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To characterize the compliance status of adjuvant endocrine therapy (aET) and its relationship with disease-free survival (DFS) in hormone receptor-positive (HR+) and HER2-negative (HER2-) in Chinese breast cancer (BC) patients with first tumor recurrence.All women with primary unilateral stage I - III HR+HER2- BC and first tumor recurrence in 2008 - 2018 at our institution were identified. Full (vs. none/partial) compliance of aET was classified from records. Multivariate Cox regression estimated the hazard ratio (HR), its 95% confidence interval (CI), and p value. DFS. Covariates included age, T stage, N stage, pathology, tumor grade, LVI, chemotherapy, radiotherapy. Results: A total 258 patients had average age 47.4 years at BC diagnosis and median DFS 31.7 months. Patients with ipsilateral (contralateral) region and organ recurrence were 47.7% (19.8%) and 71.9%. Compared to the patients with none/partial compliance of aET, the full compliance patients (54.3% ) had a higher DFS (median 35.0 vs. 25.2 months, p=0.009). Multivariate analysis showed that the full compliance of aET was associated with a lower HR 0.614 (95%CI 0.467 - 0.807, p0.001) on recurrence. Early discontinuation (67.5%, 56/83) due to the drug side effects was the top reason for partial compliance of aET.Full compliance of aET was quite low in Chinese HR+HER2- BC patients. However, it was associated with a 38.6% lower risk of first tumor recurrence. To search for effective tools to improve the compliance of aET in this population should be stressed.

Breast cancer (BC) remains the most common cancer among women worldwide. Hormone receptor-positive (estrogen receptor- and/or progesterone receptor-positive) BC represents 70% of all cases. Advances in the treatment of disease lead to improved patient survival. As a result, quality-of-life (QoL) becomes a major concern in clinical practice. This study aimed to assess the impact of socio-demographic, clinical and treatment-related factors on QoL among patients with BC treated with adjuvant endocrine therapy. We used the Functional Assessment of Cancer Therapy – Breast questionnaire to evaluate QoL. In the entire cohort, multivariate analysis determined age and switching treatment from tamoxifen to aromatase inhibitors to be significant positive coefficients of QoL, while comorbidity tended to be associated with lower scores. Education level and chemotherapy were significant determinants of QoL in the tamoxifen group, while comorbidity, surgery type, radiotherapy and disease stage had a significant impact on QoL in the aromatase inhibitor group. These findings can be utilized to identify certain subgroups that may need greater supportive care.

Daily adjuvant endocrine therapy (AET) for 5 or 10 years is the standard of care for women diagnosed with non-metastatic hormone receptor-positive breast cancer. However, many women experience AET-related issues that may hamper quality of life and adherence. Here, we aimed to describe women's perceptions of motivational interviewing (MI)-guided consultations delivered by a trained nurse navigator over the telephone to enhance AET adherence.Eighteen women who were first prescribed AET for non-metastatic breast cancer in the last 5 years, who self-reported AET-related issues, and who participated in at least two MI-guided consultations over a year were interviewed about their perceptions of the intervention, using a semi-structured interview guide. Audio recordings were transcribed verbatim and analyzed using a thematic analysis approach.Three main themes emerged from the data about women's perceptions on MI-guided consultations. These consultations were described as (1) a person-centred experience, (2) providing key information about AET, and (3) supportive of present and future AET experience, by contributing to AET side-effect management, motivation, adherence, calming negative emotions, improving well-being and self-esteem, and making women to feel empowered.Nurse-led telephone-based MI-guided consultations about AET were found to respond to participants' needs and to enhance participants' perceptions of being informed and being supported in experiencing various facets of AET. Telephone-based consultations for AET are perceived as a promising strategy in an increasing virtual care world.

Objectives Studies suggest that cognitive training and physical activity can improve age-related deficits in dual-task performances. However, both of these interventions have never been compared in the same study. This article investigates the improvement in dual-task performance in 2 types of exercise training groups and a cognitive training group and explores if there are specific dual-task components that are more sensitive or more likely to improve following each type of training. Methods Seventy-eight healthy inactive participants older than the age of 60 (M = 69.98, SD = 5.56) were randomized to one of three 12-week training programs: aerobic training (AET) = 26, gross motor abilities (GMA) = 27, and cognition (COG) = 25. Before and after the training program, the participants underwent physical fitness tests, and cognitive evaluations involving a computerized cognitive dual task. The AET consisted of high- and low-intensity aerobic training, the GMA of full-body exercises focusing on agility, balance, coordination, and stretching, and the COG of tablet-based exercises focusing on executive functions. Results Repeated-measures analysis of variance on reaction time data revealed a group × time interaction (F(2,75) = 11.91, p < .01) with COG having the greatest improvement, followed by a significant improvement in the GMA group. Secondary analysis revealed the COG to also improve the intraindividual variability in reaction time (F(1,24) = 8.62, p < .01), while the GMA improved the dual-task cost (F(1,26) = 12.74, p < .01). Discussion The results show that physical and cognitive training can help enhance dual-task performance by improving different aspects of the task, suggesting that different mechanisms are in play.

Background Women undergoing treatment for breast cancer require frequent clinic visits for maintenance of therapy. With COVID-19 causing health care disruptions, it is important to learn about how this population’s access to health care has changed. This study compares self-reported health care utilization and changes in factors related to health care access among women treated at a cancer center in the mid-South US before and during the pandemic. Methods Participants (N = 306) part of a longitudinal study to improve adjuvant endocrine therapy (AET) adherence completed pre-intervention baseline surveys about their health care utilization prior to AET initiation. Questions about the impact of COVID-19 were added after the pandemic started assessing financial loss and factors related to care. Participants were categorized into three time periods based on the survey completion date: (1) pre-COVID (December 2018 to March 2020), (2) early COVID (April 2020 – December 2020), and later COVID (January 2021 to June 2021). Negative binomial regression analyses used to compare health care utilization at different phases of the pandemic controlling for patient characteristics. Results Adjusted analyses indicated office visits declined from pre-COVID, with an adjusted average of 17.7 visits, to 12.1 visits during the early COVID period (p = 0.01) and 9.9 visits during the later COVID period (p p = 0.05). Among COVID period participants, the proportion reporting changes/gaps in health insurance coverage increased from 9.5% participants during early-COVID to 14.8% in the later-COVID period (p = 0.05). The proportion reporting financial loss due to the pandemic was similar during both COVID periods (34.3% early- and 37.7% later-COVID, p = 0.72). The proportion of participants reporting delaying care or refilling prescriptions decreased from 15.2% in early-COVID to 4.9% in the later-COVID period (p = 0.04). Conclusion COVID-19 caused disruptions to routine health care for women with breast cancer. Patients reported having fewer office visits at the start of the pandemic that continued to decrease even after vaccines were available. Fewer patients reported delaying in-person care as the pandemic progressed.

Contains fulltext : 287764.pdf (Publisher’s version ) (Open Access) OBJECTIVE: Non-adherence to adjuvant endocrine therapy (AET) for breast cancer leads to increased recurrence and mortality risk and healthcare costs. Evidence on feasible, effective AET adherence interventions is scarce. This paper describes the systematic adaptation of the cost-effective adherence improving self-management strategy (AIMS) for patients with HIV to AET for women after breast cancer treatment. METHODS: We followed the intervention mapping protocol for adapting interventions by conducting a needs assessment, reviewing target behaviours and determinants, reassessing behaviour change methods and adapting programme content. Therefore, we performed a literature review, consulted behavioural theory and organised nine advisory board meetings with patients and healthcare professionals. RESULTS: Non-adherence occurs frequently among AET users. Compared to HIV treatment, AET is less effective, and AET side effects are more burdensome. This drives AET treatment discontinuation. However, the key determinants of non-adherence are largely similar to HIV treatment (e.g. motivation, self-regulation and patient-provider relationship); therefore, most strategies in AIMS-HIV also seem suitable for AIMS-AET. Modifications were required, however, regarding supporting patients with coping with side effects and sustaining treatment motivation. CONCLUSION: AIMS seems to be a suitable framework for adherence self-management across conditions and treatments. Intervention mapping offered a transparent, systematic approach to adapting AIMS-HIV to AET.

Objective: The use of adjuvant endocrine therapy (AET) after primary treatment of hormone receptor-positive breast cancer reduces the risk of recurrence and mortality. However, non-adherence is still common. Limited consideration has been given to how users deal with AET and the role of pharmaceutical care. Therefore, this study aims to obtain insight into the needs and wishes of women using AET regarding pharmaceutical care and eHealth. Methods: This is a qualitative explorative study comprising semi-structured interviews (n = 16) and a focus group (n = 5) among women who use or used AET after primary early-stage breast cancer (EBC) treatment using a thematic analysis approach. Results: Three themes emerged from the interviews and focus group: (1) experiences with AET use, (2) experiences with provided information and (3) needs and wishes regarding pharmaceutical care. Most women were highly motivated to use AET and indicated to have received useful information on AET. However, many expressed a strong need for more elaborate tailored and timely provided information on AET. They acknowledged the accessibility of pharmacists but reported that currently, pharmacists are hardly involved in AET care. Several women considered eHealth useful to obtain counselling and reliable information. Conclusion: Women need more comprehensive information and follow-up in primary setting after initial cancer treatments. A more elaborate role for the pharmacy and eHealth/mHealth, especially with regard to counselling on side effects and side effect management, could potentially improve pharmaceutical care.

Endoplasmic reticulum (ER) stress poses a new pathological mechanism for metabolic-associated fatty liver disease (MAFLD). MAFLD treatment has encompassed renin-angiotensin system (RAS) blockers and aerobic exercise training, but their association with hepatic ER stress is not well known. Therefore, we aimed to compare the effects of hepatic RAS modulation by enalapril and/or aerobic exercise training over ER stress in MAFLD caused by a diet-induced obesity model.C57BL/6 mice were fed a standard-chow (CON, n = 10) or a high-fat (HF, n = 40) diet for 8 weeks. HF group was then randomly divided into: HF (n = 10), HF + Enalapril (EN, n = 10), HF + Aerobic exercise training (AET, n = 10), and HF + Enalapril+Aerobic exercise training (EN + AET, n = 10) for 8 more weeks. Body mass (BM) and glucose profile were evaluated. In the liver, ACE and ACE2 activity, morphology, lipid profile, and protein expression of ER stress and metabolic markers were assessed.Both enalapril and aerobic exercise training provided comparable efficacy in improving diet-induced MAFLD through modulation of RAS and ER stress, but the latter was more efficient in improving ER stress, liver damage and metabolism.This is the first study to evaluate pharmacological (enalapril) and non-pharmacological (aerobic exercise training) RAS modulators associated with ER stress in a diet-induced MAFLD model.

BACKGROUND: Affective Events Theory (AET) postulates that job characteristics have an impact on job attitudes and work behaviour via affective events and reactions. However, the display of positive emotions can be rather problematic in undertakers and be in conflict with displaying compassion. OBJECTIVE: This study examines work events eliciting various emotions in the work of undertakers and how display of emotions in this profession affects job satisfaction. We thereby focus on AET and extend this by investigating time pressure as a moderator of the relationship between autonomy, positive emotions and job satisfaction. METHODS: First, we collected specific affective work events of undertakers in a pilot interview study. Second, N = 112 undertakers participated in a cross-sectional survey measuring affective events, emotional display, commitment to display compassion, autonomy, time pressure, job satisfaction and work engagement. RESULTS: Experiencing positive emotions at work is beneficial even in undertakers. Additionally, autonomy was associated with positive emotions particularly under high time pressure and low commitment to display compassion moderated the link between work events and showing compassion. CONCLUSIONS: Taken together, undertakers’ well-being is associated in complex ways with the interplay of positive emotions, autonomy and time pressure at work and individual differences in commitment for displaying compassion to clients.

Though adjuvant endocrine therapy (AET) has proven efficacy in treating hormone receptor-positive (HR-positive) breast cancer, patient adherence to AET and continuation of treatment as recommended by guidelines remain suboptimal, especially for low-income patients.To quantify timelines for initiating AET and assess their association with short- and long-term adherence and continuation of AET in low-income women with breast cancer.This population-based retrospective cohort study included women younger than 65 years diagnosed with first primary HR-positive breast cancer between January 1, 2007, and December 31, 2013, followed up for 5 years after the first use of AET through December 2018, and identified from the linked Missouri Cancer Registry and Medicaid claims data set.Time to initiation (TTI) as days from the date of last treatment (surgery, radiotherapy, or chemotherapy) to the first date of AET prescription fill.The main outcomes were adherence to AET as medication possession ratio of 80% or greater and continuation of AET as no gap in medication supply for at least 90 days. Odds ratios (ORs) of adherence and continuation over 1 to 5 years were estimated using logistic regression adjusted for demographic, clinical, and neighborhood variables. Analyses were performed between September 1, 2020, and May 31, 2022.Among 1711 patients, median TTI was 53 (IQR, 26-117) days. A total of 1029 patients (60.1%) were aged 50 to 64 years old, 1270 (74.2%) were non-Hispanic White, and 1133 (66.2%) were unmarried. In the first year after initiation, 1317 (77.0%) were adherent and 1015 (59.3%) continued AET. Over the full 5 years, 376 (22.0%) were adherent and 409 (23.9%) continued AET. Longer TTI was significantly associated with poorer adherence at every year, with an OR of 0.97 (95% CI, 0.95-0.99) for 1-year adherence and an OR of 0.94 (95% CI, 0.90-0.97) for 5-year adherence per 1-month increase in TTI. Longer TTI was also associated with lower odds of short-term, but not long-term, continuation (OR, 0.97 [95% CI, 0.95-0.99] for 1-year continuation and 0.98 [95% CI, 0.96-0.99] for 2-year continuation).In this cohort study, longer time to AET initiation was associated with lower odds of short-term and long-term adherence to AET in Medicaid-insured patients with breast cancer. Therefore, early interventions targeting treatment initiation timelines may positively impact adherence throughout the course of treatment and, therefore, outcomes.

We report a novel technique of flexible endoscopy with noninvasive ventilation (NIV) and sustained pharyngeal inflation (FE-NIV-SPI) in assessing aeroesophageal tracts (AET) to facilitate early detection of laryngeal clefts in infants.Medical charts and flexible endoscopy videos of the children who were diagnosed with laryngeal cleft in a tertiary care hospital between January 2000 and December 2020 were retrospectively reviewed and analyzed. The FE-NIV-SPI technique had been applied to all these children.Totally, 12 infants with laryngeal cleft were identified. This equates to a prevalence of 0.28% in all the children who underwent flexible endoscopy at our institution. Their mean age was 5.0 ± 4.9 months and mean body weight was 4.7 ± 2.3 kg. Nine (75%) infants were referred in without laryngeal cleft diagnosis, which was missed by 11 prior bronchoscopy and 5 computer tomography examinations. With the FE-NIV-SPI technique, the pharyngolaryngeal space could be pneumatically dilated permitting a detailed assessment. All laryngeal cleft types and coexisting AET lesions were visualized at the first FE-NIV-SPI examination with a mean time of 4.2 ± 0.9 min; they were eight Type I, two Type II, and one Type III. Ten (83.3%) infants had coexisting airway malacia.Routine use of FE-NIV-SPI technique can help in early detection of laryngeal clefts and other associated AET lesions. Further multicenter collaborative investigations are essential to verify the early detection of this rare and occult lesion of the laryngeal cleft with this technique.

Hiatal hernia (HH) is associated with gastroesophageal reflux disease (GERD); the effect of HH size on GERD is not well defined. To evaluate the relationship between HH size as measured by high-resolution esophageal manometry (HREM) and reflux parameters on esophageal pH-impedance testing (multichannel intraluminal impedance-pH [MII-pH]) to define HH sizes associated with GERD. HREM and MII-pH studies were reviewed. The relationship of HH size to other parameters was analyzed with multivariable logistic regression. Correlation coefficients were determined using Spearman and Pearson’s tests. A total of 897 patients underwent both HREM and MII-pH. There were 529 (58.9%) patients with HH size 2 cm, are associated with more severe GERD parameters.

Despite adjuvant endocrine therapy (AET) considerably reducing mortality and recurrence in hormonal receptor-positive (HR+) breast cancer (BC) patients, acceptance of AET remains an issue. The reasoning behind the lack of acceptance is complex and multifactorial, and some associated risk factors have been previously analyzed. Our study aims to assess women's beliefs and concerns toward AET and women's trust in the treating physician, focusing on determining the importance of these factors in the acceptance of AET.Out of n = 539, n = 269 women with HR + BC participated in a cross-sectional online survey. The main study variables were AET necessity beliefs and concerns (Beliefs about Medicines Questionnaire) and the trust in treating physicians. A binary hierarchical logistic regression was applied to predict AET acceptance.We did not observe a meaningful mean difference in the necessity beliefs between women who accepted versus refused AET by the time of study conduct. Women with ongoing AET intake indicated significantly higher trust in their treating physician (d = 0.57) and have lower concerns (d = -1.65) regarding AET than women who had declined or discontinued AET prematurely. Results of the logistic regression demonstrated that after adjusting for clinical factors (e.g., prognosis, age), higher trust and lower concerns significantly increased the likelihood of accepting AET treatment.Our results demonstrate the importance of discussing potential concerns regarding AET and establishing a trustful patient-physician relationship, which outweighs non-modifiable factors such as cancer prognosis.

Purpose Side-effects of adjuvant endocrine therapy (AET) are common in breast cancer survivors, and can affect adherence to treatment. We synthesised the evidence for strategies to self-manage these side-effects. Methods We searched for systematic reviews and clinical guidelines on self-management strategies for AET side-effects (arthralgia, fatigue, hot flashes, gastrointestinal discomfort, nausea, vulvovaginal symptoms, and sleep disturbance). We searched oncology organisation’s websites and eight databases (Inception-November 2020). Screening, data extraction and quality assessment were completed independently in duplicate. PROSPERO: 2019CRD4201914001. Results We identified 33 systematic reviews and 18 clinical guidelines. 21% of reviews were high quality, and the average quality score for guidelines was 44%. Evidence for most strategies was absent or weak. There was consensus from a low-quality review and multiple guidelines to recommend moisturisers, gels and lubricants for vulvovaginal symptoms. Evidence was weak for physical activity for self-managing most symptoms, although two high-quality reviews indicated yoga and aerobic exercise could reduce fatigue. Primary research was often biased by weak and underpowered study designs. Eleven reviews did not report information on adverse events. Conclusions Most self-management strategies for breast cancer survivors experiencing side-effects from AET lack evidence. Primary research is needed using high-quality well-powered designs focusing on implementable strategies. Implications for Cancer Survivors Patients and clinicians should be aware that although the risk of harm is low for these self-management strategies, the likelihood of benefit is often unclear. Women should consider moisturisers, gels or lubricants for self-managing vulvovaginal symptoms, and yoga or aerobic exercise for alleviating fatigue.

Adjuvant endocrine therapy (AET) for breast cancer reduces mortality, but one-third to one-half of patients discontinue it early or are nonadherent.We developed a pilot single-site study of patients with evidence of early nonadherence to AET to assess the feasibility of a novel, clinical pharmacist-led intervention targeting symptom and medication management.Patients with prescription fill records showing nonadherence were enrolled in a single-arm feasibility study. Automated reminders were sent by e-mail or text with a link to symptom monitoring assessments weekly for 1 month and monthly until 6 months. Clinical oncology pharmacists used guideline-based symptom management and other medication management tools to support adherence and ameliorate symptoms reported on the assessments. Patient-reported outcome assessments included physical, mental, and social health domains and self-efficacy to manage symptoms and medications. Feasibility outcomes included completion of symptom reports and pharmacist recommendations.Of 19 participants who were nonadherent who enrolled and completed initial assessments, 18 completed all final study procedures, with 14 completing all assessments and no patient missing more than 3 assessments. All 18 participants reported at least one of 3 symptom types, and the majority reported attempting pharmacist recommendations. Patient-reported measures of physical, mental, and social health and self-efficacy improved, and 44% of the patients became adherent.An intervention using pharmacists in an oncology practice to systematically monitor and manage symptoms shows promise to reduce symptoms, enhance support and self-efficacy, and improve adherence to AET.

This study aimed to examine whether inducible nitric oxide synthase (iNOS) plays a role in the delayed antiarrhythmic effect of sodium nitrite. Twenty-one dogs were infused intravenously with sodium nitrite (0.2 μmol·kg–1·min–1) for 20 min, either in the absence (n = 12) or in the presence of the iNOS inhibitor S-(2-aminoethyl)-isothiourea (AEST) (total dose 2.0 mg·kg–1 i.v., n = 9). Control dogs (n = 12) were given saline. Twenty-four hours later, all of the dogs were subjected to a 25 min period occlusion of the left anterior descending coronary artery followed by rapid reperfusion. Dogs treated with AEST and nitrite received again AEST prior to the occlusion. Compared with the controls, sodium nitrite markedly reduced the number of ectopic beats, the number and incidence of ventricular tachycardia, and the incidence of ventricular fibrillation during occlusion and increased survival (0% versus 50%) from the combined ischaemia and reperfusion insult. Although AEST completely inhibited iNOS activity, the nitrite-induced increase in NO bioavailability during occlusion was not substantially modified. Furthermore, AEST attenuated but did not completely abolish the antiarrhythmic effect of nitrite. The marked delayed antiarrhythmic effect of sodium nitrite is not entirely due to the activation of iNOS; other mechanisms may certainly play a role.

Radioprotective Effects of Quercetin and Ethanolic Extract of Propolis in Gamma-Irradiated MiceThe aim of this study was to assess radioprotective effects of quercetin and the ethanolic extract of propolis (EEP) in CBA mice exposed to a single radiation dose 4 Gy (60Co). The mice were treated with 100 mg kg-1quercetin or EEP a day for three consecutive days either before (pre-treatment) or after gamma-irradiation (therapy). Leukocyte count was determined in blood drawn from the tail vein, and DNA damage in leukocytes was assessed using the alkaline comet assay. Genotoxic effects of the test compunds were also evaluated in non-irradiated mice. The levels of radioprotection provided by both test compounds were compared with those established in mice that were given chemical radioprotector S-(2-Aminoethy1)isothiouronium bromide hydrobromide (AET). Mice that received pre-treatment were less sensitive to irradiation. Mice given the post-irradiation therapy showed a slight but not significant increase in total leukocyte count over irradiated negative control. Quercetin showed better protective properties than EEP in both pre-treatment and therapy, and activated a higher number of leukocytes in non-irradiated mice. The alkaline comet assay suggests that both natural compounds, especially when given as pre-treatment, protect against primary leukocyte DNA damage in mice. At tested concentrations, EEP and quercetin were not genotoxic to non-irradiated mice. AET, however, caused a slight but not significant increase in DNA damage. Although the results of this study show the radioprotective potential of the test compounds, further investigation is needed to clarify the underlying protection mechanisms.

This study investigated the role of nitric oxide in radiation-induced damage by examining changes in mouse serum nitrate concentrations after irradiation. In addition, the contribution of S-2-aminoethylisothiourea 2HBr (AET) to the mechanisms of radiation damage protection was also clarified. The serum nitrate concentration increased as soon as 1.5 h after irradiation, and after 2.5 to 3.0 h the concentrations were significantly higher compared with normal levels. Normal levels were re-established after 12 h. Post-irradiation serum nitrate concentrations increased dose-dependently with irradiation dose (19.6-31.5 Gy). AET suppressed increases in the serum nitrate concentration following irradiation while 2-mercaptoethylamine HCl (MEA) did not. AET has an inhibitory effect on inducible nitric oxide synthase (iNOS); therefore, the increase in nitric oxide after irradiation may be produced by iNOS. Combined administration of irradiation and lipopolysaccharide (LPS) induced a significant increase in serum nitrate concentration, and a significant decrease in survival rate, compared with irradiation alone. The administration of AET or aminoguanidine increased survival rate following irradiation. In contrast to findings after LPS administration, IL-1beta and IFN-gamma were not determined in serum following irradiation. Existing iNOS is activated by irradiation, and nitric oxide production appears to increase without iNOS induction. Thus, the irradiation-induced increase in nitric oxide may be related to lethal injury.

A model to study the effectiveness of potential chemopreventive agents that inhibit neoplastic process by different mechanisms has been used to test the efficacy of seven nitric oxide synthase (NOS) inhibitors. Five selective inducible NOS (iNOS) inhibitors: S-methyl isothiourea (S-MITU), S-2-aminoethyl isothiourea (S-2-AEITU), S-ethyl isothiourea (S-EITU), aminoguanidine (AG), 2-amino-4-methyl pyridine (2-AMP), and two non selective general NOS inhibitors: l-N(6)-(1-iminoethyl) lysine (IEL) and N(omega)-nitro-l-arginine (NNLA), were tested for efficacy against a carcinogen, benzo[a]pyrene (B[a]P)-induced primary rat tracheal epithelial (RTE) cell transformation assay. RTE cells were treated with B[a]P alone or with five nontoxic concentrations of an NOS inhibitor and the resulting foci at the end of 30 days were scored for inhibition of transformation. The results indicate that all three isothiourea compounds inhibited B[a]P-induced RTE foci in a dose-dependent manner. S-AEITU was the most effective inhibitor with an IC(50) (the molar concentration that inhibits transformation by 50%) of 9.1 microM and 100% inhibition at the highest dose tested (30 microM). However, both S-EITU and S-MITU showed a maximum percent inhibition of 81% and 100% at 1 mM with an IC(50) of 84 and 110 microM, respectively. 2-AMP did not show any dose-dependent response, but was highly effective (57% inhibition) at an intermediate dose of 30 microM and an IC(50) of 25 microM. Similar to thiourea compounds, AG exhibited good dose-dependent inhibition with a maximum inhibition of 86% at 1 mM. NNLA and IEL were negative in this assay. Based on the IC(50) values, NOS inhibitors were rated for efficacy from high to low as follows: S-2-AEITU

Nitric oxide (NO) produced by macrophages is thought to contribute to various pathological conditions. Osteopontin (OPN) is a phosphorylated glycoprotein produced principally by macrophages. OPN inhibits inducible nitric oxide synthase (iNOS), which generates large amounts of NO production. However, the relationship between NO and endogenous OPN in activated macrophages has not yet been elucidated. We therefore examined expression of endogenous iNOS and OPN in a murine macrophage cell line, RAW 264.7 cells, by treating the cells with lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma). Treatment of cells with LPS and IFN-gamma resulted in an increase of iNOS mRNA to maximum at 12 h after stimulation. In contrast, OPN mRNA was induced more slowly than iNOS mRNA. Induction of both iNOS and OPN mRNA in RAW 264.7 cells was markedly suppressed by addition of the specific iNOS inhibitor S-2-aminoethyl isothiourea dihydrobromide. The NOS inhibitor NG-methyl-L-arginine also suppressed induction of OPN mRNA but hardly affected iNOS mRNA expression. The NO-releasing agent spermine-NONOate but not peroxynitrite enhanced induction of OPN mRNA. These results suggest that NO directly up-regulates the endogenous OPN in macrophages stimulated with LPS and IFN-gamma. This up-regulation of endogenous OPN may represent a negative feedback system acting to reduce iNOS expression.

The vasodilator nitric oxide (NO) is involved in the regulation of systemic blood pressure and local organ blood flow. Inhibitors of the constitutively expressed nitric oxide synthase in endothelial cells (eNOS), e.g., Nomega-nitro-L-arginine methyl ester hydrochloride (L-NAME), aggravated liver injury in a variety of models. On the other hand, inhibitors of the inducible NOS (iNOS), e.g., 2-aminoethyl-isothiourea (AET), were found to be beneficial during endotoxemia. The aim of this investigation was to study the effect of AET compared with L-NAME on liver microvascular blood flow and injury in more complex models with multiple insults, i.e., ischemia (20 min)-reperfusion (8 h) in combination with .5 mg/kg endotoxin (IRE). Male Fisher rats were treated with 10 mg/kg AET or L-NAME and subjected to IRE. At 8 h, liver injury (plasma ALT: 1320+/-164 U/L) was significantly increased in AET-treated (5,018+/-1,379 U/L) and L-NAME-treated groups (2,429+/-228 U/L). Each inhibitor attenuated microvascular blood flow (assessed by laser Doppler flowmetry) to a similar degree. In striking contrast, AET completely reversed the endotoxin-induced impairment of the microvascular blood flow and significantly protected against an endotoxin-induced liver injury (plasma ALT: 3,007+/-268 U/L (ET); 460+/-39 U/L (ET+AET)). Infusion of endothelin-1 reduced microvascular blood flow by 50-60% and caused liver injury. Our data demonstrated that an inhibitor of eNOS (L-NAME) has a consistent detrimental effect on liver injury during ischemia-reperfusion and endotoxemia mainly because it can cause additional ischemia by reducing the microvascular blood flow. However, selective inhibitors of iNOS (AET) can impair hepatic blood flow and aggravate the injury or improve blood flow and attenuate organ injury depending on the experimental model. These results suggest that iNOS inhibitors may not be universally beneficial and should be tested in a variety of experimental models of sepsis/endotoxemia before used in clinical settings.

The role of nitric oxide (NO) in hepatic oxygen transport is unclear. We investigated the effects of aminoethyl-isothiourea (AE-ITU), a selective inhibitor of iNOS activity, on liver blood flow and oxygen consumption (VO2H) in the pig. Endotoxin (lipopolysaccharide, LPS) was given intraportally (1.7 microg/kg/h), followed by AE-ITU (10 mg/kg) after 3 h (n = 7), LPS controls (n = 8) received LPS for 6 h. AE-ITU controls (n = 6) received saline/AE-ITU. LPS (treatment group) caused significant reductions at 3 h in cardiac output (CO) from 4.4 +/- .4 to 2.7 +/- .3 L/min, in hepatic artery flow (Q(HA)) from 266 +/- 53 to 127 +/- 19 mL/min, and in portal venous flow (Q(PV)) from 630 +/- 50 to 323 +/- 33 mL/min. Hepatic oxygen delivery (DO2H) was reduced from 93 +/- 11 to 38 +/- 5 mL/min (p < .05), while hepatic oxygen extraction ratio (ERO2H) increased, and VO2H was maintained. Similar changes were observed in LPS controls. AE-ITU caused no changes in saline controls. After injection of AE-ITU during LPS infusion, CO was unchanged, while Q(HA) increased gradually from 127 +/- 20 to 268 +/- 40 mL/min over 3 h (p < .05) and DO2H from 38 +/- 5 to 60 +/- 5 mL/in (p < .05). ERO2H increased from .54 +/- .04 to .69 +/- .03 in 30 min, while VO2H increased from 23 +/- 4 to 35 +/- 3 mL/in in 3 h (p < .05). Thus, AE-ITU restored hepatic arterial blood flow and increased hepatic oxygen consumption in pigs with endotoxemia.

Endotoxin has profound effects on nitric oxide (NO) production, and considerable controversies exist as to whether these alterations are beneficial or deleterious. Increased mortality has been reported from nonselective inhibition of NO synthase. Results from selective inhibition of the inducible isoform (iNOS) appear largely positive. In a model of rat endotoxemia we have compared the early effects on hepatic morphology and function of selective and nonselective NO inhibition. Two hours after endotoxin injection (5 mg/kg intraportally) the rats were treated with either the selective iNOS inhibitor aminoethyl isothiourea (AE-ITU, 10 mg/kg), the nonselective NOS inhibitor NG-nitro-L-arginine methyl ester (L-NAME, 10 mg/kg), or normal saline. The animals were observed for another hour. Using an immunohistochemical method, induction of iNOS was demonstrated in various tissues in all slices examined. No unequivocal benefit from NO inhibition was noted. Electron microscopic examination revealed widespread alterations of liver morphology, without obvious differences between the groups. Liver function, as assessed by ketone body ratio, hepatic venous acid base values, and bile production, was generally more adversely affected after NO inhibition. Even with the iNOS selective inhibitor AE-ITU no benefit was noted. We conclude that during the early phases of endotoxemia therapeutic reduction of NO production has no positive effects on liver function or morphology.

Radioprotective effectiveness of a combination of HT and AET was evaluated by radiation induced micronucleus screening in mouse bone marrow. Swiss albino mice were injected with 2-Aminoethylisothiouronium bromide hydrobromide (AET) + 5-hydroxy-L-tryptophan (HT) 30 minutes prior to a single whole body exposure of 8 and 12 Gy Co60 gamma rays. Animals were sacrificed at different intervals viz., 24 hours, 40 hours, 72 hours and 7 days after irradiation. Slides of femur marrow were screened thoroughly for cells with micronuclei. Marked decreases in the frequency of micronuclei in irradiated mice receiving radioprotector suggested that the combination has rendered protection to bone marrow cells against 8 Gy and 12 Gy whole body gamma irradiation. Micronucleated cells count is not altered by administration of the combination alone.

In this study, we examined the regulation by putrescine, spermidine and spermine of nitric oxide (NO) biosynthesis in Arabidopsis thaliana seedlings. Using a fluorimetric method employing the cell-impermeable NO-binding dye diaminorhodamine-4M (DAR-4M), we observed that the polyamines (PAs) spermidine and spermine greatly increased NO release in the seedlings, whereas arginine and putrescine had little or no effect. Spermine, the most active PA, stimulated NO release with no apparent lag phase. The response was quenched by addition of 2-aminoethyl-2-thiopseudourea (AET), an inhibitor of the animal nitric oxide synthase (NOS) and plant NO biosynthesis, and by 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-1-oxy-3-oxide (PTIO), an NO scavenger. By fluorescence microscopy, using the cell-permeable NO-binding dye diaminorhodamine-4M acetoxymethyl ester (DAR-4M AM), we observed that PAs induced NO biosynthesis in specific tissues in Arabidopsis seedlings. Spermine and spermidine increased NO biosynthesis in the elongation zone of the Arabidopsis root tip and in primary leaves, especially in the veins and trichomes, while in cotyledons little or no effect of PAs beyond the endogenous levels of NO-induced fluorescence was observed. We conclude that PAs induce NO biosynthesis in plants.

A model to study the effectiveness of potential chemopreventive agents that inhibit neoplastic process by different mechanisms has been used to test the efficacy of seven nitric oxide synthase (NOS) inhibitors. Five selective inducible NOS (iNOS) inhibitors: S-methyl isothiourea (S-MITU), S-2-aminoethyl isothiourea (S-2-AEITU), S-ethyl isothiourea (S-EITU), aminoguanidine (AG), 2-amino-4-methyl pyridine (2-AMP), and two non selective general NOS inhibitors: l-N(6)-(1-iminoethyl) lysine (IEL) and N(omega)-nitro-l-arginine (NNLA), were tested for efficacy against a carcinogen, benzo[a]pyrene (B[a]P)-induced primary rat tracheal epithelial (RTE) cell transformation assay. RTE cells were treated with B[a]P alone or with five nontoxic concentrations of an NOS inhibitor and the resulting foci at the end of 30 days were scored for inhibition of transformation. The results indicate that all three isothiourea compounds inhibited B[a]P-induced RTE foci in a dose-dependent manner. S-AEITU was the most effective inhibitor with an IC(50) (the molar concentration that inhibits transformation by 50%) of 9.1 microM and 100% inhibition at the highest dose tested (30 microM). However, both S-EITU and S-MITU showed a maximum percent inhibition of 81% and 100% at 1 mM with an IC(50) of 84 and 110 microM, respectively. 2-AMP did not show any dose-dependent response, but was highly effective (57% inhibition) at an intermediate dose of 30 microM and an IC(50) of 25 microM. Similar to thiourea compounds, AG exhibited good dose-dependent inhibition with a maximum inhibition of 86% at 1 mM. NNLA and IEL were negative in this assay. Based on the IC(50) values, NOS inhibitors were rated for efficacy from high to low as follows: S-2-AEITU2-AMPAGS-MITUS-EITU. The data from this study identify NOS inhibitors as a novel class of chemopreventive agents that can be developed for lung cancer prevention.

The efficacy of rat skin decontamination by radioprotective agents AET and cystamine were tested. Results were compared to standard decontaminants-alcoholate, clay and fuller's earth. It was found that all the animals decontaminated with standard decontaminants had survived 4 LD50 of poison for 21 days. All the animals poisoned by 6 LD50 had survived for 1 day except for those decontaminated with alcoholate where 50% survived throughout the observation period. Alcoholate and clay protected all, and fuller's earth 70% of animals poisoned by 12 LD50, but no longer than 24 h. AET and cystamine protected all rats from 1.7 LD50 for 3 days, from 1 LD50 for 2 days, and from 2 LD50 for 1 day. When higher doses of poison were used (1.7-6.8 LD50) only partial protection was achieved. Our results support the conclusion that radioprotective agents could be convenient means for improvised decontamination of persons poisoned by sulfur mustard, so additional investigations are necessary.

Entrapment of 5-hydroxyl-L-tryptophan (HT) in erythrocyte ghost prepared by hypotonic method and high voltage electric discharge method are nearly same. Release of HT with beta-aminoethylisothiuronium bromide hydrobromide (HT + AET) in in vitro system is rapid but only a portion of the entrapped amount is released. Release of HT + AET in serum marginally increases at 2 hr. Compared to release in in vitro medium the release in serum is less. Survival studies with Swiss albino mice indicates that compared to HT alone, the combination of HT + AET shows about 9 times percentage survival. The same combination in the encapsulated form show comparable percentage survival though the amount needed is 1/200th times compared to free form.

The modulatory effect of AET (S-2-aminoethylisothio-uronium bromide hydrobromide) and WR-2721 (S-2-/3-ami-nopropylamino/ethylphosphorothioic acid) on the clastogenic activity of X-rays was assessed by the in vivo mouse micronucleus test. The frequency of micronucleated polychromatic erythrocytes (MNPCEs) in the peripheral blood of adult male Swiss mice exposed to 5 Gy X-rays alone, or treated with AET or WR-2721, at a does of 200 mg/kg body weight, 15 or 30 minutes prior to X-irradiation, respectively, was determined during a fifteen-day period. The number of micronuclei increased on day 1 post-irradiation in X-irradiated mice and declined thereafter with the frequency of MNPCEs remaining lower in the thiol pre-treated mice. A more effective protection against the clastogenic activity of X-rays in the erythropoietic system was observed after WR-2721 administration than AET application.

1. We have investigated whether (i) endotoxaemia caused by E. coli lipopolysaccharide in the anaesthetized rat causes a multiple organ dysfunction syndrome (MODS; e.g. circulatory failure, renal failure, liver failure), and (ii) an enhanced formation of nitric oxide (NO) due to induction of inducible NO synthase (iNOS) contributes to the MODS. In addition, this study elucidates the beneficial and adverse effects of aminoethyl-isothiourea (AE-ITU), a relatively selective inhibitor of iNOS activity, and NG-methyl-L-arginine (L-NMMA), a non-selective inhibitor of NOS activity on the MODS caused by endotoxaemia. 2. In the anaesthetized rat, LPS caused a fall in mean arterial blood pressure (MAP) from 117 +/- 3 mmHg (time 0) to 97 +/- 4 mmHg at 2 h (P < 0.05, n = 15) and 84 +/- 4 mmHg at 6 h (P < 0.05, n = 15). The pressor effect of noradrenaline (NA, 1 micrograms kg-1, i.v.) was also significantly reduced at 1 to 6 h after LPS (vascular hyporeactivity). Treatment of LPS-rats with AE-ITU (1 mg kg-1, i.v. plus 1 mg kg-1 h-1 starting at 2 h after LPS) caused only a transient rise in MAP, but significantly attenuated the delayed vascular hyporeactivity seen in LPS-rats. Infusion of L-NMMA (3 mg kg-1, i.v. plus 3 mg kg-1 h-1) caused a rapid and sustained rise in MAP and attenuated the delayed vascular hyporeactivity to NA. Neither AE-ITU nor L-NMMA had any effect on either MAP or the pressor effect elicited by NA in rats infused with saline rather than LPS. 3. Endotoxaemia for 6 h was associated with a significant rise in the serum levels of aspartate or alanine aminotransferase (i.e. GOT or GPT), gamma-glutamyl-transferase (gamma GT), and bilirubin, and hence, liver dysfunction. Treatment of LPS-rats with AE-ITU significantly attenuated this liver dysfunction (rise in GOT, GPT, gamma GT and bilirubin) (P < 0.05, n = 10). In contrast, L-NMMA reduced the increase in the serum levels of gamma GT and bilirubin, but not in GOT and GPT (n = 5). Injection of LPS also caused a time-dependent, but rapid (almost maximal at 2 h), increase in the serum levels of urea and creatinine, and hence, renal dysfunction. This renal dysfunction was not affected by either AE-ITU (n = 10) or L-NMMA (n = 5). In rats infused with saline rather than LPS, neither AE-ITU (n = 4) nor L-NMMA (n = 4) had any significant effect on the serum levels of GOT, GPT, gamma GT, bilirubin, creatinine or urea. 4. Endotoxaemia for 6 h resulted in a 4.5 fold rise in the serum levels of nitrite (9.13 +/- 0.77 microM, P < 0.01, n = 15), which was significantly reduced by treatment with AE-ITU (6.32 +/- 0.48 microM, P < 0.05, n = 10) or L-NMMA (5.10 +/- 0.40 microM, P < 0.05, n = 5). In addition, endotoxaemia for 6 h was also associated with a significant increase in iNOS activity in lung and liver homogenates, which was significantly reduced in lung or liver homogenates obtained from LPS-rats treated with either AE-ITU or L-NMMA. 5. Thus, AE-ITU or L-NMMA (i) inhibits iNOS activity in LPS-rats without causing a significant increase in MAP in rats infused with saline and, hence inhibition of endothelial NOS activity, and (ii) attenuates the delayed circulatory failure as well as the liver dysfunction caused by endotoxaemia in the rat. Thus, an enhanced formation of NO may contribute to the development of liver failure in endotoxic shock.

Calcium-loaded red blood cells (RBCs) previously have been shown to have an increased sensitivity to complement-mediated hemolysis and particularly to lysis mediated by the C5b-9 membrane attack complex (MAC) of complement. Because RBCs exposed to 2-aminoethylisothiouronium bromide (AET) also have been shown to be particularly sensitive to the MAC, a direct comparison of calcium-loaded and AET-treated RBCs was performed. Calcium-loaded and AET-treated RBCs shared a marked increase in sensitivity to lysis by the MAC in two different assays. However, measurements of C5b-7 and C9 binding suggested that different mechanisms were responsible. AET-treated RBCs showed an increase in C9 binding and an increased C9/C7 ratio consistent with functional loss of CD59/membrane inhibitor of reactive lysis (MIRL). In contrast, calcium-loaded RBCs had minimally increased C9 binding that resulted in C9/C7 ratios that were less than those for untreated RBCs, suggesting that CD59/MIRL inactivation had not occurred. When RBCs were incubated in acidified serum, AET-treated cells demonstrated a marked increase in C3b binding and hemolysis that was observed in neither control nor calcium-loaded RBCs. These results suggest that the underlying lesions responsible for an increase in susceptibility to complement-mediated hemolysis are different for calcium-loaded and AET-treated RBCs.

Radionuclides employed in diagnostic and therapeutic nuclear medicine impart radiation energy to tissue over an extended period of time, which depends on the physical half-life and the biological properties of the radiochemical employed. It is therefore important to examine the capacity of chemical radioprotectors to mitigate damage caused by chronic irradiation by incorporated radionuclides.Spermatogenesis in mouse testis is used as the experimental model, and spermatogonial cell survival as measured by testicular spermhead count is the biological end point. The capacity of S-(2-aminoethyl)isothiouronium bromide hydrobromide (AET) to mitigate radiation damage caused by chronic irradiation by the radiochemicals 125IUdR, H125IPDM and 210Po-citrate, is investigated.The radioprotection provided by AET is substantial and similar for both of the radioiodinated compounds with dose modification factors (DMF) of 4.0 +/- 1.2 for 125IUdR and 3.4 +/- 0.4 for H125IPDM. In contrast, the damage caused by 210Po alpha particles is protected against to a lesser degree (DMF = 2.4 +/- 0.5).The present radioprotection data for AET, in conjunction with our earlier findings for the chemical protectors cysteamine and vitamin C in the same experimental model, suggest that such compounds may be clinically useful as mitigating agents against biological damage caused by incorporated radionuclides. The observed DMFs for AET also support our earlier premise that the mechanism by which DNA-incorporated Auger emitters impart biological damage is primarily radical mediated, and hence indirect in nature.

The induction of micronucleated polychromatic erythrocytes (MNPCEs) was assessed in the bone marrow of adult male Swiss mice treated with MEA (cysteamine HCl), AET (2-aminoethylisothiouronium Br.HBr), or WR-2721 (S-2-(3-aminopropylamino)ethyl phosphorothioic acid), at a dose of 200 mg/kg body weight, and/or exposed to 6 Gy X-rays. MEA, AET, or WR-2721 was given alone or 15 min prior to X-ray exposure, and the frequency of MNPCEs was determined 24 h after the aminothiol treatment and X-irradiation of mice. A genotoxic effect was shown for MEA, AET, WR-2721, and X-rays, as well as a protective effect of the aminothiols against X-ray-induced genotoxicity in the mouse erythropoietic system. The aminothiol drugs given alone, without subsequent X-irradiation, elevated the frequency of MNPCEs, and WR-2721 appeared to be less toxic than AET and MEA. After exposure of mice to X-rays, the number of MNPCEs was distinctly increased. MEA, AET, or WR-2721 administration prior to X-irradiation resulted in a reduction of the X-ray-induced elevation of the frequency of micronuclei, but a stronger radioprotective effect was obtained following WR-2721 and AET treatment than after MEA application. So, the genotoxic and radioprotective effect of the aminothiols was dependent on the compound applied.

Radioprotective effectiveness has been evaluated by 30 day survival studies and protection to bone-marrow cells in mice after radiation exposure and this has been further established by 24 hr deoxycytidine excretion in urine of rats following 5 Gy whole body gamma irradiation and protection to superoxide dismutase enzyme in marrow cells and red blood corpuscles. Radioprotective effectiveness as well as the duration of radioprotection have been improved by the administration (ip) of hydroxylamine (20 mg/kg), a decarboxylase inhibitor, prior to the use of a combination of 5-hydroxy L-tryptophan (5-HTP, 70 mg/kg) and 2-aminoethylisothiuronium bromide hydrobromide (AET, 20 mg/kg) ip in small mammals before whole body gamma irradiation.

Effect of HT, AET and Se on mice bone marrow has been studied by counting bone marrow micronucleated cells and endogenous spleen colony count (CFU-S). Combination of HT and AET used as a radioprotector has not caused any significant variation in any of the parameter studied when administered once, it increases bone marrow micronucleated cells and decreases CFU-S slightly after daily administration for 7 days. The individual constituent of the combination administered singly does not increase micronucleated cell number. Seven consecutive doses of HT + AET and same in combination with Se enhances micronucleated cells to a higher level. Daily injection of Se alone up to 7 days also causes an increase in micronucleated cells upto same level. CFU-S pool does not show any significant change in number of bone marrow cells through out the study except in the groups where animals were treated with Se.

Different patterns of temporary changes were observed in the acid phosphatase/E.C. 3.1.3.2./activity in the spleen, liver, and kidneys expressed in nkat per 1 mg of protein, 1 g of fresh tissue, and per whole organ weight in mice exposed to 60Co gamma-rays only and those irradiated after AET (2-aminoethylisothiouronium Br.HBr) or MEA (cysteamine HCl) treatment. The extent and timing of the alterations in enzyme activity was dependent on the particular organ chosen and the thiol agent applied. AET and MEA administered before irradiation modified the effects of exposure of mice to gamma-rays on the acid phosphatase activity in the organs studied.

Rate of glycolysis in vivo at different time intervals following 8 Gy [LD100(30)] whole body gamma radiation (WBGR) was evaluated by estimating liver glycogen, blood sugar, serum lactic dehydrogenase (LDH) and blood lactic acid concentration in adult male Sprague Dawley rats. Within 1 hr of radiation exposure, a significant fall in liver glycogen was observed in rats fed food and water ad libitum. The glycogen content increased after 24 hr and had returned to control level on 7th day after radiation exposure. Blood sugar, serum LDH and blood lactate levels increased significantly as compared to non irradiated controls. Pretreatment with 5-hydroxy-L-tryptophan (5-HTP; 100 mg/kg) + 2-aminoethylisothiuronium bromide hydrobromide (AET; 20 mg/kg) ip 30 min before 8 Gy WBGR, modified these values and restored them to normal level on 7th day post-irradiation.

Differential radioprotection between normal tissues and carcinoma was observed in C3H/J mice treated with a combination of 5-hydroxy L-tryptophan (5-HTP, 100 mg/kg) and 2-aminoethylisothiuronium bromide hydrobromide (AET, 20 mg/kg). Protection to normal tissues was judged by LD50(30) and by radiation induced damage to bone marrow(BM) using clonogenic ability of blood forming stem cells (10 day CFUs) as the criteria. Pretreatment with 5-HTP + AET combination 30 min before whole body gamma radiation (WBGR) enhanced the recoveries of the number of blood forming stem cells in BM of irradiated mice after 0, 7th and 10th day of irradiation. LD50(30) for C3H/J mice was 7.3 Gy and the dose modifying factor (DMF) of 5-HTP + AET combination was 1.76. On the contrary, pretreatment with this combination did not protect the mammary carcinoma transplanted in C3H/J mice, when exposed to 80 Gy soft X-rays.

SUMMARY A study of C4 bound to human erythrocytes in vitro and in vivo has been made by immunoblotting with mouse monoclonal anti-C4c and anti-C4d and human polyclonal anti-C4d (Rodgers and Chido) following SDS-PAGE. Multi-banded patterns differentiated between C4A and C4B isotypes. Treatment of EC4b with trypsin eliminated immunoblotting but not agglutination reactions. Serum inactivation (factor I) of EC4b resulted in banding patterns similar to those obtained from patients EC4d. Treatment of EC4b membranes with NH2OH affected many of the bands, two were lost, one was markedly reduced and others had altered SDS-PAGE mobility. Interpretation of the bands has been made in terms of C4-aceeptor complexes and inactivation fragments of C4. A distinct difference in the banding of C4A and C4B isotypes has been detected.

A statistically significant decrease was found in the glycogen content expressed in mg per 1 g of both liver in groups of mice killed in the 60th and 90th minute, and skeletal muscles in those killed in the 30th, 60th, and 90th minute after MEA injection, as well as a statistically significantly reduced blood glucose concentration in a group of mice killed in the 30th minute after AET treatment.

A case of the small-cell variant of Sézary's syndrome (SS) is reported in which the SS cells lacked the surface-marker characteristics of both T- and B-cells. In particular, the SS cells failed to form E-rosettes even with a sensitive technique using 2-amino-ethylisothiouronium bromide (AET)-treated sheep red blood cells. The significance of these findings is briefly considered in relation to the existing literature.

The treatment of human lymphocytes in vitro with 5-methoxypsoralen (5-MOP) plus UV-A induces a dose-dependent increase in the SCE rate and in structural chromosome aberrations. We carried out tests to see whether the clastogenic effect of 5-MOP plus UV-A could be reduced by the anticlastogen beta-aminoethylisothiouronium (AET). The occurrence of a protective effect proved to be dependent upon the conditions of treatment. When AET was present over a long period of time (22 h) in cultures with 5-MOP, the number of breaks was reduced compared with such cultures without AET (reduction factor 0.5-0.6). On the other hand, a short period of action by AET (1.5 h) in the presence of 5-MOP produced no reduction of breaks. Posttreatment with AET (20 h) yielded an obvious protective effect (reduction factor 0.2-0.4). The possible mechanisms of the protective effect of AET are discussed.

It seems evident that cultured human lymphoid cell lines constitute an excellent tool for the biological and molecular characterization of antigens and their recognition systems. They facilitate in depth studies of cell surface antigen expression during the growth cycle and possibly of the biosynthesis of cell surface markers. They are an excellent source from which to isolate sufficient quantities of cell surface antigens to permit this characterization. Most exciting is the possibility of elucidating cell membrane structures and studying changes in membrane structures that may lead to disordered proliferation characteristic of neoplasia. Finally, it seems that cultured cells may provide excellent models for studying the mechanism of cell surface changes that are important for cellular interaction and differentiation.

The affected erythrocytes of paroxysmal nocturnal hemoglobinuria (PNH II and PNH III cells) are abnormally sensitive to complement-mediated lysis. Normal human erythrocytes chemically modified by treatment with 2-amino-ethylisothiouronium bromide (AET) have been used as models for PNH cells inasmuch as they also exhibit an enhanced susceptibility to complement. To investigate the bases for the greater sensitivity of these abnormal cells to complement-mediated lysis, we compared binding of C3 and constituents of the membrane attack complex to normal, PNH II, PNH III, and AET-treated cells after classical pathway activation by antibody and fluid-phase activation by cobra venom factor complexes. When whole serum complement was activated by antibody, there was increased binding of C3 and C9 to PNH II, PNH III, and AET-treated cells, although the binding of these complement components to PNH II and PNH III cells was considerably greater than their binding to the AET-treated cells. In addition, all of the abnormal cell types showed a greater degree of lysis per C9 bound than did the normal erythrocytes. PNH III and AET-treated cells were readily lysed by fluid-phase activation of complement, whereas normal and PNH II erythrocytes were not susceptible to bystander lysis. The greater hemolysis of PNH III and AET-treated cells in this reactive lysis system was due to a quantitative increase in binding of constituents of the membrane attack complex. This more efficient binding of the terminal components after fluid-phase activation of whole serum complement was not mediated by cell-bound C3 fragments. These investigations demonstrate that the molecular events that characterize the enhanced susceptibility of PNH II, PNH III, and AET-treated erythrocytes to complement-mediated lysis are heterogeneous.

Effect of some radioprotectors on the urinary deoxycitidine (CdR) excretion during first 24 hr after 7 Gy whole body γ-irradiation was studied in rats. The marked increase in CdR excretion due to the 5 Gy irradiation was effectively brought down to a sufficiently low level by pretreatments with (1) combination of hydroxytryptophan (HT) and β-mercaptopropionylglycine (MPG), (2) combination of HT and small dose of 2-aminoethylisothiuronium bromide hydrobromide (AET) and (3) optimum radioprotecting dose of AET. Pretreatments with MPG, HT and the low dose of AET all given singly also lowered the CdR excretion to smaller extents. None of the radioprotectors by themselves had any effect on urinary CdR excretion. The study also confirmed the earlier observation that CdR excretion in urine increased with the dose of whole body irradiation upto 6 Gy.

Treatment of normal human red cells with AET and cysteine, under suitable experimental conditions, modifies them in such a way that their behavior in in vitro hemolysis tests becomes similar to that of the erythrocytes of paroxysmal nocturnal hemoglobinuria. It is felt that alteration of the red cells is due to the -SH groups possessed by both substances. A possible mechanism of action is hypothesized.