Difference in the risk of discrimination on psychological distress experienced by early wave infected and late wave infected COVID-19 survivors in Japan

The psychological distress experienced by coronavirus disease of 2019 (COVID-19) survivors after recovery from the illness is amplified by discrimination endured because of their infection status. However, the difference in the risk of facing discrimination and risk of experiencing psychological distress in the early and late waves of the COVID-19 pandemic remain unclear. This study aimed to investigate whether the risk of facing discrimination because of infection status was lower in the early or late waves and whether risk of discrimination on psychological distress was more serious in later, rather than earlier waves. We conducted two online surveys to collect data from survivors divided into two groups. The participants with scores of five or more on the Kessler Psychological Distress Scale were identified as having experienced psychological distress. The participants were identified as having experienced discrimination based on infection status if they had endured being blamed, some type of discrimination, or having themselves or their families maligned. The timing of infection was split into infected during early waves of the pandemic for 2021 participants and infected during later waves of the pandemic for 2022 participants. Modified Poisson regression analyses were performed using experiences of discrimination as criteria and timing of infection as predictors. Modified Poisson regression analyses were further performed using the presence of psychological distress as a criteria and experiences of discrimination and timing of infection as the criteria, in addition to interaction effect of these es. The data of 6010 participants who were infected in early waves and 5344 participants who were infected in later waves were analyzed. The risks of being blamed, some forms of discrimination, and participants and their families being maligned were significantly lower in the group who were infected in later waves than those infected in earlier waves. Experiences of discrimination were highly associated with psychological distress in those infected in later waves than those infected in earlier waves, while only being blamed showed a significant association. Risk of discrimination was found to be lower in those infected in later waves, whereas risk of discrimination on psychological distress was shown to be more serious in those infected in later waves. Therefore, we submit that it is more important to support COVID-19 survivors who face discrimination, than it is to attempt to decrease the current discriminatory climate caused by the COVID-19 pandemic.

Relationship between attitudes toward COVID-19 infection, depression and anxiety: a cross-sectional survey in Japan

BACKGROUND

Although negative attitudes are known to develop with experiences of COVID-19 infection, it remains unclear whether such attitudes contribute to depression and anxiety as sequelae of COVID-19. We aimed to investigate the relationships between attitude towards COVID-19 infection and post-COVID-19 depression and anxiety.

METHODS

A cross-sectional survey of COVID-19 recovered patients was conducted from July to September 2021 in Japan. Outcome variables, depression and anxiety were assessed using the Patient Health Questionnaire-9 and Generalized Anxiety Disorder-7); scores of 10 and above were identified as having symptoms of depression and anxiety, respectively. Exposure variables were whether participants were experiencing the following attitude strongly: threat to life due to COVID-19 infection, helplessness regarding COVID-19 infection, blaming a third party who did not restrain from going outside, blaming themselves for their COVID-19 infection, worry about spreading the infection to others, and self-stigma (Self-Stigma Scale-Short). Modified Poisson regression analyses were performed to analyze the findings.

RESULTS

A total of 6016 responses were included in the analyses. The proportion of depression was 19.88%, and anxiety was 11.47%. The threat of life due to COVID-19 infection, helplessness regarding COVID-19 infection, blaming oneself for their COVID-19 infection, and self-stigma were significantly associated with depression and anxiety after adjusting covariates. Blaming the third party who did not restrain from going outside was associated with anxiety. There was no association between the worry about spreading infection to others and depression or anxiety.

CONCLUSION

Negative attitudes, including self-stigma with the experience of COVID-19 infection, were related to depression and anxiety. Further studies confirming whether countermeasures for preventing or decreasing the negative attitude towards COVID-19 infection mitigate these symptoms are needed.

EXTRACELLULAR VESICLES AS MARKERS OF INFLAMMATION AND HYPERCOAGULABILITY DURING THE FIRST MONTH OF SARS-COV-2 INFECTION IN OUTPATIENTS AND HOSPITALIZED PATIENTS

Introduction

During SARS-CoV-2 infection, a severe hypercoagulability state is observed due to the stimulus of multiple mechanisms of hemostasis, such as coagulation, activation of platelets, endothelial cells, monocytes and neutrophils and impaired fibrinolysis. As a consequence, thrombotic complications are common in the course of COVID-19. Microvesicles (MVs) are intracellular transmitters that participate in pathological conditions, such as inflammatory and infectious processes, and are capable of triggering prothrombotic mechanisms. Since MVs release is potentially associated with COVID-19-induced coagulopathy, our aim was to identify during the course of the disease when the stimulus for MVs release occurs and whether this was associated with adverse outcomes.

Objective

We evaluated changes in the levels of MVs markers during the first month of SARS-CoV-2 infection in patients (pts) with severe disease (hospitalized in an Intensive Care Unit ‒ ICU) as compared to outpatients. We also evaluated the association between MVs markers with: inflammatory biomarkers (C-reactive protein, CRP), hypercoagulability (D-dimer) and death.

Methods

Blood samples were collected on three occasions: before the 10^th day of symptoms, in the 3^rd week of symptoms and in the 4^th week of symptoms for the quantification of the following MVs markers by flow cytometry: CD41A (platelet activation), CD162 (PSGL-1; leukocyte-platelet interaction), CD31 (endothelium-platelet interaction) and CD142 (tissue factor). Statistical tests of ANOVA with repeated measures, Mann-Whitney and regression methods were used.

Results

The population studied was 85 pts, being 25 from ICU. Mostly were men (51%), with a median age of 41 years. The concentration of MVs expressing CD31+, CD41+, CD162+ and CD142+ were persistently elevated in pts who required ICU compared to outpatients at the 3 moments studied, except for the levels of MVs-CD31+ and MVs-CD142+ that were similar between ICU and outpatients in the 4^th week of symptoms. However, despite the differences between the groups, there were no significant changes in the levels of MVs during the course of the disease within the groups. In subgroup analysis, we observed that increases in the levels of MVs-CD162+ and MVs-CD142+ in the 3^rd week of symptoms were associated with the risk of death (p=0.02 and p=0.06, respectively). We also observed that during the course of the disease an association between MVs, coagulability and inflammation was evident. In the 3rd week of symptoms, D-dimer levels were correlated with MV-CD31+ (r=0.52, p<0.0001), MV-CD162+ (r=0.35, p=0.001), MV-CD41A+ (r=0.44, p<0.0001) and MV-CD142+ (r=0.47, p<0.0001) and CRP values were correlated with MV-CD31+ (r=0.56, p=<0.0001), MV-CD162+ (r=0.48, p<0.0001), MV-CD41A+ (r= 0.41, p=0.0001), and MV-CD142+ (r=0.56, p<0.0001). By the 4^th week of symptoms, both D-dimers and CRP correlations with the above MVs remained unchanged.

Conclusion

To conclude, MVs that express antigens related to platelet activation, leukocyte-platelet interaction and endothelium-platelet interaction, as well as those related to tissue factor are released during the course of COVID-19 in pts with severe disease. After the 4^th week of symptoms, the release of these MVs was associated with signs of inflammation and hypercoagulability. Additionally, MVs that express tissue factor and leukocyte-platelet interaction antigens were particularly high among non-survivors, suggesting that these MVs may serve as markers of the risk of death. Finally, these findings suggest the participation of innate immunity and tissue factor pathways in the prognosis of COVID-19, and point towards a possible role of MVs as biomarkers of disease prognosis.

Differences in the Course of Depression and Anxiety after COVID-19 Infection between Recovered Patients with and without a Psychiatric History: A Cross-Sectional Study

BACKGROUND

This study aimed to examine the course of depression and anxiety in COVID-19 survivors with a psychiatric history compared with those without a psychiatric history.

METHODS

A web-based cross-sectional survey for COVID-19 survivors was conducted from July to September 2021. A total of 6016 COVID-19 survivors, the accuracy of whose responses was determined to be assured, were included in analyses. Exposures included psychiatric history and time since COVID-19 infection, and the main outcomes and measures included severity of depression and anxiety, as assessed using the Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7), respectively.

RESULTS

Mean severity of PHQ-9 and GAD-7 were significantly higher in participants with a psychiatric history than in those without a psychiatric history. Two-way analysis of covariance for PHQ-9 showed a significant main effect of the presence of psychiatric history and a significant interaction effect of psychiatric history × time since infection. Two-way analysis of covariance for the GAD-7 score revealed a significant main effect of the presence of psychiatric history and time since COVID-19 infection and the interaction effect of these factors.

CONCLUSIONS

The course of depression and anxiety was more severe in COVID-19 survivors with a psychiatric history than in those without a psychiatric history.

Association between working hours, work engagement, and work productivity in employees: A cross-sectional study of the Japanese Study of Health, Occupation, and Psychosocial Factors Relates Equity

OBJECTIVES

The aims of the study were to investigate the association between working hours, work engagement, and work productivity, and to examine if work engagement moderates the influence of working hours on work productivity.

METHODS

We used cross-sectional data from the Japanese occupational cohort survey, which involved 2093 employees in a manufacturing industry. Working hours were self-reported by the study participants. Work productivity was assessed with absolute presenteeism based on the scale of the validated Japanese version of World Health Organization Health and Work Performance Questionnaire (WHO-HPQ). Work engagement was assessed with the Nine-item Utrecht work Engagement Scale (UWES-9). Univariate and multivariable regression analyses were conducted to examine the association of working hours and work engagement with work productivity. We also carried out stratified multivariable regression analysis separately for those with high-work engagement and those with low-work engagement.

RESULTS

Working >40 to 50 hours per week and >50 hours per week were significantly positively associated with work productivity in univariate analysis. However, the significant association no longer held after adjusting for work engagement. Work engagement was positively associated with work productivity even after controlling for potential confounders. Working hours were not significantly associated with work productivity among those with high-work engagement or among those with low-work engagement.

CONCLUSIONS

Working hours did not have any significant associations with work productivity when taking work engagement into account. Work engagement did not moderate the influence of working hours on work productivity, though it attenuated the relationship between working hours and work productivity.

Visualize the quality of frozen fish using fluorescence imaging aided with excitation-emission matrix

The quality monitoring of frozen marine products has become essential in the fishery industry, where efficient and effective quality assurance is becoming increasingly important. In this study, we proposed a novel method of evaluating fish quality by combining the fluorescence excitation-emission matrix (EEM) with imaging techniques to visualize the spatial-temporal changes of freshness indices such as K-value and taste component IMP content. The result showed that the distribution of K-value and IMP content could be visualized with accuracy of R² = 0.78 and R² = 0.83, respectively. Furthermore, this innovative approach was applied to differentiate burnt meat, which is a type of abnormal meat found in many types of fish, and it was found that burnt meat could be detected even when in a frozen condition.

Optimal cut-off score of the Edinburgh Postnatal Depression Scale for major depressive episode during pregnancy in Japan

AIM

Depression during pregnancy adversely affects both mother and child. As antenatal depression is a predictor of postnatal depression, early detection might prevent postnatal depression. The Edinburgh Postnatal Depression Scale (EPDS) is frequently used during the perinatal period, but the cut-off score during pregnancy has not been verified for the Japanese population. We aimed to clarify the optimal EPDS cut-off score in mid-pregnancy in Japan.

METHODS

We recruited pregnant women aged 20 years or older at 12-24 gestational weeks and those who scored ≥9 on the EPDS were invited to participate in this study. In parallel with the EPDS, the Japanese version of the Mini-International Neuropsychiatric Interview was administered to determine diagnosis of major depressive episode. We then calculated the receiver-operator curve, sensitivity and specificity, and positive and negative predictive values for the EPDS.

RESULTS

All 210 participants were in the second trimester except for one (12 gestational weeks). Twenty participants were diagnosed with major depressive episode. With a cut-off score set at 13 points, the area under the curve was 0.956; sensitivity and specificity were 90.0% and 92.1% [Correction added on 10 November 2017, after first online publication: The percentage for specificity has been corrected from 79.0% to 92.1%.], respectively; and positive and negative predictive values were 54.5% and 98.9%, respectively.

CONCLUSION

To our knowledge, this is the first study to clarify the optimal EPDS cut-off score in the second trimester for Japan. This finding will be helpful for appropriate screening for antenatal depression in Japan.

Hepcidin-2 in mouse urine as a candidate radiation-responsive molecule

We used high-performance liquid chromatography to separate urine obtained from whole-body gamma-irradiated mice (4 Gy) before analyzing each fraction with matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry to identify radiation-responsive molecules. We identified two candidates: hepcidin antimicrobial peptide 2 (hepcidin-2) and peptide fragments of kidney androgen-regulated protein (KAP). We observed that peak increases of hepcidin-2 in urine were delayed in a dose-dependent manner (1 Gy and above); however, the amount of KAP peptide fragments showed no correlation with radiation dose. In addition, an increase in hepcidin-2 after exposure to relatively low radiation doses (0.25 and 0.5 Gy, respectively) was biphasic (at 8-48 h and 120-168 h, respectively, after irradiation). The increase in hepcidin-2 paralleled an increase in hepcidin-2 gene (Hamp2) mRNA levels in the liver. These results suggest that radiation exposure directly or indirectly induces urinary excretion of hepcidin-2 at least in part by the upregulation of Hamp2 mRNA in the liver.

Detection of breast cancer with a computer-aided detection applied to full-field digital mammography

A study was conducted to evaluate the sensitivity of computer-aided detection (CAD) with full-field digital mammography in detection of breast cancer, based on mammographic appearance and histopathology. Retrospectively, CAD sensitivity was assessed in total group of 152 cases for subgroups based on breast density, mammographic presentation, lesion size, and results of histopathological examination. The overall sensitivity of CAD was 91 % (139 of 152 cases). CAD detected 100 % (47/47) of cancers manifested as microcalcifications; 98 % (62/63) of those manifested as non-calcified masses; 100 % (15/15) of those manifested as mixed masses and microcalcifications; 75 % (12/16) of those manifested as architectural distortions, and 69 % (18/26) of those manifested as focal asymmetry. CAD sensitivity was 83 % (10/12) for cancers measuring 1-10 mm, 92 % (37/40) for those measuring 11-20 mm, and 92 % (92/100) for those measuring >20 mm. There was no significant difference in CAD detection efficiency between cancers in dense breasts (88 %; 69/78) and those in non-dense breasts (95 %; 70/74). CAD showed a high sensitivity of 91 % (139/152) for the mammographic appearance of cancer and 100 % sensitivity for identifying cancers manifested as microcalcifications. Sensitivity was not influenced by breast density or lesion size. CAD should be effective for helping radiologists detect breast cancer at an earlier stage.

Phenobarbital (PB)-induced changes in blood coagulationrelated parameters in pregnant rats, lactating rats and pups

Effects of repeated administration of phenobarbital (PB) on blood coagulation-related parameters were examined in non-pregnant, pregnant and lactating rats, and also in pups born to PB-treated lactating dams. PB was orally administered at a dose level of 80 mg/kg/day to pregnant (from gestation day (GD) 13), postpartum (from postpartum day (PPD) 7) and non-pregnant rats (from 13 weeks of age) for 7 days. Blood was collected on GD20 or PPD14 to perform blood coagulation examination. Concurrently, the blood coagulation parameters were examined in the pups. Increases in liver weight and/or hepatic cytochrome P450 content were observed in the PB-treated non-pregnant, pregnant and lactating rats. Activated partial thromboplastin time (APTT) was prolonged and anti-thrombin III (ATIII) concentration was increased in the lactating rats, while there were no changes in prothrombin time (PT) or APTT in the non-pregnant and pregnant rats. Moreover, prolongation of PT and APTT and decreases in factors VII and IX activities were observed in their pups. Thus, prolongation of blood coagulation time was confirmed in both dams and their pups following PB-administration to lactating dams. Effects of vitamin K(2) (VK(2)) on PB-induced changes in blood coagulation-related parameters of both dams and their pups were examined by co-administration with PB and VK(2) to lactating dams. PT and APTT were comparable to the control and PB-induced prolongation of blood coagulation time was improved in the pups while APTT was prolonged in dams, suggesting that VK(2) was beneficial to pups but not to dams.

Changes in blood coagulation-related parameters in phenobarbital-treated rabbits

The effects of repeated administration of phenobarbital (PB) on blood coagulation time were examined using male Japanese white SPF rabbits, which are widely used for toxicological studies. PB was administered to the rabbits by oral gavage for 2 weeks, at dose levels of 0, 12.5, 25 and 50 mg/kg/day. Blood was collected on Days 8 and 14 after each day's dosing to perform blood coagulation examination. The liver was excised, weighed and examined histopathologically. Activated partial thromboplastin time (APTT) was prolonged at dose levels of 12.5 mg/kg/day or more and Thrombotest (TBT) was prolonged at 50 mg/kg/day on Day 8. APTT was prolonged at dose levels of 12.5 mg/kg/day or more, TBT was prolonged at 25 mg/kg/day or more and factor IX activity decreased at 50 mg/kg/day on Day 14. At pathological examination, liver weight increased at dose levels of 25 mg/kg/day or more, and a ground-glass appearance of the hepatocytes was observed in the central and middle parts of lobules at 12.5 mg/kg/day or more. However, changes in factor VII or X activity or prolongation of prothrombin time (PT) were not observed. Therefore, prolongation of blood coagulation time by PB administration in rabbits was considered to be due to PB's effect on the endogenous pathway alone. Moreover, an increase in anti-thrombin III (ATIII) concentration was noted at 50 mg/kg/day; however, no change was noted at dose levels of 25 mg/kg/day or less. This suggests that the contribution of ATIII to the PB-induced prolongation of coagulation time in rabbits was small.

[An autopsied case of pachymeningitis associated with a ruptured, cerebral aneurysm due to Aspergillus infection]

We reported a 64-years-old woman with pachymeningitis associated with a ruptured mycotic cerebral aneurysm due to Aspergillus infection. She had suffered from diabetes mellitus and been treated since she was 49 years old. She complained of headache at the age of 62 and loss of her left visual acuity three months later. She was treated by the pulse therapy of methylprednisolone as neuritis retrobulbaris and her visual acuity recovered. But her headache continued. Three months later, her right visual acuity was lost, and the pulse therapy was not effective this time. Six months later, she died of subarachnoid hemorrhage following acute meningitis. The autopsy was granted, but limited to the cranial cavity. Macroscopically, it disclosed brownish thickened dura around sella turucica involving trigeminal ganglion and optic nerve, and fresh subarachnoid hemorrhage in the basal cisterns and a ruptured aneurysm (3 mm in diameter) between internal carotid and posterior cerebral artery on the left side. Histologically, the brownish thickened dura was infiltrated by lymphocytes, plasma cells, and multinucleated giant cells. The wall around the aneurysm was infiltrated by lymphocytes and plasma cells as well as many fungi. Immunohistochemistry demonstrated the presence of Aspergillus in the thickened dura and the arterial wall around the aneurysm. There were lymphocytes and plasma cell infiltration in the basal subarachnoid space and scattered microabcesses in the brain. Although the first entry of Aspergillus to the dura was unclear, we assume that the final intravascular dissemination of Aspergillus from the dura caused meningitis and mycotic aneurysm.

Sertoli-stromal cell tumor of the ovary: immunohistochemical, ultrastructural, and genetic studies

The Sertoli-stromal cell tumor (SSCT) of the ovary shows a histologic resemblance to developing or adult testes and is often associated with virilization caused by tumor-produced androgenic hormone. In spite of the unique manifestation of SSCT, detailed characteristics of this tumor are still obscure. The mechanism by which SSCT occurs has not yet been determined. Six SSCTs were studied immunohistochemically, ultrastructurally, and by polymerase chain reaction (PCR) for the presence of sex-determining region Y (SRY) gene and the X chromosome activation state. Immunohistochemically, Sertoli-like cells of SSCT were positive not only for alpha-inhibin but also low-molecular-weight cytokeratin. In control testes, the expression of alpha-inhibin and cytokeratin was limited to a Sertoli cell component and rete testis, respectively. Ultrastructurally, tumor cells composing hollow tubules had an elongated nucleus with deep indentation and annulate lamellae, which are characteristic structures of mature Sertoli cells. In addition, they had studded microvilli on the apical surface and frequent desmosomes, which are structures noted in the cells of rete testis. Histologically, tumor cells of hollow tubules sometimes pouted into the lumen, as did the cells of tubulae rete, entrance into rete testis from seminiferous tubules. All of these findings indicate that some tumor cells of a SSCT show simultaneous differentiation into both Sertoli cells and cells of rete testis. SRY gene was not detected in any cases, and the X chromosome activation pattern was the same as that of the female control.

Toxic shock-like syndrome with flu-like prodrome: a possible role of 'enhancing tissue focus' for streptococcal toxic shock

We describe three patients with invasive group A streptococcal infection, admitted during the 3 months between November 1996 and February 1997. All patients were previously healthy Japanese women who developed a profound shock, with a rapidly fatal outcome, after experiencing flu-like symptoms. All cases conformed to the case definition of toxic shock-like syndrome (TSLS).Currently, the pathogenic mechanism of TSLS remains unclear. Known microbial virulence factors can not sufficiently explain the occurrence of TSLS, and it has been generally considered that host factors may be contributory. On pathological examination, each patient had one organ or tissue that was most severely involved: Case 1 a non-penetrating trauma; Case 2 a pregnant uterus; and Case 3 a pulmonary lesion reminiscent of lymphocytic interstitial pneumonia. On the basis of clinicopathological features of these cases, we propose that the coexistence of 'enhancing tissue focus' may be one of host factors for the progression of TSLS in patients infected with non-invasive GAS.

Effects of triphenyltin on growth and viability of K562 leukemia cells

The effects of triphenyltin on growth and viability of K562 human leukemia cells were examined using a flow cytometer with fluorescent dyes, ethidium bromide, fluo-3-AM, and propidium iodide. Triphenyltin at concentrations ranging from 30 nM to 1 μM inhibited the growth of K562 cells in a dose-dependent manner when the cells were incubated with triphenyltin at respective concentrations for 72 h. Triphenyltin at 100 nM slowed the rate of growth without affecting the viability. Triphenyltin at 300 nM or higher greatly decreased the viability of K562 cells. Triphenyltin at 300 nM increased the concentration of intracellular Ca(2+) and induced cell cycle arrest in G2/M phase and apoptosis in K562 cells. The concentration of triphenyltin inducing 50% inhibition of growth of K562 cells was lower than those of cisplatin, diphenyltin, monophenyltin, triethyltin and trimethyltin. However, tributyltin was equally toxic. Results suggest that there are several types of mechanisms for the inhibitory action of triphenyltin on the growth of K562 cells, being dependent on its concentration.

Cytotoxic actions of FTY720, a novel immunosuppressant, on thymocytes and brain neurons dissociated from the rat

Effects of FTY720 (2-amino-2-(2-[4-octylphenyl]ethyl)-1,3-propanediol HCl), a novel immunosuppressant, were examined on neurons and thymocytes respectively dissociated from rat brains and thymus glands using a flow cytometer to see if FTY720 exerts cytotoxic actions not only on spleen cells as previously reported but also on the other cells. FTY720 at a concentration of 10 microM deteriorated almost all of the thymocytes, while it was not the case for brain neurons. FTY720 increased the intracellular concentration of Ca2+ ([Ca2+]i) of thymocytes in both the presence and absence of external Ca2+, although the [Ca2+]i increased by FTY720 in the presence of external Ca2+ was much greater than that in the absence of external Ca2+. Thus, FTY720 may increase the membrane permeability of Ca2+ and release Ca2+ from intracellular Ca2+ stores in thymocytes. Furthermore, the number of thymocytes stained with ethidium, a dye impermeant to intact membranes, time-dependently increased after drug application. Therefore, FTY720 at concentrations of 3 - 10 microM non-specifically increases the membrane permeability of thymocytes, resulting in necrotic cell death, although FTY720 at micromolar concentrations was reported to induce apoptosis of spleen cells.

New curcuminoids isolated from Zingiber cassumunar protect cells suffering from oxidative stress: a flow-cytometric study using rat thymocytes and H2O2

Effects of new complex curcuminoids (cassumunin A and cassumunin B) isolated from tropical ginger, Zingiber cassumunar, were examined in dissociated rat thymocytes suffering from oxidative stress induced by 3 mM hydrogen peroxide by using a flow cytometer and ethidium bromide. The effects were compared with those of curcumin, a natural antioxidant, whose chemical structure is included in those of cassumunins A and B. Pretreatment of rat thymocytes with the respective cassumunins at concentrations ranging from 100 nM to 3 microM dose-dependently prevented the hydrogen peroxide (H2O2)-induced decrease in cell viability. It had the same action, although less effective, against the treatment with cassumunin A or B (3 microM) immediately after or 60 min after start of the oxidative stress. Respective potencies of cassumunins A and B in protecting the cells suffering from H2O2-induced oxidative stress were greater than that of curcumin. It is suggested that cassumunins A and B may possess a potent protective action on living cells suffering from oxidative stress.

Toxic shock-like syndrome caused by non-group A beta-hemolytic streptococci

Two patients with rapidly developing shock, multisystem organ failure, and destructive soft-tissue infection caused by groups G and C streptococci are described. Both patients died rapidly despite aggressive treatment. The clinical characteristics cannot be distinguished from those of toxic shock-like syndrome, but Streptococcus pyogenes was not recovered. These strains did not produce any previously identified type of streptococcal pyrogenic exotoxins. These findings suggest that toxic shock-like syndrome can be caused not only by group A but also groups G and C streptococci. The causative strains of toxic shock-like syndrome may have something in common with unknown virulent factors for this syndrome.

An autopsied case of acute myocarditis with myocardial calcification

A 47-year-old woman was admitted with fever, hypotension, an elevated serum creatinine kinase level, and electrocardiographic abnormalities, which led to the diagnosis of acute myocarditis. She was placed on percutaneous cardiopulmonary support because of hemodynamic collapse on the third hospital day. Serial echocardiography showed gradual recovery of profound hypokinesis and edematous thickening of the left ventricle, but she died of sepsis on the 17th day without overt renal insufficiency or electrolytic abnormalities. Autopsy revealed myocardial necrosis with lymphocytic infiltrates and extensive myocardial calcification. Calcification was dense in the area of severe myocardial necrosis, and the distribution of calcium deposits suggested that the calcification was a consequence of significant inflammation of the myocardium. Recovery of regional wall motion was prominent in the area of severe inflammatory change. Dissociation between the pathologic and echocardiographic findings suggested the possibility of functional reversibility of severely damaged myocardium and possible mechanisms of abnormal contractile function other than inflammatory change.

Fluorescent estimation on cytotoxicity of methylmercury in dissociated rat cerebellar neurons: its comparison with ionomycin

To study the cellular basis of the neurotoxicity of methylmercury, the effects of methylmercury on dissociated rat cerebellar neurons were examined using a flow cytometer, a confocal laser microscope and three fluorescent dyes, fluo-3 for monitoring the changes in intracellular Ca(2+) concentration ([Ca(2+)](i)) and for detecting live neurons, ethidium for assessing the neurons that are dead or have compromised membranes, and 5-chloromethylfluorescein (CMF) for estimating the cellular content of nonprotein thiols. Methylmercury at concentrations of 1 μM or greater increased the [Ca(2+)](i) of almost all neurons. Prolonged exposure to methylmercury (3 and 10 μM) produced a further increase in [Ca(2+)](i), in association with compromising membranes in some neurons. Thereafter, methylmercury induced blebs on membranes of some neurons with increased [Ca(2+)](i). Methylmercury at concentrations of 0.3 μM or greater dose-dependently decreased the cellular content of nonprotein thiols. Results suggest that methylmercury may induce the loss of membrane integrity through destabilized Ca(2+) homeostasis and oxidative stress in mammalian brain neurons.

Flow-cytometric analysis on kainate-induced decrease in the cellular content of non-protein thiols in dissociated rat brain neurons

In order to study the kainate-induced oxidative stress on brain neurons, the effect of kainate on cellular content of glutathione in rat cerebellar neurons were examined using a flow cytometer and 5-chloromethylfluorescein, a fluorescent dye for cellular non-protein thiols (mainly glutathione). Kainate at concentrations ranging from 30 microM to 1 mM produced a dose-dependent decrease in cellular content of glutathione. Exposure of neurons to kainate at concentrations of 300 microM or greater seemed to deplete cellular glutathione. Potency of kainate in reducing cellular content of glutathione was greater than those of glutamate and N-methyl-D-aspartate (NMDA). Kainate-induced decrease in cellular content of glutathione was partly attenuated by 6-nitro-7-cyano-quinoxaline-2,3-dione, a blocker of non-NMDA receptors and removal of external Ca2+. Results indicate that kainate causes Ca2(+)-dependent oxidative stress that decreases the cellular content of glutathione via activation of non-NMDA type of glutamate receptors.

Oxidative stress-induced increase in intracellular Ca2+ and Ca(2+)-induced increase in oxidative stress: an experimental model using dissociated rat brain neurons

In order to study the oxidative stress-induced change in intracellular concentration of Ca2+ ([Ca2+]i) and Ca(2+)-induced oxidative stress, effects of hydrogen peroxide and ionomycin, a calcium ionophore, on rat cerebellar neurons were examined using a flow cytometer and fluorescent dyes: fluo-3 for monitoring [Ca2+]i; 2',7'-dichlorofluorescin, for reactive oxygen species; and 5-chloromethylfluorescein, for cellular nonprotein thiols. Oxidative stress induced by hydrogen peroxide dose-dependently increased [Ca2+]i and decreased the content of nonprotein thiols. Ionomycin increased oxidative metabolism and decreased the content of nonprotein thiols. Results suggest that oxidative stress induces an increase in [Ca2+]i while an increase in [Ca2+]i increases oxidative stress in neurons.

Fluorescent estimation of H2O2-induced changes in cell viability and cellular nonprotein thiol level of dissociated rat thymocytes

We have developed a procedure to simultaneously estimate cell viability and the cellular level of nonprotein thiol (presumably glutathione) using two fluorescent dyes, 5-chloromethylfluorescein (5CMF) and ethidium, and rat thymocytes. Diethylmaleate and N-ethylmaleimide reduced, respectively, the intensity of 5CMF fluorescence to 0.23 and 0.1, relative to the control. Incubation with buthionine sulfoximine, an inhibitor of glutathione synthesis, decreased the intensity of 5CMF fluorescence to 0.61. Results indicate that 5CMF fluorescence can be attenuated by agents that decrease the level of cellular nonprotein thiols, suggesting that 5CMF fluorescence is utilized for estimating the level of cellular glutathione. Hydrogen peroxide (10 microM to 3 mM) reduced the intensity of 5CMF fluorescence in a dose-dependent manner and increased the number of thymocytes stained with ethidium (presumably dead cells or cells with compromised membranes) at concentrations of 300 microM or greater. Reduction of cellular glutathione level seems to precede cell death in which oxidative stress is involved.

Flow cytometric analysis of the H2O2-induced increase in intracellular Ca2+ concentration of rat thymocytes

The effect of hydrogen peroxide (H2O2) on the intracellular Ca2+ concentration ([Ca2+]i) of rat thymocytes was examined by a flow cytometer and two fluorescent dyes, fluo-3-AM and ethidium bromide, a dye impermeant to intact membranes, to characterize the H2O2-induced increase in [Ca2+]i. H2O2 at concentrations greater than 30 microM dose-dependently increased the [Ca2+]i of thymocytes which were not stained with ethidium. Removal of external Ca2+ greatly reduced the degree of H2O2-induced increase in [Ca2+]i. However, H2O2 still increased the [Ca2+]i under the external Ca(2+)-free condition. Diethylmaleate, which is known to produce a chemical depletion of cellular nonprotein thiol, significantly increased the [Ca2+]i. Dithiothreitol, which is used to protect cellular nonprotein thiol, slightly decreased the [Ca2+]i, but greatly reduced the H2O2-induced increase in [Ca2+]i. Therefore, it is considered that H2O2 may increase the [Ca2+]i through a mechanism related to the effects of H2O2 on the cellular nonprotein thiol.

Flow-cytometric estimation on glutamate- and kainate-induced increases in intracellular Ca2+ of brain neurons: a technical aspect

Effects of glutamate and kainate on the intracellular Ca2+ concentration ([Ca2+]i) in a large population (several thousand) of dissociated cerebellar granule cell neurons were evaluated using a flow-cytometer and a combination of two fluorescent dyes, fluo-3-AM for estimating [Ca2+]i and ethidium bromide for removing neurons that had compromised membranes from the cell population examined. The number of neurons responding to glutamate or kainate in augmenting the fluo-3 fluorescence increased in a dose-dependent manner. The number of neurons responding to kainate was much greater than that to glutamate. CNQX, a blocker of non-NMDA receptors, completely blocked the response elicited by kainate while the complete blockade of this glutamate-induced response was made by a combination of MK-801, a NMDA receptor blocker, and CNQX. Nicardipine, a calcium antagonist, decreased the number of neurons responding to glutamate and kainate, suggesting involvement of voltage-dependent calcium channels. These results indicate that the flow-cytometric measurement of glutamate and kainate responses has the potential to provide answers to such questions as what percentage of the population of neurons respond to these amino acids and what is the resulting distribution of [Ca2+]i.

Immunohistochemical properties of malignant mesothelioma cells in histologic and cytologic specimens

Although there is general agreement that immunohistochemical methods can aid in the pathologic diagnosis of malignant mesothelioma, some studies have produced conflicting results. To obtain comparable and reproducible results, unequivocal malignant mesotheliomas were studied with the biotin-streptavidin-peroxidase complex method in 14 formalin-fixed, paraffin-embedded tissue specimens, 5 ethanol-fixed smear slides and 3 cold acetone-fixed smear slides. The expression of CA-125, epithelial membrane antigen (EMA) and vimentin by malignant epithelial mesothelioma cells was hindered by their poor preservation in formalin fixative. Cytologic specimens fixed in cold acetone were the best type for immunohistochemistry. The majority of malignant epithelial mesothelioma cells in the smear slides fixed in cold acetone were positive for CA-125, EMA, low-molecular-weight cytokeratin and vimentin, but none of them were positive for carcinoembryonic antigen, CA-19-9, epithelial antigen, high-molecular-weight cytokeratin or Leu-M1.

Epstein-Barr virus related gastric cancer in Japan: a molecular patho-epidemiological study

Epstein-Barr virus (EBV) involvement in gastric carcinoma has been demonstrated by the presence of EBV genomes and EBV-encoded small RNA (EBER) in the carcinoma cells, monoclonal proliferation of EBV-infected carcinoma cells and elevated antibody titers. The present study was conducted to investigate the prevalence of EBV involvement among gastric carcinomas observed in nine Japanese cities with varying gastric cancer rates. In situ hybridization of EBER-1 was applied to paraffin sections from 1848 carcinomas observed in 1795 cases and EBV involvement was detected based on uniform hybridization in carcinoma cells. Epstein-Barr virus was detected in 6.6% of lesions and 6.7% of cases. The rate of EBV involvement did not vary significantly for each city and there was no correlation with underlying gastric cancer mortality rates. Thus, geographic variation of gastric cancer rates within Japan cannot be explained in terms of EBV involvement. Epstein-Barr virus-related gastric carcinoma is one of the most common EBV-related tumors in Japan. The involvement of EBV was significantly more frequent among males than among females, mainly for cancers occurring in the upper and middle part of the stomach, and exhibited more variation by cell type among males. These observations suggest that other factors yet to be discovered may modulate the causal role of EBV in gastric carcinogenesis.

Functioning ovarian carcinoids induce severe constipation

Five patients with ovarian carcinoid who had severe constipation for a long period preoperatively showed marked reduction of this symptom postoperatively. Because this phenomenon was believed to be caused by some biologically active substance rather than a mechanical effect of the tumor, reactivity to 17 amine and peptide hormones was studied immunohistochemically in these patients. Numerous peptide YY (PYY)-positive cells were detected, with PYY-positive cells representing more than 50% of all carcinoid tumor cells in each patient. PYY, which has a pharmacologic inhibitory action on intestinal motility, was presumably the cause of the constipation in these patients.

Chronic lymphocytic leukemia associated with von Recklinghausen neurofibromatosis

We report a 62-year-old female, with von Recklinghausen neurofibromatosis and chronic lymphocytic leukemia, whose mother and son both had neurofibromatosis and died of digestive tract cancers. The patient died of pneumonia 3 years after the initiation of therapy. Leukemia reported in association with neurofibromatosis are predominantly nonlymphocytic and limited to childhood. The type of association found in our patient has not been reported previously.

Cancer antigen 125, carcinoembryonic antigen, and carbohydrate determinant 19-9 in ovarian tumors

The authors studied data of combination assays of tumor markers, because simultaneous elevation of different types of tumor markers in the serum was puzzling. They interpreted such phenomena regarding cancer antigen 125, carcinoembryonic antigen, and carbohydrate determinant 19-9 in ovarian tumors. The tissue expression of the antigens was compared with preoperative serum levels. Several different factors were found to cause the simultaneous elevation of two or three of these markers in the serum. Furthermore, even when the levels of some of the tumor markers were raised in the serum, the ovarian tumor did not always produce the marker by itself. This study indicates that immunohistochemical identification of a marker in tumor tissue is prerequisite to the use of that marker in the serum to monitor disease status.

AKR leukemia-specific surface antigens acquired by malignant transformation: their common and individual specificities

Antisera against five newly established AKR spontaneous leukemias (KSL) prepared by immunization of KSL cells in (C57B1/6 X C3Hf/He)F1 mice were preabsorbed with non-leukemic AKR lymphoid cells to remove antibodies against virus-associated surface antigens and alloantigens. In absorption tests the antisera showed no cross-reaction by immunofluorescence microscopy with thymocyte, fetal, male-specific H-Y, E and X.1 antigens; with known Gross murine leukemia virus-associated antigens; or with cell surface antigens on Friend, Moloney and Rauscher virus-induced tumors. It was thus shown that the antigens detected were leukemia-specific, were acquired by malignant transformation, and consisted of two types: (1) a common antigen in all the KSL, and (2) individual antigens found in four of the KSL which showed distinct patterns of partial cross-reactivity with the other KSL.