The Prevalence of Cognitive Frailty and Its Association with Sleep duration and Depression Among Older Adults with Heart Failure

OBJECTIVES

The prevalence of cognitive frailty and its associated factors in older population with heart failure have not been extensively studied. We investigated the prevalence of cognitive frailty and its association with sleep duration and depression among older adults with heart failure.

METHODS

This secondary analysis used a cross-sectional sample with 168 older adults with heart failure from an academic tertiary care hospital in South Korea.

RESULTS

Cognitive frailty was found in 58 (34.5%) older adults with heart failure. Our main finding revealed that longer sleep durations of ≥ 8 h (adjusted odds ratio (OR) = 2.62, 95% confidence interval (CI) = 1.04-6.59) and depression (adjusted OR = 2.84, 95% CI = 1.22-6.61) predicted an increased risk of cognitive frailty.

CONCLUSIONS

Early detection on changes in sleep patterns and depression can play a crucial role in reducing the risk of cognitive frailty in patients with heart failure. Longitudinal studies are needed to explore that sleep patterns and depression are both linked to greater risk of developing cognitive frailty among older adults with heart failure.

CLINICAL IMPLICATIONS

Development of a validated instrument for cognitive frailty screening may be beneficial for older adults with heart failure to prevent adverse outcomes.

Initial Development of User-Based Quality Evaluation Questionnaire of Smartwatch Technology for Applying to Healthcare

Background

Smartwatches are a consumer wearable device offering a potential, practical, and affordable method to collect personal health data in healthy adults. For patients with chronic diseases, this would enable symptom monitoring and aid clinical decision making. Therefore, providing customized checklists to recommend smartwatches is beneficial. However, few studies have evaluated the practical functions of smartwatches and their influence on user acceptance. We aimed at developing a reliable tool to assess the quality of smartwatches from the users' perspective.

Methods

To develop the smartwatch rating scale (SWRS), we conducted a comprehensive literature review as well as reviewed relevant websites. The SWRS includes 22 items for the usability (usability, functionality, safety, material, and display) and five items for the acceptance and adoption domain (satisfaction and intention). We measured the scale's internal consistency and inter-rater reliability by evaluating seven smartwatches.

Results

The overall scale demonstrated an excellent level of internal consistency (Cronbach's alpha = 0.91), with each subscale's internal consistency above good level (0.74 ~ 0.92). Inter-rater reliability using intraclass correlation coefficients (ICC) was at good level (2-way random ICC = 0.82, 95% CI 0.09 - 0.97).

Conclusions

The SWRS is reliable, which can meet the need for assessment of smartwatch technology for utilizing in personal healthcare. Accounting for users' perspectives will help make the most of technology without impairing the human aspects of care, this study can help consumers choose a smartwatch based on their preferences and provide guidelines for developing user-friendly wearable devices aimed at health behavior changes.

Association of sleep duration and physical frailty with cognitive function in older patients with coexisting atrial fibrillation and heart failure

AIM

To investigate the associations of sleep duration and physical frailty with cognitive function in older patients with both atrial fibrillation and heart failure.

DESIGN

This study used a cross-sectional, secondary data analysis design.

METHOD

We included outpatients aged ≥ 65 years with coexisting atrial fibrillation and heart failure in South Korea. We used a sample of 176 patients (men = 100) with HF among 277 data from the parent study. The data were collected through a self-report, structured questionnaire and electronic medical record.

RESULTS

Our main finding showed that long sleep duration and physically frail status were significant predictors of cognitive impairment in older adults with both atrial fibrillation and heart failure. Healthcare providers should be aware of the importance of assessing sleep duration and physical activity in older adults with both atrial fibrillation and heart failure to prevent or delay cognitive impairment.

Perioperative risk factors for new-onset postoperative atrial fibrillation among patients after isolated coronary artery bypass grafting: A retrospective study

AIMS

Incidence of atrial fibrillation is considerably high after open heart surgery, which may prolong hospitalization and increase mortality. The aim of the present study is to investigate the perioperative risk factors for the occurrence of new-onset atrial fibrillation following isolated coronary artery bypass grafting.

DESIGN

A retrospective study.

METHODS

A total of 327 Korean patients recorded to have undergone first-time isolated coronary artery bypass grafting and no preoperative history of atrial fibrillation were included. The data were obtained from electronic health record from January 2010 to December 2019 at a tertiary care hospital. Predictors of new-onset atrial fibrillation after the surgery were identified by multivariate logistic regression analysis.

RESULTS

The incidence rate of new-onset atrial fibrillation after coronary artery bypass grafting was approximately 28.4%, and the highest occurrence rate was 44.1% on postoperative day 2. Our main finding showed that advanced age was the strongest predictor of atrial fibrillation after coronary artery bypass grafting. In addition, history of stroke and depression, chronic obstructive pulmonary disease and intraoperative use of intra-aortic balloon pump were shown to be the risk factors.

CONCLUSION

Our findings showed that approximately 28% patients had new-onset atrial fibrillation after the surgery. Healthcare professionals should proactively assess risk factors for postoperative atrial fibrillation and focus more on older adults with pre-existing comorbidities, such as stroke, depression and chronic obstructive pulmonary disease.

IMPACT

Older adults with history of stroke, depression and comorbid chronic obstructive pulmonary disease should be carefully monitored closely during perioperative period. The study highlights that early assessment of new-onset postoperative atrial fibrillation can contribute to promote the quality of nursing care and frontline nurses may be a vital role in timely detection of atrial fibrillation after surgery. Prospective studies are required to identify the mechanisms connecting perioperative risk factors for atrial fibrillation after cardiac surgery.

Perioperative risk factors for new-onset postoperative atrial fibrillation after coronary artery bypass grafting: a systematic review

Background

Postoperative atrial fibrillation (POAF) is the most common cardiac dysrhythmia to occur after coronary artery bypass grafting (CABG). However, the risk factors for new-onset POAF after CABG during the perioperative period have yet to be clearly defined. Accordingly, the aim of our systematic review was to evaluate the perioperative predictors of new-onset POAF after isolated CABG.

Method

Our review methods adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline. We searched seven electronic databases (PubMed, Embase, CINAHL, PsycArticles, Cochrane, Web of Science, and SCOPUS) to identify all relevant English articles published up to January 2020. Identified studies were screened independently by two researchers for selection, according to predefined criteria. The Newcastle–Ottawa Scale was used to evaluate the quality of studies retained.

Results

After screening, nine studies were retained for analysis, including 4798 patients, of whom 1555 (32.4%) experienced new-onset POAF after CABG. The incidence rate of new-onset POAF ranged between 17.3% and 47.4%. The following risk factors were identified: old age (p < 0.001), a high preoperative serum creatinine level (p = 0.001), a low preoperative hemoglobin level (p = 0.007), a low left ventricle ejection fraction in Asian patients (p = 0.001), essential hypertension (p < 0.001), chronic obstructive pulmonary disease (p = 0.010), renal failure (p = 0.009), cardiopulmonary bypass use (p = 0.002), perfusion time (p = 0.017), postoperative use of inotropes (p < 0.001), postoperative renal failure (p = 0.001), and re-operation (p = 0.005). All studies included in the analysis were of good quality.

Conclusions

The risk factors identified in our review could be used to improve monitoring of at-risk patients for early detection and treatment of new-onset POAF after CABG, reducing the risk of other complications and negative clinical outcomes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02224-x.

Incidence and Risk Factors of Cardio-Cerebrovascular Disease in Korean Menopausal Women: A Retrospective Observational Study using the Korean Genome and Epidemiology Study data

PURPOSE

Cardio-cerebrovascular diseases constitute the most common and fatal disease among menopausal women. However, the risk of cardio-cerebrovascular diseases in menopausal women compared to men has been underestimated, with insufficient related studies. Therefore, we examined the incidence and risk factors of cardio-cerebrovascular diseases among Korean menopausal women.

METHODS

A retrospective observational study design with secondary analysis was conducted using data from the Korean Genome and Epidemiology Study survey. We used the study's data of 1,197 menopausal women, aged 40-64 years, who did not have cardio-cerebrovascular diseases at baseline and their related data from the biennial follow-ups over 14 years. Cardio-cerebrovascular diseases were defined as hypertension, coronary artery disease, or stroke. The incidence of cardio-cerebrovascular diseases was calculated per person-years, and multivariate Cox proportional hazards models were used to determine the predictors of cardio-cerebrovascular diseases during the follow-up period.

RESULTS

Of the 1,197 cases, 264 were early or surgical menopausal women. The overall incidence of cardio-cerebrovascular diseases was 18.75 per 1,000 person-years. Early or surgical menopause (HR = 4.32, p < .001), along with family history of cardiovascular disease (HR = 1.87, p = .024), elevated blood pressure (HR = 1.79, p < .001), abdominal obesity (HR = 1.37, p = .046), or duration of menopause at the same age (HR = 1.01, p = .001), were strong predictors of cardio-cerebrovascular diseases.

CONCLUSION

Based on the results of this study, it is necessary to identify and closely monitor women with early or surgical menopause for cardiovascular and cerebrovascular diseases prevention. Also, prevention of cardio-cerebrovascular diseases through blood pressure and abdominal obesity management is vital for menopausal women.

Predictors of unplanned 30-day readmissions after coronary artery bypass graft: a systematic review and meta-analysis of cohort studies

AIMS

Coronary artery bypass graft (CABG) is one of the most performed cardiac surgery globally. CABG is known to have a high rate of short-term readmissions. The 30-day unplanned readmission rate as a quality measure is associated with adverse health outcomes. This study aimed to identify and synthesize the perioperative risk factors for 30-day unplanned readmission after CABG.

METHODS AND RESULTS

We systematically searched seven databases and reviewed studies to identify all eligible English articles published from 1 October 1999 to 30 September 2019. Random-effect models were employed to perform pooled analyses. Odds ratio and 95% confidence interval were used to estimate the risk factors for 30-day unplanned readmission. The 30-day hospital readmission rates after CABG ranged from 9.2% to 18.9% in 14 cohort studies. Among preoperative characteristics, older adults, female, weight loss, high serum creatinine, anticoagulant use or dialysis, and comorbidities were found to be statistically significant. Postoperative complications, prolonged length of hospital stay, and mechanical ventilation were revealed as the postoperative risk factors for 30-day unplanned readmission. However, intraoperative risk factors were not found to be significant in this review.

CONCLUSION

Our findings emphasize the importance of a comprehensive assessment during the perioperative period of CABG. Healthcare professionals can perform a readmission risk stratification and develop strategies to reduce readmission rates after CABG using the risk factors identified in this review. Future studies with prospective cohort samples are needed to identify the personal or psychosocial factors influencing readmission after CABG, including perioperative risk factors.

Impact of Hospital Nurses' Perception on Clinical Alarms and Patient Safety Culture on Alarm Management Practice

This study aimed to identify the impact of nurses' perception of clinical alarms and patient safety culture on alarm management. Additionally, we aimed to describe the importance of clinical alarm issues. The data were collected from 21 August to 10 September 2020. The study participants were 116 nurses working in a tertiary acute care hospital in Korea. The self-report questionnaire included general characteristics, clinical alarm issues, nurses' alarm perception, patient safety culture, and alarm management practice. The mean age of nurses was 28.04 ± 4.06 years, with 5.71 ± 4.35 years of total clinical experience. For the importance of alarm issues, frequent false alarms leading to reduced attention or response was the most important issue. Hierarchical linear regression analysis revealed that a higher level of nurses' perceived patient safety culture was the strongest predictor of better alarm management practice (p < 0.001), followed by their perception of clinical alarms (p = 0.034). In addition, female nurses (p = 0.004), charge nurses (p = 0.013), and nurses who work less than 40 h per week (p = 0.008) were more likely to work better in alarm management practice. Future studies are needed to develop standardized alarm management guidelines by improving nurses' positive perceptions of clinical alarms and patient safety culture.

The roles of health literacy and social support in improving adherence to self-care behaviours among older adults with heart failure

Aim

To describe the associations between health literacy, social support and self‐care behaviours in older adults with heart failure.

Design

A cross‐sectional descriptive study.

Methods

A total of 252 older adults were recruited from a tertiary care hospital from September 2018–February 2019. Structured questionnaires and medical record reviews were used for data collection. Two steps of hierarchical regression analysis were employed to determine the predictors of self‐care behaviours.

Results

Health literacy (β = 0.27, p < .001) and social support (β = 0.32, p < .001) were significant determinants of self‐care behaviours in older adults with heart failure. Together, they explained 22% of the variance in self‐care behaviours.

Conclusion

Health literacy and perceived social support were positively associated with self‐care behaviours among older heart failure patients. Our findings can help health professionals develop heart failure self‐care interventions to enhance health literacy skills and social support for older adults.

Gender Differences Regarding the Impact of Change in Cognitive Function on the Functional Status of Intensive Care Unit Survivors: A Prospective Cohort Study

PURPOSE

This study aimed to identify gender differences with regard to the impact of change in cognitive function on functional status 3 months after receiving critical care.

DESIGN AND METHODS

This prospective cohort study investigated 152 intensive care unit (ICU) patients. Their functional status and cognitive function were assessed using the validated Korean version of the Modified Barthel Index and Mini-Mental State Examination, respectively. Hierarchical regression was used to evaluate the impact of change in cognitive function on functional status in ICU survivors by gender.

FINDINGS

The proportion of women suffering from consistent cognitive impairment was significantly higher than that of men. Women had a rate of improvement to normal cognitive function within 3 months after discharge that was higher than that of men. Functional status 3 months after discharge was significantly lower for patients whose cognitive impairment was consistent than that for those whose cognitive function was normal. The impact of change in cognitive function on men (R² change = .28) was greater than that on women (R² change = .13).

CONCLUSIONS

Persistent cognitive impairment after critical illness had a negative effect on functional status in ICU survivors. Importantly, the negative impact of consistent cognitive impairment was greater in men than in women.

CLINICAL RELEVANCE

Early careful assessment of functional and cognitive status after critical illness is warranted. Strategies addressing the gender-specific characteristics related to cognitive improvement should also be developed.

The moderating role of acculturation mode on the relationship between depressive symptoms and health-related quality of life among international students in Korea

We examined the moderating role of acculturation mode on the relationship between depressive symptoms and health-related quality of life (HRQoL) in international students. This cross-sectional study enrolled a convenience sample of 147 international students at a university in Korea. Participants' overall HRQoL was moderate (mean = 57.2 of 80). The main and interaction effects of depressive symptoms and selected acculturation modes explained 39.9% of the variance in HRQoL. For all acculturation modes except the integration mode, as depressive symptom scores increased, HRQoL decreased. Specifically, at high depressive symptoms levels, participants with the marginalization, separation, and assimilation modes had worse HRQoL than did the integration mode, while HRQoL was similar for all acculturation modes at low depressive symptom levels. These findings suggest that future prospective intervention strategies should be considered for not only depressive symptoms levels, but also for different acculturation modes to enhance HRQoL in this population.

Relationship between the frequency of nursing activities and adverse outcomes in patients with acute coronary syndrome: A retrospective cohort study

The aim of this retrospective cohort study was to identify the relationship between the frequency of nursing activities during the first hospitalization and adverse outcomes in patients with acute coronary syndrome by using electronic health records. Patients diagnosed with acute coronary syndrome from April 2010 to April 2015 were examined for eligibility based on 36 months of major adverse cardiac events as the main outcome. Among the 652 patients who were enrolled, 66 patients experienced major adverse cardiac events. The average frequency of nursing activities was 1098.7 (±2703.8), and four variables (length of hospital stay, albumin level, hemoglobin level, and frequency of nursing activities) were significantly associated with 36 months of major adverse cardiac events. After adjusting for these variables, the frequency of nursing activities was found to be the only significant factor associated with the incidence of 36 months of major adverse cardiac events. This finding suggests that patients with acute coronary syndrome who require more frequent nursing activities during the first hospitalization could be vulnerable to adverse outcomes and should be closely monitored.

Health-Related Quality of Life and Associated Factors in Patients with Atrial Fibrillation: An Integrative Literature Review

Atrial fibrillation (AF) is a common cardiac arrhythmia associated with poor health-related quality of life (HRQoL). However, the factors influencing HRQoL in patients with AF are not well understood. The purpose of integrative review was to investigate the factors affecting HRQoL in patients with AF based on the six domains of Ferrans and colleagues’ HRQoL model. A total of 23 relevant articles published between January 2000 and March 2018 were identified using four databases and analyzed in this study. Our review showed that the HRQoL in patients with AF was consistently lower than both healthy individuals and patients with other cardiovascular diseases. The most common factor associated with HRQoL in patients with AF was anxiety-specific to AF in the symptoms domain, followed by frequency and severity of symptoms and the New York Heart Association functional class. This study highlights that monitoring and assessing patients’ symptoms is vital for improving HRQoL in patients with AF. Disease-specific and cross-culturally validated tools can allow healthcare professionals to provide tailored interventions for patients with AF.

Health Literacy but Not Frailty Predict Self-Care Behaviors in Patients with Heart Failure

Heart failure (HF) is a chronic condition requiring continuous self-care. Health literacy is increasingly recognized as a key factor of self-care behaviors in patients with chronic diseases. Recently, frailty in chronic diseases has also been associated with self-care behaviors. However, relationships among health literacy, frailty, and self-care in the HF population are not well understood. Therefore, this cross-sectional study aimed to identify the impact of health literacy and frailty on self-care behaviors in patients with HF. Data were collected from 281 adults attending a cardiovascular outpatient clinic in Korea. Health literacy, frailty, and self-care behaviors were measured using Korean-validated instruments. The mean scores of health literacy and self-care behaviors were 8.89 (±3.44) and 31.49 (±5.38), respectively. The prevalence of frailty was around 26.3%. Health literacy was significantly associated with frailty and self-care behaviors. In a hierarchical linear regression analysis, health literacy was a significant determinant of self-care behaviors after adjusting for confounding variables, but frailty was not. Educational level was also a significant predictor of self-care behaviors. Our main findings showed that health literacy can facilitate improvements in HF self-care behaviors. Healthcare professionals should assess patients’ health literacy and educational backgrounds when designing self-management programs.

The Association Between Perceived Stress and Quality of Life in University Students: The Parallel Mediating Role of Depressive Symptoms and Health-Promoting Behaviors

PURPOSE

This study examined whether depressive symptoms and health-promoting lifestyle behaviors mediate the association between perceived stress and quality of life (QoL) in university students.

METHODS

Using a cross-sectional survey, Korean university students (N = 187, M_age = 23.97 years; 54.0% Woman) completed structured questionnaires with psychometric adequacy. A parallel multiple mediation model was used to test the mediating effect of depressive symptoms and health-promoting lifestyle behaviors on the relationship between perceived stress and QoL.

RESULTS

Total effect of perceived stress, depressive symptoms, and health-promoting lifestyle behaviors on QoL was -.55. Of these, total indirect mediating effect was -.50, whereas direct effect was only -.05 in the parallel mediation model. In particular, depressive symptoms (indirect effect = -.32) and health-promoting lifestyle behaviors (indirect effect = -.18) completely mediated the relationship between perceived stress and QoL.

CONCLUSION

The results suggest that effective strategies primarily focusing on improving depressive symptoms along with health behaviors are needed to decrease the negative effect of perceived stress on QoL.

Impact of Sociodemographic and Clinical Factors on Health-Related Quality of Life in Older Adults With Atrial Fibrillation

Atrial fibrillation (AF) is more prevalent in older adults than other populations and affects health-related quality of life (HRQoL). However, few studies have investigated HRQoL and clinical factors in older adults with AF. The aim of the current cross-sectional study was to describe HRQoL using an AF-specific QoL instrument and identify factors influencing HRQoL in Korean older adults with AF. Data from 205 patients diagnosed with AF in a tertiary hospital were analyzed. Patients' mean age was 74.24 years and 43.9% of patients were female. The total HRQoL score was 49.6 of 100. The lowest score was in the physical dimension of HRQoL. Concern about lethal complications from AF was an essential concept related to QoL. In multiple linear regression, age and gender were significant predictors for the physical dimension of HRQoL. Gender and comorbidity were significant factors for the sexual activity dimension. Health care providers should help improve the HRQoL of older adults with AF by reducing physical burdens and concerns about health-related complications. [Res Gerontol Nurs. 2018; 11(4):207-215.].

Exploring the Influence of Nursing Work Environment and Patient Safety Culture on Missed Nursing Care in Korea

PURPOSE

This study aimed to explore the influence of nurse work environment and patient safety culture in hospital on instances of missed nursing care in South Korea.

METHODS

A cross-sectional design was used, in which a structured questionnaire was administered to 186 nurses working at a tertiary university hospital. Data were analyzed using descriptive statistics, t-test or ANOVA, Pearson correlation and multiple regression analysis.

RESULTS

Missed nursing care was found to be correlated with clinical career, nursing work environment and patient safety culture. The regression model explained approximately 30.3 % of missed nursing care. Meanwhile, staffing and resource adequacy (β = -.31, p = .001), nurse manager ability, leadership and support of nurses (β = -.26, p = .004), clinical career (β = -.21, p = .004), and perception on patient safety culture within unit (β = -.19, p = .041) were determined to be influencing factors on missed nursing care.

CONCLUSION

This study has significance as it suggested that missed nursing care is affected by work environment factors within unit. This means that missed nursing care is a unit outcome affected by nurse work environment factors and patient safety culture. Therefore, missed nursing care can be managed through the implementation of interventions that promote a positive nursing work environment and patient safety culture.

Depressive Symptoms and Physical Frailty in Older Adults With Chronic Heart Failure: A Cross-Sectional Study

Depressive symptoms and physical frailty have been reported to be predictive of adverse outcomes in individuals with heart failure (HF). Depressive symptoms could be a predisposing factor of physical frailty in older adults. Despite the high prevalence of HF, few studies on the relationship between these two factors have been performed in older adults with HF. To identify the relationship between depressive symptoms and physical frailty in HF, 190 older adults with HF were recruited from an outpatient clinic at a tertiary hospital in South Korea. The prevalence of depressive symptoms and physical frailty in older adults with HF was 30% (n = 57) and 61.6% (n = 117), respectively. Multivariate logistic regression revealed that depressive symptoms most strongly increased the risk of physical frailty after adjusting for confounding factors. Early detection of depressive symptoms might be useful to identify the status of physical frailty at the illness trajectories of HF in older adults and for judicious allocation of disease management strategies. [Res Gerontol Nurs. 2018; 11(3):160-168.].

Development and application of course-embedded assessment system for program outcome evaluation in the Korean nursing education: A pilot study

BACKGROUND

Program outcome evaluation is important because it is an indicator for good quality of education. Course-embedded assessment is one of the program outcome evaluation methods. However, it is rarely used in Korean nursing education.

OBJECTIVES

The study purpose was to develop and apply preliminarily a course-embedded assessment system to evaluate one program outcome and to share our experiences.

DESIGN AND SETTINGS

This was a methodological study to develop and apply the course-embedded assessment system based on the theoretical framework in one nursing program in South Korea.

DATA

Scores for 77 students generated from the three practicum courses were used.

METHODS

The course-embedded assessment system was developed following the six steps suggested by Han's model as follows. 1) One program outcome in the undergraduate program, "nursing process application ability", was selected and 2) the three clinical practicum courses related to the selected program outcome were identified. 3) Evaluation tools including rubric and items were selected for outcome measurement and 4) performance criterion, the educational goal level for the program, was established. 5) Program outcome was actually evaluated using the rubric and evaluation items in the three practicum courses and 6) the obtained scores were analyzed to identify the achievement rate, which was compared with the performance criterion.

RESULTS

Achievement rates for the selected program outcome in adult, maternity, and pediatric nursing practicum were 98.7%, 100%, and 66.2% in the case report and 100% for all three in the clinical practice, and 100%, 100%, and 87% respectively for the conference. These are considered as satisfactory levels when compared with the performance criterion of "at least 60% or more".

CONCLUSION

Course-embedded assessment can be used as an effective and economic method to evaluate the program outcome without running an integrative course additionally. Further studies to develop course-embedded assessment systems for other program outcomes in nursing education are needed.

Lack of positive effect of intravitreal bevacizumab in central serous chorioretinopathy: meta-analysis and review

PURPOSE

To review and evaluate the effects of intravitreal bevacizumab injection (IVB) in centralserous chorioretinopathy (CSC) by meta-analysis.

PATIENTS AND METHODS

Clinical controlled studies that evaluated the effect of IVB in CSC were identified through systematic searches of Embase, PubMed, and the Cochrane Central Register of Controlled Trials. Data on the best-corrected visual acuity (BCVA) in logMAR and central macular thickness (CMT) in μm at baseline and 6 months after IVB were extracted and compared with those treated by simple observation.

RESULTS

Four clinical controlled studies were included in the meta-analysis. The IVB injection group achieved better BCVA at a follow-up of 6 months. However, the analysis showed that there were no significant differences of BCVA at 6 months after injection between IVB group and the observation group (-0.02 logMAR, 95% CI -0.14 to 0.11, P=0.80). The analysis of the reduction in CMT revealed that the difference between groups was not statistically significant (-8.37 μm, 95% CI -97.26 to 80.52, P=0.85). No report assessed severe complications or side effects of IVB in patients with CSC.

CONCLUSIONS

Meta-analysis failed to verify the positive effect of IVB in CSC based on the epidemiological literature published to date.

Zizyphus jujuba and its active component jujuboside B inhibit platelet aggregation

The seeds of Zizyphus jujuba (SZJ), a famous oriental traditional medicine, have been reported to exhibit diverse activities in biological systems including the cardiovascular system. However, little information is available on its antiplatelet activity. This study was undertaken to investigate the antiplatelet effects of the ethanolic extract of SZJ (ESZJ) and of its principal components jujuboside A and B. In the in vitro platelet aggregation study, ESZJ exhibited significant and concentration-dependent inhibitory effects on collagen-, thrombin-, and AA-induced platelet aggregation. In addition, ESZJ-treated mice showed significantly the prolongation of bleeding times and the protection against thromboembolic attack. A comparison of the effects of jujuboside A and B on platelet aggregation revealed that only jujuboside B had potent inhibitory effects on collagen-, thrombin-, AA-, and ADP-induced aggregation. Jujuboside B also exhibited superior protection on thromboembolic model. Furthermore, jujuboside B had a significant inhibitory effect on collagen-induced thromboxane A2 production in rat platelets. This study describes the antiplatelet effects of ESZJ and of its active component jujuboside B, and its findings suggest that these agents be considered as components of preventive and therapeutic herbal drugs targeting cardiovascular diseases associated with platelet hyperaggregation.

Chrysophanol-8-O-glucoside, an anthraquinone derivative in rhubarb, has antiplatelet and anticoagulant activities

Rhubarb is a widely used traditional medicine and has been reported to elicit a number of biological effects including anti-inflammatory and antiplatelet effects. In the present study, we investigated the effects of anthraquinone derivatives isolated from rhubarb on platelet activity. Of four anthraquinone derivatives isolated from rhubarb examined, chrysophanol-8-O-glucoside (CP-8-O-glc) was found to have the most potent inhibitory effect on collagen- and thrombin-induced platelet aggregation. CP-8-O-glc-treated mice showed significantly prolonged bleeding times. Furthermore, CP-8-O-glc was found to have a significant inhibitory effect on rat platelet aggregation ex vivo and on thromboxane A(2) formation in vitro. In coagulation tests, CP-8-O-glc did not alter prothrombin time, and it prolonged the activated partial thromboplastin time. However, CP-8-O-glc only inhibited platelet phosphatidylserine exposure, but not exert direct inhibition on intrinsic factors. This study demonstrates the antiplatelet and anticoagulant effects of CP-8-O-glc and suggests that this compound might be of therapeutic benefit for the prevention of platelet-related cardiovascular diseases.

Antiplatelet effects of Cyperus rotundus and its component (+)-nootkatone

ETHNOPHARMACOLOGICAL RELEVANCE

Cyperus rotundus, a well-known oriental traditional medicine, has been reported to exhibit wide spectrum activity in biological systems including the circulatory system, however, little information is available on its antiplatelet activity. This study was undertaken to investigate the antiplatelet effects of Cyperus rotundus EtOH extract (CRE) and its constituent compounds.

MATERIALS AND METHODS

The antiplatelet activities of CRE and its eight constituent compounds were evaluated by examining their effects on rat platelet aggregations in vitro and ex vivo, and on mice tail bleeding times.

RESULTS

During the in vitro platelet aggregation study, CRE showed significant and concentration-dependent inhibitory effects on collagen-, thrombin-, and/or AA-induced platelet aggregation. Of its eight components, (+)-nootkatone was found to have the most potent inhibitory effect on collagen-, thrombin-, and AA-induced platelet aggregation. In addition, CRE- and (+)-nootkatone-treated mice exhibited significantly prolonged bleeding times. Furthermore, (+)-nootkatone had a significant inhibitory effect on rat platelet aggregation ex vivo.

CONCLUSIONS

This study demonstrates the antiplatelet effects of CRE and its active component (+)-nootkatone, and suggests that these agents might be of therapeutic benefit for the prevention of platelet-associated cardiovascular diseases.

A case of biphenotypic blast crisis of unclassified myeloproliferative disorder

We report a first case of biphenotypic blast crisis of unclassified myeloproliferative disorder (MPD). A 20-year-old patient presented with fever, splenomegaly, marked leukocytosis (603 x 10(3)/ micro l), and blasts in the peripheral blood. Since Ph chromosome and bcr-abl gene rearrangement were absent, the diagnosis of an unclassified MPD in the blast crisis phase was established. Immunophenotyping confirmed a biphenotypic crisis of myeloid and T-lymphoid antigens. The patient went into a complete remission after chemotherapy, but marked granulocytic hyperplasia (M:E ratio of 5.7) and 90% cellularity remained. Blast crisis recurred during subsequent intensification chemotherapy and the patient did not go into a complete remission regardless of the intense chemotherapy. The blast crisis transformed from unclassified MPD had a grave prognosis as it responded poorly to chemotherapy. This unique blast crisis is distinguishable from the blast crisis of chronic myelogenous leukemia.

Interaction of blood components with heparin-immobilized polyurethanes prepared by plasma glow discharge

The blood compatibility of poly(ethylene oxide) (PEO)-grafted and heparin (Hep) immobilized polyurethanes was investigated using in vitro plasma recalcification time (PRT), activated partial thromboplastin time (APTT), platelet adhesion and activation, and peripheral blood mononuclear cell (PBMC) adhesion and activation. In the experiment with plasma proteins, the PRT of the polyurethane (PU) surface was prolonged by PEO grafting and further prolonged by heparin immobilization. The APTT was prolonged on PU-Hep, suggesting the binding of immobilized heparin to antithrombin III. The percentage of platelet adhesion on PU was not much different from that on acrylic acid- and PEO-grafted PUs (PU-C, PU-6, PU-33), yet was substantially decreased by heparin immobilization (PU-6-Hep, PU-33-Hep). The release of serotonin from adhering platelets was slightly suppressed on PEO-grafted PUs yet significantly suppressed on heparin-immobilized PUs. In the PBMC experiments, the adhesion and activation of the cells were significantly suppressed on heparin-immobilized PUs, and the amount of interleukin-6 (IL-6) released from PBMCs stimulated with surface-modified PUs decreased with a decrease in PBMC adhesion.

Role of the connectivity of secondary structure segments in the folding of alpha(1)-antitrypsin

The native form of serpins (serine protease inhibitors) is metastable, which is critical to their biological functions. Spontaneous conversion from the native form of serpins into a more stable conformation, called the "latent" form, is restricted. To examine whether the connectivity of strand 1 of beta-sheet C to the hydrophobic core is critical to the serpin's preferential folding to the metastable native conformation, we designed a circularly-permuted mutant of alpha(1)-antitrypsin, the prototype serpin, in which strand 1C is disconnected from the hydrophobic core. Conformation of the circular permutant was similar to that of the latent form, as revealed by equilibrium unfolding, limited proteolysis, and spectroscopic properties. Our results support the notion that rapid folding of the hydrophobic core with concomitant incorporation of strand 1C into beta-sheet C traps the serpin molecule into its native metastable conformation.

Juxtaglomerular cell tumor of the kidney: a case report

We report a case of renin-secreting juxtaglomerular cell tumor which developed in a hypertensive 47-yr-old Korean man. Presumptive clinical diagnosis was made before surgery based on the high level of plasma renin and the radiologic evidence of renal mass. Grossly, a round, bulging, well-encapsulated mass of 3 x 3 cm was located in the mid-portion of the right kidney. On microscopic examination, the tumor was composed of ovoid to polyhedral cells with bland nuclei, indistinct nucleoli and light eosinophilic cytoplasm. The immunostaining for renin showed strong positivity in the cytoplasm of tumor cells. The characteristic rhomboid shaped renin protogranules were observed in ultrastructural analysis.

A 2.1 A resolution structure of an uncleaved alpha(1)-antitrypsin shows variability of the reactive center and other loops

Serpin (serine protease inhibitor) proteins are involved in diverse physiological processes including inflammation, coagulation, matrix remodeling, and cell differentiation. Deficiency of normal serpin functions leads to various hereditary diseases. Besides their clinical importance, serpin proteins draw much attention due to the large conformational changes that occur upon interaction with proteases. We present here the crystal structure of an uncleaved alpha(1)-antitrypsin determined by the multiple isomorphous replacement method and refined to 2.1 A resolution. The structure, which is the first active serpin structure based on experimental phases, reveals novel conformations in the flexible loops, including the proximal hinge region of the reactive center loop and the surface cavity region in the central beta-sheet, sheet A. The determined loop conformation explains the results of recent mutagenesis studies and provides detailed insights into the protease inhibition mechanism. The high-resolution structure of active alpha(1)-antitrypsin also provides evidence for the existence of localized van-der-Waals strain in the central hydrophobic core.

Ontogeny of natural killer cells and T cells by analysis of BCR-ABL rearrangement from patients with chronic myelogenous leukaemia

Chronic myelogenous leukaemia (CML) is a haematological malignant disorder characterized by the Philadelphia chromosome (Ph) and BCR-ABL gene rearrangement. This abnormal fusion gene can be considered to serve as a marker for the transformed cell clone in CML and is found in all cells arising from the same malignant precursor cell. It has been detected in CML cells of the myeloid, monocytic, erythroid and B-lymphocytic lineages. However, it is still arguable as to whether T lymphocytes or natural killer (NK) cells carry this marker. Answering this question would clarify the ontogenic relationship between NK cells and T cells. We examined 12 CML patients and studied the expression of BCR-ABL rearrangement by fluorescence in situ hybridization (FISH) in both NK cells and T cells sorted by flow cytometry. The purity of T cells was 95.6-99.8% and that of NK cells was 95.3-99.3% after sorting. Neither NK cells nor T cells showed any positive BCR-ABL signal with the exception of one patient who recovered from a lymphoid blastic crisis. We speculate that T cells and NK cells originate from BCR-ABL-negative stem cells.

p53 gene mutations in Bowen's disease in Koreans: clustering in exon 5 and multiple mutations

We analyzed the p53 protein expression and gene mutations to evaluate the role of ultraviolet radiation or other carcinogens, and possible racial differences in 17 samples from 12 Korean patients with Bowen's disease. A simple microdissection technique was used to collect the tumor cells selectively. p53 protein expression was found in eight of 17 (47%) samples. Abnormalities in polymerase chain reaction (PCR)-single-strand conformation polymorphism (SSCP) analysis were observed in 16 (94%) samples. A total of 14 missense mutations were detected in eight (47%) samples; 11 were clustered in exon 5 and the remaining three were located in exon 8. UV-like mutations were seen in five of 14 (36%) mutations, but no CC to TT transitions, UV-fingerprint mutations were observed. Multiple mutations were present in two cases and double mutation in a single case. Each lesion in multiple Bowen's disease showed different mutations and was suggested to be of different clonal origins. TP53-loss of heterozygosity (LOH) was detected in four out of 15 (27%) informative samples. Clustering of mutations in exon 5 suggests the role of another carcinogen in Koreans or Asians other than the UVR. Microdissection would increase the detection rate of the p53 gene mutations and LOH not only in skin cancer but also in precancerous lesions.

Distribution of the native strain in human alpha 1-antitrypsin and its association with protease inhibitor function

Serine protease inhibitors (serpins) are metastable in their native state. This strain, which is released upon binding to target proteases, is essential for the inhibitory activity of serpins. To understand the structural basis of the native strain, we previously characterized stabilizing mutations of alpha(1)-antitrypsin, a prototypical inhibitory serpin, in regions such as the hydrophobic core. The present study evaluates the effects of single point mutations throughout the molecule on stability and protease inhibitory activity. We identified stabilizing mutations in most secondary structures, suggesting that the native strain is distributed throughout the molecule. Examination of the substitution patterns and the structures of the mutation sites revealed surface hydrophobic pockets as a component of the native strain in alpha(1)-antitrypsin, in addition to the previously identified unusual interactions such as side chain overpacking and cavities. Interestingly, many of the stabilizing substitutions did not affect the inhibitory activity significantly. Those that affected the activity were confined in the regions that are mobilized during the complex formation with a target enzyme. The results of our study should be useful for designing proteins with strain and for regulating the stability and functions of serpins.

Myelodysplastic syndrome that progressed to acute myelomonocytic leukemia with eosinophilia showing peculiar chromosomal abnormality: a case report

Myelodysplastic syndrome is a closely related group of acquired bone marrow disorders characterized by ineffective and dysplastic hematopoiesis. These clonal disorders frequently progress to acute leukemia. Acute myelomonocytic leukemia with eosinophilia is characterized by an increase in abnormal eosinophils in the bone marrow, relatively good clinical course and inv (16) chromosomal abnormality. We experienced one case of refractory anemia with excess blasts which progressed to refractory anemia with excess blasts in transformation and finally to acute myelomonocytic leukemia with eosinophilia showing peculiar chromosomal abnormalities of der (1;7).

Nasal angiocentric lymphoma with hemophagocytic syndrome

OBJECTIVES

Hemophagocytic syndrome (HS) is a fatal complication of nasal angiocentric lymphoma (AL) and difficult to distinguish from malignant histiocyosis. Epstein-Barr virus (EBV)-associated HS is frequently observed in lymphoma of T-cell lineage and EBV is highly associated with nasal AL. Clinicopathologic features of 10 nasal ALs with HS were reviewed to determine the clinical significance and the pathogenetic association with EBV.

METHODS

Ten patients of HS were identified from a retrospective analysis of 42 nasal ALs diagnosed from 1987 to 1996. Immunohistochemical study and in situ hybridization were performed on the paraffin-embedded tumor specimens obtained from 10 patients. Serologic study of EBV-Ab was performed in 3 available patients.

RESULTS

Five patients had HS as initial manifestation, 3 at the time of relapse and 2 during the clinical remission of AL. Four patients were treated by combination chemotherapy (CHOP) and others had only supportive care. The median survival of all patients with HS was 4.1 months (range 2 days-36.5 months) and all had fatal outcome regardless of the treatment-modality. All cases were positive for UCHL1 (CD45RO) and EBV by EBER in situ hybridization. The data of serologic tests indicated the active EBV infection.

CONCLUSIONS

HS is a fatal complication of nasal AL and has a high association with EBV. Reactivation of EBV may contribute to HS and further investigation of predictive factors and effective treatment of HS should be pursued in the future.

Metastability in the inhibitory mechanism of human alpha1-antitrypsin

Metastability of the native form of proteins has been recognized as a mechanism of biological regulation. The energy-loaded structure of the fusion protein of influenza virus and the strained native structure of serpins (serine protease inhibitors) are typical examples. To understand the structural basis and functional role of the native metastability of inhibitory serpins, we characterized stabilizing mutations of alpha1-antitrypsin in a region presumably involved in complex formation with a target protease. We found various unfavorable interactions such as overpacking of side chains, polar-nonpolar interactions, and cavities as the structural basis of the native metastability. For several stabilizing mutations, there was a concomitant decrease in the inhibitory activity. Remarkably, some substitutions at Lys-335 increased the stability over 6 kcal mol-1 with simultaneous loss of activity over 30% toward porcine pancreatic elastase. Considering the location and energetic cost of Lys-335, we propose that this lysine plays a pivotal role in conformational switch during complex formation. Our current results are quite contradictory to those of previously reported hydrophobic core mutations, which increased the stability up to 9 kcal mol-1 without any significant loss of activity. It appears that the local strain of inhibitory serpins is critical for the inhibitory activity.

Synthesis and characterization of heparinized polyurethanes using plasma glow discharge

Polyurethanes (PU) were synthesized from 4,4'-diphenylmethane diisocyanate and polytetramethylene glycol, and subsequently with ethylene diamine as a chain extender. The PU film was exposed to oxygen plasma glow discharge to produce peroxides on the surfaces. These peroxides were then used as catalysts for the copolymerization of acrylic acid (AA) and methyl acrylate (MA) in order to prepare carboxyl group-introduced PU (PU-C). Heparin-immobilized PU was prepared using the coupling reaction of PU-C with polyethylene oxide (PEO) followed by the reaction of grafted PEO with heparin. The surface-modified PUs were then characterized by attenuated total reflection Fourier transform infrared spectroscopy, electron spectroscopy for chemical analysis (ESCA), and a contact angle goniometer. The concentration of carboxylic acid groups on the PU surfaces could be controlled within the range of 0.47-1.68 micromol cm(-2) by the copolymerization of AA and MA. The amounts of heparin coupled to terminus amino groups on PU-6 and PU-33 were 1.30 and 1.16 microg cm(-2), respectively. The water contact angle of the PU was decreased by AA grafting, and further decreased by PEO grafting and heparin immobilization, showing an increased hydrophilicity of the modified PUs. A 3% loss from the originally bound heparin appeared within several hours and thereafter almost no heparin was released when heparin-immobilized PUs were immersed in a physiological solution for 100 h, indicating the covalent immobilization of heparin on the surfaces.

Low prevalence of activated protein C resistance and coagulation factor V Arg506 to Gln mutation among Korean patients with deep vein thrombosis

Activated protein C (APC) is a naturally occurring anticoagulant that interacts with factor V and VIII to inhibit the clotting cascade. The prevalence of APC resistance among Korean patients with deep vein thrombosis is ill defined. The aim of the present study was to investigate the prevalence of APC resistance and factor V Leiden mutation in Korean patients with deep vein thrombosis. The presence of factor V Leiden mutation was determined in 49 patients who visited Asan Medical Center. APC ratio was performed in 33 individuals from the above 49 patients. Three patients were excluded from the analysis because their baseline aPTT was prolonged. Resistance to APC was diagnosed when the APC ratio was below 2.55. APC resistance was documented in 8 individuals, representing 27% (8/30) of the patients on whom APC resistance test was performed. The 2 patients, who showed APC resistance, were positive for lupus anticoagulant. None of the 49 patients demonstrated factor V Leiden mutation. These findings indicate that factor V Leiden mutation is rare and APC resistance is less prevalent in Korean patients with deep vein thrombosis than in Caucasians. APC resistance not caused by factor V Leiden mutation may be a risk factor for deep vein thrombosis in this population.

Evidence of genetic progression in human gastric carcinomas with microsatellite instability

Mutator phenotype tumors provide unique opportunities to unravel malignant progression because of various gene alterations acquired during clonal tumor evolution. Gastric carcinomas, which have been known to show frequent genetic instability, would be composed of initial gene alterations shared by most tumor areas and subsequent alterations restricted to particular tumor sites. To analyse the timing of genetic events, we examined separate sites of tumor tissue obtained from a given gastric carcinoma patient with microsatellite instability (MSI). Our study included 95 normal/tumor area pairs from 25 patients. Six of the 25 patients (24%) demonstrated various levels of MSI ranging from 7% (two of 30) to 97% (28 of 29) of markers tested in multiple tumor sites. Of the six patients, five manifested frameshift mutations in a tract of ten deoxyadenosines within transforming growth factor beta receptor type II and four demonstrated frameshift mutations in a tract of eight deoxyguanosines within BAX. These mutations were common to all tumor sites regardless of the various level of MSI phenotype, indicating initial events. Two of the six patients exhibited frameshift mutations in mononucleotide repeats of mismatch repair genes, hMSH3 and hMSH6, and the insulin-like growth factor II receptor in restricted tumor areas, indicating additional alterations. Insulin-like growth factor II receptor mutations appear to be caused by hMSH3 and hMSH6 mutations because the former mutations were confined to tumor portions with the latter two mismatch repair lesions. These results provide genetic progression evidence for gastric carcinomas of the mutator pathway. In this pathway, mismatch repair insufficiency initially targets mononucleotide tracts of transforming growth factor beta receptor type II and BAX. During tumorigenesis, primary mismatch repair failure may give rise to the secondary mismatch repair lesions, frameshift mutations of hMSH3 and hMSH6, which result in another tumorigenic mutation in the insulin-like growth factor II receptor.

Microsatellite instability-associated mutations associate preferentially with the intestinal type of primary gastric carcinomas in a high-risk population

Most colon cancers exhibiting microsatellite instability (MI), a mutator phenotype of mismatch repair failure, are associated with mutations of the transforming growth factor-beta receptor type II genes (TGF-beta RII). Of intestinal- and diffuse-type gastric carcinomas, the former have been thought to arise from intestinal metaplasia in which gastric mucosa resembles intestinal mucosa. To evaluate the preferential histological type of MI-associated mutations in the development of gastric carcinoma, mutations of TGF-beta RII, p53, and p16 were analyzed for the two types of primary gastric carcinomas showing MI. Of 50 primary gastric carcinomas, including 33 intestinal types and 17 diffuse types, 15 cases (30%) demonstrated MI at 1 or more of the 11 microsatellite markers tested. The 15 MI cases were classified into two groups, widespread MI and low-level MI, based on the number of markers exhibiting the instability. Eleven were widespread MIs, and the remaining four cases were low-level MIs. Ten of the 11 (91%) widespread MIs were of the intestinal type, and 1 case (9%) was of the diffuse type. Of the 11 widespread MIs, 10 cases (91%) demonstrated frameshift mutations within the polyadenylate tract of the TGF-beta RII. The frameshift mutation was rarely detected at p53 and p16 (1 of 11, 9%). In contrast, the four low-level MI cases had no frameshift mutations within the repeat sequences of TGF-beta RII, p53, and p16, but two of the four cases demonstrated base substitution mutations within p53. Our results suggest that mismatch repair failure can mutate the TGF-beta RII and may provide one of the pathways for the development of the intestinal-type gastric carcinoma in high-risk populations.

Ovarian serous cystadenoma associated with Sertoli-Leydig cell tumor--a case report

We Describe a case of ovarian serous cystadenoma having Sertoli-Leydig cell tumor, well differentiated, in the cystic septum. Well differentiated Sertoli-Leydig cell tumor coexisting with other tumor, including serous tumor, has not yet been described. In all cases of Sertoli-Leydig cell tumor with heterologous components or other tumors, the androblastomatous components are intermediately or poorly differentiated. The present case revealed a well differentiated Sertoli-Leydig cell tumor arising in a septum of serous cystadenoma, as a circumscribed nodule. With these findings, we discuss the possibility of this Sertoli-Leydig cell tumor, considered a mural nodule, which is well established in cystic common epithelial tumors of the ovary.

p53 protein overexpression and allele loss of p53 gene in gastric adenocarcinoma

Gene alterations of p53 tumor suppressor gene such as point mutations, deletions or insertions occur in various human cancers. p53 protein overexpression was studied immunohistochemically in 80 gastric adenocarcinomas using an anti-human p53 antibody (Pab 1801) and the avidin-biotin-peroxidase technique. We have also analyzed allele loss of the human p53 gene in 54 cases of gastric adenocarcinoma using polymerase chain reaction and restriction fragment length polymorphism. p53 immunostaining was also demonstrated in 48 of 80 carcinomas (60%). Normal mucosa was always negative. No relation could be found between p53 immunostaining and the degree of differentiation. 21 of the 54 patients(39%) were informative for the p53 exon 4. In ten of these informative cases(47.6%), tumor DNAs showed allele loss when compared with nonmetastatic lymph node DNAs. Seven of the ten(70%) showed p53 immunoreactivity. These findings suggest that mutations of the p53 gene may play a role in the development of gastric adenocarcinoma and that allele loss of p53 frequently occurs in p53 immunoreactive gastric adenocarcinoma.

A case of primary hepatic actinomycosis

Actinomycosis is a chronic suppurative and granulomatous disease characterized histologically by sulfur granules with extensive necrosis, fibrosis and sinus formation. Depending on the site of primary infection, actinomycosis is generally classified as cervicofacial, thoracic and abdominal type. The liver is known to be the primary site of infection in 15% with abdominal actinomycosis. The authors have experienced a case of liver abscess in a 24-year-old male. The sono-guided aspiration biopsy revealed findings of infiltration of neutrophils and characteristics sulfur granules by light microscopy. This case was thought to represent an instance of liver actinomycosis. Although there have been a lot of reports on actinomycosis of the liver in other countries, only 3 cases were reported in Korea.

Effect of ursodeoxycholic acid on experimental hepatic porphyria induced by griseofulvin

Griseofulvin(GF) has become the drug of choice as an antifungal agent for patients who suffer from many kinds of fungal infection. In order to clarify hepatic injury by griseofulvin(GF) overload and the effect of UDCA on GF-induced hepatic injury, the authors carried out biochemical, histologic, and ultrastructural studies of liver following treatment with griseofulvin and ursodeoxycholic acid(UDCA) in mice. Urine porphobilinogen excretion in the group treated with GF alone was significantly increased and reached the highest level in the 4th week and declined thereafter. Biochemical studies of the liver function showed no remarkable changes of serum bilirubin levels throughout the experimental period in all groups, except for SGPT and alkaline phosphatase activities which were significantly elevated and reached the highest level in the second week. Then they slightly decreased in GF treated groups(GF alone and GF plus UDCA) in comparison with the control group. Pathologic findings in the group treated with GF alone include focal liver cell necrosis(esp, zone 3), Mallory bodies in hepatocytes(esp, zone 1), Kupffer cell activation, and brown protoporphyrin pigments in the hepatocytes, bile canaliculi and interlobular bile ducts with a marked inflammatory cell infiltration in the portal tracts. Under the polarizing light microscope, bile ductular and canalicular thrombi showed a "Maltese cross" birefringence in mice treated with GF alone. There is no definite finding of fatty change in hepatocyte. Under the microscope, the liver appeared normal with an intact lobular architecture in the GF plus UDCA treated group. Electron microscopically, GF-induced changes include swelling of mitochondria, globular protoporphyrin crystals in the hepatocyte cytoplasm, markedly dilated bile cannaliculi and bile ducts and the formation of a Mallory hyaline bodies in the hepatocytes. There were no noticeable structural changes in the GF plus UDCA-treated group. Therefore the results suggest that GF causes hepatic injury, namely porphyria and cholestasis, and the treatment of UDCA may have cytoprotective and choleretic effects on GF-induced hepatic injuries.

Dietary modulation of the progression of nephropathy in aging rats: an evaluation of the importance of protein

Chronic nephropathy involving glomerular sclerosis markedly progresses in severity with age in male Fischer 344 rats fed ad libitum. Restricting food intake by 40% almost totally prevents progression of these lesions. Restricting food intake by 40% without restricting protein intake is also highly effective although somewhat less so than food restriction that includes protein restriction. These findings indicate that reducing the intake of protein is not the major reason for the retardation by food restriction of the age-associated progression of nephropathy in rats.

Influence of the restriction of individual dietary components on longevity and age-related disease of Fischer rats: the fat component and the mineral component

The influence of restricting either the fat or the mineral component of the diet to the same extent as they are restricted in the life-prolonging, food-restriction paradigm but without restricting calories was studied in regard to longevity and age-related pathologic lesions of barrier-maintained male Fischer 344 rats. Neither the restriction of fat nor the restriction of mineral influenced the median length of life or maximum life span as indicated by the age of the 10th percentile survivors. Restricting the dietary fat did retard the development of chronic nephropathy and associated lesions, but it also increased the prevalence of lymphoma and leukemia. The development of chronic nephropathy was not significantly affected by restricting the mineral component of the diet.

The influence of dietary protein source on longevity and age-related disease processes of Fischer rats

The influence of replacing dietary casein with soy protein on longevity and age-related pathologic lesions of male Fischer 344 rats was investigated. Caloric intake and body weights were similar for rats on the two diets. Rats on the soy protein-containing diet had a median length of life of 844 days compared to 730 days for those on the casein-containing diet (p less than .002), and the ages of the 10th percentile survivors were 937 and 857 days, respectively (p less than .02). The progression of chronic nephropathy was markedly retarded by replacing casein with soy protein. Only 7% of the rats dying spontaneously on the soy protein-containing diet exhibited end-stage chronic nephropathy compared to 41% of the rats on the casein-containing diet. Clearly, the soy protein-containing diet enables ad libitum fed male Fischer 344 rats to be used as a model for aging research without the occurrence of renal failure as a major confounding problem.