycophenolic Acid in vitro and the Level of ATP in Peripheral CD4+ Lymphocytes before and after Renal Transplantation

OBJECTIVE

The lymphocyte immunosuppressant sensitivity test has been used to predict the pharmacodynamics of immunosuppressive drugs for the purpose of preventing acute rejection and infection after renal transplantation. On the other hand, measuring the ATP levels in peripheral CD4+ lymphocytes is also able to monitor the risks of rejection and infection in transplant recipients. In the present study, we examined the relationship between the mycophenolic acid pharmacodynamics and the ATP levels in peripheral lymphocytes before and after renal transplantation.

METHODS

We examined both the pharmacological efficacy of mycophenolic acid and the lymphocyte ATP levels before and 2, 4 and 6 weeks after the operation in 20 renal transplant recipients. The drug's pharmacological efficacy was evaluated by the 50% inhibitory concentration of the drug against the in vitro proliferation of peripheral blood lymphocytes activated by T cell mitogen. The ATP levels in peripheral CD4+ lymphocytes were measured by the Immuknow assay kit. The relationships between the mycophenolic acid pharmacodynamics and ATP levels in peripheral lymphocytes were examined in these recipients.

RESULTS

The immunosuppressive effects of mycophenolic acid against mitogen-activated lymphocyte proliferation were significantly and positively correlated with the lymphocyte ATP levels, but only at 6 weeks after transplantation. The relationship was not significant before or at 2 or 4 weeks after the operation.

CONCLUSION

Our present data raised the possibility that evaluating the pharmacological efficacy of mycophenolic acid pre-transplantation and monitoring the ATP level 6 weeks after transplantation can predict the risk of rejection and/or infection in renal transplant recipients.

Quantitative structural characterization of local N-glycan microheterogeneity in therapeutic antibodies by energy-resolved oxonium ion monitoring

Site-specific characterization of glycoform heterogeneity currently requires glycan structure assignment and glycopeptide quantification in two independent experiments. We present here a new method combining multiple reaction monitoring mass spectrometry with energy-resolved structural analysis, which we termed "energy-resolved oxonium ion monitoring". We demonstrated that monitoring the yields of oligosaccharide-derived fragment ions (oxonium ions) over a wide range of collision induced dissociation (CID) energy applied to a glycopeptide precursor exhibits a glycan structure-unique fragmentation pattern. In the analysis of purified immunoglobulin glycopeptides, the energy-resolved oxonium ion profile was shown to clearly distinguish between isomeric glycopeptides. Moreover, limit of detection (LOD) of glycopeptide detection was 30 attomole injection, and quantitative dynamic range spanned 4 orders magnitude. Therefore, both quantification of glycopeptides and assignment of their glycan structures were achieved by a simple analysis procedure. We assessed the utility of this method for characterizing site-specific N-glycan microheterogeneity on therapeutic antibodies, including validation of lot-to-lot glycoform variability. A significant change in the degree of terminal galactosylation was observed in different production lots of trastuzumab and bevacizumab. Cetuximab Fab glycosylation, previously known to cause anaphylaxis, was also analyzed, and several causative antigens including Lewis X motifs were quantitatively detected. The data suggests that energy-resolved oxonium ion monitoring could fulfill the regulatory requirement on the routine quality control analysis of forthcoming biosimilar therapeutics.

Proteomic characterization of ovarian cancers identifying annexin-A4, phosphoserine aminotransferase, cellular retinoic acid-binding protein 2, and serpin B5 as histology-specific biomarkers

Numerous studies have suggested that the different histological subtypes of ovarian carcinoma (i.e. clear cell, endometrioid, mucinous, and serous) have distinct clinical histories and characteristics; however, most studies that have aimed to determine biomarker have not performed comprehensive analyses based on subtype specificity. In the present study, we performed two-dimensional gel electrophoresis-based differential proteomic analysis of the different histological subtypes of ovarian carcinoma using tissue specimens from 39 patients. Seventy-seven protein spots (55 unique proteins) were found to be up- or downregulated in a subtype-specific manner. The most significant difference was observed for: (i) annexin-A4 (ANXA4) and phosphoserine aminotransferase (PSAT1), which are expressed strongly in clear cell carcinoma; (ii) cellular retinoic acid-binding protein 2 (CRABP2), which is expressed specifically in serous carcinoma; and (iii) serpin B5 (SPB5), which is upregulated in mucinous carcinoma. Validation of these candidates by western blotting using a 34 additional test sample set resulted in an expression pattern that was consistent with the screening and revealed that differential expression was independent of cancer stage or tumor grade within each subtype. Thus, the present study reinforces the notion that ovarian cancer subtypes can be clearly delineated on a molecular basis into four histopathological groups, and we propose that ANXA4, PSAT1, CRABP2, and SPB5 are candidate subtype-specific biomarkers that can help define the basis of tumor histology at a molecular level.

Direct antigen detection from immunoprecipitated beads using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry; a new method for immunobeads-mass spectrometry (iMS)

One-step detection of biological molecules is one of the principal techniques for clinical diagnosis, and the potential of mass spectrometry for biomarker detection has been a promising new approach in the field of medical sciences. We demonstrate here a new and high-sensitivity method that we termed immunobeads-mass spectrometry (iMS), which combines conventional immunoprecipitation and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The key feature of iMS is the MS-compatible condition of immunoprecipitation using detergents with a monosaccaride-C8 alkyl chain or a disaccharide-C10 alkyl chain, and the minimized number of steps required for high-sensitivity detection of target peptides in serum or biological fluid. This was achieved by optimizing the wash buffer and subjecting the immunobeads directly to MALDI-TOF MS analysis. Using this method, we showed that 1 fmol of amyloid beta peptide spiked in serum was readily detectable, demonstrating the powerful tool of iMS as a biomarker detection method.

A comprehensive peptidome profiling technology for the identification of early detection biomarkers for lung adenocarcinoma

The mass spectrometry-based peptidomics approaches have proven its usefulness in several areas such as the discovery of physiologically active peptides or biomarker candidates derived from various biological fluids including blood and cerebrospinal fluid. However, to identify biomarkers that are reproducible and clinically applicable, development of a novel technology, which enables rapid, sensitive, and quantitative analysis using hundreds of clinical specimens, has been eagerly awaited. Here we report an integrative peptidomic approach for identification of lung cancer-specific serum peptide biomarkers. It is based on the one-step effective enrichment of peptidome fractions (molecular weight of 1,000–5,000) with size exclusion chromatography in combination with the precise label-free quantification analysis of nano-LC/MS/MS data set using Expressionist proteome server platform. We applied this method to 92 serum samples well-managed with our SOP (standard operating procedure) (30 healthy controls and 62 lung adenocarcinoma patients), and quantitatively assessed the detected 3,537 peptide signals. Among them, 118 peptides showed significantly altered serum levels between the control and lung cancer groups (p<0.01 and fold change >5.0). Subsequently we identified peptide sequences by MS/MS analysis and further assessed the reproducibility of Expressionist-based quantification results and their diagnostic powers by MRM-based relative-quantification analysis for 96 independently prepared serum samples and found that APOA4 273–283, FIBA 5–16, and LBN 306–313 should be clinically useful biomarkers for both early detection and tumor staging of lung cancer. Our peptidome profiling technology can provide simple, high-throughput, and reliable quantification of a large number of clinical samples, which is applicable for diverse peptidome-targeting biomarker discoveries using any types of biological specimens.

Deglycosylation and label-free quantitative LC-MALDI MS applied to efficient serum biomarker discovery of lung cancer

BACKGROUND

Serum is an ideal source of biomarker discovery and proteomic profiling studies are continuously pursued on serum samples. However, serum is featured by high level of protein glycosylations that often cause ionization suppression and confound accurate quantification analysis by mass spectrometry. Here we investigated the effect of N-glycan and sialic acid removal from serum proteins on the performance of label-free quantification results.

RESULTS

Serum tryptic digests with or without deglycosylation treatment were analyzed by LC-MALDI MS and quantitatively compared on the Expressionist Refiner MS module. As a result, 345 out of 2,984 peaks (11.6%) showed the specific detection or the significantly improved intensities in deglycosylated serum samples (P < 0.01). We then applied this deglycosylation-based sample preparation to the identification of lung cancer biomarkers. In comparison between 10 healthy controls and 20 lung cancer patients, 40 peptides were identified to be differentially presented (P < 0.01). Their quantitative accuracies were further verified by multiple reaction monitoring. The result showed that deglycosylation was needed for the identification of some unique candidates, including previously unreported O-linked glycopeptide of complement component C9.

CONCLUSIONS

We demonstrated here that sample deglycosylation improves the quantitative performance of shotgun proteomics, which can be effectively applied to any samples with high glycoprotein contents.

Abstract 4569: Serum proteome analysis by label-free quantification system and LC-MALDI mass spectrometry for the discovery of novel biomarkers for lung cancer

Lung cancer is the leading cause of cancer death in Japan and throughout the world, and highly specific and sensitive serum biomarkers applicable for screening are urgently required. Here we report our label-free quantification study conducted on the serum samples from 10 healthy volunteers, 10 patients at early stages and 10 patients at advanced stages of lung adenocarcinoma, aiming to identify serum proteins that can be used as lung cancer biomarkers.

The workflow was divided into four sections: 1) serum sample preparations involving immunodepletion of 14 high-abundance proteins, enzymatic deglycosylation in H218O, trypsin digestion and nano-reversed phase liquid chromatography; 2) acquisition of matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) data from 30 cases; 3) label-free quantification and statistical analysis using Genedata Expressionist® platform; and 4) candidate biomarker protein identification by retrospective MS/MS acquisition.

Deglycosylation was the critical step in the sample preparation phase as it could reduce spectral complexity caused by the presence of glycopeptides with heterogeneous glycan structures. Here we utilized H218O to incorporate 18O into aspartic acid residues that occurred during the deglycosylation reaction, and thus the deglycosylation sites resulted in the specific +3 Da mass shift allowing unambiguous determination of deglycosylated peptides and their glycosylation sites.

We have shown here that 7.5 % of the identified peptides were N-glycosylated. This high level of glycopeptide occurrence, attributable to the fact that over 90 % of proteins in serum are glycoproteins, suggests that deglycosylation process would significantly simplify the peptide composition, which is critical for in-depth mass spectrometric quantification analyses of serum samples.

As the result of label-free quantification analysis, approximately 15,000 peptide species (as peak clusters) were detected from 30 serum samples. 25 peptides were screened by one-way analysis of variance to be differentially represented among the three sample groups (normal, early and advanced lung cancer cases, p &lt; 0.01). 16 peptides were specifically detected in normal serum and 9 showed increased levels in advanced stage cases, of which 2 were also detected at higher levels in early-stage cases than normal sera (p &lt; 0.05). These peptides were subjected to MS/MS acquisition, referring back to the original data to select maximally detectable spot on the archived MALDI target plate for increased chance of identification.

In conclusion, the combination of H218O deglycosylation, MALDI MS and label-free quantification can work effectively for precise quantification of glycoprotein-rich clinical specimens, allowing for the screening of serum biomarkers for cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4569.

A novel method for analyzing formalin-fixed paraffin embedded (FFPE) tissue sections by mass spectrometry imaging

Significant advances have been made in the past decade in the field of mass spectrometry imaging (MS imaging). It is a relatively unestablished technique aimed at direct, high-sensitive and spatially exclusive detection of biological molecules from the surface of tissue sections, so that semi-quantitative distribution map of the analyte can be reconstituted from the mass spectra obtained. There is tremendous potential in its application especially in clinical field, such as biomarker discovery or pharmacokinetic study. However, vast majority of the work has been performed on frozen tissue sections, while it remains generally unpractical to produce frozen sections with clinically resected tumor samples. Here we report our novel sample preparation technique that enabled MS imaging from formalin-fixed paraffin embedded (FFPE) tissue section, including retrospective archive as old as 11 years. FFPE sections were first dewaxed with pre-warmed xylene, and exposed tissue surface was enzymatically digested in nanoliter scale droplets to retain analyte localization. As a result, we succeeded in obtaining MS images of peptide peaks derived from several proteins, identified by MS/MS analysis, using ovarian cancer FFPE sections. The qualities of mass spectra obtained by this method were not significantly different from those obtained from frozen sections. By this, we opened the door to retrospective study of past clinical cases in aim to discover molecular biomarker.

Hydrogen peroxide increases interleukin-12 p40/p70 molecular ratio and induces Th2-predominant responses in mice

To investigate the influence of oxidative stress on the immune response, mice were injected with H(2)O(2), and peritoneal macrophages were isolated and stimulated in vitro with lipopolysaccharide (LPS). H(2)O(2) significantly augmented both interleukin (IL)-12p40 and IL-12p70 production and increased the p40/p70 molecular ratio. This was confirmed by mRNA analysis, which showed that H(2)O(2) increased LPS-induced mRNA expression of both IL-12p40 and IL-12p35 subunits with an increased p40/p35 ratio. Analysis of anti-ovalbumin (OVA) antibodies revealed that H(2)O(2) injection significantly increased the production of type 2 helper T cell (Th2)-associated antibody classes [immunoglobulin (Ig)E and IgG1] but not a Th1-associated antibody class (IgG2a). To confirm the Th2-predominant immune response, we analyzed the profile of cytokine production by spleen T cells of OVA-immunized and H(2)O(2)-injected mice. H(2)O(2) significantly increased the production of IL-4 but not that of interferon-gamma. Together, these results suggest that H(2)O(2)-induced overproduction of IL-12p40 promotes the Th2-predominant response through increased production of IL-12p40-homodimers, which could serve as an antagonist of the Th1-inducing cytokine IL-12p70.

Social images of medicine and dentistry in Japan. An exploratory study using correspondence analysis

OBJECTIVE

To investigate social images associated with dentistry in comparison with nine other medical disciplines.

DESIGN

A questionnaire survey among members of the general public. Subjects were asked to state, in not more than five words, the images which they associated with each of the ten disciplines.

SETTING

Komaki City, Shikatsu Town and Nagoya City in Japan.

PARTICIPANTS

261 respondents from a convenience sample of 300 residents, not associated with any branch of medicine.

OUTCOME MEASURES

Frequency distribution of word images used on at least five occasions and a correspondence analysis of the responses for the ten disciplines.

RESULTS

Of the 163 coded image items, 60 were related to internal medicine, 56 to dentistry, 55 to dermatology, 51 to orthopaedic surgery, 51 to ophthalmology, 50 to surgery, 47 to obstetrics and gynaecology, 43 to otolaryngology, 40 to paediatrics and 33 to psychiatry. Correspondence analysis applied to the 163 items and 10 medical disciplines indicated that three similar paired image groups were found, namely between dermatology and ophthalmology, surgery and orthopaedic surgery, and between dentistry and internal medicine, which were the more commonly encountered disciplines across all age groups. However, compared with the other specialities, dentistry had a significantly greater association with pain, this response being four times more common than for surgery.

CONCLUSIONS

This group of members of the public in Japan perceived dentistry-associated images in a similar way to internal medicine, but the negative associations with pain need to be addressed by the dental profession and health educators alike.

[An elderly case with impending myocardial infarction of endoventricular circular patch plasty with coronary artery bypass grafting]

An 81-year-old man with anterior impending re-myocardial infarction was urgently operated. Preoperative ECG and UCG examinations showed old myocardial infarction and LV aneurysm, respectively. We chose the Dor method (endoventricular circular patch plasty) and CABG aiming at early recovery from congestive heart failure. He fell into respiratory failure temporarily, but otherwise, the clinical course of this operation was good. He was discharged 47 days after the operation on foot. The Dor method combined with CABG is excellent way to relieve patients from congestive heart failure with LV aneurysm.

Surgical repair of a concealed aortocaval fistula associated with an abdominal aortic aneurysm: report of two cases

Two cases of a concealed aortocaval fistula (ACF) associated with an abdominal aortic aneurysm (AAA) are presented herein. ACF is a rare complication of AAA and only a few cases have so far shown the triad of symptoms, including congestive heart failure, a continuous abdominal bruit, and a pulsating abdominal mass. Sometimes a definite diagnosis is not made preoperatively and as a result, massive bleeding is encountered. We believe that the presence of a large aneurysm, compression, and involvement of the inferior vena by an aneurysm, and pelvic venous dilatation on abdominal computed tomography and hematuria may additionally suggest the presence of a concealed ACF. A correct preoperative diagnosis will help greatly in selecting the optimal surgical modality and should also reduce the degree of bleeding.

The relationship between plasma concentration of mature adrenomedullin and jugular venous oxygen saturation during and after cardiopulmonary bypass

Adrenomedullin (AM), a vasodilatory peptide, increases during cardiac surgery. However, the physiological role of AM during cardiac surgery remains unclear. AM dilates cerebral arterioles and increases cerebral blood flow in rats. Therefore, we investigated whether AM is related to cerebral oxygen balance during cardiac surgery. In nine patients undergoing coronary artery bypass grafts, plasma concentrations of mature AM from the radial artery (mAMa) and jugular bulb (mAMj) were measured, and jugular venous oxygen saturation was obtained before surgery (baseline), before aortic cross-clamp (preclamp), after aortic declamp (postclamp), and 20 min after weaning from the cardiopulmonary bypass (post-CPB). Plasma concentrations of mAMa and mAMj were significantly increased at postclamp (P < 0.01 for both) and post-CPB (P < 0.01 for both) compared with baseline values. SjO(2) correlated with plasma mAMj concentrations at preclamp (r = 0.79, P < 0.01), postclamp (r = 0.71, P < 0.05), and post-CPB (r = 0.72, P < 0.05), as well as with mAMa concentrations at preclamp (r = 0.79, P < 0.01) and postclamp (r = 0.72, P < 0.05). This suggests a relationship between AM and cerebral oxygen balance during cardiac surgery.

IMPLICATIONS

Plasma concentrations of mature-form adrenomedullin, a vasodilatory peptide, was correlated with jugular venous oxygen saturation during cardiac surgery. This suggests a relationship between adrenomedullin and cerebral oxygen balance during cardiac surgery.

Fluoride concentrations at and near the neonatal line in human deciduous tooth enamel obtained from a naturally fluoridated and a non-fluoridated area

This study sought to obtain a precise profile of fluoride concentrations at and near the neonatal line in deciduous incisors and canines from the naturally fluoridated area (1.0--1.3 parts/10(6) F in drinking water) of West Hartlepool and the non-fluoridated area (less than 0.1 parts/10(6) F in drinking water) of Leeds in England. An abrasive microsampling method was used to determine the distribution of fluoride and phosphorus concentrations. The profile of fluoride concentrations in 100-microm layers before and after the neonatal line, that is, in the prenatal and postnatal enamel, were significantly higher in teeth from the fluoridated than non-fluoridated areas. It was concluded that the fact that the fluoride concentrations were about the same prenatally and postnatally in deciduous enamel obtained from the fluoridated and non-fluoridated areas indicates that fluoride enters the prenatal deciduous enamel and that it is transferred through the placenta.

Fluoride and magnesium concentrations in human dental calculus obtained from Japanese and Chinese patients

Calculus deposited on a total of 68 permanent teeth from patients 30-60 years old from Nagoya in Japan and Beijing in China was investigated. An abrasive microsampling method was used to examine the fluoride (F) and magnesium (Mg) distribution, using a fluoride ion-specific electrode and atomic absorption spectrophotometry, respectively. F concentrations decreased from the surface towards the interior of the calculus. Mg concentrations, however, gradually rose towards the innermost surface adjacent to the tooth. In all parts of the depth profiles, the average concentrations of both magnesium and fluoride were higher in the Japanese than in the Chinese calculus. Towards the inner surface of the calculus, F and Mg concentrations were also much higher in the Japanese than in the Chinese group. A greater intake of sea foods and greater use of fluoride dentifrices are possible reasons for the higher F and Mg concentrations in the Japanese individuals.

[An oral health scoring system for promoting 8020 achievement in residents]

The present study was undertaken to develop a self-scoring system which can be used by a resident to check lifestyle. The oral health scoring system which we used in Tobishima village, Aichi-ken, was named SAWAYAKA score. A total of 777 subjects were examined. The subjects responded to a questionnaire regarding their past individual lifestyles and dietary habits. Oral health conditions were also examined by dentists. The odds ratio and 95% confidence interval were calculated both from retained tooth numbers and the questionnaire. Questions with significant odds ratio were selected and the partial regression coefficients of quantification II method by Hayashi were calculated. The results are as follows; 1) Eleven questions showed a significant odds ratio between retained tooth numbers and past lifestyle and dietary habits. The questions involved the frequency of snack intake, tooth brushing frequency, having own tooth brush, smoking, drinking, having a hobby, having a family dentist, consulting a dentist before a problem got serious, gum bleeding, swollen gums and toothache caused by sensitivity to cold water. 2) The eleven items were analysed by using Hayashi's quantification II method. 3) The results showed that unswollen gums affected the retention of teeth by the range of 1.240. Toothache caused by sensitivity to cold water affected the retention of teeth by the range of 0.765. Having a hobby affected the retention of teeth by the range of 0.691. 4) The "SAWAYAKA" score was used to select important items, excluding drinking. 5) When results were analysed with the SAWAYAKA score, an average of 9.6 was obtained. It was concluded that the scoring list could be used for checking resident's lifestyles, and for promoting the preservation of more than 20 teeth at the age of 80.

Fluoride profiles in dental plaque in vivo formed on fluoride pre-treated human enamel

Using a novel device capable of generating plaque in vivo on a natural enamel substrate, it has been possible to determine fluoride profiles from the saliva-plaque interface towards the enamel surface. Fluoride profiles in dental plaques tended to fall from the saliva-plaque interface towards the enamel. The device also offered the possibility of examining fluoride distributions after pre-treatment of the enamel with fluoride in vitro. Fluoride profiles were determined in plaque generated in vivo on enamel surfaces, which had been previously treated with a 900-ppm fluoride solution. The results showed the previously reported fall from the plaque surface, but in addition, a further rise towards the enamel surface was seen. The data imply that enamel loaded with fluoride can release some of this fluoride back into the plaque and may act as a fluoride reservoir.

Antibacterial properties of AM-1155, a new 8-methoxy quinolone

AM-1155 is a new 8-methoxy quinolonecarboxylic acid with a broad spectrum of antibacterial activity. It inhibited more than 90% of clinical isolates of methicillin-susceptible Staphylococcus aureus, streptococci, Enterococcus faecalis, most of the Enterobacteriaceae, Acinetobacter calcoaceticus and Haemophilus influenzae at the concentration of 0.39 mg/L. AM-1155 was 2- to 16-fold more active than ciprofloxacin against Gram-positive organisms including methicillin-resistant staphylococci. The antibacterial activity of AM-1155 was almost equal to that of sparfloxacin against a wide range of Gram-positive and Gram-negative species. AM-1155 also showed a good activity against anaerobes. The protective efficacy of AM-1155 against experimental systemic infections with Gram-positive and Gram-negative pathogens in mice was almost equal or superior to that of sparfloxacin. AM-1155 was 5- to 28-times more effective than ciprofloxacin, in terms of ED50 at one week, in staphylococcal and streptococcal infections.

[Intermittent mini-dose vancomycin intravenous administration and closed continuous irrigation technique applied to mediastinitis caused by MRSA following mitral valve replacement]

Mediastinitis caused by MRSA (Methicillin-Resistant Staphylococcus aureus) remains an intractable infection producing high mortality even in these days of advanced chemotherapy. The authors report a case of mediastinitis due to MRSA complicated with acute renal failure following mitral valve replacement. The patient's mediastinum had been thoroughly cleaned with physiological saline solution with 0.2% povidone iodine, and underwent a chemotherapy regimen of mini-dose vancomycin. The patient made favorable progress and recovered completely. Our patient's progress confirmed that when chemotherapy using vancomycin is administered in a patient whose condition is complicated with acute renal failure, closely monitoring the vancomycin serum concentration is essential. Intermittent mini-dose intravenous administration is sufficient to maintain an effective vancomycin serum concentration. In our case, vancomycin serum concentration measured before and at completion of dialysis revealed no appreciable decline.

[Reoperations on valvular disease: an analysis of outcome]

To evaluate risks and complications of reoperation on valvular disease, we reviewed data on 186 patients who underwent reoperations because of prosthetic valve malfunctions, pregression of valvular disease after open mitral commissulotomy and previous valvular replacement. Overall hospital mortality was 4.8% (9/186 patients). The common causes of death was low cardiac output syndrome (3 pts.) and respiratory failure (3 pts.) and others (3 pts). Hospital mortality was different according to the risk factors. There was no significant difference between the operative procedures; AVR (6.2%), MVR (3.2%), DVR (8%), TVR (0%) and MVR + TVR (9%). Furthermore, advanced age, valve position, renal failure, preoperative %FS, LVDd and diagnosis of prosthetic valve malfunction did not appear to be significant risk factor. However, preoperative respiratory failure and emergency operation showed significant increase of hospital mortality in comparison with other factors. On the basis of this reports, hospital mortality and late survival indicated that reoperation should be performed early as the potentially safe condition.

[Efficacy of myocardial preservation using HTK solution in continuous 120 min cross-clamping method--a comparative study with GIK method]

The aim of this study is to investigate the efficacy of HTK solution in the 120 minutes cross-clamping method in comparison with conventional intermittent cardioplegia using GIK solution. Fifty-four open heart surgery were performed with cardioplegic solution using either HTK solution (HTK) or GIK solution (GIK). In the HTK, HTK (3L) was infused for the initial dose and 1L was added every 60 min after 120 min of cross-clamping. In GIK, 1L of GIK solution was intermittently infused initially and then every 30 min together with continuous cold blood perfusion. The effect of two cardioplegic solution was evaluated by postoperative cardiac function (CI, %SF), released enzymes (CPK), histology and dosage of catecholamine. Postoperative CI was 3.67 +/- 0.76 in HTK, and 4.34 +/- 1.04 in GIK (NS). % SF was 26.0 +/- 5.26 in HTK and 25.6 +/- 0.76 in HTK, and 4.34 +/- 1.04 in GIK (NS). %SF was 26.0 +/- 5.26 in HTK and 25.6 +/- 9.2 in GIK (NS). The CK-MB (IU/dl) level after reperfusion was significantly decreased in HTK at 60 and 180 min after reperfusion. Histology at 60 min of ischemia revealed a significant increase of edema of mitochondria in GIK. Postoperative catecholamine dose was 2.65 +/- 1.3 in HTK and 10.3 +/- 3.4 in GIK (p < -0.01). PH of myocardium was well maintained around 7.4 during cross-clamping in HTK, however, it was decreased in GIK. In conclusion, The HTK method offers a reliable cardiac protection due to effective buffering using Histidine in comparison with GIK.

Postcolumn fluorometric detection system for liquid chromatographic analysis of amino and imino acids using o-phthalaldehyde/N-acetyl-L-cysteine reagent

A high-performance liquid chromatographic system for the determination of amino acid and imino acid was developed using a two-step reaction with sodium hypochlorite and o-phthalaldehyde/N-acetyl-L-cysteine (OPTA/AcCys) reagent. This reagent improved the sensitivity in the analysis of proline presumably because the fluorophore is more stable to hypochlorite which has been used for the oxidative cleavage of the imino linkage. The use of OPTA/AcCys facilitated the detection of imino acids at the same concentration level as that of amino acids. The detection limit for all the amino and imino acids was a few picomoles. This detection system, together with cation-exchange chromatographic separation, was applied to the determination of amino and imino acids in biological samples.