Reversible renal-limited thrombotic microangiopathy due to gemcitabine-dexamethasone-cisplatin therapy: a case report.

BACKGROUND: Gemcitabine and cisplatin are chemotherapeutic agents used for treating multiple cancers, and these agents are sometimes used in combination. Drug-induced thrombotic microangiopathy (TMA) is a rare but potentially fatal complication. It typically presents as a systemic disease with the classical triad of hemolytic anemia, thrombocytopenia, and organ damage. In contrast to systemic TMA, cases of renal-limited TMA, defined as biopsy-proven renal TMA without the classical triad, have been reported with relatively good prognosis. Most cases of renal-limited TMA are associated with calcineurin inhibitors, and cases of drug-induced renal-limited TMA due to gemcitabine-dexamethasone-cisplatin therapy have been rarely reported. CASE PRESENTATION: A 43-year-old woman with lymphoma developed acute kidney injury with marked proteinuria, microhematuria, and abnormal urinary casts after receiving one cycle of gemcitabine-dexamethasone-cisplatin therapy. Although she did not show hemolytic anemia and thrombocytopenia, renal biopsy showed diffuse injury to the glomerular endothelial cells, supporting the diagnosis of renal-limited TMA. Her condition improved only with the cessation of gemcitabine and cisplatin treatment. She received another chemotherapy without gemcitabine and platinum agents, and no recurrence of renal-limited TMA was observed. CONCLUSIONS: Drug-induced TMA occurs early after gemcitabine and cisplatin use in renal-limited form and is reversible when detected and managed in a timely manner. Urinalysis, which is simple and inexpensive and can be easily performed, is a beneficial screening tool for early-onset drug-induced TMA among patients who receive gemcitabine-dexamethasone-cisplatin therapy.

Cholera toxin B induces interleukin-1ß production from resident peritoneal macrophages through the pyrin inflammasome as well as the NLRP3 inflammasome.

Cholera toxin B (CTB) is a subunit of cholera toxin, a bacterial enterotoxin secreted by Vibrio cholerae and also functions as an immune adjuvant. However, it remains unclear how CTB activates immune cells. We here evaluated whether or how CTB induces production of a pro-inflammatory cytokine, interleukin-1ß (IL-1ß). CTB induced IL-1ß production not only from bone marrow-derived macrophages (BMMs) but also from resident peritoneal macrophages in synergy with O111:B4-derived lipopolysaccharide (LPS O111:B4) that can bind to CTB. Meanwhile, when prestimulated with O55:B5-derived LPS (LPS O55:B5) that fails to bind to CTB, resident peritoneal macrophages, but not BMMs, produced IL-1ß in response to CTB. The CTB-induced IL-1ß production in synergy with LPS in both peritoneal macrophages and BMMs was dependent on ganglioside GM1, which is required for internalization of CTB. Notably, not only the NLRP3 inflammasome but also the pyrin inflammasome were involved in CTB-induced IL-1ß production from resident peritoneal macrophages, while only the NLRP3 inflammasome was involved in that from BMMs. In response to CTB, a Rho family small GTPase, RhoA, which activates pyrin inflammasome upon various kinds of biochemical modification, increased its phosphorylation at serine-188 in a GM1-dependent manner. This phosphorylation as well as CTB-induced IL-1ß productions were dependent on protein kinase A (PKA), indicating critical involvement of PKA-dependent RhoA phosphorylation in CTB-induced IL-1ß production. Taken together, these results suggest that CTB, incorporated through GM1, can activate resident peritoneal macrophages to produce IL-1ß in synergy with LPS through novel mechanisms in which pyrin as well as NLRP3 inflammasomes are involved.

Maxillary Hypoplasia With Congenital Oligodontia Treated by Maxillary Distraction Osteogenesis.

It is known that congenitally missing teeth can often cause differences in craniofacial morphology; however, there are few reported cases of orthognathic surgical treatment for these patients. Herein, the authors report a rare case of maxillary hypoplasia with congenital oligodontia treated by maxillary distraction osteogenesis with internal device. A 17-year-old male presenting with multiple tooth agenesis and maxillary recession was referred to our hospital for orthognathic surgical treatment. Preoperative simulation surgery was performed using Full-Color 3-dimensional salt model. After surgery, improvement in maxillary recession and occlusal stability was observed. This report demonstrates the advantages of the method used herein, which includes reduction in operating time with increase in the safety of the procedure.

Aged Garlic Extract Suppresses the Development of Atherosclerosis in Apolipoprotein E-Knockout Mice.

BACKGROUND: Aged garlic extract (AGE) has been shown to retard the progression of coronary calcification in patients with coronary artery disease. OBJECTIVE: To clarify the mechanism of AGE's action to retard atherosclerosis, we investigated whether AGE suppresses the formation and progression of atherosclerosis in Apolipoprotein E (Apoe)-knockout (ApoE-KO) mice. METHODS: Male C57BL/6J mice (control mice, 5 wk old) were fed a standard diet, whereas male ApoE-KO mice (5 wk old) were fed a standard diet with or without 3% AGE for 12 or 24 wk. After the treatment, blood samples, aortas, and spleens were collected from all mice. Concentrations of total cholesterol (TC), HDL cholesterol, and triglycerides (TGs) in serum were measured. The area of atherosclerotic lesion in the aorta was examined by Oil Red O staining. The relative abundances of monocytes plus macrophages (CD11b(+) cells) and interferon-γ-producing CD4(+) T cells in spleen were assessed by flow cytometric analysis. RESULTS: The atherosclerotic lesion areas in the aortas of ApoE-KO mice were 87 and 114 times as great (P < 0.01) as those in control mice at 12 and 24 wk, respectively. AGE feeding significantly inhibited the progression of atherosclerotic lesion area in ApoE-KO mice by 22% (P < 0.05) at 12 wk. In addition, serum concentrations of TC and TGs in ApoE-KO mice were significantly higher than those in control mice at 12 and 24 wk. Treatment with AGE significantly suppressed the increases in serum concentrations of TC and TGs in ApoE-KO mice by 21% (P < 0.05) and 19% (P < 0.05) at 24 wk, respectively, and reduced the relative abundance of CD11b(+) cells in ApoE-KO mice by 24% (P < 0.05) at 12 wk. CONCLUSION: These data suggest that the antiatherosclerotic activity of AGE is at least partly due to the suppression of inflammation and lipid deposition in the vessels during the early stage of atherosclerotic development in ApoE-KO mice.

Spatial correlativity of atmospheric particulate components simultaneously collected in Japan.

The simultaneous sampling of total suspended particles was performed at 14 sites in Japan during July 2008-June 2009. The spatial correlativity of each particulate composition toward Osaka was obtained for nine selected sites to overview the chemical composition and geographical distribution of particulate components across a wide range of areas nationwide. The spatial correlatives of atmospheric particulate components were extended to an even wider range of areas up to 950 km distance (meso-alpha scale region, >200 km) for a far-reaching distance analysis unique in the literature. Overall, the spatial correlations of ionic species and both organic and elemental carbons were significant, suggesting their shared advections, including their long-range transport from East Asia. Although sulfate ions are widely dispersed across Japan, such is not necessarily correlated with organic and elemental carbon, possibly indicating that the sulfate emission source, including long-range transport, differs from that of carbonaceous particulates. By contrast, the characteristics of spatial correlatives of metallic constituents vary; for example, particulate Pb and Cd show a significantly wide range of spatial correlatives to Osaka, while Mn-though limited to cities neighboring Osaka-shows significant spatial correlations. Other metallic constituents showed no significant spatial correlatives, indicating the effects of local pollutants. Moreover, the extent of the spatial dispersion of the particulate components and the relationships among chemical components were analyzed via factor analysis to highlight the effects of long-range inflow and local original emissions. In this treatment, 13 particulate components among the 19 measured were implicated in long-range transport.

Safety and outcomes of surgical treatment of atrial fibrillation in emergency surgery cases.

BACKGROUND: Recent developments in surgical devices, including left atrial appendage closure, have enabled surgeons to perform aggressive operations for atrial fibrillation (AF). However, the outcomes of AF surgery in emergent cases have not been extensively studied. OBJECTIVE AND METHODS: The present study aimed to investigate the effectiveness of AF surgery in emergency surgery cases associated with cardiovascular events. We enrolled 18 patients who underwent various types of AF surgery due to emergencies, including acute aortic dissection (n = 6), acute myocardial infarction (n = 5), bleeding due to perforation from radiofrequency catheter ablation (n = 4), acute mitral regurgitation (n = 2), and cardiac tumor (n = 1). Four and ten patients underwent the full maze procedure and pulmonary vein isolation, respectively. Ganglionated plexi ablation was also performed in three patients as part of a combined procedure. The left atrial appendage was solely closed in four patients. RESULTS: There was no surgical mortality or major adverse cardiac and cerebrovascular events in our patient series. The rates of freedom of recurrence of AF or atrial tachycardia at 1 and 3 years were 92.9% and 82.5%, respectively. After a mean follow-up period of 46.7 ± 25.8 months, no thromboembolism events were observed in the patients. Furthermore, no cardiovascular death was recorded. CONCLUSION: The surgical procedures for AF are safe and effective in cases requiring emergency surgery.

Life-Threatening Conditions and Preoperative Complications Associated with Cardiac Neoplasm Do Not Affect Surgical Outcomes or Mortality.

Background: Cardiac neoplasms may cause life-threatening symptoms associated with cerebral infarction, ventricular arrhythmias, and heart failure. Emergency surgery or preoperative treatment may be required for these patients. However, no study has reported the surgical outcomes in cases involving cardiac neoplasms with life-threatening complications. The current study investigated the mid- to long-term outcomes of surgery in patients with cardiac neoplasms in life-threatening conditions. Methods: This study retrospectively analyzed 36 consecutive patients who underwent resection for cardiac neoplasms with life-threatening cardiovascular, respiratory, and cerebral nervous system complications from January 2000 to December 2022. Their mean age at surgery was 54.9 years. In terms of fatal events, one patient who experienced a ventricular tachycardia storm caused by a left ventricular neoplasm was placed under deep sedation and managed with a ventilator preoperatively. Seven patients who presented with limb motor paralysis and visual defects had cerebral infarction. Two of the seven patients with cerebral infarction received cerebrovascular treatment before cardiac surgery. Results: During the follow-up period, cerebral- and cardiovascular-related deaths were not recorded. All postoperative cerebral and cardiovascular complications were new-onset cerebral infarction (n = 2) (with symptoms that improved during the long term). The mean follow-up period was 6.2 years. The 5- and 10-year survival rates of all patients were 89.8% and 78.7%, respectively. There were no significant differences in postoperative prognosis between patients with preoperative cerebral infarctions and those without. Conclusions: The long-term surgical outcome of patients with life-threatening symptomatic cardiac neoplasm was good. Thus, preoperative complications did not affect prognosis.

Fluorophotometric determination of histone with 3,4,5,6-tetrafluoro-2-carboxyphenylfluorone-manganese(II) complex and its characterization.

A simple fluorophotometric method for the determination of histone has been developed. This method involves a fluorescence quenching reaction that results in the formation of a complex of manganese(II), 3,4,5,6-tetrafluoro-2-carboxyphenylfluorone (TFCPF), and histone in a non-ionic surfactant micellar medium. The calibration curve was found to be linear in the range of 0.5 to 2.0 µg/mL. The binding parameters (n, number of binding sites; K, binding constant) and thermodynamic parameters (ΔG(0), change in Gibbs free energy; ΔH(0), change in enthalpy; ΔS(0), change in entropy) were investigated spectrophotometrically for the elucidation of the reaction mechanism. The resulting binding parameters (n=4.08 and K=3.16×10(4) m(-1) at 25°C) and thermodynamic parameters (ΔG=-25.83 kJ/mol, ΔH=-9.83 kJ/mol, and ΔS=53.68 J/(mol K)) suggest that the colored complex in this reaction system is an ion-association complex between manganese(II)-TFCPF and histone.

Case of left ventricular thrombus managed with thrombectomy with left ventricular reconstruction in a patient who had coronavirus disease 2019 infection.

BACKGROUND: Intracardiac thrombus is relatively rare in patients with coronavirus disease 2019 (COVID-19). However, if it occurs, thrombotic complications are likely to develop. In this case, we performed a successful thrombectomy on a patient who developed left ventricular thrombus after COVID-19 infection without complications. CASE PRESENTATION: A 52-year-old man sought medical care due to fever, dyspnea, and abnormalities in the taste and smell that persisted for 2 weeks. The patient was diagnosed with COVID-19 and was treated with remdesivir, baricitinib, and heparin. Three weeks after hospitalization, electrocardiogram revealed angina pectoris, and cardiac catherization showed left anterior descending coronary artery stenosis. In addition, global hypokinesis and a thrombus at the left ventricular apex were observed on echocardiography. Left ventricular reconstruction concomitant with coronary artery bypass grafting was performed. A thrombus in the left ventricle was resected via left apical ventriculotomy, and the bovine pericardium was covered and sutured on the infarction site to exclude it. The patient was extubated a day after surgery and was transferred to another hospital for recuperation after 20 days. He did not present with complications. CONCLUSIONS: Thrombotic events could be prevented via thrombectomy with left ventricular reconstruction using an intraventricular patch to exclude the residual thrombus.

A Case of Contained Rupture of the Common Iliac Artery with Idiopathic Retroperitoneal Fibrosis: Efficacy of Surgical Treatment and Immunosuppressive Therapy at 2-Year Follow-Up.

Rupture of inflammatory aortic aneurysm associated with retroperitoneal fibrosis (RF) is rare. We report a 62-year-old man with an inflammatory abdominal aortic aneurysm (IAAA) complicated with idiopathic RF, resulting in a contained rupture of the common iliac artery. The patient also presented with mild renal insufficiency due to urethral obstruction and left hydronephrosis. Surgical procedures including graft replacement and ureterolysis relieved the symptoms. Postoperative immunosuppressive treatment using corticosteroid and methotrexate successfully maintained clinical remission without signs of recurrence of RF and IAAA at the 2-year follow-up.

Appetite loss and associated factors at 1 year after intensive care unit elder survivors in a secondary analysis of the SMAP-HoPe study.

Appetite loss, a common but serious issue in older patients, is an independent risk factor for sarcopenia, which is associated with high mortality. However, few studies have explored the phenomenon of appetite loss after discharge from the intensive care unit (ICU). Therefore, we aimed to describe the prevalence of appetite loss and relationship between appetite loss and depression in patients living at home 12 months after intensive care. This study involved secondary analysis of data obtained from a published ambidirectional study examining post-intensive care syndrome 12 months after discharge (SMAP-HoPe study) conducted in 12 ICUs in Japan. We included patients aged > 65 years. The Short Nutritional Assessment Questionnaire and Hospital Anxiety Depression Scale were used for the analysis. Descriptive statistics and a multilevel generalized linear model were used to clarify the relationship between appetite loss and depression. Data from 468 patients were analyzed. The prevalence of appetite loss was 25.4% (95% confidence interval [CI], 21.5-29.4). High severity of depression was associated with a high probability of appetite loss (odds ratio, 1.2; 95%CI, 1.14-1.28; p = 0.00). Poor appetite is common 12 months after intensive care and is associated with the severity of depression.

Combined cardiac surgery in a Marfan syndrome patient with severe scoliosis via lower hemisternotomy: a case report.

BACKGROUND: Scoliosis is one of the symptoms manifested by patients with Marfan syndrome (MFS). Deformity of the thoracic cavity due to severe scoliosis may cause difficulty during cardiac surgery in terms of the surgical approach and instrument manipulation; however, only a few reports have been available regarding the surgical case of MFS with severe scoliosis. Here, we report a case of combined aortic valve replacement and left atrial appendage closure in a patient with MFS who had severe scoliosis using lower hemisternotomy. CASE PRESENTATION: A 62-year-old female with MFS was referred to our hospital after being diagnosed with severe aortic regurgitation and paroxysmal atrial fibrillation with a history of cerebral thromboembolism. The aortic valve showed severe insufficiency due to cusp prolapse, whereas the aortic root was moderately dilated (42 mm). Echocardiography revealed severe regurgitation with reduced left ventricular ejection function (32%) and massive left ventricular diastolic dimension (88 mm). Moreover, combined aortic valve replacement and left atrial appendage closure was indicated. However, the patient had chest deformity due to severe scoliosis. Thus, conventional full sternotomy or thoracotomy was considered an inappropriate surgical approach. Lower hemisternotomy was selected on the basis of three-dimensional reconstruction imaging of the aorta, left atrial appendage, sternum, and rib. Sternal elevation and rib retraction with the costal arch folded back provided enough surgical field for the combined procedures to be safely conducted. The postoperative course was uneventful, except for predicted prolonged mechanical ventilation with the assistance of intraaortic balloon pumping. Thereafter, the patient has been free from any cardiac and cerebrovascular event. CONCLUSIONS: Lower hemisternotomy can be useful for combined cardiac surgery in MFS with severe scoliosis.

Surgical Treatment of a Giant Popliteal Venous Aneurysm and Arteriovenous Fistula on the Adjacent Femoral Vein and Its Postoperative Findings.

A case of a giant popliteal venous aneurysm that caused massive pulmonary thromboembolism with an arteriovenous fistula draining into the adjacent proximal femoral vein is reported herein. Deep veins in the lower leg were occluded by thrombi. The inlet and outlet orifice inside the aneurysm was closed and aneurysmorraphy was performed. The fistula was retained on the estimation that it would maintain the blood flow and prevent thrombus formation inside the femoral vein. The aneurysm was shrunk, the femoral vein was patent, and the fistula was not observed 1 year later, although it still existed 1 week after the operation.

Employment status and its associated factors for patients 12 months after intensive care: Secondary analysis of the SMAP-HoPe study.

BACKGROUND: Returning to work is a serious issue that affects patients who are discharged from the intensive care unit (ICU). This study aimed to clarify the employment status and the perceived household financial status of ICU patients 12 months following ICU discharge. Additionally, we evaluated whether there exists an association between depressive symptoms and subsequent unemployment status. METHODS: This study was a subgroup analysis of the published Survey of Multicenter Assessment with Postal questionnaire for Post-Intensive Care Syndrome for Home Living Patients (the SMAP-HoPe study) in Japan. Eligible patients were those who were employed before ICU admission, stayed in the ICU for at least three nights between October 2019 and July 2020, and lived at home for 12 months after discharge. We assessed the employment status, subjective cognitive functions, household financial status, Hospital Anxiety and Depression Scale, and EuroQOL-5 dimensions of physical function at 12 months following intensive care. RESULTS: This study included 328 patients, with a median age of 64 (interquartile range [IQR], 52-72) years. Of these, 79 (24%) were unemployed 12 months after ICU discharge. The number of patients who reported worsened financial status was significantly higher in the unemployed group (p<0.01) than in the employed group. Multivariable analysis showed that higher age (odds ratio [OR], 1.06; 95% confidence interval [CI], 1.03-1.08]) and greater severity of depressive symptoms (OR, 1.13 [95% CI, 1.05-1.23]) were independent factors for unemployment status at 12 months after ICU discharge. CONCLUSIONS: We found that 24.1% of our patients who had been employed prior to ICU admission were subsequently unemployed following ICU discharge and that depressive symptoms were associated with unemployment status. The government and the local municipalities should provide medical and financial support to such patients. Additionally, community and workplace support for such patients are warranted.

Spectrophotometric determination of cobalt(II) and cyanocobalamin with vanillilfluorone and its applications.

Spectrophotometric determination of cobalt(II) was accomplished with vanillilfluorone (VF) in the presence of dimethylbenzyltetradecylammonium chloride (Zephiramine, Zep). In the determination of cobalt(II), Beer's law was obeyed in the range of 24-470 ng/ml, with an effective molar absorption coefficient (at 575 nm) and relative standard deviation of 1.35×10(5) l mol(-1) cm(-1) and 0.66% (n=5), respectively. The composition ratio of the colored complex was determined by the mole ratio and continuous variation methods, and it was found to be Co(II) : VF : Zep=1 : 2 : 4. Analysis of cyanocobalamin by the same procedure showed that cyanocobalamin could be determined in the concentration range of 0.5-0.11 µg/ml using the proposed method.

Prevalence of and risk factors for post-intensive care syndrome: Multicenter study of patients living at home after treatment in 12 Japanese intensive care units, SMAP-HoPe study.

Few studies have examined the epidemiology of post-intensive care syndrome in Japan. This study investigated the mental health and quality of life of patients living at home in Japan after intensive care unit (ICU) discharge. Additionally, we examined whether unplanned admission to the ICU was associated with more severe post-traumatic stress disorder (PTSD), anxiety, and depressive symptoms. An ambidirectional cohort study was conducted at 12 ICUs in Japan. Patients who stayed in the ICU for > 3 nights and were living at home for 1 year afterward were included. One year after ICU discharge, we retrospectively screened patients and performed a mail survey on a monthly basis, including the Impact of Event Scale-Revised (IER-S), the Hospital Anxiety Depression Scale (HADS), and the EuroQOL-5 Dimension (EQ-5D-L) questionnaires. Patients' characteristics, delirium and coma status, drugs used, and ICU and hospital length of stay were assessed from medical records. Descriptive statistics and multilevel linear regression modeling were used to examine our hypothesis. Among 7,030 discharged patients, 854 patients were surveyed by mail. Of these, 778 patients responded (response rate = 91.1%). The data from 754 patients were analyzed. The median IES-R score was 3 (interquartile range [IQR] = 1‒9), and the prevalence of suspected PTSD was 6.0%. The median HADS anxiety score was 4.00 (IQR = 1.17‒6.00), and the prevalence of anxiety was 16.6%. The median HADS depression score was 5 (IQR = 2‒8), and the prevalence of depression was 28.1%. EQ-5D-L scores were lower in our participants than in the sex- and age-matched Japanese population. Unplanned admission was an independent risk factor for more severe PTSD, anxiety, and depressive symptoms. Approximately one-third of patients in the general ICU population experienced mental health issues one year after ICU discharge. Unplanned admission was an independent predictor for more severe PTSD symptoms.

A weighted q-gram method for glycan structure classification.

BACKGROUND: Glycobiology pertains to the study of carbohydrate sugar chains, or glycans, in a particular cell or organism. Many computational approaches have been proposed for analyzing these complex glycan structures, which are chains of monosaccharides. The monosaccharides are linked to one another by glycosidic bonds, which can take on a variety of comformations, thus forming branches and resulting in complex tree structures. The q-gram method is one of these recent methods used to understand glycan function based on the classification of their tree structures. This q-gram method assumes that for a certain q, different q-grams share no similarity among themselves. That is, that if two structures have completely different components, then they are completely different. However, from a biological standpoint, this is not the case. In this paper, we propose a weighted q-gram method to measure the similarity among glycans by incorporating the similarity of the geometric structures, monosaccharides and glycosidic bonds among q-grams. In contrast to the traditional q-gram method, our weighted q-gram method admits similarity among q-grams for a certain q. Thus our new kernels for glycan structure were developed and then applied in SVMs to classify glycans. RESULTS: Two glycan datasets were used to compare the weighted q-gram method and the original q-gram method. The results show that the incorporation of q-gram similarity improves the classification performance for all of the important glycan classes tested. CONCLUSION: The results in this paper indicate that similarity among q-grams obtained from geometric structure, monosaccharides and glycosidic linkage contributes to the glycan function classification. This is a big step towards the understanding of glycan function based on their complex structures.

Diaphragm disease associated with nonsteroidal anti-inflammatory drugs mimicking intestinal tumor: A case report.

INTRODUCTION: Diaphragm disease is rare and caused by intestinal obstruction due to nonsteroidal anti-inflammatory drugs (NSAIDs). Given the availability of video capsule endoscopy (VCE) and balloon enteroscopy (BE) this disease will be diagnosed more often. PRESENTATION OF CASE: A 73-year-old man was presented to our hospital for persistent nausea and vomiting. Abdominal ultrasound and computed tomography revealed small-bowel thickening, stricture in the terminal ileum, and dilation of the proximal small intestine. Differential diagnosis included ileal lymphoma and multiple ileal adenocarcinomas, and a diagnostic laparoscopy was performed. Twenty-centimeter of ileum was resected by primary ileo-ileal anastomosis. On pathological examination, fibrosis of the submucosa was identified, and erosions and numerous inflammatory cells reaching the submucosa were also identified from the specimen. DISCUSSION: The preoperative diagnosis of diaphragm disease is sometimes challenging due to its uncharacteristic symptoms; moreover, radiological findings are usually indefinite and distinctive. Currently, the main treatment for diaphragm disease is surgery. CONCLUSION: We have documented a case of intestinal obstruction by NSAIDs. However, it is desirable to determine the course of treatment based on small bowel endoscopic dilatation cases in the future.

Fluorophotometric determination of hydrogen peroxide with fluorescin in the presence of cobalt (II) and reaction against other reactive oxygen species.

A fluorophotometric method for the determination of hydrogen peroxide (H2O2) using fluorescin was developed. This method was based on the oxidative reaction of fluorescin, a colorless, non-fluorescent lactoid fluorescein, by H2O2 to give highly fluorescein fluorescence emission. In the determination of H2O2, the calibration curve exhibited linearity over the H2O2 concentration range of 1.5-310 ng mL(-1) at an emission wavelength of 525 nm with an excitation of 500 nm and with relative standard deviations (n = 6) of 2.51%, 2.48%, and 1.31% for 3.1 ng mL(-1), 30.8 ng mL(-1), and for 308 ng mL(-1) of H2O2, respectively. The detection limit for H2O2 was 1.9 ng mL(-1) six blank determinations was performed (rho = 6). This proposed method was applied to detection of other reactive oxygen species and nitrogen species (ROS/RNS) such as singlet oxygen (1O2), hydroxyl radical (*OH), peroxynitrite (ONOO-) etc., and it was possible to detect them with a high sensitivity. In addition, this proposed method was applied to the recovery tests of H2O2 in calf serum, human saliva, rain water, and wheat noodles; the results were satisfactory.

Synthesis, spectral study and crystal structure of a fluorescein derivative, p-methoxycarbonylphenyl fluorone.

Protolytic equilibria of p-methoxycarbonylphenyl fluorone (PMCPF) in aqueous solutions were studied by spectrophotometry, and the species of PMCPF were determined. We describe for the first time the X-ray structure of the proton acceptor form of PMCPF.